The budget of nitrogen in the grow‐out of the Amazon river prawn (Macrobrachium amazonicum Heller) and tambaqui (Colossoma macropomum Cuvier) farmed in monoculture and in integrated multitrophic aquaculture systems

This work determined the nitrogen inputs, outputs and accumulation in compartments of stagnant earthen ponds for the monoculture and integrated multi‐trophic aquaculture (IMTA) of the Amazon river prawn (Macrobrachium amazonicum) and tambaqui (Colossoma macropomum), using recycled hypereutrophic water. A completely randomized experiment was designed with four treatments and three replications: PM–monoculture with 30 prawns/m², FM ‐ monoculture with 3 fish/m², IMTA ‐ polyculture with 30 prawns/m² and 30 fish/m² free, POLY‐CAGE ‐ polyculture with 30 prawns/m² free and 40 fish/m³ in net‐cages. Animals, rain, water, feed, soil, gas, accumulated sludge, and suspended sediments were collected throughout the experiment to determine their nitrogen contents and to calculate the nitrogen budget. Results showed that much of the nitrogen available escapes to atmosphere as N₂ (~40%–56%) after denitrification or accumulated within bottom sludge (~14%–42%). The remaining nitrogen was converted in animal biomass (~5%–21%) or was discharged to receiving waterbodies in the outlet water (~11%–13%). Feed management appeared to influence the major biological processes in the aquatic nitrogen cycle, such as photosynthesis and denitrification. The fish‐prawn IMTA systems converted approximately 53%–75% of feed nitrogen into harvestable products, which is more efficient than the 19%–46% of feed nitrogen converted in the monocultures. However, a large amount of nitrogen is accumulated in the pond bottom in all systems. An increased prawn density or the addition of a mud‐feeder species to the culture may enhance the incorporation of this material in harvested biomass, improving the efficiency of the systems.     

Detection of Bemisia tabaci Mediterranean cryptic species on soybean in São Paulo and Paraná States (Brazil) and interaction of cowpea mild mottle virus with whiteflies

Since the detection of Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) species in Brazil in the early 1990s, this whitefly has been the predominant species and the main viral vector in the country. In this work, whiteflies were collected from commercial soybean fields near and far from greenhouses where Mediterranean (MED) species had previously been detected infesting vegetable crops. Results indicated that MEAM1 was the predominant whitefly species in soybean in most sampling sites, while MED was found colonizing soybean plants in open field conditions alone and/or with MEAM1 in several places. Among the tested insects, MED species was mostly detected harbouring the facultative endosymbiont Hamiltonella. We also detected cowpea mild mottle virus (CPMMV) infecting soybean plants. Transmission assays demonstrated that MED species was more efficient transmitting CPMMV from beans to beans and from soybean to soybean plants than MEAM1, while MEAM1 was more efficient in transmitting the virus from soybean to bean than MED. Performance assays indicated that adult emergence of both species on CPMMV-infected soybean plants was higher when compared with the emergence on healthy plants. Moreover, nonviruliferous MED and MEAM1 adults preferred to settle more often on healthy plants, while viruliferous adults settled more often on CPMMV-infected soybean plants. As MED has already been found in soybean open fields in São Paulo and Paraná States, Brazil, and it is a good vector of CPMMV, we anticipate problems related to whitefly management and to increase in the incidence of the virus in soybean.     

