187 research outputs found
Cephalometric studies of the mandible, its masticatory muscles and vasculature of growing Göttingen Minipigs — A comparative anatomical study to refine experimental mandibular surgery
Over many decades, the Göttingen Minipig has been used as a large animal model in experimental surgical research of the mandible. Recently several authors have raised concerns over the use of the Göttingen Minipig in this research area, observing problems with post-operative wound healing and loosening implants. To reduce these complications during and after surgery and to improve animal welfare in mandibular surgery research, the present study elucidated how comparable the mandible of minipigs is to that of humans and whether these complications could be caused by specific anatomical characteristics of the minipigs’ mandible, its masticatory muscles and associated vasculature. Twenty-two mandibular cephalometric parameters were measured on CT scans of Göttingen Minipigs aged between 12 and 21 months. Ultimately, we compared this data with human data reported in the scientific literature. In addition, image segmentation was used to determine the masticatory muscle morphology and the configuration of the mandibular blood vessels. Compared to data of humans, significant differences in the mandibular anatomy of minipigs were found. Of the 22 parameters measured only four were found to be highly comparable, whilst the others were not. The 3D examinations of the minipigs vasculature showed a very prominent deep facial vein directly medial to the mandibular ramus and potentially interfering with the sectional plane of mandibular distraction osteogenesis. Damage to this vessel could result in inaccessible bleeding. The findings of this study suggest that Göttingen Minipigs are not ideal animal models for experimental mandibular surgery research. Nevertheless if these minipigs are used the authors recommend that radiographic techniques, such as computed tomography, be used in the specific planning procedures for the mandibular surgical experiments. In addition, it is advisable to choose suitable age groups and customize implants based on the mandibular dimensions reported in this study
Conservation of long-range synteny and microsynteny between the genomes of two distantly related nematodes
BACKGROUND: Comparisons between the genomes of the closely related nematodes Caenorhabditis elegans and Caenorhabditis briggsae reveal high rates of rearrangement, with a bias towards within-chromosome events. To assess whether this pattern is true of nematodes in general, we have used genome sequence to compare two nematode species that last shared a common ancestor approximately 300 million years ago: the model C. elegans and the filarial parasite Brugia malayi. RESULTS: An 83 kb region flanking the gene for Bm-mif-1 (macrophage migration inhibitory factor, a B. malayi homolog of a human cytokine) was sequenced. When compared to the complete genome of C. elegans, evidence for conservation of long-range synteny and microsynteny was found. Potential C. elegans orthologs for II of the 12 protein-coding genes predicted in the B. malayi sequence were identified. Ten of these orthologs were located on chromosome I, with eight clustered in a 2.3 Mb region. While several, relatively local, intrachromosomal rearrangements have occurred, the order, composition, and configuration of two gene clusters, each containing three genes, was conserved. Comparison of B. malayi BAC-end genome survey sequence to C. elegans also revealed a bias towards intrachromosome rearrangements. CONCLUSIONS: We suggest that intrachromosomal rearrangement is a major force driving chromosomal organization in nematodes, but is constrained by the interdigitation of functional elements of neighboring genes
Fire impact on forest soils evaluated using near-infrared spectroscopy and multivariate calibration
L'évaluation des propriétés physicochimiques des sols forestiers affectés par des feux a été réalisée en utilisant la spectroscopie proche infra-rouge (SPIR) couplée avec des méthodes chimiométriques. Pour décrire les propriétés du sol, les mesures prises comprennent le carbone organique total sur phase solide, le contenu d'azote total, le carbone organique et l'absorbance spécifique à 254 et 280nm des substances humiques, le carbone organique dans des acides humiques et fulviques, des concentrations de NH4+, Ca2+, Mg2+, K+ et le phosphore en plus des spectres de PIR. Un indice de répétition d'incendies a été défini et calculé selon les régimes de feux affectant des sols. Ce calcul inclut l'occurrence des incendies et le temps écoulé depuis le dernier feu. Cette étude montre que la spectroscopie PIR pourrait être utilisée pour le contrôle de qualité des sols, particulièrement pour la prédiction quantitative du carbone organique total, l'azote total, le carbone organique dans les substances humiques, les concentrations de phosphore, Mg2 +, Ca2 + et NH4 + et des substances humiques UVSA254. Une nouvelle validation dans ce domaine est nécessaire cependant pour une bonne prédictions de K+, du carbone organique dans des acides humiques et fulviques et les substances humiques UVSA280. De plus, la SPIR couplée avec la régression PLS peut aussi être utile pour prévoir l'indice de répétition de feu et pour déterminer sa variabilité spatiale. Aussi cette méthode peut être utilisée pour dresser la carte de secteurs plus ou moins brûlés et pour adapter les techniques de réhabilitation, comme la reconstitution de l'humus avec des enrichissements organiques (composts) ou le reboisement. Finalement, on peut considérer que notre indice de répétition est représentatif de l'état des sols. / The assessment of physico-chemical properties in forest soils affected by fires was evaluated using near infrared reflectance (NIR) spectroscopy coupled with chemometric methods. In order to describe the soil properties, measurements were taken of the total organic carbon on solid phase, the total nitrogen content, the organic carbon and the specific absorbences at 254 and 280nm of humic substances, organic carbon in humic and fulvic acids, concentrations of NH4+, Ca2+,Mg2+, K+ and phosphorus in addition to NIR spectra. Then, a fire recurrence index was defined and calculated according to the different fires extents affecting soils. This calculation includes the occurrence of fires as well as the time elapsed since the last fire. This study shows that NIR spectroscopy could be considered as a tool for soil monitoring, particularly for the quantitative prediction of the total organic carbon, total nitrogen content, organic carbon in humic substances, concentrations of phosphorus, Mg2+, Ca2+ and NH4+ and humic substances UVSA254. Further validation in this field is necessary however, to try and make successful predictions of K+, organic carbon in humic and fulvic acids and the humic substances UVSA280. Moreover, NIR coupled with PLS can also be useful to predict the fire recurrence index in order to determine the spatial variability. Also this method can be used to map more or less burned areas and possibly to apply adequate rehabilitation techniques, like soil litter reconstitution with organic enrichments (industrial composts) or reforestation. Finally, the proposed recurrence index can be considered representative of the state of the soils
