2,209 research outputs found

    Isolation of polymorphic microsatellites in the stemless thistle (Cirsium acaule) and their utility in other Cirsium species

    Get PDF
    The genus Cirsium includes species with both widespread and restricted geographical distributions, several of which are serious weeds. Nine polymorphic microsatellite loci were isolated from the stemless thistle Cirsium acaule. Eight were polymorphic in C. acaule, six in C. arvense and seven in C. heterophyllum. One locus monomorphic in C. acaule showed polymorphism in C. heterophyllum. The mean number of alleles per locus was 4.1 in C. acaule, 6.2 in C. arvense and 2.9 in C. heterophyllum. These nine loci were also amplified in C. eriophorum and C. vulgare, suggesting that these markers may be of use throughout the genus

    Reporting Outcomes of Extremely Preterm Births

    Get PDF
    Published reports of extremely preterm birth outcomes provide important information to families, clinicians, and others and are widely used to make clinical and policy decisions. Misreporting or misunderstanding of outcome reports may have significant consequences. This article presents 7 recommendations to improve reporting of extremely preterm birth outcomes in both the primary and secondary literature. The recommendations should facilitate clarity in communication about extremely preterm birth outcomes and increase the value of existing and future work in this area

    Morphology and hemodynamics in isolated common iliac artery aneurysms impacts proximal aortic remodeling

    Get PDF
    Objective- Isolated common iliac artery aneurysms (CIAA) are rare. Their prognosis and influence on aortoiliac blood flow and remodeling are unclear. We evaluated the hypotheses that morphology at and distal to the aortic bifurcation, together with the associated hemodynamic changes, influence both the natural history of CIAA and proximal aortic remodeling. Approach and Results- Twenty-five isolated CIAAs (15 intact, 10 ruptured), in 23 patients were reconstructed and analyzed with computational fluid dynamics: all showed abnormal flow. Then we studied a series of 24 hypothetical aortoiliac geometries in silico with varying abdominal aortic deflection and aortic bifurcation angles: key findings were assessed in an independent validation cohort of 162 patients. Wall shear stress in isolated unilateral CIAAs was lower than the contralateral common iliac artery, 0.38±0.33 Pa versus 0.61±0.24 Pa, inversely associated with CIAA diameter ( P<0.001) and morphology (high shear stress in variants distal to a sharp kink). Rupture usually occurred in regions of elevated low and oscillatory shear with a wide aortic bifurcation angle. Abdominal aortas deflected towards the CIAA for most unilateral isolated CIAAs (14/21). In silico, wider bifurcation angles created high focal regions of low and oscillatory shear in the common iliac artery. The associations of unilateral CIAA with aortic deflection and common iliac artery diameter with bifurcation angle were confirmed in the validation cohort. Conclusions- Decreasing wall shear stress is strongly associated with CIAA progression (larger aneurysms and rupture), whereas abnormal blood flow in the CIAA seems to promote proximal aortic remodeling, with adaptive lateral deflection of the abdominal aorta towards the aneurysmal side

    Clinical biological and genetic heterogeneity of the inborn errors of pulmonary surfactant metabolism

    Get PDF
    Pulmonary surfactant is a multimolecular complex located at the air-water interface within the alveolus to which a range of physical (surface-active properties) and immune functions has been assigned. This complex consists of a surface-active lipid layer (consisting mainly of phospholipids), and of an aqueous subphase. From discrete surfactant sub-fractions one can isolate strongly hydrophobic surf acta nt proteins B (SP-B) and C (SP-C) as well as collectins SP-A and SP-D, which were shown to have specific structural, metabolic, or immune properties. Inborn or acquired abnormalities of the surfactant, qualitative or quantitative in nature, account for a number of human diseases. Beside hyaline membrane disease of the preterm neonate, a cluster of hereditary or acquired lung diseases has been characterized by periodic acid-Schiff-positive material filling the alveoli. From this heterogeneous nosologic group, at least two discrete entities presently emerge. The first is the SP-B deficiency, in which an essentially proteinaceous material is stored within the alveoli, and which represents an autosomal recessive Mendelian entity linked to the SFTPB gene (MIM 1786640). The disease usually generally entails neonatal respiratory distress with rapid fatal outcome, although partial or transient deficiencies have also been observed. The second is alveolar proteinosis, characterized by the storage of a mixed protein and lipid material, which constitutes a relatively heterogeneous clinical and biological syndrome, especially with regard to age at onset (from the neonate through to adulthood) as well as the severity of associated signs. Murine models, with a targeted mutation of the gene encoding granulocyte macrophage colony-stimulating factor (GM-CSF) (Csfgm) or the beta subunit of its receptor (II3rb1) support the hypothesis of an abnormality of surfactant turnover in which the alveolar macrophage is a key player. Apart from SP-B deficiency, in which a near-consensus diagnostic chart can be designed, the ascertainment of other abnormalities of surfactant metabolism is not straightforward. The disentanglement of this disease cluster is however essential to propose specific therapeutic procedures: repeated broncho-alveolar ravages, GM-CSF replacement, bone marrow grafting or lung transplantation

