962 resultados para LYMPHOCYTIC INFILTRATION
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The purpose of this study was to evaluate the efficacy of a Coulomb Controlled Iontophoresis system (CCI) in the local delivery of corticosteroids for the treatment of uveitis. The therapeutic efficacy of Dexamethasone (Dex) administered by CCI was compared to systemic injection and to topical application with the iontophoresis apparatus in the absence of electrical current. The evaluation was done in the treatment of the endotoxin-induced uveitis (EIU) model, and in the effect on TNF gene expression in the iris/ciliary body as well as in the retina and on TNF levels in aqueous humor and vitreous. Dex was administered either at the time of LPS injection or 5 hours later. For iontophoresis, we used a 1 ml reservoir-electrode covering the cornea, the limbus, and the first millimeter of the sclera. The applied electrical current was of 400 microA during four minutes with a total surface charge of 0.4 C cm-2. EIU was evaluated by clinical examination, by counts of intraocular inflammatory cells on histological sections, and by measuring the protein levels in the aqueous humor and in the vitreous. The TNF-alpha gene expression in the iris and ciliary body, and in the retina was evaluated by RT-PCR. The systemic effect of Dex delivered by CCI was evaluated on the level of serum TNF-alpha in EIU. Our results demonstrated that local administration of Dex by CCI inhibited anterior and posterior signs of intraocular inflammation as effectively as systemic administration, with no effect on systemic level of TNF. In the anterior and posterior segments of the eye, the protein exudation. TNF levels and the cellular infiltration were inhibited. The TNF-alpha gene expression was inhibited in the anterior as well as the posterior segment of the eye. No clinical nor histological damage were caused by the CCI apparatus. In conclusion, CCI administration of Dex allows for a therapeutic effect on the posterior as well as the anterior segment of the eye, and may present a viable alternative to systemic administration of glucocorticoids in severe ocular inflammations.
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Les crues et les risques de débordement des barrages, notamment des digues en terre, en cas de fortes précipitations, préoccupent depuis longtemps les autorités et la population. Les études réalisées dans les dernières années ont montré que le réchauffement global du climat s'est accompagné d'une augmentation de la fréquence des fortes précipitations et des crues en Suisse et dans de nombreuses régions du globe durant le 20ème siècle. Les modèles climatiques globaux et régionaux prévoient que la fréquence des fortes précipitations devrait continuer à croître durant le 21éme siècle en Suisse et dans le monde. Cela rend les recherches actuelles sur la modélisation des pluies et des crues à une échelle fine encore plus importantes. En Suisse, pour assurer une bonne protection sur le plan humain et économique, des cartes de précipitations maximales probables (PMP) ont été réalisées. Les PMP ont été confrontées avec les précipitations extrêmes mesurées dans les différentes régions du pays. Ces PMP sont ensuite utilisées par les modèles hydrologiques pour calculer des crues maximales probables (PMF). Cette la méthode PMP-PMF nécessite toutefois un certain nombre de précautions. Si elle est appliquée d'une manière incorrecte ou sur la base de données insuffisantes, elle peut entraîner une surestimation des débits de crue, notamment pour les grands bassins et pour les régions montagneuses entraînant des surcoûts importants. Ces problèmes résultent notamment du fait que la plupart des modèles hydrologiques répartissent les précipitations extrêmes (PMP) de manière uniforme dans le temps sur l'ensemble du bassin versant. Pour remédier ce problème, cette thèse a comme objectif principal de développer un modèle hydrologique distribué appelé MPF (Modeling Precipitation Flood) capable d'estimer la PMF de manière réaliste à partir de la PMP distribuée de manière