Search

STUDY QUESTION Is the vertebrate protein Dead end (DND1) a causative factor for human infertility and can novel in vivo assays in zebrafish help in evaluating this? SUMMARY ANSWER Combining patient genetic data with functional in vivo assays in zebrafish reveals a possible role for DND1 in human male fertility. WHAT IS KNOWN ALREADY About 7% of the male population is affected by infertility but linking specific gene variants to the disease is challenging. The function of the DND1 protein was shown to be critical for germ cell development in several model organisms but a reliable and cost-effective method for evaluating the activity of the protein in the context of human male infertility is still missing. STUDY DESIGN, SIZE, DURATION Exome data from 1305 men included in the Male Reproductive Genomics cohort were examined in this study. A total of 1114 of the patients showed severely impaired spermatogenesis but were otherwise healthy. Eighty-five men with intact spermatogenesis were included in the study as controls. PARTICIPANTS/MATERIALS, SETTING, METHODS We screened the human exome data for rare, stop-gain, frameshift, splice site, as well as missense variants in DND1. The results were validated by Sanger sequencing. Immunohistochemical techniques and, when possible, segregation analyses were performed for patients with identified DND1 variants. The amino acid exchange in the human variant was mimicked at the corresponding site of the zebrafish protein. Using different aspects of germline development in live zebrafish embryos as biological assays, we examined the activity level of these DND1 protein variants. MAIN RESULTS AND THE ROLE OF CHANCE In human exome sequencing data, we identified four heterozygous variants in DND1 (three missense and one frameshift variant) in five unrelated patients. The function of all of the variants was examined in the zebrafish and one of those was studied in more depth in this model. We demonstrate the use of zebrafish assays as a rapid and effective biological readout for evaluating the possible impact of multiple gene variants on male fertility. This in vivo approach allowed us to assess the direct impact of the variants on germ cell function in the context of the native germline. Focusing on the DND1 gene, we find that zebrafish germ cells, expressing orthologs of DND1 variants identified in infertile men, failed to arrive correctly at the position where the gonad develops and exhibited defects in cell fate maintenance. Importantly, our analysis facilitated the evaluation of single nucleotide variants, whose impact on protein function is difficult to predict, and allowed us to distinguish variants that do not affect the protein's activity from those that strongly reduce it and could thus potentially be the primary cause for the pathological condition. These aberrations in germline development resemble the testicular phenotype of azoospermic patients. LIMITATIONS, REASONS FOR CAUTION The pipeline we present requires access to zebrafish embryos and to basic imaging equipment. The notion that the activity of the protein in the zebrafish-based assays is relevant for the human homolog is well supported by previous knowledge. Nevertheless, the human protein may differ in some respects from its homologue in zebrafish. Thus, the assay should be considered only one of the parameters used in defining DND1 variants as causative or non-causative for infertility. WIDER IMPLICATIONS OF THE FINDINGS Using DND1 as an example, we have shown that the approach described in this study, relying on bridging between clinical findings and fundamental cell biology, can help to establish links between novel human disease candidate genes and fertility. In particular, the power of the approach we developed is manifested by the fact that it allows the identification of DND1 variants that arose de novo. The strategy presented here can be applied to different genes in other disease contexts. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by the German Research Foundation, Clinical Research Unit, CRU326 'Male Germ Cells'. There are no competing interests. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

The essay tends to evaluate the surveillance mechanisms regarding the social status of women during the reign of the Pahlavi dynasty and follows its representation in Dead End by Parviz Sayyad as a critical cinematic work. Reaching this objective, initially, the concepts of visibility and invisibility are studied as two main principles in the status of prisoner and guard of the Panopticon idea. Ideas of visibility and invisibility are investigated regarding women's situation in modern Iran in order to reach an analysis about panopticon function applied by the Pahlavi government on Iranian women. Eventually, concentrating on Dead End, panopticon attitude toward the female protagonist in the film is studied to discover latent impalpable mechanisms of power (SAVAK's agent). The survey reveals how the Pahlavi government defines a woman, who has become visible through surveillance policies, in the panopticon discipline structure and turns her to a deceived object for the government's security aims. [ABSTRACT FROM AUTHOR]

