Analysis of mating system in two Pinus cembra L. populations of the Ukrainian Carpathians

In natural pine populations, a mixed mating system is typical,characterized by the proportions of selfed and outcrossed seeds. Swiss stone pine(Pinus cembra L.) is one of the least studied European conifers in this respect. The mating system of six polymorphic allozyme loci were studied in haploid megagametophytes and diploid open-pollinated embryos in two stands located in theEast Carpathians. In the 'Gorgany' population (24 trees, 198 seeds) the mean singlelocus estimated outcrossing rate (ts) was 0.731, and the multilocus estimate (tm) was 0.773. In the 'Yayko' population the outcrossing rate was lower (27 trees, 213 seeds, ts=0.645, tm=0.700), suggesting 23-30% of seeds are self-pollinated. Correlation ofoutcrossing rate estimates among loci was less than 1, (0.300 in 'Gorgany' and 0.469 in 'Yayko') indicating biparental inbreeding occurred. Differences between tm and ts (0.042 in 'Gorgany' and 0.056 in 'Yayko') can also be influenced by consanguineous mating, indicated by the presence of spatial and genetic family structure. In small isolated populations of Pinus cembra, which are typical for the Carpathian part of the species' range, inbreeding depression may negatively affect seed quality. The high proportion of selfed seeds observed here can be expected in any seedlot of this species and should be taken into account while planning gene conservation orreforestation measures. Maternal trees in these populations showed no heterozygote deficiency at these allozyme loci, and instead showed increased proportions of heterozygotes (inbreeding coefficient FIS = -0.200 in 'Gorgany' and -0.142 in 'Yayko'). Balancing selection may explain heterozygosity levels up to and above equilibrium proportions

Tinkering With Testing:Understanding How Museum Program Design Advances Engineering Learning Opportunities for Children

Using a design-based research approach, we studied ways to advance opportunities for children and families to engage in engineering design practices in an informal educational setting. 213 families with 5–11-year-old children were observed as they visited a tinkering exhibit at a children’s museum during one of three iterations of a program posing an engineering design challenge. Children’s narrative reflections about their experience were recorded immediately after tinkering. Across iterations of the program, changes to the exhibit design and facilitation provided by museum staff corresponded to increased families’ engagement in key engineering practices. In the latter two cycles of the program, families engaged in the most testing, and in turn, redesigning. Further, in the latter cycles, the more children engaged in testing and retesting during tinkering, the more their narratives contained engineering-related content. The results advance understanding and the evidence base for educational practices that can promote engineering learning opportunities for children

A Single Dose of Neuron-Binding Human Monoclonal Antibody Improves Spontaneous Activity in a Murine Model of Demyelination

Our laboratory demonstrated that a natural human serum antibody, sHIgM12, binds to neurons in vitro and promotes neurite outgrowth. We generated a recombinant form, rHIgM12, with identical properties. Intracerebral infection with Theiler's Murine Encephalomyelitis Virus (TMEV) of susceptible mouse strains results in chronic demyelinating disease with progressive axonal loss and neurologic dysfunction similar to progressive forms of multiple sclerosis. To study the effects of rHIgM12 on the motor function of TMEV-infected mice, we monitored spontaneous nocturnal activity over many weeks. Nocturnal behavior is a sensitive measure of rodent neurologic function because maximal activity changes are expected to occur during the normally active night time monitoring period. Mice were placed in activity boxes eight days prior to treatment to collect baseline spontaneous activity. After treatment, activity in each group was continuously recorded over 8 weeks. We chose a long 8-week monitoring period for two reasons: (1) we previously demonstrated that IgM induced remyelination is present by 5 weeks post treatment, and (2) TMEV-induced demyelinating disease in this strain progresses very slowly. Due to the long observation periods and large data sets, differences among treatment groups may be difficult to appreciate studying the original unfiltered recordings. To clearly delineate changes in the highly fluctuating original data we applied three different methods: (1) binning, (2) application of Gaussian low-pass filters (GF) and (3) polynomial fitting. Using each of the three methods we showed that compared to control IgM and saline, early treatment with rHIgM12 induced improvement in both horizontal and vertical motor function, whereas later treatment improved only horizontal activity. rHIgM12 did not alter activity of normal, uninfected mice. This study supports the hypothesis that treatment with a neuron-binding IgM not only protects neurons in vitro, but also influences functional motor improvement

