213 research outputs found

    Uncovering the Global Life Cycles of the Rare Earth Elements

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    The rare earth elements (REE) are a group of fifteen elements with unique properties that make them indispensable for a wide variety of emerging, critical technologies. Knowledge of the life cycles of REE remains sparse, despite the current heightened interest in their future availability. Mining is heavily concentrated in China, whose monopoly position and potential restriction of exports render primary supplies vulnerable to short and long-term disruption. To provide an improved perspective we derived the first quantitative life cycles (for the year 2007) for ten REE: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), and yttrium (Y). Of these REE, Ce and Nd in-use stocks are highest; the in-use stocks of most REE show significant accumulation in modern society. Industrial scrap recycling occurs only from magnet manufacture. We believe there is no post-customer recycling of any of these elements

    Capacity and Procedural Accounts of Impaired Memory in Depression

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    Findings of impaired memory in states of dysphoria or depression are summarized and subsumed under different accounts of mood-related memory deficits. Theoretical accounts based on the assumption of a storage system of limited capacity are compared to accounts which emphasize the role of procedures and strategies in attending and remembering. Two reanalyses of a recent experiment in the process-dissociation paradigm are reported. They address issues of dysphoria-related differences in automatic versus controlled uses of memory in a task of word-stem completion. The two reanalyses rest on different assumptions about the relation between automatic and controlled components, but they converge in highlighting the advantages of a procedural rather than capacity-based view of memory deficits. finally. similarities to other research domains and theoretical approaches are outlined

    Genetic and Epigenetic Alterations of the NF2 Gene in Sporadic Vestibular Schwannomas

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    BACKGROUND: Mutations in the neurofibromatosis type 2 (NF2) tumor-suppressor gene have been identified in not only NF2-related tumors but also sporadic vestibular schwannomas (VS). This study investigated the genetic and epigenetic alterations in tumors and blood from 30 Korean patients with sporadic VS and correlated these alterations with tumor behavior. METHODOLOGY/PRINCIPAL FINDINGS: NF2 gene mutations were detected using PCR and direct DNA sequencing and three highly polymorphic microsatellite DNA markers were used to assess the loss of heterozygosity (LOH) from chromosome 22. Aberrant hypermethylation of the CpG island of the NF2 gene was also analyzed. The tumor size, the clinical growth index, and the proliferative activity assessed using the Ki-67 labeling index were evaluated. We found 18 mutations in 16 cases of 30 schwannomas (53%). The mutations included eight frameshift mutations, seven nonsense mutations, one in-frame deletion, one splicing donor site, and one missense mutation. Nine patients (30%) showed allelic loss. No patient had aberrant hypermethylation of the NF2 gene and correlation between NF2 genetic alterations and tumor behavior was not observed in this study. CONCLUSIONS/SIGNIFICANCE: The molecular genetic changes in sporadic VS identified here included mutations and allelic loss, but no aberrant hypermethylation of the NF2 gene was detected. In addition, no clear genotype/phenotype correlation was identified. Therefore, it is likely that other factors contribute to tumor formation and growth

    Spared unconscious influences of spatial memory in diencephalic amnesia

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    Spatial memory is crucial to our daily lives and in part strongly depends on automatic, implicit memory processes. This study investigates the neurocognitive basis of conscious and unconscious influences of object–location memory in amnesic patients with Korsakoff’s syndrome (N = 23) and healthy controls (N = 18) using a process-dissociation procedure in a computerized spatial memory task. As expected, the patients performed substantially worse on the conscious memory measures but showed even slightly stronger effects of unconscious influences than the controls. Moreover, a delayed test administered after 1 week revealed a strong decline in conscious influences in the patients, while unconscious influences were not affected. The presented results suggest that conscious and unconscious influences of spatial memory can be clearly dissociated in Korsakoff’s syndrome

    The role of glucocorticoids in the induction of zinc-α2-glycoprotein expression in adipose tissue in cancer cachexia

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    Loss of adipose tissue in cancer cachexia in mice bearing the MAC16 tumour arises from an increased lipid mobilisation through increased expression of zinc-α2-glycoprotein (ZAG) in white (WAT) and brown (BAT) adipose tissue. Glucocorticoids have been suggested to increase ZAG expression, and this study examines their role in cachexia and the mechanisms involved. In mice bearing the MAC16 tumour, serum cortisol concentrations increased in parallel with weight loss, and the glucocorticoid receptor antagonist RU38486 (25 mg kg−1) attenuated both the loss of body weight and ZAG expression in WAT. Dexamethasone (66 μg kg−1) administration to normal mice produced a six-fold increase in ZAG expression in both WAT and BAT, which was also attenuated by RU38486. In vitro studies using 3T3-L1 adipocytes showed dexamethasone (1.68 μM) to stimulate lipolysis and increase ZAG expression, and both were attenuated by RU38486 (10 μM), anti-ZAG antibody (1 μgml−1), and the β3-adrenoreceptor (β3-AR) antagonist SR59230A (10 μM). Zinc-α2-glycoprotein also increased its own expression and this was attenuated by SR59230A, suggesting that it was mediated through the β3-AR. This suggests that glucocorticoids stimulate lipolysis through an increase in ZAG expression, and that they are responsible for the increase in ZAG expression seen in adipose tissue of cachectic mice

    Consumer perceptions of co-branding alliances: Organizational dissimilarity signals and brand fit