This study sought to explore casual workers' posterior likelihood of being offered a permanent position at a multinational company in Zimbabwe. The study used a qualitative research approach. Data from sixteen participants who had worked for the multinational company in Zimbabwe for at least seven months were gathered using semi-structured interviews. The research found that a majority of casual work at the case multinational company in Zimbabwe see casual work as a trap than a bridge to more stable and secure positions. The three main factors identified by most of the research participants which makes casual work a trap were employer's flexibility strategy, limited training opportunities and vertical immobility. Nonetheless, a few casual workers claimed that casual employment gives them the chance to showcase their abilities and acquire jobspecific skills they need to secure full-time jobs. Hence, as it is, casual work at the case multinational company in Zimbabwe is more of a dead end than a stepping-stone to fulltime positions. The current study recommends that the case transnational firm in Zimbabwe should offer more secure contracts to some of its casual workers when there is fulltime vacancy. [ABSTRACT FROM AUTHOR]

Transgenic technology and selective breeding have great potential for the genetic breeding in both edible fish and ornamental fish. The development of infertility control technologies in transgenic fish and farmed fish is the critical issue to prevent the gene flow with wild relatives. In this study, we report the genome editing of the dead end (dnd1) gene in the zebrafish model, using the CRISPR/Cas9 technology to achieve a loss-of-function mutation in both wild-type zebrafish and transgenic fluorescent zebrafish to develop complete infertility control technology of farmed fish and transgenic fish. We effectively performed targeted mutagenesis in the dnd1 gene of zebrafish with a single gRNA, which resulted in a small deletion (-7 bp) or insertion (+41 bp) in exon 2, leading to a nullmutation. Heterozygotes and homozygotes of dnd1- knockout zebrafish were both selected by genotyping in the F1 and F2 generations. Based on a comparison of histological sections of the gonads between wild-type, heterozygous, and homozygous dnd1 zebrafish mutants, the dnd1 homozygous mutation (aa) resulted in the loss of germ cells. Still, there was no difference between the wild-type (AA) and dnd1 heterozygous (Aa) zebrafish. The homozygous dnd1 mutants of adult zebrafish and transgenic fluorescent zebrafish became all male, which had normal courtship behavior to induce wild-type female zebrafish spawning. However, they both had no sperm to fertilize the spawned eggs fromwild-type females. Thus, all the unfertilized eggs died within 10 h. The targeted mutagenesis of the dnd1 gene using the CRISPR/Cas9 technology is stably heritable by crossing of fertile heterozygous mutants to obtain sterile homozygous mutants. It can be applied in the infertility control of transgenic fluorescent fish and genetically improved farmed fish by selective breeding to promote ecologically responsible aquaculture. [ABSTRACT FROM AUTHOR]

Keywords: Dead end; Pacific bluefin tuna; Primordial germ cell; Sterile; Thunnus orientalis EN Dead end Pacific bluefin tuna Primordial germ cell Sterile Thunnus orientalis 3872 3876 5 06/14/22 20220701 NES 220701 The I dead-end i ( I dnd i ) gene was first identified in zebrafish, I Danio rerio i , as a germ plasm component encoding an RNA-binding protein (Weidinger et al., 2003). To examine germ cell deficiency in addition to observations by GFP labeling, we conducted whole-mount immunostaining using anti-germ cell marker Vasa antibodies, as described previously (Hayashida, Higuchi, Hashimoto, et al., 2021), and histological analysis. In fact, inhibiting I dnd i expression causes faulty migration and ablation of zebrafish PGCs, resulting in germ cell deficiency (Weidinger et al., 2003). The zebrafish Dnd protein binds to 3' untranslated regions (3'UTR) of germline RNAs, such as I nanos i mRNAs, thereby protecting them against microRNA-mediated degradation, so they can contribute to the migration and survival of primordial germ cells (PGCs) (Kedde et al., 2007; Weidinger et al., 2003). [Extracted from the article]