CMV Infection Attenuates the Disease Course in a Murine Model of Multiple Sclerosis

Recent evidence in multiple sclerosis (MS) suggests that active CMV infection may result in more benign clinical disease. The goal of this pilot study was to determine whether underlying murine CMV (MCMV) infection affects the course of the Theiler's murine encephalitis virus (TMEV) induced murine model of MS. A group of eight TMEV-infected mice were co-infected with MCMV at 2 weeks prior to TMEV infection while a second group of TMEV-infected mice received MCMV two weeks post TMEV. We also used 2 control groups, where at the above time points MCMV was replaced with PBS. Outcome measures included (1) monthly monitoring of disability via rotarod for 8 months; (2) in vivo MRI for brain atrophy studies and (3) FACS analysis of brain infiltrating lymphocytes at 8 months post TMEV infection. Co-infection with MCMV influenced the disease course in mice infected prior to TMEV infection. In this group, rotarod detectable motor performance was significantly improved starting 3 months post-infection and beyond (p≤0.024). In addition, their brain atrophy was close to 30% reduced at 8 months, but this was only present as a trend due to low power (p = 0.19). A significant reduction in the proportion of brain infiltrating CD3+ cells was detected in this group (p = 0.026), while the proportion of CD45+ Mac1+ cells significantly increased (p = 0.003). There was also a strong trend for a reduced proportion of CD4+ cells (p = 0.17) while CD8 and B220+ cell proportion did not change. These findings support an immunomodulatory effect of MCMV infection in this MS model. Future studies in this co-infection model will provide insight into mechanisms which modulate the development of demyelination and may be utilized for the development of novel therapeutic strategies

Радіаційна чутливість іонних кристалів. Одновимірна модель. Кристали з дефектами дипольного типу

The occurrence of the radiation color in ionic crystals is the result of the localization of free charge carriers, generated by radiation, on the pre-radiation point defects of the crystalline lattice. With the accumulation of the color centers in the crystals, inverse processes take effect. The free charge carriers recombine at the color centers, and the pre-radiation defects are restored. Prolonged irradiation of the crystals establishes a dynamic equilibrium between the processes of generation of color centers and the illumination effect of X-rays. A one-dimensional model of ionic crystals was proposed, in which calculated were the parameters of radiation sensitivity of fluorite crystals doped with non-isovalent impurities. It is found that at low temperatures regardless of the concentration of the activator in the crystal, the probability of the formation of color centers at the decay of electron-hole pairs is always less than the probability of their destruction. This is explained by the fact that in the first case, the charge carriers interact with electroneutral dipole centers, while in the second case – with charged ones. The probability of the generation of color centers at the decay of the electron-hole pair and the probability of the illumination effect decrease with decreasing concentrations of the activator in the crystal. It is found that at high temperatures regardless of the concentration of the activator in the crystal, the probability of the formation of color centers at the decay of electron-hole pairs is always the same the probability of their destruction. This is explained by the fact that in both cases, the charge carriers interact with electroneutral dipole centers. As the concentration of the activator decreases, the amount of energy consumed to create one complementary pair of color centers increases, and, accordingly, the radiation sensitivity of the crystal drops. As shown by the theoretical calculations, within the framework of this model, boundary concentrations of color centers are determined depending on the concentration of the impurity.Виникнення радіаційного забарвлення в іонних кристалах є результатом локалізації створених радіацією вільних носіїв заряду на дорадіаційних точкових дефектах кристалічної ґратки. Із накопиченням у кристалах центрів забарвлення вступають в дію зворотні процеси. Вільні носії заряду рекомбінують на центрах забарвлення, дорадіаційні дефекти відновлюються. Завдяки довготривалого опромінення кристалів встановлюється динамічна рівновага між процесами генерації центрів забарвлення та висвітлювальною дією рентгенівських променів. Запропоновано одновимірну модель іонних кристалів, у якій було розраховано параметри радіаційної чутливості кристалів флюоритів, легованих неізовалентними домішками. Імовірність генерації центрів забарвлення при розпаді електронно-діркової пари та імовірність висвітлювальної дії знижується зі зменшенням концентрації активатора. За високих температур незалежно від концентрації активатора в кристалі імовірність утворення центрів забарвлення під час розпаду електронно-діркової пари така ж, як імовірність їх руйнування. Це пояснено тим, що в обох випадках носії заряду взаємодіють із електронейтральними дипольними центрами. Зі зменшенням концентрації активатора зростає величина енергії, що витрачається на створення однієї комплементарної пари центрів забарвлення, а відповідно радіаційна чутливість кристала знижується

