Phylogenetic biome conservatism on a global scale.

Science.gov (United States)

Crisp, Michael D; Arroyo, Mary T K; Cook, Lyn G; Gandolfo, Maria A; Jordan, Gregory J; McGlone, Matt S; Weston, Peter H; Westoby, Mark; Wilf, Peter; Linder, H Peter

2009-04-09

How and why organisms are distributed as they are has long intrigued evolutionary biologists. The tendency for species to retain their ancestral ecology has been demonstrated in distributions on local and regional scales, but the extent of ecological conservatism over tens of millions of years and across continents has not been assessed. Here we show that biome stasis at speciation has outweighed biome shifts by a ratio of more than 25:1, by inferring ancestral biomes for an ecologically diverse sample of more than 11,000 plant species from around the Southern Hemisphere. Stasis was also prevalent in transocean colonizations. Availability of a suitable biome could have substantially influenced which lineages establish on more than one landmass, in addition to the influence of the rarity of the dispersal events themselves. Conversely, the taxonomic composition of biomes has probably been strongly influenced by the rarity of species' transitions between biomes. This study has implications for the future because if clades have inherently limited capacity to shift biomes, then their evolutionary potential could be strongly compromised by biome contraction as climate changes.

Dura mater mitral and tricuspid bioprostheses: 30 years of follow-up Bioprótese de dura mater mitral e tricúspide: 30 anos de acompanhamento

Directory of Open Access Journals (Sweden)

Luiz Boro Puig

2003-01-01

Full Text Available PURPOSE: The dura mater bioprosthesis was developed in the Department of Cardiopneumology of the Hospital das Clínicas of the University of São Paulo Medical School in 1971. Here, we present the clinical results of the dura mater bioprosthesis over 30 years of follow-up. METHODS: We studied 70 consecutive patients who underwent mitral or tricuspid valve replacement with a dura mater bioprosthesis between January 1971 and August 1972. RESULTS: The early mortality was 10% (7 patients. The follow-up was 87% complete (9 patients were lost to follow-up. Two patients were alive and asymptomatic 30 years after valve replacement; 33 patients underwent reoperations due to valve dysfunction, and 19 died during the follow-up period. At 30 years, the actuarial survival was 49.2 ± 8.6%; freedom from rupture, 27.0 ± 10.2%; freedom from calcification, 78.8 ± 8.6%; and freedom from reoperation, 18.8 ± 7.5%. CONCLUSIONS: The dura mater bioprosthesis played an important role in the treatment of patients with mitral and tricuspid valve disease. The low rate of thromboembolism and the long period of follow-up without evidence of valve dysfunction, which occurred for several of our patients, are important characteristics of these bioprosthesis.A bioprótese de dura-mater foi desenvolvida no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo em 1971. Este trabalho apresenta os resultados clínicos com 30 anos de seguimento. MÉTODOS: Foram estudados 70 pacientes consecutivos com bioprótese mitral ou tricúspide, operados de janeiro de 1971 a agosto de 1972. RESULTADOS: A mortalidade imediata foi 10% (7 pacientes. Dois pacientes evoluem bem com a bioprótese de dura-máter, 9 não tem seguimento atualizado, 33 apresentaram disfunção da bioprotese e foram reoperados e 19 faleceram durante a evolução tardia. A curva atuarial de sobrevida foi de 49,2 ± 8,6%, livre de rotura, 27,0 ± 10,2%, livre de calcificação, 78,8 ± 8,6% e

Autoantibody response against NALP5/MATER in primary ovarian insufficiency and in autoimmune Addison's disease.

Science.gov (United States)

Brozzetti, Annalisa; Alimohammadi, Mohammad; Morelli, Silvia; Minarelli, Viviana; Hallgren, Åsa; Giordano, Roberta; De Bellis, Annamaria; Perniola, Roberto; Kämpe, Olle; Falorni, Alberto

2015-05-01

NACHT leucine-rich-repeat protein 5 (NALP5)/maternal antigen that embryo requires (MATER) is an autoantigen in hypoparathyroidism associated with autoimmune polyendocrine syndrome type 1 (APS1) but is also expressed in the ovary. Mater is an autoantigen in experimental autoimmune oophoritis. The objectives of the study were to determine the frequency of NALP5/MATER autoantibodies (NALP5/MATER-Ab) in women with premature ovarian insufficiency (POI) and in patients with autoimmune Addison's disease (AAD) and to evaluate whether inhibin chains are a target for autoantibodies in POI. Autoantibodies against NALP5/MATER and inhibin chains-α and -βA were determined by radiobinding assays in 172 patients with AAD without clinical signs of gonadal insufficiency, 41 women with both AAD and autoimmune POI [steroidogenic cell autoimmune POI (SCA-POI)], 119 women with idiopathic POI, 19 patients with APS1, and 211 healthy control subjects. NALP5/MATER-Ab were detected in 11 of 19 (58%) sera from APS1 patients, 12 of 172 (7%) AAD sera, 5 of 41 (12%) SCA-POI sera, 0 of 119 idiopathic POI sera and 1 of 211 healthy control sera (P < .001). None of 160 POI sera, including 41 sera from women with SCA-POI and 119 women with idiopathic POI, and none of 211 healthy control sera were positive for inhibin chain-α/βA autoantibodies. NALP5/MATER-Ab are associated with hypoparathyroidism in APS1 but are present also in patients with AAD and in women with SCA-POI without hypoparathyroidism. Inhibin chains do not appear to be likely candidate targets of autoantibodies in human POI.

Biomes.

Science.gov (United States)

Web Feet K-8, 2001

2001-01-01

This annotated subject guide to Web sites and additional resources focuses on biomes. Specifies age levels for resources that include Web sites, CD-ROMs and software, videos, books, audios, and magazines; includes professional resources; and presents a relevant class activity. (LRW)

On coupling global biome models with climate models

International Nuclear Information System (INIS)

Claussen, M.

1994-01-01

The BIOME model of Prentice et al. (1992), which predicts global vegetation patterns in equilibrium with climate, is coupled with the ECHAM climate model of the Max-Planck-Institut fuer Meteorologie, Hamburg. It is found that incorporation of the BIOME model into ECHAM, regardless at which frequency, does not enhance the simulated climate variability, expressed in terms of differences between global vegetation patterns. Strongest changes are seen only between the initial biome distribution and the biome distribution computed after the first simulation period, provided that the climate-biome model is started from a biome distribution that resembles the present-day distribution. After the first simulation period, there is no significant shrinking, expanding, or shifting of biomes. Likewise, no trend is seen in global averages of land-surface parameters and climate variables. (orig.)

Viscoelastic finite-element analysis of human skull - dura mater ...

African Journals Online (AJOL)

SERVER

2008-03-18

Mar 18, 2008 ... The elastic-viscous mechanical characteristics must be used for the skull. The viscous strains .... different actions for fresh human dura mater (L0 = 23 mm, θ = 370). f. Creep compliance .... 3180±300. 4026±372. *. 1. 0. E. E.

POMEN DOJENJA ZA OTROKA IN MATER

OpenAIRE

Apat, Alja

2014-01-01

Dojenje je naravni način hranjenja otroka v prvih mesecih njegovega življenja. Omogoča optimalno telesno in duševno rast ter razvoj otroka. Materino mleko vsebuje vsa življenjsko pomembna hranila v pravilnem ravnovesju. Dojenje ima mnoge prednosti, tako za mater, ki doji, kakor za njenega otroka. Pomembno vlogo pri dojenju imajo tudi medicinske sestre v porodnišnici in patronažne medicinske sestre. Njihova naloga je tudi zdravstveno-vzgojno delo pri dojenju. Cilj raziskave je bil ugotoviti os...

Description of the Karoo Biome project

CSIR Research Space (South Africa)

Cowling, RM

1986-01-01

Full Text Available The ecological characteristics and ecological problems of the karoo biome are briefly described. A conceptual basis and guidelines for the development of the Karoo Biome Project are outlined by addressing project goals, project structure...

Description of the Grassland Biome Project

CSIR Research Space (South Africa)

Mentis, MT

1982-10-01

Full Text Available The objectives, organization and research programme of the Grassland Biome Project are described against a background of the biome's ecological characteristics and environmental problems. Four principal research topics wil 1 be focused upon: (i...

Nanofiber scaffolds influence organelle structure and function in bone marrow stromal cells.

Science.gov (United States)

Tutak, Wojtek; Jyotsnendu, Giri; Bajcsy, Peter; Simon, Carl G

2017-07-01

Recent work demonstrates that osteoprogenitor cell culture on nanofiber scaffolds can promote differentiation. This response may be driven by changes in cell morphology caused by the three-dimensional (3D) structure of nanofibers. We hypothesized that nanofiber effects on cell behavior may be mediated by changes in organelle structure and function. To test this hypothesis, human bone marrow stromal cells (hBMSCs) were cultured on poly(ε-caprolactone) (PCL) nanofibers scaffolds and on PCL flat spuncoat films. After 1 day-culture, hBMSCs were stained for actin, nucleus, mitochondria, and peroxisomes, and then imaged using 3D confocal microscopy. Imaging revealed that the hBMSC cell body (actin) and peroxisomal volume were reduced during culture on nanofibers. In addition, the nucleus and peroxisomes occupied a larger fraction of cell volume during culture on nanofibers than on films, suggesting enhancement of the nuclear and peroxisomal functional capacity. Organelles adopted morphologies with greater 3D-character on nanofibers, where the Z-Depth (a measure of cell thickness) was increased. Comparisons of organelle positions indicated that the nucleus, mitochondria, and peroxisomes were closer to the cell center (actin) for nanofibers, suggesting that nanofiber culture induced active organelle positioning. The smaller cell volume and more centralized organelle positioning would reduce the energy cost of inter-organelle vesicular transport during culture on nanofibers. Finally, hBMSC bioassay measurements (DNA, peroxidase, bioreductive potential, lactate, and adenosine triphosphate (ATP)) indicated that peroxidase activity may be enhanced during nanofiber culture. These results demonstrate that culture of hBMSCs on nanofibers caused changes in organelle structure and positioning, which may affect organelle functional capacity and transport. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. J Biomed Mater Res Part B: Appl

Recent advancements in electrospinning design for tissue engineering applications: A review.

Science.gov (United States)

Kishan, Alysha P; Cosgriff-Hernandez, Elizabeth M

2017-10-01

Electrospinning, a technique used to fabricate fibrous scaffolds, has gained popularity in recent years as a method to produce tissue engineered grafts with architectural similarities to the extracellular matrix. Beyond its versatility in material selection, electrospinning also provides many tools to tune the fiber morphology and scaffold geometry. Recent efforts have focused on extending the capabilities of electrospinning to produce scaffolds that better recapitulate tissue properties and enhance regeneration. This review highlights these advancements by providing an overview of the processing variables and setups used to modulate scaffold architecture, discussing strategies to improve cellular infiltration and guide cell behavior, and providing a summary of electrospinning applications in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2892-2905, 2017. © 2017 Wiley Periodicals, Inc.

Graphene as multifunctional delivery platform in cancer therapy.

Science.gov (United States)

Nejabat, Mojgan; Charbgoo, Fahimeh; Ramezani, Mohammad

2017-08-01

The biomedical applications of graphene-based nanomaterials including drug and gene delivery have grown rapidly in the past few years. This is due to its high surface area that results in high cargo loading capacity. It is demonstrated that graphene can improve drug efficacy without increasing the dose of the chemotherapeutic agent in cancer treatment. Considering these valuable benefits of graphene, this review focused on the newest advancements in drug and gene delivery systems using graphene and unveiling advantages and disadvantages of different graphene-based materials in introducing an effective cargo delivery system for cancer therapy. Different approaches for reducing cytotoxic impacts of graphene oxide and production of biocompatible delivery platform were also reviewed. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2355-2367, 2017. © 2017 Wiley Periodicals, Inc.

Kynurenine aminotransferase in the supratentorial dura mater of the rat: effect of stimulation of the trigeminal ganglion.

Science.gov (United States)

Knyihár-Csillik, Elizabeth; Chadaide, Zoltán; Okuno, Etsuo; Krisztin-Péva, Beata; Toldi, József; Varga, Csaba; Molnár, Andor; Csillik, Bert; Vécsei, László

2004-04-01

Electrical stimulation of the trigeminal ganglion has been widely used as a model of nociception, characterizing migraine. This treatment is known to evoke release of neuropeptides and neurotransmitters from nerve fibers of the dura mater. On the basis of immunocytochemical investigations, we found that under normal conditions, surface membranes of Schwann cells surrounding nerve fibers in the supratentorial dura mater display kynurenine aminotransferase-immunoreaction (KAT-IR); also KAT-IR are the granules of mast cells and the cytoplasms of macrophages (histiocytes). In consequence of stimulation of the trigeminal ganglion, Schwann cells in the dura mater became conspicuously swollen while their KAT-IR decreased considerably; also KAT-IR of mast cells and macrophages decreased significantly. At the same time, nitric oxide synthase (NOS)-IR of nerve fibers in the dura mater increased, suggesting release of nitric oxide (NO), this is known to be involved in NMDA receptor activation leading to vasodilation followed by neurogenic inflammation. Because kynurenic acid (KYNA) is an antagonist of NMDA receptors, we hypothesize that KYNA and its synthesizing enzyme, KAT, may play a role in the prevention of migraine attacks.

PVDF multifilament yarns grafted with polystyrene induced by γ-irradiation: Influence of the grafting parameters on the mechanical properties

International Nuclear Information System (INIS)

Marmey, P.; Porte, M.C.; Baquey, Ch.

2003-01-01

The development of alternative prosthetic materials for cardiovascular applications has found growing interest due to the failure to date to be able to implement functional patent small diameter vascular grafts (diameter <5 mm). For instance, the successful implantation of small diameter polyester (PET) and expanded polytetrafluoroethylene (PTFEe) vascular grafts has not been achieved in humans. Our strategy is to work with a new multifilament yarns biomaterial, produced from polyvinylidene fluoride (PVDF), which shows suitable mechanical properties, such as a lower tensile modulus than PET and PTFEe. The required biological properties sought for (i.e. low thrombogenicity) could be achieved by 'heparin-like' surface modification treatments in order to modify the thrombogenicity levels of the polymeric materials [Ann. Biomed. Eng. 7 (1979) 429]. A four step method is necessary to achieve this 'heparin-like' surface transformation [J. Biomed. Mater. Res. 52 (2000) 119]. The first step consists in grafting polystyrene onto the PVDF surface by γ irradiation. The purpose of this study was to evaluate the influence of grafting parameters on the mechanical properties: (i) γ-ray irradiation time and (ii) grafting time of styrene monomers, which polymerize and form polystyrene bound to the PVDF surface

Use of a biomimetic strategy to engineer bone.

Science.gov (United States)

Holy, C E; Fialkov, J A; Davies, J E; Shoichet, M S

2003-06-15

Engineering trabecular-like, three-dimensional bone tissue throughout biodegradable polymer scaffolds is a significant challenge. Using a novel processing technique, we have created a biodegradable scaffold with geometry similar to that of trabecular bone. When seeded with bone-marrow cells, new bone tissue, the geometry of which reflected that of the scaffold, was evident throughout the scaffold volume and to a depth of 10 mm. Preseeded scaffolds implanted in non-healing rabbit segmental bone defects allowed new functional bone formation and bony union to be achieved throughout the defects within 8 weeks. This marks the first report of successful three-dimensional bone-tissue engineering repair using autologous marrow cells without the use of supplementary growth factors. We attribute our success to the novel scaffold morphology. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 447-453, 2003

Dynamic vegetation modeling of tropical biomes during Heinrich events

Science.gov (United States)

Handiani, Dian Noor; Paul, André; Dupont, Lydie M.

2010-05-01

Heinrich events are thought to be associated with a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), which in turn would lead to a cooling of the North Atlantic Ocean and a warming of the South Atlantic Ocean (the "bipolar seesaw" hypothesis). The accompanying abrupt climate changes occurred not only in the ocean but also on the continents. Changes were strongest in the Northern Hemisphere but were registered in the tropics as well. Pollen data from Angola and Brazil showed that climate changes during Heinrich events affected vegetation patterns very differently in eastern South America and western Africa. To understand the differential response in the terrestrial tropics, we studied the vegetation changes during Heinrich events by using a dynamic global vegetation model (TRIFFID) as part of the University of Victoria (UVic) Earth System-Climate Model (ESCM). The model results show a bipolar seesaw pattern in temperature and precipitation during a near-collapse of the AMOC. The succession in plant-functional types (PFTs) showed changes from forest to shrubs to desert, including spreading desert in northwest Africa, retreating broadleaf trees in West Africa and northern South America, but advancing broadleaf trees in Brazil. The pattern is explained by a southward shift of the tropical rainbelt resulting in a strong decrease in precipitation over northwest and West Africa as well as in northern South America, but an increase in precipitation in eastern Brazil. To facilitate the comparison between modeled vegetation results with pollen data, we diagnosed the distribution of biomes from the PFT coverage and the simulated model climate. The biome distribution was computed for Heinrich event 1 and the Last Glacial Maximum as well as for pre-industrial conditions. We used a classification of biomes in terms of "mega-biomes", which were defined following a scheme originally proposed by BIOME 6000 (v 4.2). The biome distribution of the Sahel region

Claudia Quinta (Pro Caelio 34 and an altar to Magna Mater

Directory of Open Access Journals (Sweden)

Eleanor Winsor Leach

2010-11-01

Full Text Available Among the items of sculpture from the Capitoline collection now housed in the Museum of the Power Station Montemartini is a marble relief altar of the Claudian Period (E. Simon's dating dedicated to the mater deorum and the navis salvia and depicting the arrival of the goddess Cybele at Rome by ship. The dedicator is one Claudia Syntyche and the sculpture alludes to the legends attached to a much honored woman of the Claudian family whom Cicero, in his oration pro Caelio brought on stage in a cameo appearance to bolster his case against the controversial contemporary woman Clodia Metelli as one of the accusers of his client M. Caelius Rufus. This paper will consider questions raised by the iconography of the altar with reference to the development of Claudia's legend in Roman mythology and subsequently ask who was this Claudia the dedicator and why did she choose Magna Mater for her vow?

Changes in forest productivity across Alaska consistent with biome shift

Science.gov (United States)

Peter S.A. Beck; Glenn P. Juday; Claire Alix; Valerie A. Barber; Stephen E. Winslow; Emily E. Sousa; Patricia Heiser; James D. Herriges; Scott J. Goetz

2011-01-01

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest...

Using an Exploratory Internet Activity & Trivia Game to Teach Students about Biomes

Science.gov (United States)

Richardson, Matthew L.

2009-01-01

Students in life science classes need an introduction to biomes, including an introduction to the concept, key biotic and abiotic features of biomes, and geographic locations of biomes. In this activity, students in seventh- and eighth-grade science classes used a directed exploratory Internet activity to learn about biomes. The author tested…

Matere z motnjami v duševnem razvoju

OpenAIRE

Kolarič, Sandra

2015-01-01

S pregledom tuje literature in že opravljenih raziskav v tujini smo v teoretičnem delu magistrske naloge zajeli značilnosti mater z motnjami v duševnem razvoju, dejavnike, ki vplivajo na uspešnost opravljanja materinske vloge, ter pravice oseb z motnjami v duševnem razvoju do starševstva, v povezavi z zakonodajo na slovenskem. Navedli smo vzroke za omejevanje reprodukcije pri ženskah z motnjami v duševnem razvoju in problematiko odvzema skrbništva materam z motnjami v duševnem razvoju nad otr...

The extent of forest in dryland biomes

Science.gov (United States)

Jean-Francois Bastin; Nora Berrahmouni; Alan Grainger; Danae Maniatis; Danilo Mollicone; Rebecca Moore; Chiara Patriarca; Nicolas Picard; Ben Sparrow; Elena Maria Abraham; Kamel Aloui; Ayhan Atesoglu; Fabio Attore; Caglar Bassullu; Adia Bey; Monica Garzuglia; Luis G. GarcÌa-Montero; Nikee Groot; Greg Guerin; Lars Laestadius; Andrew J. Lowe; Bako Mamane; Giulio Marchi; Paul Patterson; Marcelo Rezende; Stefano Ricci; Ignacio Salcedo; Alfonso Sanchez-Paus Diaz; Fred Stolle; Venera Surappaeva; Rene Castro

2017-01-01

Dryland biomes cover two-fifths of Earth’s land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high...

Addendum: Compliant electrostatic chuck based on hairy microstructure (2013 Smart Mater. Struct. 22 015019) and Electrostatic chuck consisting of polymeric electrostatic inductive fibers for handling of objects with rough surfaces (2013 Smart Mater. Struct. 22 095010)

International Nuclear Information System (INIS)

Saito, Shigeki; Soda, Fumiaki; Sawai, Kenji; Dhelika, Radon; Kikutani, Takeshi; Takarada, Wataru; Takahashi, Kunio

2014-01-01

The recent papers Saito et al 2013 Smart Mater. Struct. 22 015019 and Dhelika et al 2013 Smart Mater. Struct. 22 095010 described studies of an electrostatic chuck that mimics the structure of gecko-like toes. Earlier work published by the authors and other researchers is cited to further illustrate the origin and motivation of the research. (paper)

Importance of ecotone type to landscape dynamics at biome transition zones

Science.gov (United States)

Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsc...

Interaction of ionizing radiation with mater; Oddzialywanie promieniowania jonizujacego z materia

Energy Technology Data Exchange (ETDEWEB)

Pogocki, D [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

1997-10-01

The early radiation effects (e.g. excitation, ionization) have been described and compared for different kind of radiation interacting with mater. The mechanism of energy deposition in connection with radiation dose and their spatial distribution has been shown.The commonly used definitions and units in radiation dosimetry have been also reviewed. 4 refs, 4 figs.

Changes in forest productivity across Alaska consistent with biome shift.

Science.gov (United States)

Beck, Pieter S A; Juday, Glenn P; Alix, Claire; Barber, Valerie A; Winslow, Stephen E; Sousa, Emily E; Heiser, Patricia; Herriges, James D; Goetz, Scott J

2011-04-01

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline. © 2011 Blackwell Publishing Ltd/CNRS.

Diverging responses of tropical Andean biomes under future climate conditions.

Directory of Open Access Journals (Sweden)

Carolina Tovar

Full Text Available Observations and projections for mountain regions show a strong tendency towards upslope displacement of their biomes under future climate conditions. Because of their climatic and topographic heterogeneity, a more complex response is expected for biodiversity hotspots such as tropical mountain regions. This study analyzes potential changes in the distribution of biomes in the Tropical Andes and identifies target areas for conservation. Biome distribution models were developed using logistic regressions. These models were then coupled to an ensemble of 8 global climate models to project future distribution of the Andean biomes and their uncertainties. We analysed projected changes in extent and elevational range and identified regions most prone to change. Our results show a heterogeneous response to climate change. Although the wetter biomes exhibit an upslope displacement of both the upper and the lower boundaries as expected, most dry biomes tend to show downslope expansion. Despite important losses being projected for several biomes, projections suggest that between 74.8% and 83.1% of the current total Tropical Andes will remain stable, depending on the emission scenario and time horizon. Between 3.3% and 7.6% of the study area is projected to change, mostly towards an increase in vertical structure. For the remaining area (13.1%-17.4%, there is no agreement between model projections. These results challenge the common believe that climate change will lead to an upslope displacement of biome boundaries in mountain regions. Instead, our models project diverging responses, including downslope expansion and large areas projected to remain stable. Lastly, a significant part of the area expected to change is already affected by land use changes, which has important implications for management. This, and the inclusion of a comprehensive uncertainty analysis, will help to inform conservation strategies in the Tropical Andes, and to guide similar

Generality of leaf trait relationships: A test across six biomes

Energy Technology Data Exchange (ETDEWEB)

Reich, P.B. [Univ. of Minnesota, Saint Paul, MN (United States). Dept. of Forest Resources; Ellsworth, D.S. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Walters, M.B. [Michigan State Univ., East Lansing, MI (United States). Dept. of Forestry; Vose, J.M. [Forest Service, Otto, NC (United States). Coweeta Hydrological Lab.; Gresham, C. [Clemson Univ., Georgetown, SC (United States). Baruch Forest Inst.; Volin, J.C. [Florida Atlantic Univ., Davie, FL (United States). Div. of Science; Bowman, W.D. [Inst. of Arctic and Alpine Research, Boulder, CO (United States). Mountain Research Station]|[Univ. of Colorado, Boulder, CO (United States). Dept. of Evolutionary, Population, and Organismic Biology

1999-09-01

Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here the authors address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A{sub max}), leaf diffusive conductance (G{sub S}), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N{sub mass}), SLA, G{sub S}, and A{sub max} were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships among key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A{sub max} for a given level of G{sub S} and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A{sub max}, N, and SLA) while a second axis reflected climate, G{sub S}, and other area-based leaf traits.

The Brazilian Pampa: A Fragile Biome

Directory of Open Access Journals (Sweden)

Valdir Marcos Stefenon

2009-12-01

Full Text Available Biodiversity is one of the most fundamental properties of Nature. It underpins the stability of ecosystems, provides vast bioresources for economic use, and has important cultural significance for many people. The Pampa biome, located in the southernmost state of Brazil, Rio Grande do Sul, illustrates the direct and indirect interdependence of humans and biodiversity. The Brazilian Pampa lies within the South Temperate Zone where grasslands scattered with shrubs and trees are the dominant vegetation. The soil, originating from sedimentary rocks, often has an extremely sandy texture that makes them fragile—highly prone to water and wind erosion. Human activities have converted or degraded many areas of this biome. In this review we discuss our state-of-the-art knowledge of the diversity and the major biological features of this regions and the cultural factors that have shaped it. Our aim is to contribute toward a better understanding of the current status of this special biome and to describe how the interaction between human activities and environment affects the region, highlighting the fragility of the Brazilian Pampa.

Farm Shop : Augmenter l'accès aux matières premières agricoles au ...

International Development Research Centre (IDRC) Digital Library (Canada)

Farm Shop est un modèle de franchise social novateur qui permet d'obtenir des matières premières d'excellente qualité à des prix abordables grâce à des économies d'échelle. Il forme également des franchisés et des agriculteurs sur la façon d'utiliser les matières premières. Au cours de ses trois premières années ...

Res Publica v respublike / Roman Gornev

Index Scriptorium Estoniae

Gornev, Roman

2002-01-01

Järg 29. november nr. 48 lk. 7. Res Publica - uue poliitika partei. Res Publica Ida-Virumaal, partei juhtfiguurid, Res Publica Kohtla-Järvel. Koalitsioonileping Keskerakonnaga viis konfliktini partei juhtkonnaga. Kohtla-Järve Res Publica kohaliku organisatsiooni konflikti partei juhtkonnaga kommenteerib Hants Hint

biojs-io-biom, a BioJS component for handling data in Biological Observation Matrix (BIOM format [version 2; referees: 1 approved, 2 approved with reservations

Directory of Open Access Journals (Sweden)

Markus J. Ankenbrand

2017-01-01

Full Text Available The Biological Observation Matrix (BIOM format is widely used to store data from high-throughput studies. It aims at increasing interoperability of bioinformatic tools that process this data. However, due to multiple versions and implementation details, working with this format can be tricky. Currently, libraries in Python, R and Perl are available, whilst such for JavaScript are lacking. Here, we present a BioJS component for parsing BIOM data in all format versions. It supports import, modification, and export via a unified interface. This module aims to facilitate the development of web applications that use BIOM data. Finally, we demonstrate its usefulness by two applications that already use this component. Availability: https://github.com/molbiodiv/biojs-io-biom, https://dx.doi.org/10.5281/zenodo.218277

MATER - Pianeta Terra-Mare: an interactive and multidisciplinary approach to Geosphere sciences

Science.gov (United States)

Piangiamore, Giovanna Lucia; Fanelli, Emanuela; Furia, Stefania; Garau, Daniela; Merlino, Silvia; Musacchio, Gemma; Carla Centineo, Maria

2016-04-01

Recent studies demonstrate that Earth and Marine Sciences are not properly treated in scholastic programs and in textbooks are included in a superficial way. These topics are interdisciplinary and experimental (biology, ecology, oceanography and geology) and the recent advance in these fields is strictly linked to technologic improvement. School cannot keep up with the huge advances of knowledge experimented in the last 20 years, also for the lack of didactic laboratories sufficiently updated to support experimental activities. In this context, in 2014-15 three Italian Research Institutes (INGV, ISMAR-CNR and ENEA-CRAM) have decided to support the Unified School District "ISA 10"of Lerici (Liguria, Italy) - comprehensive of kindergartner, primary and middle schools - to develop the project MATER - Pianeta Terra-Mare (Planet Earth and Sea). The acronym MATER (MARe and TERra) has also a gender value, as people involved in the projects were women, mostly researchers and teachers, which have worked side by side with other women belonging to environmental and cultural associations of the territory. This heterogeneous group has a common objective: to promote the diffusion of a scientific culture and to sensitize students from 3 to 14 years towards problems occurring in marine and terrestrial environments, fostering the settlement of a sustainable attitude to the exploitation of natural resources and consciousness to natural hazards, such as earthquakes and floods, quite common in the Ligurian region. MATER has been considered as one of the best projects funded by MIUR (Italian Ministry of Education, University and Research) inside the Dissemination of Scientific and Technological Culture call for the year 2014. Natural hazards (Planet Earth) and the chemical-physical aspects and resources of the marine environment (Planet Sea) were the two modules of the project. Planet Earth developed through Piovono Idee! (Cloudy with a chance of Ideas!), an interactive exhibition on

Modelling insights on the partition of evapotranspiration components across biomes

Science.gov (United States)

Fatichi, Simone; Pappas, Christoforos

2017-04-01

Recent studies using various methodologies have found a large variability (from 35 to 90%) in the ratio of transpiration to total evapotranspiration (denoted as T:ET) across biomes or even at the global scale. Concurrently, previous results suggest that T:ET is independent of mean precipitation and has a positive correlation with Leaf Area Index (LAI). We used the mechanistic ecohydrological model, T&C, with a refined process-based description of soil resistance and a detailed treatment of canopy biophysics and ecophysiology, to investigate T:ET across multiple biomes. Contrary to observation-based estimates, simulation results highlight a well-constrained range of mean T:ET across biomes that is also robust to perturbations of the most sensitive parameters. Simulated T:ET was confirmed to be independent of average precipitation, while it was found to be uncorrelated with LAI across biomes. Higher values of LAI increase evaporation from interception but suppress ground evaporation with the two effects largely cancelling each other in many sites. These results offer mechanistic, model-based, evidence to the ongoing research about the range of T:ET and the factors affecting its magnitude across biomes.

La prosodia como identificador biométrico

OpenAIRE

Farrús i Cabeceran, Mireia

2011-01-01

La biometría tiene como objetivo el reconocimiento de personas mediante uno o más identificadores biométricos como la voz, la cara o las huellas dactilares, entre otros. Gracias a la buena aceptación social y el poco intrusismo en los individuos, la voz ha sido, tradicionalmente, uno de los identificadores más utilizados en los sistemas biométricos. Estos sistemas de reconocimiento basados en la voz utilizan, habitualmente, características relacionadas con el espectro de la voz. No obstante, ...

On coupling global biome models with climate models

OpenAIRE

Claussen, M.

1994-01-01

The BIOME model of Prentice et al. (1992; J. Biogeogr. 19: 117-134), which predicts global vegetation patterns in equilibrium with climate, was coupled with the ECHAM climate model of the Max-Planck-Institut fiir Meteorologie, Hamburg, Germany. It was found that incorporation of the BIOME model into ECHAM, regardless at which frequency, does not enhance the simulated climate variability, expressed in terms of differences between global vegetation patterns. Strongest changes are seen only betw...

Cross-linkable graphene oxide embedded nanocomposite hydrogel with enhanced mechanics and cytocompatibility for tissue engineering.

Science.gov (United States)

Liu, Xifeng; Miller, A Lee; Waletzki, Brian E; Lu, Lichun

2018-05-01

Graphene oxide (GO) is an attractive material that can be utilized to enhance the modulus and conductivities of substrates and hydrogels. To covalently cross-link graphene oxide sheets into hydrogels, abundant cross-linkable double bonds were introduced to synthesize the graphene-oxide-tris-acrylate sheet (GO-TrisA). Polyacrylamide (PAM) nanocomposite hydrogels were then fabricated with inherent covalently and permanently cross-linked GO-TrisA sheets. Results showed that the covalently cross-linked GO-TrisA/PAM nanocomposite hydrogel had enhanced mechanical strength, thermo stability compared with GO/PAM hydrogel maintained mainly by hydrogen bonding between PAM chains and GO sheets. In vitro cell study showed that the covalently cross-linked rGO-TrisA/PAM nanocomposite hydrogel had excellent cytocompatibility after in situ reduction. These results suggest that rGO-TrisA/PAM nanocomposite hydrogel holds great potential for tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1247-1257, 2018. © 2018 Wiley Periodicals, Inc.

The fabrication of well-interconnected polycaprolactone/hydroxyapatite composite scaffolds, enhancing the exposure of hydroxyapatite using the wire-network molding technique.

Science.gov (United States)

Cho, Yong Sang; Hong, Myoung Wha; Jeong, Hoon-Jin; Lee, Seung-Jae; Kim, Young Yul; Cho, Young-Sam

2017-11-01

In this study, the fabrication method was proposed for the well-interconnected polycaprolactone/hydroxyapatite composite scaffold with exposed hydroxyapatite using modified WNM technique. To characterize well-interconnected scaffolds in terms of hydroxyapatite exposure, several assessments were performed as follows: morphology, mechanical property, wettability, calcium ion release, and cell response assessments. The results of these assessments were compared with those of control scaffolds which were fabricated by precision extruding deposition (PED) apparatus. The control PED scaffolds have interconnected pores with nonexposed hydroxyapatite. Consequently, cell attachment of proposed WNM scaffold was improved by increased hydrophilicity and surface roughness of scaffold surface resulting from the exposure of hydroxyapatite particles and fabrication process using powders. Moreover, cell proliferation and differentiation of WNM scaffold were increased, because the exposure of hydroxyapatite particles may enhance cell adhesion and calcium ion release. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2315-2325, 2017. © 2016 Wiley Periodicals, Inc.

3D bioprinting and its in vivo applications.

Science.gov (United States)

Hong, Nhayoung; Yang, Gi-Hoon; Lee, JaeHwan; Kim, GeunHyung

2018-01-01

The purpose of 3D bioprinting technology is to design and create functional 3D tissues or organs in situ for in vivo applications. 3D cell-printing, or additive biomanufacturing, allows the selection of biomaterials and cells (bioink), and the fabrication of cell-laden structures in high resolution. 3D cell-printed structures have also been used for applications such as research models, drug delivery and discovery, and toxicology. Recently, numerous attempts have been made to fabricate tissues and organs by using various 3D printing techniques. However, challenges such as vascularization are yet to be solved. This article reviews the most commonly used 3D cell-printing techniques with their advantages and drawbacks. Furthermore, up-to-date achievements of 3D bioprinting in in vivo applications are introduced, and prospects for the future of 3D cell-printing technology are discussed. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 444-459, 2018. © 2017 Wiley Periodicals, Inc.

Proliferative activity of elastin-like-peptides depends on charge and phase transition.

Science.gov (United States)

Yuan, Yuan; Koria, Piyush

2016-03-01

Elastin-like-peptides (ELPs) are stimulus-responsive protein-based polymers and are attractive biomaterials due to their biocompatibility and unique properties. This study shows that in addition to their physical properties, ELPs have biological activities that are conducive to tissue regeneration. Specifically, we found that ELPs induce fibroblast proliferation via cell surface heparan sulfate proteoglycans (HSPG). Furthermore, our data suggests that ELP based materials with differential proliferative potential can be designed by controlling the interaction of ELPs with HSPGs by incorporating either hydrophobic or positively charged residues within the ELP sequence. Fibroblast proliferation is important for granulation tissue formation which is important in chronic wounds as well as in healing of other tissues. The customizable biological activity of ELPs coupled with their unique physical properties will enable us to design novel, sustainable and cost effective therapies for different tissue regeneration applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 697-706, 2016. © 2015 Wiley Periodicals, Inc.

Effect of hyaluronic acid in bone formation and its applications in dentistry.

Science.gov (United States)

Zhao, Ningbo; Wang, Xin; Qin, Lei; Zhai, Min; Yuan, Jing; Chen, Ji; Li, Dehua

2016-06-01

Hyaluronic acid (HA), the simplest glycosaminoglycan, participates in several important biological procedures, including mediation of cellular signaling, regulation of cell adhesion and proliferation, and manipulation of cell differentiation. The effect of HA on cell proliferation and differentiation depends on its molecular weight (MW) and concentration. Moreover, the properties of high viscosity, elasticity, highly negative charge, biocompatibility, biodegradability, and nonimmunogenicity make HA attractive in tissue engineering and disease treatment. This review comprises an overview of the effect of HA on cell proliferation and differentiation in vitro, the role of HA in bone regeneration in vivo, and the clinical applications of HA in dentistry, focusing on the mechanism underlining the effect of MW and concentration of HA on cell proliferation and osteogenic differentiation. It is expected that practical progress of HA both in laboratory-based experiments and clinical applications will be achieved in the next few years. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1560-1569, 2016. © 2016 Wiley Periodicals, Inc.

The combined effect of thermal and chemotherapy on HeLa cells using magnetically actuated smart textured fibrous system.

Science.gov (United States)

Tiwari, Pranav; Agarwal, Sakshi; Srivastava, Sachchidanand; Jain, Shilpee

2018-01-01

Thermal therapy combined with chemotherapy is one of the advanced and efficient methods to eradicate cancer. In this work, we fabricated magnetically actuated smart textured (MAST) fibrous systems and studied their candidacy for cancer treatment. The polycaprolactone-Fe 3 O 4 based MAST fibers were fabricated using electrospinning technique. These MAST fibrous systems contained carbogenic quantum dots as a tracking agent and doxorubicin hydrochloride anticancer drug. Additionally, as fabricated MAST fibrous systems were able to deliver anticancer drug and heat energy simultaneously to kill HeLa cells in a 10 min period in vitro. After treatment, the metabolic activity and morphology of HeLa cells were analyzed. In addition, the mechanism of cell death was studied using flow cytometry. Interestingly, the navigation of these systems in the fluid can be controlled with the application of gradient magnetic field. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 40-51, 2018. © 2016 Wiley Periodicals, Inc.

Three-dimensional patterning in biomedicine: Importance and applications in neuropharmacology.

Science.gov (United States)

Vikram Singh, Ajay; Gharat, Tanmay; Batuwangala, Madu; Park, Byung-Wook; Endlein, Thomas; Sitti, Metin

2018-04-01

Nature manufactures biological systems in three dimensions with precisely controlled spatiotemporal profiles on hierarchical length and time scales. In this article, we review 3D patterning of biological systems on synthetic platforms for neuropharmacological applications. We briefly describe 3D versus 2D chemical and topographical patterning methods and their limitations. Subsequently, an overview of introducing a third dimension in neuropharmacological research with delineation of chemical and topographical roles is presented. Finally, toward the end of this article, an explanation of how 3D patterning has played a pivotal role in relevant fields of neuropharmacology to understand neurophysiology during development, normal health, and disease conditions is described. The future prospects of organs-on-a--like devices to mimic patterned blood-brain barrier in the context of neurotherapeutic discovery and development for the prioritization of lead candidates, membrane potential, and toxicity testing are also described. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1369-1382, 2018. © 2017 Wiley Periodicals, Inc.

Res Publica objedinjajetsja s Sojuzom Otetshestva

Index Scriptorium Estoniae

2006-01-01

Res Publica ja Isamaaliidu liitumisel tekib uus erakond - Eesti Eest!. Ida-Viru Isamaaliidu ja Res Publica esimeeste Hans Pindre, Vladislav Ponjatovski ning Narva Res Publica endise liidri Nikolai Golubevi arvamused

Effect of Electric-current Pulses on Grain-structure Evolution in Cryogenically Rolled Copper

Science.gov (United States)

2014-11-01

severely deformed dilute aluminium alloy . Acta Mater. 56, 1619 (2008). 4. T. Konkova, S. Mironov, A. Korznikov, and S.L. Semiatin: Microstructural response...phase transformation and variant selection by electric current pulses in a Cu-Zn alloy . J. Mater. Res. 29, 975 (2014). 13. I.Sh. Valeev and Z.G

Muusikapassioon mõttepeeglis. Täna kõlab "Stabat Mater" / Anne Peäske

Index Scriptorium Estoniae

Peäske, Anne, 1946-

2005-01-01

Arvo Pärdi "Passio" ettekandest 11.sept. Rakvere Kolmainu kirikus. Elmo Lööve, Raivo Palmaru, Jaan Rääts, Toivo Tulev, Aarne Talvik, Ingmar Kurg, Olev Oja ja Eleonora Pärt Arvo Pärdi muusikast. A. Pärdi "Stabat Mater" ansambli Theatre of Voices esituses 14. sept. Rakvere Kolmainu kirikus

Immunohistochemical profile of neurotrophins in human cranial dura mater and meningiomas.

Science.gov (United States)

Artico, Marco; Bronzetti, Elena; Pompili, Elena; Ionta, Brunella; Alicino, Valentina; D'Ambrosio, Anna; Santoro, Antonio; Pastore, Francesco S; Elenkov, Ilia; Fumagalli, Lorenzo

2009-06-01

The immunohistochemical profile of neurotrophins and their receptors in the human cranial dura mater was studied by examining certain dural zones in specimens harvested from different regions (frontal, temporal, parietal and occipital). Dural specimens were obtained during neurosurgical operations performed in ten patients for surgical treatment of intracranial lesions (meningiomas, traumas, gliomas, vascular malformations). The dural fragments were taken from the area of the craniotomy at least 8 cm from the lesion as well as from the area in which the meningioma had its dural attachment. Immunohistochemical characterization and distribution of neurotrophins, with their receptors, were analyzed. The concrete role played by these neurotrophic factors in general regulation, vascular permeability, algic responsivity and release of locally active substances in the human dura mater is still controversial. Our study revealed a general structural alteration of dural tissue due to the invasivity of meningiomatous lesions, together with an improved expression of brain derived neurotrophic factor (BDNF) in highly proliferating neoplastic cells and an evident production of nerve growth factor (NGF) in inflammatory cells, suggesting that BDNF has a role in supporting the proliferation rate of neoplastic cells, while NGF is involved in the activation of a chronic inflammatory response in neoplastic areas.

Mid- to Late-Holocene pollen-based biome reconstructions for Colombia

NARCIS (Netherlands)

Marchant, R.; Behling, H.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Geel, van B.; Hammen, van der T.; Reenen, van T.; Wille, M.

2001-01-01

The assignment of Colombian pollen data to biomes allows the data to be synthesised at 10 `time windows' from the present-day to 6000 radiocarbon years before present (BP). The modern reconstructed biomes are compared to a map of modern potential vegetation to check the applicability of the method

Biosphere 2's Marsh Biome

Science.gov (United States)

Molnar, Jennifer; Goodridge, Kelven

1997-01-01

The Marsh Biome, which was modeled after the mangroves and marshes of southwest Florida, has an area of 441.2 sq m separated into three hydrologically independent sections: the Freshwater, Oligohaline and Salt Marshes. The divisions are made based on their salinity (approximately 0, 4, and 34 ppt. respectively), but they also contain different biological communities. The Freshwater and Oligohaline Marshes are mostly filled with various grasses and several trees, while the Salt Marsh houses regions of red, black, and white mangroves (Rhizophora mangle, Avicennia germinans, and Languncularia racemosa respectively). Overall, there are an estimated 80 species of plants within the biome. Water in the Salt Marsh follows a meandering stream from the algal turf scrubbers (apparatuses that clean the water of its nutrients and heavy metals while increasing dissolved oxygen levels) which have an outlet in the Salt Marsh section near sites 4 and 5 to the Fringing Red Mangrove section. The sections of the Salt Marsh are separated by walls of concrete with openings to allow the stream to flow through. Throughout this study, conducted through the months of June and July, many conditions within the biome remained fairly constant. The temperature was within a degree or two of 25 C, mostly depending on whether the sample site was in direct sunlight or shaded. The pH throughout the Salt Marsh was 8.0 +/- 0.2, and the lower salinity waters only dropped below this soon after rains. The water rdepth and dissolved oxygen varied, however, between sites.

Hypoglycemic depression of RES function.

Science.gov (United States)

Buchanan, B J; Filkins, J P

1976-07-01

The intravascular removal rates of colloidal carbon and of biologically active endotoxin by the reticuloendothelial system (RES) were evaluated as a function of blood-glucose levels. There was a significant negative correlation of carbon clearance half time on blood glucose in both saline-treated and insulin-treated rats. Insulin hypoglycemia depressed RES carbon clearance with the maximal effect occurring at blood glucose values below 30 mg/dl. Insulin hypoglycemia also severely impaired the intravascular removal of endotoxin as evaluated by lethality bioassay in lead-sensitized rats. It is concluded that blood glucose may modulate RES phagocytic function and that the hypoglycemia of endotoxin shock may augment the shock state due to impairment of RES host defense clearance functions.

Creutzfeldt-Jakob disease and lyophilised dura mater grafts: report of two cases.

Science.gov (United States)

Esmonde, T; Lueck, C J; Symon, L; Duchen, L W; Will, R G

1993-01-01

Two further cases of Creutzfeldt-Jakob disease (CJD) in association with cadaveric dura mater grafts are described. The clinical features of all such reported cases resemble more closely those of sporadic CJD, in contrast with kuru and the cases of CJD which have arisen after therapy with human pituitary-derived growth hormone. This observation may reflect the route of inoculation of the agent. PMID:8410042

Res Publica kogub uut hoogu / Andres Jalak

Index Scriptorium Estoniae

Jalak, Andres, 1953-

2005-01-01

Kommenteerides Res Publica senise esimehe ja endise peaministri Juhan Partsi ning uueks esimeheks valitud Taavi Veskimäe kõnet Res Publica üldkogul, väljendab Res Publica fraktsiooni aseesimees usku, et Res Publica juhtimisel suudetakse 2007. aasta parlamendivalimistel taastada tulevikku suunatud mõtlemisega valitsus

Factors affecting ammonium uptake in streams - an inter-biome perspective

Science.gov (United States)

Jackson R Webster; Partick J. Mulholland; Jennifer L. Tanks; H. Maurice Valett; Walter K. Dodds; Bruce J. Peterson; William B. Bowden; Clifford N. Dahm; Stuart Findlay; Stanley V. Gregory; Nancy B. Grimm; Stephen K. Hamilton; Sherri L. Johnson; Eugenia Marti; William H. McDowell; Judy L. Meyer; Donna D. Morrall; Steven A. Thomas; Wilfred M. Wollhem

2003-01-01

1. The Lotic Intersite Nitrogen experiment (LINX) was a coordinated study of the relationships between North American biomes and factors governing ammonium uptake in streams. Our objective was to relate inter-biome variability of ammonium uptake to physical, chemical and biological processes. 2. Data were collected from 11 streams ranging from arctic to tropical and...

Buli. Mater. Sci., Vol. 10, No. 4, July 1988, pp. 367-372. (C

Indian Academy of Sciences (India)

Mater. Sci., Vol. 10, No. 4, July 1988, pp. 367-372. (C) Printed in India. Studies on iron-chromium redox storage system. SH PAWAR, R D MADHALE, P S PATIL and CD LOKHANDE. Department of Physics, Shivaji University, Kolhapur 416 004, India. Abstract. The performance of the redox storage battery based on the Fe-Cr ...

Conserving the Brazilian semiarid (Caatinga) biome under climate change

DEFF Research Database (Denmark)

Oliveira, Guilherme de; Bastos Araujo, Miguel; Rangel, Thiago Fernado

2012-01-01

to assess changes in climate suitability across individual species ranges, ensemble forecasting was used based on seven bioclimatic envelope models, three atmosphere–ocean general circulation models, and two greenhouse emission gas scenarios for 2020, 2050, and 2080. We found that most species will gain...... additional threats to the biome’s biodiversity. Here, we ask if the remnants of natural vegetation in Caatinga biome, where endemic terrestrial vertebrate species occur, are likely to retain more climatic suitability under climate change scenarios than other less pristine areas of the biome. In order......The Caatinga is a semiarid biome of the northeast of Brazil with only 1 % of its territory currently conserved. The biome’s biodiversity is highly threatened due to exposure to land conversion for agricultural and cattle ranch. Climate forecasts predict increases in aridity, which could pose...

Description of the Fynbos Biome Project

CSIR Research Space (South Africa)

Kruger, FJ

1978-06-01

Full Text Available The objectives, organization and research programme of the Fynbos Biome Project being undertaken in the south-west and southern Cape are described. The project is a cooperative multi-disciplinary study of the ecological characteristics, structure...

Does a General Temperature-Dependent Q10 Model of Soil Respiration Exist at Biome and Global Scale?

Institute of Scientific and Technical Information of China (English)

Hua CHEN; Han-Qin TIAN

2005-01-01

Soil respiration (SR) is commonly modeled by a Q10 (an indicator of temperature sensitivity)function in ecosystem models. Q10is usually treated as a constant of 2 in these models, although Q10 value of SR often decreases with increasing temperatures. It remains unclear whether a general temperaturedependent Q10 model of SR exists at biome and global scale. In this paper, we have compiled the long-term Q10 data of 38 SR studies ranging from the Boreal, Temperate, to Tropical/Subtropical biome on four continents.Our analysis indicated that the general temperature-dependent biome Q10 models of SR existed, especially in the Boreal and Temperate biomes. A single-exponential model was better than a simple linear model in fitting the average Q10 values at the biome scale. Average soil temperature is a better predictor of Q10 value than average air temperature in these models, especially in the Boreal biome. Soil temperature alone could explain about 50% of the Q10 variations in both the Boreal and Temperate biome single-exponential Q10 model. Q10 value of SR decreased with increasing soil temperature but at quite different rates among the three biome Q10 models. The k values (Q10 decay rate constants) were 0.09, 0.07, and 0.02/℃ in the Boreal, Temperate, and Tropical/Subtropical biome, respectively, suggesting that Q10 value is the most sensitive to soil temperature change in the Boreal biome, the second in the Temperate biome, and the least sensitive in the Tropical/Subtropical biome. This also indirectly confirms that acclimation of SR in many soil warming experiments probably occurs. The k value in the "global" single-exponential Q10 model which combined both the Boreal and Temperate biome data set was 0.08/℃. However, the global general temperature-dependent Q10model developed using the data sets of the three biomes is not adequate for predicting Q10 values of SR globally.The existence of the general temperature-dependent Q10 models of SR in the Boreal and

The effect of heterogeneous landscape dynamics on ecotone types at two convergent semi-arid biomes

Science.gov (United States)

Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsca...

Increasing atmospheric CO2 overrides the historical legacy of multiple stable biome states in Africa.

Science.gov (United States)

Moncrieff, Glenn R; Scheiter, Simon; Bond, William J; Higgins, Steven I

2014-02-01

The dominant vegetation over much of the global land surface is not predetermined by contemporary climate, but also influenced by past environmental conditions. This confounds attempts to predict current and future biome distributions, because even a perfect model would project multiple possible biomes without knowledge of the historical vegetation state. Here we compare the distribution of tree- and grass-dominated biomes across Africa simulated using a dynamic global vegetation model (DGVM). We explicitly evaluate where and under what conditions multiple stable biome states are possible for current and projected future climates. Our simulation results show that multiple stable biomes states are possible for vast areas of tropical and subtropical Africa under current conditions. Widespread loss of the potential for multiple stable biomes states is projected in the 21st Century, driven by increasing atmospheric CO2 . Many sites where currently both tree-dominated and grass-dominated biomes are possible become deterministically tree-dominated. Regions with multiple stable biome states are widespread and require consideration when attempting to predict future vegetation changes. Testing for behaviour characteristic of systems with multiple stable equilibria, such as hysteresis and dependence on historical conditions, and the resulting uncertainty in simulated vegetation, will lead to improved projections of global change impacts. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Res Publica aps / Erkki Bahovski

Index Scriptorium Estoniae

Bahovski, Erkki, 1970-

2003-01-01

Autori sõnul tekitavad tänavatel ülesseatud postrid, kus peaminister Juhan Parts kutsub üles ütlema "jah" Euroopa Liidule, kummastust, sest ehkki on tegemist Res Publica kampaaniaga, on tavainimesel raske vahet teha valitsuse justkui neutraalse referendumikampaania ja Res Publica "jah"-kampaania vahel

Use of BIOME-BGC to simulate water and carbon fluxes within Mediterranean macchia

OpenAIRE

Chiesi M; Chirici G; Corona P; Duce P; Salvati R; Spano D; Vaccari FP; Maselli F

2012-01-01

The biogeochemical model BIOME-BGC is capable to estimate the main ecophysiological processes characterising all terrestrial ecosystems. To this aim it needs to be properly adapted to reproduce the behaviour of each biome type through a calibration phase. The aim of this paper is to adapt BIOME-BGC to reproduce the evapotranspiration (ET) and photosynthesis (GPP) of Mediterranean macchia spread all over Italy. Ten different sites were selected in the Centre-South of Italy and their gross prim...

Shift of biome patterns due to simulated climate variability and climate change

International Nuclear Information System (INIS)

Claussen, M.

1993-01-01

The variability of simulated equilibrium-response patterns of biomes caused by simulated climate variability and climate shift is analysed. This investigation is based on various realisations of simulated present-day climate and climate shift. It has been found that the difference between biomes computed from three 10-year climatologies and from the corresponding 30-year climatology, simulated by the Hamburg climate model at T21 resolution, amounts to approximately 6% of the total land area, Antarctica excluded. This difference is mainly due to differences in annual moisture availability and winter temperatures. When intercomparing biomes from the 10-year climatologies a 10% difference is seen, but there is no unique difference pattern. In contrast to the interdecadal variability, the shift of conditions favorable for biomes due to a shift in climate in the next 100 years, caused by an increase in sea-surface temperatures and atmospheric CO 2 , reveals a unique trend pattern. It turns out that the strongest and most significant signal is the north-east shift of conditions for boreal biomes. This signal is caused by an increase of annual temperature sums as well as mean temperatures of the coldest and warmest months. Trends in annual moisture availability are of secondary importance globally. Regionally, a decrease in water availability affects biomes in Central and East Europe and an increase of water availability leads to a potential increase in tropical rain forest. In total, all differences amount to roughly 30% of the total land surface, Antarctica excluded. (orig./KW)

User's Guide to Biome Information from the United States International Biological Program (IBP). First Edition.

Science.gov (United States)

Hinckley, A. Dexter; Haug, Peter T.

This publication is a guide to the biome research conducted under the International Biological Program. The guide lists biome researchers by interest and by biome as well as a central list. A site list, map, information sources section reporting abstracts, bibliographies, journals, books, evaluations, and data books are also included. Three…

Forgotten forests--issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study.

Science.gov (United States)

Särkinen, Tiina; Iganci, João R V; Linares-Palomino, Reynaldo; Simon, Marcelo F; Prado, Darién E

2011-11-24

South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be particularly useful for mapping

Climate change in Inner Mongolia from 1955 to 2005-trends at regional, biome and local scales

Energy Technology Data Exchange (ETDEWEB)

Lu, N; Wilske, B; John, R; Chen, J [Department of Environmental Sciences, University of Toledo, Toledo, OH 43606 (United States); Ni, J, E-mail: nan.lu@utoledo.ed, E-mail: burkhard.wilske@utoledo.ed, E-mail: jni@ibcas.ac.c, E-mail: ranjeet.john@utoledo.ed, E-mail: jiquan.chen@utoledo.ed [Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, D-14473 Potsdam (Germany)

2009-10-15

This study investigated the climate change in Inner Mongolia based on 51 meteorological stations from 1955 to 2005. The climate data was analyzed at the regional, biome (i.e. forest, grassland and desert) and station scales, with the biome scale as our primary focus. The climate records showed trends of warmer and drier conditions in the region. The annual daily mean, maximum and minimum temperature increased whereas the diurnal temperature range (DTR) decreased. The decreasing trend of annual precipitation was not significant. However, the vapor pressure deficit (VPD) increased significantly. On the decadal scale, the warming and drying trends were more significant in the last 30 years than the preceding 20 years. The climate change varied among biomes, with more pronounced changes in the grassland and the desert biomes than in the forest biome. DTR and VPD showed the clearest inter-biome gradient from the lowest rate of change in the forest biome to the highest rate of change in the desert biome. The rates of change also showed large variations among the individual stations. Our findings correspond with the IPCC predictions that the future climate will vary significantly by location and through time, suggesting that adaptation strategies also need to be spatially viable.

Climate change in Inner Mongolia from 1955 to 2005-trends at regional, biome and local scales

International Nuclear Information System (INIS)

Lu, N; Wilske, B; John, R; Chen, J; Ni, J

2009-01-01

This study investigated the climate change in Inner Mongolia based on 51 meteorological stations from 1955 to 2005. The climate data was analyzed at the regional, biome (i.e. forest, grassland and desert) and station scales, with the biome scale as our primary focus. The climate records showed trends of warmer and drier conditions in the region. The annual daily mean, maximum and minimum temperature increased whereas the diurnal temperature range (DTR) decreased. The decreasing trend of annual precipitation was not significant. However, the vapor pressure deficit (VPD) increased significantly. On the decadal scale, the warming and drying trends were more significant in the last 30 years than the preceding 20 years. The climate change varied among biomes, with more pronounced changes in the grassland and the desert biomes than in the forest biome. DTR and VPD showed the clearest inter-biome gradient from the lowest rate of change in the forest biome to the highest rate of change in the desert biome. The rates of change also showed large variations among the individual stations. Our findings correspond with the IPCC predictions that the future climate will vary significantly by location and through time, suggesting that adaptation strategies also need to be spatially viable.

Padenije Res Publica / Viktoria Jürmann

Index Scriptorium Estoniae

Jürmann, Viktoria

2005-01-01

Res Publica üks rajajatest, Rein Taagepera, lahkus parteist, süüdistades erakonda paremtsentristlikust maailmavaatest loobumises. Res Publica Riigikogu fraktsioon tahab avaldada umbusaldust haridus- ja teadusminister Mailis Repsile

S2Biom database with logistical components of the biomass value chain

NARCIS (Netherlands)

Annevelink, E.; Groot, de H.L.E.; Shah, N.; Giarola, S.; Pantaleo, M.; Anttila, P.; Vis, Martijn; Raa, te Rik; Berg, van den Douwe; Gabrielle, B.

2015-01-01

The S2Biom project (www.s2biom.eu) - Delivery of sustainable supply of non-food biomass to support
a resource-efficient Bioeconomy in Europe - supports sustainable delivery chains of non-food biomass feedstock.
This poses a logistical challenge because the quality and handling

Lõhe Res Publicas / Eve Heinla

Index Scriptorium Estoniae

Heinla, Eve, 1966-

2005-01-01

Tallinna linnapea Tõnis Palts on vastu Tallinna volikogu Res Publica fraktsiooni esimehe Toomas Tautsi abikaasa Kristina Tautsi tööleasumisele Lääne-Tallinna keskhaigla haldusjuhina. T. Paltsi kirjast Res Publica Tallinna piirkonna juhatusele. Lisa: Kuidas lahvatas pealinna võimutüli. Kommenteerivad: Maret Maripuu, Tõnis Palts, Vladimir Maslov

10 teesi Res Publica valitsemisprogrammist aastani 2007

Index Scriptorium Estoniae

2004-01-01

Ilmunud ka: Ottshjot narodu Estonii. Res Publica 2003, 2004, lk. 4-5, 8-9. Res Publica valitsemisprogrammi lubadustest ja täitmisest. Vt. lk. 8-9 Res Publica ministrite olulisemad tegevused 2004. aastal - lühiülevaate teevad Ken-Marti Vaher, Taavi Veskimägi, Marko Pomerants, Toivo Maimets

Isamaaliidu ühinemisjutt ajas Res Publica keema / Toomas Sildam

Index Scriptorium Estoniae

Sildam, Toomas, 1961-

2005-01-01

Ilmunud ka: Postimees : na russkom jazõke 14. nov., lk 3. Isamaaliidu esimehe Tõnis Lukase ettepanekut Isamaaliidu ja Res Publica ühinemiseks pooldavad ka Res Publica eestseisuse liikmed Juhan Parts ja Tõnis Palts, kuid Res Publica esimehe Taavi Veskimäe kinnitusel läheb Res Publica 2007. aasta parlamendivalimistele vastu iseseisvalt. Lisa: Isamaaliit ja Res Publica

Expanding the global network of protected areas to save the imperiled mediterranean biome.

