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Let the \emph{double hyperbolic space} $\mathbb{DH}^n$, proposed in this paper as an extension of the hyperbolic space $\mathbb{H}^n$, contain a two-sheeted hyperboloid with the two sheets connected to each other along the boundary at infinity. We propose to extend the volume of convex polytopes in $\mathbb{H}^n$ to polytopes in $\mathbb{DH}^n$, where the volume is invariant under isometry but can possibly be complex valued. We show that the total volume of $\mathbb{DH}^n$ is equal to $i^n V_n(\mathbb{S}^n)$ for both even and odd dimensions, and prove a Schl\"{a}fli differential formula (\SDF{}) for $\mathbb{DH}^n$. For $n$ odd, the volume of a polytope in $\mathbb{DH}^n$ is shown to be completely determined by its intersection with $\partial\mathbb{H}^n$ and induces a new intrinsic \emph{volume} on $\partial\mathbb{H}^n$ that is invariant under M\"{o}bius transformations., Comment: 38 pages, 9 figures. Sections of "Renormalized volume of hyperbolic manifold" and "De Sitter space" are removed. To appear in Beitr\"age zur Algebra und Geometrie / Contributions to Algebra and Geometry

Purpose The purpose of this study is to conduct a systematic review to understand state-of-art research related to learning preferences from the aspects of impacts, influential factors and evaluation methods. Design/methodology/approach This paper uses the systematic synthesis method to provide state-of-the-art knowledge on learning preference research by summarizing published studies in major databases and attempting to aggregate and reconcile the scientific results from the individual studies. The findings summarize aggregated research efforts and improve the quality of future research. Findings After analyzing existing literature, this study proposed three possible research directions in the future. First, researchers might focus on how to use the real-time tracking mechanism to further understand other impacts of learning preferences within the learning environments. Second, existing studies mainly focused on the influence of singular factors on learning preferences. The joint effects of multiple factors should be an important topic for future research. Finally, integrated algorithms might become the most popular evaluation method of learning preference in the era of smart learning environments. Research limitations/implications This review used the search results generated by Google Scholar and Web of Science databases. There might be published papers available in other databases that have not been taken into account. Originality/value The research summarizes the state-of-art research related to learning preferences. This paper is one of the first to discuss the development of learning preference research in smart learning environments.

The Xinjiang region in northwest China is a historically important geographical passage between East and West Eurasia. By sequencing 201 ancient genomes from 39 archaeological sites, we clarify the complex demographic history of this region. Bronze Age Xinjiang populations are characterized by four major ancestries related to Early Bronze Age cultures from the central and eastern Steppe, Central Asian, and Tarim Basin regions. Admixtures between Middle and Late Bronze Age Steppe cultures continued during the Late Bronze and Iron Ages, along with an inflow of East and Central Asian ancestry. Historical era populations show similar admixed and diverse ancestries as those of present-day Xinjiang populations. These results document the influence that East and West Eurasian populations have had over time in the different regions of Xinjiang.

A genetic history of China The history of human movements into and within China has been difficult to determine solely from archaeological investigations or genetic studies of contemporary peoples. Yang et al. sequenced DNA from 26 individuals from 9500 to 300 years ago from locations within China. Analyses of these individuals, along with previously sequenced ancient individuals and present-day genomes representing global populations, show a split between ancient humans in northern and southern China. Neolithic northern Chinese individuals are closest to modern-day East Asians, whereas ancient individuals from southern China are most closely related to modern-day Southeast Asians and show an affinity to modern-day Austronesian populations. These results indicate that there was a southward movement and admixture of peoples during the Neolithic that gave rise to modern-day populations in East Asia. Science this issue p. 282

Molar enamel thickness and distribution pattern inform on the functional and dietary adaptation of extant and fossil primates. However, no systematic analysis of enamel thickness has been conducted...

