1,708 research outputs found
Localization of the murine reduced folate carrier as assessed by immunohistochemical analysis
AbstractThe reduced folate carrier (RFC1) is a major route for the transport of folates in mammalian cells. The localization of RFC1 in murine tissues was evaluated by immunohistochemical analysis using a polyclonal antibody to the C-terminus of the carrier. There was expression of RFC1 in the brush-border membrane of the jejunum, ileum, duodenum and colon. RFC1 was localized to the basolateral membrane of the renal tubular epithelium. Carrier was detected on the plasma membrane of hepatocytes but not in bile duct epithelial cells. In the choroid plexus RFC1 was highly expressed at the apical surface. It was also expressed in axons and dendrites and on the apical membrane of cells lining the spinal canal. In spleen, RFC1 was detected only in the cells of the red pulp. These data provide insights into the role that RFC1 plays in folate delivery in a variety of tissues. In particular, the localization of carrier may elucidate the role of RFC1 in the vectorial transport of folates across epithelia. The data also indicate that in kidney tubules and choroid plexus the sites of RFC1 expression are different from what has been reported previously for the folate receptor; and while RFC1 is expressed in small intestine, folate receptor is not
Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment version 3 data retrievals
Version 3 of the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment data set for some 30 trace and minor gas profiles is available. From the IR solar-absorption spectra measured during four Space Shuttle missions (in 1985, 1992, 1993, and 1994), profiles from more than 350 occultations were retrieved from the upper troposphere to the lower mesosphere. Previous results were unreliable for tropospheric retrievals, but with a new global-fitting algorithm profiles are reliably returned down to altitudes as low as 6.5 km (clouds permitting) and include notably improved retrievals of H2 O, CO, and other species. Results for stratospheric water are more consistent across the ATMOS spectral filters and do not indicate a net consumption of H2 in the upper stratosphere. A new sulfuric-acid aerosol product is described. An overview of ATMOS Version 3 processing is presented with a discussion of estimated uncertainties. Differences between these Version 3 and previously reported Version 2 ATMOS results are discussed. Retrievals are available at http: /atmos.jpl.nasa.gov /atmos
Self-Assembled Charged Hydrogels Control the Alignment of Filamentous Actin
We demonstrate a novel route to control attachment of filamentous actin (F-actin) on hydrogel films. By incorporating an amine-terminated silane, the hydrogel surface charge and surface topography are varied. With increasing silane content, F-actin reorients from perpendicular to parallel to the hydrogel surface, ceases to wobble, and forms mainly elongated or cyclic structures. F-Actin coverage reaches a maximum at 2.5 vol% silane and declines at higher silane content. This biphasic behavior is explained by the simultaneous increase in surface charge and the self-assembly of a micron scale pattern of positively charged islands. Our approach provides guidelines for constructing nanoscale tracks to guide motor proteins underlying nano-engineered devices such as molecular shuttles
There Is No Pure Empirical Reasoning
The justificatory force of empirical reasoning always depends upon the existence of some synthetic, a priori justification. The reasoner must begin with justified, substantive constraints on both the prior probability of the conclusion and certain conditional probabilities; otherwise, all possible degrees of belief in the conclusion are left open given the premises. Such constraints cannot in general be empirically justified, on pain of infinite regress. Nor does subjective Bayesianism offer a way out for the empiricist. Despite often-cited convergence theorems, subjective Bayesians cannot hold that any empirical hypothesis is ever objectively justified in the relevant sense. Rationalism is thus the only alternative to an implausible skepticism
Observations of whistler mode waves with nonlinear parallel electric fields near the dayside magnetic reconnection separatrix by the Magnetospheric Multiscale mission
We show observations from the Magnetospheric Multiscale (MMS) mission of whistler mode waves in the Earth's low-latitude boundary layer (LLBL) during a magnetic reconnection event. The waves propagated obliquely to the magnetic field toward the X line and were confined to the edge of a southward jet in the LLBL. Bipolar parallel electric fields interpreted as electrostatic solitary waves (ESW) are observed intermittently and appear to be in phase with the parallel component of the whistler oscillations. The polarity of the ESWs suggests that if they propagate with the waves, they are electron enhancements as opposed to electron holes. The reduced electron distribution shows a shoulder in the distribution for parallel velocities between 17,000 and 22,000âkm/s, which persisted during the interval when ESWs were observed, and is near the phase velocity of the whistlers. This shoulder can drive Langmuir waves, which were observed in the high-frequency parallel electric field data
Different Wrongs, Different Remedies? Reactions to Organizational Remedies after Procedural and Interactional Injustice
Unemployed, uneducated and sick: the effects of socioeconomic status on health duration in the European Union
This paper employs a logistic model to measure the effect of socioeconomic and individual characteristics on the length of time an individual remains in good health. It employs an objective measure of physical health, the Physical and Mental Health Problems, Illnesses and Disabilities (PMID) measure in the ECHP dataset, for 13 European countries, for the years 1994-2002. The results show that socioeconomic status does affect the likelihood of individuals entering bad health. In particular, unemployment increases and education decreases the probability of a person ceasing to enjoy good health. Income effects, are however, somewhat weaker, being confined to a small number of countries and being mainly observed only for the highest income quartile. Interesting age and gender effects are also found
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A Veritable Menagerie of Heritable Bacteria from Ants, Butterflies, and Beyond: Broad Molecular Surveys and a Systematic Review
Maternally transmitted bacteria have been important players in the evolution of insects and other arthropods, affecting their nutrition, defense, development, and reproduction. Wolbachia are the best studied among these and typically the most prevalent. While several other bacteria have independently evolved a heritable lifestyle, less is known about their host ranges. Moreover, most groups of insects have not had their heritable microflora systematically surveyed across a broad range of their taxonomic diversity. To help remedy these shortcomings we used diagnostic PCR to screen for five groups of heritable symbiontsâArsenophonus spp., Cardinium hertigii, Hamiltonella defensa, Spiroplasma spp., and Wolbachia spp.âacross the ants and lepidopterans (focusing, in the latter case, on two butterfly familiesâthe Lycaenidae and Nymphalidae). We did not detect Cardinium or Hamiltonella in any host. Wolbachia were the most widespread, while Spiroplasma (ants and lepidopterans) and Arsenophonus (ants only) were present at low levels. Co-infections with different Wolbachia strains appeared especially common in ants and less so in lepidopterans. While no additional facultative heritable symbionts were found among ants using universal bacterial primers, microbes related to heritable enteric bacteria were detected in several hosts. In summary, our findings show that Wolbachia are the dominant heritable symbionts of ants and at least some lepidopterans. However, a systematic review of symbiont frequencies across host taxa revealed that this is not always the case across other arthropods. Furthermore, comparisons of symbiont frequencies revealed that the prevalence of Wolbachia and other heritable symbionts varies substantially across lower-level arthropod taxa. We discuss the correlates, potential causes, and implications of these patterns, providing hypotheses on host attributes that may shape the distributions of these influential bacteria.Organismic and Evolutionary Biolog
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