spatio-temporelle à l'aide des nuages. Le modèle développé MPF comprend trois parties importantes. Dans la première partie, les précipitations extrêmes calculées par un modèle météorologique à une méso-échelle avec une résolution horizontale de 2 km, sont réparties à une échelle locale (25 ou 50 m) de manière non-uniforme dans l'espace et dans le temps. La deuxième partie concerne la modélisation de l'écoulement de l'eau en surface et en subsurface en incluant l'infiltration et l'exfiltration. Et la troisième partie inclut la modélisation de la fonte des neiges, basée sur un calcul de transfert de chaleur. Le modèle MPF a été calibré sur des bassins versants alpins où les données de précipitations et du débit sont disponibles pour une période considérablement longue, qui inclut plusieurs épisodes de fortes pluies avec des débits élevés. À partir de ces épisodes, les paramètres d'entrée du modèle tel que la rugosité du sol et la largeur moyenne des cours d'eau dans le cas d'écoulement de surface ont pu être estimés. Suivant la même procédure, les paramètres utilisés dans la simulation des écoulements en subsurface sont également estimés indirectement, puisque des mesures directes de l'écoulement en subsurface et de l'exfiltration sont difficiles à obtenir. Le modèle de distribution spatio-temporelle de la pluie a aussi été validé en utilisant les images radar avec la structure de la pluie provoquée par un nuage supercellulaire. Les hyétogrammes obtenus sur plusieurs points du terrain sont très proches de ceux enregistrées avec les images radar. Les résultats de la validation du modèle sur les épisodes de fortes crues présentent une bonne synchronisation entre le débit simulé et le débit observé. Cette corrélation a été mesurée avec trois critères d'efficacité, qui ont tous donné des valeurs satisfaisantes. Cela montre que le modèle développé est valide et il peut être utilisé pour des épisodes extrêmes tels que la PMP. Des simulations ont été faites sur plusieurs bassins ayant comme données d'entrée la pluie de type PMP. Des conditions variées ont été utilisées, comme la situation du sol saturé, ou non-saturé, ou la présence d'une couche de neige sur le terrain au moment de la PMP, ce qui conduit à une estimation de PMF pour des scénarios catastrophiques. Enfin, les résultats obtenus montrent comment mieux estimer la valeur de la crue de sécurité des barrages, à partir d'une pluie extrême dix-millennale avec une période de retour de 10'000 ans.
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The infiltration of river water into aquifers is of high relevance to drinking-water production and is a key driver of biogeochemical processes in the hyporheic and riparian zone, but the distribution and quantification of the infiltrating water are difficult to determine using conventional hydrological methods (e.g., borehole logging and tracer tests). By time-lapse inverting crosshole ERT (electrical resistivity tomography) monitoring data, we imaged groundwater flow patterns driven by river water infiltrating a perialpine gravel aquifer in northeastern Switzerland. This was possible because the electrical resistivity of the infiltrating water changed during rainfall-runoff events. Our time-lapse resistivity models indicated rather complex flow patterns as a result of spatially heterogeneous bank filtration and aquifer heterogeneity. The upper part of the aquifer was most affected by the river infiltrate, and the highest groundwater velocities and possible preferential flow occurred at shallow to intermediate depths. Time series of the reconstructed resistivity models matched groundwater electrical resistivity data recorded on borehole loggers in the upper and middle parts of the aquifer, whereas the resistivity models displayed smaller variations and delayed responses with respect to the logging data. in the lower part. This study demonstrated that crosshole ERT monitoring of natural electrical resistivity variations of river infiltrate could be used to image and quantify 3D bank filtration and aquifer dynamics at a high spatial resolution.