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    This study explores how consumers evaluate co-branding alliances between dissimilar partner firms. Customers are well aware that different firms are behind a co-branded product and observe the partner firms’ characteristics. Drawing on signaling theory, we assert that consumers use organizational characteristics as signals in their assessment of brand fit and for their purchasing decisions. Some organizational signals are beyond the control of the co-branding partners or at least they cannot alter them on short notice. We use a quasi-experimental design and test how co-branding partner dissimilarity affects brand fit perception. The results show that co-branding partner dissimilarity in terms of firm size, industry scope, and country-of-origin image negatively affects brand fit perception. Firm age dissimilarity does not exert significant influence. Because brand fit generally fosters a benevolent consumer attitude towards a co-branding alliance, the findings suggest that high partner dissimilarity may reduce overall co-branding alliance performance

    Ideological Labels in America

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    This paper extends Ellis and Stimson’s (Ideology in America. New York: Cambridge UniversityPress, 2012) study of the operational-symbolic paradox using issue-level measures of ideological incongruence based on respondent positions and symbolic labels for these positions across 14 issues. Like Ellis and Stimson, we find that substantial numbers—over 30 %—of Americans experience conflicted conservatism. Our issue-level data reveal, furthermore, that conflicted conservatism is most common on the issues of education and welfare spending. In addition, we also find that 20 % of Americans exhibit conflicted liberalism. We then replicate Ellis and Stimson’s finding that conflicted conservatism is associated with low sophistication and religiosity, but also find that it is associated with being socialized in a post-1960s generation and using Fox News as a main news source. Finally, we show the important role played by identities, with both conflicted conservatism and conflicted liberalism linked with partisan and ideological identities, and conflicted liberalism additionally associated with ethnic identities

    Activation of the SPHK/S1P signalling pathway is coupled to muscarinic receptor-dependent regulation of peripheral airways

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    BACKGROUND: In peripheral airways, acetylcholine induces contraction via activation of muscarinic M2-and M3-receptor subtypes (M(2)R and M(3)R). Cholinergic hypersensitivity is associated with chronic obstructive pulmonary disease and asthma, and therefore the identification of muscarinic signaling pathways are of great therapeutic interest. A pathway that has been shown to be activated via MR and to increase [Ca(2+)](i )includes the activation of sphingosine kinases (SPHK) and the generation of the bioactive sphingolipid sphingosine 1-phosphate (S1P). Whether the SPHK/S1P signaling pathway is integrated in the muscarinic control of peripheral airways is not known. METHODS: To address this issue, we studied precision cut lung slices derived from FVB and M(2)R-KO and M(3)R-KO mice. RESULTS: In peripheral airways of FVB, wild-type, and MR-deficient mice, SPHK1 was mainly localized to smooth muscle. Muscarine induced a constriction in all investigated mouse strains which was reduced by inhibition of SPHK using D, L-threo-dihydrosphingosine (DHS) and N, N-dimethyl-sphingosine (DMS) but not by N-acetylsphingosine (N-AcS), a structurally related agent that does not affect SPHK function. The initial phase of constriction was nearly absent in peripheral airways of M(3)R-KO mice when SPHK was inhibited by DHS and DMS but was unaffected in M(2)R-KO mice. Quantitative RT-PCR revealed that the disruption of the M(2)R and M(3)R genes had no significant effect on the expression levels of the SPHK1-isoform in peripheral airways. CONCLUSION: These results demonstrate that the SPHK/S1P signaling pathway contributes to cholinergic constriction of murine peripheral airways. In addition, our data strongly suggest that SPHK is activated via the M(2)R. Given the important role of muscarinic mechanisms in pulmonary disease, these findings should be of considerable therapeutic relevance

    Overexpression of Nrdp1 in the Heart Exacerbates Doxorubicin-Induced Cardiac Dysfunction in Mice

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    BACKGROUND: Cardiac cell death and generation of oxidative stress contribute to doxorubicin (DOX)-induced cardiac dysfunction. E3 ligase Nrdp1 plays a critical role in the regulation of cell apoptosis, inflammation and production of reactive oxygen species (ROS), which may contribute to heart failure. However, the role of Nrdp1 in DOX-induced cardiac injury remains to be determined. METHODS AND RESULTS: We examined the effect of Nrdp1 overexpression with DOX treatment in rat neonatal cardiomyocytes and mouse heart tissue. Cardiomyocytes were infected with adenovirus containing GFP (Ad-GFP), Nrdp1 wild-type (Ad-Nrdp1) or the dominant-negative form of Nrdp1 (Ad-Dn-Nrdp1), then treated with DOX for 24 hr. DOX treatment increased cell death and apoptosis, with Ad-Nrdp1 infection enhancing these actions but Ad-Dn-Nrdp1 infection attenuating these effects. Furthermore, 5 days after a single injection of DOX (20 mg/kg, intraperitoneally), Nrdp1 transgenic mice (TG) showed decreased cardiac function and increased apoptosis, autophagy and oxidative stress as compared with wild-type (WT) mice (P<0.01). Survival rate was significantly lower in Nrdp1 TG mice than in WT mice 10 days after DOX injection (P<0.01). CONCLUSIONS/SIGNIFICANCE: These results were associated with decreased activation of Akt, extracellular signal-regulated kinase 1/2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3) signaling pathways. Nrdp1 may be a key mediator in the development of cardiac dysfunction after DOX treatment and associated with inhibition of Akt, ERK1/2 and STAT3. Nrdp1 may be a new therapeutic target in protecting against the cardiotoxic effects of DOX
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