A hemophagocytic lymphohistiocytosis case with newly defined UNC13D (C.175G>C; p.Ala59Pro) mutation and a rare complication

Hemophagocytic lymphohistiocytosis (HLH) represents a severe hyperinflammatory condition with cardinal symptoms of prolonged fever, cytopenias, hepatosplenomegaly, and hemophagocytosis by activated, morphologically benign macrophages with impaired function of natural killer cells and cytotoxic T lymphocytes. A 2-month-old girl, who was admitted with fever, was diagnosed with HLH and her genetic examination revealed a newly defined mutation in the UNC13D (c.175G>C; p.Ala59Pro) gene. She was treated with dexamethasone, etoposide, and intrathecal methotrexate. During the second week of treatment, after three doses of etoposide, it was noticed that there was a necrotic plaque lesion on the soft palate. Pathologic examination of debrided material in PAS and Grocott staining revealed lots of septated hyphae, which was consistent with aspergillosis infection. Etoposide was stopped and amphotericin B treatment was given for six weeks. HLH 2004 protocol was completed to eight weeks with cyclosporine A orally. There was no patient with invasive aspergillosis infection as severe as causing palate and nasal septum perforation during HLH therapy. In immuncompromised patients, fungal infections may cause nasal septum perforation and treatment could be achieved by antifungal therapy and debridement of necrotic tissue. © 2015 Turkish Society of Hematology. All rights reserved

Training the brain to overcome the effect of aging on the human eye

Presbyopia, from the Greek for aging eye, is, like death and taxes, inevitable. Presbyopia causes near vision to degrade with age, affecting virtually everyone over the age of 50. Presbyopia has multiple negative effects on the quality of vision and the quality of life, due to limitations on daily activities – in particular, reading. In addition presbyopia results in reduced near visual acuity, reduced contrast sensitivity, and slower processing speed. Currently available solutions, such as optical corrections, are not ideal for all daily activities. Here we show that perceptual learning (repeated practice on a demanding visual task) results in improved visual performance in presbyopes, enabling them to overcome and/or delay some of the disabilities imposed by the aging eye. This improvement was achieved without changing the optical characteristics of the eye. The results suggest that the aging brain retains enough plasticity to overcome the natural biological deterioration with age

Bucolic Complexes

We introduce and investigate bucolic complexes, a common generalization of systolic complexes and of CAT(0) cubical complexes. They are defined as simply connected prism complexes satisfying some local combinatorial conditions. We study various approaches to bucolic complexes: from graph-theoretic and topological perspective, as well as from the point of view of geometric group theory. In particular, we characterize bucolic complexes by some properties of their 2-skeleta and 1-skeleta (that we call bucolic graphs), by which several known results are generalized. We also show that locally-finite bucolic complexes are contractible, and satisfy some nonpositive-curvature-like properties.Comment: 45 pages, 4 figure

Can Successful Founders Hold on to Their Seats after Going Public? The Impact of Venture Capitalists on Founder Turnover

In this study, we explore the impact of venture capitalist involvement on the relationship between a new venture's pre-IPO performance and the subsequent likelihood of founder turnover. Using new venture perspectives, and the life cycle and agency theories of the firm, we argue that owner-venture capitalists act as effective governance mechanisms to induce changes in new ventures from founder management to professional management. We argue that in the absence of venture capitalist involvement, founder turnovers occur only when the firm underperforms at the pre-IPO stage, whereas when venture capitalists are involved, the relationship between pre-IPO performance and turnover becomes U-shaped. In the presence of venture capitalist involvement, founders may be encouraged to step down even when the firm is performing well. We contribute to the entrepreneurship literature in two ways. First, we investigate how the involvement of venture capitalists changes the dynamics of founder-CEO turnover and performance in entrepreneurial firms. Secondly, we explore the role played by venture capitalists in the evolution of a firm beyond the earliest stage of its life cycle, particularly when the firm is about to transition from a private to a public entity. From the practitioner's point of view this study provides insights for the founding team, their incentives, and choices about their role in the firm they created after it goes public. In particular, if the propositions are empirically tested and confirmed, one can conclude that bringing in VCs guarantees departure for founder-CEOs

Reliability and Validity of “Parents’ Evaluation of Responsible Behaviors of 5-6 Year Old Children” Scale

