6,373 research outputs found

    Northeastern Atlantic benthic foraminifera during the last 45,000 years: Changes in productivity seen from the bottom up

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    We studied benthic foraminifera from the last 45 kyr in the >63 mu m size fraction in Biogeochemical Ocean Flux Studies (BOFS) cores 5K (50 degrees 41.3'N, 21 degrees 51.9'W, depth 3547 m) and 14K (58 degrees 37.2'N, 19 degrees 26.2'W, depth 1756 m), at a time resolution of several hundreds to a thousand years. The deepest site showed the largest fluctuations in faunal composition, species richness, and benthic foraminiferal accumulation rates; the fluctuations resulted from changes in abundance of Epistominella exigua and Alabaminella weddellensis. In the present oceans, these species bloom opportunistically when a spring plankton bloom results in seasonal deposition of phytodetritus on the seafloor. The ''phytodetritus species'' had very low relative abundances and accumulation rates during the last glacial maximum. A strong increase in absolute and relative abundance of E. exigua and A weddellensis during deglaciation paralleled the decrease in abundance of the polar planktonic foraminifer Neogloboquadrina pachyderma (s), and the increase in abundance of warmer water planktonic species such as Globigerina bulloides. This strong increase in relative abundance of the ''phytodetritus species'' and the coeval increase in benthic foraminiferal accumulation rate were thus probably caused by an increase in the deposition of phytodetritus to the seafloor (and thus probably of surface productivity) when the polar front retreated to higher latitudes. The abundance of ''phytodetritus species'' decreased during the Younger Dryas, but not to the low levels of fully glacial conditions. During Heinrich events (periods of excessive melt-water formation and ice rafting) benthic accumulation rates were very low, as were the absolute and relative abundances of the ''phytodetritus species'', supporting suggestions that surface productivity was very low during these events. In both cores Pullenia and Cassidulina species were common during isotope stages 2, 3 and 4, as were bolivinid, buliminid and uvigerinid species. High relative abundances of these species have been interpreted as indicative either of sluggish deep water circulation or of high organic carbon fluxes to the seafloor. In our cores, relative abundances of these species are negatively correlated with benthic foraminiferal accumulation rates, and we can thus not interpret them as indicative of increased productivity during glacials. The percentage of these ''low oxygen'' species calculated on a ''phytodetritus species'' - free basis decreased slightly at deglaciation at 5K, but not at 14K. This suggests that decreased production of North Atlantic Deep Water during the last glacial might have slightly affected benthic foraminiferal faunas in the eastern North Atlantic at 3547 m depth, but not at 1756 m. In conclusion, major changes in deep-sea benthic foraminiferal faunas over the last 45,000 years in our cores from the northeastern Atlantic were the result of changes in surface water productivity, not of changes in deep water circulation; productivity was lower during the glacial, probably because of extensive ice cover

    Modernity, crafts and guilded practices: locating the historical geographies of 20th century craft organisations

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    This is the author accepted manuscript. The final version is available from Routledge via the ISBN in this recordArts and Humanities Research Council (AHRC)Arts and Humanities Research Council (AHRC

    Preliminary investigation of the influence of long-term dietary isoflavone intake on puberty onset and oestrous cycles in domestic cats (Felis catus)

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    Genistein and daidzein are isoflavones which are reported to influence the reproductive system in a variety of mammalian species. This pilot study aimed to determine if dietary isoflavones could potentially influence reproductive parameters in domestic cats, when consumed during the postnatal development period. Cats (n=12) were maintained on either a treatment (150µg/g DM genistein and 150µg/g DM daidzein, n=4) or control (isoflavone free, n= 8) diet from weaning, up to 414 (±17.2) days post-weaning. Vaginal smears were taken thrice weekly and examined for oestrogen-induced cellular degradation in all cats. Behavioural indicators of oestrous were routinely scored for the presence or absence of six key behaviours. Genistein and daidzein did not alter puberty onset or oestrous cycle parameters in these cats (P>0.05). Behavioural scores were higher in cats in the treatment group than control. Incidence of apparent spontaneous ovulation (inferred from extended inter-oestrous periods) was greater in treated cats than control cats, although serum hormone profiles were not available to confirm this observation. Further testing is warranted

    Preliminary investigation of the effects of long-term dietary intake of genistein and daidzein on hepatic histopathology and biochemistry in domestic cats (Felis catus)

