842 research outputs found

    How Much Variation in Land Surface Phenology can Climate Oscillation Modes Explain at the Scale of Mountain Pastures in Kyrgyzstan?

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    Climate oscillation modes can shape weather across the globe due to atmospheric teleconnections. We built on the findings of a recent study to assess whether the impacts of teleconnections are detectable and significant in the early season dynamics of highland pastures across five rayons in Kyrgyzstan. Specifically, since land surface phenology (LSP) has already shown to be influenced by snow cover seasonality and terrain, we investigated here how much more explanatory and predictive power information about climatic oscillation modes might add to explain variation in LSP. We focused on seasonal values of five climate oscillation indices that influence vegetation dynamics in Central Asia. We characterized the phenology in highland pastures with metrics derived from LSP modeling using Landsat NDVI time series together with MODIS land surface temperature (LST) data: Peak Height (PH), the maximum modeled NDVI and Thermal Time to Peak (TTP), the quantity of accumulated growing degree-days based on LST required to reach PH. Next, we calculated two metrics of snow cover seasonality from MODIS snow cover composites: last date of snow (LDoS), and the number of snow covered dates (SCD). For terrain features, we derived elevation, slope, and TRASP index as linearization of aspect. First, we used Spearman’s rank correlation to assess the geographical differentiation of land surface phenology metrics responses to environmental variables. PH showed weak correlations with TTP (positive in western but negative in eastern rayons), and moderate relationships with LDoS and SCD only in one northeastern rayon. Slope was weakly related to PH, while TRASP showed a consistent moderate negative correlation with PH. A significant but weak negative correlation was found between PH and SCAND JJA, and a significant weak positive correlation with MEI MAM. TTP showed consistently strong negative relationships with LDoS, SCD, and elevation. Very weak positive correlations with TTP were found for EAWR DJF, AMO DJF, and MEI DJF in western rayons only. Second, we used Partial Least Squares regression to investigate the role of oscillation modes altogether. PLS modelling of TTP showed that thermal time accumulation could be explained mostly by elevation and snow cover metrics, leading to reduced models explaining 55 to 70% of observed variation in TTP. Variable selection indicated that NAO JJA, AMO JJA and SCAND MAM had significant relationships with TTP, but their input of predictive power was neglible. PLS models were able to explain up to 29% of variability in PH. SCAND JJA and MEI MAM were shown to be significant predictors, but adding them into models did not influence modeling performance. We concluded the impacts of climate oscillation anomalies were not detectable or significant in mountain pastures using LSP metrics at fine spatial resolution. Rather, at a 30m resolution, the indirect effects of seasonal climatic oscillations are overridden by terrain influences (mostly elevation) and snow cover timing. Whether climate oscillation mode indices can provide some new and useful information about growing season conditions remains a provocative question, particularly in light of the multiple environmental challenges facing the agropastoralism livelihood in montane Central Asia

    The Thebesian valve and its significance for electrophysiologists

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    Background: Invasive cardiac procedures, such as arrhythmia ablation, cardiac resynchronisation therapy, percutaneous mitral annuloplasty and retrograde cardioplegia delivery require cannulation of the coronary sinus (CS). Detailed knowledge of the CS ostium region, including recognition of the presence of the Thebesian valve which sometimes covers the sinus, is a key to successfully carryout such procedures.Materials and methods: In the present study, 160 autopsied human hearts from both sexes were examined for the presence of the Thebesian valve. If identified, the histological structure of the valve was studied.Results: Five types of the CS valve were distinguished; all of them presented with a typical histological structure with the exception of the cord-like type, in which cells were similar to those of the conduction system of the heart.Conclusions: Proper identification of the CS valve and analysis of its size and histological features could have important implications for electrophysiologists

    Fatty foci within the heart and the accompanying changes in the coronary arteries diagnosed in electrocardiogram-gated multislice computed tomography of the heart

