2,351 research outputs found

    Widespread habitat change through paludification as an interactive mechanism in mass extinction events

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    The study of mass extinction events has largely focused on defining an environmental factor or factors that might account for specific patterns of faunal demise. Several hypotheses elaborate on how a given environmental factor might affect fauna directly, but differentially, causing extinction in certain taxa but not others. Yet few studies have considered specific habitat changes that might result from natural vegetation processes or from perturbations of vegetation. The role of large-scale habitat change induced by natural successional change from forest to bog (paludification) is examined and how large perturbations (e.g., volcanism, bolide impacts) might favor increased rates of paludification and consequent mass extinctions is considered. This hypothesis has an advantage over other hypotheses for mass extinctions in that modern day analogs of paludification are common throughout the world, thus allowing for considerable testing

    Autologous Fat Grafting Reduces Pain in Irradiated Breast: A Review of Our Experience

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    Introduction. Pain syndromes affect women after conservative and radical breast oncological procedures. Radiation therapy influences their development. We report autologous fat grafting therapeutical role in treating chronic pain in irradiated patients. Materials and Methods. From February 2006 to November 2014, we collect a total of 209 patients who meet the definition of "Postmastectomy Pain Syndrome" (PMPS) and had undergone mastectomy with axillary dissection (113 patients) or quadrantectomy (96 patients). Both procedures were followed by radiotherapy. We performed fat grafting following Coleman's procedure. Mean amount of adipose tissue injected was 52\u2009cc (\ub18.9\u2009cc) per breast. Seventy-eight in 209 patients were not treated surgically and were considered as control group. Data were gathered through preoperative and postoperative VAS questionnaires; analgesic drug intake was recorded. Results. The follow-up was at 12 months (range 11.7-13.5 months). In 120 treated patients we detected pain decrease (mean \ub1 SD point reduction, 3.19 \ub1 2.86). Forty-eight in 59 patients stopped their analgesic drug therapy. Controls reported a mean \ub1 SD decrease of pain of 1.14 \ub1 2.72. Results showed that pain decreased significantly in patients treated (p < 0.005, Wilcoxon rank-sum test). Conclusion. Our 8-year experience confirms fat grafting effectiveness in decreasing neuropathic pain

    Functional fat injection under local anesthesia to treat severe postsurgical dysphagia, case report

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    Background: In this study, we present the first application of functional fat injection performed under local anesthesia in the treatment of severe dysphagia secondary to head and neck cancer surgery. Methods: Functional fat injection was performed using a transcervical approach. Control of injection depth and site was performed through a transnasal flexible endoscope. The effect of surgery was evaluated through videofluoroscopy (VFS), Fiberendoscopic Evaluation of Swallowing (FEES), Functional Oral Intake Scale (FOIS), and Eating Assessment Tool-10 (EAT-10). Results: Before the functional fat injection, the patient was dependent on permanent tube feeding; the VFS and FEES revealed a severe impairment of swallowing abilities. The EAT-10 scored 26. Twelve months after surgery, the patient was on oral diet, the VFS demonstrated mild to moderate dysphagia, the FEES demonstrated aspiration only with liquids and the EAT-10 improved. Conclusion: Functional fat injection under local anesthesia could be useful in the treatment of chronic dysphagia in selected patients

    Self-Referential Noise and the Synthesis of Three-Dimensional Space

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    Generalising results from Godel and Chaitin in mathematics suggests that self-referential systems contain intrinsic randomness. We argue that this is relevant to modelling the universe and show how three-dimensional space may arise from a non-geometric order-disorder model driven by self-referential noise.Comment: Figure labels correcte

    Precision measurements of Linear Scattering Density using Muon Tomography

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    We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.Comment: 16 pages, 4 figure

    Human adipose-derived stromal cells transplantation prolongs reproductive lifespan on mouse models of mild and severe premature ovarian insufficiency