A hematopoietic contribution to microhemorrhage formation during antiviral CD8 T cell-initiated blood-brain barrier disruption

<p>Abstract</p> <p>Background</p> <p>The extent to which susceptibility to brain hemorrhage is derived from blood-derived factors or stromal tissue remains largely unknown. We have developed an inducible model of CD8 T cell-initiated blood-brain barrier (BBB) disruption using a variation of the Theiler's murine encephalomyelitis virus (TMEV) model of multiple sclerosis. This peptide-induced fatal syndrome (PIFS) model results in severe central nervous system (CNS) vascular permeability and death in the C57BL/6 mouse strain, but not in the 129 SvIm mouse strain, despite the two strains' having indistinguishable CD8 T-cell responses. Therefore, we hypothesize that hematopoietic factors contribute to susceptibility to brain hemorrhage, CNS vascular permeability and death following induction of PIFS.</p> <p>Methods</p> <p>PIFS was induced by intravenous injection of VP2_121-130peptide at 7 days post-TMEV infection. We then investigated brain inflammation, astrocyte activation, vascular permeability, functional deficit and microhemorrhage formation using T2*-weighted magnetic resonance imaging (MRI) in C57BL/6 and 129 SvIm mice. To investigate the contribution of hematopoietic cells in this model, hemorrhage-resistant 129 SvIm mice were reconstituted with C57BL/6 or autologous 129 SvIm bone marrow. Gadolinium-enhanced, T1-weighted MRI was used to visualize the extent of CNS vascular permeability after bone marrow transfer.</p> <p>Results</p> <p>C57BL/6 and 129 SvIm mice had similar inflammation in the CNS during acute infection. After administration of VP2_121-130peptide, however, C57BL/6 mice had increased astrocyte activation, CNS vascular permeability, microhemorrhage formation and functional deficits compared to 129 SvIm mice. The 129 SvIm mice reconstituted with C57BL/6 but not autologous bone marrow had increased microhemorrhage formation as measured by T2*-weighted MRI, exhibited a profound increase in CNS vascular permeability as measured by three-dimensional volumetric analysis of gadolinium-enhanced, T1-weighted MRI, and became moribund in this model system.</p> <p>Conclusion</p> <p>C57BL/6 mice are highly susceptible to microhemorrhage formation, severe CNS vascular permeability and morbidity compared to the 129 SvIm mouse. This susceptibility is transferable with the bone marrow compartment, demonstrating that hematopoietic factors are responsible for the onset of brain microhemorrhage and vascular permeability in immune-mediated fatal BBB disruption.</p