The ancestral homeland of Australian dingoes and Pacific dogs is proposed to be in South China. However, the location and timing of their dispersal and relationship to dog domestication is unclear. Here, we sequenced 7,000- to 2,000-year-old complete mitochondrial DNA (mtDNA) genomes of 27 ancient canids (one gray wolf and 26 domestic dogs) from the Yellow River and Yangtze River basins (YYRB). These are the first complete ancient mtDNA of Chinese dogs from the cradle of early Chinese civilization. We found that most ancient dogs (18/26) belong to the haplogroup A1b lineage that is found in high frequency in present-day Australian dingoes and precolonial Pacific Island dogs but low frequency in present-day China. Particularly, a 7,000-year-old dog from the Tianluoshan site in Zhejiang province possesses a haplotype basal to the entire haplogroup A1b lineage. We propose that A1b lineage dogs were once widely distributed in the YYRB area. Following their dispersal to South China, and then into Southeast Asia, New Guinea and remote Oceania, they were largely replaced by dogs belonging to other lineages in the last 2,000 years in present-day China, especially North China.

Zoo-archaeological and genetic evidence suggest that pigs were domesticated independently in Central China and Eastern Anatolia along with the development of agricultural communities and civilizations. However, the genetic history of domestic pigs, especially in China, has not been fully explored. In this study, we generate 42 complete mitochondrial DNA sequences from ∼7500- to 2750-year-old individuals from the Yellow River basin. Our results show that the maternal genetic continuity of East Asian domestic pigs dates back to at least the Early to Middle Neolithic. In contrast, the Near Eastern ancestry in European domestic pigs saw a near-complete genomic replacement by the European wild boar. The majority of East Asian domestic pigs share close haplotypes, and the most recent common ancestor of most branches dates back to less than 20,000 years before present, inferred using new substitution rates of whole mitogenomes or combined protein-coding regions. Two major population expansion events of East Asian domestic pigs coincided with changes in climate, widespread adoption of introduced crops, and the development of agrarian societies. These findings add to our understanding of the maternal genetic composition and help to complete the picture of domestic pig evolutionary history in East Asia.

Past human genetic diversity and migration between southern China and Southeast Asia have not been well characterized, in part due to poor preservation of ancient DNA in hot and humid regions. We sequenced 31 ancient genomes from southern China (Guangxi and Fujian), including two ∼12,000- to 10,000-year-old individuals representing the oldest humans sequenced from southern China. We discovered a deeply diverged East Asian ancestry in the Guangxi region that persisted until at least 6,000 years ago. We found that ∼9,000- to 6,000-year-old Guangxi populations were a mixture of local ancestry, southern ancestry previously sampled in Fujian, and deep Asian ancestry related to Southeast Asian Hoabinhian hunter-gatherers, showing broad admixture in the region predating the appearance of farming. Historical Guangxi populations dating to ∼1,500 to 500 years ago are closely related to Tai-Kadai and Hmong-Mien speakers. Our results show heavy interactions among three distinct ancestries at the crossroads of East and Southeast Asia.

Given a degenerate $(n+1)$-simplex in a $d$-dimensional space $M^d$ (Euclidean, spherical or hyperbolic space, and $d\geq n$), for each $k$, $1\leq k\leq n$, Radon's theorem induces a partition of the set of $k$-faces into two subsets. We prove that if the vertices of the simplex vary smoothly in $M^d$ for $d=n$, and the volumes of $k$-faces in one subset are constrained only to decrease while in the other subset only to increase, then any sufficiently small motion must preserve the volumes of all $k$-faces; and this property still holds in $M^d$ for $d\geq n+1$ if an invariant $c_{k-1}(\alpha^{k-1})$ of the degenerate simplex has the desired sign. This answers a question posed by the author, and the proof relies on an invariant $c_k(\omega)$ we discovered for any $k$-stress $\omega$ on a cell complex in $M^d$. We introduce a characteristic polynomial of the degenerate simplex by defining $f(x)=\sum_{i=0}^{n+1}(-1)^{i}c_i(\alpha^i)x^{n+1-i}$, and prove that the roots of $f(x)$ are real for the Euclidean case. Some evidence suggests the same conjecture for the hyperbolic case., Comment: 27 pages, 2 figures. To appear in Discrete & Computational Geometry

