Sex Ratio and Sexual Size Dimorphism in a Toad-headed Lizard, Phrynocephalus guinanensis

Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism (SSD) is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P. guinanensis. Our results indicated that the sex ratio of males to females was 1:2.8. Males had a lower survival rate (6%) than females (14%) across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates

Robust Optical Data Encryption by Projection-Photoaligned Polymer-Stabilized-Liquid-Crystals

The emerging Internet of Things (IoTs) invokes increasing security demands that require robust encryption or anti-counterfeiting technologies. Albeit being acknowledged as efficacious solutions in processing elaborate graphical information via multiple degrees of freedom, optical data encryption and anti-counterfeiting techniques are typically inept in delivering satisfactory performance without compromising the desired ease-of-processibility or compatibility, thus leading to the exploration of novel materials and devices that are competent. Here, a robust optical data encryption technique is demonstrated utilizing polymer-stabilized-liquid-crystals (PSLCs) combined with projection photoalignment and photopatterning methods. The PSLCs possess implicit optical patterns encoded via photoalignment, as well as explicit geometries produced via photopatterning. Furthermore, the PSLCs demonstrate improved robustness against harsh chemical environments and thermal stability, and can be directly deployed onto various rigid and flexible substrates. Based on this, it is demonstrated that single PSLC is apt to carry intricate information, or serve as exclusive watermark with both implicit features and explicit geometries. Moreover, a novel, generalized design strategy is developed, for the first time, to encode intricate and exclusive information with enhanced security by spatially programming the photoalignment patterns of a pair of cascade PSLCs, which further illustrates the promising capabilies of PSLCs in optical data encryption and anti-counterfeiting

Spatiotemporal transcriptomic atlas of mouse organogenesis using DNA nanoball-patterned arrays.

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.This work is part of the ‘‘SpatioTemporal Omics Consortium’’ (STOC) paper package. A list of STOC members is available at: http://sto-consortium.org. We would like to thank the MOTIC China Group, Rongqin Ke (Huaqiao University, Xiamen, China), Jiazuan Ni (Shenzhen University, Shenzhen, China), Wei Huang (Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China), and Jonathan S. Weissman (Whitehead Institute, Boston, USA) for their help. This work was supported by the grant of Top Ten Foundamental Research Institutes of Shenzhen, the Shenzhen Key Laboratory of Single-Cell Omics (ZDSYS20190902093613831), and the Guangdong Provincial Key Laboratory of Genome Read and Write (2017B030301011); Longqi Liu was supported by the National Natural Science Foundation of China (31900466) and Miguel A. Esteban’s laboratory at the Guangzhou Institutes of Biomedicine and Health by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA16030502), National Natural Science Foundation of China (92068106), and the Guangdong Basic and Applied Basic Research Foundation (2021B1515120075).S

Enhanced <i>T</i>_g‑Confinement Effect in Cross-Linked Polystyrene Compared to Its Linear Precursor: Roles of Fragility and Chain Architecture

The glass transition temperature (<i>T</i>_g) of cross-linked polystyrene (PS) is directly compared to that of its linear precursor polystyrene-<i>co</i>-vinyl­benzo­cyclobutene (PS–VBCB) in bulk and confined states. The VBCB units incorporated into a linear PS precursor cross-link with one another upon annealing at 250 °C. Bulk <i>T</i>_g (<i>T</i>_g,bulk) is characterized by differential scanning calorimetry (DSC) and ellipsometry, with <i>T</i>_g,bulk and <i>T</i>_g breadth increasing with increased cross-linking. The <i>T</i>_g-confinement effect is characterized by ellipsometry in supported PS–VBCB films before and after cross-linking; <i>T</i>_g decreases with decreasing nanoscale thickness in both supported linear and cross-linked polymer films. The magnitude of the confinement effect is greater in cross-linked PS compared to linear precursors; e.g., with PS-VBCB containing 8.5 mol % VBCB, <i>T</i>_g – <i>T</i>_g,bulk = −2 to −3 °C for a 23 nm thick film of linear polymer whereas <i>T</i>_g – <i>T</i>_g,bulk = −8 to −9 °C after cross-linking. The larger <i>T</i>_g reduction upon confinement in cross-linked PS is correlated with increased bulk fragility after cross-linking as measured by DSC and ellipsometry. Neat linear PS–VBCB copolymers provide an extension to lower fragility of the correlation between the <i>T</i>_g-confinement effect and bulk fragility observed previously [Evans Macromolecules 2013, 46, 6091] for neat linear polymers lacking attractive polymer–substrate interactions; i.e., the strength of the <i>T</i>_g-confinement effect increases with increasing bulk fragility. Both cross-linked PS and doped PS films deviate from the relationship for neat linear polymers, the former being weaker and the latter stronger. These results indicate that chain architecture and dopant content modify the relationship between the strength of the <i>T</i>_g-confinement effect and bulk fragility observed in many neat, linear polymers