RADIATION SENSITIVITY OF IONIC CRYSTALS. ONE-DIMENSIONAL MODEL. І. IONIC CRYSTALS DOPED WITH ISOVALENT IMPURITIES

Виникнення радіаційного забарвлення в іонних кристалах є результатом локалізації створених радіацією вільних носіїв заряду на дорадіаційних точкових дефектах кристалічної ґратки. Із накопиченням у кристалах центрів забарвлення вступають в дію зворотні процеси. Вільні носії заряду рекомбінують на центрах забарвлення, дорадіаційні дефекти відновлюються. Під час довготривалого опромінення кристалів встановлюється динамічна рівновага між процесами генерації центрів забарвлення та висвітлювальною дією рентгенівських променів. Запропоновано одновимірну модель іонних кристалів, в якій розраховано параметри радіаційної чутливості кристалів флюоритів і лужно-галоїдних кристалів, легованих ізовалентними домішками. Встановлено, що незалежно від концентрації активатора в кристалі імовірність утворення центрів забарвлення при розпаді електронно-діркової пари завжди менша за імовірність їх руйнування. Це пояснюють тим, що в першому випадку носії заряду взаємодіють із електронейтральними цетрами, а в другому – із зарядженими. Імовірність генерації центрів забарвлення під час розпаду електронно-діркової пари різко зменшується зі зменшенням концентрації активатора, а імовірність висвітлювальної дії практично не залежить від вмісту домішки у кристалі. Зі зменшенням концентрації активатора зростає величина енергії, що витрачається на створення однієї комплементарної пари центрів забарвлення, а відповідно радіаційна чутливість кристала знижується. Неконтрольовані фонові домішки, якими є передусім ізовалентні чужорідні іони, якщо їх концентрація менша за величину с&lt;0,01 мол. %, не впливають на радіаційну чутливість кристала.Возникновение радиационной окраски в ионных кристаллах есть результатом локализации созданных радиацией свободных носителей заряда на дорадиационных точечных дефектах кристаллической решетки. С накоплением в кристаллах центров окраски происходят обратные процессы. Свободные носители заряда рекомбинируют на центрах окраски, дорадиационные дефекты возникают вновь. При длительном облучении кристаллов происходит динамическое равновесие между процессами образования центров окраски и их анигиляцией под действием рентгеновских лучей. Предложена одномерная модель ионных кристаллов, в которой получены параметры радиационной чувствительности кристаллов флюоритов и щелочно-галоидных кристаллов, легированных изовалентными примесями. Независимо от концентрации активатора в кристалле вероятность образования центров окраски при распаде электронно-дырочной пары всегда меньше вероятности их разрушения. Это объясняется тем, что в первом случае носители заряда взаимодействуют с электронейтральным центром, а во втором – с заряженным. Вероятность образования центров окраски при распаде электронно-дырочной пары сильно уменьшается с уменьшением концентрации активатора, а вероятность разрушающего действия радиации практически не зависит от содержания примеси в кристалле. С уменьшением концентрации активатора увеличивается энергия, расходуемая на создание одной комплементарной пары центров окраски, а соответственно радиационная чувствительность кристалла уменьшается. Неконтролируемые фоновые примеси, которыми есть в первую очередь изовалентные ионы, если их концентрация меньше с &lt;0,01 мл. %, не влияют на радиационную чувствительность кристалла.The occurrence of the radiation colour in ionic crystals is the result of the localization of free charge carriers, generated by radiation, on the pre-radiation point defects of the crystalline lattice. With the accumulation of the colour centres in the crystals, inverse processes take effect. The free charge carriers recombine at the colour centres, and the pre-radiation defects are restored. Prolonged irradiation of the crystals establishes a dynamic equilibrium between the processes of generation of colour centres and the illumination effect of X-rays. An one-dimensional model of ionic crystals was proposed, in which calculated were the parameters of radiation sensitivity of fluorite- and alkali-halide crystals doped with isovalent impurities. In the course of research we have found that regardless of the concentration of the activator in the crystal, the probability of the formation of colour centres at the decay of electron-hole pairs is always less than the probability of their destruction. This is explained by the fact that in the first case, the charge carriers interact with electroneutral centres, while in the second case – with charged ones. The probability of the generation of colour centres at the decay of the electron-hole pair decreases sharply with decreasing concentrations of the activator, and the probability of the illumination effect practically does not depend on the content of the impurity in the crystal. As the concentration of the activator decreases, the amount of energy consumed to create one complementary pair of colour centres increases, and, accordingly, the radiation sensitivity of the crystal drops. Uncontrolled background impurities, which are primarily isovalent foreign ions, do not affect the radiation sensitivity of the crystal provided that their concentration is less than c&lt;0.01 mol. %. Thus, as shown by the theoretical calculations, within the framework of this model, boundary concentrations of colour centres are determined depending on the concentration of the impurity, as well as the influence on the colour of the crystals of the method of hole localization adjacent to the activator has been investigated. The boundary concentration of F-centres in alkali-halide crystals is of the order of 1018 cm-3. Such a concentration of activating colour centres can be achieved if the activator concentration in the crystal has a value of the order of 0.1 mole %. Established is the dependence of the concentration of colour centres on the content of doping impurities in the crystal and on the structure of colour centres. The results of the calculations are consistent with the experimental data

Advances in understanding gray matter pathology in multiple sclerosis: Are we ready to redefine disease pathogenesis?

