96,489 research outputs found
Intramitochondrial sorting of the precursor to yeast cytochrome c oxidase subunit Va.
We have continued our studies on the import pathway of the precursor to yeast cytochrome c oxidase subunit Va (pVa), a mitochondrial inner membrane protein. Previous work on this precursor demonstrated that import of pVa is unusually efficient, and that inner membrane localization is directed by a membrane-spanning domain in the COOH-terminal third of the protein. Here we report the results of studies aimed at analyzing the intramitochondrial sorting of pVa, as well as the role played by ancillary factors in import and localization of the precursor. We found that pVa was efficiently imported and correctly sorted in mitochondria prepared from yeast strains defective in the function of either mitochondrial heat shock protein (hsp)60 or hsp70. Under identical conditions the import and sorting of another mitochondrial protein, the precursor to the beta subunit of the F1 ATPase, was completely defective. Consistent with previous results demonstrating that the subunit Va precursor is loosely folded, we found that pVa could be efficiently imported into mitochondria after translation in wheat germ extracts. This results suggests that normal levels of extramitochondrial hsp70 are also not required for import of the protein. The results of this study enhance our understanding of the mechanism by which pVa is routed to the mitochondrial inner membrane. They suggest that while the NH2 terminus of pVa is exposed to the matrix and processed by the matrix metalloprotease, the protein remains anchored to the inner membrane before being assembled into a functional holoenzyme complex
Strategies for Parallel Markup
Cross-referenced parallel markup for mathematics allows the combination of
both presentation and content representations while associating the components
of each. Interesting applications are enabled by such an arrangement, such as
interaction with parts of the presentation to manipulate and querying the
corresponding content, and enhanced search indexing. Although the idea of such
markup is hardly new, effective techniques for creating and manipulating it are
more difficult than it appears. Since the structures and tokens in the two
formats often do not correspond one-to-one, decisions and heuristics must be
developed to determine in which way each component refers to and is referred to
by components of the other representation. Conversion between fine and coarse
grained parallel markup complicates ID assignments. In this paper, we will
describe the techniques developed for \LaTeXML, a \TeX/\LaTeX to XML converter,
to create cross-referenced parallel MathML. While we do not yet consider
\LaTeXML's content MathML to be useful, the current effort is a step towards
that continuing goal
Sensory semantic user interfaces (SenSUI)
Rapid evolution of the World Wide Web with its underlying sources of data, knowledge, services and applications continually attempts to support a variety of users, with different backgrounds, requirements and capabilities. In such an environment, it is highly unlikely that a single user interface will prevail and be able to fulfill the requirements of each user adequately. Adaptive user interfaces are able to adapt information and application functionalities to the user context. In contrast, pervasive computing and sensor networks open new opportunities for context aware platforms, one that is able to improve user interface adaptation reacting to environmental and user sensors. Semantic web technologies and ontologies are able to capture sensor data and provide contextual information about the user, their actions, required applications and environment. This paper investigates the viability of an approach where semantic web technologies are used to maximize the efficacy of interface adaptation through the use of available ontology
Factors affecting sorghum protein digestibility
In the semi-arid tropics worldwide, sorghum (Sorghum bicolor (L.) Moench) is cultivated by farmers on a subsistence level and consumed as food by humans. A nutritional limitation to its use is the poor digestibility of sorghum protein when wet cooked. The factors affecting wet cooked sorghum protein digestibility may be categorised into two main groups: exogenous factors (grain organisational structure, polyphenols, phytic acid, starch and non-starch polysaccharides) and endogenous factors (disulphide and non-disulphide crosslinking, kafirin hydrophobicity and changes in protein secondary structure). All these factors have been shown to influence sorghum protein digestibility. More than one factor may be at play at any time depending on the nature or the state in which the sorghum grain is; that is whether whole grain, endosperm, protein body preparation, high-tannin or condensed-tannin-free. It is proposed that protein crosslinking may be the greatest factor that influences sorghum protein digestibility. This may be between ?- and ß-kafirin proteins at the protein body periphery, which may impede digestion of the centrally located major storage protein, a-kafirin, or between ?- or ß-kafirin and a-kafiri
Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones.
Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs
RHESSI Observations of the Solar Flare Iron-line Feature at 6.7 keV
Analysis of RHESSI 3--10 keV spectra for 27 solar flares is reported. This energy range includes thermal free--free and free--bound continuum and two line features, at 6.7keV and 8keV, principally due to highly ionized iron (Fe). We used the continuum and the flux in the so-called Fe-line feature at 6.7keV to derive the electron temperature T_e, the emission measure, and the Fe-line equivalent width as functions of time in each flare. The Fe/H abundance ratio in each flare is derived from the Fe-line equivalent width as a function of T_e. To minimize instrumental problems with high count rates and effects associated with multi-temperature and nonthermal spectral components, spectra are presented mostly during the flare decay phase, when the emission measure and temperature were smoothly varying. We found flare Fe/H abundance ratios that are consistent with the coronal abundance of Fe (i.e. 4 times the photospheric abundance) to within 20% for at least 17 of the 27 flares; for 7 flares, the Fe/H abundance ratio is possibly higher by up to a factor of 2. We find evidence that the Fe XXV ion fractions are less than the theoretically predicted values by up to 60% at T_e=25 MK appear to be displaced from the most recent theoretical values by between 1 and 3 MK
Genomic homogeneity in fibrolamellar carcinomas
Background-Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma (HCC) with distinctive clinical and histological features. To date there have been few studies on the genotypic aspects of FLC and no previous attempts have been made to use the arbitrarily primed-polymerase chain reaction (AF-FCR) technique to detect genetic alterations in this disease.Aim-The aim of this study was to assess the degree of genomic heterogeneity of FEC using the AP-PCR technique. Methods-A fetal of 50 tissue samples of primary and metastatic FLCs from seven patients were microdissected. AP-PCR amplification of each genomic DNA sample was carried out using two arbitrary primers.Results-DNA fingerprints of the primary FLCs and all their metastatic lesions (both synchronous and metachronous disease) were identical in an individual patient. The fingerprints were different between tumours of different patients. No evidence of intratumour heterogeneity was observed.Conclusions-Such genomic homogeneity in FLCs may explain their indolent growth. The absence of clonal evolution, which is present in other tumours (particularly HCCs), may explain the distinct behaviour in this tumour. The tumorigenic pathway and degree of somatic genomic changes in this disease may be less complex than in HCC
Reaching Out ad interim
This archive has the full Sunday Service, bulletin and sermon. See also the following related biblical verses:John 3: 1-17 (http://bible.oremus.org/?ql=356329240)Genesis 12: 1-4a (http://bible.oremus.org/?ql=356329164)Psalm 121 (http://bible.oremus.org/?ql=356329203
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