Loss of the retrograde motor for IFT disrupts localization of Smo to cilia and prevents the expression of both activator and repressor functions of Gli

AbstractSonic Hedgehog (Shh) signals are transduced into nuclear ratios of Gli transcriptional activator versus repressor. The initial part of this process is accomplished by Shh acting through Patched (Ptc) to regulate Smoothened (Smo) activity. The mechanisms by which Ptc regulates Smo, and Smo activity is transduced to processing of Gli proteins remain unclear. Recently, a forward genetic approach in mice identified a role for intraflagellar transport (IFT) genes in Shh signal transduction, downstream of Patched (Ptc) and Rab23. Here, we show that the retrograde motor for IFT is required in the mouse for the phenotypic expression of both Gli activator and repressor function and for effective proteolytic processing of Gli3. Furthermore, we show that the localization of Smo to primary cilia is disrupted in mutants. These data indicate that primary cilia act as specialized signal transduction organelles required for coupling Smo activity to the biochemical processing of Gli3 protein

RACK1 Is a Ribosome Scaffold Protein for β-actin mRNA/ZBP1 Complex

In neurons, specific mRNAs are transported in a translationally repressed manner along dendrites or axons by transport ribonucleic-protein complexes called RNA granules. ZBP1 is one RNA binding protein present in transport RNPs, where it transports and represses the translation of cotransported mRNAs, including β-actin mRNA. The release of β-actin mRNA from ZBP1 and its subsequent translation depends on the phosphorylation of ZBP1 by Src kinase, but little is known about how this process is regulated. Here we demonstrate that the ribosomal-associated protein RACK1, another substrate of Src, binds the β-actin mRNA/ZBP1 complex on ribosomes and contributes to the release of β-actin mRNA from ZBP1 and to its translation. We identify the Src binding and phosphorylation site Y246 on RACK1 as the critical site for the binding to the β-actin mRNA/ZBP1 complex. Based on these results we propose RACK1 as a ribosomal scaffold protein for specific mRNA-RBP complexes to tightly regulate the translation of specific mRNAs

Structural and micro-anatomical changes in vertebrae associated with idiopathic-type spinal curvature in the curveback guppy model

Background: The curveback lineage of guppy is characterized by heritable idiopathic-type spinal curvature thatdevelops during growth. Prior work has revealed several important developmental similarities to the human idiopathicscoliosis (IS) syndrome. In this study we investigate structural and histological aspects of the vertebrae that areassociated with spinal curvature in the curveback guppy and test for sexual dimorphism that might explain a femalebias for severe curve magnitudes in the population.Methods: Vertebrae were studied from whole-mount skeletal specimens of curved and non-curved adult males andfemales. A series of ratios were used to characterize structural aspects of each vertebra. A three-way analysis of variancetested for effects of sex, curvature, vertebral position along the spine, and all 2-way interactions (i.e., sex and curvature,sex and vertebra position, and vertebra position and curvature). Histological analyses were used to characterize microarchitecturalchanges in affected vertebrae and the intervertebral region.Results: In curveback, vertebrae that are associated with curvature demonstrate asymmetric shape distortion,migration of the intervertebral ligament, and vertebral thickening on the concave side of curvature. There is sexualdimorphism among curved individuals such that for several vertebrae, females have more slender vertebrae than domales. Also, in the region of the spine where lordosis typically occurs, curved and non-curved females have a reducedwidth at the middle of their vertebrae, relative to males.Conclusions: Based on similarities to human spinal curvatures and to animals with induced curves, the concaveconvexbiases described in the guppy suggest that there is a mechanical component to curve pathogenesis incurveback. Because idiopathic-type curvature in curveback is primarily a sagittal deformity, it is structurally more similarto Scheuermann kyphosis than IS. Anatomical differences between teleosts and humans make direct biomechanicalcomparisons difficult. However, study of basic biological systems involved in idiopathic-type spinal curvature incurveback may provide insight into the relationship between a predisposing aetiology, growth, and biomechanics.Further work is needed to clarify whether observed sex differences in vertebral characteristics are related to the femalebias for severe curves that is observed in the population

