107 research outputs found

    Usefulness and limitations of pollen characters in environmental studies based on Viola L. species (sect. Melanium Ging.)

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    The aim of these studies was to determine the effect of environmental pollution on pollen development. Pollen heteromorphism (the presence of pollen morphs differing in aperture number in one flower of a plant), pollen viability (stainability) and pollen grain size in European metallophytes from sect. Melanium Ging. (Viola L., Violaceae) were analyzed by SEM and histochemical staining.Plants’ tolerance to heavy metals is positively correlated with their pollen viability, which should be termed stainability as it depends on the staining method applied and is not correlated with pollen germination. Abortive pollen can be produced as an effect of heavy metals but also may result from hybridization, a very common phenomenon in pansies. Pollen stainability in hybrids can be high (even exceeding 70%) or low (barely above 20%), and stainable pollen grains can differ greatly in size (from very small to giant), indicating a cytological imbalance resulting from disturbed meiosis. The number of pollen apertures is an adaptive character in facultative metallophytes. Plants from a metallicolous population produced a wider range of aperture number (3, 4, 5) than plants from a non-metallicolous population, which developed only 4- and 5-aperturate pollen. Three-aperturate longer-lived pollen are favored in the harsh conditions of a metal-polluted environment

    EVALUATION AND CALIBRATION OF FIXED-WING UAV MOBILE MAPPING SYSTEM EQUIPPED WITH LIDAR AND OPTICAL SENSORS

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    In this paper, a mobile mapping system mounted on the UAV is presented and evaluated. The NEO3 UAV platform is an 11 kg fixed-wing designed by the MSP company. The UAV is equipped with a Riegl miniVUX-1UAV laser scanner, which is integrated with the GNSS/INS system of Applanix APX-15 UAV and two Sony Alfa 6000 cameras collecting images in the following spectrum: visible for the first camera and near-infrared for the second camera. The UAV mobile system presented is dedicated to the acquisition of multisource data for levee monitoring using active and passive remote sensing data. In this paper, the effectiveness of the ultralight laser scanner, which has not been mounted on the fixed-wing platforms so far, was verified in the experiment with respect to data density and accuracy. The example analyses were conducted using ground control points and surfaces measured with a terrestrial laser scanner and visible in point clouds obtained with a dense image matching algorithm. Analyses showed that the achieved accuracy is much related to trajectory accuracy. The final DTM created from the data collected during the float status of the GNSS measurements of the trajectory provided twice less accurate data than during fixed status (vertical error approximately 20 cm and 10 cm respectively)

    Burnout syndrome among caregivers of children suffering from epilepsy

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    Zespół wypalenia jest to stan fizycznego i psychicznego wyczerpania powstający w wyniku działania długotrwałych uczuć negatywnych. Na zespół wypalenia narażone są osoby długotrwale zaangażowane w udzielanie pomocy (lekarze, terapeuci, pielęgniarki, opiekunowie). Celem niniejszej pracy była ocena nasilenia zespołu wypalenia wśród opiekunów dzieci chorujących na padaczkę. W ankietowym badaniu oceniono 99 opiekunów dzieci chorych na padaczkę, którzy wypełnili Kwestionariusz Wypalenia Maslach i Inwentarz Depresji Becka. U żadnego z badanych opiekunów nie zaobserwowano objawów depresji. Stwierdzono, że istnieje dodatnia korelacja pomiędzy czasem trwania choroby, wiekiem dziecka oraz wiekiem opiekuna a poziomem wyczerpania emocjonalnego. Osoby opiekujące się chorym dzieckiem samotnie, bez wsparcia rodziny, cechowały się wyższymi wartościami wyczerpania emocjonalnego oraz depersonalizacji, a także niższą samooceną.Burnout syndrome is a condition of physical and mental exhaustion resulting from chronic exposure to negative emotions. Subjects involved in helping others for a long time (e.g. doctors, nurses, caregivers etc.) are at risk of developing burnout syndrome. The aim of this study was to assess the intensity of the burnout syndrome among caregivers of children suffering from epilepsy. We assessed 99 caregivers of children. They were asked to fill in the Maslach Burnout Inventory and Beck’s Depresion Index. We have found no symptoms of depression in any of the caregivers. There is a positive correlation between time passed from the diagnosis, age of the child , age of the caregiver and the level of emotional exhaustion. Subjects taking care of a child lonely, without any familial support had higher results in subscales of emotional exhaustion and depersonalisation. They were also characterised by lower self-esteem as well