Science.gov (United States)

Underwood, Emma C; Klausmeyer, Kirk R; Cox, Robin L; Busby, Sylvia M; Morrison, Scott A; Shaw, M Rebecca

2009-02-01

: Global goals established by the Convention on Biological Diversity stipulate that 10% of the world's ecological regions must be effectively conserved by 2010. To meet that goal for the mediterranean biome, at least 5% more land must be formally protected over the next few years. Although global assessments identify the mediterranean biome as a priority, without biologically meaningful analysis units, finer-resolution data, and corresponding prioritization analysis, future conservation investments could lead to more area being protected without increasing the representation of unique mediterranean ecosystems. We used standardized analysis units and six potential natural vegetation types stratified by 3 elevation zones in a global gap analysis that systematically explored conservation priorities across the mediterranean biome. The highest levels of protection were in Australia, South Africa, and California-Baja California (from 9-11%), and the lowest levels of protection were in Chile and the mediterranean Basin (biome only one of the six vegetation types--mediterranean shrubland--exceeded 10% protection. The remaining vegetation types--grassland, scrub, succulent dominated, woodland, and forest--each had biome, we identified biodiversity assemblages with 30% conversion and suggest that these assemblages be elevated to high-priority status in future conservation efforts.

Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

Directory of Open Access Journals (Sweden)

Särkinen Tiina

2011-11-01

Full Text Available Abstract Background South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF biome using herbarium data of habitat specialist species. Results Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1 poor spatial resolution, and (2 poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in

Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

Science.gov (United States)

2011-01-01

Background South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Results Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be

Terrestrial ecology. Comprehensive study of the grassland biome

International Nuclear Information System (INIS)

Anon.

1976-01-01

Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

The phylogeny and biogeography of Hakea (Proteaceae) reveals the role of biome shifts in a continental plant radiation.

Science.gov (United States)

Cardillo, Marcel; Weston, Peter H; Reynolds, Zoe K M; Olde, Peter M; Mast, Austin R; Lemmon, Emily M; Lemmon, Alan R; Bromham, Lindell

2017-08-01

The frequency of evolutionary biome shifts during diversification has important implications for our ability to explain geographic patterns of plant diversity. Recent studies present several examples of biome shifts, but whether frequencies of biome shifts closely reflect geographic proximity or environmental similarity of biomes remains poorly known. We explore this question by using phylogenomic methods to estimate the phylogeny of Hakea, a diverse Australian genus occupying a wide range of biomes. Model-based estimation of ancestral regions indicates that Hakea began diversifying in the Mediterranean biome of southern Australia in the Middle Eocene-Early Oligocene, and dispersed repeatedly into other biomes across the continent. We infer around 47 shifts between biomes. Frequencies of shifts between pairs of biomes are usually similar to those expected from their geographic connectedness or climatic similarity, but in some cases are substantially higher or lower than expected, perhaps reflecting how readily key physiological traits can be modified to adapt lineages to new environments. The history of frequent biome-shifting is reflected in the structure of present-day assemblages, which tend to be more phylogenetically diverse than null-model expectations. The case of Hakea demonstrates that the radiation of large plant clades across wide geographic areas need not be constrained by dispersal limitation or conserved adaptations to particular environments. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

Science.gov (United States)

Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

1992-10-01

The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tendons, while in the optic nerve sheath the fibrils appear smaller and uniform, similar to those commonly observed in reticular tissues, vessel walls and skin. Freeze-fracture also reveals these fibrils to have different subfibrillar architectures, straight or helical, which correspond to 2 distinct forms of collagen fibril previously described (Raspanti et al. 1989). The other extracellular matrix components also vary with the particular collagen fibril structure. Despite their common embryological derivation, the dura mater, optic nerve sheath and sclera exhibit diversification of their extracellular matrix consistent with the mechanical loads to which these tissues are subjected. Our observations indicate that the outermost sheath of the optic nerve resembles the epineurium of peripheral nerves rather than the dura to which it is commonly likened.

Miks Res Publica kaotas / Juhan Parts

Index Scriptorium Estoniae

Parts, Juhan, 1966-

2004-01-01

Ilmunud ka: Severnoje Poberezhje, 29. juuni 2004, lk. 2; Koit, 29. juuni 2004, lk. 6. Europarlamendi valimiste tulemused erakonnale Res Publica. Juhan Partsi kõne 26. juunil Pärnus toimunud Res Publica volikogul. Lühendatult

"Click" on PLGA-PEG and hyaluronic acid: Gaining access to anti-leishmanial pentamidine bioconjugates.

Science.gov (United States)

Scala, Angela; Piperno, Anna; Micale, Nicola; Mineo, Placido G; Abbadessa, Antonio; Risoluti, Roberta; Castelli, Germano; Bruno, Federica; Vitale, Fabrizio; Cascio, Antonio; Grassi, Giovanni

2017-12-08

Pentamidine (Pent), an antiparasitic drug used for the treatment of visceral leishmaniasis, has been modified with terminal azide groups and conjugated to two different polymer backbones (PLGA-PEG [PP] copolymer and hyaluronic acid [HA]) armed with alkyne end-groups. The conjugation has been performed by Copper Catalyzed Azido Alkyne Cycloaddition (CuAAC) using CuSO 4 /sodium ascorbate as metal source. The novel PP-Pent and HA-Pent bioconjugates are proposed, respectively, as non-targeted and targeted drug delivery systems against Leishmania infections. Moreover, Pent has been encapsulated into PP nanoparticles by the oil-in-water emulsion method, with the aim to compare the biological activity of the bioconjugates with that of the classical drug-loaded delivery system that physically entraps the therapeutic agent. Biological assays against Leishmania infantum amastigote-infected macrophages and primary macrophages revealed that Pent, either covalently conjugated with polymers or loaded into polymeric nanoparticles, turned out to be more potent and less toxic than the free Pent. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Extracellular matrix-derived hydrogels for dental stem cell delivery.

Science.gov (United States)

Viswanath, Aiswarya; Vanacker, Julie; Germain, Loïc; Leprince, Julian G; Diogenes, Anibal; Shakesheff, Kevin M; White, Lisa J; des Rieux, Anne

2017-01-01

Decellularized mammalian extracellular matrices (ECM) have been widely accepted as an ideal substrate for repair and remodelling of numerous tissues in clinical and pre-clinical studies. Recent studies have demonstrated the ability of ECM scaffolds derived from site-specific homologous tissues to direct cell differentiation. The present study investigated the suitability of hydrogels derived from different source tissues: bone, spinal cord and dentine, as suitable carriers to deliver human apical papilla derived mesenchymal stem cells (SCAP) for spinal cord regeneration. Bone, spinal cord, and dentine ECM hydrogels exhibited distinct structural, mechanical, and biological characteristics. All three hydrogels supported SCAP viability and proliferation. However, only spinal cord and bone derived hydrogels promoted the expression of neural lineage markers. The specific environment of ECM scaffolds significantly affected the differentiation of SCAP to a neural lineage, with stronger responses observed with spinal cord ECM hydrogels, suggesting that site-specific tissues are more likely to facilitate optimal stem cell behavior for constructive spinal cord regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 319-328, 2017. © 2016 Wiley Periodicals, Inc.

Alkyl chitosan film-high strength, functional biomaterials.

Science.gov (United States)

Lu, Li; Xing, Cao; Xin, Shen; Shitao, Yu; Feng, Su; Shiwei, Liu; Fusheng, Liu; Congxia, Xie

2017-11-01

Biofilm with strong tensile strength is a topic item in the area of tissue engineering, medicine engineering, and so forth. Here we introduced an alkyl chitosan film with strong tensile strength and its possibility for an absorbable anticoagulation material in vivo was tested in the series of blood test, such as dynamic coagulation time, plasma recalcification time and hemolysis. Alkyl chitosan film was a better biomaterial than traditional chitosan film in the anticoagulation, tissue compatibility and cell compatibility. The unique trait of alkyl chitosan film may be for its greater contact angle and hydrophobicity ability to reduce the adsorption capacity for the blood component and the activity of fibrinolytic enzymes, enhance the antibacterial capacity than chitosan film. Moreover, none of chitosan film or butyl chitosan film exhibited quick inflammation or other disadvantage and degraded quickly by implanted test. Therefore, Alkyl chitosan film is of prospective properties as an implantable, absorbable agent for tissue heals, and this material need further research. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3034-3041, 2017. © 2017 Wiley Periodicals, Inc.

Lithium doped calcium phosphate cement maintains physical mechanical properties and promotes osteoblast proliferation and differentiation.

Science.gov (United States)

Li, Li; Wang, Renchong; Li, Baichuan; Liang, Wei; Pan, Haobo; Cui, Xu; Tang, Jingli; Li, Bing

2017-07-01

Calcium phosphate cement (CPC) has been widely used in bone tissue repairing due to its physical mechanical properties and biocompatibility. Addition of trace element to CPC has shown promising evidence to improve the physical properties and biological activities of CPC. Lithium (Li) has effect on osteoblast proliferation and differentiation. In this study, we incorporated Li to CPC and examined the physical properties of Li/CPC and its effect on osteoblast proliferation and differentiation. We found that Li doped CPC maintained similar setting time, pore size distribution, compressive strength, composition, and morphology as CPC without Li. Additionally, Li doped CPC improved osteoblast proliferation and differentiation significantly compared to CPC without Li. To our knowledge, our results, for the first time, show that Li doped CPC has beneficial effect on osteoblast in cell culture while keeps the excellent physical-mechanical properties of CPC. This study will lead to potential application of Li doped CPC in bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 944-952, 2017. © 2016 Wiley Periodicals, Inc.

Development of electroactive nanofibers based on thermoplastic polyurethane and poly(o-ethoxyaniline) for biological applications.

Science.gov (United States)

Cruz, Karina Ferreira Noronha; Formaggio, Daniela Maria Ducatti; Tada, Dayane Batista; Cristovan, Fernando Henrique; Guerrini, Lilia Müller

2017-02-01

Electroactive nanofibers based on thermoplastic polyurethane (TPU) and poly(alkoxy anilines) produced by electrospinning has been explored for biomaterials applications. The thermoplastic polyurethane is a biocompatible polymer with good mechanical properties. The production of TPU nanofibers requires the application of high voltage during electrospinning in order to prepare uniform mats due to its weak ability to elongate during the process. To overcome this limitation, a conductive polymer can be incorporated to the process, allowing generates mats without defects. In this study, poly(o-ethoxyaniline) POEA doped with dodecylbenzene sulfonic acid (DBSA) was blended with thermoplastic polyurethane (TPU) by solution method. Films were produced by casting and nanofibers were prepared by electrospinning. The effect of the POEA on morphology, distribution of diameter and cell viability of the nanofibers was evaluated. The results demonstrated that the incorporation of POEA in TPU provided to the mats a suitable morphology for cellular growth. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 601-607, 2017. © 2016 Wiley Periodicals, Inc.

An improved correlation to predict molecular weight between crosslinks based on equilibrium degree of swelling of hydrogel networks.

Science.gov (United States)

Jimenez-Vergara, Andrea C; Lewis, John; Hahn, Mariah S; Munoz-Pinto, Dany J

2018-04-01

Accurate characterization of hydrogel diffusional properties is of substantial importance for a range of biotechnological applications. The diffusional capacity of hydrogels has commonly been estimated using the average molecular weight between crosslinks (M c ), which is calculated based on the equilibrium degree of swelling. However, the existing correlation linking M c and equilibrium swelling fails to accurately reflect the diffusional properties of highly crosslinked hydrogel networks. Also, as demonstrated herein, the current model fails to accurately predict the diffusional properties of hydrogels when polymer concentration and molecular weight are varied simultaneously. To address these limitations, we evaluated the diffusional properties of 48 distinct hydrogel formulations using two different photoinitiator systems, employing molecular size exclusion as an alternative methodology to calculate average hydrogel mesh size. The resulting data were then utilized to develop a revised correlation between M c and hydrogel equilibrium swelling that substantially reduces the limitations associated with the current correlation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1339-1348, 2018. © 2017 Wiley Periodicals, Inc.

Bacterial nanocellulose-IKVAV hydrogel matrix modulates melanoma tumor cell adhesion and proliferation and induces vasculogenic mimicry in vitro.

Science.gov (United States)

Reis, Emily M Dos; Berti, Fernanda V; Colla, Guilherme; Porto, Luismar M

2017-12-05

Vasculogenic mimicry process has generated great interest over the past decade. So far, however, there have been only a few matrices available that allow us to study that process in vitro. Here, we have developed an innovative hydrogel platform with defined composition that mimics the structural architecture and biological functions of the extracellular matrix for vasculogenic mimicry of human melanoma cells (SK-MEL-28). We chemically immobilized IKVAV peptide on bacterial nanocellulose (BNC) fibers. BNC-IKVAV hydrogel was found to improve the adhesion and proliferation of SK-MEL-28 cells on the top and bottom surfaces. Particularly, the bottom surface of BNC-IKVAV induced SK-MEL-28 cells to organize themselves as well-established networks related to the vasculogenic mimicry process. Finally, our results showed that not only BNC-IKVAV but also BNC hydrogels can potentially be used as a three-dimensional platform that allows the screening of antitumor drugs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Removable partial denture alloys processed by laser-sintering technique.

Science.gov (United States)

Alageel, Omar; Abdallah, Mohamed-Nur; Alsheghri, Ammar; Song, Jun; Caron, Eric; Tamimi, Faleh

2018-04-01

Removable partial dentures (RPDs) are traditionally made using a casting technique. New additive manufacturing processes based on laser sintering has been developed for quick fabrication of RPDs metal frameworks at low cost. The objective of this study was to characterize the mechanical, physical, and biocompatibility properties of RPD cobalt-chromium (Co-Cr) alloys produced by two laser-sintering systems and compare them to those prepared using traditional casting methods. The laser-sintered Co-Cr alloys were processed by the selective laser-sintering method (SLS) and the direct metal laser-sintering (DMLS) method using the Phenix system (L-1) and EOS system (L-2), respectively. L-1 and L-2 techniques were 8 and 3.5 times more precise than the casting (CC) technique (p laser-sintered and cast alloys were biocompatible. In conclusion, laser-sintered alloys are more precise and present better mechanical and fatigue properties than cast alloys for RPDs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1174-1185, 2018. © 2017 Wiley Periodicals, Inc.

Res Publica otsib kandepinda / Mirko Ojakivi

Index Scriptorium Estoniae

Ojakivi, Mirko

2004-01-01

Res Publica peasekretäri Ott Lumi sõnul on erakond teinud tõsised järeldused Euroopa Parlamendi valimiste tulemusest. Res Publica parlamendifraktsiooni väljasõidul pidas kriitilise kõne erakonna esimees Juhan Parts

Anthropogenic Biomes of the World, Version 2: 1700

Data.gov (United States)

National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1700 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

Anthropogenic Biomes of the World, Version 2: 1900

Data.gov (United States)

National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1900 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

Anthropogenic Biomes of the World, Version 2: 1800

Data.gov (United States)

National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1800 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

Anthropogenic Biomes of the World, Version 2: 2000

Data.gov (United States)

National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 2000 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

Epidural fat interposition between dura mater and spinous process: a new sign for the diagnosis of spondylolysis on MR imaging of the lumbar spine

Energy Technology Data Exchange (ETDEWEB)

Sherif, Hanan; Mahfouz, Ahmed-Emad [Department of Radiology, Hamad Medical Corporation, P.O. Box 3050, Doha (Qatar)

2004-06-01

The purpose of this study was to assess the diagnostic value of epidural fat interposition between the dura mater and spinous process of L5 as an indirect sign of spondylolysis on mid-sagittal MR imaging of the lumbar spine. Mid-sagittal T1-weighted MR images of the lumbar spine of 85 patients with spondylolysis and 93 patients without pars interarticularis fractures were randomized and evaluated by a masked reader. After a training sample of five cases, the reader was asked to note the presence or absence of epidural fat interposition between the dura mater and spinous process of L5 on the randomized images. The epidural fat interposition between the dura mater and spinous process of L5 was noted in 67 out of the 85 patients with spondylolysis (78.8%) and three of the patients without pars interarticularis fracture (3.2%). The difference was statistically significant (P<0.01). This sign has a specificity of 96.7%, sensitivity of 78.8%, positive predictive value of 95.7%, negative predictive value of 83.3% and accuracy of 88.2% for diagnosis of spondylolysis. Epidural fat interposition between the dura mater and spinous process may be a helpful sign for the diagnosis of spondylolysis on mid-sagittal MR imaging of the lumbar spine. (orig.)

Epidural fat interposition between dura mater and spinous process: a new sign for the diagnosis of spondylolysis on MR imaging of the lumbar spine

International Nuclear Information System (INIS)

Sherif, Hanan; Mahfouz, Ahmed-Emad

2004-01-01

The purpose of this study was to assess the diagnostic value of epidural fat interposition between the dura mater and spinous process of L5 as an indirect sign of spondylolysis on mid-sagittal MR imaging of the lumbar spine. Mid-sagittal T1-weighted MR images of the lumbar spine of 85 patients with spondylolysis and 93 patients without pars interarticularis fractures were randomized and evaluated by a masked reader. After a training sample of five cases, the reader was asked to note the presence or absence of epidural fat interposition between the dura mater and spinous process of L5 on the randomized images. The epidural fat interposition between the dura mater and spinous process of L5 was noted in 67 out of the 85 patients with spondylolysis (78.8%) and three of the patients without pars interarticularis fracture (3.2%). The difference was statistically significant (P<0.01). This sign has a specificity of 96.7%, sensitivity of 78.8%, positive predictive value of 95.7%, negative predictive value of 83.3% and accuracy of 88.2% for diagnosis of spondylolysis. Epidural fat interposition between the dura mater and spinous process may be a helpful sign for the diagnosis of spondylolysis on mid-sagittal MR imaging of the lumbar spine. (orig.)

In medias res

DEFF Research Database (Denmark)

Foote, Jonathan

2017-01-01

nor does he begin the Trojan War ab ovo (with the egg) but always he hurries to the action and snatches the listener in medias res (into the middle of things)      Horace, Ars Poetica 145–147 Good epic poets do not commence their tale from the beginning—ab ovo (with the egg)—as Horace states......, but rather descend in medias res (into the middle of things), a reference to the Illiad opening already many years into the Trojan War. Perhaps this sentiment of plunging into the middle of action was felt by researchers in 1976 when, upon the walls of the San Lorenzo New Sacristy in Florence, they uncovered...

Remotely sensed phenology for mapping biomes and vegetation functional types

CSIR Research Space (South Africa)

Wessels, Konrad J

2009-07-01

Full Text Available clearly captured in Fig. 3. The majority of the pixels in the Savanna have a start of growing season in late October, midposition in February and end in June (Fig. 3). In contrast, the winter rainfall Succulent Karoo have a start of growing season... initially split the biomes based on vegetation production and then by the seasonality of growth IV - 1035 (Fig. 4). The three arid biomes (Desert, Succulent and Nama Figure 3. Frequency histograms of the mean START, midposition (MID) and END date...

FIFE data analysis: Testing BIOME-BGC predictions for grasslands

Science.gov (United States)

Hunt, E. Raymond, Jr.

1994-01-01

The First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) was conducted in a 15 km by 15 km research area located 8 km south of Manhattan, Kansas. The site consists primarily of native tallgrass prairie mixed with gallery oak forests and croplands. The objectives of FIFE are to better understand the role of biology in controlling the interactions between the land and the atmosphere, and to determine the value of remotely sensed data for estimating climatological parameters. The goals of FIFE are twofold: the upscale integration of models, and algorithm development for satellite remote sensing. The specific objectives of the field campaigns carried out in 1987 and 1989 were the simultaneous acquisition of satellite, atmospheric, and surface data; and the understanding of the processes controlling surface energy and mass exchange. Collected data were used to study the dynamics of various ecosystem processes (photosynthesis, evaporation and transpiration, autotrophic and heterotrophic respiration, etc.). Modelling terrestrial ecosystems at scales larger than that of a homogeneous plot led to the development of simple, generalized models of biogeochemical cycles that can be accurately applied to different biomes through the use of remotely sensed data. A model was developed called BIOME-BGC (for BioGeochemical Cycles) from a coniferous forest ecosystem model, FOREST-BGC, where a biome is considered a combination of a life forms in a specified climate. A predominately C4-photosynthetic grassland is probably the most different from a coniferous forest possible, hence the FIFE site was an excellent study area for testing BIOME-BGC. The transition from an essentially one-dimensional calculation to three-dimensional, landscape scale simulations requires the introduction of such factors as meteorology, climatology, and geomorphology. By using remotely sensed geographic information data for important model inputs, process

RES: Regularized Stochastic BFGS Algorithm

Science.gov (United States)

Mokhtari, Aryan; Ribeiro, Alejandro

2014-12-01

RES, a regularized stochastic version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method is proposed to solve convex optimization problems with stochastic objectives. The use of stochastic gradient descent algorithms is widespread, but the number of iterations required to approximate optimal arguments can be prohibitive in high dimensional problems. Application of second order methods, on the other hand, is impracticable because computation of objective function Hessian inverses incurs excessive computational cost. BFGS modifies gradient descent by introducing a Hessian approximation matrix computed from finite gradient differences. RES utilizes stochastic gradients in lieu of deterministic gradients for both, the determination of descent directions and the approximation of the objective function's curvature. Since stochastic gradients can be computed at manageable computational cost RES is realizable and retains the convergence rate advantages of its deterministic counterparts. Convergence results show that lower and upper bounds on the Hessian egeinvalues of the sample functions are sufficient to guarantee convergence to optimal arguments. Numerical experiments showcase reductions in convergence time relative to stochastic gradient descent algorithms and non-regularized stochastic versions of BFGS. An application of RES to the implementation of support vector machines is developed.

The Biological Observation Matrix (BIOM) format or: how I learned to stop worrying and love the ome-ome.

Science.gov (United States)

McDonald, Daniel; Clemente, Jose C; Kuczynski, Justin; Rideout, Jai Ram; Stombaugh, Jesse; Wendel, Doug; Wilke, Andreas; Huse, Susan; Hufnagle, John; Meyer, Folker; Knight, Rob; Caporaso, J Gregory

2012-07-12

We present the Biological Observation Matrix (BIOM, pronounced "biome") format: a JSON-based file format for representing arbitrary observation by sample contingency tables with associated sample and observation metadata. As the number of categories of comparative omics data types (collectively, the "ome-ome") grows rapidly, a general format to represent and archive this data will facilitate the interoperability of existing bioinformatics tools and future meta-analyses. The BIOM file format is supported by an independent open-source software project (the biom-format project), which initially contains Python objects that support the use and manipulation of BIOM data in Python programs, and is intended to be an open development effort where developers can submit implementations of these objects in other programming languages. The BIOM file format and the biom-format project are steps toward reducing the "bioinformatics bottleneck" that is currently being experienced in diverse areas of biological sciences, and will help us move toward the next phase of comparative omics where basic science is translated into clinical and environmental applications. The BIOM file format is currently recognized as an Earth Microbiome Project Standard, and as a Candidate Standard by the Genomic Standards Consortium.

Constrained variability of modeled T:ET ratio across biomes

Science.gov (United States)

Fatichi, Simone; Pappas, Christoforos

2017-07-01

A large variability (35-90%) in the ratio of transpiration to total evapotranspiration (referred here as T:ET) across biomes or even at the global scale has been documented by a number of studies carried out with different methodologies. Previous empirical results also suggest that T:ET does not covary with mean precipitation and has a positive dependence on leaf area index (LAI). Here we use a mechanistic ecohydrological model, with a refined process-based description of evaporation from the soil surface, to investigate the variability of T:ET across biomes. Numerical results reveal a more constrained range and higher mean of T:ET (70 ± 9%, mean ± standard deviation) when compared to observation-based estimates. T:ET is confirmed to be independent from mean precipitation, while it is found to be correlated with LAI seasonally but uncorrelated across multiple sites. Larger LAI increases evaporation from interception but diminishes ground evaporation with the two effects largely compensating each other. These results offer mechanistic model-based evidence to the ongoing research about the patterns of T:ET and the factors influencing its magnitude across biomes.

Pollen-based biome reconstruction for southern Europe and Africa 18,000 yr BP

NARCIS (Netherlands)

Elenga, H; Peyron, O; Bonnefille, R; Jolly, D; Cheddadi, R; Guiot, J; Andrieu, [No Value; Bottema, S; Buchet, G; de Beaulieu, JL; Hamilton, AC; Maley, J; Marchant, R; Perez-Obiol, R; Reille, M; Riollet, G; Scott, L; Straka, H; Taylor, D; Van Campo, E; Vincens, A; Laarif, F; Jonson, H

Pollen data from 18,000 C-14 yr sp were compiled in order to reconstruct biome distributions at the last glacial maximum in southern Europe and Africa. Biome reconstructions were made using the objective biomization method applied to pollen counts using a complete list of dryland taxa wherever

Identification of biomes affected by marginal expansion of agricultural land use induced by increased crop consumption

DEFF Research Database (Denmark)

Kløverpris, Jesper Hedal

2009-01-01

to characterise these areas. The present study ascribes so-called biomes (natural potential vegetation) to the areas affected by agricultural expansion in order to provide a basis for assessing the environmental impacts from land use in the life cycle impact assessment (LCIA). The methodology builds...... on agricultural statistics and maps of global agricultural areas and the global distribution of biomes. The application of the method is illustrated with four examples. The results indicate that agricultural expansion on land suited for crop cultivation (cultivable land) typically affects forest biomes...... or potential grassland/steppe, whereas expansion on land suited for grazing but not for crop cultivation (grazable land) typically occurs on potential shrubland or a few other biomes depending on the region. Some uncertainty applies to the results but it is concluded that it is feasible to identify biomes...

Kes tegelikult lõid Res Publica? / Valeri Kalabugin

Index Scriptorium Estoniae

Kalabugin, Valeri

2005-01-01

Enne erakonnaks kuulutamist oli Res Publica Eesti iseseisvust ja demokraatiat taotlev ühendus, kuhu on kuulunud mitmed poliitika- ning ühiskonnategelased. Vt. samas: Ühendus Res Publica avaldus. Küsimustele vastavad Res Publica avalike suhete juht Riina Vändre, Riigikogu liige Mart Nutt, ajakirjanik Toomas Kümmel

Forest carbon emissions from cropland expansion in the Brazilian Cerrado biome

Science.gov (United States)

Noojipady, Praveen; Morton, C. Douglas; Macedo, N. Marcia; Victoria, C. Daniel; Huang, Chengquan; Gibbs, K. Holly; Edson Bolfe, L.

2017-02-01

Land use, land use change, and forestry accounted for two-thirds of Brazil’s greenhouse gas emissions profile in 2005. Amazon deforestation has declined by more than 80% over the past decade, yet Brazil’s forests extend beyond the Amazon biome. Rapid expansion of cropland in the neighboring Cerrado biome has the potential to undermine climate mitigation efforts if emissions from dry forest and woodland conversion negate some of the benefits of avoided Amazon deforestation. Here, we used satellite data on cropland expansion, forest cover, and vegetation carbon stocks to estimate annual gross forest carbon emissions from cropland expansion in the Cerrado biome. Nearly half of the Cerrado met Brazil’s definition of forest cover in 2000 (≥0.5 ha with ≥10% canopy cover). In areas of established crop production, conversion of both forest and non-forest Cerrado formations for cropland declined during 2003-2013. However, forest carbon emissions from cropland expansion increased over the past decade in Matopiba, a new frontier of agricultural production that includes portions of Maranhão, Tocantins, Piauí, and Bahia states. Gross carbon emissions from cropland expansion in the Cerrado averaged 16.28 Tg C yr-1 between 2003 and 2013, with forest-to-cropland conversion accounting for 29% of emissions. The fraction of forest carbon emissions from Matopiba was much higher; between 2010-2013, large-scale cropland conversion in Matopiba contributed 45% of total Cerrado forest carbon emissions. Carbon emissions from Cerrado-to-cropland transitions offset 5%-7% of the avoided emissions from reduced Amazon deforestation rates during 2011-2013. Comprehensive national estimates of forest carbon fluxes, including all biomes, are critical to detect cross-biome leakage within countries and achieve climate mitigation targets to reduce emissions from land use, land use change, and forestry.

Laser bonding with ICG-infused chitosan patches: preliminary experiences in suine dura mater and vocal folds

Science.gov (United States)

Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Pini, Roberto; Iacoangeli, Maurizio; Giannoni, Luca; Fortuna, Damiano; Di Cicco, Emiliano; Corbara, Sylwia; Dallari, Stefano

2014-05-01

Laser bonding is a promising minimally invasive approach, emerging as a valid alternative to conventional suturing techniques. It shows widely demonstrated advantages in wound treatment: immediate closuring effect, minimal inflammatory response and scar formation, reduced healing time. This laser based technique can overcome the difficulties in working through narrow surgical corridors (e.g. the modern "key-hole" surgery as well as the endoscopy setting) or in thin tissues that are impossible to treat with staples and/or stitches. We recently proposed the use of chitosan matrices, stained with conventional chromophores, to be used in laser bonding of vascular tissue. In this work we propose the same procedure to perform laser bonding of vocal folds and dura mater repair. Laser bonding of vocal folds is proposed to avoid the development of adhesions (synechiae), after conventional or CO2 laser surgery. Laser bonding application in neurosurgery is proposed for the treatment of dural defects being the Cerebro Spinal Fluid leaks still a major issue. Vocal folds and dura mater were harvested from 9-months old porks and used in the experimental sessions within 4 hours after sacrifice. In vocal folds treatment, an IdocyanineGreen-infused chitosan patch was applied onto the anterior commissure, while the dura mater was previously incised and then bonded. A diode laser emitting at 810 nm, equipped with a 600 μm diameter optical fiber was used to weld the patch onto the tissue, by delivering single laser spots to induce local patch/tissue adhesion. The result is an immediate adhesion of the patch to the tissue. Standard histology was performed, in order to study the induced photothermal effect at the bonding sites. This preliminary experimental activity shows the advantages of the proposed technique in respect to standard surgery: simplification of the procedure; decreased foreign-body reaction; reduced inflammatory response; reduced operating times and better handling in

Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

OpenAIRE

Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

1992-01-01

The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tend...

Mida ootame Res Publica poliitikutelt? / Andreas Kaju

Index Scriptorium Estoniae

Kaju, Andreas

2003-01-01

Res Publica Juventus on piirkondadele saadetud küsitlustega otsinud vastuseid mitmetele probleemidele. Eesmärk Res Publica poliitilise käitumise raamide määramine. Tabel: Juventuse küsimused piirkondadele

Consequences of biome depletion

International Nuclear Information System (INIS)

Salvucci, Emiliano

2013-01-01

The human microbiome is an integral part of the superorganism together with their host and they have co-evolved since the early days of the existence of the human species. The modification of the microbiome as a result changes in food and social habits of human beings throughout their life history has led to the emergence of many diseases. In contrast with the Darwinian view of nature of selfishness and competence, new holistic approaches are rising. Under these views, the reconstitution of the microbiome comes out as a fundamental therapy for emerging diseases related to biome depletion.

Structural characterization of vegetation in the fynbos biome

CSIR Research Space (South Africa)

Campbell, BM

1981-08-01

Full Text Available A proposed system for the standardization of descriptive terminology for structural characterization of vegetation in the Fynbos Biome is presented in tabular form. Specific applications of the system are described and illustrations of some...

Rahvaliit likvideerib Res Publica veeuputust / Janno Reiljan

Index Scriptorium Estoniae

Reiljan, Janno, 1951-2018

2005-01-01

Ilmunud ka: Molodjozh Estonii 1. august lk. 5. Selgitused Res Publica esimehe Taavi Veskimägi artiklile 25. juuli Postimehes "Pärast meid tulgu või veeuputus". Res Publica ja Rahvaliidu poliitika võrdlus

Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes.

Science.gov (United States)

García-Palacios, Pablo; Maestre, Fernando T; Kattge, Jens; Wall, Diana H

2013-08-01

Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesised litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~ 37%). [corrected]. However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models. © 2013 John Wiley & Sons Ltd/CNRS.

Federal Conservation Units in Brazil: The Situation of Biomes and Regions

Directory of Open Access Journals (Sweden)

Eduardo Pacca Luna Mattar

2018-03-01

Full Text Available ABSTRACT Federal conservation units (FCU are areas legally established by the government, in order to meet the needs of protection and sustainable exploitation of biodiversity. A way to ensure the efficiency of public management is to systematize data. Therefore, the present study grouped and analyzed public data about FCU. Brazil has 309 federal conservation units, which represent 9.06% of the national territory and 45305 residents households. The Northern Region covers 84.80% of these families and 79.20% of its area belongs to FCU. The Amazônia biome has 14.57% of its territory occupied by FCU; on the other hand, Pantanal has only 0.98% of its area protected. There is a higher concentration of public agents in the FCU of the Southeastern region and in the Mata Atlântica biome. The analysis of this information reveals significant differences between the biomes and the federation units, a fact that reflects the importance of the organization of public data.

La filatelia biomédica

Directory of Open Access Journals (Sweden)

Emilio J.A. Roldán

2011-02-01

Full Text Available La temática biomédica es un capítulo extendido de la filatelia o coleccionismo de sellos postales. Inaugura la temática la imagen de la diosa Hygeia, en un sello de la isla Nevis de 1861. Los primeros médicos retratados en una estampilla son tres constitucionalistas americanos, en un ejemplar de 1869, pero recién en 1937 aparecen médicos holandeses en reconocimiento específico de sus aportes a la salud. En la Argentina la primera estampilla que oficialmente se ocupa del tema es de 1944, en ayuda de las víctimas del terremoto de San Juan. Florentino Ameghino es el primer científico incluido en 1954, y en 1967 se edita un sello conmemorativo de la Dra. Cecilia Grierson. La filatelia argentina luego reconoce varios de nuestros científicos y médicos, congresos, universidades, campañas sanitarias, temas de odontología, farmacia, enfermería y otros, generando un amplio material filatélico en reconocimiento del valor social que la ciencia biomédica argentina ha logrado en el contexto propio e internacional. Posiblemente sea un científico, el Dr. Bernardo Houssay, uno de los argentinos más veces editado en distintos sellos postales de la filatelia mundial.

Two New Species and New Occurrences of Syneches Walker for Brazilian Biome of Caatinga (Diptera: Hybotidae: Hybotinae).

Science.gov (United States)

Soares, M M M; Ale-Rocha, R

2018-03-13

Syneches from Brazilian biome of Caatinga were studied, two new species are described, Syneches atratus sp. nov. and Syneches limeirai sp. nov., and three species, Syneches annulipes Bezzi, 1909, Syneches moraballi Smith, 1963, and Syneches rafaeli Ale-Rocha & Vieira, 2008, are recorded for the biome. An identification key for the species of Syneches from Caatinga biome is provided.

Rein Taagepera lahkub Res Publicast / Kristjan Roos

Index Scriptorium Estoniae

Roos, Kristjan, 1978-

2005-01-01

Res Publica asutaja Rein Taagepera, Jaan Einasto, Mare Taagepera ja Lauri Aaspõllu lahkuvad Res Publicast, kuna erakond on nende väitel muutunud paremtsentrist paremäärmuslikuks. Vt. samas: Erakonnad hoiavad uksed valla

BIOME: A browser-aware search and order system

Science.gov (United States)

Grubb, Jon W.; Jennings, Sarah V.; Yow, Teresa G.; Daughterty, Patricia F.

1996-01-01

The Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC), which is associated with NASA's Earth Observing System Data and Information System (EOSDIS), provides access to a large number of tabular and imagery datasets used in ecological and environmental research. Because of its large and diverse data holdings, the challenge for the ORNL DAAC is to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them. Therefore, the ORNL DAAC developed the Biogeochemical Information Ordering Management Environment (BIOME), a search and order system for the World Wide Web (WWW). The WWW provides a new vehicle that allows a wide range of users access to the data. This paper describes the specialized attributes incorporated into BIOME that allow researchers easy access to an otherwise bewildering array of data products.

BIOME: A scientific data archive search-and-order system using browser-aware, dynamic pages

Science.gov (United States)

Jennings, S. V.; Yow, T. G.; Ng, V. W.

1997-01-01

The Oak Ridge National Laboratory's (ORNL) Distributed Active Archive Center (DAAC) is a data archive and distribution center for the National Air and Space Administration's (NASA) Earth Observing System Data and Information System (EOSDIS). Both the Earth Observing System (EOS) and EOSDIS are components of NASA's contribution to the US Global Change Research Program through its Mission to Planet Earth Program. The ORNL DAAC provides access to data used in ecological and environmental research such as global change, global warming, and terrestrial ecology. Because of its large and diverse data holdings, the challenge for the ORNL DAAC is to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them. Therefore, the ORNL DAAC has developed the Biogeochemical Information Ordering Management Environment (BIOME), a customized search and order system for the World Wide Web (WWW). BIOME is a public system located at http://www-eosdis. ornl.gov/BIOME/biome.html.

Biome Is Where the Art Is

Science.gov (United States)

Gooden, Kelly

2005-01-01

The author is surprised every year when fifth-grade students react to the study of biomes as if they've never given any thought to the differences across parts of the world. Sure, they've all heard of the tropical rain forest and the desert, but it seems as though they think the rest of the world is just some undefined area with climate, animals,…

Res Publica esitas avalduse kaposse / Virkko Lepassalu

Index Scriptorium Estoniae

Lepassalu, Virkko, 1971-

2003-01-01

Kaposse jõudis Res Publica avaldus, milles palutakse uurida erakonda seadusvastaselt anonüümselt sponsoreerima kutsuva kirja tagamaid. Vt. ka Äripäev 19. veebruar lk. 6 "Kapo ei alustanud Res Publica avalduse peale kriminaalmenetlust"

Where do the treeless tundra areas of northern highlands fit in the global biome system: toward an ecologically natural subdivision of the tundra biome.

Science.gov (United States)

Virtanen, Risto; Oksanen, Lauri; Oksanen, Tarja; Cohen, Juval; Forbes, Bruce C; Johansen, Bernt; Käyhkö, Jukka; Olofsson, Johan; Pulliainen, Jouni; Tømmervik, Hans

2016-01-01

According to some treatises, arctic and alpine sub-biomes are ecologically similar, whereas others find them highly dissimilar. Most peculiarly, large areas of northern tundra highlands fall outside of the two recent subdivisions of the tundra biome. We seek an ecologically natural resolution to this long-standing and far-reaching problem. We studied broad-scale patterns in climate and vegetation along the gradient from Siberian tundra via northernmost Fennoscandia to the alpine habitats of European middle-latitude mountains, as well as explored those patterns within Fennoscandian tundra based on climate-vegetation patterns obtained from a fine-scale vegetation map. Our analyses reveal that ecologically meaningful January-February snow and thermal conditions differ between different types of tundra. High precipitation and mild winter temperatures prevail on middle-latitude mountains, low precipitation and usually cold winters prevail on high-latitude tundra, and Scandinavian mountains show intermediate conditions. Similarly, heath-like plant communities differ clearly between middle latitude mountains (alpine) and high-latitude tundra vegetation, including its altitudinal extension on Scandinavian mountains. Conversely, high abundance of snowbeds and large differences in the composition of dwarf shrub heaths distinguish the Scandinavian mountain tundra from its counterparts in Russia and the north Fennoscandian inland. The European tundra areas fall into three ecologically rather homogeneous categories: the arctic tundra, the oroarctic tundra of northern heights and mountains, and the genuinely alpine tundra of middle-latitude mountains. Attempts to divide the tundra into two sub-biomes have resulted in major discrepancies and confusions, as the oroarctic areas are included in the arctic tundra in some biogeographic maps and in the alpine tundra in others. Our analyses based on climate and vegetation criteria thus seem to resolve the long-standing biome

The Biological Observation Matrix (BIOM format or: how I learned to stop worrying and love the ome-ome

Directory of Open Access Journals (Sweden)

McDonald Daniel

2012-07-01

Full Text Available Abstract Background We present the Biological Observation Matrix (BIOM, pronounced “biome” format: a JSON-based file format for representing arbitrary observation by sample contingency tables with associated sample and observation metadata. As the number of categories of comparative omics data types (collectively, the “ome-ome” grows rapidly, a general format to represent and archive this data will facilitate the interoperability of existing bioinformatics tools and future meta-analyses. Findings The BIOM file format is supported by an independent open-source software project (the biom-format project, which initially contains Python objects that support the use and manipulation of BIOM data in Python programs, and is intended to be an open development effort where developers can submit implementations of these objects in other programming languages. Conclusions The BIOM file format and the biom-format project are steps toward reducing the “bioinformatics bottleneck” that is currently being experienced in diverse areas of biological sciences, and will help us move toward the next phase of comparative omics where basic science is translated into clinical and environmental applications. The BIOM file format is currently recognized as an Earth Microbiome Project Standard, and as a Candidate Standard by the Genomic Standards Consortium.

An intercomparison of biogenic emissions estimates from BEIS2 and BIOME: Reconciling the differences

Energy Technology Data Exchange (ETDEWEB)

Wilkinson, J.G. [Alpine Geophysics, Pittsburgh, PA (United States); Emigh, R.A. [Alpine Geophysics, Boulder, CO (United States); Pierce, T.E. [Atmospheric Characterization and Modeling Division/NOAA, Research Triangle Park, NC (United States)

1996-12-31

Biogenic emissions play a critical role in urban and regional air quality. For instance, biogenic emissions contribute upwards of 76% of the daily hydrocarbon emissions in the Atlanta, Georgia airshed. The Biogenic Emissions Inventory System-Version 2.0 (BEIS2) and the Biogenic Model for Emissions (BIOME) are two models that compute biogenic emissions estimates. BEIS2 is a FORTRAN-based system, and BIOME is an ARC/INFO{reg_sign} - and SAS{reg_sign}-based system. Although the technical formulations of the models are similar, the models produce different biogenic emissions estimates for what appear to be essentially the same inputs. The goals of our study are the following: (1) Determine why BIOME and BEIS2 produce different emissions estimates; (2) Attempt to understand the impacts that the differences have on the emissions estimates; (3) Reconcile the differences where possible; and (4) Present a framework for the use of BEIS2 and BIOME. In this study, we used the Coastal Oxidant Assessment for Southeast Texas (COAST) biogenics data which were supplied to us courtesy of the Texas Natural Resource Conservation Commission (TNRCC), and we extracted the BEIS2 data for the same domain. We compared the emissions estimates of the two models using their respective data sets BIOME Using TNRCC data and BEIS2 using BEIS2 data.

Afrique : ressources minières, environnement et gouvernance ...

International Development Research Centre (IDRC) Digital Library (Canada)

25 janv. 2011 ... ils regorgent de richesses inouïes », assure Bonnie Campbell, directrice du Groupe de recherche sur les activités minières en Afrique (GRAMA) et titulaire de la Chaire C.-A. Poissant de recherche sur la gouvernance et l'aide au développement, faisant référence aux ressources minières et pétrolières dont ...

Res Publica soolo rikkus tavasid / Kai Kalamees

Index Scriptorium Estoniae

Kalamees, Kai

2005-01-01

Riigikogu aseesimeheks valiti Res Publica liige Taavi Veskimägi, nüüd on Riigikogu juhatuses kaks ühe partei liiget. Riigikogu aseesimeheks tagasi valitud Toomas Vareki hinnangul näitab see samm nii Res Publica kogenematust kui ka Eesti poliitilise kultuuri kehva taset

The purifying bridge of Res Publica / Rein Taagepera

Index Scriptorium Estoniae

Taagepera, Rein, 1933-

2004-01-01

Res Publica edust Eesti poliitilisel maastikul. Autor käsitleb Res Publicat kui puhastava toimega ja silla funktsiooni täitvat parteid, mis üritab siduda tervikuks Keskerakonna ja Reformierakonna seisukohad

Evolutionary biology and anthropology suggest biome reconstitution as a necessary approach toward dealing with immune disorders.

Science.gov (United States)

Parker, William; Ollerton, Jeff

2013-01-01

Industrialized society currently faces a wide range of non-infectious, immune-related pandemics. These pandemics include a variety of autoimmune, inflammatory and allergic diseases that are often associated with common environmental triggers and with genetic predisposition, but that do not occur in developing societies. In this review, we briefly present the idea that these pandemics are due to a limited number of evolutionary mismatches, the most damaging being 'biome depletion'. This particular mismatch involves the loss of species from the ecosystem of the human body, the human biome, many of which have traditionally been classified as parasites, although some may actually be commensal or even mutualistic. This view, evolved from the 'hygiene hypothesis', encompasses a broad ecological and evolutionary perspective that considers host-symbiont relations as plastic, changing through ecological space and evolutionary time. Fortunately, this perspective provides a blueprint, termed 'biome reconstitution', for disease treatment and especially for disease prevention. Biome reconstitution includes the controlled and population-wide reintroduction (i.e. domestication) of selected species that have been all but eradicated from the human biome in industrialized society and holds great promise for the elimination of pandemics of allergic, inflammatory and autoimmune diseases.

Reimplementation of the Biome-BGC model to simulate successional change.

Science.gov (United States)

Bond-Lamberty, Ben; Gower, Stith T; Ahl, Douglas E; Thornton, Peter E

2005-04-01

Biogeochemical process models are increasingly employed to simulate current and future forest dynamics, but most simulate only a single canopy type. This limitation means that mixed stands, canopy succession and understory dynamics cannot be modeled, severe handicaps in many forests. The goals of this study were to develop a version of Biome-BGC that supported multiple, interacting vegetation types, and to assess its performance and limitations by comparing modeled results to published data from a 150-year boreal black spruce (Picea mariana (Mill.) BSP) chronosequence in northern Manitoba, Canada. Model data structures and logic were modified to support an arbitrary number of interacting vegetation types; an explicit height calculation was necessary to prioritize radiation and precipitation interception. Two vegetation types, evergreen needle-leaf and deciduous broadleaf, were modeled based on site-specific meteorological and physiological data. The new version of Biome-BGC reliably simulated observed changes in leaf area, net primary production and carbon stocks, and should be useful for modeling the dynamics of mixed-species stands and ecological succession. We discuss the strengths and limitations of Biome-BGC for this application, and note areas in which further work is necessary for reliable simulation of boreal biogeochemical cycling at a landscape scale.

Res Publica meelitab valla- ja linnajuhte / Henrik Roonemaa

Index Scriptorium Estoniae

Roonemaa, Henrik

2001-01-01

Valitsusliidu regionaalpoliitikas pettunud 30 omavalitsusjuhti on astunud ühenduse Res Publica liikmeks, lootes selle põhjal tekkiva partei abil kohaliku ja riigivõimu taas omavahel suhtlema panna. Vt. samas Res Publica liikmetest omavalitsusjuhid

Evolutionary history of a keystone pollinator parallels the biome occupancy of angiosperms in the Greater Cape Floristic Region.

Science.gov (United States)

de Jager, Marinus L; Ellis, Allan G

2017-02-01

The Greater Cape Floristic Region (GCFR) in South Africa has been extensively investigated for its phenomenal angiosperm diversity. A key emergent pattern is the occurrence of older plant lineages in the southern Fynbos biome and younger lineages in the northern Succulent Karoo biome. We know practically nothing, however, about the evolutionary history of the animals that pollinate this often highly-specialized flora. In this study, we explore the evolutionary history of an important GCFR fly pollinator, Megapalpus capensis, and ask whether it exhibits broadly congruent genetic structuring and timing of diversification to flowering plants within these biomes. We find that the oldest M. capensis lineages originated in Fynbos during the Miocene, while younger Succulent Karoo lineages diverged in the Pliocene and correspond to the proposed age of this recent biome. A strong signature of population expansion is also recovered for flies in this arid biome, consistent with recent colonization. Our first investigation into the evolutionary history of GCFR pollinators thus supports a recent origin of the SK biome, as inferred from angiosperm phylogenies, and suggests that plants and pollinators may have co-diverged within this remarkable area. Copyright © 2016 Elsevier Inc. All rights reserved.

RES-E-NEXT: Next Generation of RES-E Policy Instruments

Energy Technology Data Exchange (ETDEWEB)

Miller, M.; Bird, L.; Cochran, J.; Milligan, M.; Bazilian, M. [National Renewable Energy Laboratory, Golden, CO (United States); Denny, E.; Dillon, J.; Bialek, J.; O’Malley, M. [Ecar Limited (Ireland); Neuhoff, K. [DIW Berlin (Germany)

2013-07-04

The RES-E-NEXT study identifies policies that are required for the next phase of renewable energy support. The study analyses policy options that secure high shares of renewable electricity generation and adequate grid infrastructure, enhance flexibility and ensure an appropriate market design. Measures have limited costs or even save money, and policies can be gradually implemented.

Future changes in South American biomass distributions, biome distributions and plant trait spectra is dependent on applied atmospheric forcings.

Science.gov (United States)

Langan, Liam; Scheiter, Simon; Higgins, Steven

2017-04-01

It remains poorly understood why the position of the forest-savanna biome boundary, in a domain defined by precipitation and temperature, differs in South America, Africa and Australia. Process based Dynamic Global Vegetation Models (DGVMs) are a valuable tool to investigate the determinants of vegetation distributions, however, many DGVMs fail to predict the spatial distribution or indeed presence of the South American savanna biome. Evidence suggests fire plays a significant role in mediating forest-savanna biome boundaries, however, fire alone appear to be insufficient to predict these boundaries in South America. We hypothesize that interactions between precipitation, constraints on tree rooting depth and fire, affect the probability of savanna occurrence and the position of the savanna-forest boundary. We tested our hypotheses at tropical forest and savanna sites in Brazil and Venezuela using a novel DGVM, aDGVM2, which allows plant trait spectra, constrained by trade-offs between traits, to evolve in response to abiotic and biotic conditions. Plant hydraulics is represented by the cohesion-tension theory, this allowed us to explore how soil and plant hydraulics control biome distributions and plant traits. The resulting community trait distributions are emergent properties of model dynamics. We showed that across much of South America the biome state is not determined by climate alone. Interactions between tree rooting depth, fire and precipitation affected the probability of observing a given biome state and the emergent traits of plant communities. Simulations where plant rooting depth varied in space provided the best match to satellite derived biomass estimates and generated biome distributions that reproduced contemporary biome maps well. Future projections showed that biomass distributions, biome distributions and plant trait spectra will change, however, the magnitude of these changes are highly dependent on the applied atmospheric forcings.

Large-scale impact of climate change vs. land-use change on future biome shifts in Latin America.

Science.gov (United States)

Boit, Alice; Sakschewski, Boris; Boysen, Lena; Cano-Crespo, Ana; Clement, Jan; Garcia-Alaniz, Nashieli; Kok, Kasper; Kolb, Melanie; Langerwisch, Fanny; Rammig, Anja; Sachse, René; van Eupen, Michiel; von Bloh, Werner; Clara Zemp, Delphine; Thonicke, Kirsten

2016-11-01

Climate change and land-use change are two major drivers of biome shifts causing habitat and biodiversity loss. What is missing is a continental-scale future projection of the estimated relative impacts of both drivers on biome shifts over the course of this century. Here, we provide such a projection for the biodiverse region of Latin America under four socio-economic development scenarios. We find that across all scenarios 5-6% of the total area will undergo biome shifts that can be attributed to climate change until 2099. The relative impact of climate change on biome shifts may overtake land-use change even under an optimistic climate scenario, if land-use expansion is halted by the mid-century. We suggest that constraining land-use change and preserving the remaining natural vegetation early during this century creates opportunities to mitigate climate-change impacts during the second half of this century. Our results may guide the evaluation of socio-economic scenarios in terms of their potential for biome conservation under global change. © 2016 John Wiley & Sons Ltd.

Terrestrial ecosystem process model Biome-BGCMuSo v4.0: summary of improvements and new modeling possibilities

Science.gov (United States)

Hidy, Dóra; Barcza, Zoltán; Marjanović, Hrvoje; Zorana Ostrogović Sever, Maša; Dobor, Laura; Gelybó, Györgyi; Fodor, Nándor; Pintér, Krisztina; Churkina, Galina; Running, Steven; Thornton, Peter; Bellocchi, Gianni; Haszpra, László; Horváth, Ferenc; Suyker, Andrew; Nagy, Zoltán

2016-12-01

The process-based biogeochemical model Biome-BGC was enhanced to improve its ability to simulate carbon, nitrogen, and water cycles of various terrestrial ecosystems under contrasting management activities. Biome-BGC version 4.1.1 was used as a base model. Improvements included addition of new modules such as the multilayer soil module, implementation of processes related to soil moisture and nitrogen balance, soil-moisture-related plant senescence, and phenological development. Vegetation management modules with annually varying options were also implemented to simulate management practices of grasslands (mowing, grazing), croplands (ploughing, fertilizer application, planting, harvesting), and forests (thinning). New carbon and nitrogen pools have been defined to simulate yield and soft stem development of herbaceous ecosystems. The model version containing all developments is referred to as Biome-BGCMuSo (Biome-BGC with multilayer soil module; in this paper, Biome-BGCMuSo v4.0 is documented). Case studies on a managed forest, cropland, and grassland are presented to demonstrate the effect of model developments on the simulation of plant growth as well as on carbon and water balance.

Modeling Carbon and Water Budgets in the Lushi Basin with Biome-BGC

Institute of Scientific and Technical Information of China (English)

Dong Wenjuan; Qi Ye; Li Huimin; Zhou Dajie; Shi Duanhua; Sun Liying

2005-01-01

In this article, annual evapotranspiration (ET) and net primary productivity (NPP) of four types of vegetation were estimated for the Lushi basin,a subbasin of the Yellow River in China. These four vegetation types include: deciduous broadleaf forest,evergreen needle leaf forest, dwarf shrub and grass.Biome-BGC--a biogeochemical process model was used to calculate annual ET and NPP for each vegetation type in the study area from 1954 to 2000.Daily microclimate data of 47 years monitored by Lushi meteorological station was extrapolated to cover the basin using MT-CLIM, a mountain microclimate simulator. The output files of MTCLIM were used to feed Biome-BGC. We used average ecophysiological values of each type of vegetation supplied by Numerical Terradynamic Simulation Group (NTSG) in the University of Montana as input ecophysiological constants file.The estimates of daily NPP in early July and annual ET on these four biome groups were compared respectively with field measurements and other studies.Daily gross primary production (GPP) of evergreen needle leaf forest measurements were very dose to the output of Biome-BGC, but measurements of broadleaf forest and dwarf shrub were much smaller than the simulation result. Simulated annual ET and NPP had a significant correlation with precipitation,indicating precipitation is the major environmental factor affecting ET and NPP in the study area.Precipitation also is the key climatic factor for the interannual ET and NPP variations.

Core/shell cellulose-based microspheres for oral administration of Ketoprofen Lysinate.

Science.gov (United States)

Guarino, Vincenzo; Caputo, Tania; Calcagnile, Paola; Altobelli, Rosaria; Demitri, Christian; Ambrosio, Luigi

2018-01-26

Herein, we propose the fabrication of a new carrier with core/shell structure-inner core of cellulose acetate (CA) coated by a micrometric layer of chitosan (CS)-fabricated through an integrated process, which combines Electro Dynamic Atomization (EDA) and layer-by-layer (LbL) technique. We demonstrate that CA based microspheres possess a unique capability to relevantly retain the drugs-that is, Ketoprofen Lysinate (KL)-along the gastric tract, while providing a massive release along the intestine. CS shell slightly influences the morphology and water retention under different pH conditions, improving drug encapsulation without compromising drug release kinetics. In vitro studies in simulated gastric and intestine fluids (SGF, SIF) with physiological enzymes, show a moderate release of LSK during the first 2 h (ca. 20% at pH 2), followed by a sustained release during the next 6 h (ca. 80% at pH 7). The obtained results demonstrate that CA-based microspheres hold strong potential to be used as carriers for a delayed oral administration of anti-inflammatory drugs. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Structural analysis of fluorine-containing bioactive glass nanoparticles synthesized by sol-gel route assisted by ultrasound energy.

Science.gov (United States)

Lins, Carolina E C; Oliveira, Agda A R; Gonzalez, Ismael; Macedo, Waldemar A A; Pereira, Marivalda M

2018-01-01

In the last decades, studies about the specific effects of bioactive glass on remineralization of dentin were the focus of attention, due to their excellent regenerative properties in mineralized tissues. The incorporation of Fluorine in bioactive glass nanoparticles may result in the formation of fluorapatite (FAP), which is chemically more stable than hydroxyapatite or carbonated hydroxyapatite, and therefore is of interest for dental applications. The aim of this study was to synthesize and characterize a new system of Fluorine-containing bioactive glass nanoparticles (BGNPF). A sol-gel route assisted by ultrasound was used for the synthesis of BGNPF. The particles obtained were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD), dynamic light scattering (DLS), nitrogen adsorption, and X-ray photoelectron spectroscopy (XPS). SEM micrographs showed that the particles are quite uniform spherical nanostructures, occurring agglomeration or partial sinterization of the particulate system after heat treatment. XRD and XPS analysis results suggest the formation of fluorapatite crystals embedded within the matrix of the bioactive glass nanoparticles. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 360-366, 2018. © 2017 Wiley Periodicals, Inc.

Engineering specific chemical modification sites into a collagen-like protein from Streptococcus pyogenes.

Science.gov (United States)

Stoichevska, Violet; Peng, Yong Y; Vashi, Aditya V; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John A M

2017-03-01

Recombinant bacterial collagens provide a new opportunity for safe biomedical materials. They are readily expressed in Escherichia coli in good yield and can be readily purified by simple approaches. However, recombinant proteins are limited in that direct secondary modification during expression is generally not easily achieved. Thus, inclusion of unusual amino acids, cyclic peptides, sugars, lipids, and other complex functions generally needs to be achieved chemically after synthesis and extraction. In the present study, we have illustrated that bacterial collagens that have had their sequences modified to include cysteine residue(s), which are not normally present in bacterial collagen-like sequences, enable a range of specific chemical modification reactions to be produced. Various model reactions were shown to be effective for modifying the collagens. The ability to include alkyne (or azide) functions allows the extensive range of substitutions that are available via "click" chemistry to be accessed. When bifunctional reagents were used, some crosslinking occurred to give higher molecular weight polymeric proteins, but gels were not formed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 806-813, 2017. © 2016 Wiley Periodicals, Inc.

Electroactive polyurethane/siloxane derived from castor oil as a versatile cardiac patch, part I: Synthesis, characterization, and myoblast proliferation and differentiation.

Science.gov (United States)

Baheiraei, Nafiseh; Gharibi, Reza; Yeganeh, Hamid; Miragoli, Michele; Salvarani, Nicolò; Di Pasquale, Elisa; Condorelli, Gianluigi

2016-03-01

Tissue-engineered cardiac patch aims at regenerating an infarcted heart by improving cardiac function and providing mechanical support to the diseased myocardium. In order to take advantages of electroactivity, a new synthetic method was developed for the introduction of an electroactive oligoaniline into the backbone of prepared patches. For this purpose, a series of electroactive polyurethane/siloxane films containing aniline tetramer (AT) was prepared through sol-gel reaction of trimethoxysilane functional intermediate polyurethane prepolymers made from castor oil and poly(ethylene glycol). Physicochemical, mechanical, and electrical conductivity of samples were evaluated and the recorded results were correlated to their structural characteristics. The optimized films were proved to be biodegradable and have tensile properties suitable for cardiac patch application. The embedded AT moieties in the backbone of the prepared samples preserved their electroactivity with the electrical conductivity in the range of 10 -4 S/cm. The prepared films were compatible with proliferation of C2C12 and had potential for enhancing myotube formation even without external electrical stimulation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 775-787, 2016. © 2015 Wiley Periodicals, Inc.

Tailoring nanocrystalline diamond coated on titanium for osteoblast adhesion.