Conserved Role of unc-79 in Ethanol Responses in Lightweight Mutant Mice

The mechanisms by which ethanol and inhaled anesthetics influence the nervous system are poorly understood. Here we describe the positional cloning and characterization of a new mouse mutation isolated in an N-ethyl-N-nitrosourea (ENU) forward mutagenesis screen for animals with enhanced locomotor activity. This allele, Lightweight (Lwt), disrupts the homolog of the Caenorhabditis elegans (C. elegans) unc-79 gene. While Lwt/Lwt homozygotes are perinatal lethal, Lightweight heterozygotes are dramatically hypersensitive to acute ethanol exposure. Experiments in C. elegans demonstrate a conserved hypersensitivity to ethanol in unc-79 mutants and extend this observation to the related unc-80 mutant and nca-1;nca-2 double mutants. Lightweight heterozygotes also exhibit an altered response to the anesthetic isoflurane, reminiscent of unc-79 invertebrate mutant phenotypes. Consistent with our initial mapping results, Lightweight heterozygotes are mildly hyperactive when exposed to a novel environment and are smaller than wild-type animals. In addition, Lightweight heterozygotes exhibit increased food consumption yet have a leaner body composition. Interestingly, Lightweight heterozygotes voluntarily consume more ethanol than wild-type littermates. The acute hypersensitivity to and increased voluntary consumption of ethanol observed in Lightweight heterozygous mice in combination with the observed hypersensitivity to ethanol in C. elegans unc-79, unc-80, and nca-1;nca-2 double mutants suggests a novel conserved pathway that might influence alcohol-related behaviors in humans

Binding and neutralization of vascular endothelial growth factor (VEGF) and related ligands by VEGF Trap, ranibizumab and bevacizumab

Pharmacological inhibition of VEGF-A has proven to be effective in inhibiting angiogenesis and vascular leak associated with cancers and various eye diseases. However, little information is currently available on the binding kinetics and relative biological activity of various VEGF inhibitors. Therefore, we have evaluated the binding kinetics of two anti-VEGF antibodies, ranibizumab and bevacizumab, and VEGF Trap (also known as aflibercept), a novel type of soluble decoy receptor, with substantially higher affinity than conventional soluble VEGF receptors. VEGF Trap bound to all isoforms of human VEGF-A tested with subpicomolar affinity. Ranibizumab and bevacizumab also bound human VEGF-A, but with markedly lower affinity. The association rate for VEGF Trap binding to VEGF-A was orders of magnitude faster than that measured for bevacizumab and ranibizumab. Similarly, in cell-based bioassays, VEGF Trap inhibited the activation of VEGFR1 and VEGFR2, as well as VEGF-A induced calcium mobilization and migration in human endothelial cells more potently than ranibizumab or bevacizumab. Only VEGF Trap bound human PlGF and VEGF-B, and inhibited VEGFR1 activation and HUVEC migration induced by PlGF. These data differentiate VEGF Trap from ranibizumab and bevacizumab in terms of its markedly higher affinity for VEGF-A, as well as its ability to bind VEGF-B and PlGF

SOX2 Co-Occupies Distal Enhancer Elements with Distinct POU Factors in ESCs and NPCs to Specify Cell State

SOX2 is a master regulator of both pluripotent embryonic stem cells (ESCs) and multipotent neural progenitor cells (NPCs); however, we currently lack a detailed understanding of how SOX2 controls these distinct stem cell populations. Here we show by genome-wide analysis that, while SOX2 bound to a distinct set of gene promoters in ESCs and NPCs, the majority of regions coincided with unique distal enhancer elements, important cis-acting regulators of tissue-specific gene expression programs. Notably, SOX2 bound the same consensus DNA motif in both cell types, suggesting that additional factors contribute to target specificity. We found that, similar to its association with OCT4 (Pou5f1) in ESCs, the related POU family member BRN2 (Pou3f2) co-occupied a large set of putative distal enhancers with SOX2 in NPCs. Forced expression of BRN2 in ESCs led to functional recruitment of SOX2 to a subset of NPC-specific targets and to precocious differentiation toward a neural-like state. Further analysis of the bound sequences revealed differences in the distances of SOX and POU peaks in the two cell types and identified motifs for additional transcription factors. Together, these data suggest that SOX2 controls a larger network of genes than previously anticipated through binding of distal enhancers and that transitions in POU partner factors may control tissue-specific transcriptional programs. Our findings have important implications for understanding lineage specification and somatic cell reprogramming, where SOX2, OCT4, and BRN2 have been shown to be key factors