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    Dietary isoflavones have been hypothesised to play a role in hepatic veno-occlusive disease in captive exotic felids, although empirical evidence is lacking. This study aimed to investigate the effect of long-term (>1 year) dietary genistein and daidzein exposure on the hepatic biochemistry and histology of domestic cats. Individual cats were assessed for hepatic enzyme and bile acid production before and after the removal of isoflavones from their diet in the treatment group (n=4), and at the same times in unexposed control animals (n=7). No significant differences were detectable in hepatic biochemistry between treatment and control groups, and all serum values were within the normal reference ranges for domestic cats. Additionally, treatment animals demonstrated slightly greater areas of fibrosis surrounding hepatic venules than control animals, but this difference was not statistically significant. On the basis of the results presented, dietary isoflavones, at the current dose and duration of exposure do not appear to modulate hepatic enzyme production or histological parameters

    Preliminary investigation of the influence of long-term dietary isoflavone intake on reproductive tract histology and sex steroid receptor expression in female domestic cats (Felis catus)

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    Genistein and daidzein are isoflavones which are reported to influence the reproductive system in a variety of mammalian species. This pilot study aimed to determine if dietary isoflavones could potentially influence reproductive tract histology or morphology in domestic cats, when consumed during the postnatal development period. Cats were maintained on either treatment (150 µg/g DM genistein and 150 µg/g DM daidzein, n=4) or control (isoflavone free, n=8) diets from weaning, up to 414 (±17.2) days post-weaning. Reproductive tissues were collected during routine ovario-hysterectomy and examined for histology and sex steroid receptor expression. Findings indicate that these dietary isoflavones influenced the expression of oestrogen receptor α (ERα) and oestrogen receptor β (ERβ), and progesterone receptor in feline reproductive tissues. One cat in the treatment group developed suppurative endometritis, but no evidence of uterotrophic or histological changes were found in any other cats. The potential to alter expression of hormone receptors in the reproductive tract of domestic cats exposed to genistein and daidzein warrants further investigation

    Making livelihoods within communities of practice: The place of guild organisations in the craft sector

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    This is the author accepted manuscript. The final version is available from Routledge via the ISBN in this recordThis chapter interrogates the place of professional networks as communities of practice for craft practitioners who live in remote, rural locations and make their livelihood from their creative practice. The South West region of Britain, has a significant population of craft makers working in a highly distributed manner. Some makers work in small clusters (Harvey et al. 2012) but many work in their own homes or individual workshops. Through in depth qualitative analysis, it locates the ways in which makers develop or join organisations to support their livelihoods, particularly those that distinguish the quality and value of the skilled labour that makes hand-crafted work. Specifically, it explores the role of regional craft guilds for their members, and what members value about these organisations.Arts and Humanities Research Council (AHRC

    Supporting Conservation: The Roles of Flagship Species and Identifiable Victims

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    Psychological insights into human behaviour can have enormous applied value for promoting charitable giving. Nevertheless, the application of these insights to conservation appeals featuring non-human animals has scarcely been explored. Although people often donate more when presented with single 'identifiable' victims, whether this effect also extends to non-humans is not known. Similarly, although many conservation appeals feature flagship species, it is unclear whether flagship species generate increased donations. We experimentally investigated how (i) identifiable versus statistical beneficiaries and (ii) flagship versus non-flagship species affected donations to a conservation charity. Unexpectedly, subjects did not donate more when presented with single identifiable beneficiaries rather than groups of beneficiaries. Flagship species, on the other hand, increased donation amounts relative to appeals featuring non-flagship species. We discuss how these findings can inform and improve the effectiveness of conservation fundraising appeals

    Characteristics of ex-racing greyhounds in New Zealand and their impact on re-homing