Dual acting therapeutic proteins for intraocular use
Antibody-based medicines that target vascular endothelial growth factor (VEGF) are administered by intravitreal injection to treat chronic neovascular retinal diseases. Much ongoing effort is focused on enhancing therapeutic outcome of these medicines. One strategy is the use of dual acting drugs (e.g. bispecific antibodies) to simultaneously bind to more than one intraocular biological target. A dual acting molecule targeting components within the vitreal cavity could also potentially extend vitreous residence time. In this review, the applications of bispecific antibodies within the eye are described with consideration to potential targets, applications and suitable bispecific formats
Computer memories: the history of computer form
This paper looks at the computer as a truly global form. The similar beige boxes found in offices across the world are analysed from the perspective of design history rather than that of the history of science and technology. Through the exploration of an archive of computer manufacturer's catalogues and concurrent design texts, this paper examines the changes that have occurred in the production and consumption of the computer in the context of the workplace, from its inception as a room-sized mainframe operated through a console of flashing lights, to the personal computer as a 'universal' form, reproduced by many manufacturers. It shows how the computer in the past has been as diverse as any other product, and asks how and why it now appears as a standardised, sanitised object. In doing so our relationship with the office computer, past and present is explored, revealing a complex history of vicissitude.</p
Vaccination with novel low-molecular weight proteins secreted from Trichinella spiralis inhibits establishment of infection
Trichinella spiralis muscle stage larvae (mL1) produce excretory-secreted products (ESPs), a complex mixture of protein, which are believed to be important for establishing or maintaining an infection niche within skeletal muscle and the intestine. Studies of both whole ESPs and individual cloned proteins have shown that some ESPs are potent immunogens capable of eliciting protective immune responses. Here we describe two novel proteins, Secreted from Muscle stage Larvae SML-4 and SML-5 which are 15 kDa and 12 kDa respectively. The genes encoding these proteins are highly conserved within the Trichinellids, are constituents of mL1 ESP and localized in the parasite stichosome. While SML-5 is only expressed in mL1 and early stages of adult nematode development, SML-4 is a tyvosylated glycoprotein also produced by adult nematodes, indicating it may have a function in the enteral phase of the infection. Vaccination with these proteins resulted in an impaired establishment of adult stages and consequently a reduction in the burden of mL1 in BALB/c mice. This suggests that both proteins may be important for establishment of parasite infection of the intestine and are prophylactic vaccine candidates
Evaluating impact of truck announcements on container stacking efficiency
Container stacking rules are an important factor in container terminal efficiency. We build on prior research and use a discrete-event simulation model to evaluate the impact of a truck announcement system on the performance of online container stacking rules. The information that is contained in the announcement, i.e., the expected departure time for an import container, can be used to schedule pre-emptive remarshall moves. These moves can then be performed when the workload is low in order to decrease the export time and the crane workload at peak times
Characterizations and rheological study of the purified polysaccharide extracted from quince seeds
Identificación y análisis de la variabilidad morfológica de 59 cultivares de papa criolla (solanum phureja juz. et buk.)
La identificación de la diversidad morfológica de 59 cultivaresde Solanum phureja Juz. el Buk. Se realizó mediante los descriptores estandarizados por el CIP (Centro Internacional de la Papa) en 1994. Los datos se tomaron a partir de los cultivares establecidos en los centros de investigación Tibaitatá y San Jorge, ubicados en los municipios de Mosquera y Soacha respectivamente; los datos fueronsometidos a análisis simples y multivariados tales como: correlación, componentes principales, análisis cluster y análisis de escalamiento multidimensional. Los primeros 10 componentes principales expresaron el 76% de la variabilidad total, mientras el análisis cluster y de escalamiento multidimensional discriminaron los cultivares en ocho grupos Los análisis multivariados mostraron que las variables más importantes para la caracterización e identificación de los grupos son: V25 forma general del tubérculo, V26 formas raras del tubérculo, V18 color primario de la piel del tubérculo, V20 color secundario de la piel del tubérculo, V34 grado de floración y V9 pigmentación del pistilo.The goal of this research was to identify the morphologicaldiversity of 59 genotypes of Solanum phureja Juz. el Buk.According to the descriptors of the CIP (lnternational PotatoCenter) the data were evaluated in two research centers of Corpoica (Mosquera) and ICA (Soacha) villages. The data was analyzed through simple and multivariate statistics such as: correlation, principal components, cluster, and multidimensional analyses. The first ten principal components give 76% of the total variability. The cluster analysis and multidimensional scaling refereed eight genotypes groups. The multivariate analysis showed the most important variables for the characterization and identification, whichwere (V25 tuber's general shapes), V26 (tuber's races shapes), V18 (tuber's skin primary color), V20 (tuber's skin secondary color), V34 (flowering level) and V9 (pistil pigmentation)
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