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SUMMARY The results presented here contribute to a better understanding of the crucial molecular relationships and signalling cues exchanged by several fundamental cell types (epidermal keratinocytes, dermal fibroblasts, immune and endothelial cells) of the skin. Importantly we provide evidence to directly implicate Wnt/ß-catenin signalling as a putative player in different cell types (keratinocytes and neutrophils) in mediation of the cutaneous inflammatory response (Fart A). Finally we highlight the importance of several molecules, specifically expressed in the hair follicle stem cell niche to the morphogenesis and homeostasis of the hair follicle (Part B). PART A Currently the body of work pertaining to Wnt signalling and immune cells largely focuses on Wnt signalling in the development of these cells. The data presented here suggests a novel mechanism in which Wnt signalling appears to modulate immune cell recruitment to the skin. Keratinocytes are major contributors to early inflammatory responses by the release of chemokines which recruit immune cells. The resultant inflammatory response is a dynamic process of sequentially infiltrating immune cells governed by a network of growth factors, chemokines and cytokines. In wild type mice the response is typified by a rapid and substantial infiltration of neutrophils followed at later time points by macrophages and Tcells. The expression of the canonical Wnt pathway activating ligand, Wnt3a, is able to induce a strong neutrophil infiltration in the dermis. This response originates in keratinocytes, as it is abrogated upon keratinocyte-specific ablation of ß-catenin. Notably, this suggests that the crucial cross talk between these resident cells and recruited immune cells is, in part, mediated by Wnt signalling. In corroboration of this role of Wnt-mediated recruitment of neutrophils, expression of the Wnt inhibitory ligand sFRPI during acute inflammation results in a dramatic 'dampening' of immune cell infiltration in particular of neutrophil chemoattraction. Importantly, an intrinsic Wnt signalling pathway is essential for neutrophil chemoattraction in response to inflammatory stimuli. There is a marked reduction of neutrophil infiltration in mice grafted with a ß-catenin deficient bone marrow upon TPA induced cutaneous inflammation. Additionally, neutrophils lacking Wnt/ß-catenin fail to respond to IFNγ, an early inflammatory cue, in vitro. In combination, these data indicate a potent function of Wnt signalling in immune cell recruitment and the modulation of the inflammatory response. PART B Tissue specific stem cells form the cellular base on which tissue homeostasis and repair of adult tissue relies. The maintenance of this stem cell pool is highly dependent on the immediate environment or niche. We have identified three genes, the fibroblast growth factor receptor 1 (FGFR1), serpin protease inhibitor (serpin F1) and the haematopoietic cell phosphatase (Hcph) to be specifically expressed in a small population of stromal cells which are in close contact to bulge stem cells. These specialized stromal cells might represent an essential mesenchymal component of the skin stem cell niche and may regulate stem cell proliferation and differentiation. Multiple FGFR1 isoforms are generated through alternate transcript splicing and are able to interact with both FGFs and cell adhesion molecules. Two predominant forms of the receptor are FGFR1-α and FGFR1-ß. Expression of a dominant negative form of the alpha isoform prevents hair follicle morphogenesis altogether. Given that FGFR1-ß signals principally through the FGF ligands, this data indicates that FGF signalling is dispensable for follicle morphogenesis. Moreover the loss of follicular morphogenesis upon suggests a requirement for signalling via cell adhesion molecule association with the receptor as FGFR1 α has a greater affinity for these molecules. The expression of the second candidate niche gene serpin f1, lead to the complete ablation of hair follicle morphogenesis. The serpin f1 product, pigment-epithelial derived factor (PEDF) has potent anti-angiogenic effects. Immunohistochemical analysis using CD31, a endothelial cell marker, revealed that although these cells are present, they have are disorganised and do not form vessels. Interestingly, endothelial cells have been found to contribute to the neuronal stem cell niche and our results suggest a similar mechanism in the skin. SHP1, the Hcph gene product, is a phosphatase which acts in the haematopoetic system. Motheaten mice carrying spontaneous mutations in the Hcph gene have patchy alopecia in their skin and severe defects in their haematopoietic system. However the haematopoietic rescue of the mouse does not result in normal follicular homeostasis. Additionally, ablation of Hcph in either the dermal or keratinocyte compartments of the skin produces hair follicles with abberant morphologies. This data indicates that although SHP1 is not essential for hair follicle morphogenesis it is required in both epidermal and dermal compartments to maintain