A family of true zero voltage zero current switching (ZVZCS) nonisolated bidirectional DC-DC converter with wide soft switching range

This paper proposes a true zero voltage zero current switching (ZVZCS) nonisolated bidirectional dc-dc converter with reduced component count. An auxiliary resonant network-which comprises of an inductor, capacitor, diode, and two switches-provides the zero voltage switching transitions of the main switches at turn on and turn off instants. In addition, a pair of auxiliary inductors, which act as inductive snubbers, aids the zero current switching transitions. The proposed configuration is able to provide soft commutation for the main switches for a wide range of input voltage, switching frequency, and load current variations-thus significantly improving the efficiency profile over a wide operating window. Besides, the auxiliary switches are also soft commutated, while the reverse recovery loss induced by the high side diode is eliminated. The ZVZCS soft switching operation is demonstrated by a 150 W prototype converter; it is proven consistent with the waveforms derived from the theoretical analysis. Its performance is evaluated against the standard hard-switched boost, buck, and several other leading soft switching converters published in the recent literature. The maximum full load efficiency at 100 kHz is recorded at 98.2% and 97.5% in the boost and buck modes, respectively

Electric vehicle charging using photovoltaic based microgrid for remote islands

This paper presents a real-time energy management scheme for electric vehicle (EV) charging using photovoltaic (PV) and energy storage, connected to the microgrid. The scheme is based on the heuristic rule-based strategies to optimize energy flow within microgrid. Preliminary results from the tests at Uligamu Island show that EV charging using proposed scheme is economical compared to charging from standalone generator. Using the PV as the main source for charging EVs, the burden on the microgrid is reduced significantly. It seems that this work is the first attempt to demonstrate the application of PV-EV charging from microgrid in remote island

Integrated photovoltaic-grid dc fast charging system for electric vehicle: A review of the architecture and control

The fast charger for electric vehicle (EV) is a complex system that incorporates numerous interconnected subsystems. The interactions among these subsystems require a holistic understanding of the system architecture, control, power electronics, and their overall interaction with the electrical grid system. This review paper presents important aspects of a PV-grid integrated dc fast charger—with a special focus on the charging system components, architecture, operational modes, and control. These include the interaction between the PV power source, grid electricity, energy storage unit (ESU) and power electronics for the chargers. A considerable amount of discussion is also dedicated to battery management systems (BMS) and their mutual interactions in the control processes. For the power electronics, the paper evaluates soft switching non-isolated dc-to-dc power converter topologies that can be possibly used as future EV chargers. In addition to these, a brief discussion on the impact of the PV-grid charging on the ac grid and distribution system and their remedial measures are presented. Furthermore, the challenges in regard to the vehicle to grid (V2G) concept are also described. It is envisaged that the information provided in this paper would be useful as a one-stop document for engineers, researchers and others who require information related to the dc fast charging of EV that incorporates a renewable energy source

Sustainable Wastewater Management for Underdeveloped Communities -- A Hands-On Method for Qualitative and Quantitative Analysis of Greywater

The quantity of greywater produced in urban areas of Dhaka city in Bangladesh is around 96-112 litres per capita per day which is 60%—70% of the average water supplied. This huge amount of greywater could be recycled via a separate distribution system to meet water demand for greywater toilet systems, gardening and irrigation. The quality parameters of collected greywater samples ranged for pH between 6.67 to 7.92, conductivity between 548 to 999 µS-cm-1, turbidity between 54 to 435 NTU, colour between 28 to 367 (Pt-Co Unit), BOD5 between 60 to 299 mg-L-1 and COD between 135 to 751 mg-L-1. It is estimated that an annual savings of 59 million Taka (about 728,300 USD based on $1 = 81 Taka as of 4/13/2017) could be achieved in a chemical and purification process if greywater is recycled for this community. This practice of recycling greywater is a step toward sustainable wastewater management for underdeveloped communities struggling with capital and dwindling freshwater sources