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    Background: The purpose of our study was to analyse the relationship between fatty foci within the heart and the accompanying changes in the coronary arteries supplying the relevant heart chambers in a large group of patients referred to multi-slice computed tomography with electrocardiogram-gating examinations (ECG-MSCT) for various clinical reasons. Materials and methods: The ECG-MSCT examinations of 1,830 consecutive patients were analysed. The examinations were performed using 8-row (1,015 patients) and 64-row (815 patients) MSCT, in pre- and postcontrast scanning. In the group of patients with fatty foci within the heart the concomitant changes in the coronary arteries were assessed. It was analysed: the type of changes in the arteries; the relationship between the locations of the fatty deposits and the occurrence and type of changes in the coronary arteries. Results: In 200 (10.9%) subjects fatty foci within the heart (112 men; 88 women; mean age 57.8) were detected. The distribution of the fat was as follows: right ventricle (RV) — 32.5%, left ventricle (LV) — 22.0%, biventricular — 45.5%. One hundred and seventy-two patients had concomitant changes in the coronary arteries. In patients with normal coronary arteries, significantly more often fatty deposits were localised within RV. Fat was primarily located subendocardially in the LV in patients with atherosclerosis in the left anterior descending artery (p < 0.001), in the right coronary artery (RCA) (p = 0.003), and in the left circumflex artery (LCX) (p < 0.001). Subpericardial locations of fatty deposits in RV significantly correlated with RCA bridging (p < 0.02); the subpericardial location of fat in LV significantly correlated with LCX bridging (p = 0.001). Conclusions: Fatty replacement of the myocardium is common, occurring in up to 10% of diagnosed patients and the majority of this group had concomitant changes in the coronary arteries. However, in the group of patients without changes in the coronary arteries, the fatty deposits locate themselves significantly more frequently within the RV

    Anatomy and clinical significance of the maxillary nerve: a literature review

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    Background: The aim of this paper was to summarise the anatomical knowledge on the subject of the maxillary nerve and its branches, and to show the clinical usefulness of such information in producing anaesthesia in the region of the maxilla. Materials and methods: A literature search was performed in Pubmed, Scopus, Web of Science and Google Scholar databases, including studies published up to June 2014, with no lower data limit. Results: The maxillary nerve (V2) is the middle sized branch of the trigeminal nerve — the largest of the cranial nerves. The V2 is a purely sensory nerve supplying the maxillary teeth and gingiva, the adjoining part of the cheek, hard and soft palate mucosa, pharynx, nose, dura mater, skin of temple, face, lower eyelid and conjunctiva, upper lip, labial glands, oral mucosa, mucosa of the maxillary sinus, as well as the mobile part of the nasal septum. The branches of the maxillary nerve can be divided into four groups depending on the place of origin i.e. in the cranium, in the sphenopalatine fossa, in the infraorbital canal, and on the face. Conclusions: This review summarises the data on the anatomy and variations of the maxillary nerve and its branches. A thorough understanding of the anatomy will allow for careful planning and execution of anaesthesiological and surgical procedures involving the maxillary nerve and its branches

    Chromosomal abnormalities in diagnostics of ovarian cance

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    ECG-gated multi-slice computed tomography in the detection of atrial septal aneurysms

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    An atrial septal aneurysm (ASA) is an uncommon cardiac abnormality. Clinical manifestation of this abnormality remains unclear: some authors have suggested an association between ASA and arrhythmias or between ASA and cerebral ischaemia. A major role in the diagnosis of ASA to date has been played by transoesophageal echocardiography and transthoracic echocardiography. The purpose of this paper is to present the role of multi-slice computed tomography with ECG gating in the detection and analysis of ASA. (Folia Morphol 2008; 67: 126–128

    A Thioredoxin Domain-Containing Protein Interacts with Pepino mosaic virus Triple Gene Block Protein 1

