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Economic and social implications of aging societies
The challenge of global population aging has been brought into sharper focus by the financial crisis of 2008. In particular, growing national debt has drawn government attention to two apparently conflicting priorities: the need to sustain public spending on pensions and health care versus the need to reduce budget deficits. A number of countries are consequently reconsidering their pension and health care provisions, which account for up to 40% of all government spending in advanced economies. Yet population aging is a global phenomenon that will continue to affect all regions of the world. By 2050 there will be the same number of old as young in the world, with 2 billion people aged 60 or over and another 2 billion under age 15, each group accounting for 21%of the world’s population.
Journal Article
Star Wars. Feel the force!
\"Discover the amazing power of the Force and the Jedi Knights who can control it!\"--P. [4] of cover.
Book
Adaptive methodology to determine hydrophobicity of nanomaterials in situ
The hydrophobicity of nanoparticles (NPs) is a key property determining environmental fate, biological partitioning and toxicity. However, methods to characterize surface hydrophobicity are not uniformly applied to NPs and cannot quantify surface changes in complex environments. Existing methods designed to evaluate the hydrophobicity of bulk solids, chemicals, and proteins have significant limitations when applied to NPs. In this study, we modified and evaluated two methods to determine the hydrophobicity of NPs, hydrophobic interaction chromatography (HIC) and dye adsorption, and compared them to the standard octanol-water partitioning protocol for chemicals. Gold, copper oxide, silica, and amine-functionalized silica NPs were used to evaluate methods based on their applicability to NPs that agglomerate and have surface coatings. The octanol water partitioning and HIC methods both measured Au NPs as hydrophilic, but despite having a small size and stable suspension, NPs could not be fully recovered from the HIC column. For the dye adsorption method, hydrophobic (Rose Bengal) and hydrophilic (Nile Blue) dyes were adsorbed to the NP surface, and linear isotherm parameters were used as a metric for hydrophobicity. CuO was determined to be slightly hydrophilic, while SiO.sub.2 was hydrophilic and Ami-SiO.sub.2 was hydrophobic. The advantages and limitations of each method are discussed, and the dye adsorption method is recommended as the most suitable for application across broad classes of nanomaterials. The dye assay method was further used to measure changes in the surface hydrophobicity of TiO.sub.2 NPs after being suspended in natural water collected from the Alsea Rivers watershed in Oregon. TiO.sub.2 NPs adsorbed Rose Bengal when suspended in ultrapure water, but adsorbed Nile Blue after being incubated in natural water samples, demonstrating a shift from hydrophobic to hydrophilic properties on the outer surface. The dye adsorption method can be applied to characterize surface hydrophobicity of NPs and quantify environmental transformations, potentially improving environmental fate models.
Journal Article
Inside creative writing : interviews with contemporary writers
\"High profile writers, including Philip Pullman, Nadine Gordimer, Kate Grenville and Robert Pinsky, talk about their writing practice and ways of working. Designed with the needs of creative writers in mind, Graeme Harper explores both practice and process, asking authors questions about subjects ranging from motivation to creativity to drafting. \"-- Provided by publisher.
Book
Systematic analysis of ribophagy in human cells reveals bystander flux during selective autophagy
Ribosomes are abundant cellular machines
1
,
2
that are regulated by assembly, supernumerary subunit turnover and nascent chain quality control mechanisms
1
–
5
. Moreover, nitrogen starvation in yeast has been reported to promote selective ribosome delivery to the vacuole in an autophagy conjugation system dependent manner, a process called ‘ribophagy’
6
,
7
. However, whether ribophagy in mammals is selective or regulated is unclear. Using Ribo–Keima flux reporters, we find that starvation or mTOR inhibition promotes VPS34-dependent ribophagic flux, which, unlike yeast, is largely independent of ATG8 conjugation and occurs concomitantly with other cytosolic protein autophagic flux reporters
8
,
9
. Ribophagic flux was not induced upon inhibition of translational elongation or nascent chain uncoupling, but was induced in a comparatively selective manner under proteotoxic stress induced by arsenite
10
or chromosome mis-segregation
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, dependent upon VPS34 and ATG8 conjugation. Unexpectedly, agents typically used to induce selective autophagy also promoted increased ribosome and cytosolic protein reporter flux, suggesting significant bulk or ‘bystander’ autophagy during what is often considered selective autophagy
12
,
13
. These results emphasize the importance of monitoring non-specific cargo flux when assessing selective autophagy pathways.