Abstract Background Due to the complexity of microbial communities, de novo assembly on next generation sequencing data is commonly unable to produce complete microbial genomes. Metagenome assembly binning becomes an essential step that could group the fragmented contigs into clusters to represent microbial genomes based on contigs’ nucleotide compositions and read depths. These features work well on the long contigs, but are not stable for the short ones. Contigs can be linked by sequence overlap (assembly graph) or by the paired-end reads aligned to them (PE graph), where the linked contigs have high chance to be derived from the same clusters. Results We developed METAMVGL, a multi-view graph-based metagenomic contig binning algorithm by integrating both assembly and PE graphs. It could strikingly rescue the short contigs and correct the binning errors from dead ends. METAMVGL learns the two graphs’ weights automatically and predicts the contig labels in a uniform multi-view label propagation framework. In experiments, we observed METAMVGL made use of significantly more high-confidence edges from the combined graph and linked dead ends to the main graph. It also outperformed many state-of-the-art contig binning algorithms, including MaxBin2, MetaBAT2, MyCC, CONCOCT, SolidBin and GraphBin on the metagenomic sequencing data from simulation, two mock communities and Sharon infant fecal samples. Conclusions Our findings demonstrate METAMVGL outstandingly improves the short contig binning and outperforms the other existing contig binning tools on the metagenomic sequencing data from simulation, mock communities and infant fecal samples.

The dead end gene has been identified as a essential factor for Primordial germ cells (PGCs) migration and survival in many species, but its role in Monopterus albus is unclear. In order to clarify the function of dead end gene in M.albus PGCs migration and survival, we first characterized the expression profile of M.albus dead end (Madnd) in developing embryos and various tissues. qRT-PCR revealed that Madnd transcripts were exclusively detected in gonad, including ovary, testis and ovotestis.Embryos injected with a Madnd morpholino (Madnd-MO) exhibited down-regulation of the vasa gene. Furthermore, the GFP signal show the PGCs migration in control group were injected with GFP-nanos3 3′-UTR mRNA for visualization, as described in a previous study, yet it was disappeared after embryos injected with Madnd-MO.Finally, we characterized the genomics sequence of the Madnd gene and designed five gRNAs for genome editing. Three gRNAs were selected for microinjection according to the results of in vitro tests. gRNAd1 was used for microinjection with the Cas9 protein and was confirmed to be effective. Our analysis in this study suggested that Madnd play a key role in PGCs migration and survival in M. albus. These data provide the basis for the production of fast-growing and reproductively M.albus sterile. • Expression profile of Madnd gene in developing embryos and tissues was reported. • Madnd was crucial for PGCs migration and survival in embryos. • Genome editing technology was developed for the further studies in the future. [ABSTRACT FROM AUTHOR]

A 3D Computational Fluid Dynamics (CFD) model of an exhaust manifold with and without a dead end has been developed to investigate the impacts of its geometry on the flow structure and the pressure distribution within the manifold. The model differs from previously studied models principally for its ability to approach the realistic operating principle of an engine as the modelled exhaust valves of the investigated engine open and close according to the firing order. The experimental results of an exhaust manifold without a dead end has been used to validate the CFD model through the pressure distribution and the flow structure. The outcomes demonstrated that the developed CFD model concurred well with the experimental data. The effects of the dead end on the exhaust manifold were then investigated using the validated CFD model. The study has revealed that the addition of a dead end (i) provides a smoother pressure distribution inside the manifold and increase in the efficiency of the turbocharger and (ii) decreases the pressure inside of the interconnection pipes of cylinders while the exhaust gas discharges. Moreover, the results disclose a smoother discharge of exhaust gases leading to a more effective sweeping of the exhaust gas thorough the cylinder without causing any exhaust backpressure. Furthermore, the dead end reduces the turbulence kinetic energy at the blind end of the exhaust manifold resulting in a decrease of pressure loss within. The abovementioned findings regarding to the flow structure and the pressure distribution within the exhaust manifold improve the efficiency of the engine. [ABSTRACT FROM AUTHOR]

