A Case of Beta-propeller Protein-associated Neurodegeneration due to a Heterozygous Deletion of WDR45

Background: Static encephalopathy of childhood with neurodegeneration in adulthood is a phenotypically distinctive, X-linked dominant subtype of neurodegeneration with brain iron accumulation (NBIA). WDR45 mutations were recently identified as causal. WDR45 encodes a beta-propeller scaffold protein with a putative role in autophagy, and the disease has been renamed beta-propeller protein-associated neurodegeneration (BPAN). Case Report: Here we describe a female patient suffering from a classical BPAN phenotype due to a novel heterozygous deletion of WDR45. An initial gene panel and Sanger sequencing approach failed to uncover the molecular defect. Based on the typical clinical and neuroimaging phenotype, quantitative polymerase chain reaction of the WDR45 coding regions was undertaken, and this showed a reduction of the gene dosage by 50% compared with controls. Discussion: An extended search for deletions should be performed in apparently WDR45-negative cases presenting with features of NBIA and should also be considered in young patients with predominant intellectual disabilities and hypertonia/parkinsonism/dystonia

Influence of Selected Modeling Parameters on Plant Segmentation Quality Using Decision Tree Classifiers

Modern precision agriculture applications increasingly rely on stable computer vision outputs. An important computer vision task is to discriminate between soil and plant pixels, which is called plant segmentation. For this task, supervised learning techniques, such as decision tree classifiers (DTC), support vector machines (SVM), or artificial neural networks (ANN) are increasing in popularity. The selection of training data is of utmost importance in these approaches as it influences the quality of the resulting models. We investigated the influence of three modeling parameters, namely proportion of plant pixels (plant cover), criteria on what pixel to choose (pixel selection), and number/type of features (input features) on the segmentation quality using DTCs. Our findings show that plant cover and, to a minor degree, input features have a significant impact on segmentation quality. We can state that the overperformance of multi-feature input decision tree classifiers over threshold-based color index methods can be explained to a high degree by the more balanced training data. Single-feature input decision tree classifiers can compete with state-of-the-art models when the same training data are provided. This study is the first step in a systematic analysis of influence parameters of such plant segmentation models

Soil greenhouse gas fluxes from a humid tropical forest and differently managed urban parkland in Singapore

Studies of soil greenhouse gas (GHG) fluxes (CO2, CH4 and N2O) from tropical soils are still scarce and the effects of urban green space management on soil GHG fluxes are poorly addressed. In order to establish reliable global GHG budgets, field measurements of soil GHG fluxes from different land uses and management practices in tropical regions are urgently needed. In this study, soil fluxes of CO2, CH4 and N2O were measured over a period of one year, from a forest and an urban parkland in Singapore. At the parkland site, two additional management practices were investigated, namely compost application to urban lawn and the replacement of lawn by legumes. The average CO2 efflux from the forest soil was 0.17 ± 0.01 g C m-2 h-1 and was 30% lower than that of the parkland soil. The forest soil was a CH4 sink (-36.03 ± 8.80 mu g C m-2 h-1), while the parkland soil was a source of CH4 (43.79 ± 9.66 mu g C m-2 h-1). Both soils were net emitters of N2O, with the forest soil releasing four times more N2O (23.23 ± 5.10 mu g N m-2 h-1) than the parkland soil (6.47 ± 2.52 mu g N m-2 h-1). During the entire observation period, compost application increased CO2eq by 30% compared with the untreated parkland soil. Shortly after compost addition, CO2 fluxes significantly increased and remained elevated until the end of the experiment. Soil CH4 emissions also increased, but the effect was small compared to CO2 (2eq). Compost amendment caused an immediate short-term peak of N2O emissions. However, after the first day, which was characterized by a heavy rain event, the compost effect on N2O production was negligible. Compared to grass cultivation, legume planting resulted in a 20% reduction of CO2eq. This study shows that conserving mature secondary forests and the cultivation of herbaceous legumes on tropical urban soils, where open lawn spaces are not required, can reduce soil GHG emissions