    The incidence of scarring on the dorsum of the hand

    Get PDF
    When undertaking image comparison of the hand between accused and perpetrator, it is not unusual for scars to be identified on the back of the hand. To investigate the occurrence of scarring in a discreet sample, a database of 238 individuals was examined, and the dorsum of the right and left hands was gridded for each individual. The position, size and type of scar were recorded within each grid. It was found that, in general, males exhibited a higher incidence of scarring than females. However, males were more likely to show scarring on their left hand whereas females were more likely to exhibit scarring on their right hand. Contrary to the literature, scarring was not most prevalent along the borders of the hand but occurred more frequently in association with the index and middle finger corridor regions. Surgical scars were rare as were large scars whereas linear scars smaller than 6 mm were the most frequently identified. Close to half of the sample did not exhibit scarring on one hand. The importance of understanding the pattern of scarring on the back of the hand is discussed in the light of forensic image comparison analysis

    Information heat engine: converting information to energy by feedback control

    Full text link
    In 1929, Leo Szilard invented a feedback protocol in which a hypothetical intelligence called Maxwell's demon pumps heat from an isothermal environment and transduces it to work. After an intense controversy that lasted over eighty years; it was finally clarified that the demon's role does not contradict the second law of thermodynamics, implying that we can convert information to free energy in principle. Nevertheless, experimental demonstration of this information-to-energy conversion has been elusive. Here, we demonstrate that a nonequilibrium feedback manipulation of a Brownian particle based on information about its location achieves a Szilard-type information-energy conversion. Under real-time feedback control, the particle climbs up a spiral-stairs-like potential exerted by an electric field and obtains free energy larger than the amount of work performed on it. This enables us to verify the generalized Jarzynski equality, or a new fundamental principle of "information-heat engine" which converts information to energy by feedback control.Comment: manuscript including 7 pages and 4 figures and supplementary material including 6 pages and 8 figure

    Millennial scale persistence of organic carbon bound to iron in Arctic marine sediments

    Get PDF
    Burial of organic material in marine sediments represents a dominant natural mechanism of long-term carbon sequestration globally, but critical aspects of this carbon sink remain unresolved. Investigation of surface sediments led to the proposition that on average 10-20% of sedimentary organic carbon is stabilised and physically protected against microbial degradation through binding to reactive metal (e.g. iron and manganese) oxides. Here we examine the long-term efficiency of this rusty carbon sink by analysing the chemical composition of sediments and pore waters from four locations in the Barents Sea. Our findings show that the carbon-iron coupling persists below the uppermost, oxygenated sediment layer over thousands of years. We further propose that authigenic coprecipitation is not the dominant factor of the carbon-iron bounding in these Arctic shelf sediments and that a substantial fraction of the organic carbon is already bound to reactive iron prior deposition on the seafloor

    Mutation detection by analysis of DNA heteroduplexes in TILLING populations of diploid species

    Get PDF
    In the beginning of mutation research, mutations could only be detected indirectly through the analysis of the phenotypic alterations that they caused. The detection of mutations at the DNA level became possible with the development of sequencing methods. Nowadays, there are many different methods and strategies that have been created for mutation detection, both in natural and mutagenised populations. The strategies differ in accuracy and sensitivity, as well as in the laboratory facilities, time, costs and efforts that are required. The majority of them involve the pooling of DNA samples and the amplification of a gene (fragment) of interest followed by heteroduplex formation. One of the popular strategies for mutation identification takes advantage of the specific endonuclease (e.g. CEL I) that recognises and cuts heteroduplexes precisely at the 3′ position of the mismatch site. The cleaved fragments are usually visualised through electrophoresis in a polyacrylamide gel using LI-COR sequencers, but agarose electrophoresis may also be used for this purpose, although with less sensitivity. A different mutation identification strategy, which is based on the high-resolution melting (HRM) technique, may be the method of choice when working with a short gene or a gene fragment whose length optimally does not exceed 400 bp

    BioPARR:A software system for estimating the rupture potential index for abdominal aortic aneurysms

    Get PDF
    An abdominal aortic aneurysm (AAA) is a permanent and irreversible dilation of the lower region of the aorta. It is a symptomless condition that, if left untreated, can expand until rupture. Despite ongoing efforts, an efficient tool for accurate estimation of AAA rupture risk is still not available. Furthermore, a lack of standardisation across current approaches and specific obstacles within computational workflows limit the translation of existing methods to the clinic. This paper presents BioPARR (Biomechanics based Prediction of Aneurysm Rupture Risk), a software system to facilitate the analysis of AAA using a finite element analysis based approach. Except semi-automatic segmentation of the AAA and intraluminal thrombus (ILT) from medical images, the entire analysis is performed automatically. The system is modular and easily expandable, allows the extraction of information from images of different modalities (e.g. CT and MRI) and the simulation of different modelling scenarios (e.g. with/without thrombus). The software uses contemporary methods that eliminate the need for patient-specific material properties, overcoming perhaps the key limitation to all previous patient-specific analysis methods. The software system is robust, free, and will allow researchers to perform comparative evaluation of AAA using a standardised approach. We report preliminary data from 48 cases

    Disposition of Federally Owned Surpluses

    Get PDF
    PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to experimental challenges with backbone mutations. Here we address this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding. We observe substantial and differential effects upon amide-to-ester mutation in PDZ2 of postsynaptic density protein 95 and other PDZ domains, suggesting that hydrogen bonding at the carboxylate-binding site contributes to both affinity and selectivity. In particular, the hydrogen-bonding pattern is surprisingly different between the non-canonical and canonical interaction. Our data provide a detailed understanding of the role of hydrogen bonds in protein-protein interactions
    • …
    corecore