The purpose of this special issue in BMC Neurology is to summarize advances in our understanding of the pathological, immunological, imaging and clinical concepts of gray matter (GM) pathology in patients with multiple sclerosis (MS). Review articles by Lucchinetti and Popescu, Walker and colleagues, Hulst and colleagues and Horakova and colleagues summarize important recent advances in understanding GM damage and its implications to MS pathogenesis. They also raise a number of important new questions and outline comprehensive approaches to addressing those questions in years to come. In the last decade, the use of immunohistochemistry staining methods and more advanced imaging techniques to detect GM lesions, like double inversion recovery, contributed to a surge of studies related to cortical and subcortical GM pathology in MS. It is becoming more apparent from recent biopsy studies that subpial cortical lesions in early MS are highly inflammatory. The mechanisms responsible for triggering meningeal inflammation in MS patients are not yet elucidated, and they should be further investigated in relation to their role in initiating and perpetuating the disease process. Determining the role of antigens, environmental and genetic factors in the pathogenesis of GM involvement in MS is critical. The early involvement of cortical and subcortical GM damage in MS is very intriguing and needs to be further studied. As established in numerous cross-sectional and longitudinal studies, GM damage is a better predictor of physical disability and cognitive impairment than WM damage. Monitoring the evolution of GM damage is becoming an important marker in predicting future disease course and response to therapy in MS patients

Assessment of Colobanthus quitensis genetic polymorphism from the Argentine Islands region (maritime Antarctic) by actin, α- and γ-tubulin gene intron analysis

Colobanthus quitensis is one of the two angiosperm plant species commonly spread in the Antarctic. The species has been extensively analyzed at morphological, anatomical and physiological levels, but information regarding its genetic vari-ability remains limited. The aim of the study was to identify molecular genetic differences between C. quitensis populations in one of the Antarctic localities, the Argentine Islands region by estimating the intron length polymorphism of actin, α- and γ-tubulin genes. Samples of C. quitensis from different Antarctic natural populations were collected during the season of the 24th and previous Ukrainian Antarctic expeditions. Total DNA was isolated using the QIAGEN DNeasy Plant Mini Kit. The polymerase chain reaction was carried out with our own degenerate primers. The resulting amplicons were separated and visualized using polyacrylamide gel electrophoresis followed by silver nitrate staining. Molecular genetic analysis of natural populations of C. quitensis was performed using three DNA-marker systems based on the detection of intron length polymor-phism of actin, α- and γ-tubulin genes. A low level of genetic polymorphism of C. quitensis in the studied region by these types of markers was established. By assessing the intron length polymorphism of actin genes of the studied C. quitensis populations it was possible to establish that the populations of Skua Island had unique amplicons characteristic only for this location. This indicates the possibility of further use of the analysis of intron length polymorphism of actin genes for the study of the molecu-lar genetic diversity of the Antarctic pearlwort. At the same time, the results of analysis of the intron length polymorphism of α- and γ-tubulin genes induce selection of more specific primers, taking into account the structure of the C. quitensis genome. C. quitensis in the study region has a low level of genetic variability in intron length polymorphism of actin, α- and γ-tubulin genes. Overall, the results indicate that DNA markers based on gene structure analysis of highly conserved cytoskeletal pro-teins, namely, actin, α- and γ-tubulin, as additional sources of information, can be used for molecular genetic analysis of C. quitensis populations in the Antarctic

The future of multiple sclerosis treatments

Introduction. There are not many conditions in which the last few decades have brought such a major change in the landscape of treatments as is the case of multiple sclerosis (MS). A number of disease modifying treatments (DMTs) are presently available for the treatment of the inflammatory phase of this disabling disease; however, the need for treating neurodegeneration and halting the progression of disability is still unmet. Areas covered: In this paper we review the available information on existing and emerging DMTs and we discuss their place within the context of different treatment strategies in MS. Expert Commentary: The future of MS treatments should include the development of new treatment strategies tackling disease progression, together with a better understanding of the side-effects and the best sequential strategy of implementation of available and emerging drugs