Collaborative personalized tweet recommendation

Twitter has rapidly grown to a popular social network in recent years and provides a large number of real-time messages for users. Tweets are presented in chronological order and users scan the followees ’ timelines to find what they are interested in. However, an information overload problem has troubled many users, especially those with many followees and thousands of tweets arriving every day. In this paper, we focus on recommending useful tweets that users are really interested in personally to reduce the users ’ effort to find useful information. Many kinds of information on Twitter are available for helping recommendation, including the user’s own tweet history, retweet history and social relations between users. We propose a method of making tweet recommendations based on collaborative ranking to capture personal interests. It can also conveniently integrate the other useful contextual information. Our final method considers three major elements on Twitter: tweet topic level factors, user social relation factors and explicit features such as authority of the publisher and quality of the tweet. The experiments show that all the proposed elements are important and our method greatly outperforms several baseline methods

Comparison experiment on steel and non-steel slotted screen pipes used in coalbed methane wells

To reduce the current high completion cost for steel slotted screen pipes in coalbed methane wells and to develop low-intensity non-metal completion pipes to perform low-cost completion, this paper adopts electric survey to measure the collapsing strength and bending strength of J55 steel screen pipe and PVC non-metal screen pipe, and makes a comparative analysis of the effect of slot width and slot density on the strength of both kinds of screen pipes. The research results indicate that: the collapse of steel screen pipes mainly results from stiffness reduction or radial unstableness, showing the whole pipe deformation or the slot becoming wide or narrow at the internal or external wall along the short axis, accompanied with the tearing at the slot end-point; while the PVC screen damage mainly results from the material itself. For both steel and PVC screen pipes, the pipe's collapsing/bending strength declines with increase of the slot width and density, but the PVC screen pipes do not show such an obvious trend, making it possible to apply wider and denser slots on PVC pipes to increase the passing area. Key words: coalbed methane well, screen pipe completion, steel screen pipe, PVC screen pipe, slot width, slot density, strength, experimen

A practical and comprehensive evaluation method for series-connected battery pack models

Accurate and computationally efficient series-connected battery pack models (PMs) in new energy vehicles are extremely important for battery management. Based on a system of indexes of accuracy, adaptability, and computational complexity, this article presents a practical and comprehensive evaluation method for series-connected battery PMs, which is crucial for model selection and model-based algorithm development. Seventeen battery PMs, based on four series-connected battery pack structure models and three battery cell models, are introduced and discussed in detail. Experiments are designed and carried out to collect realistic battery test data for parameter identification and model comparisons. The estimation accuracy and computational complexity of different battery PMs are compared. Both the merits and demerits of each battery PM are thoroughly analyzed and discussed. The practical comprehensive evaluation results provide useful insights that will enable industry and academia to design more advanced battery management systems for battery packs

Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel

The process of crack propagation and tunnel failure is affected by the cross-sectional geometry of an underground tunnel. In order to quantify the effect of section shape on the process of crack propagation in deep tunnels under high ground stress conditions, a total of four physical models with two cross-sectional shapes and twelve stress levels were designed and several large-scale physical model tests were conducted. The results indicated that, when the vertical stress is 4.94 MPa, the length and depth of the cracks generated in the rock surrounding the horseshoe tunnel are about eight times that around a circular tunnel. The position where the circumferential displacement of the horseshoe tunnel begins to be stable is about two, to two and a half, times that around a circular tunnel. After the deep chamber was excavated, continuous spalling was found to occur at the foot of the horseshoe tunnel and microcracks in the surrounding rock were initially generated from the foot of the side wall and then developed upwards to form a conjugate sliding shape to the foot of the arch roof, where the cracks finally coalesced. Discontinuous spalling occurred at the midheight of the side wall of the circular tunnel after excavation, and microcracks in the surrounding rock were initially generated from the midheight of the side wall and then extended concentrically to greater depth in the rock mass surrounding the tunnel. Tensile failure mainly occurred on the surface of the side wall: shear failure mainly appeared in the surrounding rock