Polymer composites with high thermal conductivity and good mechanical properties have considerable potential for application in modern micro-electronic devices. In this study, novel core-shell structured fillers (denoted as F-GA) were synthesized by covalently linking aluminum oxide modified with poly (dopamine) and graphene oxide. F-GA/natural rubber (NR) composites were prepared by vacuum-assisted filtration and their thermal conductivity and mechanical properties were investigated. The thermal conductivity of the F-GA/NR composites was 0.863 W/m·K at 25 wt% F-GA filler loading. In addition, the F-GA/NR composites exhibited outstanding mechanical properties and good electrical insulation properties. The interfacial thermal resistance was reduced because of the presence of covalent bonds and three-dimensional structures. The F-GA/NR composites prepared in the present study have a broad application prospects in advanced electronic packaging materials.

Sauropod tracks from the Early Jurassic Maanshan Member of the Ziliujing Formation in the Dazhuanwan area of Guizhou represent the first Jurassic dinosaur track record for this province. The best preserved and longest trackway is narrow gauge (Brontopodus type), and indicates a relatively small trackmaker (footprint length ~35.0 cm). In conjunction with sauropodomorph skeletal remains these tracks suggest that basal sauropodomorphs and primitive sauropods coexisted in this region during the Early Jurassic. This pattern is same in the Lufeng and Sichuan basins. Thus, sauropod tracks from southwest China are diverse in the Early Jurassic, and include narrow gauge Parabrontopodus, wide gauge Brontopodus-type, and basal sauropodomorph tracks.

Dental remains provide crucial evidence for interpreting a populations’ affinity as well as human evolution. Recent studies of fossil human teeth have enriched our current view of morphological variation during the Pleistocene in East Asia. In the present paper, we describe a newly discovered late Pleistocene human tooth, a lower third premolar from the Weijiadong cave in Bijie in south-western China, which is dated around 18-20Ka BP using AMS Carbon 14 dating. The tooth is identified as belonging to an early modern human based on its morphology and size. The Tomes’ root is present in this lower third premolar, one of the non-metrical dental traits developed genetically. Moreover, we examine most of the fossil lower third premolars collected from China, as well as material from several Neolithic and historical human assemblages. We find that the Tomes’ root is very common in Chinese human fossils and occurs in high frequency in Neolithic and historic human remains from China. We suggest the high frequency of Tomes’ root may serve as a non-metric dental trait to support inferences regarding regional continuity of human evolution in East Asia.

Let $M^d$ be the spherical, Euclidean, or hyperbolic space of dimension $d\ge n+1$. Given any degenerate $(n+1)$-simplex $\mathbf{A}$ in $M^d$ with non-degenerate $n$-faces $F_i$, there is a natural partition of the set of $n$-faces into two subsets $X_1$ and $X_2$ such that $\sum_{X_1}V_n(F_i)=\sum_{X_2}V_n(F_i)$, except for a special spherical case where $X_2$ is the empty set and $\sum_{X_1}V_n(F_i)=V_n(\mathbb{S}^n)$ instead. For all cases, if the vertices vary smoothly in $M^d$ with a \emph{single} volume constraint that $\sum_{X_1}V_n(F_i)-\sum_{X_2}V_n(F_i)$ is preserved as a constant (0 or $V_n(\mathbb{S}^n)$), we prove that if a \emph{stress} invariant $c_{n-1}(\alpha^{n-1})$ of the degenerate simplex is non-zero, then the vertices will be confined to a lower dimensional $M^n$ for any sufficiently small motion. This answers a question of the author and we also show that in the Euclidean case, $c_{n-1}(\alpha^{n-1})=0$ is equivalent to the vertices of a \emph{dual} degenerate $(n+1)$-simplex lying on an $(n-1)$-sphere in $\mathbb{R}^n$., Comment: 17 pages. To appear in Beitr\"age zur Algebra und Geometrie / Contributions to Algebra and Geometry

