101 research outputs found

    Tinjauan Sosio Historis Strategi Pengembangan Kemampuan Menulis dalam Konteks Implementasi Kebijakan Penulisan Jurnal Pendidikan Tinggi

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    Surat Edaran Dikti 152/E/T/2012 telah disikapi pro dan kontra, seolah kebijakan Dikti merupakan tagihan pada sisi hilir namun melupakan fakta bahwa menulis bukan sekedar persoalan pada sisi hilir, namun merupakan persoalan hulu sampai dengan hilir yang melibatkan pengalaman, pendidikan dan latihan, dan motivasi sehingga memerlukan kajian secara komprehensif. Menulis merupakan proses mental yang dipengaruhi oleh faktor sosial historis yaitu pengalaman. Latihan, dan motivasi. Menulis bukanlah persoalan sederhana semudah membalikkan telapak tangan, namun menulis menyangkut persoalan kultural. Strategi pengembangan yang dilakukan seharusnya juga mencerminkan adanya aktualisasi ilmu pendidikan antara lain melalui; (1) pengembangan kemampuan menulis sejak dini secara tepat, (2) memberikan motivasi dengan menempatkan menulis sebagai pilihan karir prima, (3) pemerintah memberikan pelayanan primer terstandar seperti memberikan wadah terbitnya berbagai jurnal, (4) revitalisasi pengembangan minat baca, dan (5) menyediakan pendidikan dan latihan menulis yang memadai. Edaran Dikti 152/E/T/2012 harus dipandang sebagai langkah awal yang baik dan menjadi bagian koheren dari strategi pengembangan budaya menulis yang transformatif

    Negative cell cycle regulation by Calcineurin is necessary for proper beta cell regeneration in zebrafish

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    peer reviewedStimulation of pancreatic beta cell regeneration could be a therapeutic lead to treat diabetes. Unlike humans, the zebrafish can efficiently regenerate beta cells, notably from ductal pancreatic progenitors. To gain insight into the molecular pathways involved in this process, we established the transcriptomic profile of the ductal cells after beta cell ablation in the adult zebrafish. These data highlighted the protein phosphatase calcineurin as a new potential modulator of beta cell regeneration. We showed that calcineurin overexpression abolished the regenerative response, leading to glycemia dysregulation. On the opposite, calcineurin inhibition increased ductal cell proliferation and subsequent beta cell regeneration. Interestingly, the enhanced proliferation of the progenitors was paradoxically coupled with their exhaustion. This suggests that the proliferating progenitors are next entering in differentiation. Calcineurin appears as a guardian which prevents an excessive progenitor proliferation to preserve the pool of progenitors. Altogether, our findings reveal calcineurin as a key player in the balance between proliferation and differentiation to enable a proper beta cell regeneration

    Perinatal exposure to the fungicide ketoconazole alters hypothalamic control of puberty in female rats

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    IntroductionEstrogenic endocrine disrupting chemicals (EDCs) such as diethylstilbestrol (DES) are known to alter the timing of puberty onset and reproductive function in females. Accumulating evidence suggests that steroid synthesis inhibitors such as ketoconazole (KTZ) or phthalates may also affect female reproductive health, however their mode of action is poorly understood. Because hypothalamic activity is very sensitive to sex steroids, we aimed at determining whether and how EDCs with different mode of action can alter the hypothalamic transcriptome and GnRH release in female rats.DesignFemale rats were exposed to KTZ or DES during perinatal (DES 3-6-12μg/kg.d; KTZ 3-6-12mg/kg.d), pubertal or adult periods (DES 3-12-48μg/kg.d; KTZ 3-12-48mg/kg.d).ResultsEx vivo study of GnRH pulsatility revealed that perinatal exposure to the highest doses of KTZ and DES delayed maturation of GnRH secretion before puberty, whereas pubertal or adult exposure had no effect on GnRH pulsatility. Hypothalamic transcriptome, studied by RNAsequencing in the preoptic area and in the mediobasal hypothalamus, was found to be very sensitive to perinatal exposure to all doses of KTZ before puberty with effects persisting until adulthood. Bioinformatic analysis with Ingenuity Pathway Analysis predicted “Creb signaling in Neurons” and “IGF-1 signaling” among the most downregulated pathways by all doses of KTZ and DES before puberty, and “PPARg” as a common upstream regulator driving gene expression changes. Deeper screening ofRNAseq datasets indicated that a high number of genes regulating the activity of the extrinsic GnRH pulse generator were consistently affected by all the doses of DES and KTZ before puberty. Several, including MKRN3, DNMT3 or Cbx7, showed similar alterations in expression at adulthood.ConclusionnRH secretion and the hypothalamic transcriptome are highly sensitive to perinatal exposure to both DES and KTZ. The identified pathways should be exploredfurther to identify biomarkers for future testing strategies for EDC identification and when enhancing the current standard information requirements in regulation

    Combined analysis of single cell RNA-Seq and ATAC-Seq data reveals putative regulatory toggles operating in native and iPS-derived retina.