This study is aimed at developing a scale (Parents’ Evaluation of Responsible Behaviors Of 5-6 Year Old Children) for measuring parents’ evaluation of their 5-6 year-old children’s responsible behaviors . The construct validity of the scale was tested by Factor Analysis. Factor analysis determined that the scale can be clustered under 10 factors. Item total correlations were calculated and independent samples t-test was conducted in order to determine the presence of a meaningful difference between the top and the bottom %27 groups. The reliabilities of the scale and their subscales were analysed by using Cronbach Alpha technique. Cronbach Alpha of the whole scale is 0, 92. And cronbach alpha analysis of the subscales were also so high. Also split half and test-retest reliability analyses were done. 1st Section reliability was found as Alfa: 0, 83 and 2nd Section reliability as Alfa: 0, 90.The results showed that the scale had good psychometric properties and thus could be used to assess the responsibility behaviors of 5-6 year olds

AUTOMATIC EXTRACTION OF SURFACE DYNAMICS USING GOOGLE EARTH ENGINE FOR UNDERSTANDING DROUGHT PHENOMENON

Atmospheric drought due to meteorological events occurring out of seasonal norms, and consequent droughts in agriculture and wetlands cause great damage to the ecological balance. The initial effects of this situation appear on a local scale, while the aftereffects, which last for years, appear on a global scale. Monitoring and detecting drought with remote sensing technologies can contribute to the management of water resources and forest areas and enable many measures to be taken to reduce the effects of drought. Within the scope of this study, a system that automatically performs the extraction of different drought parameters depending on years has been developed. Işıklı Lake was selected as the study area and the change of water areas over the years has been extracted from satellite images. With the system developed on the Google Earth Engine platform, different parameters were analyzed over a 13-year period and their consistency was tested. As a result, it is seen that the water areas in the lake decreased by 30% between 2010 and 2022. Likewise, the systematic decrease in the parameters, especially in 2015 and afterward, indicates the drought in the region. With the proposed automatic system, it is thought that early precautions can be taken for drought scenarios that may occur in larger-scale regions

The spatial range of peripheral collinear facilitation

Contrast detection thresholds for a central Gabor patch (target) can be modulated by the presence of co-oriented and collinear high contrast Gabors flankers. In foveal vision collinear facilitation can be observed for target-to-flankers relative distances beyond two times the wavelength (λ) of the Gabor's carrier, while for shorter relative distances (<2λ) there is suppression. These modulatory influences seem to disappear after 12λ. In this study, we measured contrast detection thresholds for different spatial frequencies (1, 4 and 6 cpd) and target-to-flankers relative distances ranging from 6 to 16λ, but with collinear configurations presented in near periphery at 4° of eccentricity. Results showed that in near periphery collinear facilitation extends beyond 12λ for the higher spatial frequencies tested (4 and 6 cpd), while it decays already at 10λ for the lowest spatial frequency used (i.e., 1 cpd). In addition, we found that increasing the spatial frequency the peak of collinear facilitation shifts towards larger target-to-flankers relative distances (expressed as multiples of the stimulus wavelength), an effect never reported neither for near peripheral nor for central vision. The results suggest that the peak and the spatial extent of collinear facilitation in near periphery depend on the spatial frequency of the stimuli used

Studies on Parameters Influencing the Performance of Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) in Detecting Prunus Necrotic Ringpot Virus (PNRSV)

In order to have a more detailed understanding of the various factors influencing a reverse transcriptase polymerase chain reaction (RT-PCR), a number of important parameters such as Mg+2, primer, enzyme concentration and others were optimized for the detection of Prunus necrotic ringspot virus (PNRSV). Using a PNRSV isolate with a pair of primers, complementary DNA of viral genome as template, and an appropriate enzyme together with magnesium chloride, the following optimal conditions were identified: primer concentration between 0.2 and 0.0002 pmol µl-1 and 0.06–2 units µl-1 for Taq DNA polymerase enzyme for a 50 µl reaction volume when other parameters were optimum; magnesium chloride concentration less than 2.5 mM; dNTP concentration between 1 and 10 mM. The optimum cDNA amount should be ~360 ng for a 50 µl reaction mixture. When these optimized concentrations and/or values of the main PCR parameters were brought together for a new RT-PCR, a clear and a reliable PNRSV detection having no background was performed from both growth-chamber and field-grown PNRSV-infected plants