follicular morphology. RÉSUMÉ PARTIE A Jusqu'à présent, les travaux dédiés à l'étude de la voie de signalisation Wnt dans le système immunitaire se sont essentiellement concentrés sur son rôle dans le développement des cellules immunitaires. Les données présentées ici suggèrent fortement et de manière nouvelle, l'existence d'un mécanisme par lequel la voie de signalisation Wnt/ß-caténine module le recrutement de cellules immunitaires dans un tissu périphérique, la peau, et ainsi la réponse inflammatoire cutanée. La réponse inflammatoire cutanée est un processus dynamique d'infiltration séquentielle de diverses cellules immunitaires, orchestré par un réseau de facteurs de croissance, chémokines et cytokines. Les kératinocytes sont des contributeurs majeurs à la réponse inflammatoire précoce par la libération de chémokines qui permettent ensuite de recruter les cellules immunitaires. Dans des souris sauvages, la réponse est d'abord caractérisée par une infiltration rapide et substantielle de neutrophiles, suivie par celle des macrophages et des lymphocytes T. L'expression d'un ligand activateur de le voie canonique de signalisation Wnt (après injection infra-dermique de fibroblastes sur-exprimant Wnt-3a) induit une infiltration dermique très marquée de neutrophiles. De plus, la réponse est éliminée en l'absence de ß-caténine spécifiquement dans les kératinocytes, indiquant que ces cellules sont à l'origine de la réponse. De manière remarquable, ceci suggère qu'une signalisation cruciale entre ces cellules résidentes de la peau et les cellules immunitaires recrutées est, au moins en partie, médiée par la voie Wnt. Corroborant ce rôle de la voie Wnt/ß-caténine dans le recrutement des neutrophiles, l'expression d'un ligand inhibiteur de la voie (sFRP1) résulte au cours d'une inflammation aigüe en une réduction spectaculaire de l'infiltration des cellules immunitaires en général, et des neutrophiles en particulier. De manière importante, la voie de signalisation Wnt est intrinsèquement requise pour la chémoattraction des neutrophiles en réponse à un stimulus inflammatoire. En effet, suite à une inflammation cutanée induite par un ester de phorbol (TPA), une réduction notable de l'infiltration des neutrophiles est observée dans des souris préalablement greffées avec de la moelle osseuse constituée de cellules déficientes en ß-caténine. De plus, in vitro, les neutrophiles sans ß-caténine ne répondent pas à une stimulation par l'interféron γ, qui est pourtant un signal inflammatoire établi in vivo. En conclusion, nos données indiquent que la voie de signalisation Wnt/ß-caténine joue une fonction active dans le recrutement des cellules immunitaires vers un organe périphérique, la peau, ainsi que dans la modulation, à plusieurs niveaux, de la réponse inflammatoire cutanée. PARTIE B Les cellules souches tissu-spécifiques forment la base cellulaire sur laquelle repose l'homéostase et la réparation tissulaires chez l'adulte. La maintenance de ce réservoir de cellules souches est hautement dépendante de leur environnement cellulaire immédiat, encore appelé «niche des cellules souches». Dans la peau, ces cellules stromales spécialisées représentent un compartiment mésenchymateux essentiel de la niche des cellules souches en régulant leurs prolifération et différentiation. Nous avons identifié trois gènes, le «récepteur 1 àux facteurs de croissance des fibroblastes » (Fgfr1 ), l' «inhibiteur de protéase à sérine » (serpinf1 ou pedf) et la « phosphatase des cellules hématopoiétiques » (Hcph ou Ptpn6), comme spécifiquement exprimés par une petite population de cellules stromales qui sont étroitement associées aux cellules souches de la peau (localisées au niveau du bombement du follicule pileux). Pour analyser leur fonction dans ce contexte, nous avons utilisé un test de reconstitution complète de peau murine en combinaison à des. transductions géniques basées sur l'utilisation de lentivirus. Ce test repose sur le mélange de deux compartiments cellulaires, épidermique (kératinocytes) et dermique (fibroblastes), greffés sur une zone ouverte de peau du dos d'une souris pour ensemble reconstituer la peau. Des isoformes multiples de FGFR1 sont générées par épissage alternatif de transcrits et sont capables d'interagir à la fois avec les FGFs (facteurs de croissance des fibroblastes) et les molécules d'adhésion cellulaires. Les deux formes prédominantes du récepteur, FGFR1-α et FGFR1-ß, ne différent que par le «domaine ressemblant aux immunoglobulines 1 » (immunoglobulin-like 1 domain), absent de FGFR1-ß. De plus, FGFR1-ß a une affinité plus grande pour les FGFs et plus faible pour les molécules d'adhésion cellulaires telles que la Ncadhérine (connue pour activer FGFR). La sur-expression de l'une ou l'autre des formes n'empêche pas la morphogenèse folliculaire mais conduit à la formation de follicules aberrants. Toutefois, une différence phénotypique majeure est observée lorsqu'une forme «Dominant-Négatif » (DN) est exprimée dans le compartiment dermique. La sur-expression de FGFR1-ß DN conduit en effet à la formation de follicules petits et tronqués, avec des gaines épithéliales et