223 research outputs found
Long-term variability in the diversity of North Sea zooplankton
Results from the Continous Plankton Recorder survey were used to study long-term changes in the zooplankton of four regularly sampled areas of the North Sea. The trends in alpha-diversity are described and analysed. Species associated with inflow of oceanic or mixed waters from the Atlantic or shelf to the west and south of Britain have increased in abundance or frequency of occurence. Meroplankton has also increased, but resident holoplankton and those associated with colder oceanic or mixed waters have declined. These changes have resulted in an increase in the species richness in the areas in the north-western North Sea. There was a period of low diversity in the late 1970s and the early 1980s in the most southerly area, furthest from the sources of inflow. The evidence for a long-term trend was stronger then relationships between diversity and either the North Atlantic Oscillation or variation in position of the Gulf Stream in the western Atlantic
What determines the yen swap spread?
We investigate if Japanese yen denominated interest rate swap spreads price risks in addition to liquidity and default risk. These additional risks include: the time-varying correlation between interest rates of different types and maturities; business cycle risk; and market skewness risk. Our analysis, over a number of different maturities and sample periods, supports the existence of an additional risk premium. We also show that the time-varying correlation between short term market interest rates (e.g., TIBOR) and the longer term Government bond yield (e.g., Gensaki) is of particular importance. Japanese yen swap spreads are shown to contain both pro-cyclical and counter-cyclical elements of business cycle risk, positive risk premia for skewness risk and variable risk premia for correlation risk (between fixed and floating interest rates)
The psychic costs of migration: evidence from Irish return migrants
Within the economics literature, the 'psychic costs' of migration have
been incorporated into theoretical models since Sjaastad (J Polit Econ 70:80
93, 1962). However, the existence of such costs has rarely been investigated
in empirical papers. In this paper, we look at the psychic costs of migration by
using alcohol problems as an indicator. Rather than comparing immigrants and
natives, we look at the native-born in a single country and compare those who
have lived away for a period of their lives and those who have not. We use data
from the first wave of the Irish Longitudinal Study on Ageing which is a large,
nationally representative sample of older Irish adults. We find that men who
lived away are more likely to have suffered from alcohol problems than men
who stayed. For women, we again see a higher incidence of alcohol problems
for short-term migrants. However, long-term female migrants are less likely
to have suffered from alcohol problems. For these women, it seems that
migration provided psychic benefits, and this is consistent with findings fro
Crucial Role for BAFF-BAFF-R Signaling in the Survival and Maintenance of Mature B Cells
Defects in the expression of either BAFF (B cell activating factor) or BAFF-R impairs B cell development beyond the immature, transitional type-1 stage and thus, prevents the formation of follicular and marginal zone B cells, whereas B-1 B cells remain unaffected. The expression of BAFF-R on all mature B cells might suggest a role for BAFF-R signaling also for their in vivo maintenance. Here, we show that, 14 days following a single injection of an anti-BAFF-R mAb that prevents BAFF binding, both follicular and marginal zone B cell numbers are drastically reduced, whereas B-1 cells are not affected. Injection of control, isotype-matched but non-blocking anti-BAFF-R mAbs does not result in B cell depletion. We also show that this depletion is neither due to antibody-dependent cellular cytotoxicity nor to complement-mediated lysis. Moreover, prevention of BAFF binding leads to a decrease in the size of the B cell follicles, an impairment of a T cell dependent humoral immune response and a reduction in the formation of memory B cells. Collectively, these results establish a central role for BAFF-BAFF-R signaling in the in vivo survival and maintenance of both follicular and marginal zone B cell pools
Molecular decoding using luminescence from an entangled porous framework
