244 research outputs found
Controllability and controller-observer design for a class of linear time-varying systems
“The final publication is available at Springer via http://dx.doi.org/10.1007/s10852-012-9212-6"In this paper a class of linear time-varying control systems is considered. The time variation consists of a scalar time-varying coefficient multiplying the state matrix of an otherwise time-invariant system. Under very weak assumptions of this coefficient, we show that the controllability can be assessed by an algebraic rank condition, Kalman canonical decomposition is possible, and we give a method for designing a linear state-feedback controller and Luenberger observer
Deficiency and Also Transgenic Overexpression of Timp-3 Both Lead to Compromised Bone Mass and Architecture In Vivo
Tissue inhibitor of metalloproteinases-3 (TIMP-3) regulates extracellular matrix via its inhibition of matrix metalloproteinases and membrane-bound sheddases. Timp-3 is expressed at multiple sites of extensive tissue remodelling. This extends to bone where its role, however, remains largely unresolved. In this study, we have used Micro-CT to assess bone mass and architecture, histological and histochemical evaluation to characterise the skeletal phenotype of Timp-3 KO mice and have complemented this by also examining similar indices in mice harbouring a Timp-3 transgene driven via a Col-2a-driven promoter to specifically target overexpression to chondrocytes. Our data show that Timp-3 deficiency compromises tibial bone mass and structure in both cortical and trabecular compartments, with corresponding increases in osteoclasts. Transgenic overexpression also generates defects in tibial structure predominantly in the cortical bone along the entire shaft without significant increases in osteoclasts. These alterations in cortical mass significantly compromise predicted tibial load-bearing resistance to torsion in both genotypes. Neither Timp-3 KO nor transgenic mouse growth plates are significantly affected. The impact of Timp-3 deficiency and of transgenic overexpression extends to produce modification in craniofacial bones of both endochondral and intramembranous origins. These data indicate that the levels of Timp-3 are crucial in the attainment of functionally-appropriate bone mass and architecture and that this arises from chondrogenic and osteogenic lineages
Digit Ratio Predicts Sense of Direction in Women
The relative length of the second-to-fourth digits (2D:4D) has been linked with prenatal androgen in humans. The 2D:4D is sexually dimorphic, with lower values in males than females, and appears to correlate with diverse measures of behavior. However, the relationship between digit ratio and cognition, and spatial cognition in particular, has produced mixed results. In the present study, we hypothesized that spatial tasks separating cue conditions that either favored female or male strategies would examine this structure-function correlation with greater precision. Previous work suggests that males are better in the use of directional cues than females. In the present study, participants learned a target location in a virtual landscape environment, in conditions that contained either all directional (i.e., distant or compass bearing) cues, or all positional (i.e., local, small objects) cues. After a short delay, participants navigated back to the target location from a novel starting location. Males had higher accuracy in initial search direction than females in environments with all directional cues. Lower digit ratio was correlated with higher accuracy of initial search direction in females in environments with all directional cues. Mental rotation scores did not correlate with digit ratio in either males or females. These results demonstrate for the first time that a sex difference in the use of directional cues, i.e., the sense of direction, is associated with more male-like digit ratio.National Science Foundation (U.S.) (NSF ECCS-1028319)National Science Foundation (U.S.) (NSF Graduate Student Fellowship)Mary Elisabeth Rennie Endowment for Epilepsy Researc
Molecular diagnosis of Pseudoterranova decipiens s.s in human, France
Background: Anisakis and Pseudoterranova are the main genera involved in human infections caused by nematodes
of the Anisakidae family. Species identification is complicated due to the lack of differential morphological
characteristics at the larval stage, thus requiring molecular differentiation. Pseudoterranova larvae ingested through
raw fish are spontaneously eliminated in most cases, but mechanical removal by means of endoscopy might be
required. To date, only very few cases of Pseudoterranova infection have been reported in France.
Case presentation: A 19-year-old woman from Northeastern France detected, while brushing her teeth, a larva
exiting through her mouth. The patient who presented with headache, diarrhea, and abdominal cramps reported
having eaten baked cod. The worm was a fourth-stage larva with a size of 22 × 0.9 mm, and molecular
biology identified it as Pseudoterranova decipiens sensu stricto (s. s.). In a second P. decipiens infection case, occurring a
few months later, a worm exited through the patient’s nose after she had eaten raw sea bream.
Conclusion: These two cases demonstrate that Pseudoterranova infection is not uncommon among French patients.