un bulbe élargis ainsi qu'une petite papille dermique. Par contre, l'expression de FGFR1-α DN abolit complètement la morphogenèse folliculaire. Etant donné que la signalisation par FGFR1-ß est principalement dépendante des ligands FGFs, ces données indiquent que la signalisation par ceux-cì est non-nécessaire à la morphogenèse folliculaire. De plus, l'abolition du processus par la sur-expression de FGFR1-a DN suggëre une signalisation nécessaire entre le récepteur FGFR1 et une ou des molécules d'adhésion cellulaire. L'expression de notre second candidat comme gène spécifique de la niche des cellules souches de la peau, serpinf1, prévient la morphogenèse folliculaire. Seules de petites structures ressemblant à des cystes sont observées après reconstitution de la peau. De plus, dans ces transplants, aucune cellule CD34-positive (marqueur des cellules souches) n'est retrouvée associé à ces cystes. Le produit du gène serpin f1, le «facteur dérivé d'épithélium pigmentaire » (PEDF) est un puissant facteur anti-angiogénique. Nous avons donc analysé la vascularisation des transplants par immunohistochirnies utilisant CD31, un marqueur des cellules endothéliales. Nos résultats révèlent que les cellules endothéliales sont bien présentes, mais de manière désorganisée et ne formant pas de vaisseaux. De manière intéressante, les cellules endothéliales contribuent activement à la niche des cellules souches neuronales, et nos résultats suggèrent donc l'existence possible d'un mécanisme similaire dans la peau. SHP1, le produit du gène Hcph, est une phosphatase quì agit dans le système hématopoiétique. Les souris « motheaten »qui portent des mutations spontanées du gène ont une alopécie inégale au niveau de la peau et de sévères troubles du système hématopoiétique. Pour s'assurer que le phénotype observé au niveau de la peau n'est pas une conséquence d'un défaut du système hématopoiétique, nous avons transplanté des souris Hcph -/- avec de la moelle osseuse sauvage afin de restaurer la fonction de SHP 1 dans le système hématopoiétique. Toutefois, le défaut de morphologie folliculaire est maintenu. De plus, l'ablation d'Hcph dans le compartiment dermique ou épidermique d'essais de reconstitution de peau conduit à la production de follicules pileux avec des morphologies aberrantes. Ces données indiquent que SHP1 n'est pas essentiel à la morphogenèse folliculaire mais est toutefois requis à la fois dans les compartiments épidermiques et dermiques pour la maintenance de la forme du follicule.
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This article presents a modification of intraoperative external fixation for mandibular reconstruction with free tissue flaps. This technique is indicated when preregistration of the reconstruction plate is not possible due to transmandibular tumor extension. Once standard external fixation has been carried out and prior to segmental mandibulectomy, additional pins are fixed to the connecting rod that delineate the mandibular contour in three-dimensional (3D) space. Following mandibulectomy, these pins allow accurate contouring of the reconstruction plate and improved restoration of mandibular contour, projection, and dental occlusion. A step-by-step description of the technique using models and intraoperative photos is presented. This method of mandibular reconstruction is a simple and time-effective alternative to intraoperative computer navigation and 3D modeling in select cases of oral carcinoma where tumor infiltration of the outer mandibular cortex precludes prebending of the reconstruction plates.
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Early in the 1990s, several case series described adults suffering from dysphagia and children with refractory reflux symptoms, both accompanied by an eosinophil-predominant infiltration, thereby conclusively distinguishing it from gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) was recognized as its own entity in the adult and in the pediatric literature. In the last decade, evidence has accumulated that EoE represents a T-helper (Th)2-type inflammatory disease. Remodeling of the esophagus is a hallmark of EoE, leading to esophageal dysfunction and bolus impaction. Familial occurrence and disease association with single-nucleotide polymorphisms underscore the influence of genetics in this disease. Eosinophilic esophagitis may affect individuals at any age, although the clinical presentation is highly age dependent. There is a significant allergic bias in the EoE population, with the majority of patients having concurrent allergic rhinitis, asthma, eczema, and/or a history of atopy. One noteworthy difference is that in children, EoE seems to be primarily a food antigen-driven disease, whereas in adults, mainly aeroallergen sensitization has been observed. Treatment modalities for EoE include the 3Ds: drugs, diet, and dilation. The crucial question of whether adult and pediatric EoE are different phenotypes of one single entity or whether we are confronted with two different diseases is still open. Here, we review similarities and differences between EoE in adults and children.