Chemosensors detect a single target molecule from among several molecules, but cannot differentiate targets from one another. In this study, we report a molecular decoding strategy in which a single host domain accommodates a class of molecules and distinguishes between them with a corresponding readout. We synthesized the decoding host by embedding naphthalenediimide into the scaffold of an entangled porous framework that exhibited structural dynamics due to the dislocation of two chemically non-interconnected frameworks. An intense turn-on emission was observed on incorporation of a class of aromatic compounds, and the resulting luminescent colour was dependent on the chemical substituent of the aromatic guest. This unprecedented chemoresponsive, multicolour luminescence originates from an enhanced naphthalenediimide–aromatic guest interaction because of the induced-fit structural transformation of the entangled framework. We demonstrate that the cooperative structural transition in mesoscopic crystal domains results in a nonlinear sensor response to the guest concentration
BAFF Promotes Th17 Cells and Aggravates Experimental Autoimmune Encephalomyelitis
BAFF, in addition to promoting B cell survival and differentiation, may affect T cells. The objective of this study was to determine the effect of BAFF on Th17 cell generation and its ramifications for the Th17 cell-driven disease, EAE.Th17 cells were increased in BAFF-Tg B6 (B6.BTg) mice and decreased in B6.Baff(-/-) mice. Th17 cells in B6.Baff(-/-) mice bearing a BAFF Tg (B6.Baff(-/-).BTg mice) were identical to those in B6.BTg mice, indicating that membrane BAFF is dispensable for Th17 cell generation as long as soluble BAFF is plentiful. In T + non-T cell criss-cross co-cultures, Th17 cell generation was greatest in cultures containing B6.BTg T cells and lowest in cultures containing B6.Baff(-/-) T cells, regardless of the source of non-T cells. In cultures containing only T cells, Th17 cell generation followed an identical pattern. CD4(+) cell expression of CD126 (IL-6R α chain) was increased in B6.BTg mice and decreased in B6.Baff(-/-) mice, and activation of STAT3 following stimulation with IL-6 + TGF-β was also greatest in B6.BTg cells and lowest in B6.Baff(-/-) cells. EAE was clinically and pathologically most severe in B6.BTg mice and least severe in B6.Baff(-/-) mice and correlated with MOG(35-55) peptide-induced Th17 cell responses.Collectively, these findings document a contribution of BAFF to pathogenic Th17 cell responses and suggest that BAFF antagonism may be efficacious in Th17 cell-driven diseases
Multipotent Capacity of Immortalized Human Bronchial Epithelial Cells
While the adult murine lung utilizes multiple compartmentally restricted progenitor cells during homeostasis and repair, much less is known about the progenitor cells from the human lung. Translating the murine stem cell model to humans is hindered by anatomical differences between species. Here we show that human bronchial epithelial cells (HBECs) display characteristics of multipotent stem cells of the lung. These HBECs express markers indicative of several epithelial types of the adult lung when experimentally tested in cell culture. When cultured in three different three-dimensional (3D) systems, subtle changes in the microenvironment result in unique responses including the ability of HBECs to differentiate into multiple central and peripheral lung cell types. These new findings indicate that the adult human lung contains a multipotent progenitor cell whose differentiation potential is primarily dictated by the microenvironment. The HBEC system is not only important in understanding mechanisms for specific cell lineage differentiation, but also for examining changes that correlate with human lung diseases including lung cancer
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Technical trading and cryptocurrencies
This paper carries out a comprehensive examination of technical trading rules in cryptocurrency markets, using data from two Bitcoin markets and three other popular cryptocurrencies. We employ almost 15,000 technical trading rules from the main five classes of technical trading rules and find significant predictability and profitability for each class of technical trading rule in each cryptocurrency. We find that the breakeven transaction costs are substantially higher than those typically found in cryptocurrency markets. To safeguard against data-snooping, we implement a number of multiple hypothesis procedures which confirms our findings that technical trading rules do offer significant predictive power and profitability to investors. We also show that the technical trading rules offer substantially higher risk-adjusted returns than the simple buy-and-hold strategy, showing protection against lengthy and severe drawdowns associated with cryptocurrency markets. However there is no predictability for Bitcoin in the out-of-sample period, although predictability remains in other cryptocurrency markets
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