A Case of Beta-propeller Protein-associated Neurodegeneration due to a Heterozygous Deletion of <em>WDR45</em>

<p><strong>Background:</strong>&nbsp;Static encephalopathy of childhood with neurodegeneration in adulthood is a phenotypically distinctive, X-linked dominant subtype of neurodegeneration with brain iron accumulation (NBIA).&nbsp;<em>WDR45</em>&nbsp;mutations were recently identified as causal.&nbsp;<em>WDR45</em>&nbsp;encodes a beta-propeller scaffold protein with a putative role in autophagy, and the disease has been renamed beta-propeller protein-associated neurodegeneration (BPAN).</p><p><strong>Case Report:</strong>&nbsp;Here we describe a female patient suffering from a classical BPAN phenotype due to a novel heterozygous deletion of&nbsp;<em>WDR45</em>. An initial gene panel and Sanger sequencing approach failed to uncover the molecular defect. Based on the typical clinical and neuroimaging phenotype, quantitative polymerase chain reaction of the&nbsp;<em>WDR45</em>&nbsp;coding regions was undertaken, and this showed a reduction of the gene dosage by 50% compared with controls.</p><p><strong>Discussion:</strong>&nbsp;An extended search for deletions should be performed in apparently&nbsp;<em>WDR45-</em>negative cases presenting with features of NBIA and should also be considered in young patients with predominant intellectual disabilities and hypertonia/parkinsonism/dystonia.</p

Microbial processes and community composition in the rhizosphere of European beech – The influence of plant C exudates

Plant roots strongly influence C and N availability in the rhizosphere via rhizodeposition and uptake of nutrients. This study aimed at investigating the effect of resource availability on microbial processes and community structure in the rhizosphere. We analyzed C and N availability, as well as microbial processes and microbial community composition in rhizosphere soil of European beech and compared it to the bulk soil. Additionally, we performed a girdling experiment in order to disrupt root exudation into the soil. By this novel approach we were able to demonstrate that enhanced resource availability positively affected N mineralization and hydrolytic enzyme activities in the rhizosphere, but negatively affected nitrification rates and oxidative enzyme activities, which are involved in the degradation of soil organic matter. Both rhizosphere effects on N mineralization and oxidative enzyme activities disappeared in the girdling treatment. Microbial community structure in the rhizosphere, assessed by phospholipid fatty acid analysis, differed only slightly from bulk soil but was markedly altered by the girdling treatment, indicating additional effects of the girdling treatment beyond the reduction of root exudation. Differences in oxidative enzyme activities and nitrification rates between rhizosphere soil and bulk soil, however, suggest considerable differences in the (functional) microbial community composition

Synthesis, Morphological, and Electro-optical Characterizations of Metal/Semiconductor Nanowire Heterostructures

In this letter, we demonstrate the formation of unique Ga/GaAs/Si nanowire heterostructures, which were successfully implemented in nanoscale light-emitting devices with visible room temperature electroluminescence. Based on our recent approach for the integration of InAs/Si heterostructures into Si nanowires by ion implantation and flash lamp annealing, we developed a routine that has proven to be suitable for the monolithic integration of GaAs nanocrystallite segments into the core of silicon nanowires. The formation of a Ga segment adjacent to longer GaAs nanocrystallites resulted in Schottky-diode-like I/V characteristics with distinct electroluminescence originating from the GaAs nanocrystallite for the nanowire device operated in the reverse breakdown regime. The observed electroluminescence was ascribed to radiative band-to-band recombinations resulting in distinct emission peaks and a low contribution due to intraband transition, which were also observed under forward bias. Simulations of the obtained nanowire heterostructure confirmed the proposed impact ionization process responsible for hot carrier luminescence. This approach may enable a new route for on-chip photonic devices used for light emission or detection purposes