Understanding tropical forest succession is critical for the development of tropical forest conservation strategies worldwide, given that tropical secondary forests can be considered the forests of ...the future. Tropical dry forests (TDF) are among the most threatened tropical ecosystems, there are more secondary forests and forest restoration efforts that require a better understanding of successional processes. The main goal of this synthesis for this special issue on the ecology and management of tropical dry forests in the Americas is to present a summarized review of the current knowledge of the ecology and management implications associated to TDF succession. We explore specific issues associated to tropical dry forest succession with emphasis on the use of chronosequences, plant diversity and composition, plant phenology and remote sensing, pollination, and animal–plant interactions; all under the integrating umbrella of ecosystem succession. We also emphasize the need to conduct socio-ecological research to understand changes in land-use history and its effects on succession and forest regeneration of TDF. We close this paper with some thoughts and ideas associated with the strong need for an integrating dimension not considered until today: the role of cyberinfrastructure and eco-informatics as a tool to support sound conservation, management and understanding of TDF in the Americas.
We discuss the state of the art and innovative micro- and nanoscale technologies that are finding niches and opening up new opportunities in medicine, particularly in diagnostic and therapeutic ...applications. We take the design of point-of-care applications and the capture of circulating tumor cells as illustrative examples of the integration of micro- and nanotechnologies into solutions of diagnostic challenges. We describe several novel nanotechnologies that enable imaging cellular structures and molecular events. In therapeutics, we describe the utilization of micro- and nanotechnologies in applications including drug delivery, tissue engineering, and pharmaceutical development/testing. In addition, we discuss relevant challenges that micro- and nanotechnologies face in achieving cost-effective and widespread clinical implementation as well as forecasted applications of micro- and nanotechnologies in medicine.
Three‐dimensional food printing (3DFP) uses additive manufacturing concepts to fabricate customized designed products with food ingredients in powder, liquid, dough, or paste presentations. In some ...cases, it uses additives, such as hydrocolloids, starch, enzymes, and antibrowning agents. Chocolate, cheese, sugar, and starch‐based materials are among the most used ingredients for 3DFP, and there is a broad and growing interest in meat‐, fruit‐, vegetable‐, insect‐, and seaweed‐based alternative raw materials. Here, we reviewed the most recent published information related to 3DFP for novel uses, including personalized nutrition and health‐oriented applications, such as the use of 3D‐printed food as a drug vehicle, and four‐dimensional food printing (4DFP). We also reviewed the use of this technology in aesthetic food improvement, which is the most popular use of 3DFP recently. Finally, we provided a prospective and perspective view of this technology. We also reflected on its multidisciplinary character and identified aspects in which social and regulatory affairs must be addressed to fulfill the promises of 3DFP in human health improvement.
Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this ...context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for not only bat biodiversity conservation but also for the conservation of the key ecological processes they provide.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Microalgae-based CO₂ capture from flue gas is an attractive mitigation strategy in the cement industry. However, NO ₓ and SO ₓ components might be harmful to microalgae. We performed toxicity assays, ...under 2 % (v/v) CO₂ and using nitrite, sulfite, or bisulfite salts, on an environmental isolate, identified as Desmodesmus abundans (The University of Texas at Austin (UTEX), no. 2976) and Scenedesmus sp. UTEX1589. Nitrite and sulfite did not inhibit growth at the tested concentrations (0–1,067 ppm (w/v) NO₂ ⁻ and 0–254 ppm (w/v) SO₃ ²⁻); however, bisulfite was toxic above 39 ppm. Non-toxic concentrations of both sulfur-based compounds stimulated growth, but significantly higher growth rates were only observed for HSO₃ ⁻. Within a narrower range, NO ₓ and SO ₓ served as a sole nutrient source. Overall, biomass production and growth rates of the environmental isolate were greater. A novel strategy to buffer high concentrations of HSO₃ ⁻ (200 ppm) was developed by adding cement kiln dust (CKD), a byproduct and flue gas component. The results suggest that CKD also provided other beneficial growth components and that sulfur optimization of the culture medium significantly increased carbon assimilation, particularly in D. abundans. In additional simulations of typical flue gas conditions in a modern cement plant (320, 40, and 40 ppm (w/v) of NO₂ ⁻, SO₃ ²⁻, and HSO₃ ⁻, respectively, and 25 % (v/v) CO₂), along with the incorporation of 300 ppm CDK, growth of D. abundans was supported. Although further studies are needed, direct utilization of flue gas might be possible with the environmental isolate, where NO ₓ , SO ₓ , and CKD are all beneficial components of the mitigation system.
