1,148 research outputs found

    Ant Community in Neotropical Agrosystems: A Four-Year Study in Conventional and No-Tillage Systems

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    Studies comparing agricultural practices that maintain a better quality and a healthy soil fauna consider the no-tillage farming as the most effective practice when compared to other planting techniques. In order to evaluate the influence of the no-tillage and conventional tillage methods (with and without manipulation of the soil before planting, respectively) on ant communities, we monitored two areas with these two types of practice (conventional and no-tillage) over the period of four years. We collected ants once per month along 10 transects randomly distributed using three pitfall traps in each area. In addition, we collected the dead plant biomass present at each point sampled as a parameter for measuring the environmental complexity of the areas. In total, we captured 27,480 individuals belonging to 26 species in the no-tillage area and 24,570 individuals belonging to 24 species in the conventional tillage area. The generalised linear model analysis showed that the no-tillage system had the highest abundance of individuals, as well as richness and diversity of species, during most of the study period, as compared to conventional tillage areas. We also found a significant positive correlation between species richness and dead plant biomass. Thus, it is possible to infer that the no-tillage area is a more complex environment with a greater diversity of ants and, therefore, a more sustainable agrosystem as compared to conventional tillage areas

    The Influence of Fire and Deforestation on the Floral Symmetry and Fitness of Adenocalymma nodosun (Bignoniaceae)

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    Burnings and deforestation are severe disturbances to plants and may represent a stressful situation for plant growth, and they can also affect plant-pollinator interactions and the reproductive success of plants. In this study, we verified the variation in floral symmetry of Adenocalymma nodosum (Bignoniacea) in two areas, one post-fire and other after deforestation. We also verified the effects on plant-pollinator interactions and fruit set production. Results showed that A. nodosum flowers were more asymmetric in mowing areas than in fire areas. Asymmetrical flowers presented low nectar concentration and bee visitation rates. Although mowed environments produce fewer fruits and seeds than areas affected by fire, the change was not significant. Soil from the burnt area showed higher nutrient and organic matter concentration and less aluminum than that of mowed areas. Our results showed that A. nodosum flowers in the deforestation area are more asymmetric than those in the post-fire area. This result suggest that Cerrado plants may be less adapted to deforestation than to fire, since they have been facing fire events for thousand years in this biome. We suggest that the effects of environmental stress on the development and fitness of plants may provide an important breakthrough to the understanding of insect-plant interactions in Cerrado savanna, where burnings and deforestation are frequent anthropogenic effects

    Attachment, Growth, and Detachment of Human Mesenchymal Stem Cells in a Chemically Defined Medium

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    Citation: Denise Salzig, Jasmin Leber, Katharina Merkewitz, Michaela C. Lange, Natascha Köster, and Peter Czermak, “Attachment, Growth, and Detachment of Human Mesenchymal Stem Cells in a Chemically Defined Medium,” Stem Cells International, vol. 2016, Article ID 5246584, 10 pages, 2016. doi:10.1155/2016/5246584The manufacture of human mesenchymal stem cells (hMSCs) for clinical applications requires an appropriate growth surface and an optimized, preferably chemically defined medium (CDM) for expansion. We investigated a new protein/peptide-free CDM that supports the adhesion, growth, and detachment of an immortalized hMSC line (hMSC-TERT) as well as primary cells derived from bone marrow (bm-hMSCs) and adipose tissue (ad-hMSCs). We observed the rapid attachment and spreading of hMSC-TERT cells and ad-hMSCs in CDM concomitant with the expression of integrin and actin fibers. Cell spreading was promoted by coating the growth surface with collagen type IV and fibronectin. The growth of hMSC-TERT cells was similar in CDM and serum-containing medium whereas the lag phase of bm-hMSCs was prolonged in CDM. FGF-2 or surface coating with collagen type IV promoted the growth of bm-hMSCs, but laminin had no effect. All three cell types retained their trilineage differentiation capability in CDM and were detached by several enzymes (but not collagenase in the case of hMSC-TERT cells). The medium and coating did not affect detachment efficiency but influenced cell survival after detachment. CDM combined with cell-specific surface coatings and/or FGF-2 supplements is therefore as effective as serum-containing medium for the manufacture of different hMSC types

    Aquaculture in Brazil and worldwide: overview and perspectives

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    Aquaculture is the cultivation of aquatic organisms through a controlled cultivation process. Currently, half the fish consumed by the world population is produced by aquaculture activity. This review, and informed data, trends, and the general panorama of aquaculture in Brazil and worldwide, as well as the scenario of the tilapia (Oreochromis niloticus) production, in order to provide specific directions for future investments and researches. Globally, fish aquaculture productivity is approximately 110 million tons in 2016, with China being the country with the highest productivity (49 million tons). Brazil occupies the 13th place with about 700 thousand tons of aquaculture fish, where tilapia is one of the most cultivated. Furthermore, the ration production for aquaculture is one of the fastest-growing sectors in the country (930 thousand tons of ration represents 1.33% concerning the total feed produced to cultivation of the animals – data of 2016), with emphasis on the biofloc system, which represents a productive method with better cost-benefit and low environmental impact. In general, aquaculture trends are the real progress of this activity, but so that social, economic, and environmental aspects are interconnected and progressing concomitantly

    Flower-visiting social wasps and plants interaction: Network pattern and environmental complexity

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    Network analysis as a tool for ecological interactions studies has been widely used since last decade. However, there are few studies on the factors that shape network patterns in communities. In this sense, we compared the topological properties of the interaction network between flower-visiting social wasps and plants in two distinct phytophysiognomies in a Brazilian savanna (Riparian Forest and Rocky Grassland). Results showed that the landscapes differed in species richness and composition, and also the interaction networks between wasps and plants had different patterns. The network was more complex in the Riparian Forest, with a larger number of species and individuals and a greater amount of connections between them. The network specialization degree was more generalist in the Riparian Forest than in the Rocky Grassland. This result was corroborated by means of the nestedness index. In both networks was found asymmetry, with a large number of wasps per plant species. In general aspects, most wasps had low niche amplitude, visiting from one to three plant species. Our results suggest that differences in structural complexity of the environment directly influence the structure of the interaction network between flower-visiting social wasps and plants

    The Ursinus Weekly, November 11, 1977

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    Task force in gear • The Medical Credentials Committee • Financial aid simplified • 16 selected for Who\u27s who • After graduation • Ursinus news in brief: Ruby sellout; New Library service • Comment: Take a risk • Letters to the editor • Movie attack: Exorcist two; You light up my life; The Island of Dr. Moreau • Comment on the arts • Art and loneliness III • On killing blank space • Andy Campbell • Women\u27s volleyball • Hockey wins • Bears edge Widener • 3 & 4 score morehttps://digitalcommons.ursinus.edu/weekly/1076/thumbnail.jp

    Agile development of a virtual reality cognitive assessment

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    In recent years user-centered design, participatory design and agile development have seen much popularity in the field of software development. More specifically, applying these methods to user groups with cognitive and motor disabilities has been the topic of numerous publications. However, neuropsychological assessment and training require special consideration to include therapists and brain-injured patients into the development cycle. Application goals, development tools and communication between all stakeholders are interdependent and outlined in a framework that promotes elements of agile development. The framework is introduced by example of a virtual reality cognitive assessment for patients with traumatic brain injuries. The assessment has seen a total of 20 iterations over the course of nine months including changes in task content, task difficulty, user interaction and data collection. The framework and development of the cognitive assessment are discussed.Peer Reviewe
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