    Arabinogalactan-protein and pectin epitopes in relation to an extracellular matrix surface network and somatic embryogenesis and callogenesis in Trifolium nigrescens Viv

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    The formation of an extracellular matrix surface network (ECMSN), and associated changes in the distribution of arabinogalactan-protein and pectin epitopes, have been studied during somatic embryogenesis (SE) and callogenesis of Trifolium nigrescens Viv. Scanning electron microscopy observations revealed the occurrence of an ECMSN on the surface of cotyledonary-staged somatic embryos as well as on the peripheral, non-regenerating callus cells. The occurrence of six AGP (JIM4, JIM8, JIM13, JIM16, LM2, MAC207) and four pectin (JIM5, JIM7, LM5, LM6) epitopes was analysed during early stages of SE, in cotyledonary-staged somatic embryos and in non-embryogenic callus using monoclonal antibodies. The JIM5 low methyl-esterified homogalacturonan (HG) epitope localized to ECMSN on the callus surface but none of the epitopes studied were found to localize to ECMSN over mature somatic embryos. The LM2 AGP epitope was detected during the development of somatic embryos and was also observed in the cell walls of meristematic cells from which SE was initiated. The pectic epitopes JIM5, JIM7, LM5 and LM6 were temporally regulated during SE. The LM6 arabinan epitope, carried by side chains of rhamnogalacturonan-I (RG-I), was detected predominantly in cells of embryogenic swellings, whilst the LM5 galactan epitope of RG-I was uniformly distributed throughout the ground tissue of cotyledonary-staged embryoids but not detected at the early stages of SE. Differences in the distribution patterns of low and high methyl-esterified HG were detected: low ester HG (JIM5 epitope) was most abundant during the early steps of embryo formation and highly methyl-esterified form of HG (JIM7 epitope) became prevalent during embryoid maturation

    The TT genotype of methylenetetrahydrofolate reductase 677C>T polymorphism increases the susceptibility to pediatric ischemic stroke: meta-analysis of the 822 cases and 1,552 controls

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    The 677C>T polymorphism within methylenetetrahydrofolate reductase (MTHFR) gene is related to an elevated level of homocysteine. Thus it may be considered as a genetic risk factor in ischemic stroke. Apparently studies of this type of polymorphism in childhood stroke have shown conflicting results. We performed meta-analysis of all the data that are available in relation with MTHFR polymorphism and the risk of ischemic stroke in children. We searched PubMed (last search dated December 2010) using “MTHFR polymorphism”, “ischemic stroke” “child”, “children”, “pediatric stroke” as keywords and reference lists of studies and reviews on the topic. Finally, 15 case–control studies corresponded to the inclusion criteria for meta-analysis. These studies involved the total number of 822 children and adolescents after ischemic stroke and 1,552 control subjects. Fixed or random effects models were used depending on the heterogeneity between the studies. The association between ischemic stroke and 677C>T polymorphism within MTHFR gene was observed in three of the studies. The pooled analysis showed that TT genotype of MTHFR gene is more common in stroke patients than in controls (p = 0.0402, odds ratio = 1.57, 95 % confidence interval 1.02–2.41). The Egger’s test did not reveal presence of a publication bias. The results based on a sizeable group of cases and controls have proved that the 677C>T polymorphism in MTHFR gene is associated with the development of ischemic stroke in children
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