Multiple human tissues exhibit fibrous nature. Therefore, the fabrication of hydrogel filaments for tissue engineering is a trending topic. Current tissue models are made of materials that often ...require further enhancement for appropriate cell attachment, proliferation and differentiation. Here we present a simple strategy, based on the use surface chaotic flows amenable of mathematical modeling, to fabricate continuous, long and thin filaments of gelatin methacryloyl (GelMA). The fabrication of these filaments is achieved by chaotic advection in a finely controlled and miniaturized version of the journal bearing (JB) system. A drop of GelMA pregel was injected on a higher-density viscous fluid (glycerin) and a chaotic flow is applied through an iterative process. The hydrogel drop is exponentially deformed and elongated to generate a fiber, which was then polymerized under UV-light exposure. Computational fluid dynamic (CFD) simulations are conducted to determine the characteristics of the flow and design the experimental conditions for fabrication of the fibers. GelMA fibers were effectively used as scaffolds for C2C12 myoblast cells. Experimental results demonstrate an accurate accordance with CFD simulations for the predicted length of the fibers. Plant-based viral nanoparticles (i.e., Turnip mosaic virus; TuMV) were then integrated to the hydrogel fibers as a secondary nano-scaffold for cells for enhanced muscle tissue engineering. The addition of TuMV significantly increased the metabolic activity of the cell-seeded fibers (p*<0.05), strengthened cell attachment throughout the first 28 days, improved cell alignment, and promoted the generation of structures that resemble natural mammal muscle tissues. Chaotic 2D-printing is proven to be a viable method for the fabrication of hydrogel fibers. The combined use of thin and long GelMA hydrogel fibers enhanced with flexuous virions offers a promising alternative for scaffolding of muscle cells and show potential to be used as cost-effective models for muscle tissue engineering purposes.
(OFI) contains health-promoting compounds like flavonoids, being the isorhamnetin glycosides the most abundant. We evaluated the effect of OFI extracts with different isorhamnetin glycosides against ...two different human colon cancer cells (HT-29 and Caco2). The extracts were obtained by alkaline hydrolysis with NaOH at 40 °C during 15, 30 or 60 min. Tri and diglycosides were the most abundant isorhamnetin glycosides, therefore these compounds were isolated to compare their cytotoxic effect with the obtained from the extracts. The OFI extracts and purified isorhamnetin glycosides were more cytotoxic against HT-29 cells than Caco2 cells. OFI-30 exhibited the lowest IC₅₀value against HT-29 (4.9 ± 0.5 μg/mL) and against Caco2 (8.2 ± 0.3 μg/mL). Isorhamnetin diglycosides IG5 and IG6 were more cytotoxic than pure isorhamnetin aglycone or triglycosides when they were tested in HT-29 cells. Bioluminescent analysis revealed increased activity of caspase 3/7 in OFI extracts-treated cells, particularly for the extract with the highest concentration of isorhamnetin triglycosides. Flow cytometry analysis confirmed that OFI extract and isorhamnetin glycosides induced a higher percentage of apoptosis in HT-29 than in Caco2, while isorhamnetin was more apoptotic in Caco2. This research demonstrated that glycosilation affected antiproliferative effect of pure isorhamnetin glycosides or when they are mixed with other phytochemicals in an extract obtained from OFI.
Circulating tumor cells (CTCs) have the potential of becoming the gold standard marker for cancer diagnosis, prognosis and monitoring. However, current methods for its isolation and characterization ...suffer from equipment variability and human operator error that hinder its widespread use. Here we report the design and construction of a fully automated high-throughput fluorescence microscope that enables the imaging and classification of cancer cells that were labeled by immunostaining procedures. An excellent agreement between our machine vision-based approach and a state-of-the-art microscopy equipment was achieved. Our integral approach provides a path for operator-free and robust analysis of cancer cells as a standard clinical practice.
PDF
