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1.
Nature ; 632(8023): 108-113, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38961285

RESUMEN

Genetic and fragmented palaeoanthropological data suggest that Denisovans were once widely distributed across eastern Eurasia1-3. Despite limited archaeological evidence, this indicates that Denisovans were capable of adapting to a highly diverse range of environments. Here we integrate zooarchaeological and proteomic analyses of the late Middle to Late Pleistocene faunal assemblage from Baishiya Karst Cave on the Tibetan Plateau, where a Denisovan mandible and Denisovan sedimentary mitochondrial DNA were found3,4. Using zooarchaeology by mass spectrometry, we identify a new hominin rib specimen that dates to approximately 48-32 thousand years ago (layer 3). Shotgun proteomic analysis taxonomically assigns this specimen to the Denisovan lineage, extending their presence at Baishiya Karst Cave well into the Late Pleistocene. Throughout the stratigraphic sequence, the faunal assemblage is dominated by Caprinae, together with megaherbivores, carnivores, small mammals and birds. The high proportion of anthropogenic modifications on the bone surfaces suggests that Denisovans were the primary agent of faunal accumulation. The chaîne opératoire of carcass processing indicates that animal taxa were exploited for their meat, marrow and hides, while bone was also used as raw material for the production of tools. Our results shed light on the behaviour of Denisovans and their adaptations to the diverse and fluctuating environments of the late Middle and Late Pleistocene of eastern Eurasia.


Asunto(s)
Cuevas , Fósiles , Hominidae , Proteómica , Animales , Hominidae/clasificación , Hominidae/genética , Historia Antigua , Humanos , Mandíbula/anatomía & histología , China , ADN Mitocondrial/genética , Huesos/química , Huesos/anatomía & histología , Arqueología , Filogenia
2.
Front Psychol ; 15: 1276923, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38390408

RESUMEN

Public sentiment can effectively evaluate the public's feelings of well-being in the urban environment and reflect the quality of the spatial environment to a certain extent. Previous studies on the relationship between public sentiment and urban built environmental factors have yielded meaningful results. However, few studies have focused on the effect of micro-built environment on public sentiment at the street level, which directly shapes people's perceptions. In addition, the nonlinear relationship and synergistic effect among urban built environmental factors have been commonly disregarded in previous studies, resulting in an incomplete understanding of the impact of urban built environment on public emotions. Therefore, this paper takes San Francisco as a study case to explore the complex relationship between urban built environmental factors and public emotions. Specifically, this paper measures the polarity of public emotions through sentiment analysis on Twitter data, establishes a comprehensive built environment index system from both macro- and micro- perspectives, and subsequently explores the complex relationship between the urban built environment and public sentiment through the OLS model and Shapley Additive Explanation algorithm. Results show that: (1) micro-built environmental factors have a significant influence on public emotion, although they have been frequently ignored. (2) Public sentiment tends to be more positive in areas with recreation facilities, mixed land use, rich street view visual environment, suitable thermal and acoustic environment, balanced income, and a suitable degree of high population density. (3) A nonlinear relationship and threshold effect exist between the built environmental variables and the semantic orientations of public emotion. Environment improvement strategies based on the synergic effect between variables can effectively promote the generation of positive emotions. Our empirical findings can offer valuable insights to promote feelings of well-being and foster an urban development approach through strategic interventions within the urban built environment.

3.
J Opt Soc Am A Opt Image Sci Vis ; 40(10): 1908-1917, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37855546

RESUMEN

This paper proposes a staircase joint optimization scheme (SJOS) with alternating diagonal interference cancellation and power allocation in an underwater wireless optical communication system based on nonorthogonal multiple access (UWOC-NOMA) with the multi-user paired. The scheme employs the directional iteration to alternatively optimize the subproblems of the interference cancellation and the power allocation. Furthermore, a one-way sorting algorithm based on the alternating diagonal interference cancellation and power allocation subalgorithm based on the conjugate gradient method are presented to solve the two subproblems, respectively. Simulation results show that the algorithm effectively reduces the average outage probability of the system with fast convergence, even with an increase in the number of paired users.