Summary Present-day giant pandas (Ailuropoda melanoleuca) are estimated to have diverged from their closest relatives, all other bears, ∼20 million years ago, based on molecular data [1]. With fewer than 2,500 individuals living today [2], it is unclear how well genetic data from extant and historical giant pandas [3] reflect the past [3]. To date, there has been no complete mitochondrial DNA (mtDNA) sequenced from an ancient giant panda. Here, we use ancient DNA capture techniques [4] to sequence the complete mitochondrial genome of a ∼22,000-year-old giant panda specimen (radiocarbon date of 21,910–21,495 cal BP with ± 2σ at 95.4% probability; Lab.no Beta-473743) from the Cizhutuo Cave, in Leye County, Guangxi Province, China (Figure 1A). Its date and location in Guangxi, where no wild giant pandas live today, as well as the difficulty of DNA preservation in a hot and humid region, place it as a unique specimen to learn about ancient giant pandas from the last glacial maximum. We find that the mtDNA lineage of the Cizhutuo panda coalesced with present-day pandas ∼183 thousand years ago (kya, 95% HPD, 227–144 kya), earlier than the time to the most recent common ancestor (TMRCA) of mtDNA lineages shared by present-day pandas (∼72 kya, 95% HPD, 94–55 kya, Supplemental Information). Furthermore, the Cizhutuo panda possessed 18 non-synonymous mutations across six mitochondrial genes. Our results show that the Cizhutuo mtDNA lineage underwent a distinct history from that of present-day populations.

S-nitrosoglutathione reductase (GSNOR) is the key enzyme controlling the intracellular levels of S-nitrosoglutathione and S-nitrosothiols. GSNOR has been implicated in many biological processes, such as the cardiovascular and respiratory systems. However, the role of GSNOR, the sole brain alcohol dehydrogenase, in the nervous systems is still largely a mystery. Here we report that GSNOR was induced during the PC12 neuronal differentiation. Luciferase assays indicated that the region of -88bp to -73bp of the GSNOR promoter encodes an essential responsive sequence to nerve growth factor (NGF). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays revealed NF-κB binds to this essential sequence, which demonstrates that GSNOR can be activated by NF-κB in response to NGF. Blocking either the neurotrophic tyrosine kinase receptor type 1 (TrkA receptor) for NGF or the downstream MEK1/2 pathway inhibited the increase of GSNOR. In contrast to usual neurogenic signals in response to NGF, GSNOR negatively regulated neurite growth; overexpression of GSNOR significantly decreased the percent of differentiated cells, and knockdown of GSNOR promoted the differentiation. To our knowledge, this is the first time the transcriptional mechanism of GSNOR in neuronal differentiation has been explored. We have defined a novel role of GSNOR in neurite development and provide molecular insights into the control of neurite growth.

A facile additive-free solution method has been developed to fabricate ZnO star-like assemblies, nanosheet-based microspheres and nanorod assemblies by rapid dilution of zinc-bearing alkaline solution with water at 60 °C. The shape of the nanoscale building blocks of the hierarchical structures depends on the supersaturations, which can be adjusted by varying the dilution ratios or the [OH−] to [Zn2+] ratios. The experimental results indicate that with the increase of supersaturation, the building blocks of the hierarchical structures evolve from nanorods to nanosheets and then to nanoparticles. The formation of ZnO nanorod assemblies involves the initial precipitation of the e-Zn(OH)2 intermediate followed by a relatively slow phase transformation process, while ZnO nanosheet-based microspheres and star-like assemblies are constructed within 30 seconds due to the rapid increase of supersaturation induced by dilution, involving the oriented attachment and the random aggregation mechanisms, respectively. Photoluminescence results reveal that the hierarchical structures are rich with singly and doubly ionized oxygen vacancies. The photocatalytic activities of the ZnO hierarchical structures were also evaluated by the degradation of rhodamine B under ultraviolet light. The photocatalytic performance depends on the content of oxygen vacancies as well as the specific surface area.