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Portland cement pervious concrete (PCPC) is being used more frequently due to its benefits in reducing the quantity of runoff water,improving water quality, enhancing pavement skid resistance during storm events by rapid drainage of water, and reducing pavement noise. In the United States, PCPC typically has high porosity and low strength, which has resulted in the limited use of pervious concrete, especially in hard wet freeze environments (e.g., the Midwestern and Northeastern United States and other parts of the world).Improving the strength and freeze-thaw durability of pervious concrete will allow an increase in its use in these regions. The objective of this research is to develop a PCPC mix that not only has sufficient porosity for stormwater infiltration, but also desirable strength and freeze-thaw durability. In this research, concrete mixes were designed with various sizes and types of aggregates, binder contents, and admixture amounts. The engineering properties of the aggregates were evaluated. Additionally, the porosity, permeability, strength, and freeze-thaw durability of each of these mixes was measured. Results indicate that PCPC made with single-sized aggregate has high permeability but not adequate strength. Adding a small percent of sand to the mix improves its strength and freeze-thaw resistance, but lowers its permeability. Although adding sand and latex improved the strength of the mix when compared with single-sized mixes, the strength of mixes where only sand was added were higher. The freeze-thaw resistance of PCPC mixes with a small percentage of sand also showed 2% mass loss after 300 cycles of freeze-thaw. The preliminary results of the effects of compaction energy on PCPC properties show that compaction energy significantly affects the freeze-thaw durability of PCPC and, to a lesser extent, reduces compressive strength and split strength and increases permeability.
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BACKGROUND: The envelope glycoprotein of lymphocytic choriomeningitis virus (LCMV) can efficiently pseudotype lentiviral vectors. Some strains of LCMV exploit high affinity interactions with α-dystroglycan (α-DG) to bind to cell surfaces and subsequently fuse in low pH endosomes. LCMV strains with low α-DG affinity utilize an unknown receptor and display unique tissue tropisms. We pseudotyped non-primate feline immunodeficiency virus (FIV) vectors using LCMV derived glycoproteins with high or low affinity to α-DG and evaluated their properties in vitro and in vivo. METHODS: We pseudotyped FIV with the LCMV WE54 strain envelope glycoprotein and also engineered a point mutation in the WE54 envelope glycoprotein (L260F) to diminish α-DG affinity and direct binding to alternate receptors. We hypothesized that this change would alter in vivo tissue tropism and enhance gene transfer to neonatal animals. RESULTS: In mice, hepatic α- and β-DG expression was greatest at the late gestational and neonatal time points. When displayed on the surface of the FIV lentivirus the WE54 L260F mutant glycoprotein bound weakly to immobilized α-DG. Additionally, LCMV WE54 pseudotyped FIV vector transduction was neutralized by pre-incubation with soluble α-DG, while the mutant glycoprotein pseudotyped vector was not. In vivo gene transfer in adult mice with either envelope yielded low transduction efficiencies in hepatocytes following intravenous delivery. In marked contrast, neonatal gene transfer with the LCMV envelopes, and notably with the FIV-L260F vector, conferred abundant liver and lower level cardiomyocyte transduction as detected by luciferase assays, bioluminescent imaging, and β-galactosidase staining. CONCLUSIONS: These results suggest that a developmentally regulated receptor for LCMV is expressed abundantly in neonatal mice. LCMV pseudotyped vectors may have applications for neonatal gene transfer. ABBREVIATIONS: Armstrong 53b (Arm53b); baculovirus Autographa californica GP64 (GP64); charge-coupled device (CCD); dystroglycan (DG); feline immunodeficiency virus (FIV); glycoprotein precursor (GP-C); firefly luciferase (Luc); lymphocytic choriomeningitis virus (LCMV); nuclear targeted β-galactosidase (ntLacZ); optical density (OD); PBS/0.1% (w/v) Tween-20 (PBST); relative light units (RLU); Rous sarcoma virus (RSV); transducing units per milliliter (TU/ml); vesicular stomatitis virus (VSV-G); wheat germ agglutinin (WGA); 50% reduction in binding (C50).