4.
J Math Biol ; 84(4): 30, 2022 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35274161

RESUMEN

The present paper is devoted to the investigation of population dynamics under climate change. The evolution of species is modelled by a reaction-diffusion equation in a spatio-temporally heterogeneous environment described by a climate envelope that shifts with a time-dependent speed function. For a general almost-periodic speed function, we establish the persistence criterion in terms of the sign of the approximate top Lyapunov exponent and, in the case of persistence, prove the existence of a unique forced wave solution that dominates the population profile of species in the long run. In the setting for studying the effects of fluctuations in the shifting speed or location of the climate envelope, we show by means of matched asymptotic expansions and numerical simulations that the approximate top Lyapunov exponent is a decreasing function with respect to the amplitude of fluctuations, yielding that fluctuations in the shifting speed or location have negative impacts on the persistence of species, and moreover, the larger the fluctuation is, the more adverse the effect is on the species. In addition, we assert that large fluctuations can always drive a species to extinction. Our numerical results also show that a persistent species under climate change is invulnerable to mild fluctuations, and becomes vulnerable when fluctuations are so large that the species is endangered. Finally, we show that fluctuations of amplitude less than or equal to the speed difference between the shifting speed and the critical speed are too weak to endanger a persistent species.


Asunto(s)
Cambio Climático , Ecosistema , Modelos Biológicos , Dinámica Poblacional
5.
Front Public Health ; 10: 847399, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35265579

RESUMEN

Large-scale public buildings (e.g., stadiums and comprehensive hospitals) in modern cities provide places for various social activities. However, all of these public places encounter the scenario of large passenger flow and crowd gathering, which is highly likely to induce serious safety problems, such as stampedes. Previous studies have shown that efficient evacuation is an important way to ensure the safety of dense crowds in public places. This study aims to explore the optimization methods to improve the evacuation efficiency of public buildings. Two strategies considering plane partition and multi-floor layout are proposed for plane evacuation and vertical evacuation, respectively. Simulation scenarios and models of large stadiums and high-rise hospitals are established to verify the strategies. The results show that plane partition could effectively shorten the total evacuation time, which is due to the optimization of the initial exit choice of individuals and the avoidance of regional congestion in some evacuation channels or exits. Multi-floor layout optimization is an effective management method to arrange the different features of different floors, which could improve the evacuation efficiency for the whole multi-floor building. This study is helpful for building designers and managers to improve the building space layout design and the daily safety management mode.


Asunto(s)
Aglomeración , Administración de la Seguridad , Simulación por Computador , Ambiente , Humanos , Administración de la Seguridad/métodos
6.
J Math Biol ; 84(3): 18, 2022 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-35146563

RESUMEN

In this paper, we propose a diffusive competition model with habitat degradation and homogeneous Neumann boundary conditions in a bounded domain that is partitioned into the healthy region (undisturbed habitat) and the degraded region (due to anthropogenic habitat disturbance). Species follow the Lotka-Volterra competition in the healthy region while in the degraded region species experience only exponential decay (not necessarily at the same rate). This setup is novel in that it requires no positivity assumption on the environmental heterogeneity, either absolute or on average, which would be far too restrictive for the study of the effects of habitat degradation. We rigorously show competitive exclusion and coexistence via global stability analysis. A remarkable finding is that the quality heterogeneity of landscapes can lead to the competitive exclusion of the slower species by the faster species. This result is robust as long as the degraded region has positive area, and moreover is at odds with classical results predicting the deterministic extinction of the stronger species. On the other hand, if the degraded region has intermediate negative effect on the faster competitor, species can coexist. Differing from comparable existing results, coexistence does not rely on a limit as the diffusion coefficients tend to zero or infinity. Together, these results imply that coexistence is always a possibility under this basic, yet general, configuration, providing insights into the varying impacts found through empirical study of habitat loss and fragmentation on species.