Science.gov (United States)

Pareta, Rajesh; Yang, Lei; Kothari, Abhishek; Sirinrath, Sirivisoot; Xiao, Xingcheng; Sheldon, Brian W; Webster, Thomas J

2010-10-01

Diamond coatings with superior chemical stability, antiwear, and cytocompatibility properties have been considered for lengthening the lifetime of metallic orthopedic implants for over a decade. In this study, an attempt to tailor the surface properties of diamond films on titanium to promote osteoblast (bone forming cell) adhesion was reported. The surface properties investigated here included the size of diamond surface features, topography, wettability, and surface chemistry, all of which were controlled during microwave plasma enhanced chemical-vapor-deposition (MPCVD) processes using CH4-Ar-H2 gas mixtures. The hardness and elastic modulus of the diamond films were also determined. H2 concentration in the plasma was altered to control the crystallinity, grain size, and topography of the diamond coatings, and specific plasma gases (O2 and NH3) were introduced to change the surface chemistry of the diamond coatings. To understand the impact of the altered surface properties on osteoblast responses, cell adhesion tests were performed on the various diamond-coated titanium. The results revealed that nanocrystalline diamond (grain sizes diamond and, thus, should be further studied for improving orthopedic applications. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

NH3/O2 mixed gas plasmas alter the interaction of blood components with stainless steel.

Science.gov (United States)

Chen, Meng; Zamora, Paul O; Peña, Louis; Som, Prantika; Osaki, Shigemasa

2003-12-01

Stainless steel treated with a mixed gas plasma of NH(3) plus O(2) had chemical and biologic characteristics distinct from untreated stainless steel or stainless steel treated with NH(3) or O(2) plasmas used separately. NH(3)/O(2) plasmas deposited nitrogen as both -CN (organic) and -NO (nitrate, nitrite)--materials not found on untreated stainless steel--and the contact angle changed from 44 degrees to 23 degrees. Treatment of stainless steel (and titanium) resulted in surfaces with enhanced resistance to platelet and leukocyte attachment. A gas plasma of N(2)O/O(2) also was found to reduce platelet and leukocyte attachment, suggesting that these properties may be common to surfaces coated with oxynitrites (nitrides). Upon subcutaneous implantation, no inflammation, hemolysis, or untoward thrombosis was noted in the tissue surrounding the wafers treated with the NH(3)/O(2) plasmas, although the cellular density was considerably reduced by 2 weeks after implant. Collectively, the results suggest that NH(3)/O(2) plasmas impart a unique character to stainless steel that may be useful in the construction of medical devices. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 994-1000, 2003

The functional response of bioactive titania-modified three-dimensional Ti-6Al-4V mesh structure toward providing a favorable pathway for intercellular communication and osteoincorporation.

Science.gov (United States)

Nune, K C; Misra, R D K; Li, S J; Hao, Y L; Zhang, W

2016-10-01

The objective of the study is to fundamentally elucidate the biological response of 3D printed mesh structures subjected to plasma electrolytic oxidation process through the study of osteoblast functions. The cellular activity of plasma electrolytic-oxidized mesh structure was explored in terms of cell-to-cell communication involving proliferation, synthesis of extracellular and intracellular proteins, and mineralization. Upon plasma electrolytic oxidation of the mesh structure, a thin layer of bioactive titania with pore size 1-3 µm was nucleated on the surface. The combination of microporous bioactive titania and interconnected porous architecture provided the desired pathway for supply of nutrients and oxygen to cells and tissue and a favorable osteogenic microenvironment for tissue on-growth and in-growth, in relation to the unmodified mesh structure. The formation of a confluent layer as envisaged via electron microscopy and quantitative assessment of the expression level of proteins (actin, vinculin, and fibronectin) point toward the determining role of surface-modified mesh structure in modulating osteoblasts functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2488-2501, 2016. © 2016 Wiley Periodicals, Inc.

Injectable dual redox responsive diselenide-containing poly(ethylene glycol) hydrogel.

Science.gov (United States)

Gong, Chu; Shan, Meng; Li, Bingqiang; Wu, Guolin

2017-09-01

An injectable dual redox responsive diselenide-containing poly(ethylene glycol) (PEG) hydrogel was successfully developed by combining the conceptions of injectable hydrogels and dual redox responsive diselenides. In the first step, four-armed PEG was modified with N-hydroxysuccinimide (NHS)-activated esters and thereafter, crosslinked by selenocystamine crosslinkers to form injectable hydrogels via the rapid reaction between NHS-activated esters and amino groups. The cross-sectional morphology, mechanical properties, and crosslinking modes of hydrogels were well characterized via scanning electron microscope (SEM), rheological measurements, and Fourier transform infrared spectra, respectively. In addition, the oxidation- and reduction-responsive degradation behaviors of hydrogels were observed and analyzed. The model drug, rhodamine B, was encapsulated in the hydrogel. The drug-loaded hydrogel exhibited a dual redox responsive release profile, which was consistent with the degradation experiments. The results of all experiments indicated that the formulated injectable dual redox responsive diselenide-containing PEG hydrogel can have potential applications in various biomedical fields such as drug delivery and stimuli-responsive drug release. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2451-2460, 2017. © 2017 Wiley Periodicals, Inc.

Effect of carrageenans alone and in combination with casein or lipopolysaccharide on human epithelial intestinal HT-29 cells.

Science.gov (United States)

Sokolova, E V; Kuz'mich, A S; Byankina, A O; Yermak, I M

2017-10-01

The research described here was focused on the effect on human intestinal epithelial cell monolayers of sulfated red algal polysaccharides (κ-, λ-, and κ/β-carrageenans) alone and in combination with casein or lipopolysaccharide (LPS). HT-29 cells were investigated under normal and stress conditions; stress was induced by exposure to ethanol. Cell viability was monitored with a real-time system. The change in binding properties of negatively sulfated red algal polysaccharides assessed by the measurement of free carrageenans in mixtures with casein or McCoy's 5 A culture medium by means of toluidine blue O. Low sulfate content and the presence of 3,6-anhydogalactose are prerequisites for the recovery of ethanol-exposed HT-29 cells by carrageenans. Analysis of carrageenan binding ability confirmed that casein and LPS should affect carrageenan activity. Whether the combined action of the mucin-containing layer and carrageenans or the action of carrageenans alone was responsible for enhanced cell viability under stress conditions induced by ethanol is a subject for further research. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2843-2850, 2017. © 2017 Wiley Periodicals, Inc.

Enhanced bioactivity and osseointegration of PEEK with accelerated neutral atom beam technology.

Science.gov (United States)

Khoury, Joseph; Maxwell, Melissa; Cherian, Raymond E; Bachand, James; Kurz, Arthur C; Walsh, Michael; Assad, Michel; Svrluga, Richard C

2017-04-01

Polyetheretherketone (PEEK) is growing in popularity for orthopedic, spinal, and trauma applications but has potential significant limitations in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent, but is inert and therefore does not integrate well with bone. Current efforts are focusing on increasing the bioactivity of PEEK with surface modifications to improve the bone-implant interface. We used a novel Accelerated Neutral Atom Beam (ANAB) technology to enhance the bioactivity of PEEK. Human osteoblast-like cells seeded on ANAB-treated PEEK result in significantly enhanced proliferation compared with control PEEK. Cells grown on ANAB-treated PEEK increase osteogenic expression of ALPL (1.98-fold, p PEEK implants resulted in enhanced bone-in-contact by 3.09-fold (p PEEK has the potential to enhance its bioactivity, leading to bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants. ANAB treatment, therefore, may significantly enhance the performance of PEEK medical implants and lead to improved clinical outcomes. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 531-543, 2017. © 2015 Wiley Periodicals, Inc.

Augmenting the bioactivity of polyetheretherketone using a novel accelerated neutral atom beam technique.

Science.gov (United States)

Ajami, S; Coathup, M J; Khoury, J; Blunn, G W

2017-08-01

Polyetheretherketone (PEEK) is an alternative to metallic implants in orthopedic applications; however, PEEK is bioinert and does not osteointegrate. In this study, an accelerated neutral atom beam technique (ANAB) was employed to improve the bioactivity of PEEK. The aim was to investigate the growth of human mesenchymal stem cells (hMSCs), human osteoblasts (hOB), and skin fibroblasts (BR3G) on PEEK and ANAB PEEK. The surface roughness and contact angle of PEEK and ANAB PEEK was measured. Cell metabolic activity, proliferation and alkaline phosphatase (ALP) was measured and cell attachment was determined by quantifying adhesion plaques with cells. ANAB treatment increased the surface hydrophilicity [91.74 ± 4.80° (PEEK) vs. 74.82 ± 2.70° (ANAB PEEK), p PEEK compared to PEEK (p PEEK surfaces. MSCs seeded on ANAB PEEK in the presence of osteogenic media, expressed increased levels of ALP compared to untreated PEEK (p PEEK. ANAB treatment may improve the osteointegration of PEEK implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1438-1446, 2017. © 2016 Wiley Periodicals, Inc.

Enhanced peripheral nerve regeneration through asymmetrically porous nerve guide conduit with nerve growth factor gradient.

Science.gov (United States)

Oh, Se Heang; Kang, Jun Goo; Kim, Tae Ho; Namgung, Uk; Song, Kyu Sang; Jeon, Byeong Hwa; Lee, Jin Ho

2018-01-01

In this study, we fabricated a nerve guide conduit (NGC) with nerve growth factor (NGF) gradient along the longitudinal direction by rolling a porous polycaprolactone membrane with NGF concentration gradient. The NGF immobilized on the membrane was continuously released for up to 35 days, and the released amount of the NGF from the membrane gradually increased from the proximal to distal NGF ends, which may allow a neurotrophic factor gradient in the tubular NGC for a sufficient period. From the in vitro cell culture experiment, it was observed that the PC12 cells sense the NGF concentration gradient on the membrane for the cell proliferation and differentiation. From the in vivo animal experiment using a long gap (20 mm) sciatic nerve defect model of rats, the NGC with NGF concentration gradient allowed more rapid nerve regeneration through the NGC than the NGC itself and NGC immobilized with uniformly distributed NGF. The NGC with NGF concentration gradient seems to be a promising strategy for the peripheral nerve regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 52-64, 2018. © 2017 Wiley Periodicals, Inc.

Engineering muscle cell alignment through 3D bioprinting.

Science.gov (United States)

Mozetic, Pamela; Giannitelli, Sara Maria; Gori, Manuele; Trombetta, Marcella; Rainer, Alberto

2017-09-01

Processing of hydrogels represents a main challenge for the prospective application of additive manufacturing (AM) to soft tissue engineering. Furthermore, direct manufacturing of tissue precursors with a cell density similar to native tissues has the potential to overcome the extensive in vitro culture required for conventional cell-seeded scaffolds seeking to fabricate constructs with tailored structural and functional properties. In this work, we present a simple AM methodology that exploits the thermoresponsive behavior of a block copolymer (Pluronic ® ) as a means to obtain good shape retention at physiological conditions and to induce cellular alignment. Pluronic/alginate blends have been investigated as a model system for the processing of C2C12 murine myoblast cell line. Interestingly, C2C12 cell model demonstrated cell alignment along the deposition direction, potentially representing a new avenue to tailor the resulting cell histoarchitecture during AM process. Furthermore, the fabricated constructs exhibited high cell viability, as well as a significantly improved expression of myogenic genes vs. conventional 2D cultures. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2582-2588, 2017. © 2017 Wiley Periodicals, Inc.

Chitosan nanofibers for transbuccal insulin delivery.

Science.gov (United States)

Lancina, Michael G; Shankar, Roopa Kanakatti; Yang, Hu

2017-05-01

In this work, they aimed at producing chitosan based nanofiber mats capable of delivering insulin via the buccal mucosa. Chitosan was electrospun into nanofibers using poly(ethylene oxide) (PEO) as a carrier molecule in various feed ratios. The mechanical properties and degradation kinetics of the fibers were measured. Insulin release rates were determined in vitro using an ELISA assay. The bioactivity of released insulin was measured in terms of Akt activation in pre-adipocytes. Insulin permeation across the buccal mucosa was measured in an ex-vivo porcine transbuccal model. Fiber morphology, mechanical properties, and in vitro stability were dependent on PEO feed ratio. Lower PEO content blends produced smaller diameter fibers with significantly faster insulin release kinetics. Insulin showed no reduction in bioactivity due to electrospinning. Buccal permeation of insulin facilitated by high chitosan content blends was significantly higher than that of free insulin. Taken together, the work demonstrates that chitosan-based nanofibers have the potential to serve as a transbuccal insulin delivery vehicle. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1252-1259, 2017. © 2017 Wiley Periodicals, Inc.

Feasibility of using bulk metallic glass for self-expandable stent applications.

Science.gov (United States)

Praveen Kumar, Gideon; Jafary-Zadeh, Mehdi; Tavakoli, Rouhollah; Cui, Fangsen

2017-10-01

Self-expandable stents are widely used to restore blood flow in a diseased artery segment by keeping the artery open after angioplasty. Despite the prevalent use of conventional crystalline metallic alloys, for example, nitinol, to construct self-expandable stents, new biomaterials such as bulk metallic glasses (BMGs) are being actively pursued to improve stent performance. Here, we conducted a series of analyses including finite element analysis and molecular dynamics simulations to investigate the feasibility of using a prototypical Zr-based BMG for self-expandable stent applications. We model stent crimping of several designs for different percutaneous applications. Our results indicate that BMG-based stents with diamond-shaped crowns suffer from severe localization of plastic deformation and abrupt failure during crimping. As a possible solution, we further illustrate that such abrupt failure could be avoided in BMG-based stents without diamond shape crowns. This work would open a new horizon for a quest toward exploiting superior mechanical and functional properties of metallic glasses to design future stents. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1874-1882, 2017. © 2016 Wiley Periodicals, Inc.

Development of biomimetic thermoplastic polyurethane/fibroin small-diameter vascular grafts via a novel electrospinning approach.

Science.gov (United States)

Yu, Emily; Mi, Hao-Yang; Zhang, Jue; Thomson, James A; Turng, Lih-Sheng

2018-04-01

A new electrospinning approach for fabricating vascular grafts with a layered, circumferentially aligned, and micro-wavy fibrous structure similar to natural elastic tissues has been developed. The customized electrospinning collector was able to generate wavy fibers using the dynamic "jump rope" collecting process, which also solved the sample removal problem for mandrel-type collectors. In this study, natural silk fibroin and synthetic thermoplastic polyurethane (TPU) were combined at different weight ratios to produce hybrid small-diameter vascular grafts. The purpose of combining these two materials was to leverage the bioactivity and tunable mechanical properties of these natural and synthetic materials. Results showed that the electrospun fiber morphology was highly influenced by the material compositions and solvents employed. All of the TPU/fibroin hybrid grafts had mechanical properties comparable to natural blood vessels. The circumferentially aligned and wavy biomimetic configuration provided the grafts with a sufficient toe region and the capacity for long-term usage under repeated dilatation and contraction. Cell culture tests with human endothelial cells (EC) also revealed high cell viability and good biocompatibility for these grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 985-996, 2018. © 2017 Wiley Periodicals, Inc.

Hemocompatibility and oxygenation performance of polysulfone membranes grafted with polyethylene glycol and heparin by plasma-induced surface modification.

Science.gov (United States)

Wang, Weiping; Zheng, Zhi; Huang, Xin; Fan, Wenling; Yu, Wenkui; Zhang, Zhibing; Li, Lei; Mao, Chun

2017-10-01

Polyethylene glycol (PEG) and heparin (Hep) were grafted onto polysulfone (PSF) membrane by plasma-induced surface modification to prepare PSF-PEG-Hep membranes used for artificial lung. The effects of plasma treatment parameters, including power, gas type, gas flow rate, and treatment time, were investigated, and different PEG chains were bonded covalently onto the surface in the postplasma grafting process. Membrane surfaces were characterized by water contact angle, PEG grafting degree, attenuated total reflectance-Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, X-ray photoelectron spectroscopy, critical water permeability pressure, and scanning electron microscopy. Protein adsorption, platelet adhesion, and coagulation tests showed significant improvement in the hemocompatibility of PSF-PEG-Hep membranes compared to pristine PSF membrane. Gas exchange tests through PSF-PEG6000-Hep membrane showed that when the flow rate of porcine blood reached 5.0 L/min, the permeation fluxes of O 2 and CO 2 reached 192.6 and 166.9 mL/min, respectively, which were close to the gas exchange capacity of a commercial membrane oxygenator. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1737-1746, 2017. © 2016 Wiley Periodicals, Inc.

Karoo biome: a preliminary sythesis. Part 1 - physical environment

CSIR Research Space (South Africa)

Cowling, RM

1986-01-01

Full Text Available . It is a multi-authored publication covering a wide range of topics. This first volume summarizes what is currently known on the physical environment of the biome; namely geology, soils, climate, hydrology, geohydrology and soil erosion. Other aspects...

Frontières sociales, frontières culturelles, frontières techniques

Directory of Open Access Journals (Sweden)

2010-12-01

Full Text Available Les sociétés démocratiques modernes ont basé leur unité sur l'égalité des chances et sur la mobilité sociale. Or, ce modèle d'intégration est fortement mis à l'épreuve aujourd'hui. Des discriminations structurelles viennent contredire le principe l'égalité de traitement. Des barrières difficilement franchissables, quel que soit le niveau, viennent contrecarrer la possibilité de promotion sociale. Un double phénomène est ainsi observable. D'une part, la société se fractionne en des espaces soc...

La filatelia biomédica

OpenAIRE

Emilio J.A. Roldán; Claudio Zuckerberg

2011-01-01

La temática biomédica es un capítulo extendido de la filatelia o coleccionismo de sellos postales. Inaugura la temática la imagen de la diosa Hygeia, en un sello de la isla Nevis de 1861. Los primeros médicos retratados en una estampilla son tres constitucionalistas americanos, en un ejemplar de 1869, pero recién en 1937 aparecen médicos holandeses en reconocimiento específico de sus aportes a la salud. En la Argentina la primera estampilla que oficialmente se ocupa del tema es de 1944, en ay...

Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: Biome-BGC is a computer program that estimates fluxes and storage of energy, water, carbon, and nitrogen for the vegetation and soil components of...

Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1

Data.gov (United States)

National Aeronautics and Space Administration — Biome-BGC is a computer program that estimates fluxes and storage of energy, water, carbon, and nitrogen for the vegetation and soil components of terrestrial...

Mechanical properties of the human lumbar dura mater Propriedades mecânicas da dura máter lombar humana

Directory of Open Access Journals (Sweden)

Edmundo Zarzur

1996-09-01

Full Text Available BACKGROUND AND OBJECTIVES: This study aimed to evaluate the transverse and longitudinal distensibility of the posterior human lumbar dura mater. Results are compared with previous literature on biomechanical property studies. Possible clinical implications were also examined. METHODS:Samples of human dural sac were obtained from autopsy studies in three adult male cadavers. Dural sac samples were sectioned longitudinally to measure transverse and longitudinal distensibility, thickness and circumference. RESULTS:It was recorded that the posterior lumbar dura mater was easily distensible only in the transverse direction. The longitudinal force required to distend and rupture the posterior lumbar dura mater samples is 3.5 to 6.7 times greater than the force to produce a transversal rupture. CONCLUSION: Depending on the local cerebrospinal fluid pressure, the documented easier transverse distensibility of the posterior lumbar dura mater may allow greater contact of the lumbar dural sac with the wall of the lumbar verterbral canal. This fact may affect the diffusion of solutions introduced into epidural space.Este estudo procura avaliar as distensibilidades transversal e longitudinal da dura máter lombar na sua porção posterior. Os resultados são comparados com os de outras investigações publicadas sobre as propriedades biomecânicas da dura máter. MÉTODOS: Amostras de dura máter foram obtidas de autópsias realizadas em três cadáveres de homens adultos. As amostras do saco dural foram secionadas longitudinalmente para permitir as seguintes medições: distensibilidade transversal e longitudinal, espessura da dura máter e circunferência do saco dural. RESULTADOS:Foi constatado que a dura máter lombar na sua porção posterior é facilmente distensível. Para distender e romper longitudinalmente esta mesma dura máter, necessita-se de 3,5 a 6,7 vezes mais força do que a necessária para a sua distensão e rompimento na dire

Res Publica pakub sponsoritele anonüümsust / Virkko Lepassalu

Index Scriptorium Estoniae

Lepassalu, Virkko, 1971-

2003-01-01

Mõnede tõenäoliselt Res Publica lähedaste ettevõtjate seas levib erakonna nimel rahapalumiskiri, mis lubab sponsorile anonüümsust. Vt. samas: Telefonikõne ettevõtja ja Res Publica aseesimehe Ken-Marti Vaheri vahel ; Teisedki on saanud rahaallikaid varjates ; Res Publica on loobunud reklaamibroneeringutest

Anthropogenic biomes: a key contribution to earth-system science

Science.gov (United States)

Lilian Alessa; F. Stuart Chapin

2008-01-01

Human activities now dominate most of the ice-free terrestrial surface. A recent article presents a classification and global map of human-influenced biomes of the world that provides a novel and potentially appropriate framework for projecting changes in earth-system dynamics.

Structural development and web service based sensitivity analysis of the Biome-BGC MuSo model

Science.gov (United States)

Hidy, Dóra; Balogh, János; Churkina, Galina; Haszpra, László; Horváth, Ferenc; Ittzés, Péter; Ittzés, Dóra; Ma, Shaoxiu; Nagy, Zoltán; Pintér, Krisztina; Barcza, Zoltán

2014-05-01

Studying the greenhouse gas exchange, mainly the carbon dioxide sink and source character of ecosystems is still a highly relevant research topic in biogeochemistry. During the past few years research focused on managed ecosystems, because human intervention has an important role in the formation of the land surface through agricultural management, land use change, and other practices. In spite of considerable developments current biogeochemical models still have uncertainties to adequately quantify greenhouse gas exchange processes of managed ecosystem. Therefore, it is an important task to develop and test process-based biogeochemical models. Biome-BGC is a widely used, popular biogeochemical model that simulates the storage and flux of water, carbon, and nitrogen between the ecosystem and the atmosphere, and within the components of the terrestrial ecosystems. Biome-BGC was originally developed by the Numerical Terradynamic Simulation Group (NTSG) of University of Montana (http://www.ntsg.umt.edu/project/biome-bgc), and several other researchers used and modified it in the past. Our research group developed Biome-BGC version 4.1.1 to improve essentially the ability of the model to simulate carbon and water cycle in real managed ecosystems. The modifications included structural improvements of the model (e.g., implementation of multilayer soil module and drought related plant senescence; improved model phenology). Beside these improvements management modules and annually varying options were introduced and implemented (simulate mowing, grazing, planting, harvest, ploughing, application of fertilizers, forest thinning). Dynamic (annually varying) whole plant mortality was also enabled in the model to support more realistic simulation of forest stand development and natural disturbances. In the most recent model version separate pools have been defined for fruit. The model version which contains every former and new development is referred as Biome-BGC MuSo (Biome

Parameterisation of Biome BGC to assess forest ecosystems in Africa

Science.gov (United States)

Gautam, Sishir; Pietsch, Stephan A.

2010-05-01

African forest ecosystems are an important environmental and economic resource. Several studies show that tropical forests are critical to society as economic, environmental and societal resources. Tropical forests are carbon dense and thus play a key role in climate change mitigation. Unfortunately, the response of tropical forests to environmental change is largely unknown owing to insufficient spatially extensive observations. Developing regions like Africa where records of forest management for long periods are unavailable the process-based ecosystem simulation model - BIOME BGC could be a suitable tool to explain forest ecosystem dynamics. This ecosystem simulation model uses descriptive input parameters to establish the physiology, biochemistry, structure, and allocation patterns within vegetation functional types, or biomes. Undocumented parameters for larger-resolution simulations are currently the major limitations to regional modelling in African forest ecosystems. This study was conducted to document input parameters for BIOME-BGC for major natural tropical forests in the Congo basin. Based on available literature and field measurements updated values for turnover and mortality, allometry, carbon to nitrogen ratios, allocation of plant material to labile, cellulose, and lignin pools, tree morphology and other relevant factors were assigned. Daily climate input data for the model applications were generated using the statistical weather generator MarkSim. The forest was inventoried at various sites and soil samples of corresponding stands across Gabon were collected. Carbon and nitrogen in the collected soil samples were determined from soil analysis. The observed tree volume, soil carbon and soil nitrogen were then compared with the simulated model outputs to evaluate the model performance. Furthermore, the simulation using Congo Basin specific parameters and generalised BIOME BGC parameters for tropical evergreen broadleaved tree species were also

Improved clonality detection in B-cell lymphoma using a semi-nested modification of the BIOMED-2 PCR assay for IGH rearrangement: A paraffin-embedded tissue study.

Science.gov (United States)

Sakamoto, Yuma; Masaki, Ayako; Aoyama, Satsuki; Han, Shusen; Saida, Kosuke; Fujii, Kana; Takino, Hisashi; Murase, Takayuki; Iida, Shinsuke; Inagaki, Hiroshi

2017-09-01

The BIOMED-2 PCR protocol for targeting the IGH gene is widely employed for detecting clonality in B-cell malignancies. Unfortunately, the detection of clonality with this method is not very sensitive when paraffin sections are used as a DNA source. To increase the sensitivity, we devised a semi-nested modification of a JH consensus primer. The clonality detection rates of three assays were compared: the standard BIOMED-2, BIOMED-2 assay followed by BIOMED-2 re-amplification, and BIOMED-2 assay followed by semi-nested BIOMED-2. We tested more than 100 cases using paraffin-embedded tissues of various B-cell lymphomas, and found that the clonality detection rates with the above three assays were 63.9%, 79.6%, and 88.0%, respectively. While BIOMED-2 re-amplification was significantly more sensitive than the standard BIOMED-2, the semi-nested BIOMED-2 was significantly more sensitive than both the standard BIOMED-2 and BIOMED-2 re-amplification. An increase in sensitivity was observed in all lymphoma subtypes examined. In conclusion, tumor clonality may be detected in nearly 90% of B-cell lymphoma cases with semi-nested BIOMED-2. This ancillary assay may be useful when the standard BIOMED-2 fails to detect clonality in histopathologically suspected B-cell lymphomas. © 2017 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

Hydrogen-induced structural transition in single layer ReS2

Science.gov (United States)

Yagmurcukardes, M.; Bacaksiz, C.; Senger, R. T.; Sahin, H.

2017-09-01

By performing density functional theory-based calculations, we investigate how structural, electronic and mechanical properties of single layer ReS2 can be tuned upon hydrogenation of its surfaces. It is found that a stable, fully hydrogenated structure can be obtained by formation of strong S-H bonds. The optimized atomic structure of ReS2H2 is considerably different than that of the monolayer ReS2 which has a distorted-1T phase. By performing phonon dispersion calculations, we also predict that the Re2-dimerized 1T structure (called 1T {{}\\text{R{{\\text{e}}2}}} ) of the ReS2H2 is dynamically stable. Unlike the bare ReS2 the 1T {{}\\text{R{{\\text{e}}2}}} -ReS2H2 structure which is formed by breaking the Re4 clusters into separated Re2 dimers, is an indirect-gap semiconductor. Furthermore, mechanical properties of the 1T {{}\\text{R{{\\text{e}}2}}} phase in terms of elastic constants, in-plane stiffness (C) and Poisson ratio (ν) are investigated. It is found that full hydrogenation not only enhances the flexibility of the single layer ReS2 crystal but also increases anisotropy of the elastic constants.

Intrinsic climate dependency of ecosystem light and water-use-efficiencies across Australian biomes

International Nuclear Information System (INIS)

Shi, Hao; Li, Longhui; Eamus, Derek; Cleverly, James; Huete, Alfredo; Yu, Qiang; Beringer, Jason; Van Gorsel, Eva; Hutley, Lindsay

2014-01-01

The sensitivity of ecosystem gross primary production (GPP) to availability of water and photosynthetically active radiation (PAR) differs among biomes. Here we investigated variations of ecosystem light-use-efficiency (eLUE: GPP/PAR) and water-use-efficiency (eWUE: GPP/evapotranspiration) among seven Australian eddy covariance sites with differing annual precipitation, species composition and temperature. Changes to both eLUE and eWUE were primarily correlated with atmospheric vapor pressure deficit (VPD) at multiple temporal scales across biomes, with minor additional correlations observed with soil moisture and temperature. The effects of leaf area index on eLUE and eWUE were also relatively weak compared to VPD, indicating an intrinsic dependency of eLUE and eWUE on climate. Additionally, eLUE and eWUE were statistically different for biomes between summer and winter, except eWUE for savannas and the grassland. These findings will improve our understanding of how light- and water-use traits in Australian ecosystems may respond to climate change. (letter)

Importance of soil-water to the Caatinga biome, Brazil

NARCIS (Netherlands)

Alves Rodrigues Pinheiro, Everton; Metselaar, Klaas; Jong van Lier, de Quirijn; Araújo, de José Carlos

2016-01-01

Northeastern Brazil is hydrologically characterized by recurrent droughts leading to a highly vulnerable natural water resource system. The region contains the Caatinga biome, covering an area of approximately 800000km². To increase insight in water balance components for this sparsely

Aura-biomes are present in the water layer above coral reef benthic macro-organisms.

Science.gov (United States)

Walsh, Kevin; Haggerty, J Matthew; Doane, Michael P; Hansen, John J; Morris, Megan M; Moreira, Ana Paula B; de Oliveira, Louisi; Leomil, Luciana; Garcia, Gizele D; Thompson, Fabiano; Dinsdale, Elizabeth A

2017-01-01

As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1) the coral Mussismilia braziliensis , (2) fleshy macroalgae ( Stypopodium , Dictota and Canistrocarpus ), (3) turf algae, and (4) the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific "aura-biome". The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria , Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

Res Publica lükkas tagasi Isamaaliidu ühinemisettepaneku / Mirko Ojakivi

Index Scriptorium Estoniae

Ojakivi, Mirko

2005-01-01

Kuigi Res Publica juhid lükkasid tagasi idee ühineda Isamaaliiduga, on Res Publica valmis koostööks nii Isamaaliidu kui ka kõigi teiste erakondadega. Res Publica parlamendifraktsiooni esimehe Marko Pomerantsi arvamus

Juhan Parts soovib Res Publica tagasi tippu viia / Toomas Sildam

Index Scriptorium Estoniae

Sildam, Toomas, 1961-

2004-01-01

Res Publica esimees peaminister Juhan Parts plaanib minna oma erakonnaga kohalikele valimistele ning uurib võimalusi paremerakondade ühinemiseks. Rakveres toimunud erakonna üldkogust. Lisad: Peaministri neli rasket hetke; Res Publica ministrid said parteilt toetuse. Vt. samas: Reformierakond kiitis Res Publicat hea koostöö eest; Parts: 191 vastuhäält on hea tulemus

Resúmenes Conferencias Magistrales

Directory of Open Access Journals (Sweden)

Editor Gabriel Vargas Arana

2015-12-01

Full Text Available En este artículo se pueden encontrar los resúmenes de las conferencias magistrales del III Congreso Latinoamericano de Plantas Medicinales, desarrollado del 12 al 14 de agosto de 2015 en la ciudad de Iquitos, Perú.

Resúmenes Presentaciones Orales

Directory of Open Access Journals (Sweden)

Editor Gabriel Vargas Arana

2015-12-01

Full Text Available En este artículo se pueden encontrar los resúmenes de las presentaciones orales del III Congreso Latinoamericano de Plantas Medicinales, desarrollado del 12 al 14 de agosto de 2015 en la ciudad de Iquitos, Perú.

Res Publicas käärib mäss / Hants Hint

Index Scriptorium Estoniae

Hint, Hants

2002-01-01

Res Publica eestseisuse liige ja Ida-Viru piirkonna esimees Hants Hint vastab küsimustele Res Publica ja Keskerakonna võimuliidu moodustamisega tekkinud skandaali, Res Publica esimehe Juhan Partsiga kohtumise kohta. Vt. samas: "Korbi toetajaid ootab hukkamõist"

Mechanical suitability of glycerol-preserved human dura mater for construction of prosthetic cardiac valves.

Science.gov (United States)

McGarvey, K A; Lee, J M; Boughner, D R

1984-03-01

We have examined the tensile viscoelastic properties of fresh and glycerol-preserved human dura mater, and correlated the results with structural information from the scanning electron microscope. The interwoven laminar structure of dura produces rather high flexural stiffness, while the crossed-fibrillar laminae produce planar mechanical isotropy. Glycerol storage shifts the stress-strain curve to lower strain, reduces stress relaxation and creep, and lowers the ultimate tensile strength and strain at fracture. These changes may be due to glyceraldehyde crosslinking, or to increased interfibrillar friction. The latter hypothesis suggests that glycerol storage may reduce the fatigue lifetime of the tissue.

Res Publica viskab Oleg Rebase välja

Index Scriptorium Estoniae

2006-01-01

Res Publica Tallinna piirkonna juhatus leidis, et Oleg Rebane läks Keskerakonna provokatsiooniga kaasa minnes vastuollu Res Publica põhimõtetega. Tallinna linnapea Jüri Ratase suhtes algatatud umbusaldushääletuse põhjustest. Sven Sester vastab küsimusele, mis seotud Oleg Rebase ja Tõnis Bittmani juhtumiga

Synergistic impacts of deforestation, climate change and fire on the future biomes distribution in Amazonia

Science.gov (United States)

Sampaio, G.; Cardoso, M. F.; Nobre, C. A.; Salazar, L. F.

2013-05-01

to important impacts that add considerably to the vulnerability of tropical forest ecosystems in the study region. REFERENCES Cardoso, M. F. ; Nobre, C. A. ; Sampaio, G. ; Hirota, M. ; Valeriano, D. ; Câmara, G. Long-term potential for tropical-forest degradation due to deforestation and fires in the Brazilian Amazon. Biologia (Bratislava), v. 64, p. 433-437, 2009. Malhi Y, et al. (2008) Climate change, deforestation, and the fate of the Amazon. Science 319:169-172. Oyama, M.D. and C.A. Nobre (2004), A simple potencial vegetation model for coupling with the Simple Biosphere Model (SIB). Revista Brasileira de Meteorologia, v. 19, n. 2, p. 203-216, 2004. Salazar, L. F., C. A. Nobre, and M. D. Oyama (2007), Climate change consequences on the biome distribution in tropical South America, Geophys. Res. Lett., 34, L09708, doi:10.1029/2007GL029695 Sampaio, G., C. A. Nobre, M. H. Costa, P. Satyamurty, B. S. Soares-Filho and, M. Cardoso (2007), Regional climate change over eastern Amazonia caused by pasture and soybean cropland expansion. Geophys. Res. Lett., 34, L17709, doi:10.1029/2007GL030612.

„Když všichni spustějí, je Vám to strašný rámus.“ Dvořákova duchovní kantáta Stabat Mater.

Czech Academy of Sciences Publication Activity Database

Kachlík, Jan

2017-01-01

Roč. 4, č. 3 (2017) ISSN 2533-6940 Institutional support: RVO:68378076 Keywords : Antonín Dvořák * Stabat Mater * performance history Subject RIV: AL - Art, Architecture, Cultural Heritage OBOR OECD: Performing arts studies (Musicology, Theater science, Dramaturgy) https://magazin.ceskafilharmonie.cz/kdyz-vsichni-spusteji-je-vam-to-strasny-ramus-dvorakova-duchovni-kantata-stabat-mater/

Remote Sensing of the Urban Heat Island Effect Across Biomes in the Continental USA

Science.gov (United States)

Imhoff, Marc L.; Zhang, Ping; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the Landsat TM-based NLCD 2001 dataset and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined for each urban area emanating outward from the urban core to the nonurban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling is further constrained by biome and elevation to insure objective intercomparisons between zones and between cities in different biomes permitting the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban-rural temperature difference) the largest (8 C average) observed for cities built in biomes dominated by temperate broadleaf and mixed forest. For all cities combined, ISA is the primary driver for increase in temperature explaining 70% of the total variance in LST. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9 C, except for urban areas in biomes with arid and semiarid climates. The average amplitude of the UHI is remarkably asymmetric with a 4.3 C temperature difference in summer and only 1.3 C in winter. In desert environments, the LST's response to ISA presents an uncharacteristic "U-shaped" horizontal gradient decreasing from the urban core to the outskirts of the city and then increasing again in the suburban to the rural zones. UHI's calculated for these cities point to a possible heat sink effect. These observational results show that the urban heat island amplitude both increases with city size and is seasonally

Parts ei soovi Res Publica esimehe ametit / Tuuli Koch

Index Scriptorium Estoniae

Koch, Tuuli

2005-01-01

Kõige tõenäolisem kandidaat Res Publica juhi kohale on Taavi Veskimägi, aseesimeesteks kandideerivad Marko Mihkelson ja Henn Pärn. Res Publica fraktsiooni koosolekul leidis Mihhail Lotman, et erakond võiks olla feminiinsem

Diagnóstico dos resíduos sólidos do setor agrossilvopastoril : resíduos sólidos inorgânicos

OpenAIRE

Rosseto, Renato

2013-01-01

Este trabalho buscou realizar o diagnóstico preliminar dos resíduos sólidos inorgânicos gerados no setor agrossilvopastoril, especialmente nos segmentos de agrotóxicos, fertilizantes, insumos farmacêuticos veterinários, além dos resíduos sólidos domésticos (RSDs) rurais Os assuntos foram separados em seções. De forma geral, a ausência de informações oficiais sistematizadas seguiu como a principal dificuldade em realizar o diagnóstico dos resíduos sólidos inorgânicos presentes no setor agrossi...

Mater Nostra: The Anti-blasphemy Message of the Feminist Punk-Prayer

Directory of Open Access Journals (Sweden)

Elena Ivanovna Volkova

2014-12-01

Full Text Available In this essay I develop a blasphemy counter-discourse arguing that it was ecclesial and state authorities who committed blasphemies, which were condemned by Pussy Riot’s punk-prayer. Thus, the performance in this respect may be interpreted as an anti-blasphemy protest. The blasphemy list includes the collaboration of the church with the authoritarian state, known as heresy of Sergianism; Caesar and Temple idolatry, blasphemy against the Holy Spirit, Virgin Mary and Folly for Christ’s sake. The punk-prayer may be interpreted as a feminine version of the Lord’s Prayer – Mater Nostra. Several corporeal narratives in the background – women’s dress code and rape debates, Virgin Mary’s belt, and its alleged miraculous ability to help women to deliver a baby – may be seen as allegories of feminist vs. patriarchal opposition in Russian religious and political culture.

Large-scale impact of climate change vs. land-use change on future biome shifts in Latin America

NARCIS (Netherlands)

Boit, Alice; Sakschewski, Boris; Boysen, Lena; Cano-Crespo, Ana; Clement, Jan; Garcia-alaniz, Nashieli; Kok, Kasper; Kolb, Melanie; Langerwisch, Fanny; Rammig, Anja; Sachse, René; Eupen, van Michiel; Bloh, von Werner; Clara Zemp, Delphine; Thonicke, Kirsten

2016-01-01

Climate change and land-use change are two major drivers of biome shifts causing habitat and biodiversity loss. What is missing is a continental-scale future projection of the estimated relative impacts of both drivers on biome shifts over the course of this century. Here, we provide such a

Estimating 40 years of nitrogen deposition in global biomes using the SCIAMACHY NO2 column

Science.gov (United States)

Lu, Xuehe; Zhang, Xiuying; Liu, Jinxun; Jin, Jiaxin

2016-01-01

Owing to human activity, global nitrogen (N) cycles have been altered. In the past 100 years, global N deposition has increased. Currently, the monitoring and estimating of N deposition and the evaluation of its effects on global carbon budgets are the focus of many researchers. NO2 columns retrieved by space-borne sensors provide us with a new way of exploring global N cycles and these have the ability to estimate N deposition. However, the time range limitation of NO2 columns makes the estimation of long timescale N deposition difficult. In this study we used ground-based NOx emission data to expand the density of NO2columns, and 40 years of N deposition (1970–2009) was inverted using the multivariate linear model with expanded NO2 columns. The dynamic of N deposition was examined in both global and biome scales. The results show that the average N deposition was 0.34 g N m–2 year–1 in the 2000s, which was an increase of 38.4% compared with the 1970s’. The total N deposition in different biomes is unbalanced. N deposition is only 38.0% of the global total in forest biomes; this is made up of 25.9%, 11.3, and 0.7% in tropical, temperate, and boreal forests, respectively. As N-limited biomes, there was little increase of N deposition in boreal forests. However, N deposition has increased by a total of 59.6% in tropical forests and croplands, which are N-rich biomes. Such characteristics may influence the effects on global carbon budgets.

Ecological consequences of the expansion of N2-fixing plants in cold biomes

Science.gov (United States)

Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D.; Reed, Sasha C.; Sigurdsson, Bjarni D.; Körner, Christian

2014-01-01

Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including increased N losses through nitrate leaching and emissions of the powerful greenhouse gas nitrous oxide (N2O). Here, we used literature review and case study approaches to assess the evidence for similar transformations in cold-climate ecosystems of the boreal, subarctic and upper montane-temperate life zones. Our assessment focuses on the plant genera Lupinus and Alnus, which have become invasive largely as a consequence of deliberate introductions and/or reduced land management. These cold biomes are commonly located in remote areas with low anthropogenic N inputs, and the environmental impacts of N2-fixer invasion appear to be as severe as those from anthropogenic N deposition in highly N polluted areas. Hence, inputs of N from N2 fixation can affect ecosystems as dramatically or even more strongly than N inputs from atmospheric deposition, and biomes in cold climates represent no exception with regard to the risk of being invaded by N2-fixing species. In particular, the cold biomes studied here show both a strong potential to be transformed by N2-fixing plants and a rapid subsequent saturation in the ecosystem’s capacity to retain N. Therefore, analogous to increases in N deposition, N2-fixing plant invasions must be deemed significant threats to biodiversity and to environmental quality.

BioMagResBank.

NARCIS (Netherlands)

Ulrich, E.L.; Akutsu, H.; Doreleijers, J.; Harano, Y.; Ioannidis, Y.E.; Lin, J.; Livny, M.; Mading, S.; Maziuk, D.; Miller, Z.; Nakatani, E.; Schulte, C.F.; Tolmie, D.E.; Wenger, R.K.; Yao, H.; Markley, J.L.

2008-01-01

The BioMagResBank (BMRB: www.bmrb.wisc.edu) is a repository for experimental and derived data gathered from nuclear magnetic resonance (NMR) spectroscopic studies of biological molecules. BMRB is a partner in the Worldwide Protein Data Bank (wwPDB). The BMRB archive consists of four main data

Hantavirus pulmonary syndrome and rodent reservoirs in the savanna-like biome of Brazil's southeastern region.

Science.gov (United States)

Limongi, J E; Oliveira, R C; Guterres, A; Costa Neto, S F; Fernandes, J; Vicente, L H B; Coelho, M G; Ramos, V N; Ferreira, M S; Bonvicino, C R; D'Andrea, P S; Lemos, E R S

2016-04-01

This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT-PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50-83·7%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

Investigación biomédica, intereses económicos y divulgación periodística

Directory of Open Access Journals (Sweden)

Roberto Germán Zurriaráin

2017-01-01

Full Text Available Este artículo pretende afirmar que toda investigación, especialmente la biomédica, para que sea precisamente tal, tiene que poseer una dimensión ética. Y goza de esta dimensión siempre y cuando vaya en beneficio del propio ser humano. Sin ella no se puede hablar de progreso en la investigación biomédica. Luego, solamente se puede denominar “progreso” si hablamos de una investigación que vaya en beneficio de cada uno de los seres humanos. Así es, la investigación biomédica se tiene que traducir en un avanzar del ser humano en humanidad. Pero desgracia- damente muchas veces no ocurre esto. Se llama investigación biomédica a todo, independien- temente de que posea o no una dimensión ética, considerada esta como una instancia exterior. Esta dimensión, insertada en la propia investigación biomédica, es sustituida por otros intere- ses, sobre todo de carácter económico, especialmente en reproducción humana artificial. Así también, los medios de comunicación social hacen eco de este tipo de estudios en biomedicina. Pero muchas veces los medios buscan más las emociones del espectador que su responsabilidad por transmitir noticias con rigor y veracidad.

Res Publica kärbiks võimuorganite koosseise / Argo Ideon

Index Scriptorium Estoniae

Ideon, Argo, 1966-

2002-01-01

Res Publica taotleb Riigikogu kärpimist 61 liikmeni, lubab kahandada kohalike volikogude koosseise, Tallinna abilinnapeade arvu ja kaotada portfellita ministrite kohad. Vt. samas: Res Publica valimisnimekiri Tallinnas

Tumefactive immunoglobulin G4-related disease involving the dura mater: A case report and literature review

International Nuclear Information System (INIS)

Lee, Jeong Hoon; Lee, Ji Hoon; Ko, Yong; Paik, Seoung Sam; Lee, Young Jun; Park, Dong Woo

2015-01-01

Immunoglobulin G4 (IgG4)-related disease is a well-known disorder characterized by an inflammatory reaction with an increase in the number of IgG4-positive plasma cells associated with sclerosis. IgG4-related disease often affects the dura mater with a pattern of diffuse thickening when the central nervous system is involved. However, some nodular dural thickening requires discrimination from tumors because of obviously different treatment options. We report of a case of IgG4-related disease with tumefactive dural involvement

Accurately evaluation Young's modulus of polymers through nanoindentations: a phenomenological correction factor to the Oliver and Pharr procedure

NARCIS (Netherlands)

Tranchida, D.; Piccarolo, S.; Loos, J.; Alexeev, A.A.

2006-01-01

The Oliver and Pharr [J. Mater. Res. 7, 1564 (1992)] procedure is a widely used tool to analyze nanoindentation force curves obtained on metals or ceramics. Its application to polymers is, however, difficult, as Young's moduli are commonly overestimated mainly because of viscoelastic effects and

Relaxor type perovskites: Primary candidates of nano-polar regions

Indian Academy of Sciences (India)

Unknown

between Pb and O ions. Kleeman et al5 ... sputtering,13 sol–gel14 etc. In the present work ..... Hence the barium-based non lead relaxor materials have been of ..... Kingon A I, Streiffer, Basceri C and Summerfelt S R 1996 Mater. Res. Soc. Bull.

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

Science.gov (United States)

van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

2008-12-01

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

Comment rendre les villes plus sûres

International Development Research Centre (IDRC) Digital Library (Canada)

qui travaillent à l'initiative Villes sûres et inclusives font la lumière sur ce qui fonctionne – et ne fonctionne pas – pour rendre les villes plus sûres. Le présent compte rendu comporte certains enseignements tirés de leur travail, ainsi que les lacunes dans les connaissances et les domaines où il faut poursuivre la recherche.

Pollen-based biome reconstructions for Colombia at 3000, 6000, 15 000 and 18 000 14C yr ago : Late Quaternary tropical vegetation dynamics

NARCIS (Netherlands)

Marchant, R.; Behling, H.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Schreve-Brinkman, E.; Geel, van B.; Hammen, van der T.; Reenen, van G.

2002-01-01

Colombian biomes are reconstructed at 45 sites from the modern period extending to the Last Glacial Maximum (LGM). The basis for our reconstruction is pollen data assigned to plant functional types and biomes at six 3000-yr intervals. A reconstruction of modern biomes is used to check the treatment

Temporal Changes in Coupled Vegetation Phenology and Productivity are Biome-Specific in the Northern Hemisphere

Directory of Open Access Journals (Sweden)

Lanhui Wang

2017-12-01

Full Text Available Global warming has greatly stimulated vegetation growth through both extending the growing season and promoting photosynthesis in the Northern Hemisphere (NH. Analyzing the combined dynamics of such trends can potentially improve our current understanding on changes in vegetation functioning and the complex relationship between anthropogenic and climatic drivers. This study aims to analyze the relationships (long-term trends and correlations of length of vegetation growing season (LOS and vegetation productivity assessed by the growing season NDVI integral (GSI in the NH (>30°N to study any dependency of major biomes that are characterized by different imprint from anthropogenic influence. Spatial patterns of converging/diverging trends in LOS and GSI and temporal changes in the coupling between LOS and GSI are analyzed for major biomes at hemispheric and continental scales from the third generation Global Inventory Monitoring and Modeling Studies (GIMMS Normalized Difference Vegetation Index (NDVI dataset for a 32-year period (1982–2013. A quarter area of the NH is covered by converging trends (consistent significant trends in LOS and GSI, whereas diverging trends (opposing significant trends in LOS and GSI cover about 6% of the region. Diverging trends are observed mainly in high latitudes and arid/semi-arid areas of non-forest biomes (shrublands, savannas, and grasslands, whereas forest biomes and croplands are primarily characterized by converging trends. The study shows spatially-distinct and biome-specific patterns between the continental land masses of Eurasia (EA and North America (NA. Finally, areas of high positive correlation between LOS and GSI showed to increase during the period of analysis, with areas of significant positive trends in correlation being more widespread in NA as compared to EA. The temporal changes in the coupled vegetation phenology and productivity suggest complex relationships and interactions that are induced

Res Publica andis kolmele poliitikule fiktiivse elukoha / Kärt Karpa

Index Scriptorium Estoniae

Karpa, Kärt, 1973-

2002-01-01

Väidetavalt lasi Res Publica enne kohalikke valimisi ühte Pirita eramajja sisse registreerida Jaanus Rahumäe ja veel kaks Res Publica liiget, et nad saaksid kandideerida Tallinna volikogusse ja Pirita halduskogusse

Res Publica ladvikus hõõgub võimutüli / Tuuli Koch

Index Scriptorium Estoniae

Koch, Tuuli

2006-01-01

22. aprillil kogunenud Res Publica volikogu toetas 60 poolthäälega ühe vastu Res Publica ja Isamaaliidu ühinemist. Tõnis Palts teatas volikogul esinedes, et Taavi Veskimägi ei sobi Res Publica poolseks läbirääkimiste juhiks

Res Publica kõrvaldas mässaja / Kristjan Roos

Index Scriptorium Estoniae

Roos, Kristjan, 1978-

2005-01-01

Tallinna linnavolikogu Res Publica fraktsiooni juhi kohalt, Res Publica Tallinna piirkonna juhatusest ja erakonna eestseisusest end taandanud Toomas Tautsi sõnul esitati talle erakonna eestseisuses mitmeid süüdistusi, mis kokkuvõtvalt olid etteheited tema vastuseisule võimalikule koalitsioonile Keskerakonnaga. Lisa: Abilinnapeadeks saavad Promm, Reivik ja Pevkur

South African Red Data Book: Plants - fynbos and Karoo biomes

CSIR Research Space (South Africa)

Hall, AV

1985-01-01

Full Text Available In this report a list is given of 1 808 rare, threatened and recently extinct plants in the fynbos and karoo biomes in the Cape Province of South Africa. The area covers the south-western and southern Cape, Namaqualand and the Karoo. Following...

Climate control of terrestrial carbon exchange across biomes and continents

Czech Academy of Sciences Publication Activity Database

Yi, C.; Ricciuto, D.; Marek, Michal V.

2010-01-01

Roč. 5, č. 3 (2010), s. 034007 ISSN 1748-9326 Institutional research plan: CEZ:AV0Z60870520 Keywords : NEE * climate control * terrestrial carbon sequestration * temperature * dryness * eddy flux * biomes * photosynthesis * respiration * global carbon cycle Subject RIV: EH - Ecology, Behaviour Impact factor: 3.049, year: 2010

Teine Res Musica ilmunud / Jaan Ross

Index Scriptorium Estoniae

Ross, Jaan, 1957-

2010-01-01

Artiklikogumikust: Res musica [2] : Eesti Muusikateaduse Seltsi ja Eesti Muusika- ja Teatriakadeemia muusikateaduse osakonna aastaraamat / peatoimetaja Urve Lippus. Tallinn : Eesti Muusika- ja Teatriakadeemia, 2010

Ticks parasitizing bats (Mammalia: Chiroptera) in the Caatinga Biome, Brazil.

Science.gov (United States)

Luz, Hermes Ribeiro; Muñoz-Leal, Sebastián; Almeida, Juliana Cardoso de; Faccini, João Luiz Horacio; Labruna, Marcelo Bahia

2016-01-01

In this paper, the authors report ticks parasitizing bats from the Serra das Almas Natural Reserve (RPPN) located in the municipality of Crateús, state of Ceará, in the semiarid Caatinga biome of northeastern Brazil. The study was carried out during nine nights in the dry season (July 2012) and 10 nights in the rainy season (February 2013). Only bats of the Phyllostomidae and Mormoopidae families were parasitized by ticks. The species Artibeus planirostris and Carolia perspicillata were the most parasitized. A total of 409 larvae were collected and classified into three genera: Antricola (n = 1), Nothoaspis (n = 1) and Ornithodoros (n = 407). Four species were morphologically identified as Nothoaspis amazoniensis, Ornithodoros cavernicolous, Ornithodoros fonsecai, Ornithodoros hasei, and Ornithodoros marinkellei. Ornithodoros hasei was the most common tick associated with bats in the current study. The present study expand the distributional ranges of at least three soft ticks into the Caatinga biome, and highlight an unexpected richness of argasid ticks inhabiting this arid ecosystem.

Impacts of land-use and land-cover change on stream hydrochemistry in the Cerrado and Amazon biomes.

Science.gov (United States)

Nóbrega, Rodolfo L B; Guzha, Alphonce C; Lamparter, Gabriele; Amorim, Ricardo S S; Couto, Eduardo G; Hughes, Harold J; Jungkunst, Hermann F; Gerold, Gerhard

2018-04-14

Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental setup to collect high-temporal-resolution hydrological and hydrochemical data in two pairs of low-order streams in catchments under contrasting land use and land cover (native vegetation vs. pasture) in the Amazon and Cerrado biomes. Our results indicate that the conversion of natural landscapes to pastures increases carbon and nutrient fluxes via streamflow in both biomes. These changes were the greatest in total inorganic carbon in the Amazon and in potassium in the Cerrado, representing a 5.0- and 5.5-fold increase in the fluxes of each biome, respectively. We found that stormflow, which is often neglected in studies on stream hydrochemistry in the tropics, plays a substantial role in the carbon and nutrient fluxes, especially in the Amazon biome, as its contributions to hydrochemical fluxes are mostly greater than the volumetric contribution to the total streamflow. These findings demonstrate that assessments of the impacts of deforestation in the Amazon and Cerrado biomes should also take into account rapid hydrological pathways; however, this can only be achieved through collection of high-temporal-resolution data. Copyright © 2018 Elsevier B.V. All rights reserved.

Bio-inspired Nano-capillary Self-powered Fluid Transport in Nanocomposite (NBIT III)

Science.gov (United States)

2017-02-22

crack is sealed, (c) photocatalytic HAP composite with TiO2/Ag, left; photocatalytic decomposition of organic pollutant-methylene blue with visible...Sci. Mater. Med., 9, 421, (1998). [8] Nancollas, G. H., “ Enamel apatite nucleation and crystal growth”, J. Dent. Res., 58B, 861, (1979). [9

BOREAS RSS-8 BIOME-BGC Model Simulations at Tower Flux Sites in 1994

Science.gov (United States)

Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

2000-01-01

BIOME-BGC is a general ecosystem process model designed to simulate biogeochemical and hydrologic processes across multiple scales (Running and Hunt, 1993). In this investigation, BIOME-BGC was used to estimate daily water and carbon budgets for the BOREAS tower flux sites for 1994. Carbon variables estimated by the model include gross primary production (i.e., net photosynthesis), maintenance and heterotrophic respiration, net primary production, and net ecosystem carbon exchange. Hydrologic variables estimated by the model include snowcover, evaporation, transpiration, evapotranspiration, soil moisture, and outflow. The information provided by the investigation includes input initialization and model output files for various sites in tabular ASCII format.

Climate control of terrestrial carbon exchange across biomes and continents

Science.gov (United States)

Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

2010-01-01

Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

Mastery of Content Representation (CoRes) Related TPACK High School Biology Teacher

Science.gov (United States)

Nasution, W. R.; Sriyati, S.; Riandi, R.; Safitri, M.

2017-09-01

The purpose of this study was to determine the mastery of Content Representation (CoRes) teachers related to the integration of technology and pedagogy in teaching Biology (TPACK). This research uses a descriptive method. The data were taken using instruments CoRes as the primary data and semi-structured interviews as supporting data. The subjects were biology teacher in class X MIA from four schools in Bandung. Teachers raised CoRes was analyzed using a scoring rubric CoRes with coding 1-3 then categorized into a group of upper, middle, or lower. The results showed that the two teachers in the lower category. This results means that the control of teachers in defining the essential concept in the CoRes has not been detailed and specific. Meanwhile, two other teachers were in the middle category. This means that the ability of teachers to determine the essential concepts in the CoRes are still inadequate so that still needs to be improved.

Mechanical properties of freeze-dried and irradiated bone chips, fascia lata and dura mater

International Nuclear Information System (INIS)

De Guzman, Z.M.; Vajaradul, Y.

1996-01-01

The comparison strengths of freeze-dried and irradiated bone chips such as three-dimensional cortex (3DC) and two-cortico cancellous (2CC) are investigated. The results show that the (3DC) exhibits a higher compression strength (1.2kN cm -2 in deep frozen states. Rehydration of the freeze-dried bone chips after 15 min with normal saline solution restores the strength of materials by 30%. The tensile strengths of fascia lata and dura mater are also studied. A marked decrease of tensile strength is noted in the irradiated and freeze-dried samples, however, reconstitution with normal saline solution restores the tensile strength of the tissues to about 40-56%. (author). 8 refs., 6figs

Modelling the carbon budget of intensive forest monitoring sites in Germany using the simulation model BIOME-BGC

OpenAIRE

Jochheim, H.; Puhlmann, M.; Beese, F.; Berthold, D.; Einert, P.; Kallweit, R.; Konopatzky, A.; Meesenburg, H.; Meiwes, K.-J.; Raspe, S.; Schulte-Bisping, H.; Schulz, C.

2008-01-01

It is shown that by calibrating the simulation model BIOME-BGC with mandatory and optional Level II data, within the ICP Forest programme, a well-founded calculation of the carbon budget of forest stands is achievable and, based on succeeded calibration, the modified BIOME-BGC model is a useful tool to assess the effect of climate change on forest ecosystems. peerReviewed

Res Publica Euroopas / Eiki Berg, Marko Mihkelson ; interv. Lauri Lugna

Index Scriptorium Estoniae

Berg, Eiki, 1970-

2003-01-01

Res Publica välispoliitika eksperdid Eiki Berg ja Marko Mihkelson vastavad küsimustele, mis käsitlevad Res Publica saamist Euroopa Rahvapartei (ERP) liikmeks, koostööd ERP-ga, EL-i põhiseaduslikku lepet

Biome-BGC: Modeling Effects of Disturbance and Climate (Thornton et al. 2002)

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This archived model product contains the directions, executables, and procedures for running Biome-BGC, Version 4.1.1, to recreate the results of the...

Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

Science.gov (United States)

Tonin, Alan M; Gonçalves, José F; Bambi, Paulino; Couceiro, Sheyla R M; Feitoza, Lorrane A M; Fontana, Lucas E; Hamada, Neusa; Hepp, Luiz U; Lezan-Kowalczuk, Vânia G; Leite, Gustavo F M; Lemes-Silva, Aurea L; Lisboa, Leonardo K; Loureiro, Rafael C; Martins, Renato T; Medeiros, Adriana O; Morais, Paula B; Moretto, Yara; Oliveria, Patrícia C A; Pereira, Evelyn B; Ferreira, Lidiane P; Pérez, Javier; Petrucio, Mauricio M; Reis, Deusiano F; S Rezende, Renan; Roque, Nadia; Santos, Luiz E P; Siegloch, Ana E; Tonello, Gabriela; Boyero, Luz

2017-09-07

Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m -2 y -1 , storage: 55, 113 and 38 g m -2 , on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

Concluding remarks: overall impacts on biodiversity and future perspectives for conservation in the Pantanal biome

Directory of Open Access Journals (Sweden)

CJR. Alho

Full Text Available The Pantanal biome is characterised by seasonal flooding which determines specific ecosystem processes, with the occurrence of adapted plants and animals to the annual shrinking and expansion of habitats due to the seasonal hydrological regime. Biodiversity abundance varies during the dry and wet seasons. The Pantanal's biodiversity is a fundamental component of ecosystem services for human society, including nutrient cycling, fish production, ecotourism, carbon storage, flood control, among others, which are relevant to regional and global environmental consequences. The biome has been impacted by the conversion of natural vegetation into agricultural fields and pasture for cattle raising, with alteration and loss of natural habitats and biodiversity. Major negative impacts occur in uplands, with drastic deforestation of savanna vegetation, where main rivers feeding the Pantanal have their springs. This article discusses future needs and priorities for ecological research, in order to better understand the biome's natural system, to achieve conservation and sustainable use.