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    Background Although recent studies have investigated the ability of Mesenchymal Stromal Cells (MSCs) to alleviate short-term ovarian damage in animal models of chemotherapy-induced Premature Ovarian Insufficiency (POI), no data are available on reproductive lifespan recovery, especially in a severe POI condition. For this reason, we investigated the potential of MSCs isolated from human adipose tissue (hASCs), since they are easy to harvest and abundant, in ameliorating the length and performance of reproductive life in both mild and severe chemotherapy-induced murine POI models. Methods Mild and severe POI models were established by intraperitoneally administering a light (12 mg/kg busulfan + 120 mg/kg cyclophosphamide) or heavy (30 mg/kg busulfan + 120 mg/kg cyclophosphamide) dose of chemotherapy, respectively, in CD1 mice. In both cases, a week later, 1 × 106 hASCs were transplanted systemically through the tail vein. After four additional weeks, some females were sacrificed to collect ovaries for morphological evaluation. H&amp;E staining was performed to assess stroma alteration and to count follicle numbers; immunofluorescence staining for αSMA was used to analyse vascularization. Of the remaining females, some were mated after superovulation to collect 2-cell embryos in order to evaluate their pre-implantation developmental capacity in vitro, while others were naturally mated to monitor litters and reproductive lifespan length. F1 litters’ weight, ovaries and reproductive lifespan were also analysed. Results hASC transplantation alleviated ovarian weight loss and size decrease and reduced alterations on ovarian stroma and vasculature, concurrently preventing the progressive follicle stockpile depletion caused by chemotherapy. These effects were associated with the preservation of the oocyte competence to develop into blastocyst in vitro and, more interestingly, with a significant decrease of chemotherapy-induced POI features, like shortness of reproductive lifespan, reduced number of litters and longer time to plug (the latter only presented in the severe POI model). Conclusion Human ASC transplantation was able to significantly reduce all the alterations induced by the chemotherapeutic treatment, while improving oocyte quality and prolonging reproductive functions, thus counteracting infertility. These results, strengthened by the use of an outbred model, support the potential applications of hASCs in women with POI, nowadays mainly induced by anticancer therapies

    Suppression of anomalous impurity transport in NBI-heated W7-X plasmas

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    Radial impurity density profiles in two Wendelstein 7-X (W7-X) experiments heated by neutral beam injection (NBI) are analyzed with respect to their impurity transport properties. Local impurity densities are derived from charge exchange reactions with the W7-X NBI system using simulated neutral densities cross-validated with beam emission spectroscopy. Impurity profiles of argon and carbon are found to show an evolving central accumulation inside half radius. The properties of the underlying impurity transport are assessed using the one-dimensional transport code pySTRAHL. Comparisons between simulation and experiment indicate transport dominated by anomalous diffusion outside half radius. The observed central impurity accumulation is found to match best simulations with purely (neo-)classical transport in the accumulation region. This data implies a suppression of the anomalous impurity transport channel to below 35% of the (neo-)classical one. Experimental data is found to be matched best when invoking a time evolving, inward propagating zone where anomalous impurity transport is suppressed. An additional central power deposition into a plasma with central impurity accumulation via electron cyclotron resonance heating is found to affect the (neo-)classical transport components in case of operation times below 200 ms only. For longer operation times, it is found to re-introduce an altered level of anomalous diffusion. The existence of an inward directed anomalous pinch as an alternative explanation for the central impurity accumulation cannot explain the observed profiles

    Variables in Concept Graphs

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    Cosmogenic ^(10)Be and ^(36)Cl geochronology of offset alluvial fans along the northern Death Valley fault zone: Implications for transient strain in the eastern California shear zone

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    The northern Death Valley fault zone (NDVFZ) has long been recognized as a major right-lateral strike-slip fault in the eastern California shear zone (ECSZ). However, its geologic slip rate has been difficult to determine. Using high-resolution digital topographic imagery and terrestrial cosmogenic nuclide dating, we present the first geochronologically determined slip rate for the NDVFZ. Our study focuses on the Red Wall Canyon alluvial fan, which exposes clean dextral offsets of seven channels. Analysis of airborne laser swath mapping data indicates ∼297 ± 9 m of right-lateral displacement on the fault system since the late Pleistocene. In situ terrestrial cosmogenic ^(10)Be and ^(36)Cl geochronology was used to date the Red Wall Canyon fan and a second, correlative fan also cut by the fault. Beryllium 10 dates from large cobbles and boulders provide a maximum age of 70 +22/−20 ka for the offset landforms. The minimum age of the alluvial fan deposits based on ^(36)Cl depth profiles is 63 ± 8 ka. Combining the offset measurement with the cosmogenic ^(10)Be date yields a geologic fault slip rate of 4.2 +1.9/−1.1 mm yr^(−1), whereas the ^(36)Cl data indicate 4.7 +0.9/−0.6 mm yr^(−1) of slip. Summing these slip rates with known rates on the Owens Valley, Hunter Mountain, and Stateline faults at similar latitudes suggests a total geologic slip rate across the northern ECSZ of ∼8.5 to 10 mm yr^(−1). This rate is commensurate with the overall geodetic rate and implies that the apparent discrepancy between geologic and geodetic data observed in the Mojave section of the ECSZ does not extend north of the Garlock fault. Although the overall geodetic rates are similar, the best estimates based on geology predict higher strain rates in the eastern part of the ECSZ than to the west, whereas the observed geodetic strain is relatively constant
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