How long does the Atlantic Rain Forest take to recover after a disturbance? Changes in species composition and ecological features during secondary succession

We evaluated floristic and ecological changes in plant communities after disturbance in Southern Atlantic Rain Forests, in the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. We compiled data for 410 tree species from 18 forests ranging from 4 to 120 years after disturbance, and classified them by dispersal mode (animal vs. non-animal), successional group (pioneer vs. non-pioneer), vertical position (understorey vs. non-understorey) and geographic distribution (Atlantic Forest vs. widespread). We found that both geographical location and time since disturbance affect species distribution and β-diversity. Regression analyses showed significant, positive and strong relations (0.26 ? r² ? 0.63; P < 0.05) between fragment age and species richness, proportion of animal dispersed species, of non-pioneer species, of understorey species and with restricted distribution. Applying our data to values found in literature we predict that a forest needs about one to three hundred years to reach the proportion of animal-dispersed species (80% of the species), the proportion of non-pioneer species (90%) and of understorey species (50%) found in mature forests. On the other hand much more time is necessary (between one and four thousand years) to reach the endemism levels (40% of the species) that exist in mature forests. Our findings indicate that disturbance results in significant changes in species composition (decrease in endemic species) and ecological guilds (decrease in zoochory and in non-pioneer and understorey species), but forests can gradually recover over time spans of hundreds of years.     

A proposal of clinical breakpoints for amoxicillin applicable to porcine respiratory tract pathogens

In the present position paper, an attempt was made to establish clinical breakpoints of amoxicillin to classify porcine respiratory tract pathogens as susceptible, intermediate or resistant based on their minimum inhibitory concentrations of amoxicillin. For this, a thorough review of the published literature with regard to swine-specific pharmacological data (including dosages of amoxicillin applied and routes of administration used), clinical efficacy, and in vitro susceptibility of the target pathogens was performed. Based on the comparative analysis of the results, the working group "Antibiotic Resistance" of the German Veterinary Medical Society (DVG) proposed to classify porcine respiratory tract pathogens that show MIC values of amoxicillin of < or =0.5microg/ml as "susceptible", those with MICs of 1microg/ml as "intermediate", and those with MICs of > or =2microg/ml as "resistant".     

Longevity summary from 69 years of Estrildidae ringing data in southern Africa

This study focuses on the longevity data accumulated for the family Estrildidae, specifically exploring longevity records for each species using ringing data. Longevity is the minimum age reached by an individual as determined by the time elapsed between initial ringing and last recapture or recovery date. In southern Africa bird ringing started in 1948 and is managed by the South African Bird Ringing Scheme. For estrildids, there are 151 831 ringing records. Approximately 7.0% of those ringed individuals have since been resighted, retrapped or recovered. This family is poorly studied and more research is necessary, particularly as certain estrildid species have been highlighted as data-deficient whilst others are potentially of conservation concern. The South African Bird Ringing scheme (SAFRING) has longevity records for 23 of the 27 southern Africa estrildid species. The maximum longevity record was 10.9 years (Blue Waxbill Uraeginthus angolensis). The overall average longevity for an individual is 3.7 years (SD = 2.5). The low longevity values make sense given the low mass (6.3–22.7 g) of estrildids. Coupled with large clutch sizes of four eggs on average, as well as potentially low surivival, estrildids may counter low longevity by breeding at an early age and double-brooding.     