Concluding remarks: overall impacts on biodiversity and future perspectives for conservation in the Pantanal biome.

Science.gov (United States)

Alho, C J R

2011-04-01

The Pantanal biome is characterised by seasonal flooding which determines specific ecosystem processes, with the occurrence of adapted plants and animals to the annual shrinking and expansion of habitats due to the seasonal hydrological regime. Biodiversity abundance varies during the dry and wet seasons. The Pantanal's biodiversity is a fundamental component of ecosystem services for human society, including nutrient cycling, fish production, ecotourism, carbon storage, flood control, among others, which are relevant to regional and global environmental consequences. The biome has been impacted by the conversion of natural vegetation into agricultural fields and pasture for cattle raising, with alteration and loss of natural habitats and biodiversity. Major negative impacts occur in uplands, with drastic deforestation of savanna vegetation, where main rivers feeding the Pantanal have their springs. This article discusses future needs and priorities for ecological research, in order to better understand the biome's natural system, to achieve conservation and sustainable use.

Aspectos biométricos do desenvolvimento testicular e corporal em cutias (Dasyprocta aguti criadas em cativeiros

Directory of Open Access Journals (Sweden)

Antônio Chaves de Assis-Neto

2003-01-01

Full Text Available Analisou-se os dados biométricos do desenvolvimento testicular e peso corporal de 31 cutias (Dasyprocta aguti desde o nascimento até os 14 meses de idade. As correlações entre o peso corporal, idade e parâmetros testiculares apresentaram-se altamente significativas. O peso testicular, o volume testicular, assim como os demais parâmetros biométricos testiculares (comprimento, diâmetro e perímetro, evoluíram lenta e gradualmente até os 8 meses de idade. A partir dos 9 meses, o crescimento foi mais rápido. O desenvolvimento biométrico do testículo pode ser dividido em duas fases, de 0 - 8 meses e de 9 - 14 meses de idade, sendo 9 meses considerado ponto de corte em se tratando de desenvolvimento testicular de cutias criadas em cativeiro.

Evaluating fire danger in Brazilian biomes: present and future patterns

Science.gov (United States)

Silva, Patrícia; Bastos, Ana; DaCamara, Carlos; Libonati, Renata

2017-04-01

Climate change is expected to have a significant impact on fire occurrence and activity, particularly in Brazil, a region known to be fire-prone [1]. The Brazilian savanna, commonly referred to as cerrado, is a fire-adapted biome covering more than 20% of the country's total area. It presents the highest numbers of fire events, making it particularly susceptible to changes in climate. It is thus essential to understand the present fire regimes in Brazilian biomes, in order to better evaluate future patterns. The CPTEC/INPE, the Brazilian Center for Weather Forecasting and Climate Research at the Brazilian National Institute of Space Research developed a fire danger index based on the occurrence of hundreds of thousands of fire events in the main Brazilian biomes [2]: the Meteorological Fire Danger Index (MFDI). This index indicates the predisposition of vegetation to be burned on a given day, for given climate conditions preceding that day. It relies on daily values of air temperature, relative humidity, accumulated precipitation and vegetation cover. In this study we aim to access the capability of the MFDI to accurately replicate present fire conditions for different biomes, with a special focus on cerrado. To this end, we assess the link between the MFDI as calculated by three different reanalysis (ERA-Interim, NCEP/DOE Reanalysis 2 and MERRA-2) and the observed burned area. We further calculate the validated MFDI using a regional climate model, the RCA4 as forced by EC-Earth from CORDEX, to understand the ability of the model to characterize present fire danger. Finally, the need to calibrate the model to better characterize future fire danger was also evaluated. This work was developed within the framework of the Brazilian Fire-Land-Atmosphere System (BrFLAS) Project financed by the Portuguese and Brazilian science foundations, FCT and FAPESP (project references FAPESP/1389/2014 and 2014/20042-2). [1] KRAWCHUK, M.A.; MORITZ, M.A.; PARISIEN, M.A.; VAN DORN, J

Intricate Resonant Raman Response in Anisotropic ReS2.

Science.gov (United States)

McCreary, Amber; Simpson, Jeffrey R; Wang, Yuanxi; Rhodes, Daniel; Fujisawa, Kazunori; Balicas, Luis; Dubey, Madan; Crespi, Vincent H; Terrones, Mauricio; Hight Walker, Angela R

2017-10-11

The strong in-plane anisotropy of rhenium disulfide (ReS 2 ) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS 2 also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS 2 or WS 2 ) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to nondestructively and sensitively probe the fundamental photophysics of a 2D material. Here, we perform a thorough study of the resonant Raman response of the 18 first-order phonons in ReS 2 at various layer thicknesses and crystal orientations. Remarkably, we discover that, as opposed to a general increase in intensity of all of the Raman modes at excitonic transitions, each of the 18 modes behave differently relative to each other as a function of laser excitation, layer thickness, and orientation in a manner that highlights the importance of electron-phonon coupling in ReS 2 . In addition, we correct an unrecognized error in the calculation of the optical interference enhancement of the Raman signal of transition metal dichalcogenides on SiO 2 /Si substrates that has propagated through various reports. For ReS 2 , this correction is critical to properly assessing the resonant Raman behavior. We also implemented a perturbation approach to calculate frequency-dependent Raman intensities based on first-principles and demonstrate that, despite the neglect of excitonic effects, useful trends in the Raman intensities of monolayer and bulk ReS 2 at different laser energies can be accurately captured. Finally, the phonon dispersion calculated from first-principles is used to address the possible origins of unexplained peaks observed in the Raman spectra, such as infrared-active modes, defects, and second-order processes.

Low complication rate of sellar reconstruction by artificial dura mater during endoscopic endonasal transsphenoidal surgery.

Science.gov (United States)

Ye, Yuanliang; Wang, Fuyu; Zhou, Tao; Luo, Yi

2017-12-01

To evaluate effect of sellar reconstruction during pituitary adenoma resection surgery by the endoscopic endonasal transsphenoidal approach using artificial cerebral dura mater patch.This was a retrospective study of 1281 patients who underwent endoscopic transsphenoidal resection for the treatment of pituitary adenomas between December 2006 and May 2014 at the Neurosurgery Department of the People's Liberation Army General Hospital. The patients were classified into 4 grades according to intraoperative cerebrospinal fluid (CSF) leakage site. All patients were followed up for 3 months by telephone and outpatient visits.One thousand seventy three (83.7%) patients underwent sellar reconstruction using artificial dura matter patched outside the sellar region (method A), 106 (8.3%) using artificial dura matter patched inside the sellar region (method B), and 102 (8.0%) using artificial dura matter and a mucosal flap (method C). Method A was used for grade 0-1 leakage, method B for grade 1 to 2 leakage, and method C for grade 2 to 3 leakage. During the 3-month follow-up, postoperative CSF leakage was observed in 7 patients (0.6%): 2 among patients who underwent method B (1.9%) and 5 among those who underwent method C (4.9%). Meningitis was diagnosed in 13 patients (1.0%): 2 among patients who underwent method A (0.2%), 4 among those who underwent method B (3.8%), and 7 among those who underwent method C (6.7%).Compared with other reconstruction methods, sellar reconstruction surgery that only use artificial dura mater as repair material had a low rate of complications. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Improved human endometrial stem cells differentiation into functional hepatocyte-like cells on a glycosaminoglycan/collagen-grafted polyethersulfone nanofibrous scaffold.

Science.gov (United States)

Khademi, Farzaneh; Ai, Jafar; Soleimani, Masoud; Verdi, Javad; Mohammad Tavangar, Seyed; Sadroddiny, Esmaeil; Massumi, Mohammad; Mahmoud Hashemi, Seyed

2017-11-01

Liver tissue engineering (TE) is rapidly emerging as an effective technique which combines engineering and biological processes to compensate for the shortage of damaged or destroyed liver tissues. We examined the viability, differentiation, and integration of hepatocyte-like cells on an electrospun polyethersulfone (PES) scaffold, derived from human endometrial stem cells (hEnSCs). Natural polymers were separately grafted on plasma-treated PES nanofibers, that is, collagen, heparan sulfate (HS) and collagen-HS. Galactosilated PES (PES-Gal) nanofibrous were created. The engineering and cell growth parameters were considered and compared with each sample. The cellular studies revealed increased cell survival, attachment, and normal morphology on the bioactive natural polymer-grafted scaffolds after 30 days of hepatic differentiation. The chemical and molecular assays displayed hepatocyte differentiation. These cells were also functional, showing glycogen storage, α-fetoprotein, and albumin secretion. The HS nanoparticle-grafted PES nanofibers demonstrated a high rate of cell proliferation, differentiation, and integration. Based on the observations mentioned above, engineered tissue is a good option in the future, for the commercial production of three-dimensional liver tissues for clinical purposes. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2516-2529, 2017. © 2016 Wiley Periodicals, Inc.

Bone engineering in dog mandible: Coculturing mesenchymal stem cells with endothelial progenitor cells in a composite scaffold containing vascular endothelial growth factor.

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Khojasteh, Arash; Fahimipour, Farahnaz; Jafarian, Mohammad; Sharifi, Davoud; Jahangir, Shahrbanoo; Khayyatan, Fahimeh; Baghaban Eslaminejad, Mohamadreza

2017-10-01

We sought to assess the effects of coculturing mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) in the repair of dog mandible bone defects. The cells were delivered in β-tricalcium phosphate scaffolds coated with poly lactic co-glycolic acid microspheres that gradually release vascular endothelial growth factor (VEGF). The complete scaffold and five partial scaffolds were implanted in bilateral mandibular body defects in eight beagles. The scaffolds were examined histologically and morphometrically 8 weeks after implantation. Histologic staining of the decalcified scaffolds demonstrated that bone formation was greatest in the VEGF/MSC scaffold (63.42 ± 1.67), followed by the VEGF/MSC/EPC (47.8 ± 1.87) and MSC/EPC (45.21 ± 1.6) scaffolds, the MSC scaffold (34.59 ± 1.49), the VEGF scaffold (20.03 ± 1.29), and the untreated scaffold (7.24 ± 0.08). Hence, the rate of new bone regeneration was highest in scaffolds containing MSC, either mixed with EPC or incorporating VEGF. Adding both EPC and VEGF with the MSC was not necessary. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1767-1777, 2017. © 2016 Wiley Periodicals, Inc.

Effect of silver-loaded PMMA on Streptococcus mutans in a drip flow reactor.

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Williams, Dustin L; Epperson, Richard Tyler; DeGrauw, Jeffery P; Nielsen, Mattias B; Taylor, Nicholas B; Jolley, Ryan D

2017-09-01

Orthodontic retention has been proposed as a life-long commitment for patients who desire to maintain straight teeth. However, the presence of foreign material increases risk of bacterial colonization and caries formation, of which Streptococcus mutans is a key contributor. Multiple studies have assessed the ability of silver to be added to base plate material and resist attachment of S. mutans. However, it does not appear that long-term washout in connection with biofilm growth under physiologically relevant conditions has been taken into consideration. In this study, silver was added to base plate material and exposed to short- or long-term washout periods. Materials were then assessed for their ability to resist biofilm formation of S. mutans using a drip flow reactor that modeled the human oral environment. Data indicated that silver was able to resist biofilm formation following short-term washout, but long-term washout periods resulted in a lack of ability to resist biofilm formation. These data will be important for future development of base plate materials to achieve long-term antimicrobial efficacy to reduce risk of caries formation and benefit patients in the long term. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2632-2639, 2017. © 2017 Wiley Periodicals, Inc.

Design and efficacy of a single-use bioreactor for heart valve tissue engineering.

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Converse, Gabriel L; Buse, Eric E; Neill, Kari R; McFall, Christopher R; Lewis, Holley N; VeDepo, Mitchell C; Quinn, Rachael W; Hopkins, Richard A

2017-02-01

Heart valve tissue engineering offers the promise of improved treatments for congenital heart disorders; however, widespread clinical availability of a tissue engineered heart valve (TEHV) has been hindered by scientific and regulatory concerns, including the lack of a disposable, bioreactor system for nondestructive valve seeding and mechanical conditioning. Here we report the design for manufacture and the production of full scale, functional prototypes of such a system. To evaluate the efficacy of this bioreactor as a tool for seeding, ovine aortic valves were decellularized and subjected to seeding with human mesenchymal stem cells (hMSC). The effects of pulsatile conditioning using cyclic waveforms tuned to various negative and positive chamber pressures were evaluated, with respect to the seeding of cells on the decellularized leaflet and the infiltration of seeded cells into the interstitium of the leaflet. Infiltration of hMSCs into the aortic valve leaflet was observed following 72 h of conditioning under negative chamber pressure. Additional conditioning under positive pressure improved cellular infiltration, while retaining gene expression within the MSC-valve interstitial cell phenotype lineage. This protocol resulted in a subsurface pilot population of cells, not full tissue recellularization. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 249-259, 2017. © 2015 Wiley Periodicals, Inc.

Polydimethyl siloxane based nanocomposites with antibiofilm properties for biomedical applications.

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Sankar, G Gomathi; Murthy, P Sriyutha; Das, Arindam; Sathya, S; Nankar, Rakesh; Venugopalan, V P; Doble, Mukesh

2017-07-01

Polydimethyl siloxane (PDMS) is an excellent implant material for biomedical applications, but often fails as it is prone to microbial colonization which forms biofilms. In the present study CuO, CTAB capped CuO, and ZnO nanoparticles were tested as nanofillers to enhance the antibiofilm property of PDMS against Staphylococcus aureus and Escherichia coli. In general S. aurues (Gram positive and more hydrophobic) favor PDMS surface than glass while E. coli (Gram negative and more hydrophilic) behaves in a reverse way. Incorporation of nanofillers renders the PDMS surface antibacterial and reduces the attachment of both bacteria. These surfaces are also not cytotoxic nor show any cell damage. Contact angle of the material and the cell surface hydrophobicity influenced the extent of bacterial attachment. Cell viability in biofilms was dependent on the antimicrobial property of the nanoparticles incorporated in the PDMS matrix. Simple regression relationships were able to predict the bacterial attachment and number of dead cells on these nanocomposites. Among the nanocomposites tested, PDMS incorporated with CTAB (cetyl trimethylammonium bromide)-capped CuO appears to be the best antibacterial material with good cyto-compatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1075-1082, 2017. © 2016 Wiley Periodicals, Inc.

Three dimensional printed calcium phosphate and poly(caprolactone) composites with improved mechanical properties and preserved microstructure.

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Vella, Joseph B; Trombetta, Ryan P; Hoffman, Michael D; Inzana, Jason; Awad, Hani; Benoit, Danielle S W

2018-03-01

Biphasic calcium phosphate scaffolds formed via three dimensional (3D) printing technology to exhibit porosity and chemical resorbability to promote osseointegration often lack the strength and toughness required to withstand loading in bone tissue engineering applications. Herein, sintering and CaP:poly(caprolactone) (PCL) composite formation were explored to improve 3D printed scaffold strength and toughness. Hydroxyapatite and α-tricalcium phosphate (α-TCP) biphasic calcium powders were printed using phosphoric acid binder, which generated monetite and hydroxyapatite scaffolds. Upon sintering, evolution of β-TCP was observed along with an increase in flexural strength and modulus but no effect on fracture toughness was observed. Furthermore, scaffold porosity increased with sintering. Additionally, two techniques of PCL composite formation were employed: postprint precipitation and 3D print codeposition to further augment scaffold mechanical properties. While both techniques significantly improved flexural strength, flexural modulus, and fracture toughness under most conditions explored, precipitation yielded more substantial increases in these properties, which is attributed to better continuity of the PCL phase. However, precipitation also compromised surface porosity due to PCL passivation of the calcium phosphate surface, which may subsequently hinder scaffold integration and bone regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 663-672, 2018. © 2017 Wiley Periodicals, Inc.

The pathology of the foreign body reaction against biomaterials.

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Klopfleisch, R; Jung, F

2017-03-01

The healing process after implantation of biomaterials involves the interaction of many contributing factors. Besides their in vivo functionality, biomaterials also require characteristics that allow their integration into the designated tissue without eliciting an overshooting foreign body reaction (FBR). The targeted design of biomaterials with these features, thus, needs understanding of the molecular mechanisms of the FBR. Much effort has been put into research on the interaction of engineered materials and the host tissue. This elucidated many aspects of the five FBR phases, that is protein adsorption, acute inflammation, chronic inflammation, foreign body giant cell formation, and fibrous capsule formation. However, in practice, it is still difficult to predict the response against a newly designed biomaterial purely based on the knowledge of its physical-chemical surface features. This insufficient knowledge leads to a high number of factors potentially influencing the FBR, which have to be analyzed in complex animal experiments including appropriate data-based sample sizes. This review is focused on the current knowledge on the general mechanisms of the FBR against biomaterials and the influence of biomaterial surface topography and chemical and physical features on the quality and quantity of the reaction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 927-940, 2017. © 2016 Wiley Periodicals, Inc.

Construction of human induced pluripotent stem cell-derived oriented bone matrix microstructure by using in vitro engineered anisotropic culture model.

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Ozasa, Ryosuke; Matsugaki, Aira; Isobe, Yoshihiro; Saku, Taro; Yun, Hui-Suk; Nakano, Takayoshi

2018-02-01

Bone tissue has anisotropic microstructure based on collagen/biological apatite orientation, which plays essential roles in the mechanical and biological functions of bone. However, obtaining an appropriate anisotropic microstructure during the bone regeneration process remains a great challenging. A powerful strategy for the control of both differentiation and structural development of newly-formed bone is required in bone tissue engineering, in order to realize functional bone tissue regeneration. In this study, we developed a novel anisotropic culture model by combining human induced pluripotent stem cells (hiPSCs) and artificially-controlled oriented collagen scaffold. The oriented collagen scaffold allowed hiPSCs-derived osteoblast alignment and further construction of anisotropic bone matrix which mimics the bone tissue microstructure. To the best of our knowledge, this is the first report showing the construction of bone mimetic anisotropic bone matrix microstructure from hiPSCs. Moreover, we demonstrated for the first time that the hiPSCs-derived osteoblasts possess a high level of intact functionality to regulate cell alignment. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 360-369, 2018. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

Long-term healing of mildly cross-linked decellularized bovine pericardial aortic patch.

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Umashankar, P R; Sabareeswaran, A; Shenoy, Sachin J

2017-10-01

Glutaraldehyde treated bovine pericardium is extensively used in cardiovascular surgery. However, frequent occurrence of failure modes, such as calcification and structural failure, has hard pressed the need for finding an alternate technology. Decellularized bovine pericardium is an emerging technology. Mildly cross-linked decellularized bovine pericardium promotes positive remodeling with insignificant calcification and acute inflammation. In the present study, mildly cross-linked decellularized bovine pericardium was evaluated as a cardiovascular patch by studying mechanical strength as well as graft remodeling, resistance to calcific degeneration and inflammatory response using long duration porcine aortic implantation. It was observed that decellularized bovine pericardium, although thinner and less elastic had equivalent tensile properties such as tensile strength and stiffness when compared to commercially available glutaraldehyde-treated bovine pericardium. It showed the potential for site appropriate remodeling evidenced by host cell incorporation, thinner neointima, graft degradation, and neocollagenisation making it suitable for vascular patch application, whereas glutaraldehyde-treated pericardium failed to integrate with host tissue through timely degradation and host cell incorporation or neocollagenization. Conversely, it elicited persistent acute inflammation and produced calcification. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2145-2152, 2017. © 2016 Wiley Periodicals, Inc.

Potential effects of a low-molecular-weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties.

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Changotade, S Igondjo Tchen; Korb, G; Bassil, J; Barroukh, B; Willig, C; Colliec-Jouault, S; Durand, P; Godeau, G; Senni, K

2008-12-01

In this work, we first tested the influence of low-molecular-weight (LMW) fucoidan extracted from pheophicae cell wall on bidimensional cultured normal human osteoblasts' behaviors. Second, by impregnation procedure with LMW fucoidan of bone biomaterial (Lubboc), we explored in this bone extracellular matrix context its capabilities to support human osteoblastic behavior in 3D culture. In bidimensionnal cultures, we evidenced that LMW fucoidan promotes human osteoblast proliferation and collagen type I expression and favors precocious alkaline phosphatase activity. Furthermore, with LMW fucoidan, von Kossa's staining was positive at 30 days and positive only at 45 days in the absence of LMW fucoidan. In our three-dimensional culture models with the biomaterial pretreated with LMW fucoidan, osteoblasts promptly overgrew the pretreated biomaterial. We also evidenced that osteoblasts increased proliferation with pretreated biomaterial when compared with untreated biomaterial. Osteoblasts secreted osteocalcin and expressed BMP2 receptor on control material as well as with LMW fucoidan impregnated biomaterial. In conclusion, in our experimental conditions, LMW fucoidan stimulated expression of osteoblastic markers differentiation such as alkaline phosphatase activity, collagen type I expression, and mineral deposition; furthermore, cell proliferation was favored. These findings suggest that fucoidan could be clinically useful for bone regeneration and bone substitute design. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

Deposition of mannose-binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass.

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Eppa, Łukasz; Pągowska-Klimek, Izabela; Świerzko, Anna S; Moll, Maciej; Krajewski, Wojciech R; Cedzyński, Maciej

2018-04-01

The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1202-1208, 2018. © 2017 Wiley Periodicals, Inc.

Chitosan porous 3D scaffolds embedded with resolvin D1 to improve in vivo bone healing.

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Vasconcelos, Daniela P; Costa, Madalena; Neves, Nuno; Teixeira, José H; Vasconcelos, Daniel M; Santos, Susana G; Águas, Artur P; Barbosa, Mário A; Barbosa, Judite N

2018-06-01

The aim of this study was to investigate the effect chitosan (Ch) porous 3D scaffolds embedded with resolvin D1 (RvD1), an endogenous pro-resolving lipid mediator, on bone tissue healing. These scaffolds previous developed by us have demonstrated to have immunomodulatory properties namely in the modulation of the macrophage inflammatory phenotypic profile in an in vivo model of inflammation. Herein, results obtained in an in vivo rat femoral defect model demonstrated that two months after Ch + RvD1 scaffolds implantation, an increase in new bone formation, in bone trabecular thickness, and in collagen type I and Coll I/Coll III ratio were observed. These results suggest that Ch scaffolds embedded with RvD1 were able to lead to the formation of new bone with improvement of trabecular thickness. This study shows that the presence of RvD1 in the acute phase of the inflammatory response to the implanted biomaterial had a positive role in the subsequent bone tissue repair, thus demonstrating the importance of innovative approaches for the control of immune responses to biomedical implants in the design of advanced strategies for regenerative medicine. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1626-1633, 2018. © 2018 Wiley Periodicals, Inc.

Genipin crosslinker releasing sutures for improving the mechanical/repair strength of damaged connective tissue.

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Sundararaj, Sharath; Slusarewicz, Paul; Brown, Matt; Hedman, Thomas

2017-11-01

The most common mode of surgical repair of ruptured tendons and ligaments involves the use of sutures for reattachment. However, there is a high incidence of rerupture and repair failure due to pulling out of the suture material from the damaged connective tissue. The main goal of this research was to achieve a localized delivery of crosslinking agent genipin (GP) from rapid-release biodegradable coatings on sutures, for strengthening the repair of ruptured connective tissue. Our hypothesis is that GP released from the suture coating will lead to exogenous crosslinking of native connective tissue resulting in beneficial effects on clinically relevant mechanical parameters such as tear resistance, tissue strength, and energy required to rupture the tissue (toughness). Sutures were successfully coated with a biodegradable polymer layer loaded with the crosslinking agent genipin, without compromising the mechanical properties of the suture. The rapid-release of genipin was achieved under both in vitro and ex vivo conditions. Exogenous crosslinking using these genipin releasing sutures was demonstrated using equine tendons. The tendons treated with genipin releasing sutures showed significant improvement in failure load, energy required for pull-out failure, and stiffness. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2199-2205, 2017. © 2016 Wiley Periodicals, Inc.

Tribology of flexible and sliding spinal implants: Development of experimental and numerical models.

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Le Cann, Sophie; Chaves-Jacob, Julien; Rossi, Jean-Marie; Linares, Jean-Marc; Chabrand, Patrick

2018-01-01

New fusionless devices are being developed to get over the limits of actual spinal surgical treatment, based on arthrodesis. However, due to their recentness, no standards exist to test and validate those devices, especially concerning the wear. A new tribological first approach to the definition of an in vitro wear protocol to study wear of flexible and sliding spinal devices is presented in this article, and was applied to a new concept. A simplified synthetic spine portion (polyethylene) was developed to reproduce a simple supra-physiological spinal flexion (10° between two vertebrae). The device studied with this protocol was tested in wet environment until 1 million cycles (Mc). We obtained an encouraging estimated wear volume of same order of magnitude compared to similar devices. An associated finite element (FE) numerical model has permitted to access contact information and study the effect of misalignment of one screw. First results could point out how to improve the design and suggest that a vertical misalignment of a screw (under or over-screwing) has more impact than a horizontal one. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 104-111, 2018. © 2016 Wiley Periodicals, Inc.

The impact of plasma rich in growth factors on clinical and biological factors involved in healing processes after third molar extraction.

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Mozzati, Marco; Martinasso, Germana; Pol, Renato; Polastri, Carolina; Cristiano, Antonio; Muzio, Giuliana; Canuto, Rosa

2010-12-01

Extraction of an impacted mandibular third molar is a common surgical procedure, although it still leads to several postoperative symptoms and complications. The study assessed the efficacy of autologous plasma rich in growth factors (PRGF) in the healing process by checking the difference of tissue cytokines and other healing factors produced by the mucosa after extraction between sites treated with PRGF and control sites and, at the same time, by evaluating the clinical efficacy of PRGF in terms of reduced pain and facial swelling. This study was a split-mouth study, in which the patient becomes his/her own control, to eliminate any individual response differences toward PRGF treatment. The parameters regarding inflammation and subsequent wound healing were all significantly higher at PRGF sites than at control sites. The increase at PRGF sites of the two proinflammatory cytokines evaluated, interleukin (IL)-1β and IL-6, was accompanied by the increase of two anti-inflammatory cytokines, IL-10 and transforming growth factor-β. Furthermore, IL-1β and IL-6 induce fibroblast and keratinocyte proliferation, important events in wound healing. Postoperative pain and the swelling, measured at all experimental times, were reduced in the presence of PRGF. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Transferrin-conjugated magnetic dextran-spermine nanoparticles for targeted drug transport across blood-brain barrier.

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Ghadiri, Maryam; Vasheghani-Farahani, Ebrahim; Atyabi, Fatemeh; Kobarfard, Farzad; Mohamadyar-Toupkanlou, Farzaneh; Hosseinkhani, Hossein

2017-10-01

Application of many vital hydrophilic medicines have been restricted by blood-brain barrier (BBB) for treatment of brain diseases. In this study, a targeted drug delivery system based on dextran-spermine biopolymer was developed for drug transport across BBB. Drug loaded magnetic dextran-spermine nanoparticles (DS-NPs) were prepared via ionic gelation followed by transferrin (Tf) conjugation as targeting moiety. The characteristics of Tf conjugated nanoparticles (TDS-NPs) were analyzed by different methods and their cytotoxicity effects on U87MG cells were tested. The superparamagnetic characteristic of TDS-NPs was verified by vibration simple magnetometer. Capecitabine loaded TDS-NPs exhibited pH-sensitive release behavior with enhanced cytotoxicity against U87MG cells, compared to DS-NPs and free capecitabine. Prussian-blue staining and TEM-imaging showed the significant cellular uptake of TDS-NPs. Furthermore, a remarkable increase of Fe concentrations in brain was observed following their biodistribution and histological studies in vivo, after 1 and 7 days of post-injection. Enhanced drug transport across BBB and pH-triggered cellular uptake of TDS-NPs indicated that these theranostic nanocarriers are promising candidate for the brain malignance treatment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2851-2864, 2017. © 2017 Wiley Periodicals, Inc.

Susceptibility of metallic magnesium implants to bacterial biofilm infections.

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Rahim, Muhammad Imran; Rohde, Manfred; Rais, Bushra; Seitz, Jan-Marten; Mueller, Peter P

2016-06-01

Magnesium alloys have promising mechanical and biological properties as biodegradable medical implant materials for temporary applications during bone healing or as vascular stents. Whereas conventional implants are prone to colonization by treatment resistant microbial biofilms in which bacteria are embedded in a protective matrix, magnesium alloys have been reported to act antibacterial in vitro. To permit a basic assessment of antibacterial properties of implant materials in vivo an economic but robust animal model was established. Subcutaneous magnesium implants were inoculated with bacteria in a mouse model. Contrary to the expectations, bacterial activity was enhanced and prolonged in the presence of magnesium implants. Systemic antibiotic treatments were remarkably ineffective, which is a typical property of bacterial biofilms. Biofilm formation was further supported by electron microscopic analyses that revealed highly dense bacterial populations and evidence for the presence of extracellular matrix material. Bacterial agglomerates could be detected not only on the implant surface but also at a limited distance in the peri-implant tissue. Therefore, precautions may be necessary to minimize risks of metallic magnesium-containing implants in prospective clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1489-1499, 2016. © 2016 Wiley Periodicals, Inc.

Phosphate conversion coating reduces the degradation rate and suppresses side effects of metallic magnesium implants in an animal model.

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Rahim, Muhammad Imran; Tavares, Ana; Evertz, Florian; Kieke, Marc; Seitz, Jan-Marten; Eifler, Rainer; Weizbauer, Andreas; Willbold, Elmar; Jürgen Maier, Hans; Glasmacher, Birgit; Behrens, Peter; Hauser, Hansjörg; Mueller, Peter P

2017-08-01

Magnesium alloys have promising mechanical and biological properties for the development of degradable implants. However, rapid implant corrosion and gas accumulations in tissue impede clinical applications. With time, the implant degradation rate is reduced by a highly biocompatible, phosphate-containing corrosion layer. To circumvent initial side effects after implantation it was attempted to develop a simple in vitro procedure to generate a similarly protective phosphate corrosion layer. To this end magnesium samples were pre-incubated in phosphate solutions. The resulting coating was well adherent during routine handling procedures. It completely suppressed the initial burst of corrosion and it reduced the average in vitro magnesium degradation rate over 56 days almost two-fold. In a small animal model phosphate coatings on magnesium implants were highly biocompatible and abrogated the appearance of gas cavities in the tissue. After implantation, the phosphate coating was replaced by a layer with an elemental composition that was highly similar to the corrosion layer that had formed on plain magnesium implants. The data demonstrate that a simple pre-treatment could improve clinically relevant properties of magnesium-based implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1622-1635, 2017. © 2016 Wiley Periodicals, Inc.

Optimization of SDS exposure on preservation of ECM characteristics in whole organ decellularization of rat kidneys.

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He, M; Callanan, A; Lagaras, K; Steele, J A M; Stevens, M M

2017-08-01

Renal transplantation is well established as the optimal form of renal replacement therapy but is restricted by the limited pool of organs available for transplantation. The whole organ decellularisation approach is leading the way for a regenerative medicine solution towards bioengineered organ replacements. However, systematic preoptimization of both decellularization and recellularization parameters is essential prior to any potential clinical application and should be the next stage in the evolution of whole organ decellularization as a potential strategy for bioengineered organ replacements. Here we have systematically assessed two fundamental parameters (concentration and duration of perfusion) with regards to the effects of differing exposure to the most commonly used single decellularizing agent (sodium dodecyl sulphate/SDS) in the perfusion decellularization process for whole rat kidney ECM bioscaffolds, with findings showing improved preservation of both structural and functional components of the whole kidney ECM bioscaffold. Whole kidney bioscaffolds based on our enhanced protocol were successfully recellularized with rat primary renal cells and mesenchymal stromal cells. These findings should be widely applicable to decellularized whole organ bioscaffolds and their optimization in the development of regenerated organ replacements for transplantation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1352-1360, 2017. © 2016 Wiley Periodicals, Inc.

Bioactivity tests of calcium phosphates with variant molar ratios of main components.

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Pluta, Klaudia; Sobczak-Kupiec, Agnieszka; Półtorak, Olga; Malina, Dagmara; Tyliszczak, Bożena

2018-03-09

Calcium phosphates constitute attractive materials of biomedical applications. Among them particular attention is devoted to bioactive hydroxyapatite (HAp) and bioresorbable tricalcium phosphate (TCP) that possess ability to bind to living bones and can be used clinically as important bone substitutes. Notably, in vivo bone bioactivity can be predicted from apatite formation of bone immersed in SBF fluids. Thus, analyses of behavior of calcium phosphates immersed in various bio fluids are of great importance. Recently, stoichiometric HAp and TCP structures have been widely studied, whereas only limited number of publications have been devoted to analyses of nonstoichiometric calcium phosphates. Here, we report physicochemical analysis of natural and synthetic phosphates with variable Ca/P molar ratios. Subsequently attained structures were subjected to incubation in either artificial saliva or Ringer's fluids. Both pH and conductivity of such fluids were determined before and after incubation. Furthermore, the influence of the Ca/P values on such parameters was exemplified. Physicochemical analysis of received materials was performed by XRD and FT-IR characterization techniques. Their potential antibacterial activity and behavior in the presence of infectious microorganisms as Escherichia coli and Staphylococcus aureus was also evaluated. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

Nanofiber mats composed of a chitosan-poly(d,l-lactic-co-glycolic acid)-poly(ethylene oxide) blend as a postoperative anti-adhesion agent.

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Ko, Jae Eok; Ko, Young-Gwang; Kim, Won Il; Kwon, Oh Kyoung; Kwon, Oh Hyeong

2017-10-01

Postoperative tissue adhesion causes serious complications and suffering in 90% of patients after peritoneum surgery, while commercial anti-adhesion agents cannot completely prevent postoperative peritoneal adhesions. This study demonstrates electrospining of a blended solution of chitosan, poly(d,l-lactic-co-glycolic acid) (PLGA), and poly(ethylene oxide) (PEO) to fabricate a chitosan-based nanofibrous mat as a postoperative anti-adhesion agent. Rheological studies combined with scanning electron microscopy reveal that the spinnability of the chitosan-PLGA solution could be controlled by adjusting the blend ratio and concentration with average fiber diameter from 634 to 913 nm. Biodegradation of the nanofiber specimens showed accelerated hydrolysis by chitosan. Proliferation of fibroblasts and antimicrobial activity of nanofibers containing chitosan was analyzed. Abdominal defects with cecum adhesion in rats demonstrated that the blend nanofiber mats were effective in preventing tissue adhesion as a barrier (4 weeks after abdominal surgery) by coverage of exfoliated peritoneum and insufficient wound sites at the beginning of the wound healing process. Chitosan-PLGA-PEO blend nanofiber mats will provide a promising key as a postoperative anti-adhesion agent. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1906-1915, 2017. © 2016 Wiley Periodicals, Inc.

Effect of ceramic calcium-phosphorus ratio on chondrocyte-mediated biosynthesis and mineralization.

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Boushell, Margaret K; Khanarian, Nora T; LeGeros, Raquel Z; Lu, Helen H

2017-10-01

The osteochondral interface functions as a structural barrier between cartilage and bone, maintaining tissue integrity postinjury and during homeostasis. Regeneration of this calcified cartilage region is thus essential for integrative cartilage healing, and hydrogel-ceramic composite scaffolds have been explored for calcified cartilage formation. The objective of this study is to test the hypothesis that Ca/P ratio of the ceramic phase of the composite scaffold regulates chondrocyte biosynthesis and mineralization potential. Specifically, the response of deep zone chondrocytes to two bioactive ceramics with different calcium-phosphorus ratios (1.35 ± 0.01 and 1.41 ± 0.02) was evaluated in agarose hydrogel scaffolds over two weeks in vitro. It was observed that the ceramic with higher calcium-phosphorus ratio enhanced chondrocyte proliferation, glycosaminoglycan production, and induced an early onset of alkaline phosphorus activity, while the ceramic with lower calcium-phosphorus ratio performed similarly to the ceramic-free control. These results underscore the importance of ceramic bioactivity in directing chondrocyte response, and demonstrate that Ca/P ratio is a key parameter to be considered in osteochondral scaffold design. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2694-2702, 2017. © 2017 Wiley Periodicals, Inc.

Cytotoxicity evaluation of ceramic particles of different sizes and shapes.

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Yamamoto, Akiko; Honma, Rieko; Sumita, Masae; Hanawa, Takao

2004-02-01

When artificial hip or knee joints are implanted in the human body, they release metallic, ceramic, and polymeric debris into the surrounding tissues. The toxicity of the released particles is of two types: chemical, caused by the released soluble ions and monomers, and mechanical, a result of mechanical stimulation produced by the insoluble particles. In this study, the cytotoxicity of particles of TiO2, Al2O3, ZrO2, Si3N4, and SiC for murine fibroblasts and macrophages were examined to evaluate just their mechanical toxicity because these particles are not expected to release soluble metal ions. Different sizes and shapes of TiO2 particles were used to evaluate the effect of size and shape on particle cytotoxicity. The results suggest that the cytotoxicity of ceramic particles does not depend on their chemical species. Cytotoxicity levels were lower than those of corresponding metal ions, indicating that the mechanical toxicity of particles is lower than the chemical toxicity of released soluble ions and monomers. The differences in size did not affect the mechanical toxicity of these particles. The dendritic particles had a higher cytotoxicity level for macrophages than did spindle and spheric particles. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 244-256, 2004

Different methods of dentin processing for application in bone tissue engineering: A systematic review.

Science.gov (United States)

Tabatabaei, Fahimeh Sadat; Tatari, Saeed; Samadi, Ramin; Moharamzadeh, Keyvan

2016-10-01

Dentin has become an interesting potential biomaterial for tissue engineering of oral hard tissues. It can be used as a scaffold or as a source of growth factors in bone tissue engineering. Different forms of dentin have been studied for their potential use as bone substitutes. Here, we systematically review different methods of dentin preparation and the efficacy of processed dentin in bone tissue engineering. An electronic search was carried out in PubMed and Scopus databases for articles published from 2000 to 2016. Studies on dentin preparation for application in bone tissue engineering were selected. The initial search yielded a total of 1045 articles, of which 37 were finally selected. Review of studies showed that demineralization was the most commonly used dentin preparation process for use in tissue engineering. Dentin extract, dentin particles (tooth ash), freeze-dried dentin, and denatured dentin are others method of dentin preparation. Based on our literature review, we can conclude that preparation procedure and the size and shape of dentin particles play an important role in its osteoinductive and osteoconductive properties. Standardization of these methods is important to draw a conclusion in this regard. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2616-2627, 2016. © 2016 Wiley Periodicals, Inc.

Comparative study of different seeding methods based on a multilayer SIS scaffold: Which is the optimal procedure for urethral tissue engineering?

Science.gov (United States)

Lv, Xiang-Guo; Feng, Chao; Fu, Qiang; Xie, Hong; Wang, Ying; Huang, Jian-Wen; Xie, Min-Kai; Atala, Anthony; Xu, Yue-Min; Zhao, Wei-Xin

2016-08-01

Seeding cells efficiently and uniformly onto three-dimensional scaffolds is key for engineering urological tissue with an ideal histological structure in vitro. Using an optimized seeding technology allows cells to cooperate positively with biomaterials, resulting in successful reconstructive surgery. In this study, we used four different types of seeding methods in a scaffold of small intestinal submucosa (SIS). The efficiency of the sandwich co-culture, layered co-culture, static-agitation seeding, and centrifugation seeding methods were compared. It was demonstrated that dynamic seeding methods, such as static-agitation and centrifugation seeding, had superior cell-matrix infiltration and mechanical properties. The seeding time could be reduced by 5-10 min using the centrifugation method. Furthermore, functional assessment of the barriers revealed that this function was better in the centrifugation seeding method than in any other method. Our study suggests that both the static-agitation and centrifugation methods are suitable for cell seeding on SIS. There is no significant change in surface area of SIS with different seeding methods. These methods reinforce the physiological and mechanical properties of biomaterials and allow for the future in vivo study of tissue-engineered urethral reconstruction. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1098-1108, 2016. © 2015 Wiley Periodicals, Inc.

Design and demonstration of an intracortical probe technology with tunable modulus.

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Simon, Dustin M; Charkhkar, Hamid; St John, Conan; Rajendran, Sakthi; Kang, Tong; Reit, Radu; Arreaga-Salas, David; McHail, Daniel G; Knaack, Gretchen L; Sloan, Andrew; Grasse, Dane; Dumas, Theodore C; Rennaker, Robert L; Pancrazio, Joseph J; Voit, Walter E

2017-01-01

Intracortical probe technology, consisting of arrays of microelectrodes, offers a means of recording the bioelectrical activity from neural tissue. A major limitation of existing intracortical probe technology pertains to limited lifetime of 6 months to a year of recording after implantation. A major contributor to device failure is widely believed to be the interfacial mechanical mismatch of conventional stiff intracortical devices and the surrounding brain tissue. We describe the design, development, and demonstration of a novel functional intracortical probe technology that has a tunable Young's modulus from ∼2 GPa to ∼50 MPa. This technology leverages advances in dynamically softening materials, specifically thiol-ene/acrylate thermoset polymers, which exhibit minimal swelling of memory polymer-based multichannel intracortical probe can be fabricated, that the mechanical properties are stable for at least 2 months and that the device is capable of single unit recordings for durations up to 77 days in vivo. This novel technology, which is amenable to processes suitable for manufacturing via standard semiconductor fabrication techniques, offers the capability of softening in vivo to reduce the tissue-device modulus mismatch to ultimately improve long term viability of neural recordings. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 159-168, 2017. © 2016 Wiley Periodicals, Inc.

Comparison of high‐intensity sound and mechanical vibration for cleaning porous titanium cylinders fabricated using selective laser melting

Science.gov (United States)

Seiffert, Gary; Sutcliffe, Chris

2015-01-01

Abstract Orthopedic components, such as the acetabular cup in total hip joint replacement, can be fabricated using porous metals, such as titanium, and a number of processes, such as selective laser melting. The issue of how to effectively remove loose powder from the pores (residual powder) of such components has not been addressed in the literature. In this work, we investigated the feasibility of two processes, acoustic cleaning using high‐intensity sound inside acoustic horns and mechanical vibration, to remove residual titanium powder from selective laser melting‐fabricated cylinders. With acoustic cleaning, the amount of residual powder removed was not influenced by either the fundamental frequency of the horn used (75 vs. 230 Hz) or, for a given horn, the number of soundings (between 1 and 20). With mechanical vibration, the amount of residual powder removed was not influenced by the application time (10 vs. 20 s). Acoustic cleaning was found to be more reliable and effective in removal of residual powder than cleaning with mechanical vibration. It is concluded that acoustic cleaning using high‐intensity sound has significant potential for use in the final preparation stages of porous metal orthopedic components. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 117–123, 2017. PMID:26426906

DPSC colonization of functionalized 3D textiles.

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Ortiz, Marine; Rosales-Ibáñez, Raúl; Pozos-Guillén, Amaury; De Bien, Charlotte; Toye, Dominique; Flores, Héctor; Grandfils, Christian

2017-05-01

Fiber scaffolds are attractive materials for mimicking, within a 3D in vitro system, any living environment in which animal cells can adhere and proliferate. In three dimensions, cells have the ability to communicate and organize into complex architectures similar to those found in their natural environments. The aim of this study was to evaluate, in terms of cell reactivity, a new in vitro cell model: dental pulp stem cells (DPSCs) in a 3D polymeric textile. Scaffolds were knitted from polyglycolic acid (PGA) or polydioxanone (PDO) fibers differing in surface roughness. To promote cell adhesion, these hydrophobic fabrics were also functionalized with either chitosan or the peptide arginine-glycine-aspartic acid (RGD). Cell behavior was examined 1, 10, and 21 days post-seeding with a LIVE/DEAD ® Kit. Confocal laser scanning microscopy (CLSM) highlighted the biocompatibility of these materials (cell survival rate: 94% to 100%). Fiber roughness was found to influence cell adhesion and viability significantly and favorably. A clear benefit of polymeric textile functionalization with chitosan or RGD was demonstrated in terms of cell adhesion and viability. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 785-794, 2017. © 2016 Wiley Periodicals, Inc.

A remarkable finding that suggests the existence of a new groundwater biome based on chemoautotrophic resources, named

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Ştefan Negrea

2009-01-01

Full Text Available An important work of subterranean biology, signed by Francis Dov Por, Ophel: a groundwater biome based on chemoautotrophic resources. The global significance of the Ayyalon cave finds, Israel is presented and discussed in the present paper. The subject is a remarkable discovery suggesting the existence of a new aquatic subterranean biome autonomous energy based the author calls Ophel, the Hebrew word for “darkness” and “netherworld”. For F.D. Por, this biome links different marine chemosynthetic ecosystems in a global biospheric entity. Finally, F.D. POR hypothesizes on the existence of three overlapped biospheres: the bacteriosphere in the depths of the planet’s crust, which does not require light or oxygen; the aphotic, subterranean deuterobiosphere, formed of bacterial chemosynthesis based eukaryotes and limited-supplied dissolved oxygen from above-ground; the above-ground eubiosphere, based on aerobic photosynthesis. I would like to emphasize that, at my suggestion, Prof. Dr. F.D. Por participated at the 18th International Symposium of Biospeleology from Cluj-Napoca (Romania at 10th to 15th July 2006 where he mentioned for the first time orally some data on the Ayyalon Cave and the Ophel biome.

Modelling the impacts of reoccurring fires in tropical savannahs using Biome-BGC.

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Fletcher, Charlotte; Petritsch, Richard; Pietsch, Stephan

2010-05-01

Fires are a dominant feature of tropical savannahs and have occurred throughout history by natural as well as human-induced means. These fires have a profound influence on the landscape in terms of flux dynamics and vegetative species composition. This study attempts to understand the impacts of fire regimes on flux dynamics and vegetation composition in savannahs using the Biome-BGC model. The Batéké Plateau, Gabon - an area of savannah grasslands in the Congo basin, serves as a case-study. To achieve model validation for savannahs, data sets from stands with differing levels of past burning are used. It is hypothesised that the field measurements from those stands with lower-levels of past burning will correlate with the Biome-BGC model output, meaning that the model is validated for the savannah excluding fire regimes. However, in reality, fire is frequent in the savannah. Data on past fire events are available from the Moderate Resolution Imaging Spectroradiometer (MODIS) to provide the fire regimes of the model. As the field data-driven measurements of the burnt stands are influenced by fire in the savannah, this will therefore result in a Biome-BGC model validated for the impacts of fire on savannah ecology. The validated model can then be used to predict the savannah's flux dynamics under the fire scenarios expected with climate and/or human impact change.

Res Publica mängis topeltmängu / Risto Berendson

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Berendson, Risto, 1975-

2005-01-01

Res Publica jätkab koostööd Tallinna linnavalitsuses Reformierakonnaga. Tallinna linnapea Tõnis Paltsi sõnul oli paralleelsete läbirääkimiste pidamine Keskerakonna ja Reformierakonnaga Res Publica Tallinna piirkonna juhatuse valitud taktika. Kommenteerib Jaanus Piirsalu

Res Publica lihtliikmed tõrjuvad Veskimäge / Tuuli Koch

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Koch, Tuuli

2006-01-01

Ilmunud ka: Pärnu Postimees 17. okt. lk. 6. Isamaa ja Res Publica liidu peaministrikandidaadiks sai Mart Laar, kuid pinged erakondade sees kestavad edasi. Res Publica opositsioon toetab isamaaliitlast Mart Laari ja on Taavi Veskimäe vastu. Lisa: Otsitakse peaministrit

Biome depletion in conjunction with evolutionary mismatches could play a role in the etiology of neurofibromatosis 1.

Science.gov (United States)

Beales, Donna L

2015-04-01

Neurofibromatosis 1 (NF1) arises de novo in a striking 30-50% of cases, pointing toward an environmental etiology, though none has been clearly identified. The Biome Depletion Theory posits that the absence of mutualistic and commensal organisms within the human body coupled with modern lifestyle alterations may have profoundly deleterious effects, inclusive of immunologic derangement that is thought to result in allergy, atopy, and numerous autoimmune diseases. Biome depletion has been implicated as a factor in the etiology of both multiple sclerosis and autism spectrum disorders; biome reconstitution, i.e. replenishment of the biome with certain keynote species, is being used in the treatment of these and other autoimmune states. Neurofibromatosis 1 has been associated with allergy, various autoimmune states, multiple sclerosis, and autism. Recent research has posited that NF1, multiple sclerosis and autism may all arise from disturbances in the neural crest during gestation. This paper hypothesizes that there is indirect evidence that a highly inflammatory uterine state may precipitate epigenetic changes in vulnerable NF-related genes in the course of fetal development. The etiology of NF1 may lie in the absence of immunomodulation by commensal and mutualistic species once ubiquitously present in the environment, as well as through adoption of a modern lifestyle that contributes to chronic inflammation. Replenishment of helminths and other missing organisms to the human biome prior to conception as well as addressing nutritional status, psychological stress, and environmental exposures may prevent the development of NF1. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electricity market models and RES integration: The Greek case

International Nuclear Information System (INIS)

Simoglou, Christos K.; Biskas, Pandelis N.; Vagropoulos, Stylianos I.; Bakirtzis, Anastasios G.

2014-01-01

This paper presents an extensive analysis of the Greek electricity market for the next 7-year period (2014–2020) based on an hour-by-hour simulation considering five different RES technologies, namely wind, PV, small hydro, biomass and CHP with emphasis on PV integration. The impact of RES penetration on the electricity market operation is evaluated under two different models regarding the organization of the Greek wholesale day-ahead electricity market: a mandatory power pool for year 2014 (current market design) and a power exchange for the period 2015–2020 (Target Model). An integrated software tool is used for the simulation of the current and the future day-ahead market clearing algorithm of the Greek wholesale electricity market. Simulation results indicate the impact of the anticipated large-scale RES integration, in conjunction with each market model, on specific indicators of the Greek electricity market in the long-term. - Highlights: • Analysis of the Greek electricity market for the next 7-year period (2014–2020) based on hour-by-hour simulation. • Five different RES technologies are considered with emphasis on PV integration. • A power pool (for 2014) and a power exchange (for 2015–2020) are considered. • Various market indicators are used for the analysis of the impact of the RES integration on the Greek electricity market. • Two alternative tariff schemes for the compensation of the new ground-mounted PV units from 2015 onwards are investigated

Res Publica aukohus heidab juhtidele ette eetikavääratust / Toomas Mattson

Index Scriptorium Estoniae

Mattson, Toomas, 1970-

2002-01-01

Ilmunud ka: Põhjarannik ; Severnoje Poberezhje 22. november lk. 3;4. Res Publica aukohus arvab, et Res Publica juhid on rikkunud erakonna põhikirja, sisekorda ja eetikakoodeksit Kohtla-Järve juhtumi lahendamisel. Kohtla-Järvel sai linnapeaks riisumiskahtlusega uurimise all olev Valeri Korb tänu Keskerakonna ja Res Publica koalitsioonileppele. Kommenteerib Juhan Kivirähk

Res Publica Ida-Viru piirkond valis uue juhatuse / Erik Gamzejev

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Gamzejev, Erik, 1967-

2002-01-01

Ilmunud ka: Severnoje Poberezhje 4. dets. lk. 1. Res Publica Ida-Viru piirkonna üldkogul valiti uus juhatus, Vladimir Sarantsevi sõnul oli koosolek enamiku Kohtla-Järve osakonna liikmete arvates õigustühine. Res Publica peasekretäri Tõnis Konsi kommentaare

Environmental Dependence of Artifact CD Peaks of Chiral Schiff Base 3d-4f Complexes in Soft Mater PMMA Matrix

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Yu Okamoto

2011-10-01

Full Text Available Four chiral Schiff base binuclear 3d-4f complexes (NdNi, NdCu, GdNi, and GdCu have been prepared and characterized by means of electronic and CD spectra, IR spectra, magnetic measurements, and X-ray crystallography (NdNi. A so-called artifact peak of solid state CD spectra, which was characteristic of oriented molecules without free molecular rotation, appeared at about 470 nm. Magnetic data of the complexes in the solid state (powder and in PMMA cast films or solutions indicated that only GdCu preserved molecular structures in various matrixes of soft maters. For the first time, we have used the changes of intensity of artifact CD peaks to detect properties of environmental (media solid state (KBr pellets, PMMA cast films, concentration dependence of PMMA in acetone solutions, and pure acetone solution for chiral 3d-4f complexes (GdCu. Rigid matrix keeping anisotropic orientation exhibited a decrease in the intensity of the artifact CD peak toward negative values. The present results suggest that solid state artifact CD peaks can be affected by environmental viscosity of a soft mater matrix.

Carbon storage in permafrost and soils of the mammoth tundra-steppe biome: role in the global carbon budget

Science.gov (United States)

N.S. Zimov; S.A. Zimov; A.E. Zimova; G.M. Zimova; V.I. Chuprynin; F.S. Chapin

2009-01-01

During the Last Glacial Maximum (LGM), atmospheric CO2 concentration was 80-100 ppmv lower than in preindustrial times. At that time steppe-tundra was the most extensive biome on Earth. Some authors assume that C storage in that biome was very small, similar to today's deserts, and that the terrestrial carbon (C) reservoir increased at the...

Rationales for technology-specific RES support and their relevance for German policy

International Nuclear Information System (INIS)

Gawel, Erik; Lehmann, Paul; Purkus, Alexandra; Söderholm, Patrik; Witte, Katherina

2017-01-01

In order to achieve cost-effective RES-E deployment it is often argued that technology-neutral support schemes for renewables are indispensable. Against this background, RES-E support policies making widely use of technology differentiation in remuneration settings, e.g. across the EU, are frequently criticized from a theoretical point of view. However, in this paper we provide a systematic critique of the technology neutrality concept as a foundation for designing policy support schemes in the RES-E technology field. Specifically, the main objective of the paper is to scrutinize the arguments for technology-neutrality, and discuss three conceptual arguments for why technology-specific support schemes could in fact help minimize the societal costs of reaching future RES-E targets. We also briefly address different political economy concerns, which could constrain the choice of cost-effective policy support schemes, and that have to be taken into account for economic policy advice. For empirical illustration of the key arguments we refer to the case of German RES-E policy-making. The central conclusion from this paper is that technology-specific RES-E support schemes may generate significant economic benefits, particularly if technology markets work imperfectly and in second-best policy settings with additional non-internalized market failures. - Highlights: • Three theoretical cost-effectiveness reasons for technology-specific RES-E support. • German case study to show relevance of theoretical arguments for policy-making. • Political economy constraints to technology-neutral support are demonstrated. • Technology-specific RES-E support may generate significant economic benefits.

Reactivity continuum modeling of leaf, root, and wood decomposition across biomes

Science.gov (United States)

Koehler, Birgit; Tranvik, Lars J.

2015-07-01

Large carbon dioxide amounts are released to the atmosphere during organic matter decomposition. Yet the large-scale and long-term regulation of this critical process in global carbon cycling by litter chemistry and climate remains poorly understood. We used reactivity continuum (RC) modeling to analyze the decadal data set of the "Long-term Intersite Decomposition Experiment," in which fine litter and wood decomposition was studied in eight biome types (224 time series). In 32 and 46% of all sites the litter content of the acid-unhydrolyzable residue (AUR, formerly referred to as lignin) and the AUR/nitrogen ratio, respectively, retarded initial decomposition rates. This initial rate-retarding effect generally disappeared within the first year of decomposition, and rate-stimulating effects of nutrients and a rate-retarding effect of the carbon/nitrogen ratio became more prevalent. For needles and leaves/grasses, the influence of climate on decomposition decreased over time. For fine roots, the climatic influence was initially smaller but increased toward later-stage decomposition. The climate decomposition index was the strongest climatic predictor of decomposition. The similar variability in initial decomposition rates across litter categories as across biome types suggested that future changes in decomposition may be dominated by warming-induced changes in plant community composition. In general, the RC model parameters successfully predicted independent decomposition data for the different litter-biome combinations (196 time series). We argue that parameterization of large-scale decomposition models with RC model parameters, as opposed to the currently common discrete multiexponential models, could significantly improve their mechanistic foundation and predictive accuracy across climate zones and litter categories.

Presidendilossis pidutses ka üks Res Publica liige / Kadri Jakobson

Index Scriptorium Estoniae

Jakobson, Kadri, 1970-

2006-01-01

SL Õhtulehele presidendilossis toimunud noortepidudest rääkinud neiu on Res Publica liige, kuid tema sõnul pole tema parteiline kuuluvus pidudega seotud. Arvamust avaldavad Res Publica juhatuse liige Andreas Kaju, erakonna esimees Taavi Veskimägi, ERL-i pressiesindaja Agu Uudelepp jt.

Adapting the Biome-BGC Model to New Zealand Pastoral Agriculture: Climate Change and Land-Use Change

Science.gov (United States)

Keller, E. D.; Baisden, W. T.; Timar, L.

2011-12-01

We have adapted the Biome-BGC model to make climate change and land-use scenario estimates of New Zealand's pasture production in 2020 and 2050, with comparison to a 2005 baseline. We take an integrated modelling approach with the aim of enabling the model's use for policy assessments across broadly related issues such as climate change mitigation and adaptation, land-use change, and greenhouse gas projections. The Biome-BGC model is a biogeochemical model that simulates carbon, water, and nitrogen cycles in terrestrial ecosystems. We introduce two new 'ecosystems', sheep/beef and dairy pasture, within the existing structure of the Biome-BGC model and calibrate its ecophysiological parameters against pasture clipping data from diverse sites around New Zealand to form a baseline estimate of total New Zealand pasture production. Using downscaled AR4 climate projections, we construct mid- and upper-range climate change scenarios in 2020 and 2050. We produce land-use change scenarios in the same years by combining the Biome-BGC model with the Land Use in Rural New Zealand (LURNZ) model. The LURNZ model uses econometric approaches to predict future land-use change driven by changes in net profits driven by expected pricing, including the introduction of an emission trading system. We estimate the relative change in national pasture production from our 2005 baseline levels for both sheep/beef and dairy systems under each scenario.

Res Publica asus Reformierakonda Tallinna võimuliidust tõrjuma / Mirko Ojakivi

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Ojakivi, Mirko

2005-01-01

Res Publica Tallinna piirkonna juhatuse liikme Siim Roode sõnul teeb Res Publica Keskerakonna Tallinna piirkonna juhatusele ettepaneku koalitsiooniläbirääkimiste alustamiseks. Lisa: Paltsu ettekäändeks Unicom

Res Publica : umbusaldamine võib lõpetada senise koalitsiooni / Villy Paimets

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Paimets, Villy, 1972-

2005-01-01

Res Publica erakorraline volikogu avaldas toetust justiitsministrile ja andis peaministrile volitused lõpetada justiitsministri umbusaldamise korral senine koalitsioon ning alustada läbirääkimisi Isamaaliiduga. Lisa: Res Publica toetab Vaherit

Ticks parasitizing bats (Mammalia: Chiroptera in the Caatinga Biome, Brazil

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Hermes Ribeiro Luz

Full Text Available Abstract In this paper, the authors report ticks parasitizing bats from the Serra das Almas Natural Reserve (RPPN located in the municipality of Crateús, state of Ceará, in the semiarid Caatinga biome of northeastern Brazil. The study was carried out during nine nights in the dry season (July 2012 and 10 nights in the rainy season (February 2013. Only bats of the Phyllostomidae and Mormoopidae families were parasitized by ticks. The species Artibeus planirostris and Carolia perspicillata were the most parasitized. A total of 409 larvae were collected and classified into three genera: Antricola (n = 1, Nothoaspis (n = 1 and Ornithodoros (n = 407. Four species were morphologically identified as Nothoaspis amazoniensis, Ornithodoros cavernicolous, Ornithodoros fonsecai, Ornithodoros hasei, and Ornithodoros marinkellei. Ornithodoros hasei was the most common tick associated with bats in the current study. The present study expand the distributional ranges of at least three soft ticks into the Caatinga biome, and highlight an unexpected richness of argasid ticks inhabiting this arid ecosystem.