Background: Due to the complexity of microbial communities, de novo assembly on next generation sequencing data is commonly unable to produce complete microbial genomes. Metagenome assembly binning becomes an essential step that could group the fragmented contigs into clusters to represent microbial genomes based on contigs' nucleotide compositions and read depths. These features work well on the long contigs, but are not stable for the short ones. Contigs can be linked by sequence overlap (assembly graph) or by the paired-end reads aligned to them (PE graph), where the linked contigs have high chance to be derived from the same clusters. Results: We developed METAMVGL, a multi-view graph-based metagenomic contig binning algorithm by integrating both assembly and PE graphs. It could strikingly rescue the short contigs and correct the binning errors from dead ends. METAMVGL learns the two graphs' weights automatically and predicts the contig labels in a uniform multi-view label propagation framework. In experiments, we observed METAMVGL made use of significantly more high-confidence edges from the combined graph and linked dead ends to the main graph. It also outperformed many state-of-the-art contig binning algorithms, including MaxBin2, MetaBAT2, MyCC, CONCOCT, SolidBin and GraphBin on the metagenomic sequencing data from simulation, two mock communities and Sharon infant fecal samples. Conclusions: Our findings demonstrate METAMVGL outstandingly improves the short contig binning and outperforms the other existing contig binning tools on the metagenomic sequencing data from simulation, mock communities and infant fecal samples. [ABSTRACT FROM AUTHOR]

The author, starting from personal cues, hypothesizes secret resonances between Jung and Winnicott, so different but linked by a deep search. Starting from Jung's first dream, recorded in his diary Memoirs, Dreams, Reflections, and from a poem by Winnicott, The Tree, the author ventures into open questions about Jung's position as described in the Memoirs and Winnicott's position in his review of Jung's diary. The exchanges of letters between Winnicott and Fordham are also considered. The author proposes a deeper and more emotional reading of a common departure of the two masters from the fact of having had depressed mothers and the process of each of them starting from this situation so significant for both. The two differ immensely, but it seems to the author that Jung may have somehow "helped" Winnicott to face and recognize the presence of a unitary continuum of being, on which Winnicott reflected in his last works. [ABSTRACT FROM AUTHOR]

In many organisms, primordial germ cells (PGCs) are specified at a different location than where the gonad forms, meaning that PGCs must migrate toward the gonad within the early developing embryo. Following species-specific paths, PGCs can be passively carried by surrounding tissues and also perform active migration. When PGCs actively migrate through and along a variety of embryonic structures in different organisms, they adopt an ancestral robust migration mode termed "amoeboid motility", which allows cells to migrate within diverse environments. In this review, we discuss the possible significance of the PGC migration process in facilitating the evolution of animal body shape. In addition, we summarize the latest findings relevant for the molecular and cellular mechanisms controlling the movement and the directed migration of PGCs in different species. [ABSTRACT FROM AUTHOR]

dnd is a germline-specific maternal RNA expressed in various vertebrate classes, which encodes an RNA-binding protein that is essential for PGC migration. The purpose of this study is fundamental research about starry flounder dnd gene for germ cell marker development. In this study, we cloned and analyzed the expression levels of Platichthys stellatus dead end (psdnd) in various tissues and embryonic stages. The psdnd gene was isolated from starry flounder ovaries, cloned into a pGEM-t vector, and sequenced. Full-length of psdnd cDNA was 1495 bp long, encoding 395 amino acids. psdnd expression levels were investigated by real-time polymerase chain reaction (qRT-PCR) in various tissues and embryo developmental stages. psdnd transcripts were detected in the testes and ovaries, but not in somatic tissues. Embryonic psdnd expression levels were higher during early embryo development stages than during late embryogenesis; psdnd expression was highest at the 1 cell stage, then gradually decreased throughout the subsequent developmental stages. The spatial expression pattern was analyzed by whole-mount in situ hybridization (WISH). The psdnd transcripts migration pattern was similar with zebrafish (Danio rerio). Our results suggest that psdnd may function as a germ cell-specific marker.

