Maternal eating behavior is a major synchronizer of fetal and postnatal peripheral clocks in mice

Most living organisms show circadian rhythms in physiology and behavior. These oscillations are generated by endogenous circadian clocks, present in virtually all cells where they control key biological processes. To study peripheral clocks in vivo, we developed an original model, the Rev-Luc mouse to follow noninvasively and longitudinally Rev-Luc oscillations in peripheral clocks using in vivo bioluminescence imaging. We found in vitro and in vivo a robust diurnal rhythm of Rev-Luc, mainly in liver, intestine, kidney and adipose tissues. We further confirmed in vivo that Rev-Luc peripheral tissues are food-entrainable oscillators, not affected by age or sex. These data strongly support the relevance of the Rev-Luc model for circadian studies, especially to investigate in vivo the establishment and the entrainment of the rhythm throughout ontogenesis. We then showed that Rev-Luc expression develops dynamically and gradually, both in amplitude and in phase, during fetal and postnatal development. We also demonstrate for the first time that the immature peripheral circadian system of offspring in utero is mainly entrained by maternal cues from feeding regimen. The prenatal entrainment will also differentially determine the Rev-Luc expression in pups before weaning underlining the importance of the maternal chrononutrition on the circadian system entrainment of the offspring.     

Existence and Uniqueness Results for Quaternion-Valued Nonlinear Impulsive Differential Systems

This paper studies the existence and uniqueness conditions for the quaternion-valued nonlinear impulsive system. Firstly, a space of quaternion-valued piecewise functions is constructed and completeness of the space is also proved. Then by taking advantage of the Bielecki norm and fixed point theorem, existence and uniqueness criteria of quaternion-valued nonlinear impulsive system are obtained. At last, an example is given to illustrate our theoretical results.     

Re-evaluation of protein kinase CK2 pleiotropy: new insights provided by a phosphoproteomics analysis of CK2 knockout cells

CK2 denotes a ubiquitous and pleiotropic protein kinase whose holoenzyme is composed of two catalytic (α and/or α′) and two regulatory β subunits. The CK2 consensus sequence, S/T-x-x-D/E/pS/pT is present in numerous phosphosites, but it is not clear how many of these are really generated by CK2. To gain information about this issue, advantage has been taken of C2C12 cells entirely deprived of both CK2 catalytic subunits by the CRISPR/Cas9 methodology. A comparative SILAC phosphoproteomics analysis reveals that, although about 30% of the quantified phosphosites do conform to the CK2 consensus, only one-third of these are substantially reduced in the CK2α/α′^(?/?) cells, consistent with their generation by CK2. A parallel study with C2C12 cells deprived of the regulatory β subunit discloses a role of this subunit in determining CK2 targeting. We also find that phosphosites notoriously generated by CK2 are not fully abrogated in CK2α/α′^(?/?) cells, while some phosphosites unrelated to CK2 are significantly altered. Collectively taken our data allow to conclude that the phosphoproteome generated by CK2 is not as ample and rigidly pre-determined as it was believed before. They also show that the lack of CK2 promotes phosphoproteomics perturbations attributable to kinases other than CK2.     

Ciliary proteins Fap43 and Fap44 interact with each other and are essential for proper cilia and flagella beating

Cilia beating is powered by the inner and outer dynein arms (IDAs and ODAs). These multi-subunit macrocomplexes are arranged in two rows on each outer doublet along the entire cilium length, except its distal end. To generate cilia beating, the activity of ODAs and IDAs must be strictly regulated locally by interactions with the dynein arm-associated structures within each ciliary unit and coordinated globally in time and space between doublets and along the axoneme. Here, we provide evidence of a novel ciliary complex composed of two conserved WD-repeat proteins, Fap43p and Fap44p. This complex is adjacent to another WD-repeat protein, Fap57p, and most likely the two-headed inner dynein arm, IDA I1. Loss of either protein results in altered waveform, beat stroke and reduced swimming speed. The ciliary localization of Fap43p and Fap44p is interdependent in the ciliate Tetrahymena thermophila.     

A latent ability to persist: differentiation in <Emphasis Type="Italic">Toxoplasma gondii</Emphasis>

A critical factor in the transmission and pathogenesis of Toxoplasma gondii is the ability to convert from an acute disease-causing, proliferative stage (tachyzoite), to a chronic, dormant stage (bradyzoite). The conversion of the tachyzoite-containing parasitophorous vacuole membrane into the less permeable bradyzoite cyst wall allows the parasite to persist for years within the host to maximize transmissibility to both primary (felids) and secondary (virtually all other warm-blooded vertebrates) hosts. This review presents our current understanding of the latent stage, including the factors that are important in bradyzoite induction and maintenance. Also discussed are the recent studies that have begun to unravel the mechanisms behind stage switching.     

The Documentary Real: Thinking Documentary Aesthetics

In this article we consider the growing interest in recent years in the use of documentary strategies in the wold of contemporary art, film and performing arts and explore some of the central epistemological assumptions underpinning the persistent idea that the documentary should be equated with ‘non-fiction’. Following Stella Bruzzi we argue that if documentary theory maintains objectivity as the primary measure of value, it will inevitably and continuously arrive at the conclusion that the documentary genre is fundamentally flawed. Instead, we propose to move beyond the ‘realist epistemology’ of documentary theory and focus on the ‘documentary real’, i.e. the specific performativity of the reality constructed in and by the documentary genre. In the last paragraphs, we introduce the various articles that address the “documentary real” in this special issue.     

基于稳健协方差矩阵的ADS-B压制式干扰抑制

压制式干扰是广播式自动相关监视(automatic dependent surveillance broadcast, ADS-B)系统面临的最常见且最有威胁的干扰之一。提出基于稳健协方差矩阵估计的ADS-B压制式干扰抑制算法。首先,考虑了ADS-B信号的脉冲特性,将协方差矩阵的求解转化成凸优化问题。然后,利用求解凸优化问题得到的稳健协方差矩阵设计最优权矢量。最后,对观测信号进行空域滤波,完成ADS-B的压制式干扰抑制,并对抑制结果进行性能分析。提供的仿真实验结果也验证了算法的有效性,该方法不需要知道ADS-B信号来向,且在非高斯噪声情况下同样有效。