Effect of disinfection with peracetic acid on the microbial community of a seawater aquaculture recirculation system for Pacific white shrimp (Litopenaeus vannamei)

When tropical shrimps are kept in recirculating aquaculture systems (RAS), one of the limiting factors is the maintenance of a sufficient water quality, and therefore, often disinfectants like peracetic acid (PAA) are added to the water either as prophylactic or treatment measure. In this study, PAA in concentrations of 0.1 mg/L, 1 mg/L and 10 mg/L was applied continuously for 56 days to small-scale seawater RAS stocked with Litopenaeus vannamei. Treatment with 0.1 mg/L did not result in a reduction in the total bacterial amount and therefore was not effective. A concentration of 10 mg/L led to significant changes in the chemical water parameters already after 2 days and was therefore not recommendable. A concentration of 1 mg/L led to increased levels of ammonia and nitrite within 2 days and to a significant increase in the bacterial amount in the water, most probably due to an enhanced growth of heterotrophic bacteria. The microflora showed significant fluctuations, and there were indications that the welfare of the shrimps was affected. Using 1 mg PAA/L for prophylactic use is therefore also not recommendable but might be an alternative option for short-term treatment in cases of disease outbreaks.     

Koi herpesvirus and carp edema virus threaten common carp aquaculture in Croatia

Common carp (Cyprinus carpio) is a very important fish species for warm-water aquaculture in Croatia. All Croatian carp farms are subjected to a surveillance programme for the presence of koi herpesvirus (KHV), causing a deadly disease called koi herpesvirus disease (KHVD). However, there is no surveillance for other viral pathogens of importance like carp edema virus (CEV), a causative agent of koi sleepy disease (KSD). During regular testing within the KHVD surveillance programme, we tested samples for CEV simultaneously. The screening indicated possible outbreaks of KHVD and KSD. During 2016, KHVD broke out in an isolated area and soon thereafter a KHV eradication programme was successfully performed. However, during 2018 and 2019, two additional mortality events occurred in lakes in the southern part of Croatia during the spring. Samples from both events tested positive for CEV. An epidemiological investigation confirmed the introduction of infected carps from an infected farm to one of the lakes. To prevent the spreading of CEV into open waters, it is of utmost importance to introduce CEV testing before fish movement or to perform regular testing of all carp farms in the country to determine CEV prevalence for the purpose of implementation of control measures.     

Thermal and oxidation protection of carbon fiber by continuous liquid phase pre-ceramic coatings for high temperature application

Thermal and oxidation resistant coating is necessary for carbon fiber (CF) in CF reinforced concrete (CFRC) composite application in order to fulfil a high level of safety standard in case of fire. Pre-ceramic coatings such as Polysilazane, Polysiloxane, and Methyl silicone resin have been deposited on CF filament yarn by means of wet chemical continuous dip coating method. The surface analyses e.g. scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) results showed the changes of surface morphology by the coatings. Thermo gravimetric analysis (TGA) revealed that the high temperature (up to 800 °C) oxidation stability of CF was significantly improved with coatings. Thermo-mechanical properties also significantly enhanced up to 600 °C. CF yarn retains its original strength and elasticity modulus/stiffness at 700 °C due to thermal and oxidation resistant coatings.     

Organic‐carbon fractions in an agricultural topsoil assessed by the determination of the soil mineral surface area

According to recent conceptual models, the organic carbon (OC) of soils can be divided into OC fractions of increasing stability from labile free OC to resistant OC associated with the soil mineral phase. In this study, we present a method for quantifying two OC fractions based on soil aggregate–size fractionation and the N₂ gas–adsorption method. For this purpose, we analyzed soil material of the plow layer of a Haplic Chernozem subjected to different fertilizer treatments (no fertilizer, mineral fertilizer, mineral and organic fertilizer). The total organic‐C concentration (TOC) and the clay content of the different size fractions were determined as well as the specific surface area (SSA_mineral) and the sample pore volume after thermal oxidation (OC‐free). The TOC of the different soil‐aggregate fractions was linearly related to SSA_mineral. Clay‐associated OC and nonassociated OC fractions of the different soil samples were quantified using two methods based on the OC surface loading at the clay fraction. The application of organic fertilizer increased the amount of nonassociated OC but hardly affected the concentration of clay‐associated OC. This finding agrees with previous studies on C dynamics in soils and indicates a finite capacity of soil materials to sequester OC. Even without any addition of organic fertilizer, the mineral phase of the analyzed soil material appears to be C‐saturated.