Asunto(s)
Ecosistema , Modelos Biológicos , Difusión , Dinámica Poblacional
7.
Orthop Surg ; 11(1): 117-125, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30560591

RESUMEN

OBJECTIVE: To investigate the association between curcumin and the differentially expressed genes (DEG) in synovial tissues of osteoarthritis. METHODS: Microarray analysis was used to screen for the DEG in osteoarthritis synovial cells. Curcumin-related genes were identified through the drug-gene interaction network STITCH (http://stitch.embl.de/cgi/input.pl). Expression levels of fibronectin 1 (FN1) and collagen III protein were measured by western blot. MTT assay was used to examine the effects of different concentrations of curcumin on cell viability. Western blot and quantitative real-time polymerase chain reaction were used to validate the different expression levels of matrix metalloproteinase-3 (MMP3). Clone formation assay, flow cytometry, and the TUNEL method were conducted for detecting the cell proliferation and apoptosis rate. RESULTS: In the two chips of GSE1919 and GSE55235, the average expression of MMP3 in the osteoarthritis group was 63.7% and 12.9% higher than that of the healthy control, respectively. The results of western blot also showed that the average expression of MMP3 in 30 osteoarthritis patients was 132% higher than that of the healthy group, which confirmed that MMP3 was highly expressed in osteoarthritis group. The results of MTT showed that at 72 h, the cell viability of 40 µmol/L curcumin was the lowest and 79.6% lower than for the 0 µmol/L group, so the final curcumin concentration of 40 µmol/L was selected for subsequent experiments. Western blot results further showed that the expression of MMP3 was 44% lower in the untreated groups compared with the curcumin group, and the expressions of FN1 and collagen III were increased by 112% and 84%, respectively, which indicated that curcumin inhibited MMP3 expression and decreased osteoarthritis synovial cell activity. Cloning formation experiments showed that cell numbers increased by 75% and 20.5% in untreated and curcumin groups, and compared with the untreated group, the cells in the curcumin group decreased by 30.8%. Flow cytometry showed that the apoptotic rate in the curcumin group increased by 85.1% compared with the untreated group, but for a single group, MMP3 decreased the apoptotic rate by 53.9% and 46.7%, respectively. CONCLUSIONS: MMP3 was highly expressed in osteoarthritis synovial cells. Curcumin could reduce cell viability, inhibit cell proliferation, increase cell apoptosis, and eventually alleviate inflammation of osteoarthritis by inhibiting the expression of MMP3.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Curcumina/farmacología , Metaloproteinasa 3 de la Matriz/biosíntesis , Osteoartritis de la Rodilla/patología , Membrana Sinovial/efectos de los fármacos , Apoptosis/efectos de los fármacos , Estudios de Casos y Controles , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Metaloproteinasa 3 de la Matriz/genética , Osteoartritis de la Rodilla/enzimología , Membrana Sinovial/enzimología , Membrana Sinovial/patología
8.
J Math Biol ; 77(6-7): 1649-1687, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29332297

RESUMEN

To understand the effects that the climate change has on the evolution of species as well as the genetic consequences, we analyze an integrodifference equation (IDE) models for a reproducing and dispersing population in a spatio-temporal heterogeneous environment described by a shifting climate envelope. Our analysis on the IDE focuses on the persistence criterion, travelling wave solutions, and the inside dynamics. First, the persistence criterion, characterizing the global dynamics of the IDE, is established in terms of the basic reproduction number. In the case of persistence, a unique travelling wave is found to govern the global dynamics. The effects of the size and the shifting speed of the climate envelope on the basic reproduction number, and hence, on the persistence criterion, are also investigated. In particular, the critical domain size and the critical shifting speed are found in certain cases. Numerical simulations are performed to complement the theoretical results. In the case of persistence, we separate the travelling wave and general solutions into spatially distinct neutral fractions to study the inside dynamics. It is shown that each neutral genetic fraction rearranges itself spatially so as to asymptotically achieve the profile of the travelling wave. To measure the genetic diversity of the population density we calculate the Shannon diversity index and related indices, and use these to illustrate how diversity changes with underlying parameters.


Asunto(s)
Cambio Climático , Modelos Biológicos , Animales , Número Básico de Reproducción , Evolución Biológica , Simulación por Computador , Ecosistema , Variación Genética , Genética de Población/estadística & datos numéricos , Conceptos Matemáticos , Densidad de Población , Dinámica Poblacional/estadística & datos numéricos , Análisis Espacio-Temporal
10.
Artículo en Inglés | MEDLINE | ID: mdl-27709111

