Prevalent Exon-Intron Structural Changes in the APETALA1/FRUITFULL, SEPALLATA, AGAMOUS-LIKE6, and FLOWERING LOCUS C MADS-Box Gene Subfamilies Provide New Insights into Their Evolution

AP1/FUL, SEP, AGL6, and FLC subfamily genes play important roles in flower development. The phylogenetic relationships among them, however, have been controversial, which impedes our understanding of the origin and functional divergence of these genes. One possible reason for the controversy may be the problems caused by changes in the exon-intron structure of genes, which, according to recent studies, may generate non-homologous sites and hamper the homology-based sequence alignment. In this study, we first performed exon-by-exon alignments of these and three outgroup subfamilies (SOC1, AG, and STK). Phylogenetic trees reconstructed based on these matrices show improved resolution and better congruence with species phylogeny. In the context of these phylogenies, we traced evolutionary changes of exon-intron structures in each subfamily. We found that structural changes have occurred frequently following gene duplication and speciation events. Notably, exons 7 and 8 (if present) suffered more structural changes than others. With the knowledge of exon-intron structural changes, we generated more reasonable alignments containing all the focal subfamilies. The resulting trees showed that the SEP subfamily is sister to the monophyletic group formed by AP1/FUL and FLC subfamily genes and that the AGL6 subfamily forms a sister group to the three abovementioned subfamilies. Based on this topology, we inferred the evolutionary history of exon-intron structural changes among different subfamilies. Particularly, we found that the eighth exon originated before the divergence of AP1/FUL, FLC, SEP, and AGL6 subfamilies and degenerated in the ancestral FLC-like gene. These results provide new insights into the origin and evolution of the AP1/FUL, FLC, SEP, and AGL6 subfamilies

Fiber Bragg Grating Spectra in Graded-index Multimode Optical Fibers

peer reviewe

Highly sensitive fiber force sensor based on cascaded Fabry-Perot cavities and Vernier effect

peer reviewe

Global Retinoblastoma Presentation and Analysis by National Income Level.

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

Petal development and elaboration

Petals can be simple or elaborate, depending on whether they have complex basic structures and/or highly specialized epidermal modifications. It has been proposed that the independent origin and diversification of elaborate petals have promoted plant-animal interactions and, therefore, the evolutionary radiation of corresponding plant groups. Recent advances in floral development and evolution have greatly improved our understanding of the processes, patterns and mechanisms underlying petal elaboration. In this review, we compare the developmental processes of simple and elaborate petals, concluding that elaborate petals can be achieved through four main ways of modifications (i.e., marginal elaboration, ventral elaboration, dorsal elaboration and surface elaboration). Meanwhile, although different types of elaborate petals were made through different ways of modifications, they are all results of changes in the expression patterns of genes involved in organ polarity establishment and/or the proliferation, expansion and differentiation of cells. Deployment of existing genetic materials to a new function was also shown to be a key to the making of elaborate petals during evolution

Easy-to-Fabricate UV-Glue-Based Cascaded Fabry–Perot Fiber Sensor Probe for Temperature Measurement

In this paper, we propose an in-line fiber sensor probe based on UV-glue-assisted cascaded Fabry–Perot cavities for temperature measurement. The UV-curable adhesive in the sensing cavity plays an important role due to its high thermo-optic coefficient. We show that the temperature sensitivity depends on the optical path length difference between both cavities. We report a maximum value of 12.57 nm/°C in the range of 20 to 30 °C. This original sensor architecture features a low cost and simple structure that can be straightforwardly manufactured with readily available materials and a short production time

The morphology, molecular development and ecological function of pseudonectaries on Nigella damascena (Ranunculaceae) petals