Therefore, molecular techniques should be more widely applied for a better characterization of anisakidosis epidemiology
in France
In Vitro Evaluation of Enterococcus faecalis Adhesion on Various Endodontic Medicaments
E. faecalis in endodontic infection represents a biofilm type of disease, which explains the bacteria’s resistance to various antimicrobial compounds and the subsequent failure after endodontic treatment. The purpose of this study was to compare antimicrobial activities and bacteria kinetic adhesion in vitro for three endodontic medicaments with a clinical isolate of E. faecalis. We devised a shake culture which contained the following intracanalar preparations: CPD, Endoidrox (EIX), PulpCanalSealer (PCS); these were immersed in a liquid culture medium inoculated with the microorganism. The shake system velocity was able to prevent non-specific bacteria adhesion and simulated the salivary flow. Specimens were collected daily (from both the medium and medicaments) for 10 days; the viable cells were counted by plate count, while the adhesion index AI° [E. faecalis fg DNA] /mm2 was evaluated in the pastes after DNA extraction, by quantitative real time PCR for the 16S rRNA gene. A partial growth inhibition, during the first 24 hours, was observed in the liquid medium and on the medicaments for EIX and subsequently for CPD (six logs). EIX showed the lowest adhesion coefficient (5*102 [fg DNA]/mm2) for nine days and was similar to the control. PCS showed no antimicrobial/antibiofilm properties. This showed that “calcium oxide” base compounds could be active against biofilm progression and at least in the short term (2-4 days) on E. faecalis cells growing in planktonic cultures
Genetic Diversity of Mycobacterium tuberculosis Isolates from Tibetans in Tibet, China
BACKGROUND: Tuberculosis (TB) is a serious health problem in Tibet where Tibetans are the major ethnic group. Although genotyping of Mycobacterium tuberculosis (M. tuberculosis) isolates is a valuable tool for TB control, our knowledge of population structure of M. tuberculosis circulating in Tibet is limited. METHODOLOGY/PRINCIPAL FINDINGS: In our study, a total of 576 M. tuberculosis isolates from Tibetans in Tibet, China, were analyzed via spoligotyping and 24-locus MIRU-VNTR. The Beijing genotype was the most prevalent family (90.63%, n = 522). Shared-type (ST) 1 was the most dominant genotype (88.89%, n = 512). We found that there was no association between the Beijing genotype and sex, age and treatment status. In this sample collection, 7 of the 24 MIRU-VNTR loci were highly or moderately discriminative according to their Hunter-Gaston discriminatory index. An informative set of 12 loci had similar discriminatory power with 24 loci set. CONCLUSIONS/SIGNIFICANCE: The population structure of M. tuberculosis isolates in Tibetans is homogeneous and dominated by Beijing genotype. The analysis of 24-locus MIRU-VNTR data might be useful to select appropriate VNTR loci for the genotyping of M. tuberculosis
iTRAQ Identification of Candidate Serum Biomarkers Associated with Metastatic Progression of Human Prostate Cancer
A major challenge in the management of patients with prostate cancer is identifying those individuals at risk of developing metastatic disease, as in most cases the disease will remain indolent. We analyzed pooled serum samples from 4 groups of patients (n = 5 samples/group), collected prospectively and actively monitored for a minimum of 5 yrs. Patients groups were (i) histological diagnosis of benign prostatic hyperplasia with no evidence of cancer ‘BPH’, (ii) localised cancer with no evidence of progression, ‘non-progressing’ (iii) localised cancer with evidence of biochemical progression, ‘progressing’, and (iv) bone metastasis at presentation ‘metastatic’. Pooled samples were immuno-depleted of the 14 most highly abundant proteins and analysed using a 4-plex iTRAQ approach. Overall 122 proteins were identified and relatively quantified. Comparisons of progressing versus non-progressing groups identified the significant differential expression of 25 proteins (p<0.001). Comparisons of metastatic versus progressing groups identified the significant differential expression of 23 proteins. Mapping the differentially expressed proteins onto the prostate cancer progression pathway revealed the dysregulated expression of individual proteins, pairs of proteins and ‘panels’ of proteins to be associated with particular stages of disease development and progression. The median immunostaining intensity of eukaryotic translation elongation factor 1 alpha 1 (eEF1A1), one of the candidates identified, was significantly higher in osteoblasts in close proximity to metastatic tumour cells compared with osteoblasts in control bone (p = 0.0353, Mann Whitney U). Our proteomic approach has identified leads for potentially useful serum biomarkers associated with the metastatic progression of prostate cancer. The panels identified, including eEF1A1 warrant further investigation and validation
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