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The objective of this work was to assess the effects of a forest-field ecotone on earthworm assemblages. Five sites (blocks) differing in the type of crop rotation used in the field were studied in Central Bohemia, Czech Republic. In each block, sampling was carried out in seven parallel rows perpendicular to a transect from a forest (oak or oak-pine) to the centre of a field, both in spring and autumn 2001-2003. Individual rows were located in the forest (5 m from the edge), in the forest edge, and in the field (at 5, 10, 25, 50 and 100 m distances from the forest edge). The density and biomass of earthworms were lowest in the forest, increased markedly in the forest edge, decreased again at 5 or 10 m distance from the forest edge and then continuously increased along the distance to the field boundary. The highest number of species was found in the forest edge and in the field boundary. Individual species differed in their distribution along the transect. Both density and biomass of earthworms were correlated with distance from forest edge, soil organic matter content, soil porosity, and water infiltration rate.
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With this application, the College Creek sub-watershed in Ames represents both regional collaboration and locally directed action to improve an Iowa watershed. Already completed watershed assessment identified more than 4000 tons/yr of sediment delivered from within the Ames city limits due to degraded stream conditions. The water quality enhancement goal of this project is reducing sediment delivery specifically from unstable streambanks and degrading stream channels on College Creek, one of 4 Ames tributaries to Squaw Creek. The project will also redirect urban storm water runoff into engineered infiltration systems, intercepting it from storm drains entering College Creek. This application builds on storm water runoff demonstration projects and research already funded in the College Creek sub-watershed by EPA Region 7 and Iowa DNR. Public outreach, one of the key elements of this project, is built into every phase from engineering design feedback to construction. Innovative neighborhood learning circles are utilized to educate residents and share public feedback with project engineers to ensure that project elements are both technically appropriate and socially acceptable. All practices proposed in this project -stream stabilization, storm water infiltration, and neighborhood learning circle techniques-have already been successfully demonstrated in the College Creek sub-watershed by the City of Ames in partnership with Iowa State University.
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Competine Creek is an 8,653 acre subwatershed of Whitebreast Creek which drains directly to Lake Red Rock. The Marion Soil and Water Conservation District has prioritized water quality protection efforts within Competine Creek subwatershed because 1) this watershed has been identified as a significant contributor of sediment, nutrients, and bacteria to Competine Creek and Lake Red Rock, 2) the watershed provides unique outreach opportunities due to its unique rural and urban interface, and 3) by using a targeted approach to address water quality, the likelihood of successfully demonstrating water quality improvements is high due to its manageable size. The specific goals of this proposal to WIRB (Phase I) are to: 1) reduce sediment and nutrient delivery by 1787 tons and 2144 lbs by installing conservation practices on high priority agricultural land; and 2) install urban conservation practices that reduce the volume of peak flow, improve streambank stability, and promote infiltration of stormwater runoff before it enters Competine Creek. The Marion SWCD has assembled a unique group of partners and secured funding from multiple sources to implement this project.
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The City of Remsen is proactively addressing an increase of nitrates in their public water supply before it becomes a financial catastrophe for them. An intensive assessment was conducted by the Iowa DNR Source Water Protection program as one of four pilot projects in the state. This assessment far surpassed standard desktop assessments and gathered monitoring information in-the-field led by a local watershed group. This was incorporated into a computer modeling program to help the local watershed group discuss alternatives. This comprehensive approach clearly identified the source of nitrate infiltration as a cropland area adjacent to the City well field. Many options were evaluated but only one option provided an economical, viable and secure answer to the water supply needs of Remsen for generations to come. The watershed planning group chose to seek the purchase of this critical area of cropland and convert it to a deep rooted mixture of native grasses. This WIRB funding is intended to be used to acquire a small area totaling 21.1 acres. It represents about 22% of the total local project effort. This will be added to the existing City well field of 40.2 acres and another piece of adjacent property, 35.34 acres, that the City recently acquired as part of an overall aggressive program to protect the community water supply. The City has a signed purchase agreement for 14.4 acres of the 21.1 and a strong verbal commitment to obtain the remaining 5.7 acres. This project has been very active for almost 2 years and is ready to implement immediately upon funding notification. The establishment of native grasses, funded by the local chapter of Pheasants Forever, will take approximately the next three years of operation & maintenance.
