The interspecific variation of plant traits in brassicas engenders stronger aphid suppression than the intraspecific variation of single plant trait

Journal of Pest Science - Increasing either inter- or intraspecific plant diversity has shown the potential to engender bottom-up and top-down effects upon herbivorous pests. Nonetheless, because...     

Agroforestry systems recover tree carbon stock faster than natural succession in Eastern Amazon,Brazil

Agroforestry Systems - The potential of agroforestry systems (AFS) for atmospheric carbon sequestration in degraded tropical lands is of key interest for climate change and rural development...     

New Engineering Contract and Traditional Engineering Contracts

This paper analyzes the key principles on which the international traditional contracts and new engineering contract have been drafted as well as the contractual relations among the parties involved in the execution of the project. This paper concluded that the new engineering contract prepared by the Institute of Civil Engineers has shown its unique features in the principles and new management techniques and is able to stimulate good project management.     

Real time computer stress monitoring of piglets using vocalization analysis

The analysis of animal vocalization allows the interpretation of stress pattern in a non-invasive way, and it may be used to assess welfare as well as health status and social adaptation. This paper presents the development of software to monitor and analyze distinct sounds emitted by piglets correlating the noise response with levels of stress for assessing welfare. The software was developed using Delphi5. Through the component UwaveIn the sound was recorded with an electronic microphone and set to a PC hardware that registered the signal of amplitude noise intensity, expressed in decibel (dB), converting them into bytes. Fourier Transform was used to describe the sound spectrum and transform it into frequency and intensity. Validation of the software was done in a commercial swine farm using piglets from sows’ nursery. Five examples of vocalization were studied related to distinct levels of stress (fear and alertness) due to regular management procedures. The real time monitoring allowed the detection of piglet stress exposure through the surface point polynomial adjustment. The acoustic signal recorded in the software could be partitioned allowing an evaluation of the sonograph through time.     

Genotypic characterization of Toxoplasma gondii in sheep from Brazilian slaughterhouses: new atypical genotypes and the clonal type II strain identified

Toxoplasma gondii strains are genetically diverse in South America. To date, hundreds of T. gondii isolates from different animal hosts were genotyped in Brazil, most of them are different from those identified around the world. This study aimed to determine T. gondii infection rate in sheep from Brazilian slaughterhouses, as well as the genotype of these isolates. T. gondii antibodies were detected in 66/602 (10.96%) serum samples through modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT). MAT-HS and IFAT-IgG presented high concordance (0.95) and strong correlation (r=0.79). T. gondii DNA was detected in tissue samples of 33% (22/66) serum positive sheep by PCR of the 529 bp repetitive element. In the bioassay in mice, T. gondii were detected in mice brain or muscle tissues in 30% (20/66) of serum positive sheep. Positive samples were typed through Restriction Fragment Length Polymorphism (RFLP-PCR) using 11 markers: SAG1, SAG2 (5'-3'SAG2 and alt.SAG2), SAG3, BTUB, GRA6, L358, c22-8, c29-6, PK1, Apico and CS3. Of 22 samples, 13 were positive and 9 genotypes were identified. Four of these 9 genotypes are unique. Nine samples had negative results in RFLP-PCR typing, which may be due to low DNA concentration. Six isolates were virulent killing mice between 12 and 25 days postinfection. Two non-virulent isolates belonged to clonal type II genotype, which were not observed in Brazil previously. These findings confirm the high diversity and high frequency of virulent genotypes among Brazilian animals. This study also proved the presence of type II T. gondii in Brazil.     

Amazon forests green-up during 2005 drought

Coupled climate-carbon cycle models suggest that Amazon forests are vulnerable to both long- and short-term droughts, but satellite observations showed a large-scale photosynthetic green-up in intact evergreen forests of the Amazon in response to a short, intense drought in 2005. These findings suggest that Amazon forests, although threatened by human-caused deforestation and fire and possibly by more severe long-term droughts, may be more resilient to climate changes than ecosystem models assume.     

Estimation and evaluation of dynamic properties as indicators of changes on soil structure in sugarcane fields of Sao Paulo State – Brazil

The indiscriminate management and use of soils without moisture control has changed the structure of it due to the increment of the traffic by agricultural machines through the years, causing in consequence, a soil compaction and yield reduction in the areas of intensive traffic. The purpose of this work was to estimate and to evaluate the performance of preconsolidation pressure of the soil and shear stress as indicators of changes on soil structure in fields cropped with sugarcane, as well as the impact of management processes in an Eutrorthox soil structure located in Sao Paulo State. The experimental field was located in Piracicaba's rural area (Sao Paulo State, Brazil) and has been cropped with sugarcane, in the second harvest cycle. The soil was classified by EMBRAPA [EMBRAPA, 1999. Centro Nacional de Pesquisa de Solos. Sistema Brasileiro de Classificação de Solos, Embrapa, Brasília, 412 pp.] as an Eutrorthox. Undisturbed samples were collected and georeferenced in a grid of 60 m × 60 m from two depths: 0–0.10 m (superficial layer – SL) and in the layer of greatest mechanical resistance (LGMR), previously identified by cone index (CI). The investigated variables were pressure preconsolidation (σ_p), apparent cohesion (c) and internal friction angle (). The conclusions from the results were that the SLSC was predicted satisfactorily from σ_p as a function of soil moisture; thus, decisions about machinery size and loading (contact pressures) can be taken. Apparent cohesion (c), internal friction angle () and the Coulomb equation were significantly altered by traffic intensity. The σ_p, c and maps were shown to be important tools to localize and visualize soil compaction and mechanical resistance zones. They constitute a valuable resource to evaluate the traffic impact in areas cropped with sugarcane in State of Sao Paulo, Brazil.