This paper addresses an operating room planning problem with surgical demands from both the elective patients and the non-elective ones. A dynamic waiting list is established to prioritize and manage the patients according to their urgency levels and waiting times. In every decision period, sequential decisions are taken by selecting high-priority patients from the waiting list to be scheduled. With consideration of random arrivals of new patients and uncertain surgery durations, the studied problem is formulated as a novel Markov decision process model with dead ends. The objective is to optimize a combinatorial cost function involving patient waiting times and operating room over-utilizations. Considering that the conventional dynamic programming algorithms have difficulties in coping with large-scale problems, we apply several adapted real-time dynamic programming algorithms to solve the proposed model. In numerical experiments, we firstly apply different algorithms to solve the same instance and compare the computational efficiencies. Then, to evaluate the effects of dead ends on the policy and the computation, we conduct simulations for multiple instances with the same problem scale but different dead ends. Experimental results indicate that incorporating dead ends into the model helps to significantly shorten the patient waiting times and improve the computational efficiency. [ABSTRACT FROM AUTHOR]

In rice field eel (Monopterus albus), germ cell development in the developing gonad has been revealed in detail. However, it is unclear how primordial germ cells (PGCs) migrate to the somatic part of the gonad (genital ridge). This study visualized PGC migration by injecting a chimeric mRNA containing a fluorescent protein fused to the 3′ untranslated region (3′UTR) of three different genes, nanos3 of zebrafish (Danio rerio) and dead end (dnd) and vasa of rice field eel. The mRNAs were injected either alone or in pairs into embryos at the one-cell stage. The results showed that mRNAs containing nanos3 and dnd 3′UTRs labeled PGCs over a wider time frame than those containing vasa 3′UTR, suggesting that nanos3 and dnd 3′UTRs are suitable for visualizing PGCs in rice field eel. Using this direct visualization method, the normal migration route of PGCs was observed from the 50%-epiboly stage to hatching stage for the first time, and the ectopic PGCs were also visualized during this period in rice field eel. These findings extend our knowledge of germ cell development, and lay a foundation for further research on the relationship between PGCs and sex differentiation, and on incubation conditions for embryos in rice field eel. Unlabelled Image • A chimeric mRNA with nanos3 or dead end 3′UTR is suitable for visualizing PGCs in rice field eel embryos. • Reveling normal migration route of PGCs in live rice field eel embryos. • Labeling ectopic PGCs in rice field eel embryos. [ABSTRACT FROM AUTHOR]

Copyright of Special Oil & Gas Reservoirs is the property of Special Oil & Gas Reservoirs Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Germ granules, condensates of phase-separated RNA and protein, are organelles that are essential for germline development in different organisms. The patterning of the granules and their relevance for germ cell fate are not fully understood. Combining three-dimensional in vivo structural and functional analyses, we study the dynamic spatial organization of molecules within zebrafish germ granules. We find that the localization of RNA molecules to the periphery of the granules, where ribosomes are localized, depends on translational activity at this location. In addition, we find that the vertebrate-specific Dead end (Dnd1) protein is essential for nanos3 RNA localization at the condensates' periphery. Accordingly, in the absence of Dnd1, or when translation is inhibited, nanos3 RNA translocates into the granule interior, away from the ribosomes, a process that is correlated with the loss of germ cell fate. These findings highlight the relevance of sub-granule compartmentalization for post-transcriptional control and its importance for preserving germ cell totipotency. [Display omitted] • The border of phase-separated germ granules is enriched with ribosomes • The presence of mRNAs at the granule periphery depends on their translational activity • Localization of nanos3 mRNA to the granule border requires Dnd1 function • Inhibition of nanos3 RNA translation leads to the loss of germ cell fate Westerich et al. study the distribution of RNA molecules within phase-separated organelles. They find that the presence of mRNAs at the periphery of germ cell granules requires RNA translation and interaction with specific RNA-binding proteins, and they show that mislocalization of RNAs is correlated with loss of germ cell fate. [ABSTRACT FROM AUTHOR]