RESUMEN

The study of single cells has evolved over the past several years to include expression and genomic analysis of an increasing number of single cells. Several studies have demonstrated wide spread variation and heterogeneity within cell populations of similar phenotype. While the characterization of these populations will likely set the foundation for our understanding of genomic- and expression-based diversity, it will not be able to link the functional differences of a single cell to its underlying genomic structure and activity. Currently, it is difficult to perturb single cells in a controlled environment, monitor and measure the response due to perturbation, and link these response measurements to downstream genomic and transcriptomic analysis. In order to address this challenge, we developed a platform to integrate and miniaturize many of the experimental steps required to study single-cell function. The heart of this platform is an elastomer-based integrated fluidic circuit that uses fluidic logic to select and sequester specific single cells based on a phenotypic trait for downstream experimentation. Experiments with sequestered cells that have been performed include on-chip culture, exposure to various stimulants, and post-exposure image-based response analysis, followed by preparation of the mRNA transcriptome for massively parallel sequencing analysis. The flexible system embodies experimental design and execution that enable routine functional studies of single cells.

11.
Appl Opt ; 52(7): 1517-22, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23458807

RESUMEN

A high-stability and high-efficiency ring Ti:sapphire regenerative amplifier is demonstrated based on a double-gating pulse picker at a repetition rate of 1 kHz. Pulse energy up to 5.7 mJ is obtained using a pump energy of 20.0 mJ at 527 nm, corresponding to a relatively high slope efficiency of 30.3%. After a grating compressor, the laser pulse is compressed to 37.2 fs with an energy of 4.1 mJ. The beam quality factors M(2) are 1.4 and 1.3 in tangential and sagittal directions, respectively. The measured root mean square energy stability is better than 0.31% over an 11 h period.

12.
Biotechnol Lett ; 35(1): 115-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22955680

RESUMEN

Seventeen independent transgenic rice plants with the maize anthocyanin regulatory gene Lc under control of the CaMV 35S promoter were obtained and verified by molecular identification. Ten plants showed red spikelets during early development of florets, and the degenerate florets were still red after heading. Additionally, these plants exhibited intense pigmentation on the surface of the anther and the bottom of the ovary. They were unable to properly bloom and were completely sterile. Following pollination with normal pollen, these plants yielded red caryopses but did not mature normally. QRT-PCR analysis indicated that mRNA accumulation of the CHS-like gene encoding a chalcone synthase-related protein was increased significantly in the sterile plant. This is the first report to suggest that upregulation of the CHS gene expression may result in rice sterility and affect the normal development of rice seeds.


Asunto(s)
Antocianinas/genética , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Infertilidad Vegetal/genética , Plantas Modificadas Genéticamente/genética , Zea mays/genética , Aciltransferasas/análisis , Aciltransferasas/genética , Aciltransferasas/metabolismo , Flores/química , Flores/genética , Flores/metabolismo , Hibridación Genética , Oryza/metabolismo , Fenotipo , Proteínas de Plantas/análisis , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa
13.
Opt Lett ; 36(16): 3194-6, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21847205

RESUMEN

Based on a combined scheme of doubled chirped-pulse amplification and a femtosecond noncollinear optical-parametric amplifier, a high-contrast femtosecond laser pulse with energy of up to 32.3 J has been generated by improving the gain efficiency and boosting the pump energy to 120 J in the final amplifier. Our measurements show that the contrast ratio of the main laser pulse is around 10(10) within the time scale of -400 ps and the duration of compressed pulse is 27.9 fs, corresponding to a peak power of 1.16 PW.

14.
Opt Express ; 19(25): 25812-22, 2011 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-22273974

RESUMEN

We observed that increasing the clusters size and laser pulse contrast can enhance the X-ray flux emitted by femtosecond-laser-driven-cluster plasma. By focusing a high contrast laser (10(-10)) on large argon clusters, high flux Kα-like X-rays (around 2.96 keV) is generated with a total flux of 2.5 × 10(11) photons/J in 4π and a conversion efficiency of 1.2 × 10-4. In the case of large Kr clusters, the best total flux for L-shell X-rays is 5.3 × 1011 photons/J with a conversion efficiency of 1.3 × 10-4 and, for the Kα X-ray (12.7 keV), it is 8 × 10(8) photons/J with a conversion efficiency of 1.6 × 10-6. Using this X-ray source, a single-shot high-performance X-ray imaging is demonstrated.


Asunto(s)
Argón/química , Argón/efectos de la radiación , Criptón/química , Criptón/efectos de la radiación , Rayos Láser , Luz , Dispersión de Radiación
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