Aura-biomes are present in the water layer above coral reef benthic macro-organisms

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Kevin Walsh

2017-08-01

Full Text Available As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1 the coral Mussismilia braziliensis, (2 fleshy macroalgae (Stypopodium, Dictota and Canistrocarpus, (3 turf algae, and (4 the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific “aura-biome”. The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria, Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

Electronic and optoelectronic device applications based on ReS2

Science.gov (United States)

Liu, Erfu; Long, Mingsheng; Wang, Yaojia; Pan, Yiming; Ho, Chinghwa; Wang, Baigeng; Miao, Feng

Rhenium disulfide (ReS2) is a unique semiconducting TMD with distorted 1T structure and weak interlayer coupling. We have previously investigated its in-plane anisotropic property and electronic applications on FET and digital inverters. In this talk, we will present high responsivity phototransistors based on few-layer ReS2. Depending on the back gate voltage, source drain bias and incident optical light intensity, the maximum attainable photoresponsivity can reach as high as 88,600 A W-1, which is one of the highest value among individual two-dimensional materials with similar device structures. Such high photoresponsivity is attributed to the increased light absorption as well as the gain enhancement due to the existence of trap states in the few-layer ReS2 flakes. The existence of trap states is proved by temperature dependent transport measurements. It further enables the detection of weak signals. Our studies underscore ReS2 as a promising material for future electronic and sensitive optoelectronic applications.

Res Publica seisab vastu homse arvel elamisele / Siim Männik

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Männik, Siim

2005-01-01

Ilmunud ka: Vabariik (venek.) 30. august lk. 1. Res Publica koostab praegu kohalikeks valimisteks nimekirju. Erakond ei plaani korraldada mitte ühte üleriigilist valimiskampaaniat, vaid 120 kohalikku kampaaniat, peale selle on kavas üleriigiline n.-ö. foonikampaania. Lisa: Miks valida Res Publica? Vt. samas: Sisevalimised 1.-3. septembrini

Tropical rainforest biome of Biosphere 2. Structure, composition and results of the first 2 years of operation

Energy Technology Data Exchange (ETDEWEB)

Leigh, Linda S. [Systems Ecology and Energy Analysis Program, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL (United States); Burgess, Tony; Marino, Bruno D.V.; Wei, Yong Dan [Biosphere 2 Center, Inc. P.O. Box 689, Oracle, AZ (United States)

1999-06-01

The tropical rainforest biome in the Biosphere 2 mesocosm was managed with rainfall and temperature conditions to simulate a natural rainforest typical of the new world tropics. The establishment of the biome was based on the introduction of excessive numbers of species allowing self-organization of an ecologically unique rainforest. Over 282 species of plants from rainforest areas were planted within the topographically diverse rainforest biome (area of 1900 m{sup 2}, volume of 35,000 m{sup 3}), just before the Biosphere 2 closure in 1991. Approximately 61% of these species survived when counted in 1993, representing a plant species richness reduction to 172 species in 0.19 hectare. Rank order graphs show that a high diversity community resulted not unlike insular rainforests. The plants of the rainforest mesocosm, however, grew under anomalous conditions of soil (amended desert grassland soil), atmospheric composition (CO{sub 2} up to 4500 ppm by volume (ppmv)) and rainwater composition (high salinity and nutrients). Stem growth rates of a dominant canopy tree, Cecropia, were up to four times higher but had reduced diameter at breast height compared to natural counterparts. Human intervention in plant succession was also an important factor in shaping the ecology of the rainforest biome of Biosphere 2

Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland.

Science.gov (United States)

Scolforo, Henrique Ferraco; Scolforo, Jose Roberto Soares; Mello, Carlos Rogerio; Mello, Jose Marcio; Ferraz Filho, Antonio Carlos

2015-01-01

The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna.

The future distribution of the savannah biome: model-based and biogeographic contingency.

Science.gov (United States)

Moncrieff, Glenn R; Scheiter, Simon; Langan, Liam; Trabucco, Antonio; Higgins, Steven I

2016-09-19

The extent of the savannah biome is expected to be profoundly altered by climatic change and increasing atmospheric CO2 concentrations. Contrasting projections are given when using different modelling approaches to estimate future distributions. Furthermore, biogeographic variation within savannahs in plant function and structure is expected to lead to divergent responses to global change. Hence the use of a single model with a single savannah tree type will likely lead to biased projections. Here we compare and contrast projections of South American, African and Australian savannah distributions from the physiologically based Thornley transport resistance statistical distribution model (TTR-SDM)-and three versions of a dynamic vegetation model (DVM) designed and parametrized separately for specific continents. We show that attempting to extrapolate any continent-specific model globally biases projections. By 2070, all DVMs generally project a decrease in the extent of savannahs at their boundary with forests, whereas the TTR-SDM projects a decrease in savannahs at their boundary with aridlands and grasslands. This difference is driven by forest and woodland expansion in response to rising atmospheric CO2 concentrations in DVMs, unaccounted for by the TTR-SDM. We suggest that the most suitable models of the savannah biome for future development are individual-based dynamic vegetation models designed for specific biogeographic regions.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Author(s).

Gestão integrada de resíduos : o impacto ambiental

OpenAIRE

Oliveira, Rosário

2004-01-01

Faz-se uma introducão à politica de gestão integrada de resíduos para enquadrar a valorização de resíduos como política desejável para assegurar um desenvolvimento sustentado. Referem-se de seguida metodologias para avaliação do impacto ambiental da utilização de resíduos que possam ser usados como materiais de construção civil e obras públicas, ressalvando-se alguma falta de enquadramento legal.

Biome-BGC: Modeling Carbon Dynamics in Ponderosa Pine Stands (Law et al. 2003)

Data.gov (United States)

National Aeronautics and Space Administration — This archived model product contains the directions, executables, and procedures for running Biome-BGC, Version 4.1.2, to recreate the results of the following...

The progress of RES environment in the most recent member states of the EU

Energy Technology Data Exchange (ETDEWEB)

Patlitzianas, Konstantinos [Management and Decision Support Systems Lab (EPU-NTUA), School of Electrical and Computer Engineering, National Technical University of Athens, 9, Iroon Polytechniou str., 15773, Athens (Greece); Karagounis, Konstantinos [National and Kapodistrian University of Athens, Dental School, 2 Thivon Str., Goudi, 11527 Athens (Greece)

2011-02-15

The most recent EU member states seem to have important Renewable Energy Sources (RES) potential. However, they have serious structural difficulties in development and integration of RES policies. Indeed, the balanced development of RES between the member states is urgent today. The penetration of the RES in these member states is related to the existence of an appropriate environment (political, economical, social, and technological). The current paper is based on an analytical review and specific PEST analysis aiming to assess the current RES environment and the progress so far in each of these most recent EU members. (author)

Hi-Res scan mode in clinical MDCT systems: Experimental assessment of spatial resolution performance.

Science.gov (United States)

Cruz-Bastida, Juan P; Gomez-Cardona, Daniel; Li, Ke; Sun, Heyi; Hsieh, Jiang; Szczykutowicz, Timothy P; Chen, Guang-Hong

2016-05-01

The introduction of a High-Resolution (Hi-Res) scan mode and another associated option that combines Hi-Res mode with the so-called High Definition (HD) reconstruction kernels (referred to as a Hi-Res/HD mode in this paper) in some multi-detector CT (MDCT) systems offers new opportunities to increase spatial resolution for some clinical applications that demand high spatial resolution. The purpose of this work was to quantify the in-plane spatial resolution along both the radial direction and tangential direction for the Hi-Res and Hi-Res/HD scan modes at different off-center positions. A technique was introduced and validated to address the signal saturation problem encountered in the attempt to quantify spatial resolution for the Hi-Res and Hi-Res/HD scan modes. Using the proposed method, the modulation transfer functions (MTFs) of a 64-slice MDCT system (Discovery CT750 HD, GE Healthcare) equipped with both Hi-Res and Hi-Res/HD modes were measured using a metal bead at nine different off-centered positions (0-16 cm with a step size of 2 cm); at each position, both conventional scans and Hi-Res scans were performed. For each type of scan and position, 80 repeated acquisitions were performed to reduce noise induced uncertainties in the MTF measurements. A total of 15 reconstruction kernels, including eight conventional kernels and seven HD kernels, were used to reconstruct CT images of the bead. An ex vivo animal study consisting of a bone fracture model was performed to corroborate the MTF results, as the detection of this high-contrast and high frequency task is predominantly determined by spatial resolution. Images of this animal model generated by different scan modes and reconstruction kernels were qualitatively compared with the MTF results. At the centered position, the use of Hi-Res mode resulted in a slight improvement in the MTF; each HD kernel generated higher spatial resolution than its counterpart conventional kernel. However, the MTF along the

Res Publica toetus pole aastaga üle viie protsendi tõusnud / Tuuli Koch

Index Scriptorium Estoniae

Koch, Tuuli

2006-01-01

Emori jaanuarikuu küsitluse põhjal on 22 protsendiga suurim toetajaskond Keskerakonnal, Res Publica reiting on aasta aega püsinud viie ja kolme toetusprotsendi vahel. Vt. samas: Taavi Veskimägi. 2 küsimust. Diagrammid: Res Publica valiks riigikogusse tagasi vaid kolm protsenti valijaist; Toetus Res Publicale

Revisiting long-run relations in power markets with high RES penetration

International Nuclear Information System (INIS)

Gianfreda, Angelica; Parisio, Lucia; Pelagatti, Matteo

2016-01-01

Electricity generation from renewable energy resources (RES) has become increasingly significant to reach EU and emissions reduction targets. At the same time, one of the main EU policy goals has been the creation of a common internal energy market for Europe. In this paper, we focus on these two issues previously studied separately, considering their possible interactions. We first analyze the long-run relationship between day-ahead electricity prices and fuel prices (natural gas and coal) looking at two samples of years characterized by low and high RES penetration, then we explore the integration of EU markets. We show that the electricity–fuel nexus found over 2006–2008 changed dramatically over 2010–2014 for the majority of countries considered. In particular, the long-run dependence of electricity from gas and coal prices is much lower in recent years. Furthermore, our results confirm that the considered EU countries are becoming less integrated as RES-E increases. Our findings suggest that nationally implemented policies to support renewables are successful in increasing RES penetration, but they have lessened the linkage among EU markets, then making integration more difficult to obtain. - Highlights: •RES lower the intra-daily electricity dependence from coal and natural gas. •RES affect the EU wholesale electricity market integration, studied at hourly level. •Overlapping national and supranational policies tackle the achievement of EU targets. •Strong policy coordination is required to avoid that the “greens” promote the “dirtiest”.

A hierarchical analysis of terrestrial ecosystem model Biome-BGC: Equilibrium analysis and model calibration

Energy Technology Data Exchange (ETDEWEB)

Thornton, Peter E [ORNL; Wang, Weile [ORNL; Law, Beverly E. [Oregon State University; Nemani, Ramakrishna R [NASA Ames Research Center

2009-01-01

The increasing complexity of ecosystem models represents a major difficulty in tuning model parameters and analyzing simulated results. To address this problem, this study develops a hierarchical scheme that simplifies the Biome-BGC model into three functionally cascaded tiers and analyzes them sequentially. The first-tier model focuses on leaf-level ecophysiological processes; it simulates evapotranspiration and photosynthesis with prescribed leaf area index (LAI). The restriction on LAI is then lifted in the following two model tiers, which analyze how carbon and nitrogen is cycled at the whole-plant level (the second tier) and in all litter/soil pools (the third tier) to dynamically support the prescribed canopy. In particular, this study analyzes the steady state of these two model tiers by a set of equilibrium equations that are derived from Biome-BGC algorithms and are based on the principle of mass balance. Instead of spinning-up the model for thousands of climate years, these equations are able to estimate carbon/nitrogen stocks and fluxes of the target (steady-state) ecosystem directly from the results obtained by the first-tier model. The model hierarchy is examined with model experiments at four AmeriFlux sites. The results indicate that the proposed scheme can effectively calibrate Biome-BGC to simulate observed fluxes of evapotranspiration and photosynthesis; and the carbon/nitrogen stocks estimated by the equilibrium analysis approach are highly consistent with the results of model simulations. Therefore, the scheme developed in this study may serve as a practical guide to calibrate/analyze Biome-BGC; it also provides an efficient way to solve the problem of model spin-up, especially for applications over large regions. The same methodology may help analyze other similar ecosystem models as well.

The Economics of Root Distributions of Terrestrial Biomes in Response to Elevated CO2

Science.gov (United States)

Lu, M.; Hedin, L. O. O.

2017-12-01

Belowground root distributions of terrestrial biomes are central to understanding soil biogeochemical processes and land carbon sink. Yet models are thus far not able to predict root distributions across plant functional groups and major biomes, limiting our ability to predict the response of land systems to elevated CO2 concentration. Of particular concern is the apparent lack of stimulation of the aboveground carbon sink despite 30% increase of atmospheric CO2 over the past half-century, and despite the clear acceleration of the land carbon sink over the same period. This apparent discrepancy in land ecosystem response has led to the proposition that changes in belowground root dynamics might be responsible for the overlooked land sink. We here present a new modeling approach for predicting the response of root biomass and soil carbon storage to increased CO2. Our approach considers the first-principle mechanisms and tradeoffs by which plants and plant roots invest carbon to gain belowground resources, in collaboration with distinct root symbioses. We allow plants to locally compete for nutrients, with the ability to allocate biomass at different depths in the soil profile. We parameterized our model using an unprecedented global dataset of root traits, and validated our biome-level predictions with a recently updated global root biomass database. Our results support the idea that plants "dig deeper" when exposed to increased CO2, and we offer an economic-based mechanism for predicting the plant root response across soil conditions, plant functional groups and major biomes. Our model also recreates the observed responses across a range of free-air CO2 enrichment experiments, including a distinct response between plants associated with ectomycorrhizal and arbuscular mycorrhizal fungi. Most broadly, our findings suggest that roots may be increasingly important in the land carbon sink, and call for a greater effort to quantify belowground responses to elevated

Gerenciamento de resíduos odontológicos no serviço público

Directory of Open Access Journals (Sweden)

Lídia Regina da Costa Hidalgo

Full Text Available OBJETIVO: Verificar o processo de gerenciamento dos resíduos odontológicos do serviço público de saúde em 11 municípios brasileiros. MATERIAL E MÉTODO: Uma única pesquisadora realizou as visitas e as observações foram anotadas em um roteiro previamente elaborado e testado. RESULTADO: Foram visitadas 50 unidades de saúde, sendo que nenhuma apresentou cópia do plano de gerenciamento de resíduos. Do total de estabelecimentos, 62% realizavam a correta segregação dos resíduos no momento da sua geração. A presença de recipientes adequados a cada tipo de resíduo gerado no consultório odontológico foi observada em 74% dos estabelecimentos e, destes, 94% apresentavam capacidade adequada ao tipo de resíduo gerado. A identificação do tipo de resíduo nas embalagens plásticas bem como anotações identificando o estabelecimento gerador dos resíduos foram encontradas em 8% e 6%, respectivamente. Somente 21% dos estabelecimentos apresentavam locais apropriados, de acordo com as normas vigentes, para o armazenamento dos resíduos até que fosse feita a coleta externa. CONCLUSÃO: Constatou-se na presente pesquisa que a rotina adotada pela rede pública de saúde bucal, no que tange ao gerenciamento de resíduos de saúde, apresentou falhas.

Epitaxial growth of ReS2(001) thin film via deposited-Re sulfurization

Science.gov (United States)

Urakami, Noriyuki; Okuda, Tetsuya; Hashimoto, Yoshio

2018-02-01

In this paper, we present the formation of large-size rhenium disulfide (ReS2) films via the sulfurization of Re films deposited on sapphire substrates. The effects of sulfurization temperature and pressure on the crystal quality were investigated. A [001]-oriented single crystal of ReS2 films with 6 × 10 mm2 area was realized. By sulfurizing Re films at 1100 °C, ReS2 films with well-defined sharp interfaces to c-plane sapphire substrates could be formed. Below and above the sulfurization temperature of 1100 °C, incomplete sulfurization and film degradation were observed. The twofold symmetry of the monocrystalline in-plane structure composed of Re-Re bonds along with Re-S bonds pointed to a distorted 1T structure, indicating that this structure is the most stable atomic arrangement for ReS2. For a S/Re compositional ratio equal to or slightly lower than 2.0, characteristic Raman vibrational modes with the narrowest line widths were observed. The typical absorption peak of ReS2 can be detected at 1.5 eV.

Dynamique de fréquentation des grands mammifères dans une ...

African Journals Online (AJOL)

SARAH

31 juil. 2016 ... RÉSUMÉ. Objectifs : Dans le but de connaitre les animaux fréquentant les clairières (ou Baï) forestières au Gabon, une étude sur la fréquentation du Baï de Momba par les grands mammifères a été conduite durant la petite saison des pluies pendant deux mois du 19 février au 13 mars 2012. Méthodologie ...

Improved clonality detection in Hodgkin lymphoma using a semi-nested modification of the BIOMED-2 PCR assay for IGH and IGK rearrangements: A paraffin-embedded tissue study.

Science.gov (United States)

Han, Shusen; Masaki, Ayako; Sakamoto, Yuma; Takino, Hisashi; Murase, Takayuki; Iida, Shinsuke; Inagaki, Hiroshi

2018-05-01

The BIOMED-2 PCR protocols targeting IGH and IGK genes may be useful for detecting clonality in Hodgkin lymphoma (HL). The clonality detection rates, however, have not been very high with these methods using paraffin-embedded tumor sections. We previously described the usefulness of the semi-nested BIOMED-2 IGH assay in B-cell malignancies. In this study, we devised a novel semi-nested BIOMED-2 IGK assay. Employing 58 cases of classical HL, we carried out the standard BIOMED-2, BIOMED-2 followed by BIOMED-2 re-amplification, and BIOMED-2 followed by semi-nested BIOMED-2, all targeting IGH and IGK, using paraffin-embedded tissues. In both IGH and IGK assays, semi-nested assays yielded significantly higher clonality detection rates than the standard assays and re-amplification assays. Clonality was detected in 13/58 (22.4%) classical HL cases using the standard IGH/IGK assays while it was detected in 38/58 (65.5%) cases using semi-nested IGH/IGK assays. The detection rates were not associated with the HL subtypes, CD30-positive cell density, CD20-positive cell density, or Epstein-Barr virus (EBV) positivity. In conclusion, tumor clonality was detected in nearly two-thirds of classical HL cases using semi-nested BIOMED-2 IGH/IGK assays using paraffin tumor sections. These semi-nested assays may be useful when the standard IGH/IGK assays fail to detect clonality in histopathologically suspected HLs. © 2018 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

Extreme precipitation patterns and reductions of terrestrial ecosystem production across biomes

Science.gov (United States)

Yongguang Zhang; M. Susan Moran; Mark A. Nearing; Guillermo E. Ponce Campos; Alfredo R. Huete; Anthony R. Buda; David D. Bosch; Stacey A. Gunter; Stanley G. Kitchen; W. Henry McNab; Jack A. Morgan; Mitchel P. McClaran; Diane S. Montoya; Debra P.C. Peters; Patrick J. Starks

2013-01-01

Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more heavy rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of these climatic conditions on aboveground net primary...

RES-E Support Policies In The Baltic States: Development Aspect (Part I

Directory of Open Access Journals (Sweden)

Bobinaite V.

2015-02-01

Full Text Available Despite quite similar conditions (natural resources for electricity production from renewable energy sources (RES-E in three Baltic States (Estonia, Latvia and Lithuania, significant differences exist in these countries as to the RES-E production volume. In Latvia this volume is the highest, while in Estonia and Lithuania it is half as high. One of the factors that determine the RES-E production volumes is support policies, which in the Baltic States are different. The main objective of this work was to analyze and compare these support policies. The results have shown that for rapid RES-E development the most effective policy is to be market-oriented (as in Estonia, whereas for more stable development such policy should be producer-oriented (as in Lithuania.

Cities as Novel Biomes;Recognizing Urban Ecosystem Services as Anthropogenic

Directory of Open Access Journals (Sweden)

Stephanie ePincetl

2015-12-01

Full Text Available Urban Ecosystem Science is now an established science, arising along side the historic shift of humans to becoming in majority urban dwellers. In this Perspective I suggest there is a need to develop a new framework for UES as embedded in distinct urban biomes that can be classified by city-type and typologized. UES are largely the artifact of human decision making from what to plant where, to determining the urban infrastructure type in which UES will be placed. Developing urban typologies by climate zone, level of development, size and history will better enable the understanding of UES. I attempt to show the rise of the importance of nature, and of urban nature following the development of industrial city, and the importance of human intent in creating these urban ecosystems over time. If humans choose to manage cities through increasing UES, this will require coupled shifts, the shift in rules and regulations, goals and processes and shifts in urban form, infrastructure and function – socio-technical-ecological changes – driven by human decision-making. Such efforts will vary widely by city -- by urban biome.

The GAAS metagenomic tool and its estimations of viral and microbial average genome size in four major biomes.

Science.gov (United States)

Angly, Florent E; Willner, Dana; Prieto-Davó, Alejandra; Edwards, Robert A; Schmieder, Robert; Vega-Thurber, Rebecca; Antonopoulos, Dionysios A; Barott, Katie; Cottrell, Matthew T; Desnues, Christelle; Dinsdale, Elizabeth A; Furlan, Mike; Haynes, Matthew; Henn, Matthew R; Hu, Yongfei; Kirchman, David L; McDole, Tracey; McPherson, John D; Meyer, Folker; Miller, R Michael; Mundt, Egbert; Naviaux, Robert K; Rodriguez-Mueller, Beltran; Stevens, Rick; Wegley, Linda; Zhang, Lixin; Zhu, Baoli; Rohwer, Forest

2009-12-01

Metagenomic studies characterize both the composition and diversity of uncultured viral and microbial communities. BLAST-based comparisons have typically been used for such analyses; however, sampling biases, high percentages of unknown sequences, and the use of arbitrary thresholds to find significant similarities can decrease the accuracy and validity of estimates. Here, we present Genome relative Abundance and Average Size (GAAS), a complete software package that provides improved estimates of community composition and average genome length for metagenomes in both textual and graphical formats. GAAS implements a novel methodology to control for sampling bias via length normalization, to adjust for multiple BLAST similarities by similarity weighting, and to select significant similarities using relative alignment lengths. In benchmark tests, the GAAS method was robust to both high percentages of unknown sequences and to variations in metagenomic sequence read lengths. Re-analysis of the Sargasso Sea virome using GAAS indicated that standard methodologies for metagenomic analysis may dramatically underestimate the abundance and importance of organisms with small genomes in environmental systems. Using GAAS, we conducted a meta-analysis of microbial and viral average genome lengths in over 150 metagenomes from four biomes to determine whether genome lengths vary consistently between and within biomes, and between microbial and viral communities from the same environment. Significant differences between biomes and within aquatic sub-biomes (oceans, hypersaline systems, freshwater, and microbialites) suggested that average genome length is a fundamental property of environments driven by factors at the sub-biome level. The behavior of paired viral and microbial metagenomes from the same environment indicated that microbial and viral average genome sizes are independent of each other, but indicative of community responses to stressors and environmental conditions.

Modeling impacts of human footprint and soil variability on the potential distribution of invasive plant species in different biomes

Science.gov (United States)

Wan, Ji-Zhong; Wang, Chun-Jing; Yu, Fei-Hai

2017-11-01

Human footprint and soil variability may be important in shaping the spread of invasive plant species (IPS). However, until now, there is little knowledge on how human footprint and soil variability affect the potential distribution of IPS in different biomes. We used Maxent modeling to project the potential distribution of 29 IPS with wide distributions and long introduction histories in China based on various combinations of climatic correlates, soil characteristics and human footprint. Then, we evaluated the relative importance of each type of environmental variables (climate, soil and human footprint) as well as the difference in range and similarity of the potential distribution of IPS between different biomes. Human footprint and soil variables contributed to the prediction of the potential distribution of IPS, and different types of biomes had varying responses and degrees of impacts from the tested variables. Human footprint and soil variability had the highest tendency to increase the potential distribution of IPS in Montane Grasslands and Shrublands. We propose to integrate the assessment in impacts of human footprint and soil variability on the potential distribution of IPS in different biomes into the prevention and control of plant invasion.

Magnetic Surfaces, Thin Films, and Multilayers

Science.gov (United States)

1992-01-01

58 ACKNOWLEDGEMENTS. The authors of this paper would like to acknowledge many useful discussions with Mike Weinert. This work is supported in part by... Sharples , J. Mater. Res. 3, 856 (1988). 9. J.A. Thornton, J. Vac. Technol. A4, 3059 (1986). 10. O.K. Andersen, J. Madsen, U.K. Poulsen, 0. Jepsen, and J

Vegetation of the Hantam-Tanqua-Roggeveld subregion, South Africa Part 2: Succulent Karoo Biome related vegetation

Directory of Open Access Journals (Sweden)

Helga van der Merwe

2009-03-01

Full Text Available The Hantam-Tanqua-Roggeveld subregion lies within the Succulent Karoo Hotspot that stretches along the western side of the Republic of South Africa and Namibia. This project, carried out to document the botanical diversity in the Hantam-Tanqua-Roggeveld subregion, was part of a project identified as a priority during the SKEP (Succulent Karoo Ecosystem Programme initiative in this Hotspot. Botanical surveys were conducted in an area covering over three million hectares. Satellite images of the area and topocadastral, land type and geology maps were used to stratify the area into relatively homogeneous units. An analysis of the floristic data of 390 sample plots identified two major floristic units, i.e. the Fynbos Biome related vegetation and the Succulent Karoo Biome related vegetation. A description of the vegetation related to the Succulent Karoo Biome is presented in this article. Seven associations, 16 subassociations and several mosaic vegetation units, consisting of more than one vegetation unit, were identified and mapped. Various threats to the vegetation in the region were identified during the survey and are briefly discussed.

ANTIBACTERIAL POTENTIAL OF NATIVE PLANTS FROM THE CAATINGA BIOME AGAINST Staphylococcus spp. ISOLATES FROM SMALL RUMINANTS WITH MASTITIS

OpenAIRE

PEIXOTO, RODOLFO DE MORAES; SILVA, WELLINGTON ERASMO LIMA E; ALMEIDA, JACKSON ROBERTO GUEDES SILVA; BRANCO, ALEXSANDRO; COSTA, MATEUS MATIUZZI DA

2016-01-01

ABSTRACT The aim of the present study is to assess the antibacterial potential of plants from the Caatinga biome of the semi-arid region of Pernambuco, against Staphylococcus spp. isolates from cases of subclinical mastitis in small ruminants, such as goats and ewes. Ethanolic extracts of the following plants from the Caatinga biome were used: Encholirium spectabile Mart., Bromelia laciniosa Mart., Neoglaziovia variegata Mez., Amburana cearensis (Fr. Allem.) A. C. Smith, Hymenaea martiana Hay...

Sisetülides Res Publica heitis liidu Keskerakonnaga kõrvale / Urmas Seaver

Index Scriptorium Estoniae

Seaver, Urmas, 1973-

2005-01-01

Res Publica juhatus otsustas toetada senise koalitsiooni jätkamist Tallinnas. Res Publica ja Reformierakonna täiendatud koalitsioonileppest. Reformierakonna Tallinna piirkonna juhi Keit Pentuse hinnang võimutülile. Lisa: Võimuleppe lisa

The performances of standard and ResMed masks during bag-valve-mask ventilation.

Science.gov (United States)

Lee, Hyoung Youn; Jeung, Kyung Woon; Lee, Byung Kook; Lee, Seung Joon; Jung, Yong Hun; Lee, Geo Sung; Min, Yong Il; Heo, Tag

2013-01-01

A tight mask seal is frequently difficult to obtain and maintain during single-rescuer bag-valve-mask (BVM) ventilation. The ResMed mask (Bella Vista, NSW, Australia) is a continuous-positive-airway-pressure mask (CM) designed for noninvasive ventilation. In this study, we compared the ventilation performances of a standard mask (SM) and a ResMed CM using a simulation manikin in an out-of-hospital single-rescuer BVM ventilation scenario. Thirty emergency medical technicians (EMTs) performed two 2-minute attempts to ventilate a simulation manikin using BVM ventilation, alternatively, with the SM or the ResMed CM in a randomized order. Ventilation parameters including tidal volume and peak airway pressure were measured using computer analysis software connected to the simulation manikin. Successful volume delivery was defined as delivery of 440-540 mL of tidal volume in accord with present cardiopulmonary resuscitation guidelines. BVM ventilation using the ResMed CM produced higher mean (± standard deviation) tidal volumes (452 ± 50 mL vs. 394 ± 113 mL, p = 0.014) and had a higher proportion of successful volume deliveries (65.3% vs. 26.7%, p < 0.001) than that using the SM. Peak airway pressure was higher in BVM ventilation using the ResMed CM (p = 0.035). Stomach insufflation did not occur during either method. Twenty-nine of the participants (96.7%) preferred BVM ventilation using the ResMed CM. BVM ventilations using ResMed CM resulted in a significantly higher proportion of successful volume deliveries meeting the currently recommended range of tidal volume. Clinical studies are needed to determine the value of the ResMed CM for BVM ventilation.

Biossorção de azul de metileno utilizando resíduos agroindustriais

Directory of Open Access Journals (Sweden)

Andressa C. Honorato

2015-07-01

Full Text Available O presente trabalho avaliou a capacidade de adsorção do corante azul de metileno nos resíduos da palha de milho e da bainha do palmito pupunha in natura. A caracterização dos resíduos foi determinada utilizando-se a microscopia eletrônica de varredura e espectroscopia na região do infravermelho a qual indicou a presença de grupos carboxílicos, hidroxila e carbonila. O tempo necessário para que o sistema atingisse o equilíbrio para ambos os resíduos foi de 240 min, seguindo uma cinética descrita pelo modelo de pseudo-segunda ordem. A capacidade máxima de adsorção foi de 102,8 mg g-1 para o resíduo da palha de milho, seguindo o modelo de isoterma de Langmuir e 50,9 mg g-1 para o resíduo de palmito pupunha, sendo que o modelo que melhor se ajusta foi Freundlich. Desta forma, esses resíduos são promissores para a adsorção do corante azul de metileno em efluentes.

[Parameter sensitivity of simulating net primary productivity of Larix olgensis forest based on BIOME-BGC model].

Science.gov (United States)

He, Li-hong; Wang, Hai-yan; Lei, Xiang-dong

2016-02-01

Model based on vegetation ecophysiological process contains many parameters, and reasonable parameter values will greatly improve simulation ability. Sensitivity analysis, as an important method to screen out the sensitive parameters, can comprehensively analyze how model parameters affect the simulation results. In this paper, we conducted parameter sensitivity analysis of BIOME-BGC model with a case study of simulating net primary productivity (NPP) of Larix olgensis forest in Wangqing, Jilin Province. First, with the contrastive analysis between field measurement data and the simulation results, we tested the BIOME-BGC model' s capability of simulating the NPP of L. olgensis forest. Then, Morris and EFAST sensitivity methods were used to screen the sensitive parameters that had strong influence on NPP. On this basis, we also quantitatively estimated the sensitivity of the screened parameters, and calculated the global, the first-order and the second-order sensitivity indices. The results showed that the BIOME-BGC model could well simulate the NPP of L. olgensis forest in the sample plot. The Morris sensitivity method provided a reliable parameter sensitivity analysis result under the condition of a relatively small sample size. The EFAST sensitivity method could quantitatively measure the impact of simulation result of a single parameter as well as the interaction between the parameters in BIOME-BGC model. The influential sensitive parameters for L. olgensis forest NPP were new stem carbon to new leaf carbon allocation and leaf carbon to nitrogen ratio, the effect of their interaction was significantly greater than the other parameter' teraction effect.

Estimation of Carbon Flux of Forest Ecosystem over Qilian Mountains by BIOME-BGC Model

Science.gov (United States)

Yan, Min; Tian, Xin; Li, Zengyuan; Chen, Erxue; Li, Chunmei

2014-11-01

The gross primary production (GPP) and net ecosystem exchange (NEE) are important indicators for carbon fluxes. This study aims at evaluating the forest GPP and NEE over the Qilian Mountains using meteorological, remotely sensed and other ancillary data at large scale. To realize this, the widely used ecological-process-based model, Biome-BGC, and remote-sensing-based model, MODIS GPP algorithm, were selected for the simulation of the forest carbon fluxes. The combination of these two models was based on calibrating the Biome-BGC by the optimized MODIS GPP algorithm. The simulated GPP and NEE values were evaluated against the eddy covariance observed GPPs and NEEs, and the well agreements have been reached, with R2=0.76, 0.67 respectively.

Res Publica hakkab kaaluma Kohtla-Järve võimuliidust lahkumist / Erik Gamzejev

Index Scriptorium Estoniae

Gamzejev, Erik, 1967-

2002-01-01

Ilmunud ka: Severnoje Poberezhje 19. nov. lk. 1. Res Publica eestseisuse ettepanek Kohtla-Järve osakonnale lahkuda koalitsioonist. Osakonna juhatuse otsus esitada Hants Hint volikogu esimehe kandidaadiks. Res Publica liikmete käitumise arutelu aukohtus

Resúmenes Presentaciones de Pósteres

Directory of Open Access Journals (Sweden)

Editor Gabriel Vargas Arana

2015-12-01

Full Text Available En este artículo se pueden encontrar los resúmenes de las presentaciones de pósteres del III Congreso Latinoamericano de Plantas Medicinales, desarrollado del 12 al 14 de agosto de 2015 en la ciudad de Iquitos, Perú.

Determining the resilience of carbon dynamics in semi-arid biomes of the Southwestern US to severe drought and altered rainfall patterns

Science.gov (United States)

Litvak, M. E.; Krofcheck, D. J.; Hilton, T. W.; Fox, A. M.; Osuna, J. L.

2011-12-01

Water is critically important for biotic processes in semi-arid ecosystems and 2011 is developing as one of the most severe drought years on record for many parts of the Southwestern US. To quantify the impact of this severe drought on regional carbon and energy balance, we need a more detailed understanding of how water limitation alters ecosystem processes across a range of semi-arid biomes. We quantified the impact of severe drought and changes in both the quantity and distribution of precipitation on ecosystem biotic structure and function across the range of biomes represented in the NM elevation gradient network (desert grassland, creosote shrubland, juniper savanna, piñon-juniper woodland, ponderosa pine forest and subalpine mixed conifer forest). We compared how daily, seasonal and annual carbon and energy balance and their components in each of these biomes respond to changes in rainfall patterns using continuous measurements of carbon, water and energy exchange and associated measurements in each of these biomes during a 5 year period (2006-2011) that included a severe drought, and large variability in both winter precipitation and the timing and intensity of the monsoon. To understand the underlying mechanisms, we used time series of radiation absorbed by vegetation, surface albedo, soil moisture storage, phenology, gross primary productivity (GPP), ecosystem respiration (Re), and WorldView-2 images acquired pre- and post-monsoon in each of these biomes. In all of the biomes except the desert grassland site, the strength and timing of both winter and monsoon precipitation are important controls over carbon and energy dynamics in this region, though we see site-specific sensitivities across the elevation gradient. Over the past 5 years, carbon dynamics in the desert grassland site appears to be decoupled from winter precipitation. In addition, carbon dynamics in disturbed grassland and pinon-juniper ecosystems were more sensitive to severe drought than

The GAAS metagenomic tool and its estimations of viral and microbial average genome size in four major biomes.

Directory of Open Access Journals (Sweden)

Florent E Angly

2009-12-01

Full Text Available Metagenomic studies characterize both the composition and diversity of uncultured viral and microbial communities. BLAST-based comparisons have typically been used for such analyses; however, sampling biases, high percentages of unknown sequences, and the use of arbitrary thresholds to find significant similarities can decrease the accuracy and validity of estimates. Here, we present Genome relative Abundance and Average Size (GAAS, a complete software package that provides improved estimates of community composition and average genome length for metagenomes in both textual and graphical formats. GAAS implements a novel methodology to control for sampling bias via length normalization, to adjust for multiple BLAST similarities by similarity weighting, and to select significant similarities using relative alignment lengths. In benchmark tests, the GAAS method was robust to both high percentages of unknown sequences and to variations in metagenomic sequence read lengths. Re-analysis of the Sargasso Sea virome using GAAS indicated that standard methodologies for metagenomic analysis may dramatically underestimate the abundance and importance of organisms with small genomes in environmental systems. Using GAAS, we conducted a meta-analysis of microbial and viral average genome lengths in over 150 metagenomes from four biomes to determine whether genome lengths vary consistently between and within biomes, and between microbial and viral communities from the same environment. Significant differences between biomes and within aquatic sub-biomes (oceans, hypersaline systems, freshwater, and microbialites suggested that average genome length is a fundamental property of environments driven by factors at the sub-biome level. The behavior of paired viral and microbial metagenomes from the same environment indicated that microbial and viral average genome sizes are independent of each other, but indicative of community responses to stressors and

Variáveis biométricas da cana-de-açúcar fertilizada com resíduos orgânico e industrial e irrigada com água servida e potável Biometric variable of sugar cane fertilized with organic and industrial residues irrigated with potable and wastewater

Directory of Open Access Journals (Sweden)

Fabio O. de Nobile

2011-02-01

Full Text Available O uso agrícola de resíduos orgânicos e industriais é uma alternativa de aproveitamento como fertilizante e fonte de matéria orgânica ao solo. Neste sentido, o objetivo deste trabalho foi avaliar o uso do composto de lixo e biofertilizante como fonte de nutrientes, e o resíduo do processamento da bauxita como corretivo da acidez do solo, para a cultura da cana-de-açúcar (cana-planta, irrigada com água potável e servida. Para tanto foi conduzido experimento em vaso, utilizando-se de solo Argissolo Vermelho-Amarelo distrófico, cultivado com a variedade RB855536. Foram avaliadas variáveis biométricas da planta, tais como: altura de plantas, diâmetro do colmo, perfilhamento, número de folhas, matéria seca de raiz e parte aérea. Os dados obtidos evidenciaram que a qualidade da água de irrigação, potável ou servida, não influenciou as variáveis avaliadas. A aplicação de composto de lixo e de biofertilizante constituiu-se numa fonte eficiente de nutrientes para as plantas de cana-de-açúcar, mas é necessária a aplicação adicional de fertilizantes para a obtenção de produção de colmos, similar ao do tratamento com adubação mineral convencional. Já o resíduo do processamento da bauxita mostrou-se eficiente na correção da acidez, apresentando as variáveis físicas semelhantes ao tratamento com adubação mineral, com exceção da matéria seca de raiz.The agricultural use of organic and industrial residues is an alternative of exploitation with fertilization and source of organic matter to the soil. In this direction, the objective of this research was to evaluate the use of the urban solid waste and biofertilizer as nutrient source, and residue of the bauxite processing as agricultural liming materials of the soil for sugar cane (cane plant and culture yields, irrigated with potable water and wastewater. For in such an experiment in vase was lead, under Alfisol soil, cultivated with the variety RB855536. It had

Softball Games Bring NCI and Leidos Biomed Employees Together | Poster

Science.gov (United States)

NCI and Leidos Biomed employees took to the fields at Nallin Pond for the third annual slow-pitch softball games on August 26. The series attracted 54 employees who were divided into four teams, Red, Blue, Gray, and White, and they were cheered on by about 40 enthusiastic spectators. In the first set of games, the Gray team defeated the Blue team, 15–8, and the White team

BMRAT reviewer acknowledgement 2015

OpenAIRE

Lili Hami

2016-01-01

Contributing reviewers The editors of Biomedical Research and Therapy would like to thank all our reviewers who have contributed to the journal in Volume 2 (2015). [Biomed Res Ther 2016; 3(2.000): 528-532

Res Publicat on täna vaja rohkem kui kunagi varem / Taavi Veskimägi

Index Scriptorium Estoniae

Veskimägi, Taavi, 1974-

2005-01-01

Res Publica esimees seab erakonnale ülesandeks selgitada inimestele, et Res Publicat võib usaldada. Ta selgitab, et Res Publica parempoolne poliitika tähendab ka hoolimist nendest, kes ei saa endaga hakkama. Vt. samas: Viimased kampaaniapäevad

Res Publica nõuab veel üht abilinnapea kohta / Urmas Seaver

Index Scriptorium Estoniae

Seaver, Urmas, 1973-

2005-01-01

Tallinna linnapea Tõnis Palts on seisukohal, et Reformierakond surus koalitsiooni moodustamisel Res Publicale peale ebaõiglase vastutusvaldkondade jaotuse. Res Publica peasekretär Ott Lumi ei välista võimuliidu loomist Keskerakonnaga, kui Reformierakond järeleandmisi ei tee. ERL tegi ettepaneku kokku kutsuda erakondade ümarlaud. Vt. samas intervjuud Ott Lumiga

Valorisation par voie hydrométallurgique de Matières Premières Secondaires Valorization of Secondary Raw Materials by hydrometallurgical way

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Meux Eric

2013-11-01

Full Text Available Cet exposé s'intéressera à la récupération par voie hydrométallurgique de métaux contenus dans les Matières Premières Secondaires. Dans un premier temps seront abordées des généralités sur les Métaux Critiques, leur taux de recyclage et les gisements identifiés. Deux exemples de traitement seront ensuite développés : le traitement de catalyseurs d'hydrotraitement et le traitement de poudres métallifères issues de broyats d'accumulateurs par couplage électrolixiviation/électrodéposition. This talk will focus on the hydrometallurgical recovery of metals contained in secondary raw materials. At first, generalities about critical metals, their recycling rate and their identified supply will be addressed. Two examples of hydrometallurgical treatment will be then developed: the treatment of spent hydrotreating catalysts and the treatment of electrodes powders coming from grinding of spent batteries by coupling electroleaching/electrodeposition.

Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

Science.gov (United States)

Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A; Oomen, Roelof J; du Preez, Chris C; Ruppert, Jan C; Ewert, Frank

2014-01-01

Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be useful

Revisiting support policies for RES-E adulthood: Towards market compatible schemes

International Nuclear Information System (INIS)

Huntington, Samuel C.; Rodilla, Pablo; Herrero, Ignacio; Batlle, Carlos

2017-01-01

The past two decades of growth in renewable energy sources of electricity (RES-E) have been largely driven by out-of-market support policies. These schemes were designed to drive deployment on the basis of specific subsidies sustained in time to allow for the larger costs as well as to limit investor risk. While these policies have proven to be effective, the way they have been designed to date has led to costly market distortions that are becoming more difficult to ignore as penetrations reach unpreceded levels. In the context of this growing concern, we provide a critical analysis of the design elements of RES-E support schemes, focusing on how they affect this trade-off between promoting and efficiently integrating RES-E. The emphasis is on the structure of the incentive payment, which in the end turns to be the cornerstone for an efficient integration. We conclude that, while needed, a well-designed and further developed capacity-based support mechanism complemented with ex-post compensations defined for reference benchmark plants, such as the mechanism currently implemented in Spain, is an alternative with good properties if the major goal is truly market integration. The approach is robust to future developments in technology cost, performance and market penetration of RES-E. - Highlights: • Market distortions due to RES support mechanisms are becoming difficult to ignore. • This paper provides a critical analysis of the design elements of RES support schemes. • The emphasis is on the structure of the incentive, key for an efficient integration. • We argue in favor of a further developed capacity-based support mechanism. • The incentive should be combined with the design of a set of reference plants.

ResStock Analysis Tool | Buildings | NREL

Science.gov (United States)

Energy and Cost Savings for U.S. Homes Contact Eric Wilson to learn how ResStock can benefit your approach to large-scale residential energy analysis by combining: Large public and private data sources uncovered $49 billion in potential annual utility bill savings through cost-effective energy efficiency

Seasonal patterns of horse fly richness and abundance in the Pampa biome of southern Brazil.

Science.gov (United States)

Krüger, Rodrigo Ferreira; Krolow, Tiago Kütter

2015-12-01

Fluctuations in seasonal patterns of horse fly populations were examined in rainforests of tropical South America, where the climate is seasonal. These patterns were evaluated with robust analytical models rather than identifying the main factors that influenced the fluctuations. We examined the seasonality of populations of horse flies in fields and lowland areas of the Pampa biome of southern Brazil with generalized linear models. We also investigated the diversity of these flies and the sampling effort of Malaise traps in this biome over two years. All of the 29 species had clear seasonality with regard to occurrence and abundance, but only seven species were identified as being influenced by temperature and humidity. The sampling was sufficient and the estimated diversity was 10% more than observed. Seasonal trends were synchronized across species and the populations were most abundant between September and March and nearly zero in other months. While previous studies demonstrated that seasonal patterns in population fluctuations are correlated with climatic conditions in horse fly assemblages in South America rainforests, we show a clear effect of each factor on richness and abundance and the seasonality in the prevalence of horse fly assemblages in localities of the Pampa biome. © 2015 The Society for Vector Ecology.

Res, aliquid and nihil in Suárez and modern philosophy

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Leopoldo Prieto López

2013-07-01

Full Text Available the main relevant philosophical aspect in Suárez’s interpretation of the transcendentals is his doctrine of the notions res and aliquid. therefore, after analyzing the nature and the number of the transcendentals, as well as the relationship between them and the first principles, the article goes into a detailed historical analysis of the notions res and aliquid. With precedents in Avicenna and Duns Scotus, the ens is understood according to Suarez, negatively, as it is not nothing and, in such sense, it is something (aliquid and, positively, as it has got a quidditas and, therefore, it is res. the question of nothing (nihil is thus introduced into modern metaphysics. What’s more, the said interpretation is one of the fundamental conditions of the transformation of metaphysics in modern ontology. thus, in the post- Cartesian context of Schulmetaphysik, and its aliquitas (as non-nihil and its quiditative character (as res being presumed, the ens will be understood as an intelligible. through that, a Copernican revolution commenced that anticipated Kant himself.

Natural pomegranate juice reduces inflammation, muscle damage ...

African Journals Online (AJOL)

Ammar Achraf

Peer review under responsibility of Alexandria University Faculty of Medicine. ... Alexandria Journal of Medicine 54 (2018) 45–48 ..... Brocklehurst's textbook of geriatric medicine and gerontology. 7th ... Adv Biomed Res. ... Ann N Y Acad Sci.

Genetics Home Reference: keratoconus

Science.gov (United States)

... we stand? J Ophthalmol. 2014;2014:641708. doi: 10.1155/2014/641708. Epub 2014 Aug 28. Review. Citation ... keratoconus. Biomed Res Int. 2015;2015:795738. doi: 10.1155/2015/795738. Epub 2015 May 17. Review. Citation ...

CHAPTER 1

African Journals Online (AJOL)

Dr Olaleye

gastrointestinal tract, thereby increasing surface area and promoting rapid release of the ... Afr. J. Biomed. Res. Vol. 17, No.3 (September) 2014. Ayorinde and Odeniyi ..... fractal dimension of whey protein precipitates: implications for scale-up ...

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years

Science.gov (United States)

Marchant, R.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J. H.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.B.; Cleef, A.M.; Duivenvoorden, J.F.; Flenley, J.R.; De Oliveira, P.; Van Geel, B.; Graf, K.J.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.C.S.; Horn, S.P.; Islebe, G.A.; Kuhry, P.; Ledru, M.-P.; Mayle, F.E.; Leyden, B.W.; Lozano-Garcia, S.; Melief, A.B.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G. B.; Salgado-Labouriau, M. L.; Schasignbitz, F.; Schreve-Brinkman, E. J.; Wille, M.

2009-01-01

The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate

Modelling the distribution of 90Sr and 137Cs in the Mediterranean Sea (MTPII-MATER)

International Nuclear Information System (INIS)

Sanchez-Cabeza, J.A.; Ortega, M.; Fernandez, V.; Tintore, J.; Monaco, A.

1999-01-01

Within the frame of the MTPII-MATER project (MAST), the distribution of 90 Sr and 137 Cs in the Mediterranean Sea was modelled, as these radionuclides are useful tracers of water circulation. The Mediterranean Sea was divided into 81 boxes, corresponding to 21 regions, taking into account water mass circulation, bathymetry and data availability. Transfer rates were obtained from the MOM model run under MEDMEX conditions. The model was run with realistic inputs, which included weapons global fallout, Chernobyl 137 Cs, nuclear industry and river runoff. It was observed that existing data are scarce, especially in the eastern Mediterranean. In general, model predictions agreed well with observations, showing maximum concentrations in surface waters and maxima due to global fallout ( 137 Cs and 90 Sr) and to the Chernobyl accident ( 137 Cs only). (author)

In vivo study on the biocompatibility of chitosan-hydroxyapatite film depending on degree of deacetylation.

Science.gov (United States)

Jeong, Ki-Jae; Song, Younseong; Shin, Hye-Ri; Kim, Ji Eun; Kim, Jeonghyo; Sun, Fangfang; Hwang, Dae-Youn; Lee, Jaebeom

2017-06-01

Chitosan, produced from chitin, is one of the polymers with promising applications in various fields. However, despite diverse research studies conducted on its biocompatibility, its uses are still limited. The main reason is the degree of deacetylation (DOD), which represents the proportion of deacetylated units in the polymer and is directly correlated with its biocompatibility property. In this article, the in vivo biocompatibility of three chitosan-hydroxyapatite composite films composed of chitosan with different DOD values was investigated by traditional biological protocols and novel optical spectroscopic analyses. The DOD of the chitosan obtained from three different manufacturers was estimated and calculated by Raman spectroscopy, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The chitosan with the higher DOD induced a higher incidence of inflammation in skin cells. The amino group density, biodegradability, and crystallinity of chitosan are the three possible factors that need to be considered when determining the biocompatibility of the films for in vivo application, as they led to complicated biological results, resulting in either better or worse inflammation even when using chitosan products with the same DOD. This basic study on the relationship between the DOD and inflammation is valuable for the development of further chitosan-based researches. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1637-1645, 2017. © 2017 Wiley Periodicals, Inc.

Bacterial transmission from lens storage cases to contact lenses-Effects of lens care solutions and silver impregnation of cases.

Science.gov (United States)

Vermeltfoort, Pit B J; Hooymans, Johanna M M; Busscher, Henk J; van der Mei, Henny C

2008-10-01

The killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For transmission studies, biofilms of Staphylococcus aureus 835 or Pseudomonas aeruginosa no. 3 were grown on lens storage cases and incubated with a contact lens in different multipurpose lens care solutions (Opti-Free(R)Express(R), ReNu(R) MultiPlus(R), and SoloCare Aquatrade mark) or 0.9% NaCl. In addition, planktonic bacteria were directly suspended in multipurpose solutions and their killing efficacies were determined. The numbers of transmitted live and dead bacteria on the lenses were measured using a combination of plate counting and fluorescence microscopy. The highest killing efficacies were shown by Opti-Free(R) Express(R) for planktonic as well as for biofilm bacteria. Silver impregnation of lens cases in combination with the prescribed solution increased the killing efficacy for P. aeruginosa in biofilms, whereas effects for S. aureus were minor. Lowest numbers of live and dead bacteria were transmitted to a lens in Opti-Free(R) Express(R) multipurpose solution, with no significant differences between lens types and no effects of silver impregnation. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008. (c) 2008 Wiley Periodicals, Inc.

Neurite extension and neuronal differentiation of human induced pluripotent stem cell derived neural stem cells on polyethylene glycol hydrogels containing a continuous Young's Modulus gradient.

Science.gov (United States)

Mosley, Matthew C; Lim, Hyun Ju; Chen, Jing; Yang, Yueh-Hsun; Li, Shenglan; Liu, Ying; Smith Callahan, Laura A

2017-03-01

Mechanotransduction in neural cells involves multiple signaling pathways that are not fully understood. Differences in lineage and maturation state are suggested causes for conflicting reports on neural cell mechanosensitivity. To optimize matrices for use in stem cell therapy treatments transplanting human induced pluripotent stem cell derived neural stem cells (hNSC) into lesions after spinal cord injury, the effects of Young's Modulus changes on hNSC behavior must be understood. The present study utilizes polyethylene glycol hydrogels containing a continuous gradient in Young's modulus to examine changes in the Young's Modulus of the culture substrate on hNSC neurite extension and neural differentiation. Changes in the Young's Modulus of the polyethylene glycol hydrogels was found to affect neurite extension and cellular organization on the matrices. hNSC cultured on 907 Pa hydrogels were found to extend longer neurites than hNSC cultured on other tested Young's Moduli hydrogels. The gene expression of β tubulin III and microtubule-associated protein 2 in hNSC was affected by changes in the Young's Modulus of the hydrogel. The combinatory method approach used in the present study demonstrates that hNSC are mechanosensitive and the matrix Young's Modulus should be a design consideration for hNSC transplant applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 824-833, 2017. © 2016 Wiley Periodicals, Inc.

In vitro study of stimulation effect on endothelialization by a copper bearing cobalt alloy.

Science.gov (United States)

Jin, Shujing; Qi, Xun; Wang, Tongmin; Ren, Ling; Yang, Ke; Zhong, Hongshan

2018-02-01

Endothelialization is an important process after stenting in coronary artery. Recovery of the injured site timely can reduce the neointima formation and platelet absorbance, leading to a lower risk of in-stent restenosis. Copper is known to be critical in vascular construction. Thus a combination of copper with stent materials is a meaningful attempt. A copper bearing L605-Cu cobalt alloy was prepared and its effect on human umbilical vein endothelial cells (HUVECs) was evaluated in vitro in this study. It was found that HUVECs attached and stretched better on the surface of L605-Cu compared with L605, and the apoptosis of cells was decreased simultaneously. The migration and tube formation of HUVECs were also enhanced by the extract of L605-Cu. Furthermore, L605-Cu increased the mRNA expression of VEGF in HUVECs significantly. However it had no effect on the secretion of NO or mRNA expression of eNOS. The result of blood clotting test indicated that L605-Cu had better blood compatibility. These results above have demonstrated that the L605-Cu alloy is promising to be a new stent material with function of accelerating endothelialization. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 561-569, 2018. © 2017 Wiley Periodicals, Inc.

Evaluation of chemical stability of polymers of XIENCE everolimus-eluting coronary stents in vivo by pyrolysis-gas chromatography/mass spectrometry.

Science.gov (United States)

Kamberi, Marika; Pinson, David; Pacetti, Stephen; Perkins, Laura E L; Hossainy, Syed; Mori, Hiroyoshi; Rapoza, Richard J; Kolodgie, Frank; Virmani, Renu

2017-09-07

The polymers poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(n-butyl methacrylate) (PBMA) are employed in manufacturing the XIENCE family of coronary stents. PBMA serves as a primer and adheres to both the stent and the drug coating. PVDF-HFP is employed in the drug matrix layer to hold the drug everolimus on the stent and control its release. Chemical stability of the polymers of XIENCE stents in the in-vivo environment was evaluated by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) detection. For this evaluation, XIENCE stents explanted from porcine coronary arteries and from human coronary artery specimens at autopsy after 2-4 and 5-7 years of implantation, respectively, were compared to freshly manufactured XIENCE stents (controls). The comparison of pyrograms of explanted stent samples and controls showed identical fragmentation fingerprints of polymers, indicating that PVDF-HFP and PBMA maintained their chemical integrity after multiple years of XIENCE coronary stent implantation. The findings of the present study demonstrate the chemical stability of PVDF-HFP and PBMA polymers of the XIENCE family of coronary stents in the in-vivo environment, and constitute a further proof of the suitability of PVDF-HFP as a drug carrier for the drug eluting stent applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Cellulose-based porous scaffold for bone tissue engineering applications: Assessment of hMSC proliferation and differentiation.

Science.gov (United States)

Demitri, Christian; Raucci, Maria Grazia; Giuri, Antonella; De Benedictis, Vincenzo Maria; Giugliano, Daniela; Calcagnile, Paola; Sannino, Alessandro; Ambrosio, Luigi

2016-03-01

Physical foaming combined with microwave-induced curing was used in this study to develop an innovative device for bone tissue regeneration. In the first step of the process, a stable physical foaming was induced using a surfactant (i.e. pluronic) as blowing agent of a homogeneous blend of Sodium salt of carboxymethylcellulose (CMCNa) and polyethylene glycol diacrylate (PEGDA700) solution. In the second step, the porous structure of the scaffold was chemically stabilized by radical polymerization induced by a homogeneous rapid heating of the sample in a microwave reactor. In this step 2,2-Azobis[2-(2-imidazolin-2 yl)propane]Dihydrochloride was used as thermoinitiator (TI). CMCNa and PEGDA were mixed with different blends to correlate the properties of final product with the composition. The chemical properties of each sample were evaluated by spectroscopy analysis ATR-IR (before and after curing) in order to maximize reaction yield, and optimize kinetic parameters (i.e. time curing, microwave power). The stability of the materials was evaluated in vitro by degradation test in Phosphate Buffered Saline. Biological analyses were performed to evaluate the effect of scaffold materials on cellular behavior in terms of proliferation and early osteogenic differentiation of human Mesenchymal Stem Cells. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 726-733, 2016. © 2015 Wiley Periodicals, Inc.

Novel fabrication method of the peritoneal dialysis filter using silk fibroin with urease fixation system.

Science.gov (United States)

Moon, Bo Mi; Choi, Myung-Jin; Sultan, Md Tipu; Yang, Jae Won; Ju, Hyung Woo; Lee, Jung Min; Park, Hyun Jung; Park, Ye Ri; Kim, Soo Hyeon; Kim, Dong Wook; Lee, Min Chae; Jeong, Ju Yeon; Lee, Ok Joo; Sung, Gun Yong; Park, Chan Hum

2017-10-01

During the last decade, there has been a great advance in the kidney dialysis system by wearable artificial kidney (WAK) system for end-stage renal disease patients. Uremic solute removal and water regeneration system are the most prerequisite for WAK to work properly. In this study, we designed a filtering membrane system by using immobilized urease silk fibroin filter and evaluated its comparative effectiveness with a PVDF filtering system in peritoneal dialysate regeneration system by urea removal efficacy. We evaluated this membrane's characteristic and performances by conducting SEM-EDX analyze, water-binding abilities and porosity test, removal abilities of urea, cytotoxicity assay and enzyme activity assay. Under the condition for optimization of urease, the percentage removal of urea was about 40% and 60% in 50 mg/dL urea solution by urease immobilized PVDF and silk fibroin scaffolds, respectively. The batch experimental result showed that immobilized filter removed more than 50% of urea in 50 mg/dL urea solution. In addition silk fibroin with urease filter removed 90 percent of urea in the peritoneal dialysate after 24 h filtration. We suggest that silk fibroin with urease fixation filter can be used more effectively for peritoneal dialysate regeneration system, which have hydrophilic property and prolonged enzyme activity. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2136-2144, 2017. © 2016 Wiley Periodicals, Inc.

Nanoporous biomaterials for uremic toxin adsorption in artificial kidney systems: A review.

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Cheah, Wee-Keat; Ishikawa, Kunio; Othman, Radzali; Yeoh, Fei-Yee

2017-07-01

Hemodialysis, one of the earliest artificial kidney systems, removes uremic toxins via diffusion through a semipermeable porous membrane into the dialysate fluid. Miniaturization of the present hemodialysis system into a portable and wearable device to maintain continuous removal of uremic toxins would require that the amount of dialysate used within a closed-system is greatly reduced. Diffused uremic toxins within a closed-system dialysate need to be removed to maintain the optimum concentration gradient for continuous uremic toxin removal by the dialyzer. In this dialysate regenerative system, adsorption of uremic toxins by nanoporous biomaterials is essential. Throughout the years of artificial kidney development, activated carbon has been identified as a potential adsorbent for uremic toxins. Adsorption of uremic toxins necessitates nanoporous biomaterials, especially activated carbon. Nanoporous biomaterials are also utilized in hemoperfusion for uremic toxin removal. Further miniaturization of artificial kidney system and improvements on uremic toxin adsorption capacity would require high performance nanoporous biomaterials which possess not only higher surface area, controlled pore size, but also designed architecture or structure and surface functional groups. This article reviews on various nanoporous biomaterials used in current artificial kidney systems and several emerging nanoporous biomaterials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1232-1240, 2017. © 2016 Wiley Periodicals, Inc.

