265 research outputs found

    The role of glacier mice in the invertebrate colonisation of glacial surfaces: the moss balls of the Falljökull, Iceland

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    Glacier surfaces have a surprisingly complex ecology. Cryoconite holes contain diverse invertebrate communities while other invertebrates, such as Collembola often graze on algae and windblown dead organic on the glacier surface. Glacier mice (ovoid unattached moss balls) occur on some glaciers worldwide. Studies of these glacier mice have concentrated on their occurrence and mode of formation. There are no reports of the invertebrate communities. But, such glacier mice may provide a suitable favourable habitat and refuge for a variety of invertebrate groups to colonise the glacier surface. Here we describe the invertebrate fauna of the glacier mice (moss balls) of the Falljökull, Iceland. The glacier mice were composed of Racomitrium sp. and varied in size from 8.0 to 10.0 cm in length. All glacier mice studied contained invertebrates. Two species of Collembola were present. Pseudisotoma sensibilis (Tullberg, 1876) was numerically dominant with between 12 and 73 individuals per glacier mouse while Desoria olivacea (Tullberg, 1871) occurred but in far lower numbers. Tardigrada and Nematoda had mean densities of approximately 200 and 1,000 respectively. No Acari, Arachnida or Enchytraeidae were observed which may be related to the difficulty these groups have in colonizing the glacier mice. We suggest that glacier mice provide an unusual environmentally ameliorated microhabitat for an invertebrate community dwelling on a glacial surface. The glacier mice thereby enable an invertebrate fauna to colonise an otherwise largely inhospitable location with implications for carbon flow in the system

    Impact of the Covid-19 Pandemic on ALS Care in the UK

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    The Covid-19 pandemic has impacted healthcare. Our aim was to identify how amyotrophic lateral sclerosis (ALS) care in the UK has been affected by the pandemic by exploring the experiences of people living with ALS (plwALS), healthcare professionals (HCPs) working with plwALS, and ALS care centers. Three surveys were carried out to explore the experiences of plwALS, HCPs and ALS care centers during the pandemic. Quantitative data were analyzed using descriptive and inferential statistics and triangulated with the qualitative data which were analyzed thematically. Responses from 53 plwALS, 73 HCPs and 23 ALS care centers were analyzed. Five main themes were identified: keeping safe, losses, negative emotions, delivering care and alternative care delivery in a pandemic. PlwALS and HCPs felt that care was sub-optimal as a result of the pandemic. Changes to care included longer waiting times and face-to-face appointments being canceled or replaced by virtual consultations. While benefits of virtual consultations were reported, concerns were raised about incomplete clinical assessments and the disruption of provision of testing and interventions. ALS care has changed as a result of the pandemic. Patients have had a lack of face-to-face contact with HCPs and have experienced delays to investigations and treatments. PlwALS and HCPs were concerned about the impact of this change, but the long-term implications remain unclear. We propose recommendations for HCPs caring for plwALS, that will promote continuity of evidenced based care in the context of a pandemic

    Retroperitoneal Castleman's tumor and paraneoplastic pemphigus: report of a case and review of the literature

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    BACKGROUND: Castleman's disease is a rare lymphoproliferative syndrome. Its etiology and pathogenesis are unclear. The disease can be occasionally associated with a paraneoplastic pemphigus (PNP), an autoimmune mucocutaneous disorder commonly seen in neoplasms of lymphocytic origin. CASE PRESENTATION: We present a case of a 63-year old male patient who was referred for surgical treatment of a lately diagnosed retroperitoneal pelvic mass. The patient had been already treated for two years due to progressive diffuse cutaneous lesions histologically consistent with lichen ruber verucosus and pemphigus vulgaris. Intraoperatively a highly vascularized solid mass occupying the small pelvis was resected after meticulous vascular ligation and hemostasis. After surgery and following immunosuppressive treatment a clear remission of the skin lesions was observed. CONCLUSION: Castleman's tumor should be always suspected when a retroperitoneal mass is combined with PNP. In a review of the literature we found 37 additional cases. Complete surgical resection of the tumor can be curative in most of the cases

    Intrathoracic fire during preparation of the left internal thoracic artery for coronary artery bypass grafting