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    Pepino mosaic virus (PepMV) is a mechanically-transmitted tomato pathogen of importance worldwide. Interactions between the PepMV coat protein and triple gene block protein (TGBp1) with the host heat shock cognate protein 70 and catalase 1 (CAT1), respectively, have been previously reported by our lab. In this study, a novel tomato interactor (SlTXND9) was shown to bind the PepMV TGBp1 in yeast-two-hybrid screening, in vitro pull-down and bimolecular fluorescent complementation (BiFC) assays. SlTXND9 possesses part of the conserved thioredoxin (TRX) active site sequence (W__PC vs. WCXPC), and TXND9 orthologues cluster within the TRX phylogenetic superfamilyclosesttophosducin-likeprotein-3. InPepMV-infectedandhealthyNicotianabenthamiana plants,NbTXND9mRNAlevelswerecomparable,andexpressionlevelsremainedstableinbothlocal and systemic leaves for 10 days post inoculation (dpi), as was also the case for catalase 1 (CAT1). To localize the TXND9 in plant cells, a polyclonal antiserum was produced. Purified α-SlTXND9 immunoglobulin (IgG) consistently detected a set of three protein bands in the range of 27–35 kDa, in the 1000 and 30,000 g pellets, and the soluble fraction of extracts of healthy and PepMV-infected N. benthamiana leaves, but not in the cell wall. These bands likely consist of the homologous protein NbTXND9 and its post-translationally modified derivatives. On electron microscopy, immuno-gold labellingofultrathinsectionsofPepMV-infectedN.benthamianaleavesusingα-SlTXND9IgGrevealed particle accumulation close to plasmodesmata, suggesting a role in virus movement. Taken together, this study highlights a novel tomato-PepMV protein interaction and provides data on its localization in planta. Currently, studies focusing on the biological function of this interaction during PepMV infection are in progress

    The presence of B7-H4+ macrophages and CD25+CD4+ and FOXP3+ regulatory T cells in the microenvironment of nasal polyps - a preliminary report.

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    The nasal polyp (NP) seems to represent the end-stage of longstanding inflammation in patients with chronic rhinosinusitis. The aim of our study has been to evaluate the presence of two regulatory cell populations in the microenvironment of NP: CD4+CD25high Foxp3+ (Treg) cells and B7-H4-expressing macrophages. Treg cells are actively able to inhibit T lymphocytes, while the population of B7-H4-expressing macrophages has recently been described as characterized by a regulatory function similar to that of Treg cells. For our study, we evaluated 14 NP tissue samples. The samples were divided into two main groups, eosinophilic (NP) and lymphocytic (NP), according to the predominant type of immune cell infiltration. The presence of Treg cells and B7-H4 positive macrophages in the samples was analyzed by FACS. Treg cells and B7-H4-expressing macrophages were identified in all the examined nasal polyps. The percentages of both Treg cells and of B7H4 positive cells found in the eosinophilic nasal polyps were higher than those found in the lymphocytic nasal polyps. Treg cells and B7H4+ macrophage subpopulations were present in the NP microenvironment and the alterations in their percentages were related to a distinct pattern of immune cell infiltration

    COST 733 - WG4: Applications of weather type classification

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    The main objective of the COST Action 733 is to achieve a general numerical method for assessing, comparing and classifying typical weather situations in the European regions. To accomplish this goal, different workgroups are established, each with their specific aims: WG1: Existing methods and applications (finished); WG2: Implementation and development of weather types classification methods; WG3: Comparison of selected weather types classifications; WG4: Testing methods for various applications. The main task of Workgroup 4 (WG4) in COST 733 implies the testing of the selected weather type methods for various classifications. In more detail, WG4 focuses on the following topics:• Selection of dedicated applications (using results from WG1), • Performance of the selected applications using available weather types provided by WG2, • Intercomparison of the application results as a results of different methods • Final assessment of the results and uncertainties, • Presentation and release of results to the other WGs and external interested • Recommend specifications for a new (common) method WG2 Introduction In order to address these specific aims, various applications are selected and WG4 is divided in subgroups accordingly: 1.Air quality 2. Hydrology (& Climatological mapping) 3. Forest fires 4. Climate change and variability 5. Risks and hazards Simultaneously, the special attention is paid to the several wide topics concerning some other COST Actions such as: phenology (COST725), biometeorology (COST730), agriculture (COST 734) and mesoscale modelling and air pollution (COST728). Sub-groups are established to find advantages and disadvantages of different classification methods for different applications. Focus is given to data requirements, spatial and temporal scale, domain area, specifi
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