An and Harper quantify ribophagy in mammalian cells and show that nutrient-deprivation-induced ribophagy is independent of the ATG8 conjugation system, whereas proteotoxic stress-induced ribophagy requires ATG5 and VPS34.
Journal Article
What is citizenship?
Readers explore what citizenship is, as well as what it means to be a good citizen who embraces the duties and advantages that status entails.
Book
Comparative toxicological assessment of PAMAM and thiophosphoryl dendrimers using embryonic zebrafish
Dendrimers are well-defined, polymeric nanomaterials currently being investigated for biomedical applications such as medical imaging, gene therapy, and tissue targeted therapy. Initially, higher generation (size) dendrimers were of interest because of their drug carrying capacity. However, increased generation was associated with increased toxicity. The majority of studies exploring dendrimer toxicity have focused on a small range of materials using cell culture methods, with few studies investigating the toxicity across a wide range of materials in vivo. The objective of the present study was to investigate the role of surface charge and generation in dendrimer toxicity using embryonic zebrafish (Danio rerio) as a model vertebrate. Due to the generational and charge effects observed at the cellular level, higher generation cationic dendrimers were hypothesized to be more toxic than lower generation anionic or neutral dendrimers with the same core composition. Polyamidoamine (PAMAM) dendrimers elicited significant morbidity and mortality as generation was decreased. No significant adverse effects were observed from the suite of thiophosphoryl dendrimers studied. Exposure to ≥50 ppm cationic PAMAM dendrimers G3-amine, G4-amine, G5-amine, and G6-amine caused 100% mortality by 24 hours post-fertilization. Cationic PAMAM G6-amine at 250 ppm was found to be statistically more toxic than both neutral PAMAM G6-amidoethanol and anionic PAMAM G6-succinamic acid at the same concentration. The toxicity observed within the suite of varying dendrimers provides evidence that surface charge may be the best indicator of dendrimer toxicity. Dendrimer class and generation are other potential contributors to the toxicity of dendrimers. Further studies are required to better understand the relative role each plays in driving the toxicity of dendrimers. To the best of our knowledge, this is the first in vivo study to address such a broad range of dendrimers.
Journal Article
Miss Mingo and the first day of school
Miss Mingo helps all of the animal students in her class overcome their shyness on the first day of school by encouraging them to share something special about themselves. Includes facts about animals.
Book
Increasing water-use efficiency directly through genetic manipulation of stomatal density
Improvement in crop water-use efficiency (WUE) is a critical priority for regions facing increased drought or diminished groundwater resources. Despite new tools for the manipulation of stomatal development, the engineering of plants with high WUE remains a challenge.
We used Arabidopsis epidermal patterning factor (EPF) mutants exhibiting altered stomatal density to test whether WUE could be improved directly by manipulation of the genes controlling stomatal density. Specifically, we tested whether constitutive overexpression of EPF2 reduced stomatal density and maximum stomatal conductance (g
w(max)) sufficiently to increase WUE.
We found that a reduction in g
w(max) via reduced stomatal density in EPF2-overexpressing plants (EPF2OE) increased both instantaneous and long-term WUE without altering significantly the photosynthetic capacity. Conversely, plants lacking both EPF1 and EPF2 expression (epf1epf2) exhibited higher stomatal density, higher g
w(max) and lower instantaneous WUE, as well as lower (but not significantly so) long-term WUE.
Targeted genetic modification of stomatal conductance, such as in EPF2OE, is a viable approach for the engineering of higher WUE in crops, particularly in future high-carbon-dioxide (CO2) atmospheres.
Journal Article