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    A surgical fire is a serious complication not previously described in the literature with regard to the thoracic cavity. We report a case in which an intrathoracic fire developed following an air leak combined with high pressure oxygen ventilation in a patient with severe chronic obstructive pulmonary disease. The patient presented to our institution with diffuse coronary artery disease and angina pectoris. He was treated with coronary artery bypass graft surgery, including left internal thoracic artery harvesting. Additionally to this rare presentation of an intrathoracic fire, a brief review of surgical fires is included to this paper

    Right hemisphere has the last laugh: neural dynamics of joke appreciation

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    Understanding a joke relies on semantic, mnemonic, inferential, and emotional contributions from multiple brain areas. Anatomically constrained magnetoencephalography (aMEG) combining high-density whole-head MEG with anatomical magnetic resonance imaging allowed us to estimate where the humor-specific brain activations occur and to understand their temporal sequence. Punch lines provided either funny, not funny (semantically congruent), or nonsensical (incongruent) replies to joke questions. Healthy subjects rated them as being funny or not funny. As expected, incongruous endings evoke the largest N400m in left-dominant temporo-prefrontal areas, due to integration difficulty. In contrast, funny punch lines evoke the smallest N400m during this initial lexical–semantic stage, consistent with their primed “surface congruity” with the setup question. In line with its sensitivity to ambiguity, the anteromedial prefrontal cortex may contribute to the subsequent “second take” processing, which, for jokes, presumably reflects detection of a clever “twist” contained in the funny punch lines. Joke-selective activity simultaneously emerges in the right prefrontal cortex, which may lead an extended bilateral temporo-frontal network in establishing the distant unexpected creative coherence between the punch line and the setup. This progression from an initially promising but misleading integration from left frontotemporal associations, to medial prefrontal ambiguity evaluation and right prefrontal reprocessing, may reflect the essential tension and resolution underlying humor

    Causes and Correlates of Calf Mortality in Captive Asian Elephants (Elephas maximus)

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    Juvenile mortality is a key factor influencing population growth rate in density-independent, predation-free, well-managed captive populations. Currently at least a quarter of all Asian elephants live in captivity, but both the wild and captive populations are unsustainable with the present fertility and calf mortality rates. Despite the need for detailed data on calf mortality to manage effectively populations and to minimize the need for capture from the wild, very little is known of the causes and correlates of calf mortality in Asian elephants. Here we use the world's largest multigenerational demographic dataset on a semi-captive population of Asian elephants compiled from timber camps in Myanmar to investigate the survival of calves (n = 1020) to age five born to captive-born mothers (n = 391) between 1960 and 1999. Mortality risk varied significantly across different ages and was higher for males at any age. Maternal reproductive history was associated with large differences in both stillbirth and liveborn mortality risk: first-time mothers had a higher risk of calf loss as did mothers producing another calf soon (<3.7 years) after a previous birth, and when giving birth at older age. Stillbirth (4%) and pre-weaning mortality (25.6%) were considerably lower than those reported for zoo elephants and used in published population viability analyses. A large proportion of deaths were caused by accidents and lack of maternal milk/calf weakness which both might be partly preventable by supplementary feeding of mothers and calves and work reduction of high-risk mothers. Our results on Myanmar timber elephants with an extensive keeping system provide an important comparison to compromised survivorship reported in zoo elephants. They have implications for improving captive working elephant management systems in range countries and for refining population viability analyses with realistic parameter values in order to predict future population size of the Asian elephant

    Inhibition of PIKfyve by YM-201636 Dysregulates Autophagy and Leads to Apoptosis-Independent Neuronal Cell Death

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    The lipid phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P-2), synthesised by PIKfyve, regulates a number of intracellular membrane trafficking pathways. Genetic alteration of the PIKfyve complex, leading to even a mild reduction in PtdIns(3,5)P-2 results in marked neurodegeneration via an uncharacterised mechanism. In the present study we have shown that selectively inhibiting PIKfyve activity, using YM-201636, significantly reduces the survival of primary mouse hippocampal neurons in culture. YM-201636 treatment promoted vacuolation of endolysosomal membranes followed by apoptosis-independent cell death. Many vacuoles contained intravacuolar membranes and inclusions reminiscent of autolysosomes. Accordingly, YM-201636 treatment increased the level of the autophagosomal marker protein LC3-II, an effect that was potentiated by inhibition of lysosomal proteases, suggesting that alterations in autophagy could be a contributing factor to neuronal cell death

    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
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