Managing “Marandu” palisadegrass and calopo pastures based on light interception

Light interception (LI) in grazing management has been an efficient tool to harvest forage under similar growth stage conditions. The objective was to define the best grazing management strategies (GMSs) based on LI in marandu palisadegrass (Brachiaria brizantha [Hochst. ex A. Rich.] R. Webster cv. Marandu) and calopo (Calopogonium mucunoides Desv. cv. Comum) mixed pastures. Three GMSs were evaluated in a randomized block design: rest period interrupted at 90% (90LI), 95% (95LI) and 100% (100LI) of LI. The experimental period was divided into four periods: rainy seasons and transitions (between rainy and dry seasons). Post-grazing stubble height target was 15 cm. Canopy height, forage mass, leaf area index (LAI), morphogenic variables and tiller demographic pattern were evaluated. Pre- and post-grazing canopy height increased at 100LI. Pre-grazing forage mass decreased over time in all GMSs. The relationship among canopy height, forage mass and LI was not constant throughout the experiment. Post-grazing forage mass was greatest at 90LI. There was an increase in legume mass throughout the experiment; however, the proportion of legume in pre-grazing forage mass was no more than 6.6% for all GMSs. Number of calopo branches per plant and LAI increased throughout the experiment while the number of plants decreased. The 95LI provided the best conditions for calopo development; however, the LI as a tool to determine the entry of animals in mixed pastures of marandu palisadegrass and calopo should be carefully applied, considering the seasonal variations in canopy botanical and structural composition under similar LI.     

Pomegranate Juice and Peel Extracts are Able to Inhibit Proliferation,Migration and Colony Formation of Prostate Cancer Cell Lines and Modulate the Akt/mTOR/S6K Signaling Pathway

Plant Foods for Human Nutrition - Pomegranate (Punica granatum) is known to contain polyphenols with many potential health benefits, including anti-tumoral, anti-inflammatory, and anti-microbial...     

Determination of Phenolic Compounds in Three Edible Ripening Stages of Yellow Guava (Psidium cattleianum Sabine) after Acidic Hydrolysis by LC-MS/MS

Plant Foods for Human Nutrition - Yellow guava (Psidium cattleianum Sabine) has received considerable attention in the last years because of their high content in bioactive compounds with potential...     

Effects of duration and intensity of aluminum stress on growth parameters in four rice genotypes differing in aluminum sensitivity

The effects of aluminum (Al) stresses of varying intensities and durations on growth parameters were investigated in four Oryza sativa L. genotypes (two Al sensitive, two Al resistant). Our results support the current opinion that the use of only one parameter cannot easily account for differences in Al resistance, since Al concentration or stress duration can affect plant responses in opposite directions. For short stress duration (40 days) at Al 500 μM, weight parameters appear to be more discerning than length parameters. Necrosis evaluation is a more reliable criterion for plants maintained for a long time (80 days) in the presence of high Al concentrations (Al 1000 or 1500 μM).     

Endogenous Progesterone Concentrations Affect Progesterone Release from Intravaginal Devices Used for Oestrous Synchronization in Cattle

Intravaginal progesterone‐releasing devices are largely used both as contraceptives in humans and as a component of oestrous synchronization protocols in cattle. To reduce costs in large‐scale timed artificial insemination, the reuse of these releasing devices is common. Passive hormone diffusion, however, depends on the concentration gradient, which could affect the amount of residual progesterone present in these devices after a first use. To evaluate the effect of the presence of a corpus luteum in the release of progesterone from intravaginal devices, three synchronization protocols were designed to simulate the effects of inserting the device in the early dioestrus, late dioestrus or anoestrus. Holstein‐Zebu cross‐bred heifers were randomly allocated into one of these three treatments, and a series of blood samples was taken to evaluate the plasma progesterone concentrations. After 8 days, the intravaginal devices were removed and underwent a previously validated alcoholic extraction technique to measure the residual progesterone. Non‐used devices were used as controls. As expected, the simultaneous presence of the intravaginal device and a corpus luteum resulted in increased plasma progesterone concentrations. Conversely, the amount of residual progesterone in the devices after use was inversely proportional to the plasma progesterone concentration. These results demonstrate that the release rate of progesterone from intravaginal devices is affected by the endogenous concentration of this hormone; consequently, the strategy for reuse should account for the category and expected luteal cyclic activity of the animals undergoing synchronization protocols.     

Canine visceral leishmaniasis and Rhipicephalus sanguineus: evaluation and comparison of classical techniques

Veterinary Research Communications - The aim of this study was evaluating the association and correlation between the diagnostics tests used for Leishmania spp. detection in dogs and ticks. We...     

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...