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A crucial step in the life cycle of arenaviruses is the biosynthesis of the mature fusion-active viral envelope glycoprotein (GP) that is essential for virus-host cell attachment and entry. The maturation of the arenavirus GP precursor (GPC) critically depends on proteolytic processing by the cellular proprotein convertase (PC) subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P). Here we undertook a molecular characterization of the SKI-1/S1P processing of the GPCs of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) and the pathogenic Lassa virus (LASV). Previous studies showed that the GPC of LASV undergoes processing in the endoplasmic reticulum (ER)/cis-Golgi compartment, whereas the LCMV GPC is cleaved in a late Golgi compartment. Herein we confirm these findings and provide evidence that the SKI-1/S1P recognition site RRLL, present in the SKI-1/S1P prodomain and LASV GPC, but not in the LCMV GPC, is crucial for the processing of the LASV GPC in the ER/cis-Golgi compartment. Our structure-function analysis revealed that the cleavage of arenavirus GPCs, but not cellular substrates, critically depends on the autoprocessing of SKI-1/S1P, suggesting differences in the processing of cellular and viral substrates. Deletion mutagenesis showed that the transmembrane and intracellular domains of SKI-1/S1P are dispensable for arenavirus GPC processing. The expression of a soluble form of the protease in SKI-I/S1P-deficient cells resulted in the efficient processing of arenavirus GPCs and rescued productive virus infection. However, exogenous soluble SKI-1/S1P was unable to process LCMV and LASV GPCs displayed at the surface of SKI-I/S1P-deficient cells, indicating that GPC processing occurs in an intracellular compartment. In sum, our study reveals important differences in the SKI-1/S1P processing of viral and cellular substrates.
Resumo:
Dry Run Creek Watershed was designated an impaired waterbody by DNR in 2002, following an assessment of the biota in the stream by DNR Biologist, Tom Wilton. Subsequent studies by IOWATER Snapshot effort in 2003, found e-coli bacteria concentrations and high nitrate readings in excess of the State of Iowa limits for recreational streams. The Dry Run Creek Watershed Improvement Project is comprised of five major components. Three components will feature demonstrations of structural best management practices (BMPs) to protect water quality in Dry Run Creek. The fourth is an educational workshop to "kick-off" the initiative and background the stakeholders of the watershed in new stormwater management strategies for water quality protection. The fifth is a monitoring program that will provide data on the effectiveness of the practices to be demonstrated. Measurable outcomes from these projects include monitoring to document the effectiveness of infiltration based BMPs to reduce pollutant loading in urban stormwater runoff and reducing the volume of stormwater discharged directly into Dry Run Creek via storm sewer flows. Understanding of and social acceptance of new stormwater strategies and practices will also be monitored by surveys of watershed stakeholders and compared to findings of a survey done before the start of the project.
Resumo:
The purpose of this project is to develop a management plan to address the City of Alta’s stormwater runoff. Currently, there is no management plan and the city is growing, so there are increased runoff problems from both residential and industrial sources. A large assortment of pollutants flow from these areas, examples include various forms of sediment, paper, plastic, gravel and metal as well as less visible potentially toxic pollution from lawns, streets, gas stations and other commercial and industrial areas. The goal for this project is to construct two infiltration/detention basins to protect water quality and reduce the peak volume of the City of Alta’s urban runoff. Each basin is designed with two functions: Control gully erosion and surface erosion with detention, while incorporating water quality through infiltration. The downstream erosion control provided by detaining runoff will reduce sediment delivery to Powell Creek and protect downstream agricultural land from urban runoff. The infiltration features designed into the basins will capture pollutants commonly associated with urban stormwater runoff such as: sediment, sand, gravel hydrocarbons, particulate matter, heavy metals, and nutrients.