70 research outputs found
Developmental plasticity of the stress response in female but not in male guppies
To survive, animals must respond appropriately to stress. Stress responses are costly, so early-life experiences with potential stressors could adaptively tailor adult stress responses to local conditions. However, how multiple stressors influence the development of the stress response remains unclear, as is the role of sex. Trinidadian guppies (Poecilia reticulata) are small fish with extensive life-history differences between the sexes and population variation in predation pressure and social density. We investigated how sex and early-life experience influence hormonal stress responses by manipulating conspecific density and perceived predation risk during development. In adults, we sampled cortisol twice to measure initial release and change over time in response to a recurring stressor. The sexes differed considerably in their physiological stress response. Males released more cortisol for their body mass than females and did not reduce cortisol release over time. By contrast, all females, except those reared at high density together with predation cues, reduced cortisol release over time. Cortisol responses of males were thus less dynamic in response to current circumstances and early-life experiences than females, consistent with life-history differences between the sexes. Our study underscores the importance of early-life experiences, interacting ecological factors and sex differences in the organization of the stress response
A new hammer to crack an old nut : interspecific competitive resource capture by plants is regulated by nutrient supply, not climate
Peer reviewedPublisher PD
Aldose Reductase Inhibition Prevents Metaplasia of Airway Epithelial Cells
BACKGROUND: Goblet cell metaplasia that causes mucus hypersecretion and obstruction in the airway lumen could be life threatening in asthma and chronic obstructive pulmonary disease patients. Inflammatory cytokines such as IL-13 mediate the transformation of airway ciliary epithelial cells to mucin-secreting goblet cells in acute as well as chronic airway inflammatory diseases. However, no effective and specific pharmacologic treatment is currently available. Here, we investigated the mechanisms by which aldose reductase (AR) regulates the mucus cell metaplasia in vitro and in vivo. METHODOLOGY/FINDINGS: Metaplasia in primary human small airway epithelial cells (SAEC) was induced by a Th2 cytokine, IL-13, without or with AR inhibitor, fidarestat. After 48 h of incubation with IL-13 a large number of SAEC were transformed into goblet cells as determined by periodic acid-schiff (PAS)-staining and immunohistochemistry using antibodies against Mucin5AC. Further, IL-13 significantly increased the expression of Mucin5AC at mRNA and protein levels. These changes were significantly prevented by treatment of the SAEC with AR inhibitor. AR inhibition also decreased IL-13-induced expression of Muc5AC, Muc5B, and SPDEF, and phosphorylation of JAK-1, ERK1/2 and STAT-6. In a mouse model of ragweed pollen extract (RWE)-induced allergic asthma treatment with fidarestat prevented the expression of IL-13, phosphorylation of STAT-6 and transformation of epithelial cells to goblet cells in the lung. Additionally, while the AR-null mice were resistant, wild-type mice showed goblet cell metaplasia after challenge with RWE. CONCLUSIONS: The results show that exposure of SAEC to IL-13 caused goblet cell metaplasia, which was significantly prevented by AR inhibition. Administration of fidarestat to mice prevented RWE-induced goblet cell metaplasia and AR null mice were largely resistant to allergen induced changes in the lung. Thus our results indicate that AR inhibitors such as fidarestat could be developed as therapeutic agents to prevent goblet cell metaplasia in asthma and related pathologies
To Each According to His Need? Variability in the Responses to Inequity in Nonhuman Primates
While it is well established that humans respond to inequity, it remains unclear the extent to which this behavior occurs in our nonhuman primate relatives. By comparing a variety of species, spanning from New World and Old World monkeys to great apes, scientists can begin to answer questions about how the response to inequity evolved, what the function of this response is, and why and how different contexts shape it. In particular, research across nonhuman primate species suggests that the response is quite variable across species, contexts and individuals. In this paper, we aim to review these differences in an attempt to identify and better understand the patterns that emerge from the existing data with the goal of developing directions for future research. To begin, we address the importance of considering socio-ecological factors in nonhuman primates in order to better understand and predict expected patterns of cooperation and aversion to inequity in different species, following which we provide a detailed analysis of the patterns uncovered by these comparisons. Ultimately, we use this synthesis to propose new ideas for research to better understand this response and, hence, the evolution of our own responses to inequity
On the typology and the worship status of sacred trees with a special reference to the Middle East
This article contains the reasons for the establishment of sacred trees in Israel based on a field study. It includes 97 interviews with Muslim and Druze informants. While Muslims (Arabs and Bedouins) consider sacred trees especially as an abode of righteous figures' (Wellis') souls or as having a connection to their graves, the Druze relate sacred trees especially to the events or deeds in the lives of prophets and religious leaders. A literary review shows the existence of 24 known reasons for the establishment of sacred trees worldwide, 11 of which are known in Israel one of these is reported here for the first time. We found different trends in monotheistic and polytheistic religions concerning their current worship of sacred trees
Revival of the Magnetar PSR J1622–4950: Observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
© 2018. The American Astronomical Society.. New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100 larger than during its dormant state. The X-ray flux one month after reactivation was at least 800 larger than during quiescence, and has been decaying exponentially on a 111 19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation
To Each According to his Need? Variability in the Responses to Inequity in Non-Human Primates
Developing the ReAl Time Transient AnalYser 2 (RATTY2)
IngenieursweseElektriese En Elektroniese IngeniePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]
A Time-Domain Nested-Enclosure Technique for Shielding Effectiveness Characterization
Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.IngenieursweseElektriese En Elektroniese Ingeni
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