Use of lecithin to control fiber morphology in electrospun poly (ɛ-caprolactone) scaffolds for improved tissue engineering applications.

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Coverdale, Benjamin D M; Gough, Julie E; Sampson, William W; Hoyland, Judith A

2017-10-01

We elucidate the effects of incorporating surfactants into electrospun poly (ɛ-caprolactone) (PCL) scaffolds on network homogeneity, cellular adherence and osteogenic differentiation. Lecithin was added with a range of concentrations to PCL solutions, which were electrospun to yield functionalized scaffolds. Addition of lecithin yielded a dose-dependent reduction in scaffold hydrophobicity, whilst reducing fiber width and hence increasing specific surface area. These changes in scaffold morphology were associated with increased cellular attachment of Saos-2 osteoblasts 3-h postseeding. Furthermore, cells on scaffolds showed comparable proliferation over 14 days of incubation to TCP controls. Through model-based interpretation of image analysis combined with gravimetric estimates of porosity, lecithin is shown to reduce scaffold porosity and mean pore size. Additionally, lecithin incorporation is found to reduce fiber curvature, resulting in increased scaffold specific elastic modulus. Low concentrations of lecithin were found to induce upregulation of several genes associated with osteogenesis in primary mesenchymal stem cells. The results demonstrate that functionalization of electrospun PCL scaffolds with lecithin can increase the biocompatibility and regenerative potential of these networks for bone tissue engineering applications. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2865-2874, 2017. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

When size matters: differences in demineralized bone matrix particles affect collagen structure, mesenchymal stem cell behavior, and osteogenic potential.

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Dozza, B; Lesci, I G; Duchi, S; Della Bella, E; Martini, L; Salamanna, F; Falconi, M; Cinotti, S; Fini, M; Lucarelli, E; Donati, D

2017-04-01

Demineralized bone matrix (DBM) is a natural, collagen-based, osteoinductive biomaterial. Nevertheless, there are conflicting reports on the efficacy of this product. The purpose of this study was to evaluate whether DBM collagen structure is affected by particle size and can influence DBM cytocompatibility and osteoinductivity. Sheep cortical bone was ground and particles were divided in three fractions with different sizes, defined as large (L, 1-2 mm), medium (M, 0.5-1 mm), and small (S, structure, with DBM-M being altered but not as much as DBM-S. DBM-M displayed a preferable trend in almost all biological characteristics tested, although all DBM particles revealed an optimal cytocompatibility. Subcutaneous implantation of DBM particles into immunocompromised mice resulted in bone induction only for DBM-M. When sheep MSC were seeded onto particles before implantation, all DBM particles were able to induce new bone formation with the best incidence for DBM-M and DBM-S. In conclusion, the collagen alteration in DBM-M is likely the best condition to promote bone induction in vivo. Furthermore, the choice of 0.5-1 mm particles may enable to obtain more efficient and consistent results among different research groups in bone tissue-engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1019-1033, 2017. © 2017 Wiley Periodicals, Inc.

Atomic force microscopy and nanoindentation investigation of polydimethylsiloxane elastomeric substrate compliancy for various sputtered thin film morphologies.

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Maji, Debashis; Das, Soumen

2018-03-01

Crack free electrically continuous metal thin films over soft elastomeric substrates play an integral part in realization of modern day flexible bioelectronics and biosensors. Under nonoptimized deposition conditions, delamination, and/or cracking of the top film as well as the underlying soft substrate hinders optimal performance of these devices. Hence it is very important to understand and control not only the various deposition factors like power, time, or deposition pressure but also investigate the various interfacial physics playing a critical role in assuring thin film adhesion and substrate compliancy. In the present study, various nanomechanical information of the underlying substrate, namely, crack profile, average roughness, Young's modulus, and adhesion force were studied for uncracked and cracked polydimethylsiloxane (PDMS) surfaces along with pristine and conventional plasma treated PDMS samples as control. Quantification of the above parameters were done using three-dimensional surface profiler, scanning electron microscopy, nanoindentation, and atomic force microscopy techniques to elucidate the modulus range, average roughness, and adhesion force. Comparative analysis with control revealed remarkable similarity between increased modulus values, increased surface roughness, and reduced adhesion force accounting for reduced substrate compliancy and resulting in film cracking or buckling which are critical for development of various bioflexible devices. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 725-737, 2018. © 2017 Wiley Periodicals, Inc.

Prevascularization of 3D printed bone scaffolds by bioactive hydrogels and cell co-culture.

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Kuss, Mitchell A; Wu, Shaohua; Wang, Ying; Untrauer, Jason B; Li, Wenlong; Lim, Jung Yul; Duan, Bin

2017-09-13

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated that 3D co-cultured ADMSC-HUVEC generated capillary-like networks within the porous 3D printed scaffold. The co-culture systems promoted in vitro vascularization, but had no significant effects on osteogenesis. The prevascularized constructs were subcutaneously implanted into nude mice to evaluate the in vivo vascularization capacity and the functionality of engineered vessels. The hydrogel systems facilitated microvessel and lumen formation and promoted anastomosis of vascular networks of human origin with host murine vasculature. These findings demonstrate the potential of prevascularized 3D printed scaffolds with anatomical shape for the healing of larger bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Nitinol: Tubing versus sputtered film - microcleanliness and corrosion behavior.

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Wohlschlögel, Markus; Lima de Miranda, Rodrigo; Schüßler, Andreas; Quandt, Eckhard

2016-08-01

Corrosion behavior and microcleanliness of medical-device grade Nitinol tubing (Nix Ti1- x , x = 0.51; outer diameter 7 mm, wall thickness 0.5 mm), drawn from various ingot qualities, are compared to the characteristics of sputtered Nitinol film material (Nix Ti1- x , x = 0.51; thickness 50 µm). Electropolished tubing half-shell samples are tested versus as-received sputtered film samples. Inclusion size distributions are assessed using quantitative metallography and corrosion behavior is investigated by potentiodynamic polarization testing in phosphate-buffered saline at body temperature. For the sputtered film samples, the surface chemistry is additionally analyzed employing Auger Electron Spectroscopy (AES) composition-depth profiling. Results show that the fraction of breakdowns in the potentiodynamic polarization test correlates with number and size of the inclusions in the material. For the sputtered Nitinol film material no inclusions were detectable by light microscopy on the one hand and no breakdowns were found in the potentiodynamic polarization test on the other hand. As for electropolished Nitinol, the sputtered Nitinol film material reveals Nickel depletion and an Oxygen-to-Titanium intensity ratio of ∼2:1 in the surface oxide layer, as measured by AES. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1176-1181, 2016. © 2015 Wiley Periodicals, Inc.

Applications of additive manufacturing in dentistry: A review.

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Bhargav, Aishwarya; Sanjairaj, Vijayavenkatraman; Rosa, Vinicius; Feng, Lu Wen; Fuh Yh, Jerry

2017-07-24

Additive manufacturing (AM) or 3D printing has been hailed as the third industrial revolution as it has caused a paradigm shift in the way objects have been manufactured. Conventionally, converting a raw material to a fully finished and assembled, usable product comprises several steps which can be eliminated by using this process as functional products can be created directly from the raw material at a fraction of the time originally consumed. Thus, AM has found applications in several sectors including automotive, aerospace, printed electronics, and healthcare. AM is increasingly being used in the healthcare sector, given its potential to fabricate patient-specific customized implants with required accuracy and precision. Implantable heart valves, rib cages, and bones are some of the examples where AM technologies are used. A vast variety of materials including ceramics, metals, polymers, and composites have been processed to fabricate intricate implants using 3D printing. The applications of AM in dentistry include maxillofacial implants, dentures, and other prosthetic aids. It may also be used in surgical training and planning, as anatomical models can be created at ease using AM. This article gives an overview of the AM process and reviews in detail the applications of 3D printing in dentistry. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Influence of oxygen levels on chondrogenesis of porcine mesenchymal stem cells cultured in polycaprolactone scaffolds.

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Rodenas-Rochina, Joaquin; Kelly, Daniel J; Gómez Ribelles, Jose Luis; Lebourg, Myriam

2017-06-01

Chondrogenesis of mesenchymal stem cells (MSCs) is known to be regulated by a number of environmental factors, including local oxygen levels. The hypothesis of this study is that the response of MSCs to hypoxia is dependent on the physical and chemical characteristics of the substrate used. The objective of this study was to explore how different modifications to polycaprolactone (PCL) scaffolds influenced the response of MSCs to hypoxia. PCL, PCL-hyaluronic acid (HA), and PCL-Bioglass ® (BG) scaffolds were seeded with MSCs derived from bone marrow and cultured for 35 days under normoxic or low oxygen conditions, and the resulting biochemical properties of the MSC laden construct were assessed. Low oxygen tension has a positive effect over cell proliferation and macromolecules biosynthesis. Furthermore, hypoxia enhanced the distribution of collagen and glycosaminoglycans (GAGs) deposition through the scaffold. On the other hand, MSCs displayed certain material dependent responses to hypoxia. Low oxygen tension had a positive effect on cell proliferation in BG and HA scaffolds, but only a positive effect on GAGs synthesis in PCL and HA scaffolds. In conclusion, hypoxia increased cell viability and expression of chondrogenic markers but the cell response was modulated by the type of scaffold used. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1684-1691, 2017. © 2017 Wiley Periodicals, Inc.

Resorbable bioactive ceramic for treatment of bone infection.

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El-Ghannam, Ahmed; Jahed, Kiarash; Govindaswami, Meera

2010-07-01

Polymethylmethacrylate (PMMA) beads have been widely used in the treatment of bone infection over the last three decades. Although PMMA does offer a mechanism to quickly and effectively administer a localized dose of antibiotic to the site of infection, its efficacy is limited by its nonresorbability and nonbioactivity. Resorbable bioactive silica-calcium phosphate nanocomposite (SCPC75) was investigated as a novel controlled release carrier of vancomycin for the treatment of osteomyelitis. SCPC75 particles adsorbed significantly higher amount of vancomycin compared with PMMA. Moreover, SCPC75 provided a sustained release kinetics of therapeutic dose of vancomycin up to 35 days. The novel resorbable ceramic was able to release 95.5% of the adsorbed drug in an average dose of 12 microg/mL/day over 480 h (35 days). In conjunction with the sustained drug release, a controlled dissolution rate that led to 40% mass loss of SCPC75 was observed. On the other hand, PMMA provided a sustained release of a therapeutic dose of vancomycin for 14 days after which minimal concentration of the drug was detected. Moreover, PMMA retained 32% of the drug adsorbed onto its surface. The SCPC-vancomycin implant can serve a dual function: provide a sustained therapeutic dose of antibiotic to eradicate infection and stimulate bone cell differentiation and new bone formation. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

Particle size modeling and morphology study of chitosan/gelatin/nanohydroxyapatite nanocomposite microspheres for bone tissue engineering.

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Bagheri-Khoulenjani, Shadab; Mirzadeh, Hamid; Etrati-Khosroshahi, Mohammad; Shokrgozar, Mohammad Ali

2013-06-01

In this study, nanocomposite microspheres based on chitosan/gelatin/nanohydroxyapatite were fabricated, and effects of the nanohydroxyapatite/biopolymer (chitosan/gelatin) weight ratio (nHA/P), stirring rate, chitosan concentration and biopolymer concentration on the particle size, and morphology of nanocomposite microspheres were investigated. Particle size of microspheres was modeled by design of experiments using the surface response method. Particle size, morphology of microspheres, and distribution of nanoparticles within the composite microspheres were evaluated using an optical microscope, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. X-ray diffraction and Fourier transform infrared spectroscopy were applied to study the physical and chemical characteristics of microspheres. Results showed that by modulating the nHA/P ratio, chitosan concentration, polymer concentration, and stirring rate, it is possible to fabricate microspheres in wide rages of particle size (5-150 μm). Analysis of variance confirmed that the modified quadratic model can be used to predict the particle size of nanocomposite microspheres within the design space. SEM studies showed that microspheres with different compositions had totally different morphologies from dense morphologies to porous ones. TEM images demonstrated that nanoparticles were distributed uniformly within the polymeric matrix. MTT assay and cell culture studies showed that microspheres with different compositions possessed good biocompatibility. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. Copyright © 2012 Wiley Periodicals, Inc.

In vitro and in vivo study of commercial calcium phosphate cement HydroSet™.

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Kent, Niall W; Blunn, Gordon; Karpukhina, Natalia; Davis, Graham; de Godoy, Roberta Ferro; Wilson, Rory M; Coathup, Melanie; Onwordi, Lyris; Quak, Wen Yu; Hill, Robert

2018-01-01

The commercial calcium phosphate cement, HydroSet™, was investigated in vitro, studying phase formation, compressive strength and setting time, followed by an ovine in vivo study to measure osseointegration, bone apposition and bone-to-graft contact. The X-ray diffraction and 31 P Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) results showed the initial formation of octacalcium phosphate and hydroxyapatite at one hour. Over 7 days the octacalcium phosphate transformed to apatite, which was the only crystalline phase of the cement at 28 days. This apatite phase is thought to be a calcium deficient apatite. In the scanning electron microscopy, histological images of 12-week ovine in vivo results showed a high degree of osseointegration, 92.5%. Compressive strength comparisons between in vitro and in vivo measurements showed a dramatic difference between the in vitro measurements (highest 25.4 MPa) and in vivo (95 MPa), attributed to bone ingrowth into the cement in vivo. To the best of our knowledge this is the first time phase evolution of HydroSet™ and the properties studied in vitro complement the in vivo evaluation of the cement in a publication. The significance of the new finding of initial formation of octacalcium phosphate in this cement is discussed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 21-30, 2018. © 2016 Wiley Periodicals, Inc.

Aerogels made of chitosan and chondroitin sulfate at high degree of neutralization: Biological properties toward wound healing.

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Concha, Miguel; Vidal, Alejandra; Giacaman, Annesi; Ojeda, Javier; Pavicic, Francisca; Oyarzun-Ampuero, Felipe A; Torres, César; Cabrera, Marcela; Moreno-Villoslada, Ignacio; Orellana, Sandra L

2018-02-09

In this study, highly neutralized, highly porous, and ultralight polymeric aerogels prepared from aqueous colloidal suspensions of chitosan (CS) and chondroitin sulfate (ChS) nanocomplexes, formulated as quasi-equimolar amounts of both, are described. These aerogels were designed as healing agents under the inspiration of minimizing the amount of matter applied to wounds, reducing the electrostatic potential of the material and avoiding covalent cross-linkers in order to decrease metabolic stress over wounds. Aerogels synthesized under these criteria are biocompatible and provide specific properties for the induction of wound healing. They do not affect neither the metabolic activity of cultured 3T3 fibroblasts nor the biochemical parameters of experimental animals, open wounds close significantly faster and, unlike control wounds, complete reepithelialization and scarring can be attained 14 days after surgery. Because of its hydration abilities, rapid adaptation to the wound bed and the early accelerator effect of wound closure, the CS/ChS aerogels appear to be functional inducers of the healing. Previous information show that CS/ChS aerogels improve wound bed quality, increase granulation tissue and have pain suppressive effect. CS/ChS aerogels are useful as safe, inexpensive and easy to handle materials for topical applications, such as skin chronic wounds. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Effects of the micro-nano surface topography of titanium alloy on the biological responses of osteoblast.

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Yin, Chengcheng; Zhang, Yanjing; Cai, Qing; Li, Baosheng; Yang, Hua; Wang, Heling; Qi, Hua; Zhou, Yanmin; Meng, Weiyan

2017-03-01

In clinical applications, osseointegration is essential for the long-term stability of dental implants. Inspired by the hierarchical structure of natural bone, we applied the electrochemical etching (EC) technique to form a micro-nano structure on a titanium alloy (Ti6Al4V) substrate, called EC surface. Sand blasting and acid etching (SLA) and machined (M) methods were employed to generate micro and smooth textures, respectively, as the control groups. The surface topographies of the three substrates were characterized using scanning electron microscopy (SEM). Then, human osteoblast-like cells (MG63) were cultured on substrates, and adhesion, proliferation, morphology, alkaline phosphatase activity (ALP), and gene expression levels of Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), osteopontin (OPN), and type I collagen (COLIA 1) were analyzed. MG63 cells cultured on the EC Ti alloy substrates displayed better cell adhesion, significant proliferation, and a higher production level of ALP, gene expressions of RUNX2, OCN, OPN and COLIA 1 (p < 0.01 or p < 0.05) compared with those of SLA and M substrates. These results indicate that the micro-nano structure fabricated by electrochemical etching method is beneficial for the biological functions of MG63 cells and may be a promising candidate in dental implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 757-769, 2017. © 2016 Wiley Periodicals, Inc.

Cultivation of human dermal fibroblasts and epidermal keratinocytes on keratin-coated silica bead substrates.

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Tan, Bee Yi; Nguyen, Luong T H; Kim, Hyo-Sop; Kim, Jae-Ho; Ng, Kee Woei

2017-10-01

Human hair keratin is promising as a bioactive material platform for various biomedical applications. To explore its versatility further, human hair keratin was coated onto monolayers of silica beads to produce film-like substrates. This combination was hypothesized to provide a synergistic effect in improving the biochemical properties of the resultant composite. Atomic force microscopy analysis showed uniform coatings of keratin on the silica beads with a slight increase in the resulting surface roughness. Keratin-coated silica beads had higher surface energy and relatively lower negative charge than those of bare silica beads. To investigate cell response, human dermal fibroblasts (HDFs), and human epidermal keratinocytes (HEKs) were cultured on the substrates over 4 days. Results showed that keratin coatings significantly enhanced the metabolic activity of HDFs and encouraged cell spreading but did not exert any significant effects on HEKs. HDF expression of collagen I was significantly more intense on the keratin-coated compared to the bare silica substrates. Furthermore, HDF secretion of various cytokines suggested that keratin coatings triggered active cell responses related to wound healing. Collectively, our study demonstrated that human hair keratin-coated silica bead monolayers have the potential to modulate HDF behavior in culture and may be exploited further. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2789-2798, 2017. © 2017 Wiley Periodicals, Inc.

Current practices in corrosion, surface characterization, and nickel leach testing of cardiovascular metallic implants.

Science.gov (United States)

Nagaraja, Srinidhi; Di Prima, Matthew; Saylor, David; Takai, Erica

2017-08-01

In an effort to better understand current test practices and improve nonclinical testing of cardiovascular metallic implants, the Food and Drug Administration (FDA) held a public workshop on Cardiovascular Metallic Implants: corrosion, surface characterization, and nickel leaching. The following topics were discussed: (1) methods used for corrosion assessments, surface characterization techniques, and nickel leach testing of metallic cardiovascular implant devices, (2) the limitations of each of these in vitro tests in predicting in vivo performance, (3) the need, utility, and circumstances when each test should be considered, and (4) the potential testing paradigms, including acceptance criteria for each test. In addition to the above topics, best practices for these various tests were discussed, and knowledge gaps were identified. Prior to the workshop, discussants had the option to provide feedback and information on issues relating to each of the topics via a voluntary preworkshop assignment. During the workshop, the pooled responses were presented and a panel of experts discussed the results. This article summarizes the proceedings of this workshop and background information provided by workshop participants. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. J Biomed Mater Res Part B: Appl Biomater, 105B: 1330-1341, 2017. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility.

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Le, Duc H T; Tsutsui, Yoko; Sugawara-Narutaki, Ayae; Yukawa, Hiroshi; Baba, Yoshinobu; Ohtsuki, Chikara

2017-09-01

We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and β-sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2475-2484, 2017. © 2017 Wiley Periodicals, Inc.

In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

Science.gov (United States)

Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

2017-06-01

Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly) n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746-1755, 2017. © 2017 Wiley Periodicals, Inc.

Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

International Nuclear Information System (INIS)

Chatelin, Simon; Bernal, Miguel; Deffieux, Thomas; Papadacci, Clément; Nahas, Amir; Boccara, Claude; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu; Flaud, Patrice

2014-01-01

Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305–11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original multimodality imaging characterization of this new transverse isotropic (TI) PVA hydrogel. Multiple properties were investigated using a large variety of techniques at different scales compared with an isotropic PVA hydrogel undergoing similar imaging and rheology protocols. The anisotropic mechanical (dynamic and static) properties were studied using supersonic shear wave imaging technique, full-field optical coherence tomography (FFOCT) strain imaging and classical linear rheometry using dynamic mechanical analysis. The anisotropic optical and ultrasonic spatial coherence properties were measured by FFOCT volumetric imaging and backscatter tensor imaging, respectively. Correlation of mechanical and optical properties demonstrates the complementarity of these techniques for the study of anisotropy on a multi-scale range as well as the potential of this TI phantom as fibrous tissue-mimicking phantom for shear wave elastographic applications. (paper)

Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

Science.gov (United States)

Chatelin, Simon; Bernal, Miguel; Deffieux, Thomas; Papadacci, Clément; Flaud, Patrice; Nahas, Amir; Boccara, Claude; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

2014-11-01

Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305-11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original multimodality imaging characterization of this new transverse isotropic (TI) PVA hydrogel. Multiple properties were investigated using a large variety of techniques at different scales compared with an isotropic PVA hydrogel undergoing similar imaging and rheology protocols. The anisotropic mechanical (dynamic and static) properties were studied using supersonic shear wave imaging technique, full-field optical coherence tomography (FFOCT) strain imaging and classical linear rheometry using dynamic mechanical analysis. The anisotropic optical and ultrasonic spatial coherence properties were measured by FFOCT volumetric imaging and backscatter tensor imaging, respectively. Correlation of mechanical and optical properties demonstrates the complementarity of these techniques for the study of anisotropy on a multi-scale range as well as the potential of this TI phantom as fibrous tissue-mimicking phantom for shear wave elastographic applications.

Preparation of chitosan/amino multiwalled carbon nanotubes nanocomposite beads for bilirubin adsorption in hemoperfusion.

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Zong, Wenhui; Chen, Jian; Han, Wenyan; Chen, Jie; Wang, Yue; Wang, Weichao; Cheng, Guanghui; Ou, Lailiang; Yu, Yaoting

2018-01-01

Chitosan-carbon nanotube composite beads combines the advantages of chitosan in forming a stable biocompatible framework and carbon nanotube that provide nanometer effects (high strength and high specific surface area etc.). In this study, chitosan/amino multiwalled carbon nanotubes (CS/AMWCNT) composite beads was prepared by phase-inversion method, in which CS and AMWCNT was crosslinked by ethylene glycol diglycidyl ether (EGDE). The CS/AMWCNT nanocomposite beads produced has been characterized by BET, SEM, TGA, and Raman spectroscopy which exhibited enhanced thermal stability due to the incorporation of AMWCNT. Mechanical test results showed that mechanical strength of the CS/AMWCNT composite beads was significantly enhanced when comparing to unmodified chitosan beads, the breakage percentage decreased from 34.1% to 0.67%. The adsorption capacity for bilirubin was measured in PBS and BSA solutions, and the CS/AMWCNT composite beads with 5 wt% AMWCNT showed much higher adsorption capacity (12.7 mg/g in PBS and 7.6 mg/g in BSA) to bilirubin than chitosan beads (8.5 mg/g in PBS and 4.2 mg/g in BSA). Our nanocomposite beads with excellent hemocompatibility has a high potential application in blood purification as an efficient adsorbent for bilirubin. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 96-103, 2018. © 2016 Wiley Periodicals, Inc.

The effect of riboflavin/UVA cross-linking on anti-degeneration and promoting angiogenic capability of decellularized liver matrix.

Science.gov (United States)

Xiang, Junxi; Liu, Peng; Zheng, Xinglong; Dong, Dinghui; Fan, Shujuan; Dong, Jian; Zhang, Xufeng; Liu, Xuemin; Wang, Bo; Lv, Yi

2017-10-01

Weak mechanical property and unstable degradation rate limited the application of decellularized liver matrix in tissue engineering. The aim of this study was to explore a new method for improving the mechanical properties, anti-degeneration and angiogenic capability of decellularized liver matrix. This was achieved by a novel approach using riboflavin/ultraviolet A treatment to induce collagen cross-linking of decellularized matrix. Histological staining and scanning electron microscope showed that the diameter of cross-linked fibers significantly increased compared with the control group. The average peak load and Young's modulus of decellularized matrix were obviously improved after cross-linking. Then we implanted the modified matrix into the rat hepatic injury model to test the anti-degeneration and angiogenic capability of riboflavin/UVA cross-linked decellularized liver scaffolds in vivo. The results indicated that cross-linked scaffolds degrade more slowly than those in the control group. In the experiment group, average microvessel density in the implanted matrix was higher than that in the control group since the first week after implantation. In conclusion, we initiated the method to improve the biomechanical properties of decellularized liver scaffolds by riboflavin/UVA cross-linking, and more importantly, its improvement on anti-degeneration and angiogenesis was identified. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2662-2669, 2017. © 2017 Wiley Periodicals, Inc.

Comparison of shape memory polymer foam versus bare metal coil treatments in an in vivo porcine sidewall aneurysm model.

Science.gov (United States)

Horn, John; Hwang, Wonjun; Jessen, Staci L; Keller, Brandis K; Miller, Matthew W; Tuzun, Egemen; Hartman, Jonathan; Clubb, Fred J; Maitland, Duncan J

2017-10-01

The endovascular delivery of platinum alloy bare metal coils has been widely adapted to treat intracranial aneurysms. Despite the widespread clinical use of this technique, numerous suboptimal outcomes are possible. These may include chronic inflammation, low volume filling, coil compaction, and recanalization, all of which can lead to aneurysm recurrence, need for retreatment, and/or potential rupture. This study evaluates a treatment alternative in which polyurethane shape memory polymer (SMP) foam is used as an embolic aneurysm filler. The performance of this treatment method was compared to that of bare metal coils in a head-to-head in vivo study utilizing a porcine vein pouch aneurysm model. After 90 and 180 days post-treatment, gross and histological observations were used to assess aneurysm healing. At 90 days, the foam-treated aneurysms were at an advanced stage of healing compared to the coil-treated aneurysms and showed no signs of chronic inflammation. At 180 days, the foam-treated aneurysms exhibited an 89-93% reduction in cross-sectional area; whereas coiled aneurysms displayed an 18-34% area reduction. The superior healing in the foam-treated aneurysms at earlier stages suggests that SMP foam may be a viable alternative to current treatment methods. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1892-1905, 2017. © 2016 Wiley Periodicals, Inc.

Gelatin/nano-hydroxyapatite hydrogel scaffold prepared by sol-gel technology as filler to repair bone defects.

Science.gov (United States)

Raucci, Maria Grazia; Demitri, Christian; Soriente, Alessandra; Fasolino, Ines; Sannino, Alessandro; Ambrosio, Luigi

2018-07-01

This study reports on the development of a scaffold with a gradient of bioactive solid signal embedded in the biodegradable polymer matrix by combining a sol-gel approach and freeze-drying technology. The chemical approach based on the sol-gel transition of calcium phosphates ensures the particles dispersion into the gelatin matrix and a direct control of interaction among COOH gelatin /Ca 2+ ions. Morphological analysis demonstrated that on the basis of the amount of inorganic component and by using specific process conditions, it is possible to control the spatial distribution of nanoparticles around the gelatin helix. In fact, methodology and formulations were able to discriminate between the different hydroxyapatite concentrations and their respective morphology. The good biological response represented by good cell attachment, proliferation and increased levels of alkaline phosphatase as an indicator of osteoblastic differentiation of human mesenchymal stem cells toward the osteogenic lineage, demonstrating the effect of bioactive solid signals on cellular behavior. Furthermore, the inhibition of reactive oxygen species production by composite materials predicted potential anti-inflammatory properties of scaffolds thus confirming their biocompatibility. Indeed, these interesting biological results suggest good potential application of this scaffold as filler to repair bone defects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2007-2019, 2018. © 2018 Wiley Periodicals, Inc.

Structural and biological properties of thermosensitive chitosan-graphene hybrid hydrogels for sustained drug delivery applications.

Science.gov (United States)

Saeednia, Leyla; Yao, Li; Berndt, Marcus; Cluff, Kim; Asmatulu, Ramazan

2017-09-01

Chitosan has the ability to make injectable thermosensitive hydrogels which has been highly investigated for drug delivery applications. The addition of nanoparticles is one way to increase the mechanical strength of thermosensitive chitosan hydrogel and subsequently and control the burst release of drug. Graphene nanoparticles have shown unique mechanical, optical and electrical properties which can be exploited for biomedical applications, especially in drug delivery. This study, have focused on the mechanical properties of a thermosensitive and injectable hybrid chitosan hydrogel incorporated with graphene nanoparticles. Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD) have been used for morphological and chemical characterization of graphene infused chitosan hydrogels. The cell viability and cytotoxicity of graphene-contained hydrogels were analyzed using the alamarBlue ® technique. In-vitro methotrexate (MTX) release was investigated from MTX-loaded hybrid hydrogels as well. As a last step, to evaluate their efficiency as a cancer treatment delivery system, an in vitro anti-tumor test was also carried out using MCF-7 breast cancer cell lines. Results confirmed that a thermosensitive chitosan-graphene hybrid hydrogel can be used as a potential breast cancer therapy system for controlled delivery of methotrexate. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2381-2390, 2017. © 2017 Wiley Periodicals, Inc.

Biocorrosion of 316LV steel used in oral cavity due to Desulfotomaculum nigrificans bacteria.

Science.gov (United States)

Mystkowska, Joanna; Ferreira, Jose A; Leszczyńska, Katarzyna; Chmielewska, Sylwia; Dąbrowski, Jan Ryszard; Wieciński, Piotr; Kurzydłowski, Krzysztof Jan

2017-01-01

Corrosion processes of metallic biomaterials in the oral cavity pose a significant limitation to the life and reliable functioning of dental materials. In this article, the influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of 316LV steel was assessed. After 14 and 28 days of contact of the material with the bacterial environment, the surfaces of the tested biomaterial were observed by means of confocal scanning laser microscopy, and their chemical composition was studied using X-Ray Photoelectron Spectrometry and a scanning transmission electron microscopy. Corrosive changes, the presence of sulfur (with atomic concentration of 0.5%) on the surface of the biomaterial and the presence of a thin oxide layer (thickness of ∼20 nm) under the surface of the steel were observed. This corrosion layer with significant size reduction of grains was characterized by an increased amount of oxygen (18% mas., p < 0.001) in comparison to untreated 316LV steel (where oxygen concentration - 10% mas.). Image analysis conducted using APHELION software indicated that corrosion pits took up ∼2.8% of the total tested surface. The greatest number of corrosion pits had a surface area within the range of 100-200 μm 2 . © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 222-229, 2017. © 2015 Wiley Periodicals, Inc.

In situ spray deposition of cell-loaded, thermally and chemically gelling hydrogel coatings for tissue regeneration.

Science.gov (United States)

Pehlivaner Kara, Meryem O; Ekenseair, Adam K

2016-10-01

In this study, the efficacy of creating cellular hydrogel coatings on warm tissue surfaces through the minimally invasive, sprayable delivery of thermoresponsive liquid solutions was investigated. Poly(N-isopropylacrylamide)-based (pNiPAAm) thermogelling macromers with or without addition of crosslinking polyamidoamine (PAMAM) macromers were synthesized and used to produce in situ forming thermally and chemically gelling hydrogel systems. The effect of solution and process parameters on hydrogel physical properties and morphology was evaluated and compared to poly(ethylene glycol) and injection controls. Smooth, fast, and conformal hydrogel coatings were obtained when pNiPAAm thermogelling macromers were sprayed with high PAMAM concentration at low pressure. Cellular hydrogel coatings were further fabricated by different spraying techniques: single-stream, layer-by-layer, and dual stream methods. The impact of spray technique, solution formulation, pressure, and spray solution viscosity on the viability of fibroblast and osteoblast cells encapsulated in hydrogels was elucidated. In particular, the early formation of chemically crosslinked micronetworks during bulk liquid flow was shown to significantly affect cell viability under turbulent conditions compared to injectable controls. The results demonstrated that sprayable, in situ forming hydrogels capable of delivering cell populations in a homogeneous therapeutic coating on diseased tissue surfaces offer promise as novel therapies for applications in regenerative medicine. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2383-2393, 2016. © 2016 Wiley Periodicals, Inc.

Construction of polylysine dendrimer nanocomposites carrying nattokinase and their application in thrombolysis.

Science.gov (United States)

Wu, Can; Gao, Chunmei; Lü, Shaoyu; Xu, Xiubin; Wen, Na; Zhang, Shaofei; Liu, Mingzhu

2018-02-01

Thrombotic disease has become one of the leading causes of mortality among humans globally. Nattokinase (NK), a novel thrombolytic agent, has attracted the attention of researchers. However, NK is a serine protease that is vulnerable to environmental effects resulting in its inactivation. In this study, polylysine dendrimer (PLLD) was synthesized through divergence-convergence method, and a series of NK/PLLD nanocomposites with different molar ratio was prepared. In addition, NK was successfully incorporated into the cores of PLLD G4 through hydrogen bonds and van der Waals forces. In NK/PLLD nanocomposites, when the molar ratio of NK to PLLD is 1:30, a high relative enzyme activity level (up to 117%) was achieved and was more stable at different temperatures and pH than free NK. In in vitro thrombolysis experiment, compared with free NK, NK/PLLD nanocomposites could control the release of NK. The thrombolysis rate of NK/PLLD nanocomposites reached 50% at 12 h, which can effectively avoid other complications such as hemorrhage. Interestingly, NK/PLLD nanocomposites with positive charge can penetrate into the negatively charged thrombus through electrostatic interaction, thus providing a good thrombolytic effect. Hemolysis and MTT experiments show that PLLD nanomaterials can serve as ideal carriers of protein drugs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 440-449, 2018. © 2017 Wiley Periodicals, Inc.

Hydrostatic pressure in combination with topographical cues affects the fate of bone marrow‐derived human mesenchymal stem cells for bone tissue regeneration

Science.gov (United States)

El Haj, Alicia J.

2017-01-01

Abstract Topographical and mechanical cues are vital for cell fate, tissue development in vivo, and to mimic the native cell growth environment in vitro. To date, the combinatory effect of mechanical and topographical cues as not been thoroughly investigated. This study investigates the effect of PCL nanofiber alignment and hydrostatic pressure on stem cell differentiation for bone tissue regeneration. Bone marrow‐derived human mesenchymal stem cells were seeded onto standard tissue culture plastic and electrospun random and aligned nanofibers. These substrates were either cultured statically or subjected to intermittent hydrostatic pressure at 270 kPa, 1 Hz for 60 min daily over 21 days in osteogenic medium. Data revealed higher cell metabolic activities for all mechanically stimulated cell culture formats compared with non‐stimulated controls; and random fibers compared with aligned fibers. Fiber orientation influenced cell morphology and patterns of calcium deposition. Significant up‐regulation of Collagen‐I, ALP, and Runx‐2 were observed for random and aligned fibers following mechanical stimulation; highest levels of osteogenic markers were expressed when hydrostatic pressure was applied to random fibers. These results indicate that fiber alignment and hydrostatic pressure direct stem cell fate and are important stimulus for tissue regeneration. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: A: 629–640, 2018. PMID:28984025

Brushite foams—the effect of Tween® 80 and Pluronic® F‐127 on foam porosity and mechanical properties

Science.gov (United States)

Montufar, Edgar B.; Engqvist, Håkan; Ginebra, Maria‐Pau; Persson, Cecilia

2016-01-01

Abstract Resorbable calcium phosphate based bone void fillers should work as temporary templates for new bone formation. The incorporation of macropores with sizes of 100 −300 µm has been shown to increase the resorption rate of the implant and speed up bone ingrowth. In this work, macroporous brushite cements were fabricated through foaming of the cement paste, using two different synthetic surfactants, Tween® 80 and Pluronic® F‐127. The macropores formed in the Pluronic samples were both smaller and less homogeneously distributed compared with the pores formed in the Tween samples. The porosity and compressive strength (CS) were comparable to previously developed hydroxyapatite foams. The cement foam containing Tween, 0.5M citric acid in the liquid, 1 mass% of disodium dihydrogen pyrophosphate mixed in the powder and a liquid to powder ratio of 0.43 mL/g, showed the highest porosity values (76% total and 56% macroporosity), while the CS was >1 MPa, that is, the hardened cement could be handled without rupture of the foamed structure. The investigated brushite foams show potential for future clinical use, both as bone void fillers and as scaffolds for in vitro bone regeneration. © 2015 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 67–77, 2016. PMID:25615405

Student award for outstanding research winner in the Ph.D. category for the 2017 society for biomaterials annual meeting and exposition, april 5-8, 2017, Minneapolis, Minnesota: Characterization of protein interactions with molecularly imprinted hydrogels that possess engineered affinity for high isoelectric point biomarkers.

Science.gov (United States)

Clegg, John R; Zhong, Justin X; Irani, Afshan S; Gu, Joann; Spencer, David S; Peppas, Nicholas A

2017-06-01

Molecularly imprinted polymers (MIPs) with selective affinity for protein biomarkers could find extensive utility as environmentally robust, cost-efficient biomaterials for diagnostic and therapeutic applications. In order to develop recognitive, synthetic biomaterials for prohibitively expensive protein biomarkers, we have developed a molecular imprinting technique that utilizes structurally similar, analogue proteins. Hydrogel microparticles synthesized by molecular imprinting with trypsin, lysozyme, and cytochrome c possessed an increased affinity for alternate high isoelectric point biomarkers both in isolation and plasma-mimicking adsorption conditions. Imprinted and non-imprinted P(MAA-co-AAm-co-DEAEMA) microgels containing PMAO-PEGMA functionalized polycaprolactone nanoparticles were net-anionic, polydisperse, and irregularly shaped. MIPs and control non-imprinted polymers (NIPs) exhibited regions of Freundlich and BET isotherm adsorption behavior in a range of non-competitive protein solutions, where MIPs exhibited enhanced adsorption capacity in the Freundlich isotherm regions. In a competitive condition, imprinting with analogue templates (trypsin, lysozyme) increased the adsorption capacity of microgels for cytochrome c by 162% and 219%, respectively, as compared to a 122% increase provided by traditional bulk imprinting with cytochrome c. Our results suggest that molecular imprinting with analogue protein templates is a viable synthetic strategy for enhancing hydrogel-biomarker affinity and promoting specific protein adsorption behavior in biological fluids. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1565-1574, 2017. © 2017 Wiley Periodicals, Inc.

Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

Science.gov (United States)

Kulikouskaya, Viktoryia I; Pinchuk, Sergei V; Hileuskaya, Kseniya S; Kraskouski, Aliaksandr N; Vasilevich, Irina B; Matievski, Kirill A; Agabekov, Vladimir E; Volotovski, Igor D

2018-03-22

Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

Mechanical properties, structure, bioadhesion, and biocompatibility of pectin hydrogels.

Science.gov (United States)

Markov, Pavel A; Krachkovsky, Nikita S; Durnev, Eugene A; Martinson, Ekaterina A; Litvinets, Sergey G; Popov, Sergey V

2017-09-01

The surface structure, biocompatibility, textural, and adhesive properties of calcium hydrogels derived from 1, 2, and 4% solutions of apple pectin were examined in this study. An increase in the pectin concentration in hydrogels was shown to improve their stability toward elastic and plastic deformation. The elasticity of pectin hydrogels, measured as Young's modulus, ranged from 6 to 100 kPa. The mechanical properties of the pectin hydrogels were shown to correspond to those of soft tissues. The characterization of surface roughness in terms of the roughness profile (Ra) and the root-mean-square deviation of the roughness profile (Rq) indicated an increased roughness profile for hydrogels depending on their pectin concentration. The adhesion of AU2% and AU4% hydrogels to the serosa abdominal wall, liver, and colon was higher than that of the AU1% hydrogel. The adhesion of macrophages and the non-specific adsorption of blood plasma proteins were found to increase as the pectin concentration in the hydrogels increased. The rate of degradation of all hydrogels was higher in phosphate buffered saline (PBS) than that in DMEM and a fibroblast cell monolayer. The pectin hydrogel was also found to have a low cytotoxicity. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2572-2581, 2017. © 2017 Wiley Periodicals, Inc.

Comparison of high-intensity sound and mechanical vibration for cleaning porous titanium cylinders fabricated using selective laser melting.

Science.gov (United States)

Seiffert, Gary; Hopkins, Carl; Sutcliffe, Chris

2017-01-01

Orthopedic components, such as the acetabular cup in total hip joint replacement, can be fabricated using porous metals, such as titanium, and a number of processes, such as selective laser melting. The issue of how to effectively remove loose powder from the pores (residual powder) of such components has not been addressed in the literature. In this work, we investigated the feasibility of two processes, acoustic cleaning using high-intensity sound inside acoustic horns and mechanical vibration, to remove residual titanium powder from selective laser melting-fabricated cylinders. With acoustic cleaning, the amount of residual powder removed was not influenced by either the fundamental frequency of the horn used (75 vs. 230 Hz) or, for a given horn, the number of soundings (between 1 and 20). With mechanical vibration, the amount of residual powder removed was not influenced by the application time (10 vs. 20 s). Acoustic cleaning was found to be more reliable and effective in removal of residual powder than cleaning with mechanical vibration. It is concluded that acoustic cleaning using high-intensity sound has significant potential for use in the final preparation stages of porous metal orthopedic components. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 117-123, 2017. © 2015 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

Response of duplex Cr(N)/S and Cr(C)/S coatings on 316L stainless steel to tribocorrosion in 0.89% NaCl solution under plastic contact conditions.

Science.gov (United States)

Sun, Y; Dearnley, P A; Mallia, Bertram

2017-08-01

Two duplex coatings, Cr(N)/S and Cr(C)/S, were deposited on 316 L stainless steel by magnetron sputtering. The effectiveness of these duplex coatings in improving the tribocorrosion behavior of medical alloys under elastic contact conditions has been demonstrated in a recent publication. The present work focused on the response of these duplex coatings to tribocorrosion under plastic contact conditions. Tribocorrosion tests were conducted in 0.89% NaCl solution at 37°C at an initial contact pressure of 740 MPa and under unidirectional sliding conditions for sliding duration up to 24 h. The results showed that during sliding in the corrosive solution, the duplex coatings were plastically deformed into the substrate to a depth about 1 μm. The Cr(C)/S duplex coating had sufficient ductility to accommodate the deformation without cracking, such that it was worn through gradually, leading to the gradual increase in open circuit potential (OCP) and coefficient of friction (COF). On the other hand, the Cr(N)/S duplex coating suffered from cracking at all tested potentials, leading to coating blistering after prolonged sliding at OCP and stable pit formation in the substrate beneath the coating at applied anodic potentials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1503-1513, 2017. © 2016 Wiley Periodicals, Inc.

Co-micellized Pluronic mixture with thermo-sensitivity and residence stability as an injectable tissue adhesion barrier hydrogel.

Science.gov (United States)

Oh, Se Heang; Kang, Jun Goo; Lee, Jin Ho

2018-01-01

Although the tissue adhesion which leads to various complications frequently occurs after surgery, the development of an ideal tissue adhesion barrier is still a challenge. In this study, a thermo-sensitive hydrogel, which can fulfill the essential requirements of tissue adhesion barrier (that is, ease of handling for surgeon, flowing down prevention after application, stable residence on the injury during wound healing, and no use of toxic additives), was developed using biocompatible polyethylene glycol-polypropylene glycol copolymers (Pluronic F127/F68/P123 mixture). From the in vitro cell culture and in vivo animal study, it was observed that the Pluronic mixtures showed sol-gel transition at approximately body temperature (for easy injection or coating on the injury site and flowing down prevention after application) and prolonged residence stability in aqueous environment (> ∼7 days for stable protection of injury tissues/organs during wound healing), and thus was highly effective for the prevention of tissue adhesion without adverse tissue responses. Based on these results, the Pluronic F127/F68/P123 mixture itself (without any additives) can be a good candidate as an injectable or coatable tissue adhesion barrier hydrogel applicable to various injury tissues in terms of ease of use, effectiveness, and safety. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 172-182, 2018. © 2016 Wiley Periodicals, Inc.

Poly(N-isopropylacrylamide) hydrogel/chitosan scaffold hybrid for three-dimensional stem cell culture and cartilage tissue engineering.

Science.gov (United States)

Mellati, Amir; Kiamahalleh, Meisam Valizadeh; Madani, S Hadi; Dai, Sheng; Bi, Jingxiu; Jin, Bo; Zhang, Hu

2016-11-01

Providing a controllable and definable three-dimensional (3D) microenvironment for chondrogenic differentiation of mesenchymal stem cells (MSCs) remains a great challenge for cartilage tissue engineering. In this work, poly(N-isopropylacrylamide) (PNIPAAm) polymers with the degrees of polymerization of 100 and 400 (NI100 and NI400) were prepared and the polymer solutions were introduced into the preprepared chitosan porous scaffolds (CS) to form hybrids (CSNI100 and CSNI400, respectively). SEM images indicated that the PNIPAAm gel partially occupied chitosan pores while the interconnected porous structure of chitosan was preserved. MSCs were incorporated within the hybrid and cell proliferation and chondrogenic differentiation were monitored. After 7-day incubation of the cell-laden constructs in a growth medium, the cell viability in CSNI100 and CSNI400 were 54 and 108% higher than that in CS alone, respectively. Glycosaminoglycan and total collagen contents increased 2.6- and 2.5-fold after 28-day culture of cell-laden CSNI400 in the chondrogenic medium. These results suggest that the hybrid structure composed of the chitosan porous scaffold and the well-defined PNIPAAm hydrogel, in particular CSNI400, is suitable for 3D stem cell culture and cartilage tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2764-2774, 2016. © 2016 Wiley Periodicals, Inc.

Chemistry-driven structural alterations in short-term retrieved ceramic-on-metal hip implants: Evidence for in vivo incompatibility between ceramic and metal counterparts.

Science.gov (United States)

Zhu, Wenliang; Pezzotti, Giuseppe; Boffelli, Marco; Chotanaphuti, Thanainit; Khuangsirikul, Saradej; Sugano, Nobuhiko

2017-08-01

Ceramic-on-metal (CoM) hip implants were reported to experience lower wear rates in vitro as compared to metal-on-metal (MoM) bearings, thus hinting metal-ion release at lower levels in vivo. In this article, we show a spectroscopic study of two short-term retrieval cases of zirconia-toughened alumina (ZTA) femoral heads belonging to CoM hip prostheses, which instead showed poor wear performances in vivo. Metal contamination and abnormally high fractions of tetragonal-to-monoclinic (t→m) polymorphic transformation of the zirconia phase could be found on both ZTA heads, which contrasted with the optimistic predictions of in vitro experiments. At the molecular scale, incorporation of metal ions into the ceramic lattices could be recognized as due to frictionally assisted phenomena occurring at the ceramic surface. Driven by abnormal friction, diffusion of metal ions induced lattice shrinkage in the zirconia phases, while residual stress fields became stored at the surface of the femoral head. Diffusional alterations destabilized the chemistry of the ceramic surface and resulted in an abnormal increase in t→m phase transformation in vivo. Frictionally driven metal transfer to the ceramic lattice thus hinders the in vivo performance of CoM prostheses. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1469-1480, 2017. © 2016 Wiley Periodicals, Inc.

In vivo evaluation of hybrid patches composed of PLA based copolymers and collagen/chondroitin sulfate for ligament tissue regeneration.

Science.gov (United States)

Pinese, Coline; Gagnieu, Christian; Nottelet, Benjamin; Rondot-Couzin, Capucine; Hunger, Sylvie; Coudane, Jean; Garric, Xavier

2017-10-01

Biomaterials for soft tissues regeneration should exhibit sufficient mechanical strength, demonstrating a mechanical behavior similar to natural tissues and should also promote tissues ingrowth. This study was aimed at developing new hybrid patches for ligament tissue regeneration by synergistic incorporation of a knitted structure of degradable polymer fibers to provide mechanical strength and of a biomimetic matrix to help injured tissues regeneration. PLA- Pluronic ® (PLA-P) and PLA-Tetronic ® (PLA-T) new copolymers were shaped as knitted patches and were associated with collagen I (Coll) and collagen I/chondroitine-sulfate (Coll CS) 3-dimensional matrices. In vitro study using ligamentocytes showed the beneficial effects of CS on ligamentocytes proliferation. Hybrid patches were then subcutaneously implanted in rats for 4 and 12 weeks. Despite degradation, patches retained strength to answer the mechanical physiological needs. Tissue integration capacity was assessed with histological studies. We showed that copolymers, associated with collagen and chondroitin sulfate sponge, exhibited very good tissue integration and allowed neotissue synthesis after 12 weeks in vivo. To conclude, PLA-P/CollCS and PLA-T/CollCS hybrid patches in terms of structure and composition give good hopes for tendon and ligament regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1778-1788, 2017. © 2016 Wiley Periodicals, Inc.

Composite porous scaffold of PEG/PLA support improved bone matrix deposition in vitro compared to PLA-only scaffolds.

Science.gov (United States)

Bhaskar, Birru; Owen, Robert; Bahmaee, Hossein; Wally, Zena; Sreenivasa Rao, Parcha; Reilly, Gwendolen C

2018-05-01

Controllable pore size and architecture are essential properties for tissue-engineering scaffolds to support cell ingrowth colonization. To investigate the effect of polyethylene glycol (PEG) addition on porosity and bone-cell behavior, porous polylactic acid (PLA)-PEG scaffolds were developed with varied weight ratios of PLA-PEG (100/0, 90/10, 75/25) using solvent casting and porogen leaching. Sugar 200-300 µm in size was used as a porogen. To assess scaffold suitability for bone tissue engineering, MLO-A5 murine osteoblast cells were cultured and cell metabolic activity, alkaline phosphatase (ALP) activity and bone-matrix production determined using (alizarin red S staining for calcium and direct red 80 staining for collagen). It was found that metabolic activity was significantly higher over time on scaffolds containing PEG, ALP activity and mineralized matrix production were also significantly higher on scaffolds containing 25% PEG. Porous architecture and cell distribution and penetration into the scaffold were analyzed using SEM and confocal microscopy, revealing that inclusion of PEG increased pore interconnectivity and therefore cell ingrowth in comparison to pure PLA scaffolds. The results of this study confirmed that PLA-PEG porous scaffolds support mineralizing osteoblasts better than pure PLA scaffolds, indicating they have a high potential for use in bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1334-1340, 2018. © 2018 Wiley Periodicals, Inc.

Himalayan uplift shaped biomes in Miocene temperate Asia: evidence from leguminous Caragana

Science.gov (United States)

Ming-Li Zhang; Xiao-Guo Xiang; Juan-Juan Xue; Stewart C. Sanderson; Peter W. Fritsch

2016-01-01

Caragana, with distinctive variation in leaf and rachis characters, exhibits three centers of geographic distribution, i.e., Central Asia, the Qinghai-Tibetan Plateau (QTP), and East Asia, corresponding to distinct biomes. Because Caragana species are often ecologically dominant components of the vegetation in these regions, it is regarded as a key taxon for...

Hierarchical architecture of ReS_2/rGO composites with enhanced electrochemical properties for lithium-ion batteries

International Nuclear Information System (INIS)

Qi, Fei; Chen, Yuanfu; Zheng, Binjie; He, Jiarui; Li, Qian; Wang, Xinqiang; Lin, Jie; Zhou, Jinhao; Yu, Bo; Li, Pingjian; Zhang, Wanli

2017-01-01

Highlights: • The ReS_2/rGO composites have been synthesized by a facile one-pot method. • The ReS_2/rGO composites exhibit hierarchical architecture. • The ReS_2/rGO composites deliver better electrochemical performances than ReS_2. • The enhanced performance is due to porous and conductive structure of ReS_2/rGO. - Abstract: Rhenium disulfide (ReS_2), a two-dimensional (2D) semiconductor, has attracted more and more attention due to its unique anisotropic electronic, optical, mechanical properties. However, the facile synthesis and electrochemical property of ReS_2 and its composite are still necessary to be researched. In this study, for the first time, the ReS_2/reduced graphene oxide (rGO) composites have been synthesized through a facile and one-pot hydrothermal method. The ReS_2/rGO composites exhibit a hierarchical, interconnected, and porous architecture constructed by nanosheets. As anode for lithium-ion batteries, the as-synthesized ReS_2/rGO composites deliver a large initial capacity of 918 mAh g"−"1 at 0.2 C. In addition, the ReS_2/rGO composites exhibit much better electrochemical cycling stability and rate capability than that of bare ReS_2. The significant enhancement in electrochemical property can be attributed to its unique architecture constructed by nanosheets and porous structure, which can allow for easy electrolyte infiltration, efficient electron transfer, and ionic diffusion. Furthermore, the graphene with high electronic conductivity can provide good conductive passageways. The facile synthesis approach can be extended to prepare other 2D transition metal dichalcogenides semiconductors for energy storage and catalytic application.

Selection of native trees for intercropping with coffee in the Atlantic Rainforest biome

NARCIS (Netherlands)

Souza, de H.N.; Cardoso, I.M.; Fernandes, J.M.; Garcia, F.C.P.; Bonfim, V.R.; Santos, A.C.; Carvalho, A.F.; Mendonca, E.S.

2010-01-01

A challenge in establishing agroforestry systems is ensuring that farmers are interested in the tree species, and are aware of how to adequately manage these species. This challenge was tackled in the Atlantic Rainforest biome (Brazil), where a participatory trial with agroforestry coffee systems

Remotely sensed vegetation phenology for describing and predicting the biomes of South Africa

CSIR Research Space (South Africa)

Wessels, Konrad J

2011-02-01

Full Text Available the distribution of the recently redefined biomes be predicted based on remotely sensed, phenology and productivity metrics? Ten-day, 1 km, NDVI AVHRR were analysed for the period 1985 to 2000. Phenological metrics such as start, end and length of the growing...

Guide to the literature on research in the grassland biome of South Africa

CSIR Research Space (South Africa)

Tainton, MN

1984-12-01

Full Text Available the development of an understanding of how these communities can best be managed to ensure their sustained producti¬vity, or indeed to increase their productivity. This publication serves to highlight the main work which has been undertaken in this biome...

Regulatory design for RES-E support mechanisms: Learning curves, market structure, and burden-sharing

International Nuclear Information System (INIS)

Batlle, C.; Pérez-Arriaga, I.J.; Zambrano-Barragán, P.

2012-01-01

Drawing from relevant experiences in power systems around the world, this paper offers a review of existing policy support mechanisms for RES-E, with a detailed analysis of their regulatory implications. While recent studies provide an account of current RES-E support systems, in this paper we focus on some of the impacts these mechanisms have on the overall energy market structure and its performance. Given the rising importance of RES-E in systems everywhere, these impacts should no longer be overlooked. - Highlights: ► This paper offers a critical review of RES-E support mechanisms and their regulatory implications. ► The discussion focuses on how the different schemes impact the performance of the energy markets. ► We propose to redesign of current RES-E mechanisms to optimize incentives and market performance. ► Our recommendation is also to gradually move from price-based mechanisms to auctions.

Copépodes, Cladocères et Rotifères du lac Sidi M'hamed Benali (Algérie Nord-Occidentale

Directory of Open Access Journals (Sweden)

Mohamed Ali Bouzidi

2010-03-01

Full Text Available En 2008, 33 espèces de Cladocères, Copépodes et Rotifères ont été observées dans le lac Sidi M'hamed Benali (contre 12 seulement en 1992.Les Copépodes dominent en mars, avril, juillet, août et septembre, avec respectivement des dominances (Do égales à : 56,6 %, 55,0 %, 55,0 %, 46,4 % et 90,0 %. Les Cladocères dominent en février (Do = 37,2 %, mai (Do = 47,4 % et décembre (Do = 48,6 %. Les Rotifères sont extrêmement abondants et présentent une large dominance en janvier (Do = 95,3 %. La population zooplanctonique est très faible en juillet et en août. Au cours de l'année le peuplement varie en fonction de la température, des conditions hydrologiques, de l'abondance de la nourriture et de la prédation par les poissons.In 2008, 33 species of Cladocers, Copepods and Rotifers have been observed in Sidi M’hamed Benali Lake (against only 12 species in 1992. The Copepods dominate in March, April, July, August and September, respectively with dominance (Do equal to 56.6 %, 55.0 %, 55.0 %, 46.4 % and 90.0 %. Cladocers dominated in February (Do = 37.2 %, May (Do = 47.4 % and December (Do = 48.6 %. The rotifers are extremely abundant and have a wide dominance in January (Do = 95.3%. The zooplankton population is very low in July and August. During the year, the population varies with temperature, water conditions, abundance of food and predation by fishes.

Res Publica tähistab sünnipäeva konverentsiga / Lauri Tankler

Index Scriptorium Estoniae

Tankler, Lauri

2003-01-01

Ilmunud ka: Võta Võim : na russkom jazõke 3. dets. lk. 3. Res Publica saab 2-aastaseks, mille puhul korraldatakse konverents "Riik ja Res Publica". Vt. samas: Selle aasta veebruaris said kuldmärgid

Análisis comparativo de distintas toolkits para el reconocimiento biométrico de personas mediante voz

OpenAIRE

Ruíz, Silvia; Miranda, Ernesto; Herlein, Mauro; Etchart, Graciela; Alvez, Carlos E.

2017-01-01

El objetivo de este trabajo es realizar un análisis comparativo de distintas toolkits para el reconocimiento biométrico de personas mediante voz. Hoy en día los sistemas de identificación de personas se han convertido en una necesidad para la sociedad. A medida que avanza la tecnología y la aplicación de la misma en entornos tanto de ocio como de seguridad, la evolución en desarrollo biométrico es muy grande. Los sistemas de identificación o verificación tradicionales (tarjetas o claves) se h...

The role of plant functional trade-offs for biodiversity changes and biome shifts under scenarios of global climatic change

Directory of Open Access Journals (Sweden)

B. Reu

2011-05-01

Full Text Available The global geographic distribution of biodiversity and biomes is determined by species-specific physiological tolerances to climatic constraints. Current vegetation models employ empirical bioclimatic relationships to predict present-day vegetation patterns and to forecast biodiversity changes and biome shifts under climatic change. In this paper, we consider trade-offs in plant functioning and their responses under climatic changes to forecast and explain changes in plant functional richness and shifts in biome geographic distributions.

The Jena Diversity model (JeDi simulates plant survival according to essential plant functional trade-offs, including ecophysiological processes such as water uptake, photosynthesis, allocation, reproduction and phenology. We use JeDi to quantify changes in plant functional richness and biome shifts between present-day and a range of possible future climates from two SRES emission scenarios (A2 and B1 and seven global climate models using metrics of plant functional richness and functional identity.

Our results show (i a significant loss of plant functional richness in the tropics, (ii an increase in plant functional richness at mid and high latitudes, and (iii a pole-ward shift of biomes. While these results are consistent with the findings of empirical approaches, we are able to explain them in terms of the plant functional trade-offs involved in the allocation, metabolic and reproduction strategies of plants. We conclude that general aspects of plant physiological tolerances can be derived from functional trade-offs, which may provide a useful process- and trait-based alternative to bioclimatic relationships. Such a mechanistic approach may be particularly relevant when addressing vegetation responses to climatic changes that encounter novel combinations of climate parameters that do not exist under contemporary climate.

Res Publica presidendikandidaatide nimed selguvad neljapäevaks / Rauno Veri, Urmo Kübar

Index Scriptorium Estoniae

Veri, Rauno, 1978-

2006-01-01

Res Publica, Isamaaliit, Reformierakond, SDE ja Keskerakond otsivad ühist presidendikandidaati, ainsa parlamendierakonnana ei osale läbirääkimistel Rahvaliit. Reformierakonna, SDE presidendikandidaatidest; Res Publica naiskogu ja Väärikate Kogu ühisavaldusest

Convergence in the temperature response of leaf respiration across biomes and plant functional types.