Pseudonectaries, or false nectaries, the glistening structures that resemble nectaries or nectar droplets but do not secrete nectar, show considerable diversity and play important roles in plant-animal interactions. The morphological nature, optical features, molecular underpinnings and ecological functions of pseudonectaries, however, remain largely unclear. Here, we show that pseudonectaries of Nigella damascena (Ranunculaceae) are tiny, regional protrusions covered by tightly arranged, non-secretory polygonal epidermal cells with flat, smooth and reflective surface, and are clearly visible even under ultraviolet light and bee vision. We also show that genes associated with cell division, chloroplast development and wax formation are preferably expressed in pseudonectaries. Specifically, NidaYABB5, an abaxial gene with ectopic expression in pseudonectaries, is indispensable for pseudonectary development: knockdown of it led to complete losses of pseudonectaries. Notably, when flowers without pseudonectaries were arrayed beside those with pseudonectaries, clear differences were observed in the visiting frequency, probing time and visiting behavior of pollinators (i.e., honey bees), suggesting that pseudonectaries serve as both visual attractants and nectar guides. Interspecies interactions, including those between plants and pollinators, can involve deception. The authors characterize the molecular development of Nigella damascena pseudonectaries, and their adaptive function in attracting specific pollinators to concealed nectaries with visual cues

Mask Defect Detection by Combining Wiener Deconvolution and Illumination Optimization

In the extreme ultraviolet (EUV) lithography process, mask defect is inevitably replicated on chips hence the yield and quality of the product are directly related to the mask quality. Mask microscopy resolution is then an essential specification. In this work, a high-efficiency method for enhancing the resolution of mask defect is proposed based on illumination optimization and Wiener deconvolution. To validate this approach, we established a verification apparatus designed to achieve a theoretical resolution of 3.0 μm with visible light. Remarkably, the empirical results demonstrated that the actual resolution attained is as low as 2.5 μm, which can be extrapolated to 53 nm resolution based on the wavelength ratio to an EUV source. The verification demonstrates a significant improvement for various periodic fringes. Moreover, the augmented capability of the apparatus facilitates the identification of mask defects

Covalency competition induced active octahedral sites in spinel cobaltites for enhanced pseudocapacitive charge storage

Spinel cobaltites are widely presented as promising pseudocapacitive materials, however, a fundamental understanding of their structure-property relationship at an atomic level remains vague. Herein, their geometrical-site-dependent charge storage capability is investigated by substituting Co with inactive Zn and redox-active Mn. Experimental and theoretical analyses reveal that redox-active cations in octahedral sites contribute to enhanced capacitance, intrinsically determined by the covalency competition between tetrahedral and octahedral sites. The Zn2+ incorporation leads to increased occupancy of Co in octahedral sites and 2.9x increased capacitance at 1 A g(-1) current density, whereas the substituted Mn cations mainly sit in octahedral sites which can react with OH- upon cycling and separate on the spinel surface to reconstruct into delta-MnO2 nanosheets, leading to 4x increased capacitance at 1 A g(-1) current density with a detected K+ ion intercalation. Thus, the exposure of redox-active cations in octahedral sites and their intrinsic properties are influential in determining spinel oxides' pseudocapacitive properties. This work provides a general principle to optimize the pseudocapacitive properties of spinel cobaltites by deliberately selecting cations for substitution and controlling their distribution in octahedral/tetrahedral sites. It also offers a fundamental understanding of geometrical-site-dependent activity, and can effectively guide the development of spinel oxides for enhanced pseudocapacitance

Diversification of ranunculaceous petals in shape supports a generalized model for plant lateral organ morphogenesis and evolution.

Peltate organs, such as the prey-capturing traps of carnivorous plants and nectary-bearing petals of ranunculaceous species, are widespread in nature and have intrigued and perplexed scientists for centuries. Shifts in the expression domains of adaxial/abaxial genes have been shown to control leaf peltation in some carnivorous plants, yet the mechanisms underlying the generation of other peltate organs remain unclear. Here, we show that formation of various peltate ranunculaceous petals was also caused by shifts in the expression domains of adaxial/abaxial genes, followed by differentiated regional growth sculpting the margins and/or other parts of the organs. By inducing parameters to specify the time, position, and degree of the shifts and growth, we further propose a generalized modeling system, through which various unifacial, bifacial, and peltate organs can be simulated. These results demonstrate the existence of a hierarchical morphospace system and pave the way to understand the mechanisms underlying plant organ diversification