ABSTRACT: This paper aim to evaluate the ultrafiltration (UF) process for constituents recovery from whey. Sequences of factorial designs were performed by varying temperature (5 to 40°C) and pressure (1 to 3 bar), to maximize the proteins concentration using membrane of 100kDa in dead end system. Based on the best result new experiments were performed with membrane of 50kDa and 10kDa. With the membrane of 50 the protein retention was about 3 times higher than the membrane of 100kDa. The concentrated obtained by UF membrane of 10kDa, 10°C and 2 bar in laboratory scale showed a mean protein retention of 80 %, greater protein solubility, emulsion stability and the identification of β-lactoglobulins (18.3 kDa) and α-lactalbumin fractions (14.2kDa). Therefore, the use of membrane of 100 and 50kDa are became a industrially recommendable alternatives to concentration of whey proteins, and/or as a previous step to the fractionation of whey constituents using membrane ≤10kDa, aiming at future applications in different areas (food, pharmaceutical, chemical, etc.).

Copyright of Journal of International Social Research is the property of Journal of International Social Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gas purging is an effective method to remove the accumulated nitrogen and liquid water during the dead-end operation of polymer electrode membrane fuel cell (PEMFC). The effect of the operation pressure on the degradation characteristic of single cell is investigated under continuous gas purging cycles. Various diagnostic techniques including electrochemical characterization, physicochemical properties, and microstructure of the membrane electrode assembly (MEA) are applied to characterize the performance of the assembled single cells. After 1000 purging cycles, the single cell exhibits an obvious performance degradation, which can be proven from the change of the electrochemical surface area (ECSA), contact angle, cracks on the membrane and membrane thickness. The single cell with a relatively low oxygen pressure of 50 kPa has serious performance degradation. Comparatively, the assembled PEMFC has an enhanced durability with a high oxygen pressure of 200 kPa during the purging cycles under dead-ended operation mode. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc networks (VANETs) have attracted much research attentions in the recent years. Although there are many outstanding solutions of geographic routing designed for the VANETs, only one or two features of the VANETs have been specifically utilized in each of the proposed solutions. In this paper, we propose a novel adaptive fuzzy multiple attribute decision routing (AFMADR) scheme, by which a packet carrier is supposed to be a decision maker in the selection of a target for the next hop transmission with more factors to be considered. The AFMADR scheme consists of four steps. Firstly, the candidate vehicles are characterized by four attributes including the distance, the direction, the road density, and the location to obtain a fuzzy attribute score of each attribute. Secondly, according to the real-time conditions of the candidates' attributes, weights of attributes will be calculated by the proposed adaptive weight algorithm, which makes the AFMADR scheme more scalable and robust in different VANET scenarios. Then, a fuzzy performance score will be produced for each candidate based on the fuzzy attribute score and their real-time weights. Lastly, a route decision is made by choosing a candidate with the highest performance score as the target for the next hop transmission. We carry out simulation experiments to compare the performance of the AFMADR scheme with the existing well-known geographic routing protocols for the VANETs. The simulation results demonstrate that the proposed AFMADR scheme can achieve the best performance in terms of the highest delivery ratio and the lowest delivery delay with a reasonable number of hops among all protocols in all the simulation scenarios. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A 6 kW proton exchange membrane fuel cell system, operating in self-humidified conditions, was characterized in two anode operative modes: dead-end and flow through with exhaust recirculation. The anode sub-system was specifically designed in order to adjust the level of recycled anodic stream. The role of anode purge frequency, anode recirculation level and air stoichiometric ratio was analysed in the power range 1–5 kW. The aim of this study was to define management strategies to assure efficient and reliable cell performance during steady-state, warm-up and load variation phases. The results evidenced the combined effect of hydrogen purge, air flow rate impulse, and recycled anodic stream on individual cell performance recovery when unstable working conditions were detected during system start-up and load variations. [ABSTRACT FROM AUTHOR]