Science.gov (United States)

Heskel, Mary A; O'Sullivan, Odhran S; Reich, Peter B; Tjoelker, Mark G; Weerasinghe, Lasantha K; Penillard, Aurore; Egerton, John J G; Creek, Danielle; Bloomfield, Keith J; Xiang, Jen; Sinca, Felipe; Stangl, Zsofia R; Martinez-de la Torre, Alberto; Griffin, Kevin L; Huntingford, Chris; Hurry, Vaughan; Meir, Patrick; Turnbull, Matthew H; Atkin, Owen K

2016-04-05

Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration-temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead, we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates.

AJESMS Vol 9 2011 October 23 2012 final

African Journals Online (AJOL)

Owner

2011-10-23

Oct 23, 2011 ... African Journal of Educational Studies in Mathematics and Sciences Vol. ... alveolar re-circulation and gravity orientation are key factors in determining the ..... Comp. Biomed. Res. 3, pp 675-689. Pich, J. (1972). Theory of ...

Cardiovascular Small Heat Shock Protein HSPB7 Is a Kinetically Privileged Reactive Electrophilic Species (RES) Sensor.

Science.gov (United States)

Surya, Sanjna L; Long, Marcus J C; Urul, Daniel A; Zhao, Yi; Mercer, Emily J; EIsaid, Islam M; Evans, Todd; Aye, Yimon

2018-02-08

Small heat shock protein (sHSP)-B7 (HSPB7) is a muscle-specific member of the non-ATP-dependent sHSPs. The precise role of HSPB7 is enigmatic. Here, we disclose that zebrafish Hspb7 is a kinetically privileged sensor that is able to react rapidly with native reactive electrophilic species (RES), when only substoichiometric amounts of RES are available in proximity to Hspb7 expressed in living cells. Among the two Hspb7-cysteines, this RES sensing is fulfilled by a single cysteine (C117). Purification and characterizations in vitro reveal that the rate for RES adduction is among the most efficient reported for protein-cysteines with native carbonyl-based RES. Covalent-ligand binding is accompanied by structural changes (increase in β-sheet-content), based on circular dichroism analysis. Among the two cysteines, only C117 is conserved across vertebrates; we show that the human ortholog is also capable of RES sensing in cells. Furthermore, a cancer-relevant missense mutation reduces this RES-sensing property. This evolutionarily conserved cysteine-biosensor may play a redox-regulatory role in cardioprotection.

Res-Parity: Parity Violation in Inelastic scattering at Low Q2

International Nuclear Information System (INIS)

Paul Reimer; Peter Bosted; John Arrington; Hamlet Mkrtchyan; Xiaochao Zheng

2006-01-01

Parity violating electron scattering has become a well established tool which has been used, for example, to probe the Standard Model and the strange-quark contribution to the nucleon. While much of this work has focused on elastic scattering, the RES-Parity experiment, which has been proposed to take place at Jefferson Laboratory, would focus on inelastic scattering in the low-Q 2 , low-W domain. RES-Parity would search for evidence of quark-hadron duality and resonance structure with parity violation in the resonance region. In terms of parity violation, this region is essentially unexplored, but the interpretation of other high-precision electron scattering experiments will rely on a reasonable understanding of scattering at lower energy and low-W through the effects of radiative corrections. RES-Parity would also study nuclear effects with the weak current. Because of the intrinsic broad band energy spectrum of neutrino beams, neutrino experiments are necessarily dependent on an untested, implicit assumption that these effects are identical to electromagnetic nuclear effects. RES-Parity is a relatively straight forward experiment. With a large expected asymmetry (∼ 0.5 x 10 -4 ) these studies may be completed with in a relatively brief period

Distribution of costs induced by the integration of RES-E power

International Nuclear Information System (INIS)

Barth, Ruediger; Weber, Christoph; Swider, Derk J.

2008-01-01

This article focuses on the distribution of costs induced by the integration of electricity generation from renewable energy sources (RES-E). The treatment to distribute these costs on different market actors is crucial for its development. For this purpose, individual actors of electricity markets and several cost categories are identified. According to the defined cost structure, possible treatments to distribute the individual cost categories on different relevant actors are described. Finally, an evaluation of the cost distribution treatments based on an economic analysis is given. Economic efficiency recommends that clearly attributable (shallow) grid connection as well as (deep) grid costs are charged to the corresponding RES-E producer and that the RES-E producers are also charged the regulating power costs. However, deep grid integration costs should be updated to reflect evolving scarcities. Also regulating power costs should reflect actual scarcity and thus be symmetric and based on real-time prices, taking into account the overall system imbalance. Moreover, the time span between the closure of the spot market and actual delivery should be chosen as short as possible to enable accurate RES-E production forecasts

Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV.

Science.gov (United States)

Barros, Juliana Helena S; Xavier, Samanta Cristina C; Bilac, Daniele; Lima, Valdirene Santos; Dario, Maria Augusta; Jansen, Ana Maria

2017-08-01

Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species. Copyright © 2017. Published by Elsevier B.V.

Plant phylogeny as a window on the evolution of hyperdiversity in the tropical rainforest biome.

Science.gov (United States)

Eiserhardt, Wolf L; Couvreur, Thomas L P; Baker, William J

2017-06-01

I. II. III. IV. V. VI. VII. VIII. IX. References SUMMARY: Tropical rainforest (TRF) is the most species-rich terrestrial biome on Earth, harbouring just under half of the world's plant species in c. 7% of the land surface. Phylogenetic trees provide important insights into mechanisms underpinning TRF hyperdiversity that are complementary to those obtained from the fossil record. Phylogenetic studies of TRF plant diversity have mainly focused on whether this biome is an evolutionary 'cradle' or 'museum', emphasizing speciation and extinction rates. However, other explanations, such as biome age, immigration and ecological limits, must also be considered. We present a conceptual framework for addressing the drivers of TRF diversity, and review plant studies that have tested them with phylogenetic data. Although surprisingly few in number, these studies point to old age of TRF, low extinction and high speciation rates as credible drivers of TRF hyperdiversity. There is less evidence for immigration and ecological limits, but these cannot be dismissed owing to the limited number of studies. Rapid methodological developments in DNA sequencing, macroevolutionary analysis and the integration of phylogenetics with other disciplines may improve our grasp of TRF hyperdiversity in the future. However, such advances are critically dependent on fundamental systematic research, yielding numerous, additional, well-sampled phylogenies of TRF lineages. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Welcome to Biomedical Research and Therapy

OpenAIRE

Phuc Van Pham

2014-01-01

On behalf of the Laboratory of Stem Cell Research and Application (SCL) and the Biomedical Research and Therapy' editorial team, we would like to extend a warm welcome to you. [Biomed Res Ther 2014; 1(1.000): 1-1

Non-invasive markers of atherosclerosis and their correlation with ...

African Journals Online (AJOL)

McRoy

2014-07-26

Jul 26, 2014 ... Study of non- invasive markers in patients with type 2 diabetes mellitus. Int J Med Biomed Res ... hypertension, smoking, and alcohol intake were documented for .... The risk of general CVD and hard CVD was significantly ...

Mobilidade de metais pesados em solo tratado com resíduo siderúrgico ácido

Directory of Open Access Journals (Sweden)

N. M. B. Amaral Sobrinho

1998-06-01

Full Text Available Amostras do horizonte Bt de um Podzólico Vermelho-Amarelo (PV, predominante no aterro-piloto de resíduos industriais (ARSI da Companhia Siderúrgica Nacional (CSN, foram acondicionadas, em 1992, em colunas de vidro com 5,4 cm de diâmetro e 37 cm de altura. Sobre essas amostras de solo foram colocadas amostras de um resíduo ácido da CSN na proporção solo-resíduo de 4:1 (conforme a concepção básica do projeto do ARSI. Tal sistema resíduo-solo foi lixiviado com 50 volumes-poro de água deionizada, com pH 4,5, com o objetivo de avaliar a movimentação de Cr, Mn, Ni, Cu, Zn, Cd e Pb nas colunas. Depois da lixiviação, removeu-se o resíduo do topo das colunas, e seccionaram-se as amostras de solo em 4 partes iguais. Os metais pesados das amostras do resíduo e do solo foram extraídos seqüencialmente. 0 Pb, Cu e Cr mobilizados do resíduo ficaram retidos nos primeiros 5 cm da coluna de solo. 0 Zn, Mn, Ni e Cd tiveram aumento da concentração em profundidade. Nos efluentes das colunas com o resíduo, foram observadas concentrações de Mn e Ni bem superiores aos padrões permitidos pela Fundação Estadual de Engenharia do Meio Ambiente (FEEMA, 1985.

Epidemiology of Chronic Wasting Disease: PrP(res) Detection, Shedding, and Environmental Contamination

National Research Council Canada - National Science Library

Williams, Elizabeth S; Miller, Michael W; Lewis, Randolf V; Raisbeck, Merl F; Cook, Walter W

2004-01-01

.... The specific goals of these studies are to develop sensitive as says for PrP(exp res) as a marker for infectivity, and use these techniques to monitor the dynamics and modes of shedding of PrP(exp res...

Room temperature synthesis of ReS2 through aqueous perrhenate sulfidation

Science.gov (United States)

Borowiec, Joanna; Gillin, William P.; Willis, Maureen A. C.; Boi, Filippo S.; He, Y.; Wen, J. Q.; Wang, S. L.; Schulz, Leander

2018-02-01

In this study, a direct sulfidation reaction of ammonium perrhenate (NH4ReO4) leading to a synthesis of rhenium disulfide (ReS2) is demonstrated. These findings reveal the first example of a simplistic bottom-up approach to the chemical synthesis of crystalline ReS2. The reaction presented here takes place at room temperature, in an ambient and solvent-free environment and without the necessity of a catalyst. The atomic composition and structure of the as-synthesized product were characterized using several analysis techniques including energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The results indicated the formation of a lower symmetry (1Tʹ) ReS2 with a low degree of layer stacking.

Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

Directory of Open Access Journals (Sweden)

Anja Linstädter

Full Text Available Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs. Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses and two-trait PFTs (e.g. perennial grasses performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may

Res Publica jäi järjekordselt ilma mitmest nimekast liikmest / Tuuli Koch, Kärt Anvelt

Index Scriptorium Estoniae

Koch, Tuuli

2005-01-01

Oma lahkumiset Res Publicast teatasid erakonna esimene esimees Rein Taagepera, tema abikaasa Mare Taagepera, akadeemik Jaan Einasto ja 2002. aastal erakonna esimeheks kandideerinud Lauri Aaspõllu. Rein Taagepera põhjendas otsust Res Publica liikumisega paremtsentrist paremäärmusse. Lisa: Tuntud inimesi, kes seni Res Publicast lahkunud. Vt. samas lühiintervjuud Jaan Einastoga: Res Publica peab tegema koostööd

Calibration of a biome-biogeochemical cycles model for modeling the net primary production of teak forests through inverse modeling of remotely sensed data

Science.gov (United States)

Imvitthaya, Chomchid; Honda, Kiyoshi; Lertlum, Surat; Tangtham, Nipon

2011-01-01

In this paper, we present the results of a net primary production (NPP) modeling of teak (Tectona grandis Lin F.), an important species in tropical deciduous forests. The biome-biogeochemical cycles or Biome-BGC model was calibrated to estimate net NPP through the inverse modeling approach. A genetic algorithm (GA) was linked with Biome-BGC to determine the optimal ecophysiological model parameters. The Biome-BGC was calibrated by adjusting the ecophysiological model parameters to fit the simulated LAI to the satellite LAI (SPOT-Vegetation), and the best fitness confirmed the high accuracy of generated ecophysioligical parameter from GA. The modeled NPP, using optimized parameters from GA as input data, was evaluated using daily NPP derived by the MODIS satellite and the annual field data in northern Thailand. The results showed that NPP obtained using the optimized ecophysiological parameters were more accurate than those obtained using default literature parameterization. This improvement occurred mainly because the model's optimized parameters reduced the bias by reducing systematic underestimation in the model. These Biome-BGC results can be effectively applied in teak forests in tropical areas. The study proposes a more effective method of using GA to determine ecophysiological parameters at the site level and represents a first step toward the analysis of the carbon budget of teak plantations at the regional scale.

Riigikogu aseesimeeste valimine tekitas paksu verd : Res Publical riigikogu juhatuses kaks kohta / Katrin Pauts

Index Scriptorium Estoniae

Pauts, Katrin, 1977-

2005-01-01

Riigikogu aseesimeesteks valiti Res Publica liige Taavi Veskimägi ja Keskerakonna liige Toomas Varek. Opositsiooniparteil Res Publica on nüüd juhatuses kaks kohta. Erakondade juhtpoliitikute kommentaare

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years ago

Science.gov (United States)

Marchant, R.; Cleef, A.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.; Duivenvoorden, J.; Flenley, J.; De Oliveira, P.; Van Gee, B.; Graf, K.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.; Horn, S.; Kuhry, P.; Ledru, M.-P.; Mayle, F.; Leyden, B.; Lozano-Garcia, S.; Melief, A.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G.; Salgado-Labouriau, M.; Schabitz, F.; Schreve-Brinkman, E. J.; Wille, M.

2009-01-01

The biomisation method is used to reconstruct Latin American vegetation at 6000??500 and 18 000??1000 radiocarbon years before present ( 14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000??500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000??500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000??1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain

Recherche de marqueurs lipidiques aptes à montrer l’absence de tissus nerveux dans les matières premières des gélatines d’os

Directory of Open Access Journals (Sweden)

Combe Nicole

2002-09-01

Full Text Available La gélatine est fabriquée à partir de deux catégories de matières premières, dénommées « os lourds » et « os légers », obtenues après dégraissage, séchage, broyage, puis tamisage d’os frais de bœuf, à l’exclusion de matériaux à risques vis-à-vis de l’encéphalopathie spongiforme bovine (cerveaux, yeux, amygdales et moelle épinière. L’objectif de cette étude était d’identifier un ou plusieurs constituants lipidiques spécifiques des tissus nerveux, et principalement de la moelle épinière, permettant de vérifier l’absence de tissus nerveux dans les matières premières utilisées pour la fabrication de gélatine. Pour cela, la composition lipidique de la moelle épinière a été comparée à celle des matières premières de gélatine. La pertinence d’un paramètre (p, vis-à-vis d’une source donnée, a été évaluée par la valeur du facteur : F (p = [p]moelle épinière/[p] OS, qui est le rapport entre sa concentration dans les lipides de moelle épinière et celle dans la source osseuse considérée. Plus la valeur de F est élevée, plus le paramètre est pertinent. Trois paramètres ont été ciblés sur la base de leur caractère spécifique des tissus nerveux par rapport aux graisses d’os : (1 les phospholipides (PL; (2 les acides gras à très longues chaînes (AGTLC = 20:0 + 20:1 + 22:0 + 22:1 n-9 + 23:0 + 24:0 + 24:1 n-9 ; (3 les alcools gras, analysés sous la forme de dérivés diméthyl acétals (DMA. Eu égard aux matières premières servant à la fabrication de gélatine, la valeur de FPL varie de 8 à 15, celle de FAGTLC de 25 à 41. La valeur de FDMA est égale à 26 vis-à-vis des « os légers », elle est infiniment grande vis-à-vis des « os lourds » puisque, dans cette matière première, les DMA sont indétectables. Ainsi pour cette catégorie de matière première, le paramètre DMA s’avère le plus adapté pour détecter du matériel d’origine nerveuse (moelle épinière.

A new species of Andocaeculus (Acari, Caeculidae) from the Pampa biome, southern Brazil

OpenAIRE

Ana Paula Ott; Ricardo Ott

2014-01-01

A new caeculid species Andocaeculus caioi sp. nov. is described from Pampa biome in south Brazil. The species of this family are usually large and strong sclerotized mites with robust and spinulose legs I and II. Until now records of species for South America were known only from Chile and Argentina.

Ühendpartei Res Publica tiib oli häältekogumisel Isamaast pisut edukam

Index Scriptorium Estoniae

2007-01-01

Ühenderakonna Res Publica tiiva kandidaadid said Riigikogu valimistel umbes tuhat häält rohkem kui Isamaaliidu tiiva kandidaadid, samas oli IRL-i valimisnimekirjas Res Publica tiiva kandidaate ka mõne inimese võrra rohkem. Isamaaliidu edukaimad hääletoojad

Ressources minières en Afrique : Quelle réglementation pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Ressources minières en Afrique : Quelle réglementation pour le développement ? Couverture du livre Ressources minières en Afrique : Quelle réglementation pour le développement ? Directeur(s):. Bonnie Campbell. Maison(s) d'édition: Presses de l'Université du Québec, CRDI. 6 juillet 2009. ISBN : 9782760525214.

Resíduos de aves e suínos: Potencialidades

Directory of Open Access Journals (Sweden)

Tiago Luan Hachmann

2014-05-01

Full Text Available O crescimento intenso da população mundial aumenta a demanda por alimentos. As carnes de frango e de suíno são as fontes mais exploradas de proteína na alimentação humana. Porém, com os métodos intensivos de produção, esses sistemas tem gerado insatisfação quanto ao aspecto ambiental e tem sido questionados quanto à sua sustentabilidade. A disposição inadequada dos resíduos gerados nos criatórios de suínos e aves afeta diretamente a qualidade do meio ambiente e a saúde pública. Assim deve-se buscar alternativas para minimizar os impactos causados ao meio, melhorando o aproveitamento e destinação desses resíduos. A aplicação desses resíduos nas áreas de produção agrícola é favorável à, tendo em vista que são uma fonte de nutrientes de grande demanda pelas culturas. Além disso é uma forma sustentável para destinação dos resíduos, já que promove seu reaproveitamento de forma a não poluir o ambiente e com alto retorno econômico. Dessa forma é possível aliar preservação ambiental com progresso econômico, promovendo uma produção sustentável.

Unraveling the Raman Enhancement Mechanism on 1T'-Phase ReS2 Nanosheets.

Science.gov (United States)

Miao, Peng; Qin, Jing-Kai; Shen, Yunfeng; Su, Huimin; Dai, Junfeng; Song, Bo; Du, Yunchen; Sun, Mengtao; Zhang, Wei; Wang, Hsing-Lin; Xu, Cheng-Yan; Xu, Ping

2018-04-01

2D transition metal dichalcogenides materials are explored as potential surface-enhanced Raman spectroscopy substrates. Herein, a systematic study of the Raman enhancement mechanism on distorted 1T (1T') rhenium disulfide (ReS 2 ) nanosheets is demonstrated. Combined Raman and photoluminescence studies with the introduction of an Al 2 O 3 dielectric layer unambiguously reveal that Raman enhancement on ReS 2 materials is from a charge transfer process rather than from an energy transfer process, and Raman enhancement is inversely proportional while the photoluminescence quenching effect is proportional to the layer number (thickness) of ReS 2 nanosheets. On monolayer ReS 2 film, a strong resonance-enhanced Raman scattering effect dependent on the laser excitation energy is detected, and a detection limit as low as 10 -9 m can be reached from the studied dye molecules such as rhodamine 6G and methylene blue. Such a high enhancement factor achieved through enhanced charge interaction between target molecule and substrate suggests that with careful consideration of the layer-number-dependent feature and excitation-energy-related resonance effect, ReS 2 is a promising Raman enhancement platform for sensing applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Écuyères and "doing gender"

DEFF Research Database (Denmark)

Hedenborg, Susanna; Pfister, Gertrud Ursula

2012-01-01

masculinity and horsemanship conveys the impression that women had nothing to do with horses. This is true for many situations. The circus arena, however, seems to have been an exception as women could perform there. At the heart of the performances was not only equestrianism, but also the notion of gender......The purpose of this article is to analyse gender relations in equestrianism from the beginning of the 19th to the first decades of the 20th century. Focus will be on the female horse riding circus artists, the écuyères. The fact that women were circus riders at this time is interesting as in many....... It is even likely that ”doing gender” was an indispensable part of the show, as the allure of the écuyères depended on the embodiment and presentation of seemingly incompatible features: beauty, grace and femininity as well as mastery of an art that was a traditionally male domain....

Experience of the Canary Islands in the development of insular 100% RES systems and micro-grids

Energy Technology Data Exchange (ETDEWEB)

Piernavieja, Gonzalo; Suarez, Salvador; Henriquez, Daniel [Instituto Tecnologico de Canarias (Canary Islands Institute of Technology - ITC), Las Palmas, Gran Canaria (Spain). RandD Div.

2010-07-01

Given the mentioned circumstances, conventional energy planning in the Canary Islands is a very complex task. The Regional Energy Plan PECAN (2007-2015) tries to correct the existing critical situation setting, among others, the ambitious goal of >25% electricity from RES (mostly wind) for 2015. In parallel to this conventional energy planning, outstanding initiatives in the distributed generation field are underway. ITC vision is that the Canarian Archipelago, given its particular characteristics (insular systems of different sizes, abundant RES potential -different sources-, important natural and biodiversity heritage, etc.), are a laboratory for testing and demonstrating new energy technologies in real conditions, as well as their commercial implementation. These new technologies include energy storage (particularly for excess RES that cannot be absorbed by the grids), development of 100% energy self- sufficiency models (with exclusive use of RES) and micro-/minigrids with high RES penetration and RES forecasting, including advanced ICTs and sustainable mobility concepts (e.g. V2G technologies). Given the high conventional generation costs and the relatively low RES costs (wind electricity production cost is less than 0.03 Euro/kWh), the Canary Islands could in the short term achieve grid parity, and in this sense pioneer the change to a RES based energy system. Models tested on the islands could be exported or extrapolated to our islands, regions of developing countries and even other regions in continental Europe. (orig.)

The freezer defrosting: global warming and litter decomposition rates in cold biomes. Essay review.

NARCIS (Netherlands)

Aerts, R.

2006-01-01

1 Decomposition of plant litter, a key component of the global carbon budget, is hierarchically controlled by the triad: climate > litter quality > soil organisms. Given the sensitivity of decomposition to temperature, especially in cold biomes, it has been hypothesized that global warming will lead

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes

Directory of Open Access Journals (Sweden)

Fernanda Aparecida Nieri-Bastos

2014-04-01

Full Text Available Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul and from horses in the Cerrado biome (state of Piauí in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63 and 66.7% (2/3 of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Software quality assurance and software safety in the Biomed Control System

International Nuclear Information System (INIS)

Singh, R.P.; Chu, W.T.; Ludewigt, B.A.; Marks, K.M.; Nyman, M.A.; Renner, T.R.; Stradtner, R.

1989-01-01

The Biomed Control System is a hardware/software system used for the delivery, measurement and monitoring of heavy-ion beams in the patient treatment and biology experiment rooms in the Bevalac at the Lawrence Berkeley Laboratory (LBL). This paper describes some aspects of this system including historical background philosophy, configuration management, hardware features that facilitate software testing, software testing procedures, the release of new software quality assurance, safety and operator monitoring. 3 refs

Beyond the climate envelope: using trait filtering models to predict biome boundaries from plant physiology.

Science.gov (United States)

Fisher, R.; Hoffmann, W. A.; Muszala, S.

2014-12-01

The introduction of second-generation dynamic vegetation models - which simulate the distribution of light resources between plant types along the vertical canopy profile, and therefore facilitate the representation of plant competition explicitly - is a large increase in the complexity and fidelity with which the terrestrial biosphere is abstracted into Earth System Models. In this new class of model, biome boundaries are predicted as the emergent properties of plant physiology, and are therefore sensitive to the high-dimensional parameterizations of plant functional traits. These new approaches offer the facility to quantitatively test ecophysiological hypotheses of plant distribution at large scales, a field which remains surprisingly under-developed. Here we describe experiments conducted with the Community Land Model Ecosystem Demography component, CLM(ED), in which we reduce the complexity of the problem by testing how individual plant functional trait changes to control the location of biome boundaries between functional types. Specifically, we investigate which physiological trade-offs determine the boundary between frequently burned savanna and forest biomes, and attempt to distinguish how each strategic life-history trade-off (carbon storage, bark investment, re-sprouting strategy) contributes towards the maintenance of sharp geographical gradients between fire adapted and typically inflammable closed canopy ecosystems. This study forms part of the planning for a model-inspired fire manipulation experiment at the cerrado-forest boundary in South-Eastern Brazil, and the results will be used to guide future data-collection and analysis strategies.

Development of the BIOME-BGC model for the simulation of managed Moso bamboo forest ecosystems.

Science.gov (United States)

Mao, Fangjie; Li, Pingheng; Zhou, Guomo; Du, Huaqiang; Xu, Xiaojun; Shi, Yongjun; Mo, Lufeng; Zhou, Yufeng; Tu, Guoqing

2016-05-01

Numerical models are the most appropriate instrument for the analysis of the carbon balance of terrestrial ecosystems and their interactions with changing environmental conditions. The process-based model BIOME-BGC is widely used in simulation of carbon balance within vegetation, litter and soil of unmanaged ecosystems. For Moso bamboo forests, however, simulations with BIOME-BGC are inaccurate in terms of the growing season and the carbon allocation, due to the oversimplified representation of phenology. Our aim was to improve the applicability of BIOME-BGC for managed Moso bamboo forest ecosystem by implementing several new modules, including phenology, carbon allocation, and management. Instead of the simple phenology and carbon allocation representations in the original version, a periodic Moso bamboo phenology and carbon allocation module was implemented, which can handle the processes of Moso bamboo shooting and high growth during "on-year" and "off-year". Four management modules (digging bamboo shoots, selective cutting, obtruncation, fertilization) were integrated in order to quantify the functioning of managed ecosystems. The improved model was calibrated and validated using eddy covariance measurement data collected at a managed Moso bamboo forest site (Anji) during 2011-2013 years. As a result of these developments and calibrations, the performance of the model was substantially improved. Regarding the measured and modeled fluxes (gross primary production, total ecosystem respiration, net ecosystem exchange), relative errors were decreased by 42.23%, 103.02% and 18.67%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Update: Dura Mater Graft-Associated Creutzfeldt-Jakob Disease - Japan, 1975-2017.

Science.gov (United States)

Ae, Ryusuke; Hamaguchi, Tsuyoshi; Nakamura, Yosikazu; Yamada, Masahito; Tsukamoto, Tadashi; Mizusawa, Hidehiro; Belay, Ermias D; Schonberger, Lawrence B

2018-03-09

Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative disorder that, according to the most well accepted hypothesis (1), is caused by replicating, transmissible, abnormal forms of a host-encoded prion protein (prions). Most CJD cases occur spontaneously (sporadic CJD) or are inherited (genetic CJD). Iatrogenic CJD can occur after exposure to prion-contaminated instruments or products in medical/surgical settings. Cadaveric dura mater graft-associated CJD (dCJD) accounts for a common form of iatrogenic CJD. This report summarizes the epidemiologic features of 154 cases of dCJD identified in Japan during 1975-2017; these cases account for >60% of dCJD cases reported worldwide (1,2). The unusually high prevalence of dCJD in Japan was first reported in 1997 (3). In 2008, a single brand of graft (Lyodura [B. Braun Melsungen AG, Melsungen, Germany]), frequently used as a patch in neurosurgical procedures, was identified as the probable vehicle of transmission (4). No international recall of the implicated Lyodura occurred, the product had a relatively long shelf life, and the grafts were used frequently in Japanese patients with non-life-threatening conditions (4,5). Since 2008, additional cases have been ascertained, reflecting the identification of previously missed cases and the occurrence of new cases with longer latency periods (interval from exposure to symptom onset) for dCJD (up to 30 years), underscoring the importance of maintaining surveillance for dCJD.

改进Biome-BGC模型模拟哈佛森林地区水、碳通量%Simulation of water and carbon fluxes in Harvard forest area by using improved BiomeBGC model.

Institute of Scientific and Technical Information of China (English)

张廷龙; 孙睿; 胡波; 冯丽超; 张荣华

2011-01-01

Biome-BGC模型通过耦合植被、土壤与大气间的水分与CO2交换过程,实现植被生产力的模拟,但土壤水平衡模块的不够完善,导致在长时间无降水情况下植被生产力模拟存在较大误差.针对这一问题,本文对Biome-BGC模型中土壤水分胁迫气孔导度方程、蒸散计算公式及土壤水分流失过程等3方面进行了改进和调整,利用改进的Biome-BGC模型模拟美国哈佛森林地区蒸散、植被生产力,并与地面通量观测值进行了比较.结果表明,改进后模拟精度有明显的提高,蒸散、植被生态系统生产力(NEE)与观测值间的决定系数分别由0.483和0.658提高到0.617和O.813,蒸散逐年均方根误差平均下降了48.7％,NEE逐年误差平方和平均下降了39.8％.改进后的模型模拟结果更接近观测值.%Using Biome-BGC model can simulate vegetation productivity through the coupling of water and CO2 exchange processes between vegetation, soil and atmosphere, but the soil water balance module is not perfect enough, leading to a large deviation between simulated and observed values under condition of a long time no precipitation. Aiming at this problem, this paper improved and adjusted the equation of stomatal conductance stressed by soil water, the calculation formula of evapotranspiration, and the process of soil water loss in Biome-BGC model. Using this improved model, the evapotranspiration and vegetation productivity in Harvard Forest area were simulated, and compared with field observations. The accuracy of simulated results by the improved model enhanced obviously, with the evapotranspiration R between simulated and observed values increased from 0. 483 to 0. 617, NEE R2 increased from 0. 658 to 0. 813, root mean square error (RMSE) of annual evapotranspiration decreased averagely by 48. 7% , and annual sum squared error ( ASSE) of NEE decreased averagely by 39. 8% , which suggested that the simulated results by using the improved model

Isamaa ja Res Publica Liidu plaan / Juhan Parts

Index Scriptorium Estoniae

Parts, Juhan, 1966-

2008-01-01

Ilmunud ka: Eesti Eest = Za Estoniju : Izdanije objedinenija "Sojuz Otetshestva i Res Publica" 15. mai 2008, lk. 4-5. Eesti majanduse uutest ülesannetest. Kommenteerib: Mart Laar. Vt. samas: IRL-i ettepanekud koalitsioonileppe täienduseks

Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes

Science.gov (United States)

Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A.; Oomen, Roelof J.; du Preez, Chris C.; Ruppert, Jan C.; Ewert, Frank

2014-01-01

Despite our growing knowledge on plants’ functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa’s grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be

Water balance in paired watersheds with eucalyptus and degraded grassland in Pampa biome

Science.gov (United States)

Rangelands of the Pampa biome, which cover regions of Argentina, Uruguay and Brazil (176,496 km2 – 2.07% of Brazilian territory and 63% of Rio Grande do Sul State territory, southern region of Brazil) in South America (total area of 750,000 km2), are being substituted by crops and commercial eucalyp...

A reconstruction of Colombian biomes derived from modern pollen data along an altitude gradient

NARCIS (Netherlands)

Marchant, R.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Helmens, K.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Schreve-Brinkman, E.; Geel, van B.; Reenen, van G.; Hammen, van der T.

2001-01-01

Biomes are reconstructed in Colombia from modern (core-top) pollen data derived from 22 sites along an altitudinal gradient (2000–4100 m) that encompasses the tree line. The `biomization' methodology is described in a stepwise manner that details the reconstruction of vegetation along an altitudinal

A reconstruction of Colombian biomes derived from modern pollen data along an altitude gradient.

NARCIS (Netherlands)

Marchant, R.A.; Behling, H.; Berrio Mogollon, J.C.; Cleef, A.M.; Duivenvoorden, J.F.; van Geel, B.; van der Hammen, T.; Hooghiemstra, H.; Kuhry, P.; Melief, B.M.; van Reenen, G.B.A.; Wille, M.

2001-01-01

Biomes are reconstructed in Colombia from modern (core-top) pollen data derived from twenty-two sites along an altitudinal gradient (2000 to 4100 m) that encompasses the tree line. The 'biomization' methodology is described in a stepwise manner that details the reconstruction of vegetation along an

The Use of Fire Radiative Power to Estimate the Biomass Consumption Coefficient for Temperate Grasslands in the Atlantic Forest Biome

Directory of Open Access Journals (Sweden)

Bibiana Salvador Cabral da Costa

Full Text Available Abstract Every year, many active fire spots are identified in the satellite images of the southern Brazilian grasslands in the Atlantic Forest biome and Pampa biome. Fire Radiative Power (FRP is a technique that uses remotely sensed data to quantify burned biomass. FRP measures the radiant energy released per time unit by burning vegetation. This study aims to use satellite and field data to estimate the biomass consumption rate and the biomass consumption coefficient for the southern Brazilian grasslands. Three fire points were identified in satellite FRP products. These data were combined with field data, collected through literature review, to calculate the biomass consumption coefficient. The type of vegetation is an important variable in the estimation of the biomass consumption coefficient. The biomass consumption rate was estimated to be 2.237 kg s-1 for the southern Brazilian grasslands in Atlantic Forest biome, and the biomass consumption coefficient was estimated to be 0.242 kg MJ-1.

Uso de resíduos de gesso como corretivo em solo salino-sódico

OpenAIRE

Santos, Paulo Medeiros dos; Rolim, Mario Monteiro; Duarte, Anamaria Sousa; Barros, Maria de Fátima Cavalcanti; Silva, Ênio Farias de França e

2014-01-01

Um dos grandes problemas enfrentados pelo setor da construção civil é a destinação final de resíduos, principalmente os resíduos de gesso, que têm sua aptidão para reciclagem restringida. No entanto, tais resíduos possuem altos teores de cálcio, em sua composição, podendo ser uma alternativa ao uso de gesso de jazida, na recuperação de solos salino-sódicos. Esta pesquisa objetivou avaliar a eficiência do uso de resíduos de gesso provenientes da construção civil, em relação ao gesso de jazida,...

Contribution to the discussions on the origin of the cerrado biome: Brazilian savanna

Directory of Open Access Journals (Sweden)

MHO. Pinheiro

Full Text Available Theories that attempt to explain the origin of the cerrado biome are mostly based on the isolated action of three major factors: climate, fire and soil. Another factor that has been mentioned is that of human interference. We hypothesise that the evolutionary origin of this biome resulted from the complex interaction of climate, fire and soil, with climate being the triggering agent of this assumed interaction. Fire, as well as acid and dystrophic soils, would be factors involved in the selection of savanna species throughout climatic events, during the Tertiary and the Quaternary, e.g. Pliocene and Pleistocene. The genesis of the physiognomies that would give rise to cerrado sensu lato, rather than forest formations, could have occurred due to the strong pressure exerted by the reduction in water availability, and the selection of the species adapted to the new conditions imposed by the environment. The characteristics of cerrado sensu lato soil, originated from edaphic impoverishment caused by lixiviation and successive past fires, would remain, even after hydric availability increased following the Pleistocene glaciations.

Ética e pesquisa biomédica em sociedades indígenas no Brasil

Directory of Open Access Journals (Sweden)

Coimbra Jr. Carlos E. A.

1996-01-01

Full Text Available Este trabalho discute questões relativas à ética da investigação biomédica em populações indígenas brasileiras, em particular no que tange à obtenção de consentimento pós-informacional em pesquisas que envolvam a coleta de amostras biológicas. Enfatiza-se que nada há de específico na legislação atual com respeito à pesquisa biomédica nestas populações. A partir de uma perspectiva antropológica, os autores analisam algumas das dificuldades para a obtenção do consentimento "realmente" informado. Chama-se atenção para a importância das discussões sobre ética em pesquisa face a possibilidade de utilização comercial de amostras biológicas, como exemplificado pelo atual debate sobre patenteamento de material genético humano.

Gestão de resíduos sólidos em restaurante escola

Directory of Open Access Journals (Sweden)

Bianca Peruchin

2013-01-01

Full Text Available Um dos maiores problemas ambientais da atualidade é a excessiva geração de resíduos e a sua destinação final ambientalmente adequada. As Instituições de Ensino Superior (IES são importantes fontes geradoras devido à diversidade de atividades de ensino, pesquisa e extensão realizadas no seu âmbito. Os Restaurantes Escola (RE atendem à comunidade acadêmica dos campi universitários, e caracterizam-se por produzir resíduos similares aos domésticos, mas em maior quantidade. Este estudo foi realizado com o objetivo de investigar a composição gravimétrica dos resíduos produzidos em um RE de uma IES localizada no sul do país, bem como conhecer a situação atual do gerenciamento dos resíduos. Os dados foram obtidos através da caracterização dos resíduos do RE durante cinco dias, de entrevista com os gestores responsáveis pelo estabelecimento e da observação direta no local. Averiguou-se a inexistência de um Plano de Gerenciamento dos Resíduos Sólidos no RE, bem como a ausência de práticas efetivas relacionadas ao manejo destes. A segregação dos resíduos é prejudicada devido à falta de lixeiras específicas e a sobrecarga dos funcionários quanto às atividades desempenhadas. Ao longo do período experimental foram caracterizados 547,068 Kg de resíduos, dos quais mais de 80% corresponderam à matéria orgânica. Conclui-se que o montante de resíduo orgânico gerado pode ser destinado à compostagem. Recomenda-se a implantação de uma infraestrutura adequada para o manejo dos resíduos, que pode ser feita através da elaboração e aplicação de um plano de gestão integrada dos resíduos sólidos no RE.Abstract Nowadays, the amount of waste generated and its proper final destination is one of the greatest environmental issues. Higher education institutions are an important source of waste due to the diversity of teaching, researching and extension activities performed in their facilities. The university

Avaliação do gerenciamento dos resíduos de medicamentos e demais resíduos de serviços de saúde na Região Serrana de Santa Catarina

Directory of Open Access Journals (Sweden)

Juliana Aparecida Souza Amarante

2016-10-01

Full Text Available RESUMO A gestão de resíduos dos serviços de saúde (RSS constitui um grande desafio para o poder público, pois, apesar do avanço nos aspectos legislativos, ainda há grandes deficiências, especialmente relacionadas aos resíduos de medicamentos descartados inadequadamente. Este estudo teve como objetivo caracterizar o processo de descarte de drogas e resíduos dos serviços de saúde humana e veterinária em uma cidade de médio porte da Região Serrana de Santa Catarina. Foram realizadas visitas às unidades participantes, selecionadas por critérios de conveniência, contemplando unidades de saúde municipais, pet shops , clínicas veterinárias, hospital de atendimento humano, hospital de atendimento veterinário e empresas coletoras, totalizando 15 unidades participantes. A coleta de dados ocorreu de março a maio de 2014, com aplicação de questionários e roteiro de observação de campo. Os resultados evidenciaram deficiências no gerenciamento dos resíduos de medicamentos, assim como dos demais resíduos, nas etapas de segregação e armazenamento em instituições de atendimento humano e veterinário, com poucas exceções. As maiores dificuldades foram observadas nos estabelecimentos de atendimento veterinário, especialmente quanto à segregação e ao armazenamento dos resíduos contaminados, à falta de cuidado com material perfurocortante e às normas de biossegurança. A inexistência do Plano de Gerenciamento de Resíduos de Serviços de Saúde nas unidades de saúde e no hospital veterinário, assim como a falta de capacitações aos profissionais, a dissimilaridade no descarte de medicamentos entre os estabelecimentos e a falta de fiscalização por parte dos órgãos competentes foram os principais responsáveis pelo atual cenário de descarte inadequado dos resíduos na região.

Energy and climate hand-in-hand: Financing RES-E support with carbon revenues

International Nuclear Information System (INIS)

Verde, Stefano F.; Pazienza, Maria Grazia

2016-01-01

In Italy, the cost of support for renewable electricity (RES-E) is largely recovered through the “A3 surcharge”, which weighs heavily on electricity bills. Using household survey data, we show the A3 surcharge is markedly regressive. Carbon taxation in the non-ETS sector is envisaged as a means to reduce CO_2 emissions cost-effectively and generate revenue to lower the A3 surcharge. A non-ETS carbon tax would be less regressive than the A3 surcharge and its cost would be more evenly distributed across households. We calculate the revenue of a €20/tCO_2 non-ETS carbon tax would have allowed a cut in the A3 surcharge of about 68% in 2011, and 39% in 2012. The impact of the carbon tax plus the reduced A3 surcharge would have been less regressive, but the cost higher for most households. The restrictions imposed in the simulations mean the results are only appropriate to render first-round effects of the reform. Policy relevance: In the vast majority of the EU Member States, the cost of RES-E support is largely paid by electricity consumers, most often through specific surcharges. Rising electricity prices are a common concern given the implications for competitiveness and equity. The Member States facing this issue could conveniently address it through environmental tax reforms consistent with the Climate and Energy Package. Replacing RES-E surcharges with carbon taxes in the non-ETS sector would permit cost-effective reduction of CO_2 emissions while allocating the cost of RES-E support more equitably. The difference in regressivity would stem from the different consumption patterns of home fuels (including electricity) and motor fuels across income distribution. A cross-country comparison of energy household budget shares proves the structural nature of this difference between home fuels and motor fuels. Moreover, the notion that electricity consumers should pay for RES-E support is questioned on the grounds that electricity is a basic necessity good and RES

Large-Area CVD-Grown Sub-2 V ReS2 Transistors and Logic Gates.

Science.gov (United States)

Dathbun, Ajjiporn; Kim, Youngchan; Kim, Seongchan; Yoo, Youngjae; Kang, Moon Sung; Lee, Changgu; Cho, Jeong Ho

2017-05-10

We demonstrated the fabrication of large-area ReS 2 transistors and logic gates composed of a chemical vapor deposition (CVD)-grown multilayer ReS 2 semiconductor channel and graphene electrodes. Single-layer graphene was used as the source/drain and coplanar gate electrodes. An ion gel with an ultrahigh capacitance effectively gated the ReS 2 channel at a low voltage, below 2 V, through a coplanar gate. The contact resistance of the ion gel-gated ReS 2 transistors with graphene electrodes decreased dramatically compared with the SiO 2 -devices prepared with Cr electrodes. The resulting transistors exhibited good device performances, including a maximum electron mobility of 0.9 cm 2 /(V s) and an on/off current ratio exceeding 10 4 . NMOS logic devices, such as NOT, NAND, and NOR gates, were assembled using the resulting transistors as a proof of concept demonstration of the applicability of the devices to complex logic circuits. The large-area synthesis of ReS 2 semiconductors and graphene electrodes and their applications in logic devices open up new opportunities for realizing future flexible electronics based on 2D nanomaterials.

Global soil-climate-biome diagram: linking soil properties to climate and biota

Science.gov (United States)

Zhao, X.; Yang, Y.; Fang, J.

2017-12-01

As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

Variation in decomposition rates in the fynbos biome, South Africa: the role of plant species and plant stoichiometry.

Science.gov (United States)

Bengtsson, Jan; Janion, Charlene; Chown, Steven L; Leinaas, Hans Petter

2011-01-01

Previous studies in the fynbos biome of the Western Cape, South Africa, have suggested that biological decomposition rates in the fynbos vegetation type, on poor soils, may be so low that fire is the main factor contributing to litter breakdown and nutrient release. However, the fynbos biome also comprises vegetation types on more fertile soils, such as the renosterveld. The latter is defined by the shrub Elytropappus rhinocerotis, while the shrub Galenia africana may become dominant in overgrazed areas. We examined decomposition of litter of these two species and the geophyte Watsonia borbonica in patches of renosterveld in an agricultural landscape. In particular, we sought to understand how plant species identity affects litter decomposition rates, especially through variation in litter stoichiometry. Decomposition (organic matter mass loss) varied greatly among the species, and was related to litter N and P content. G. africana, with highest nutrient content, lost 65% of its original mass after 180 days, while E. rhinocerotis had lost ca. 30%, and the very nutrient poor W. borbonica biome. Thus, biological decomposition has likely been underestimated and, along with small-scale variation in ecosystem processes, would repay further study.

Extensiones biométricas para bases de datos objeto- relacionales

OpenAIRE

Miranda, Ernesto; Ruíz, Silvia; Aguirre, Juan José; Herlein, Mauro; Etchart, Graciela; Alvez, Carlos E.

2017-01-01

La autenticación de personas basadas en rasgos biométricos se ha vuelto muy popular en los últimos años como consecuencia de la baja en los costos de los sensores requeridos, su inclusión en dispositivos de consumo masivo y el surgimiento de vulnerabilidades debido al uso de múltiples claves de acceso a diferentes sitios que requieren cierto nivel de seguridad como ser cuentas de correo, sitios de banca electrónica, sistemas corporativos, etc. De todos los rasgos utilizados en biometría, el i...

Soil as a Sustainable Resource for the Bioeconomy - BonaRes

Science.gov (United States)

Wollschläger, Ute; Amelung, Wulf; Brüggemann, Nicolas; Brunotte, Joachim; Gebbers, Robin; Grosch, Rita; Heinrich, Uwe; Helming, Katharina; Kiese, Ralf; Leinweber, Peter; Reinhold-Hurek, Barbara; Veldkamp, Edzo; Vogel, Hans-Jörg; Winkelmann, Traud

2017-04-01

Fertile soils are a fundamental resource for the production of biomass and provision of food and energy. A growing world population and latest climate targets lead to an increasing demand for bio-based products which require preserving and - ideally - improving the long-term productivity of soils as a bio-economic resource. At the same time, other soil functions and ecosystem services need to be maintained: filter for clean water, carbon sequestration, provision and recycling of nutrients, and habitat for biological activity. All these soil functions result from the interaction of a multitude of physical, chemical and biological processes which are insufficiently understood. In addition, we lack understanding about the interplay between the socio-economic system and the soil system and how soil functions benefit human wellbeing, including SDGs. However, a solid and integrated assessment of soil quality requires the consideration of the ensemble of soil functions and its relation to soil management. To make soil management sustainable, we need to establish a scientific knowledge base of complex soil system processes that allows for developing models and tools to quantitatively predict the impact of a multitude of management measures on soil functions. This will finally allow for the provision of options for a site-specific, sustainable soil management. To face this challenge, the German Federal Ministry of Education and Research (BMBF) recently launched the funding program "Soil as a Sustainable Resource for the Bioeconomy - BonaRes". In a joint effort, ten collaborative projects and the coordinating BonaRes Centre are engaged to close existing knowledge gaps for a profound and systemic assessment and understanding of soil functions and their sensitivity to soil management. In BonaRes, the complete process chain of sustainable soil use in the context of a sustainable bio-economy is being addressed: from understanding of soil processes using state-of the art and

[Extensive cranioplasty for sagittal synostosis in young children by preserving multiple cranial bone flaps adhered to the dura mater: experience with 63 cases].

Science.gov (United States)

Bao Nan; Chu Jun; Wang Xue; Yang, Bo; Song, Yunhai; Cai, Jinjing

2016-01-01

This study aimed to evaluate the effort of applying frontal and occipital bones in extensive cranioplasty and preserving multiple cranial bone flaps adhered to the dura mater in the treatment of sagittal synostosis. From April 2008 to June 2013, sixty-three children with sagittal synostosis, aged 5 months to 3 years, were included in the study. The frontal bone flap was removed using an air drill. The occipital and bilateral temporal bone flaps were cut open but not detached from the dura mater or fixed to produce floating bone flaps. The skull bone was cut into palisade-like structures. Brain compression from both sides and the base of the skull was released and the brain expanded bilaterally through the enlarged space. Only a long strip-shaped bone bridge remained in the central parietal bone. Subsequently, the frontal bone flaps and occipital bone flap were pushed towards the midline and fixed with the parietal bone bridge to shorten the anteroposterior diameter of the cranial cavity and allow the brain to expand bilaterally to correct scaphocephaly. The CT images showed that both sides of the parietal bone of artificial sagittal groove gradually merged postoperative 1 year, and skull almost completely normal healing after operation 2 or 3 years, without deformity recurrence within 5 years. Among them all, 61 children's intelligence is normal and 2 children's lagged behind normal level, no further improvement. Patients were followed up 1 - 5 years (an average of 43 months). Skull growth was excellent in all patients, the anteroposterior diameter was shortened by 14.6 mm averagely, the transverse diameter was increased by 12.3 mm averagely, the prominent forehead was corrected, and scaphocephaly improved significantly. There were no complications such as death and skull necrosis. The application of frontal and occipital bones in extensive cranioplasty and preserving multiple cranial bone flaps adhered to the dura mater can be used in the treatment of sagittal

Chemical Vapor Deposition Growth of Degenerate p-Type Mo-Doped ReS2 Films and Their Homojunction.

Science.gov (United States)

Qin, Jing-Kai; Shao, Wen-Zhu; Xu, Cheng-Yan; Li, Yang; Ren, Dan-Dan; Song, Xiao-Guo; Zhen, Liang

2017-05-10

Substitutional doping of transition metal dichalcogenide two-dimensional materials has proven to be effective in tuning their intrinsic properties, such as band gap, transport characteristics, and magnetism. In this study, we realized substitutional doping of monolayer rhenium disulfide (ReS 2 ) with Mo via chemical vapor deposition. Scanning transmission electron microscopy demonstrated that Mo atoms are successfully doped into ReS 2 by substitutionally replacing Re atoms in the lattice. Electrical measurements revealed the degenerate p-type semiconductor behavior of Mo-doped ReS 2 field effect transistors, in agreement with density functional theory calculations. The p-n diode device based on a doped ReS 2 and ReS 2 homojunction exhibited gate-tunable current rectification behaviors, and the maximum rectification ratio could reach up to 150 at V d = -2/+2 V. The successful synthesis of p-type ReS 2 in this study could largely promote its application in novel electronic and optoelectronic devices.

Improved simulation of poorly drained forests using Biome-BGC.

Science.gov (United States)

Bond-Lamberty, Ben; Gower, Stith T; Ahl, Douglas E

2007-05-01

Forested wetlands and peatlands are important in boreal and terrestrial biogeochemical cycling, but most general-purpose forest process models are designed and parameterized for upland systems. We describe changes made to Biome-BGC, an ecophysiological process model, that improve its ability to simulate poorly drained forests. Model changes allowed for: (1) lateral water inflow from a surrounding watershed, and variable surface and subsurface drainage; (2) adverse effects of anoxic soil on decomposition and nutrient mineralization; (3) closure of leaf stomata in flooded soils; and (4) growth of nonvascular plants (i.e., bryophytes). Bryophytes were treated as ectohydric broadleaf evergreen plants with zero stomatal conductance, whose cuticular conductance to CO(2) was dependent on plant water content. Individual model changes were parameterized with published data, and ecosystem-level model performance was assessed by comparing simulated output to field data from the northern BOREAS site in Manitoba, Canada. The simulation of the poorly drained forest model exhibited reduced decomposition and vascular plant growth (-90%) compared with that of the well-drained forest model; the integrated bryophyte photosynthetic response accorded well with published data. Simulated net primary production, biomass and soil carbon accumulation broadly agreed with field measurements, although simulated net primary production was higher than observed data in well-drained stands. Simulated net primary production in the poorly drained forest was most sensitive to oxygen restriction on soil processes, and secondarily to stomatal closure in flooded conditions. The modified Biome-BGC remains unable to simulate true wetlands that are subject to prolonged flooding, because it does not track organic soil formation, water table changes, soil redox potential or anaerobic processes.

BioM2MetDisease: a manually curated database for associations between microRNAs, metabolites, small molecules and metabolic diseases.

Science.gov (United States)

Xu, Yanjun; Yang, Haixiu; Wu, Tan; Dong, Qun; Sun, Zeguo; Shang, Desi; Li, Feng; Xu, Yingqi; Su, Fei; Liu, Siyao; Zhang, Yunpeng; Li, Xia

2017-01-01

BioM2MetDisease is a manually curated database that aims to provide a comprehensive and experimentally supported resource of associations between metabolic diseases and various biomolecules. Recently, metabolic diseases such as diabetes have become one of the leading threats to people’s health. Metabolic disease associated with alterations of multiple types of biomolecules such as miRNAs and metabolites. An integrated and high-quality data source that collection of metabolic disease associated biomolecules is essential for exploring the underlying molecular mechanisms and discovering novel therapeutics. Here, we developed the BioM2MetDisease database, which currently documents 2681 entries of relationships between 1147 biomolecules (miRNAs, metabolites and small molecules/drugs) and 78 metabolic diseases across 14 species. Each entry includes biomolecule category, species, biomolecule name, disease name, dysregulation pattern, experimental technique, a brief description of metabolic disease-biomolecule relationships, the reference, additional annotation information etc. BioM2MetDisease provides a user-friendly interface to explore and retrieve all data conveniently. A submission page was also offered for researchers to submit new associations between biomolecules and metabolic diseases. BioM2MetDisease provides a comprehensive resource for studying biology molecules act in metabolic diseases, and it is helpful for understanding the molecular mechanisms and developing novel therapeutics for metabolic diseases. http://www.bio-bigdata.com/BioM2MetDisease/. © The Author(s) 2017. Published by Oxford University Press.

NEE and GPP dynamic evolution at two biomes in the upper Spanish plateau

Science.gov (United States)

Sánchez, María Luisa; Pardo, Nuria; Pérez, Isidro Alberto; García, Maria de los Angeles

2014-05-01

In order to assess the ability of dominant biomes to act as a CO2 sink, two eddy correlation stations close to each other in central Spain have been concurrently operational since March 2008 until the present. The land use of the first station, AC, is a rapeseed rotating crop consisting of annual rotation of non-irrigated rapeseed, barley, peas, rye, and sunflower, respectively. The land use of the second, CIBA, is a mixture of open shrubs/crops, with open shrubs being markedly dominant. The period of measurements covered variable general meteorological conditions. 2009 and 2012 were dominated by drought, whereas 2010 was the rainiest year. Annual rainfall during 2008 and 2009 was close to the historical averaged annual means. This paper presents the dynamic evolution of NEE-8d and GPP-8d observed at the AC station over five years and compares the results with those concurrently observed at the CIBA station. GGP 8-d estimates at both stations were determined using a Light Use Efficiency Model, LUE. Input data for the LUE model were the FPAR 8-d products supplied by MODIS, PAR in situ measurements, and a scalar f, varying between 0 and 1, to take account of the reduction in maximum PAR conversion efficiency, ɛ0, under limiting environmental conditions. f values were assumed to be dependent on air temperature and evaporative fraction, EF, which was considered a proxy of soil moisture. ɛ0, a key parameter, which depends on land use types, was derived through the results of a linear regression fit between the GPP 8-d eddy covariance composites observed and the LUE concurrent 8-d model estimates. Over the five-year study period, both biomes behaved as CO2 sinks. However, the ratio of the NEE-8d total accumulated at AC and CIBA, respectively, was close to a factor two, revealing the effectiveness of the studied crops as CO2 sinks. On an annual basis, accumulated NEE-8d exhibited major variability in both biomes. At CIBA, the results were largely dominated by the

Les objectifs et les critères de sélection. Les aptitudes bouchères : croissance, efficacité alimentaire et qualité de la carcasse

OpenAIRE

SELLIER, Pierre; BOUIX, J.; Renand, Gilles; MOLENAT, M.

1992-01-01

Les programmes de sélection sur les aptitudes bouchères ont un double objectif : l’abaissement du coût de production et l’amélioration de la qualité du produit. Cet article rappelle un certain nombre de données de base sur les aptitudes bouchères : courbe de croissance, évolution de la composition chimique et tissulaire chez l’animal en croissance (notion d’allométrie), énergétique de la croissance (relation entre efficacité alimentaire et croissance musculaire), développement des tissus musc...

Simulating carbon and water fluxes at Arctic and boreal ecosystems in Alaska by optimizing the modified BIOME-BGC with eddy covariance data

Science.gov (United States)

Ueyama, M.; Kondo, M.; Ichii, K.; Iwata, H.; Euskirchen, E. S.; Zona, D.; Rocha, A. V.; Harazono, Y.; Nakai, T.; Oechel, W. C.

2013-12-01

To better predict carbon and water cycles in Arctic ecosystems, we modified a process-based ecosystem model, BIOME-BGC, by introducing new processes: change in active layer depth on permafrost and phenology of tundra vegetation. The modified BIOME-BGC was optimized using an optimization method. The model was constrained using gross primary productivity (GPP) and net ecosystem exchange (NEE) at 23 eddy covariance sites in Alaska, and vegetation/soil carbon from a literature survey. The model was used to simulate regional carbon and water fluxes of Alaska from 1900 to 2011. Simulated regional fluxes were validated with upscaled GPP, ecosystem respiration (RE), and NEE based on two methods: (1) a machine learning technique and (2) a top-down model. Our initial simulation suggests that the original BIOME-BGC with default ecophysiological parameters substantially underestimated GPP and RE for tundra and overestimated those fluxes for boreal forests. We will discuss how optimization using the eddy covariance data impacts the historical simulation by comparing the new version of the model with simulated results from the original BIOME-BGC with default ecophysiological parameters. This suggests that the incorporation of the active layer depth and plant phenology processes is important to include when simulating carbon and water fluxes in Arctic ecosystems.

Comment rendre les villes plus sûres | CRDI - Centre de recherches ...

International Development Research Centre (IDRC) Digital Library (Canada)

29 oct. 2015 ... À mi-chemin d'un programme quinquennal de recherche, les experts qui travaillent à l'initiative Villes sûres et inclusives font la lumière sur ce qui fonctionne – et ne fonctionne pas – pour rendre les villes plus sûres. Le présent compte rendu présente certains enseignements tirés de leur travail, ainsi que ...

Loading Intensity Prediction by Velocity and the OMNI-RES 0-10 Scale in Bench Press.

Science.gov (United States)

Naclerio, Fernando; Larumbe-Zabala, Eneko

2017-02-01

Naclerio, F and Larumbe-Zabala, E. Loading intensity prediction by velocity and the OMNI-RES 0-10 scale in bench press. J Strength Cond Res 32(1): 323-329, 2017-This study examined the possibility of using movement velocity and the perceived exertion as indicators of relative load in the bench press (BP) exercise. A total of 308 young, healthy, resistance trained athletes (242 men and 66 women) performed a progressive strength test up to the one repetition maximum for the individual determination of the full load-velocity and load-exertion relationships. Longitudinal regression models were used to predict the relative load from the average velocity (AV) and the OMNI-Resistance Exercise Scales (OMNI-RES 0-10 scale), considering sets as the time-related variable. Load associated with the AV and the OMNI-RES 0-10 scale value expressed after performing a set of 1-3 repetitions were used to construct 2 adjusted predictive equations: Relative load = 107.75 - 62.97 × average velocity; and Relative load = 29.03 + 7.26 × OMNI-RES 0-10 scale value. The 2 models were capable of estimating the relative load with an accuracy of 84 and 93%, respectively. These findings confirm the ability of the 2 calculated regression models, using load-velocity and load-exertion from the OMNI-RES 0-10 scale, to accurately predict strength performance in BP.

Comentário sobre as Res Gestae Divi Avgvsti

Directory of Open Access Journals (Sweden)

Maria Luiza Corassin

2004-12-01

Full Text Available This article studies an epigraphic source, Augustus's Res gestae, which provides elements that elucidate the construction of the imperial power system and the relationship between ruler and ruled.

La rehabilitación de un ícono de la modernidad la Iglesia Mater Misericordiae = The rehabilitation of an icon of modernity the Church Mater Misericordiae

Directory of Open Access Journals (Sweden)

María Belén Gómez

2017-12-01

Full Text Available La iglesia Mater Misericordiae es un edificio sacro levantado en Baranzate (Milán a finales de la década de los años 50.Supone la culminación de una serie de experiencias que pretendían la renovación de la liturgia y, con ello, la renovación de laarquitectura. Su construcción, enmarcada dentro de un plan más amplio acometido por el Arzobispado de Milán, supuso un gran avance en varios campos relacionados, principalmente, con la modernidad de la arquitectura sacra, la construcción y las nuevas tecnologías. Incorpora el uso no solamente del hormigón, material poco utilizado hasta ese momento en construcciones sacras, sino que, además, introduce un sistema de prefabricación y postesado “In situ” para la ejecución de la estructura que muestra el interés de los técnicos de la época por hallar nuevos medios de sistematización de la construcción. El sistema constructivo de cerramiento utilizado permite delimitar el espacio litúrgico mediante una piel translúcida que rodea el espacio, permitiendo la entrada de luz natural durante el día y la iluminación del entorno durante la noche. La presente investigación trata sobre las diferentes soluciones que se han empleado en la resolución de las fachadas de cerramiento, haciendo especial hincapié en la solución utilizada en la última rehabilitación a la que ha sido sometida. En este caso se han tratado de incorporar las tecnologías modernas más avanzadas para la resolución de los problemas que esta presentaba pero respetando al máximo la idea del proyecto original. Abstract The church Mater Misericordiae is a sacred building raised in Baranzate (Milan at the end of the decade of the 50s. It supposes the culmination of a series of experiences that were claiming the renovation of the liturgy and, with it, the renovation of the architecture. His construction, framed within a broader plan undertaken by the Archbishopric of Milan, supposed a great advance in several fields

The Biome Project: Developing a Legitimate Parallel Curriculum for Physical Education and Life Sciences

Science.gov (United States)

Hastie, Peter Andrew

2013-01-01

The purpose of this article is to describe the outcomes of a parallel curriculum project between life sciences and physical education. Throughout a 6-week period, students in grades two through five became members of teams that represented different animal species and biomes, and concurrently participated in a season of gymnastics skills and…

Sectional removable partial denture design for the treatment of ...