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    We report the generation and analysis of single-cell RNA-Seq data (> 38,000 cells) from native and iPSC-derived murine retina at four matched developmental stages spanning the emergence of the major retinal cell types. We combine information from temporal sampling, visualization of 3D UMAP manifolds, pseudo-time and RNA velocity analyses, to show that iPSC-derived 3D retinal aggregates broadly recapitulate the native developmental trajectories. However, we show relaxation of spatial and temporal transcriptome control, premature emergence and dominance of photoreceptor precursor cells, and susceptibility of dynamically regulated pathways and transcription factors to culture conditions in iPSC-derived retina. We generate bulk ATAC-Seq data for native and iPSC-derived murine retina identifying ~125,000 peaks. We combine single-cell RNA-Seq with ATAC-Seq information and obtain evidence that approximately half the transcription factors that are dynamically regulated during retinal development may act as repressors rather than activators. We propose that sets of activators and repressors with cell-type specific expression constitute regulatory toggles that lock cells in distinct transcriptome states underlying differentiation. We provide evidence supporting our hypothesis from the analysis of publicly available single-cell ATAC-Seq data for adult mouse retina. We identify subtle but noteworthy differences in the operation of such toggles between native and iPSC-derived retina particularly for the Etv1, Etv5, Hes1 and Zbtb7a group of transcription factors

    IL-4 induces CD22 expression to restrain the effector program of self-reactive virtual memory T cells

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    Abstract Parasitic helminths induce the production of interleukin (IL)-4 which causes the expansion of virtual memory CD8+ T cells (Tvm), a cell subset contributing to the control of viral coinfection. However, the mechanisms regulating IL-4-dependent Tvm activation and expansion during worm infection remain ill defined. We used single-cell RNA sequencing of CD8+ T cells to investigate IL-4-dependent Tvm responses upon helminth infection in mice. Gene signature analysis of CD8+ T cells identified a cell cluster marked by CD22, a canonical regulator of B cell activation, as a specific and selective surface marker of IL-4-induced Tvm cells. CD22+ Tvm were enriched for IFN-γ and granzyme A and retained a diverse TCR repertoire, while enriched in CDR3 sequences with features of self-reactivity. Deletion of CD22 expression in CD8+ T cells enhanced Tvm responses to helminth infection, indicating that this inhibitory receptor modulates Tvm responses. Thus, helminth-induced IL-4 drives the expansion and activation of self-reactive Tvm in the periphery that is counter-inhibited by CD22

    Conciliation biology: the eco-evolutionary management of permanently invaded biotic systems

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    Biotic invaders and similar anthropogenic novelties such as domesticates, transgenics, and cancers can alter ecology and evolution in environmental, agricultural, natural resource, public health, and medical systems. The resulting biological changes may either hinder or serve management objectives. For example, biological control and eradication programs are often defeated by unanticipated resistance evolution and by irreversibility of invader impacts. Moreover, eradication may be ill-advised when nonnatives introduce beneficial functions. Thus, contexts that appear to call for eradication may instead demand managed coexistence of natives with nonnatives, and yet applied biologists have not generally considered the need to manage the eco-evolutionary dynamics that commonly result from interactions of natives with nonnatives. Here, I advocate a conciliatory approach to managing systems where novel organisms cannot or should not be eradicated. Conciliatory strategies incorporate benefits of nonnatives to address many practical needs including slowing rates of resistance evolution, promoting evolution of indigenous biological control, cultivating replacement services and novel functions, and managing native–nonnative coevolution. Evolutionary links across disciplines foster cohesion essential for managing the broad impacts of novel biotic systems. Rather than signaling defeat, conciliation biology thus utilizes the predictive power of evolutionary theory to offer diverse and flexible pathways to more sustainable outcomes
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