2,934 research outputs found
Transport of branched tetraether lipids from the Tagus River basin to the coastal ocean of the Portuguese margin: consequences for the interpretation of the MBT’/CBT paleothermometer
Branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are transported from soil to marine sediment by rivers, have been used to reconstruct the mean annual air temperature (MAAT) and soil pH of the drainage basin using the methylation index of branched tetraethers (MBT, recently refined as MBT') and cyclization index of branched tetraethers (CBT) from coastal marine sediment records. In this study we are tracing the brGDGTs from source to sink in the Tagus River basin, the longest river system on the Iberian Peninsula, by determining their concentration and distribution in soils, river suspended particulate matter (SPM), riverbank sediments, marine SPM, and marine surface sediments. The concentrations of brGDGTs in river SPM were substantially higher and their distributions were different compared to those of the drainage basin soils. This indicates that brGDGTs are mainly produced in the river itself. In the marine environment, the brGDGT concentrations rapidly decreased with increasing distance from the Tagus estuary. At the same time, the brGDGT distributions in marine sediments also changed, indicating that marine in-situ production also takes place. These results show that there are various problems that complicate the use of the MBT'/CBT for paleoreconstructions using coastal marine sediments in the vicinity of a river. However, if the majority of brGDGTs are produced in the river, it might be possible to reconstruct the environmental (temperature and pH) conditions of the river water using appropriate aquatic calibrations, provided that marine core locations are chosen in such a way that the brGDGTs in their sediments are predominantly derived from riverine in-situ production
The role of microtubule movement in bidirectional organelle transport
We study the role of microtubule movement in bidirectional organelle
transport in Drosophila S2 cells and show that EGFP-tagged peroxisomes in cells
serve as sensitive probes of motor induced, noisy cytoskeletal motions.
Multiple peroxisomes move in unison over large time windows and show
correlations with microtubule tip positions, indicating rapid microtubule
fluctuations in the longitudinal direction. We report the first high-resolution
measurement of longitudinal microtubule fluctuations performed by tracing such
pairs of co-moving peroxisomes. The resulting picture shows that
motor-dependent longitudinal microtubule oscillations contribute significantly
to cargo movement along microtubules. Thus, contrary to the conventional view,
organelle transport cannot be described solely in terms of cargo movement along
stationary microtubule tracks, but instead includes a strong contribution from
the movement of the tracks.Comment: 24 pages, 5 figure
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Women's views of continuity of information provided during and after pregnancy: A qualitative interview study
Straightforward transfer of care from pregnancy to the postpartum period is associated with health benefits and is desired by women worldwide. Underpinning this transfer of care is the sharing of information between healthcare professionals and the provision of consistent information to women. In this qualitative study, two aspects of continuity of information were examined; first the information passed on from midwife to health visitor regarding a woman and her baby before the health visitor meets the woman postnatally and second, the consistency of information received by women from these two healthcare professionals (the main healthcare providers during and after pregnancy in England). To be eligible for the study, women had to have had a baby in England within 12Â months prior to the interview. Participants also needed to be able to read and speak English and be over 18Â years old. Recruitment of participants was via word of mouth and social media. Twenty-nine mothers were interviewed of whom 19 were first time mothers. The interviews took place in the summer and autumn of 2016 and were transcribed verbatim and analysed using Framework Analysis. Two overarching themes were identified: not feeling listened to and information inconsistencies. Women reported little experience of midwives and health visitors sharing information about their care, forcing women to repeat information. This made women feel not listened to and participants recommended that healthcare professionals share information; prioritising information about labour, mental health, and chronic conditions. Women had mixed experiences regarding receiving information from midwives and health visitors, with examples of both consistent and inconsistent information received. To avoid inconsistent information, joint appointments were recommended. Findings from this study clearly suggest that better communication pathways need to be developed and effectively implemented for midwives and health visitors to improve the care that they provide to women
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