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    A small proportion of greyhounds surplus to the racing industry are entered into specialist rehoming organisations to be re-purposed as pets. Records of 835 greyhounds, from New Zealand Greyhounds as Pets (GAP), were used to investigate whether pre-adoption characteristics (age, sex, racing record, reason entered) and management factors (temperament test result, foster and trainer effects) had a bearing on rehoming success, and comparisons were made with shelter studies. Rehoming greyhounds as pets is very successful with 85.5% ultimately successfully rehomed. Only 2.9% fail as a result of failed adoptions, 11.6% fail the initial temperament test. Greyhounds were more likely than shelter dogs to pass an initial temperament test and be adopted, and less likely to be returned after 1 month. However, adopted greyhounds were just as likely as shelter dogs to be returned after 6 months. Logistic regression revealed the youngest age group (< 24 months old) were more likely to pass the initial temperament test than older greyhounds. This age effect was not detectable when the adoption success of dogs subsequently available for rehoming was considered, but a sex effect was evident with females more likely to be successfully adopted than males. Whether or not a dog had raced had no significant effect on the likelihood of successful rehoming. Greyhounds passing the temperament test with a basic pass, were less likely to be successfully rehomed than greyhounds scoring a higher pass indicative of lower prey drive. Further investigation of the validity and reliablity of the temperament test is warranted

    Do delays in data availability limit the implementation of near real-time vaccine safety surveillance using the Clinical Practice Research Datalink?

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    Near real-time vaccine safety surveillance (NRTVSS) using electronic health records has been used to detect timely vaccine safety signals. Trial implementation of NRTVSS using the Clinical Practice Research Datalink (CPRD) has shown that there is limited power to detect safety signals for rare events. Delays in recording outcomes and receiving data influence the power and timeliness to identify a signal. Our work aimed to compare how different sources of delays influence power and expected time to signal to implement NRTVSS using CPRD. We studied seasonal influenza vaccine/Guillain-Barré syndrome and performed power and expected time to signal calculations for the 2013-2014/2014-2015 seasons. We used the Poisson-based maximised sequential probability ratio test, which compares observed-to-expected events. For each study season, we obtained an average Guillain-Barré syndrome/seizures age-sex-adjusted rate from the 5 previous seasons and then used this rate to calculate the expected number of events, assuming a 42-day risk-window. Calculations were performed for detecting rate ratios of 1.5 to 10. We compared power and timeliness considering combinations of the presence/absence of delays in recording outcomes and in receiving data. The R-package Sequential was used. In general, there was ≥80% power to detect increases in risk of ≥4 at the end of the season. Assuming absence of delays slightly improved power (a maximum increase of 4%) but did not noticeably reduce time to detect a signal. Removing delays in data availability is insufficient to significantly improve the performance of a NRTVSS system using CPRD. Expansion of CPRD data is required. KEY POINTS The Clinical Practice Research Datalink (CPRD) can be used to implement near real-time vaccine safety surveillance, but there is limited power to detect signals for rare outcomes. Delays in recording outcomes and in receiving data might limit power and timeliness of a system. We assessed the influence of these sources of delays to inform data providers of the steps required to improve a system using CPRD data. Removing delays in recording outcomes and receiving data is unlikely to significantly improve the performance of a system using CPRD data. Expansion of the data available is needed

    The human myometrium differentially expresses mTOR signalling components before and during pregnancy: Evidence for regulation by progesterone

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    Emerging studies implicate the signalling of the mammalian target of rapamycin (mTOR) in a number of reproductive functions. To this date, there are no data regarding the expression of mTOR signalling components in the human myometrium during pregnancy. We hypothesized that mTOR-related genes might be differentially expressed in term or preterm labour as well as in labour or non-labour myometria during pregnancy. Using quantitative RT-PCR we demonstrate for first time that there is a significant downregulation of mTOR, DEPTOR, and Raptor in preterm labouring myometria when compared to non-pregnant tissues taken from the same area (lower segment). We used an immortalized myometrial cell line (ULTR) as an in vitro model to dissect further mTOR signalling. In ULTR cells DEPTOR and Rictor had a cytoplasmic distribution, whereas mTOR and Raptor were detected in the cytoplasm and the nucleus, indicative of mTORC1 shuttling. Treatment with inflammatory cytokines caused only minor changes in gene expression of these components, whereas progesterone caused significant down-regulation. We performed a non-biased gene expression analysis of ULTR cells using Nimblegen human gene expression microarray (n = 3), and selected genes were validated by quantitative RT-PCR in progesterone treated myometrial cells. Progesterone significantly down-regulated key components of the mTOR pathway. We conclude that the human myometrium differentially expresses mTOR signalling components and they can be regulated by progesterone. This article is part of a Special Issue entitled 'Pregnancy and Steroids'.This research was funded by National Institutes of Health Grant ESO12961
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