African Journals Online (AJOL)

Sectional removable partial denture design for the treatment of partial mandibulectomy patient: a case report. ... mandibulectomy with no surgical reconstruction. The case was challenging and the prosthesis was well tolerated during a 6 months follow-up review. (Afr. J. Biomed. Res. 10: 197 - 201). Keywords: Removable ...

Modèle de régression optimale des traits de conformation et de la ...

African Journals Online (AJOL)

SARAH

31 mai 2017 ... control.It was found that daily milk production was positively ... éleveurs, ni à leurs méthodes de gestion des ... performances laitières par l'analyse des corrélations, ... Les méthodes de mesure biométrique : En station,.

Effects of methanolic root extract of ledebouria ovaltifolia ...

African Journals Online (AJOL)

of the extract was non specific on muscarinic, adreneceptors nor depolarised membrane site. The effect of the extract was more marked on potassium (K+) than receptor mediated contractions. (Afr. J. Biomed. Res. 11: 232 - 327). Key Words; ledebouria Ovaltifolia, Extract, methanolic, smooth muscle contractions, rodents ...

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

Science.gov (United States)

Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

2015-01-01

The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa

Science.gov (United States)

Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

2015-01-01

The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

Directory of Open Access Journals (Sweden)

Julian Martin Corbelli

Full Text Available The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD, functional (FBD and phylogenetic (PBD facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants from two contrasting biomes (subtropical forest and grassland and land uses (tree plantations and cropfields in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland, and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

Understanding and Controlling Living/Inorganic Interfaces to Enable Reconfigurable Switchable Materials

Science.gov (United States)

2018-03-01

Mater Res. 2015;4:297–310. Invited. Dong H, Sarkes DA, Rice JJ , Hurley MM, Fu A, Stratis-Cullum D. Functionalization of living bacterial cells with...presentation. Dong H, Sarkes DA, Rice JJ , Hurley MM, Fu A, Stratis-Cullum D. Living composites: Viable bacteria-nanoparticle hybrids mediated through...surface- displayed peptides. Langmuir. Forthcoming 2017. Dong H, Sarkes DA, Rice JJ , Hurley MM, Fu A, Stratis-Cullum DN. Living bacteria/nanoparticle

Synthesis and photoluminescence study of narrow-band UVB ...

Indian Academy of Sciences (India)

[7] Guo C, Ding X, Seo H J, Ren Z and Bai J 2011 J. Alloys. Compd. 509 4871. [8] Zhang X, Lang H and Seo H 2011 J. Fluoresc. 21 1111. [9] Zhang Z W 2013 Ceram. Int. 39 1723. [10] Yu H 2012 J. Lumin. 132 2553. [11] Wang Q 2012 J. Lumin. 132 434. [12] Palan C, Bajaj N and Omanwar S 2016 Mater. Res. Bull. 76 216.

Transforming a school: A case study of a Catholic school principal in Indonesia

OpenAIRE

Siok Fei Oei

2015-01-01

Transforming a struggling private Catholic Vocation al School into a well-improved school requires a lot of hard work. Improving a school allowed for no sho rt-cut to assure students’ high achievement. An outstanding school was the res ult of much hard work. The current case study shall focus on the journey of Mater Amabilis School for Training Home Economics Teachers (MA SGKP). More specifically, the paper sh all ...

Modeling the Ecosystem Services Provided by Trees in Urban Ecosystems: Using Biome-BGC to Improve i-Tree Eco

Science.gov (United States)

Brown, Molly E.; McGroddy, Megan; Spence, Caitlin; Flake, Leah; Sarfraz, Amna; Nowak, David J.; Milesi, Cristina

2012-01-01

As the world becomes increasingly urban, the need to quantify the effect of trees in urban environments on energy usage, air pollution, local climate and nutrient run-off has increased. By identifying, quantifying and valuing the ecological activity that provides services in urban areas, stronger policies and improved quality of life for urban residents can be obtained. Here we focus on two radically different models that can be used to characterize urban forests. The i-Tree Eco model (formerly UFORE model) quantifies ecosystem services (e.g., air pollution removal, carbon storage) and values derived from urban trees based on field measurements of trees and local ancillary data sets. Biome-BGC (Biome BioGeoChemistry) is used to simulate the fluxes and storage of carbon, water, and nitrogen in natural environments. This paper compares i-Tree Eco's methods to those of Biome-BGC, which estimates the fluxes and storage of energy, carbon, water and nitrogen for vegetation and soil components of the ecosystem. We describe the two models and their differences in the way they calculate similar properties, with a focus on carbon and nitrogen. Finally, we discuss the implications of further integration of these two communities for land managers such as those in Maryland.

Assessment of water pollution in the Brazilian Pampa biome by means of stress biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii (Anura: Hylidae).

Science.gov (United States)

Santos, T G; Melo, R; Costa-Silva, D G; Nunes, Mem; Rodrigues, N R; Franco, J L

2015-01-01

The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Studies with a focus on the assessment of impacts caused by human activities in this biome are scarce. In the present study, we measured stress-related biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii, an endemic species to the Pampa biome, and tested its suitability as a bioindicator for the assessment of potential aquatic contamination in selected ponds (S1 and S2) nearby agricultural areas in comparison to a reference site. A significant decrease in acetylcholinesterase activity was observed in S2 when compared to S1 and reference. The levels of total-hydroperoxides were increased in S2 site. In parallel, increased activity of the antioxidant enzymes catalase, superoxide dismutase and glutathione S-transferase were observed in S2 when compared to S1 and reference. Further studies are necessary in order to correlate the changes observed here with different chemical stressors in water, as well as to elucidate mechanisms of toxicity induced by pesticides in amphibian species endemic to the Pampa biome. Nevertheless, our study validates Phyllomedusa iheringii as a valuable bioindicator in environmental studies.

Comparative patterns of plant invasions in the Mediterranean biome.

Science.gov (United States)

Arianoutsou, Margarita; Delipetrou, Pinelopi; Vilà, Montserrat; Dimitrakopoulos, Panayiotis G; Celesti-Grapow, Laura; Wardell-Johnson, Grant; Henderson, Lesley; Fuentes, Nicol; Ugarte-Mendes, Eduardo; Rundel, Philip W

2013-01-01

The objective of this work was to compare and contrast the patterns of alien plant invasions in the world's five mediterranean-climate regions (MCRs). We expected landscape age and disturbance history to have bearing on levels of invasion. We assembled a database on naturalized alien plant taxa occurring in natural and semi-natural terrestrial habitats of all five regions (specifically Spain, Italy, Greece and Cyprus from the Mediterranean Basin, California, central Chile, the Cape Region of South Africa and Southwestern - SW Australia). We used multivariate (hierarchical clustering and NMDS ordination) trait and habitat analysis to compare characteristics of regions, taxa and habitats across the mediterranean biome. Our database included 1627 naturalized species with an overall low taxonomic similarity among the five MCRs. Herbaceous perennials were the most frequent taxa, with SW Australia exhibiting both the highest numbers of naturalized species and the highest taxonomic similarity (homogenization) among habitats, and the Mediterranean Basin the lowest. Low stress and highly disturbed habitats had the highest frequency of invasion and homogenization in all regions, and high natural stress habitats the lowest, while taxonomic similarity was higher among different habitats in each region than among regions. Our analysis is the first to describe patterns of species characteristics and habitat vulnerability for a single biome. We have shown that a broad niche (i.e. more than one habitat) is typical of naturalized plant species, regardless of their geographical area of origin, leading to potential for high homogenization within each region. Habitats of the Mediterranean Basin are apparently the most resistant to plant invasion, possibly because their landscapes are generally of relatively recent origin, but with a more gradual exposure to human intervention over a longer period.

Autenticación mediante parámetros biométricos

OpenAIRE

Pastor Navarro, Ricard

2017-01-01

En les pàgines següents s’explicarà el procés seguit per la realització d’aquest treball de final de grau, en el que es pretén substituir, en un programa de gestió de contrasenyes, la contrasenya mestre per paràmetres biomètrics, concretament el reconeixement facial. Per a complir amb aquest objectiu s’utilitzaran alguns algoritmes de visió per computador extrets de les llibreries de OpenCV. El sistema final agafarà imatges de l’usuari i fent la comprovació del usuari decidint si ha de donar ...

Evaluation of corrosion resistance of implant-use Ti-Zr binary alloys with a range of compositions.

Science.gov (United States)

Akimoto, Teisuke; Ueno, Takeshi; Tsutsumi, Yusuke; Doi, Hisashi; Hanawa, Takao; Wakabayashi, Noriyuki

2018-01-01

Although titanium-zirconium (Ti-Zr) alloy has been adopted for clinical applications, the ideal proportion of Zr in the alloy has not been identified. In this study, we investigated the biocompatibility of Ti-Zr alloy by evaluating its corrosion resistance to better understand whether there is an optimal range or value of Zr proportion in the alloy. We prepared pure Ti, Ti-30Zr, Ti-50Zr, Ti-70Zr, and pure Zr (mol% of Zr) samples and subjected them to anodic polarization and immersion tests in a lactic acid + sodium chloride (NaCl) solution and artificial saliva. We observed pitting corrosion in the Ti-70Zr and Zr after exposure to both solutions. After the immersion test, we found that pure Ti exhibited the greatest degree of dissolution in the lactic acid + NaCl solution, with the addition of Zr dramatically reducing Ti ion dissolution, with the reduction ultimately exceeding 90% in the case of the Ti-30Zr. Hence, although the localized corrosion resistance under severe conditions was compromised when the Zr content was more than 70%, metal ion release reduced owing to Zr addition and the corresponding formation of a stable passive layer. The results suggest that Ti-30Zr or a Zr proportion of less than 50% would offer an ideal level of corrosion resistance for clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 73-79, 2018. © 2016 Wiley Periodicals, Inc.

Magnetic iron oxide nanoparticles (MIONs) cross-linked natural polymer-based hybrid gel beads: Controlled nano anti-TB drug delivery application.

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Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Vijayakumar, Vijayaparthasarathi; Dhaveethu Raja, Jeyaraj; Annaraj, Jamespandi; Sakthipandi, Kathiresan; Rajesh, Jegathalaprathaban

2018-04-01

The nanosized rifampicin (RIF) has been prepared to increase the solubility in aqueous solution, which leads to remarkable enhancement of its bioavailability and their convenient delivery system studied by newly produced nontoxic, biodegradable magnetic iron oxide nanoparticles (MIONs) cross-linked polyethylene glycol hybrid chitosan (mCS-PEG) gel beads. The functionalization of both nano RIF and mCS-PEG gel beads were studied using various spectroscopic and microscopic techniques. The size of prepared nano RIF was found to be 70.20 ± 3.50 nm. The mechanical stability and swelling ratio of the magnetic gel beads increased by the addition of PEG with a maximum swelling ratio of 38.67 ± 0.29 g/g. Interestingly, this magnetic gel bead has dual responsive assets in the nano drug delivery application (pH and the magnetic field). As we expected, magnetic gel beads show higher nano drug releasing efficacy at acidic medium (pH = 5.0) with maximum efficiency of 71.00 ± 0.87%. This efficacy may also be tuned by altering the external magnetic field and the weight percentage (wt%) of PEG. These results suggest that such a dual responsive magnetic gel beads can be used as a potential system in the nano drug delivery applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1039-1050, 2018. © 2017 Wiley Periodicals, Inc.

Influence of zeolite shape and particle size on their capacity to adsorb uremic toxin as powders and as fillers in membranes.

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Lu, Limin; Chen, Chen; Samarasekera, Champika; Yeow, John T W

2017-08-01

Membranes with zeolites are promising for performing blood dialysis because zeolites can eliminate uremic toxins through molecular sieving. Although the size and the shape of zeolite particles can potentially influence the performance of the membranes with respect of creatinine uptake level, it is not clear what sizes and shapes lead to better performance. In this paper, we carry out experiments to answer this question. Spherical microparticle 840, spherical nanoparticle P-87 and rod-like nanoparticle P-371 zeolites were chosen to be used in all the experiments. Their creatinine uptake levels were first measured as powders in creatinine solutions with different concentrations, volumes and adsorption times. Then, nanofibrous membranes with zeolites were electrospun and their ability to adsorb creatinine was measured and compared against their respective powders' creatinine uptake level. The experiment shows that the zeolites have similar creatinine uptake ability as powders. However, they have significantly different creatinine uptake ability after being incorporated inside the membranes. Spherical microparticle 840 in the membrane presented the best creatinine uptake ability, at 8957 µg g -1 , which was half of its powders'. On the other hand, P-87 presented largely decreased, while P-371 presented even lower creatinine uptake ability in membranes when compared to respective powders'. The results shows that microparticle and sphere shaped particles perform better inside the membranes. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1594-1601, 2017. © 2016 Wiley Periodicals, Inc.

The influence of buffer system and biological fluids on the degradation of magnesium.

Science.gov (United States)

Törne, Karin; Örnberg, Andreas; Weissenrieder, Jonas

2017-08-01

The influence of frequently used buffer system 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) compared to CO 2 /HCO3- on the corrosion of magnesium is investigated. Samples were immersed in simulated body fluid (m-SBF) while monitored by electrochemical impedance spectroscopy (EIS) for up to 30 days. In CO 2 /HCO3- the initial corrosion rate was 0.11 mm yr -1 . An inner protective layer of magnesium oxide was formed within the first 30 min exposure and subsequently covered by an outer layer of apatite within 24 h . The corrosion mechanism thereafter is best described as passive pitting with a porosity of ∼10%. Using HEPES as buffer agent increased the corrosion rate to 3.37 mm yr -1 . Cross sectional microscopy show a porous outer corrosion layer allowing rapid diffusion of aggressive ions through the film. Here the EIS results are best described by an active pitting model with an inner layer 5 to 10 times less protective compared to the inner layer formed without HEPES. Further the suitability of human whole blood and plasma as in vitro models for Mg degradation was evaluated. Mg corrosion caused coagulation after 24 h in both biological fluids. The corrosion during the first 24 h is similar to the corrosion in m-SBF with HEPES. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1490-1502, 2017. © 2016 Wiley Periodicals, Inc.

Preparation, characterization and in vitro response of bioactive coatings on polyether ether ketone.

Science.gov (United States)

Durham, John W; Allen, Matthew J; Rabiei, Afsaneh

2017-04-01

Polyether ether ketone (PEEK) is a highly heat-resistant thermoplastic with excellent strength and elastic modulus similar to human bone, making it an attractive material for orthopedic implants. However, the hydrophobic surface of PEEK implants induces fibrous encapsulation which is unfavorable for stable implant anchorage. In this study, PEEK was coated via ion-beam-assisted deposition (IBAD) using a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to improve osseointegration. Microstructural analysis of the coatings showed a dense, uniform columnar grain structure in the YSZ layer and no delamination from the substrate. The HA layer was found to be amorphous and free of porosities in its as-deposited state. Subsequent heat treatment via microwave energy followed by autoclaving crystallized the HA layer, confirmed by SEM and XRD analysis. An in vitro study using MC3T3 preosteoblast cells showed improved bioactivity in heat-treated sample groups. Cell proliferation, differentiation, and mineralization were analyzed by MTT assay and DNA content, osteocalcin expression, and Alizarin Red S (AR-S) content, respectively. Initial cell growth was increased, and osteogenic maturation and mineralization were accelerated most on coatings that underwent a combined microwave and autoclave heat treatment process as compared to uncoated PEEK and amorphous HA surfaces. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 560-567, 2017. © 2015 Wiley Periodicals, Inc.

Effect of osteoporosis on fixation of osseointegrated implants in rats.

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Li, Yunfeng; He, Sheng; Hua, Yunwei; Hu, Jing

2017-11-01

The effect of osteoporosis on implant osseointegration has been widely investigated, whereas osteoporosis may also newly occur in patient with previously osseointegrated implant. This study was designed to investigate the effect of osteoporosis on implant fixation in rats after successful osseointegration had been obtained. Seventy female Sprague-Dawley rats were included, and each animal received two titanium implants in the distal metaphysis of femur bilaterally. Eight weeks later, ten rats were sacrificed to confirm the establishment of implant osseointegration. All left rats were randomly subjected to bilateral ovariectomy (OVX) or sham operation. Three, six, and twelve weeks later, implant osseointegration, peri-implant bone tissue, and biomechanical properties of implant were analyzed. Right femurs with implants were used for micro-CT and histological analysis, and left femurs with implants were used for biomechanical test. Micro-CT, histology, and biomechanical test confirmed the destructive effect of OVX on previously osseointegrated implant in rats; when compared to sham-operated rats, peri-implant bone volume, trabecular architecture, bone-to-implant contact ratio, as well as biomechanical parameters decreased progressively within 12 weeks. Results also indicated that the effect of OVX on undisturbed bone (proximal tibiae) was much stronger than that on peri-implant bone. Osteoporosis produced a progressive negative effect on previously osseointegrated implant in distal femora of rats during 12 weeks. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2426-2432, 2017. © 2016 Wiley Periodicals, Inc.

Effect of cartilaginous matrix components on the chondrogenesis and hypertrophy of mesenchymal stem cells in hyaluronic acid hydrogels.

Science.gov (United States)

Zhu, Meiling; Feng, Qian; Sun, Yuxin; Li, Gang; Bian, Liming

2017-11-01

The microenvironment of the extracellular matrix (ECM) plays a key role in directing the viability and subsequent differentiation of the encapsulated stem cells by the specific integration between the hydrated biomolecules and cell surface receptors. Herein, we developed a hydrogel platform based on hyaluronic acid (HA) that presents cartilage ECM molecules as a form of developmental cues. The hybrid hydrogels were generated by coupling photo-cross-linkable methacrylated HA (MeHA) with selected cartilaginous ECM molecules including chondroitin sulfate (CS) and type I collagen (Col I), and we studied the decoupled function of these cues in regulating the initial chondrogenesis, subsequent hypertrophy, and tissue mineralization by hMSCs. The results indicate upregulated mRNA expression of the chondrogenesis markers in the HA hydrogels that contain Col I or CS, and decreased expression of the hypertrophic markers compared with the control MeHA group. The quantification results also show that glycosaminoglycans accumulation increases in the hybrid hydrogels containing cartilaginous ECM molecules, both in vitro and in vivo. We hypothesize that these additional ECM components in the HA hydrogels further regulate the hMSCs chondrogenesis and hypertrophy by coordination. The understanding obtained in this study may guide biomaterial scaffold design, thereby facilitating manipulation of the differentiation and mineralization of induced hMSCs for application in the repair of different musculoskeletal defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2292-2300, 2017. © 2016 Wiley Periodicals, Inc.

In vitro biological evaluation of beta-TCP/HDPE--A novel orthopedic composite: a survey using human osteoblast and fibroblast bone cells.

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Homaeigohar, S Sh; Shokrgozar, M A; Khavandi, A; Sadi, A Yari

2008-02-01

Beta-tricalcium phosphate reinforced high density polyethylene (beta-TCP/HDPE) was prepared to simulate bone composition and to study its capacity to act as bone tissue. This material was produced by replacing the mineral component and collagen soft tissue of the bone with beta-TCP and HDPE, respectively. The biocompatibility of the composite samples with different volume fractions of TCP (20, 30 and 40 vol %) was examined in vitro using two osteoblast cell lines G-292 and Saos-2, and also a type of fibroblast cell isolated from bone tissue, namely human bone fibroblast (HBF) by proliferation, and cell adhesion assays. Cell-material interaction with the surface of the composite samples was examined by scanning electron microscopy (SEM). The effect of beta-TCP/HDPE on the behavior of osteoblast and fibroblast cells was compared with those of composite and negative control samples; polyethylene (PE) and tissue culture polystyrene (TPS), respectively. In general, the results showed that the composite samples containing beta-TCP as reinforcement supported a higher rate of proliferation by various bone cells after 3, 7, and 14 days of incubation compared to the composite control sample. Furthermore, more osteoblast cells were attached to the surface of the composite samples when compared to the composite control samples after the above incubation periods (p HDPE composites are biocompatible, nontoxic, and act to stimulate proliferation and adhesion of the cells, whether osteoblast or fibroblast. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

Crosslinked basement membrane-based coatings enhance glucose sensor function and continuous glucose monitoring in vivo.

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Klueh, Ulrike; Ludzinska, Izabela; Czajkowski, Caroline; Qiao, Yi; Kreutzer, Donald L

2018-01-01

Overcoming sensor-induced tissue reactions is an essential element of achieving successful continuous glucose monitoring (CGM) in the management of diabetes, particularly when used in closed loop technology. Recently, we demonstrated that basement membrane (BM)-based glucose sensor coatings significantly reduced tissue reactions at sites of device implantation. However, the biocompatible BM-based biohydrogel sensor coating rapidly degraded over a less than a 3-week period, which effectively eliminated the protective sensor coating. In an effort to increase the stability and effectiveness of the BM coating, we evaluated the impact of crosslinking BM utilizing glutaraldehyde as a crosslinking agent, designated as X-Cultrex. Sensor performance (nonrecalibrated) was evaluated for the impact of these X-Cultrex coatings in vitro and in vivo. Sensor performance was assessed over a 28-day time period in a murine CGM model and expressed as mean absolute relative difference (MARD) values. Tissue reactivity of Cultrex-coated, X-Cultrex-coated, and uncoated glucose sensors was evaluated over a 28-day time period in vivo using standard histological techniques. These studies demonstrated that X-Cultrex-based sensor coatings had no effect on glucose sensor function in vitro. In vivo, glucose sensor performance was significantly enhanced following X-Cultrex coating throughout the 28-day study. Histological evaluations of X-Cultrex-treated sensors demonstrated significantly less tissue reactivity when compared to uncoated sensors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 7-16, 2018. © 2017 Wiley Periodicals, Inc.

In vitro biocorrosion of Ti-6Al-4V implant alloy by a mouse macrophage cell line.

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Lin, Hsin-Yi; Bumgardner, Joel D

2004-03-15

Corrosion of implant alloys releasing metal ions has the potential to cause adverse tissue reactions and implant failure. We hypothesized that macrophage cells and their released reactive chemical species (RCS) affect the alloy's corrosion properties. A custom cell culture corrosion box was used to evaluate how cell culture medium, macrophage cells and RCS altered the Ti-6Al-4V corrosion behaviors in 72 h and how corrosion products affected the cells. There was no difference in the charge transfer in the presence (75.2 +/- 17.7 mC) and absence (62.3 +/- 18.8 mC) of cells. The alloy had the lowest charge transfer (28.2 +/- 4.1 mC) and metal ion release (Ti < 10 ppb, V < 2 ppb) with activated cells (releasing RCS) compared with the other two conditions. This was attributed to an enhancement of the surface oxides by RCS. Metal ion release was very low (Ti < 20 ppb, V < 10 ppb) with nonactivated cells and did not change cell morphology, viability, and NO and ATP release compared with controls. However, IL-1beta released from the activated cells and the proliferation of nonactivated cells were greater on the alloy than the controls. In summary, macrophage cells and RCS reduced the corrosion of Ti-6Al-4V alloys as hypothesized. These data are important in understanding host tissue-material interactions. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 717-724, 2004

Fiber/collagen composites for ligament tissue engineering: influence of elastic moduli of sparse aligned fibers on mesenchymal stem cells.

Science.gov (United States)

Thayer, Patrick S; Verbridge, Scott S; Dahlgren, Linda A; Kakar, Sanjeev; Guelcher, Scott A; Goldstein, Aaron S

2016-08-01

Electrospun microfibers are attractive for the engineering of oriented tissues because they present instructive topographic and mechanical cues to cells. However, high-density microfiber networks are too cell-impermeable for most tissue applications. Alternatively, the distribution of sparse microfibers within a three-dimensional hydrogel could present instructive cues to guide cell organization while not inhibiting cell behavior. In this study, thin (∼5 fibers thick) layers of aligned microfibers (0.7 μm) were embedded within collagen hydrogels containing mesenchymal stem cells (MSCs), cultured for up to 14 days, and assayed for expression of ligament markers and imaged for cell organization. These microfibers were generated through the electrospinning of polycaprolactone (PCL), poly(ester-urethane) (PEUR), or a 75/25 PEUR/PCL blend to produce microfiber networks with elastic moduli of 31, 15, and 5.6 MPa, respectively. MSCs in composites containing 5.6 MPa fibers exhibited increased expression of the ligament marker scleraxis and the contractile phenotype marker α-smooth muscle actin versus the stiffer fiber composites. Additionally, cells within the 5.6 MPa microfiber composites were more oriented compared to cells within the 15 and 31 MPa microfiber composites. Together, these data indicate that the mechanical properties of microfiber/collagen composites can be tuned for the engineering of ligament and other target tissues. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1894-1901, 2016. © 2016 Wiley Periodicals, Inc.

Surface sulfonamide modification of poly(N-isopropylacrylamide)-based block copolymer micelles to alter pH and temperature responsive properties for controlled intracellular uptake.

Science.gov (United States)

Cyphert, Erika L; von Recum, Horst A; Yamato, Masayuki; Nakayama, Masamichi

2018-06-01

Two different surface sulfonamide-functionalized poly(N-isopropylacrylamide)-based polymeric micelles were designed as pH-/temperature-responsive vehicles. Both sulfadimethoxine- and sulfamethazine-surface functionalized micelles were characterized to determine physicochemical properties, hydrodynamic diameters, zeta potentials, temperature-dependent size changes, and lower critical solution temperatures (LCST) in both pH 7.4 and 6.8 solutions (simulating both physiological and mild low pH conditions), and tested in the incorporation of a proof-of-concept hydrophobic antiproliferative drug, paclitaxel. Cellular uptake studies were conducted using bovine carotid endothelial cells and fluorescently labeled micelles to evaluate if there was enhanced cellular uptake of the micelles in a low pH environment. Both variations of micelles showed enhanced intracellular uptake under mildly acidic (pH 6.8) conditions at temperatures slightly above their LCST and minimal uptake at physiological (pH 7.4) conditions. Due to the less negative zeta potential of the sulfamethazine-surface micelles compared to sulfadimethoxine-surface micelles, and the proximity of their LCST to physiological temperature (37°C), the sulfamethazine variation was deemed more amenable for clinically relevant temperature and pH-stimulated applications. Nevertheless, we believe both polymeric micelle variations have the capacity to be implemented as an intracellular drug or gene delivery system in response to mildly acidic conditions. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1552-1560, 2018. © 2018 Wiley Periodicals, Inc.

Effect of etching with distinct hydrofluoric acid concentrations on the flexural strength of a lithium disilicate-based glass ceramic.

Science.gov (United States)

Prochnow, Catina; Venturini, Andressa B; Grasel, Rafaella; Bottino, Marco C; Valandro, Luiz Felipe

2017-05-01

This study examined the effects of distinct hydrofluoric acid concentrations on the mechanical behavior of a lithium disilicate-based glass ceramic. Bar-shaped specimens were produced from ceramic blocks (e.max CAD, Ivoclar Vivadent). The specimens were polished, chamfered, and sonically cleaned in distilled water. The specimens were randomly divided into five groups (n = 23). The HF1, HF3, HF5, and HF10 specimens were etched for 20 s with acid concentrations of 1%, 3%, 5%, and 10%, respectively, while the SC (control) sample was untreated. The etched surfaces were evaluated using a scanning electron microscope and an atomic force microscope. Finally, the roughness was measured, and 3-point bending flexural tests were performed. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey's test (α = 0.05). The Weibull modulus and characteristic strength were also determined. No statistical difference in the roughness and flexural strength was determined among the groups. The structural reliabilities (Weilbull moduli) were similar for the tested groups; however, the characteristic strength of the HF1 specimen was greater than that of the HF10 specimen. Compared with the untreated ceramic, the surface roughness and flexural strength of the ceramic were unaffected upon etching, regardless of the acid concentration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 885-891, 2017. © 2016 Wiley Periodicals, Inc.

G-CSF loaded nanofiber/nanoparticle composite coated with collagen promotes wound healing in vivo.

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Tanha, Shima; Rafiee-Tehrani, Morteza; Abdollahi, Mohamad; Vakilian, Saeid; Esmaili, Zahra; Naraghi, Zahra Safaei; Seyedjafari, Ehsan; Javar, Hamid Akbari

2017-10-01

Sustained release of functional growth factors can be considered as a beneficial methodology for wound healing. In this study, recombinant human granulocyte colony-stimulating factor (G-CSF)-loaded chitosan nanoparticles were incorporated in Poly(ε-caprolactone) (PCL) nanofibers, followed by surface coating with collagen type I. Physical and mechanical properties of the PCL nanofibers containing G-CSF loaded chitosan nanoparticles PCL/NP(G-CSF) and in vivo performance for wound healing were investigated. G-CSF structural stability was evaluated through SDS_PAGE, reversed phase (RP) HPLC and size-exclusion chromatography, as well as circular dichroism. Nanofiber/nanoparticle composite scaffold was demonstrated to have appropriate mechanical properties as a wound dresser and a sustained release of functional G-CSF. The PCL/NP(G-CSF) scaffold showed a suitable proliferation and well-adherent morphology of stem cells. In vivo study and histopathological evaluation outcome revealed that skin regeneration was dramatically accelerated under PCL/NP(G-CSF) as compared with control groups. Superior fibroblast maturation, enhanced collagen deposition and minimum inflammatory cells were also the beneficial properties of PCL/NP(G-CSF) over the commercial dressing. The synergistic effect of extracellular matrix-mimicking nanofibrous membrane and G-CSF could develop a suitable supportive substrate in order to extensive utilization for the healing of skin wounds. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2830-2842, 2017. © 2017 Wiley Periodicals, Inc.

Multiarm-polyethylene glycol-polyglutamic acid peptide dendrimer: Design, synthesis, and dissolving thrombus.

Science.gov (United States)

Zhang, Shao-Fei; Lü, Shaoyu; Gao, Chunmei; Yang, Jiandong; Yan, Xiang; Li, Tao; Wen, Na; Huang, Mengjie; Liu, Mingzhu

2018-06-01

Thrombotic events affect many individuals in a number of ways, all of which can cause significant morbidity and mortality. Nattokinase (NK), as a novel thrombolytic drug, has been used for thrombolytic therapy. It not only possesses plasminogen activator activity, but also directly digests fibrin through limited proteolysis. However, it may undergo inactivation and denaturation in the harsh external environment. In this study, a multiarm-polyethylene glycol-polyglutamic acid peptide dendrimer was fabricated and used as a carrier for NK protection and delivery. Different arm numbers of polyethylene glycol-polyglutamic acid peptide dendrimers (x-PEG(G 3 ) x , x = 2, 4, 6, 8) were designed, prepared, and characterized by 1 H NMR and FTIR. Then, x-PEG(G 3 ) x were loaded with NK to form nanocomposites. Their size and morphology were determined by dynamic light scattering and transmission electron microscopy. Enzyme activity was evaluated via UV-Vis absorbance spectra, fluorescence spectra, circular dichroism spectra, and zeta potential measurements. The study reveals that the obtained x-PEG(G 3 ) x /NK nanocomposites possess high enzyme activity. In addition, the nanocomposites show increased viability of rat macrophage cells, and excellent thrombolysis ability in vitro and in vivo. This work establishes a multiarm-polyethylene glycol-polyglutamic acid peptide dendrimer with potential application in NK carrier and thrombolytic therapy. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1687-1696, 2018. © 2018 Wiley Periodicals, Inc.

Novel synthesis and characterization of an AB-type carbonate-substituted hydroxyapatite.

Science.gov (United States)

Gibson, Iain R; Bonfield, William

2002-03-15

A novel synthesis route has been developed to produce a high-purity mixed AB-type carbonate-substituted hydroxyapatite (CHA) with a carbonate content that is comparable to the type and level observed in bone mineral. This method involves the aqueous precipitation in the presence of carbonate ions in solution of a calcium phosphate apatite with a Ca/P molar ratio greater than the stoichiometric value of 1.67 for hydroxyapatite (HA). The resulting calcium-rich carbonate-apatite is sintered/heat-treated in a carbon dioxide atmosphere to produce a single-phase, crystalline carbonate-substituted hydroxyapatite. In contrast to previous methods for producing B- or AB-type carbonate-substituted hydroxyapatites, no sodium or ammonium ions, which would be present in the reaction mixture from the sodium or ammonium carbonates commonly used as a source of carbonate ions, were present in the final product. The chemical and phase compositions of the carbonate-substituted hydroxyapatite was characterized by X-ray fluorescence and X-ray diffraction, respectively, and the level and nature of the carbonate substitution were studied using C-H-N analysis and Fourier transform infrared spectroscopy, respectively. The carbonate substitution improves the densification of hydroxyapatite and reduces the sintering temperature required to achieve near-full density by approximately 200 degrees C compared to stoichiometric HA. Initial studies have shown that these carbonate-substituted hydroxyapatites have improved mechanical and biologic properties compared to stoichiometric hydroxyapatite. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 697-708, 2002

Biomimetic sulfated polyethylene glycol hydrogel inhibits proteoglycan loss and tumor necrosis factor-α-induced expression pattern in an osteoarthritis in vitro model.

Science.gov (United States)

Hemmati-Sadeghi, Shabnam; Dey, Pradip; Ringe, Jochen; Haag, Rainer; Sittinger, Michael; Dehne, Tilo

2018-04-16

This study aimed to evaluate the potential of an anti-inflammatory polyethylene glycol (PEG) hydrogel for osteoarthritis (OA) management in an OA in vitro model. Freshly isolated porcine chondrocytes were maintained in high-density cultures to form cartilage-like three-dimensional micromasses. Recombinant porcine tumor necrosis factor-alpha (TNF-α) was used to induce OA-like changes. Normal and OA-like micromasses were treated with dendritic polyglycerol sulfate-based PEG hydrogel. Live/dead staining showed that all micromasses remained vital and presented similar morphological characteristics. Safranin-O staining demonstrated a typical depletion of glycosaminoglycans in TNF-α-treated micromasses but not in the presence of the hydrogel. There was no distinct difference in immunohistochemical detection of type II collagen. Microarray data showed that rheumatoid arthritis and TNF signaling pathways were down regulated in hydrogel-treated OA-like micromasses compared to nontreated OA-like micromasses. The hydrogel alone did not affect genes related to OA such as ANPEP, COMP, CXCL12, PTGS2, and TNFSF10, but it prevented their regulation caused by TNF-α. This study provides valuable insights toward a fully synthetic hydrogel for the intra-articular treatment of OA. The findings proved the potential of this hydrogel to prevent the development of TNF-α-induced OA with regard to proteoglycan loss and TNF-α-induced expression pattern without additional signs of differentiation and inflammation. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Hydrostatic pressure in combination with topographical cues affects the fate of bone marrow-derived human mesenchymal stem cells for bone tissue regeneration.

Science.gov (United States)

Reinwald, Yvonne; El Haj, Alicia J

2018-03-01

Topographical and mechanical cues are vital for cell fate, tissue development in vivo, and to mimic the native cell growth environment in vitro. To date, the combinatory effect of mechanical and topographical cues as not been thoroughly investigated. This study investigates the effect of PCL nanofiber alignment and hydrostatic pressure on stem cell differentiation for bone tissue regeneration. Bone marrow-derived human mesenchymal stem cells were seeded onto standard tissue culture plastic and electrospun random and aligned nanofibers. These substrates were either cultured statically or subjected to intermittent hydrostatic pressure at 270 kPa, 1 Hz for 60 min daily over 21 days in osteogenic medium. Data revealed higher cell metabolic activities for all mechanically stimulated cell culture formats compared with non-stimulated controls; and random fibers compared with aligned fibers. Fiber orientation influenced cell morphology and patterns of calcium deposition. Significant up-regulation of Collagen-I, ALP, and Runx-2 were observed for random and aligned fibers following mechanical stimulation; highest levels of osteogenic markers were expressed when hydrostatic pressure was applied to random fibers. These results indicate that fiber alignment and hydrostatic pressure direct stem cell fate and are important stimulus for tissue regeneration. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: A: 629-640, 2018. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

Long-term liver-specific functions of hepatocytes in electrospun chitosan nanofiber scaffolds coated with fibronectin.

Science.gov (United States)

Rajendran, Divya; Hussain, Ali; Yip, Derek; Parekh, Amit; Shrirao, Anil; Cho, Cheul H

2017-08-01

In this study, a new 3D liver model was developed using biomimetic nanofiber scaffolds and co-culture system consisting of hepatocytes and fibroblasts for the maintenance of long-term liver functions. The chitosan nanofiber scaffolds were fabricated by the electrospinning technique. To enhance cellular adhesion and spreading, the surfaces of the chitosan scaffolds were coated with fibronectin (FN) by adsorption and evaluated for various cell types. Cellular phenotype, protein expression, and liver-specific functions were extensively characterized by immunofluorescent and histochemical stainings, albumin enzyme-linked immunosorbent assay and Cytochrome p450 detoxification assays, and scanning electron microscopy. The electrospun chitosan scaffolds exhibited a highly porous and randomly oriented nanofibrous structure. The FN coating on the surface of the chitosan nanofibers significantly enhanced cell attachment and spreading, as expected, as surface modification with this cell adhesion molecule on the chitosan surface is important for focal adhesion formation and integrin binding. Comparison of hepatocyte mono-cultures and co-cultures in 3D culture systems indicated that the hepatocytes in co-cultures formed colonies and maintained their morphologies and functions for prolonged periods of time. The 3D liver tissue model developed in this study will provide useful tools toward the development of engineered liver tissues for drug screening and tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2119-2128, 2017. © 2017 Wiley Periodicals, Inc.

Wear resistance of poly(2-methacryloyloxyethyl phosphorylcholine)-grafted carbon fiber reinforced poly(ether ether ketone) liners against metal and ceramic femoral heads.

Science.gov (United States)

Yamane, Shihori; Kyomoto, Masayuki; Moro, Toru; Hashimoto, Masami; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko

2018-04-01

Younger, active patients who undergo total hip arthroplasty (THA) have increasing needs for wider range of motion and improved stability of the joint. Therefore, bearing materials having not only higher wear resistance but also mechanical strength are required. Carbon fiber-reinforced poly(ether ether ketone) (CFR-PEEK) is known as a super engineering plastic that has great mechanical strength. In this study, we focused on poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted CFR-PEEK and investigated the effects of PMPC grafting and the femoral heads materials on the wear properties of CFR-PEEK liners. Compared with untreated CFR-PEEK, the PMPC-grafted CFR-PEEK surface revealed higher wettability and lower friction properties under aqueous circumstances. In the hip simulator wear test, wear particles generated from the PMPC-grafted CFR-PEEK liners were fewer than those of the untreated CFR-PEEK liners. There were no significant differences in the size and the morphology of the wear particles between the differences of PMPC-grafting and the counter femoral heads. Zirconia-toughened alumina (ZTA) femoral heads had significantly smoother surfaces compared to cobalt-chromium-molybdenum alloy femoral heads after the hip simulator test. Thus, we conclude that the bearing combination of the PMPC-grafted CFR-PEEK liner and ZTA head is expected to be a lifelong bearing interface in THA. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1028-1037, 2018. © 2017 Wiley Periodicals, Inc.

Degree of conversion and cross-link density within a resin-matrix composite.

Science.gov (United States)

Al-Zain, Afnan O; Eckert, George J; Lukic, Henry; Megremis, Spiro J; Platt, Jeffrey A

2018-05-01

The aims of this study were to profile light radiated from two light-curing units (LCUs) and evaluate profile relationship to polymerization patterns within a resin-matrix composite (RMC). Beam profiles of one multiple emission peak light-emitting-diode and one quartz-tungsten-halogen curing-unit were measured using a beam profiler/spectrometer system. A camera-based profiler and an integrating sphere/spectrometer assembly were used to evaluate each LCU beam. Polymerization patterns within a nano-hybrid RMC were investigated using a mapping approach by assessing the degree of conversion utilizing micro-Raman spectroscopy and indirectly estimating cross-link-density by repeated microhardness testing before and after exposure to ethanol (%KH reduction, n = 3). The irradiance received on the top and bottom specimen surfaces from both LCUs was measured using a MARC-RC system. The investigated beam profile area from both LCUs was non-uniform and yielded localized discrepancies in DC (55.7-74.9%) and %KH reduction (26.7-54.1%). The LCU irradiance received at the bottom of the specimens was ∼10% of the top value. This study demonstrated that LCU beam profiles were non-uniform in the area explored. Localized differences in DC and %KH reduction existed throughout the RMC specimens but did not follow a specific pattern. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1496-1504, 2018. © 2017 Wiley Periodicals, Inc.

In vitro cartilage construct generation from silk fibroin- chitosan porous scaffold and umbilical cord blood derived human mesenchymal stem cells in dynamic culture condition.

Science.gov (United States)

Agrawal, Parinita; Pramanik, Krishna; Biswas, Amit; Ku Patra, Ranjan

2018-02-01

Cartilage construct generation includes a scaffold with appropriate composition to mimic matrix of the damaged tissue on which the stem cells grow and differentiate. In this study, umbilical cord blood (UCB) derived human mesenchymal stem cells (hMSCs) were seeded on freeze dried porous silk-fibroin (SF)/chitosan (CS) scaffolds. Influence of static and dynamic (spinner flask bioreactor) culture conditions on the developing cartilage construct were studied by in-vitro characterization for viability, proliferation, distribution, and chondrogenic differentiation of hMSCs over the scaffold. Constructs developed in spinner flask consisted of 62% live cells, and exhibited 543% more cell density at the core than constructs cultured in static system. Quantification of DNA and glycosaminoglycans accumulation after 21 days showed the progression of chondrogenic differentiation of hMSCs was higher in dynamic culture compared to static one. In constructs generated under dynamic condition, histology staining for proteoglycan matrix, and fluorescence staining for collagen-II and aggrecan showed positive correlation between early and late stage chondrogenic markers, which was further confirmed by quantitative PCR analysis, showing low collagen-I expression and highly expressed Sox9, collagen-II and aggrecan. The present study demonstrated that construct generated by combining 3D SF/CS scaffold with UCB-hMSCs under dynamic condition using spinner flask bioreactor can be used for cartilage tissue regeneration for future medical treatments. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 397-407, 2018. © 2017 Wiley Periodicals, Inc.

Exploring the in vitro and in vivo compatibility of PLA, PLA/GNP and PLA/CNT-COOH biodegradable nanocomposites: Prospects for tendon and ligament applications.

Science.gov (United States)

Correia Pinto, Viviana; Costa-Almeida, Raquel; Rodrigues, Ilda; Guardão, Luísa; Soares, Raquel; Miranda Guedes, Rui

2017-08-01

Anterior cruciate ligament (ACL) reconstructive surgeries are the most frequent orthopedic procedures in the knee. Currently, existing strategies fail in completely restoring tissue functionality and have a high failure rate associated, presenting a compelling argument towards the development of novel materials envisioning ACL reinforcement. Tendons and ligaments, in general, have a strong demand in terms of biomechanical features of developed constructs. We have previously developed polylactic acid (PLA)-based biodegradable films reinforced either with graphene nanoplatelets (PLA/GNP) or with carboxyl-functionalized carbon nanotubes (PLA/CNT-COOH). In the present study, we comparatively assessed the biological performance of PLA, PLA/GNP, and PLA/CNT-COOH by seeding human dermal fibroblasts (HFF-1) and studying cell viability and proliferation. In vivo tests were also performed by subcutaneous implantation in 6-week-old C57Bl/6 mice. Results showed that all formulations studied herein did not elicit cytotoxic responses in seeded HFF-1, supporting cell proliferation up to 3 days in culture. Moreover, animal studies indicated no physiological signs of severe inflammatory response after 1 and 2 weeks after implantation. Taken together, our results present a preliminary assessment on the compatibility of PLA reinforced with GNP and CNT-COOH nanofillers, highlighting the potential use of these carbon-based nanofillers for the fabrication of reinforced synthetic polymer-based structures for ACL reinforcement. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2182-2190, 2017. © 2017 Wiley Periodicals, Inc.

Bilateral PLA/alginate membranes for the prevention of postsurgical adhesions.

Science.gov (United States)

Kessler, Martina; Esser, Eva; Groll, Jürgen; Tessmar, Jörg

2016-11-01

A bilateral barrier membrane for the prevention of postsurgical adhesions was developed. Thereby, a smooth PLA side was supposed to keep the affected tissues glidingly separated, while a mucoadhesive side made of alginate was meant to keep the barrier resident on the site of injury so that suturing becomes redundant or at least the membrane stays long enough to facilitate surgical handling. Because hydrophilic alginate and lipophilic PLA films show only low cohesion, solution electrospun meshes of PLA and PLA-PEG-PLA triblock copolymers with varying poly(ethylene glycol) [PEG] content were investigated as cohesion promoter to avoid an easy separation of the functionally different layers. Using direct electrospinning onto the PLA film, a modified contact surface of the mesh was created, which allowed the tested alginate solutions (3%, 5%) to infiltrate to different extents. Thereby, an increasing content of hydrophilic PEG within the mesh copolymer and a lower alginate concentration facilitated the infiltration. As a result, the PLA film with a PLA35k-PEG10k-PLA35k (racemic PLA chains) mesh and an alginate layer cast from a 3% alginate solution appeared to be the most effective combination as examined by means of a t peel test, a mucoadhesion test, a tensile test and optical evaluations. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1563-1570, 2016. © 2015 Wiley Periodicals, Inc.

Simulating economics and environmental impacts of beef and soybean systems in Brazil's Pamas and Amozon Biomes

Science.gov (United States)

Recent reductions in the deforestation of the Amazon biome have highlighted the need for the sustainable intensification of beef and commodity crop production in Brazil to increase agricultural productivity without accelerating adverse environmental impacts related to greenhouse gas emissions, eutro...

Dvořákova duchovní kantáta Stabat Mater a její uplatnění v koncertní síni, kostele i komické opeře

Czech Academy of Sciences Publication Activity Database

Kachlík, Jan

2015-01-01

Roč. 52, 3/4 (2015), s. 331-341 ISSN 0018-7003 Institutional support: RVO:68378076 Keywords : Antonín Dvořák * Stabat Mater * Šelma sedlák (The Cunning Peasant) * Sacred Cantata * Comic Opera Subject RIV: AL - Art, Architecture, Cultural Heritage

RES scintigraphy in polycythemia vera and secondary or relative polycythemia

Energy Technology Data Exchange (ETDEWEB)

Rudberg, U. (Depts. of Diagnostic Radiology and Internal Medicine, St. Goeran' s Hospital, Stockholm (Sweden)); Skaarberg, K.O. (Depts. of Diagnostic Radiology and Internal Medicine, St. Goeran' s Hospital, Stockholm (Sweden))

1993-03-01

Scintigraphy of the reticuloendothelial system (RES) was performed in 19 patients with polycythemia vera (PCV) and in 18 with secondary or relative polycythemia (PS). Bone marrow extension was found in all patients with PCV and in 11 of 18 patients with PS. The patients with PCV had a higher degree of extension than those with PS. Increased pelvic bone marrow activity was found in 16 of 19 PCV patients, but in none with PS. Splenomegaly was found in 9 patients with PCV, and in none with PS. It is concluded that RES scintigraphy in the majority of patients may differentiate between PCV and PS using the parameters pelvic bone marrow activity, bone marrow extension and splenic size. (orig.).

RES scintigraphy in polycythemia vera and secondary or relative polycythemia

International Nuclear Information System (INIS)

Rudberg, U.; Skaarberg, K.O.

1993-01-01

Scintigraphy of the reticuloendothelial system (RES) was performed in 19 patients with polycythemia vera (PCV) and in 18 with secondary or relative polycythemia (PS). Bone marrow extension was found in all patients with PCV and in 11 of 18 patients with PS. The patients with PCV had a higher degree of extension than those with PS. Increased pelvic bone marrow activity was found in 16 of 19 PCV patients, but in none with PS. Splenomegaly was found in 9 patients with PCV, and in none with PS. It is concluded that RES scintigraphy in the majority of patients may differentiate between PCV and PS using the parameters pelvic bone marrow activity, bone marrow extension and splenic size. (orig.)

Morphofunctional diversity of equine of varied genetic compositions raised in the Pantanal biome of Brazil.

Science.gov (United States)

de Rezende, Marcos Paulo Gonçalves; de Souza, Julio Cesar; Carneiro, Paulo Luiz Souza; Bozzi, Riccardo; Jardim, Rodrigo Jose Delgado; Malhado, Carlos Henrique Mendes

2018-06-01

Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal's size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding.

Clonality analysis of lymphoid proliferations using the BIOMED-2 clonality assays: a single institution experience

Science.gov (United States)

Kokovic, Ira; Novakovic, Barbara Jezersek; Cerkovnik, Petra; Novakovic, Srdjan

2014-01-01

Background Clonality determination in patients with lymphoproliferative disorders can improve the final diagnosis. The aim of our study was to evaluate the applicative value of standardized BIOMED-2 gene clonality assay protocols for the analysis of clonality of lymphocytes in a group of different lymphoid proliferations. Materials and methods. With this purpose, 121 specimens from 91 patients with suspected lymphoproliferations submitted for routine diagnostics from January to December 2011 were retrospectively analyzed. According to the final diagnosis, our series comprised 32 cases of B-cell lymphomas, 38 cases of non-Hodgkin’s T-cell lymphomas and 51 cases of reactive lymphoid proliferations. Clonality testing was performed using the BIOMED-2 clonality assays. Results The determined sensitivity of the TCR assay was 91.9%, while the sensitivity of the IGH assay was 74.2%. The determined specificity of the IGH assay was 73.3% in the group of lymphomas and 87.2% in the group of reactive lesions. The determined specificity of the TCR assay was 62.5% in the group of lymphomas and 54.3% in the group of reactive lesions. Conclusions In the present study, we confirmed the utility of standardized BIOMED-2 clonality assays for the detection of clonality in a routine diagnostical setting of non-Hodgkin’s lymphomas. Reactions for the detection of the complete IGH rearrangements and reactions for the detection of the TCR rearrangements are a good choice for clonality testing of a wide range of lymphoid proliferations and specimen types while the reactions for the detection of incomplete IGH rearrangements have not shown any additional diagnostic value. PMID:24991205

Birth of a biome: insights into the assembly and maintenance of the Australian arid zone biota.

Science.gov (United States)

Byrne, M; Yeates, D K; Joseph, L; Kearney, M; Bowler, J; Williams, M A J; Cooper, S; Donnellan, S C; Keogh, J S; Leys, R; Melville, J; Murphy, D J; Porch, N; Wyrwoll, K-H

2008-10-01

The integration of phylogenetics, phylogeography and palaeoenvironmental studies is providing major insights into the historical forces that have shaped the Earth's biomes. Yet our present view is biased towards arctic and temperate/tropical forest regions, with very little focus on the extensive arid regions of the planet. The Australian arid zone is one of the largest desert landform systems in the world, with a unique, diverse and relatively well-studied biota. With foci on palaeoenvironmental and molecular data, we here review what is known about the assembly and maintenance of this biome in the context of its physical history, and in comparison with other mesic biomes. Aridification of Australia began in the Mid-Miocene, around 15 million years, but fully arid landforms in central Australia appeared much later, around 1-4 million years. Dated molecular phylogenies of diverse taxa show the deepest divergences of arid-adapted taxa from the Mid-Miocene, consistent with the onset of desiccation. There is evidence of arid-adapted taxa evolving from mesic-adapted ancestors, and also of speciation within the arid zone. There is no evidence for an increase in speciation rate during the Pleistocene, and most arid-zone species lineages date to the Pliocene or earlier. The last 0.8 million years have seen major fluctuations of the arid zone, with large areas covered by mobile sand dunes during glacial maxima. Some large, vagile taxa show patterns of recent expansion and migration throughout the arid zone, in parallel with the ice sheet-imposed range shifts in Northern Hemisphere taxa. Yet other taxa show high lineage diversity and strong phylogeographical structure, indicating persistence in multiple localised refugia over several glacial maxima. Similar to the Northern Hemisphere, Pleistocene range shifts have produced suture zones, creating the opportunity for diversification and speciation through hybridisation, polyploidy and parthenogenesis. This review highlights

Power utility generation portfolio optimization as function of specific RES and decarbonisation targets – EPBiH case study

International Nuclear Information System (INIS)

Kazagic, Anes; Merzic, Ajla; Redzic, Elma; Music, Mustafa

2014-01-01

Highlights: • Guidelines for power utilities to reach specific decarbonisation targets offered. • Optimization model of RES share to be introduced into power system is proposed. • Single criteria analysis and multicriteria sustainability assessment are applied. • The optimization method has been demonstrated on a real power system. • In the considered case, HIGH RES scenario showed to be the preferable one. - Abstract: This paper provides guidelines and principles for power utilities to reach specific energy and decarbonisation targets. Method of power generation portfolio optimization, as function of sustainability and decarbonisation, along with appropriate criteria, has been proposed. Application of this optimization method has been demonstrated on a real power system – power utility JP Elektroprivreda BiH d.d. – Sarajevo (EPBiH), a typical example of South East European power system. The software tool WASP IV has been employed in the analysis, in order to define the dynamics and an optimized expansion of generation portfolio of the power system under consideration for the next period. The mid-term generation portfolio development plan for the EPBiH power system until year 2030 has been made during this research, taking into account the shutdown dynamics of existing power units and commissioning new ones, in order to provide safe supply of electric and heat energy for local consumers. Three basic scenario of renewable energy sources (RES) expansion have been analysed to reach specific RES and decarbonisation targets set for 2030, including RES share increase from the current level of 18% up to 35% (LOW RES), 45% (MID RES) and 55% (HIGH RES). Effects to the sustainability are considered through environmental, economic and social indicators. Multicriteria sustainability assessment gave an advantage to the HIGH RES, under assumption of equal weighting factors of economic and environment groups of indicators. Also, single criteria analysis has been

Reply: “Use of BIOME-BGC to simulate Mediterranean forest carbon stocks”

OpenAIRE

Maselli F; Salvati R; Barbati A; Chirici G; Chiesi M

2011-01-01

The current note responds to the critical contribution of Dr. Eastaugh on Chiesi et al. (Chiesi et al. 2011). That paper did not aim at applying BIOME-BGC to simulate stand growth, which requires a thorough modification of the model functions. In contrast, only a parameter setting was changed in order to adjust the predicted carbon storages during the simulation of quasi-equilibrium conditions. The adjustment was calibrated on volume statistics derived from the Tuscany forest inventory and is...

Genetic diversity of bats coronaviruses in the Atlantic Forest hotspot biome, Brazil.

Science.gov (United States)

Góes, Luiz Gustavo Bentim; Campos, Angélica Cristine de Almeida; Carvalho, Cristiano de; Ambar, Guilherme; Queiroz, Luzia Helena; Cruz-Neto, Ariovaldo Pereira; Munir, Muhammad; Durigon, Edison Luiz

2016-10-01

Bats are notorious reservoirs of genetically-diverse and high-profile pathogens, and are playing crucial roles in the emergence and re-emergence of viruses, both in human and in animals. In this report, we identified and characterized previously unknown and diverse genetic clusters of bat coronaviruses in the Atlantic Forest Biome, Brazil. These results highlight the virus richness of bats and their possible roles in the public health. Copyright © 2016 Elsevier B.V. All rights reserved.

Proposta de um desenho da cadeia reversa para resíduos eletroeletrônicos

Directory of Open Access Journals (Sweden)

Reinaldo Alves de Sá Ferreira Júnior

2016-12-01

Full Text Available Com o crescimento da demanda dos equipamentos eletroeletrônicos e de sua rápida obsolescência, gera-se grande volume de resíduos, os quais possuem metais pesados altamente tóxicos, como o mercúrio, cobre, chumbo, arsênio, entre outros. A implantação da Logística Reversa (LR tem sido uma forma de gestão de grande sucesso, tanto no contexto internacional como nacional, e aliada a Politica Nacional de Resíduos Sólidos (PNRS tornou-se uma forma mais eficaz para o gerenciamento desses resíduos. Este artigo teve como objetivo, a partir da revisão na literatura referente à LR, PNRS e REEE apresentar atores, atribuições e processos associados, propondo, desta forma, uma estrutura geral para a cadeia de suprimentos reversa de pós-consumo associada aos REEE. A principal contribuição do artigo é proposição de um desenho da cadeia reversa para resíduos Eletroeletrônicos.

Pettumus Res Publicas algas kirikus antud vandest / Margus Tsahkna

Index Scriptorium Estoniae

Tsahkna, Margus, 1977-

2005-01-01

Autori sõnul on Res Publica petnud inimeste põhiväärtustele tuginevaid ootusi, Eesti riik kaugeneb kodanikust ja tema elulistest huvidest. Isamaaliit paneb ette asuda tegelike probleemide lahendamisele ning kutsub erakondi üles kaitsma rahvuslikke huve

L’identification biométrique : vers un nouveau contrôle social ? Biometric Identification: a New Social Control?

Directory of Open Access Journals (Sweden)

Gérard Dubey

2011-02-01

Full Text Available La biométrie se définit aujourd’hui comme la possibilité d’identifier sur la base de critères purement techniques un individu dans une masse et dans des flux. Elle est indissociable du processus d’informatisation de la société et de l’impéra­tif de traçabilité (des signes, des choses et aujourd’hui des êtres vivants qu’im­pose le recouvrement du monde réel par son image numérique contrôlée et contrôlable. Le déploiement des dispositifs d’identification biométrique illustre ainsi la convergence qui s’opère entre la logique étatique du contrôle à distance et la logique propre au Macro-Système-Technique. Telle est la première thèse défendue dans cet article qui interroge ensuite le type de contrôle et de pouvoir induit par ces nouvelles modalités. La thèse d’un nouveau contrôle social est discutée depuis les données empiriques recueillies auprès des premiers usagers de ces dispositifs et son déterminisme est mis en cause. Le contrôle social auto­matisé, qui épouse les contours du Macro-Système-Technique, mime les mou­vements de la société réelle plus qu’il ne les contrôle. En cela réside sa limite.Biometry is defined today as the possibility of identifying an individual on the basis of purely technical criteria in a mass and in flux. It is indissociable from the process of digitalization of the society and the imperative of traceability (signs, things and today living beings imposed by the covering of the real world by its controlled and controllable numerical image. The spread of biometric identification mechanisms thus illustrates the convergence in operation between the State logic of long-distance control and the logic proper to Technical-Macro-Systems. That is the first thesis defended in this article, which then asks about the type of control and power exercised by these new means. The thesis of a new social control is discussed based on the empirical data gathered among the

The Response Regulator ResD Plays a Role in Metabolism of Listeria monocytogenes

DEFF Research Database (Denmark)

Larsen, Marianne Halberg; Sørensen, Martine; Ingmer, Hanne

to be transmitted to food processing plants from where it can establish and survive for extended periods of time contaminating processed food products. Recently we have identified the response regulator ResD of L. monocytogenes and showed that it is important for growth in laboratory media and for sugar uptake...... in the upstream regulatory region of several genes of L. monocytogenes and the binding of the ResD protein to some of these regulatory regions upstream putative target genes is analysed by electrophoretic mobility shift assays (EMSAs). In conclusion, the response regulator ResD act is important for metabolisme...

Valorização de resíduos em materiais de construção

OpenAIRE

Pinho, Paulo André Martins de

2014-01-01

O trabalho desenvolvido nesta dissertação enquadra-se no objetivo geral de valorização de resíduos provenientes de unidades de pasta Kraft de eucalipto, nomeadamente cinzas de fundo e cinzas volantes das fornalhas de biomassa. Atualmente uma das mais graves preocupações das sociedades dos países desenvolvidos passa por encontrar um destino adequado para resíduos gerados. A construção civil, aliada com a indústria da produção de pasta e papel que por ano gera milhares de toneladas de resídu...