The gain Surface plasmon resonance (SPR) chip can compensate for the SPR loss, which can improve the sensitivity of the SPR analysis system. In this paper, we design an SPR chip that includes a glass substrate, a gain layer, and a metal layer. Wherein the gain layer is a film obtained by adding IR-140 fuel to different concentrations of methylene chloride in which polymethyl methacrylate (PMMA) is dissolved. Then, we prepared a series of chips with a specific gravity of 0.4%, 0.8%, 1.2%, and 1.6% for the IR-140 in the gain dielectric layer. The fitting effect of the 2nd to 11th order polynomial fitting on the SPR curve is studied, and the SPR curve in this paper is processed by the preferred ninth order polynomial fitting. Finally, by studying the relationship between the thickness of the gain layer and the absorption peak generated by the SPR chip, a chip having an IR-140 dye specific gravity of 0.4% is preferred. The gain layer of the gain SPR chip is also expected to be further studied to further increase its sensitivity.

Enamel stable carbon isotope analyses were conducted on the large fossil ape Gigantopithecus blacki and an associated mammalian megafauna from Longgudong Cave in Jianshi and Juyuandong Cave in Liucheng, South China. The range in delta (13)C values (-18.8aEuro degrees to -14.1aEuro degrees) indicates that G. blacki and other large mammals fed on solely C3 biomass, and lived in forest habitats, and not open country or savannas. These results are consistent with other faunal and floral analyses for that time. The diet and habitat of G. blacki were significantly different from those of early hominins (Australopithecus and Paranthropus) from South and East Africa. Extinction of G. blacki probably was a result of forest habitat fragmentation and deterioration.

Dispersive ZnO nanoparticles with a primary particle size of about 70 nm and an average agglomerate size of about 2.0 μm were synthesized via the precipitation-thermal decomposition route using ZnSO4 and Na2CO3 as the reactants and sodium dodecyl sulfate (SDS) as the surface modification agent. The presence of minor amounts of SDS in the formation of hydrozicite (Zn5(CO3)2(OH)6) precursor changed the agglomeration size of ZnO from 9.7 to 2.0 μm and the primary particle size of ZnO from about 45 to 70 nm. Molecular simulation based on the DISCOVER model and COMPASS force field indicated that SDS was adsorbed on the surface of Zn5(CO3)2(OH)6 mainly via the coulomb and hydrogen bond interactions.

Uniform ZnO whiskers with a length of 3.5–4.0 μm and a diameter of 180 nm have been synthesised via the EDTA–assisted hydrothermal route, using ZnO nanoparticles as the raw material and NaOH solution as the reaction medium. In order to convert the ZnO nanoparticles to ZnO whiskers via the dissolution–hydrothermal precipitation route, ZnO nanoparticles were firstly dissolved in concentrated NaOH solutions at room temperature and then diluted with water to form the super–saturated meta–stable solution before hydrothermal treatment. The presence of minor amount of EDTA favoured the 1D growth of ZnO whiskers. The possible growth mechanism of ZnO whiskers and the effect of EDTA were discussed from the viewpoint of thermodynamic analysis.

Herein we report a facile anion-aided hydrothermal route for the controllable synthesis of CuO assemblies from chrysanthemum-like structures to highly dispersed microspheres in a high morphological yield ( ∼ 100%). The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The formation mechanism was related to the classical anion-additive selective adsorption upon particles growth and the self-assembly process of building units assisted by cetyltrimethylammonium bromide.