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This paper performs a numerical study regarding the effects of different kinds of coolants on flow and heat transfer in a pin-finned internal channel. A new pin-fin structure detached from one endwall with a round-tip is proposed which aims to increase the heat transfer enhancement. As a contrast, the investigation of the typical fully-attached pin-fin and the flat-tip detached pin-fin is also considered. In order to evaluate the reliability of the numerical method, an experiment of an internal channel with round-tip pin-fin arrays is conducted to serve as the reference, and all cases are carried out with the shear stress transport (SST) turbulence model. The effects of coolants including air, mist/air, steam, and mist/steam are analyzed with the Reynolds number ranging from 15, 000 to 50, 000. The results reveal that the round-tip pin-fin outperforms in heat transfer enhancement and pressure loss deterioration among all three pin-fin structures. With respect to Reynolds numbers, the averaged Nusselt numbers increase gradually for all coolants, and cases of mist/steam achieve the highest values, followed by cases of steam, mist/air, and air, respectively, but the differences between the mist coolants and pure coolants are not obvious as the Reynolds number is lower than 30, 000. In conclusion, cases of mist/steam obtain the best thermal performances, and the internal channel with round-tip pin-fin arrays using mist/steam as coolant is most favorable. (Less)

Travel frequency of people varies widely with occupation, age, gender, ethnicity, income, climate and other factors. Meanwhile, the distribution of the numbers of times people in different regions or with different travel behaviors bitten by mosquitoes may be nonuniform. To reflect these two heterogeneities, we develop a multipatch model to study the impact of travel frequency and human biting rate on the spatial spread of mosquito-borne diseases. The human population in each patch is divided into four classes: susceptible unfrequent, infectious unfrequent, susceptible frequent, and infectious frequent. The basic reproduction number \begin{document}$ \mathcal{R}_0 $\end{document} is defined. It is shown that the disease-free equilibrium is globally asymptotically stable if \begin{document}$ \mathcal{R}_0\leq 1 $\end{document} , and there is a unique endemic equilibrium that is globally asymptotically stable if \begin{document}$ \mathcal{R}_0>1 $\end{document} . A more detailed study is conducted on the single patch model. We use analytical and numerical methods to demonstrate that the model without considering the difference of humans in travel frequency mostly underestimates the risk of infection. Numerical simulations suggest that the greater the difference in travel frequency, the larger the underestimate of the transmission potential. In addition, the basic reproduction number \begin{document}$ \mathcal{R}_0 $\end{document} may decreasingly, or increasingly, or nonmonotonically vary when more people travel frequently.

Based on a comparison of synchronized temperature and salinity data collected in the eastern Qiongzhou Strait and at coastal marine stations, this study finds that, in summer, the variation in salinity near the Weizhou Island in Guangxi is similar to that in the eastern and central portions of the Qiongzhou Strait. Additionally, the Beihai Station in Guangxi exhibits a small salinity variation, whereas the Longmen and Bailongwei Stations, both of which are located far from the Qiongzhou Strait, mainly exhibit continental hydrological characteristics in summer. Moreover, a comparison of the multi-year ocean current data from the Qiongzhou Strait and ocean current observations from the Weizhou Island Station and recently installed current-measuring stations shows that the residual current in the Qiongzhou Strait flows westward in winter and summer. The numerical simulation results also indicate that water from the eastern Qiongzhou Strait enters the Beibu Gulf. The characteristics of the temperature and salinity distributions and analyses of the residual currents further confirm that the western Guangdong coastal current is the main source of the westward transport of water in the Qiongzhou Strait. The primary driver of the formation of the western Guangdong coastal current is the westward flow of freshwater from the Zhujiang (Pearl) River. This water enters the Beibu Gulf via the Qiongzhou Strait and enhances the formation of the cyclonic circulation in the northern Beibu Gulf. In summer, the strong influence of the southwesterly wind leads to the formation of a strong northward coastal current along the western coast of the Beibu Gulf. This process promotes the transport of low-salinity diluted water toward the open ocean and the formation of larger-scale cyclonic circulation around Weizhou Island in the eastern Beibu Gulf. The results of this study regarding the effects of the water inflow from the eastern Qiongzhou Strait to the Beibu Gulf on the Guangxi coastal circulation directly challenge conventional conclusions concerning the transport direction of water through the Qiongzhou Strait in winter and summer.

Vibriosis has caused great economic losses to marine aquaculture with high mortality worldwide. Guangxi province is an important cultured center for tropical marine fi sh species in South China. However, no research focused on epidemiological characterization of vibriosis in golden pompano aquaculture in Guangxi province have been carried out.

As of May 27, 2018, 6 suspected, 13 probable and 35 confirmed cases of Ebola virus disease (EVD) had been reported in Équateur Province, Democratic Republic of Congo. We used reported case counts and time series from prior outbreaks to estimate the total outbreak size and duration with and without vaccine use. We modeled Ebola virus transmission using a stochastic branching process model that included reproduction numbers from past Ebola outbreaks and a particle filtering method to generate a probabilistic projection of the outbreak size and duration conditioned on its reported trajectory to date; modeled using high (62%), low (44%), and zero (0%) estimates of vaccination coverage (after deployment). Additionally, we used the time series for 18 prior Ebola outbreaks from 1976 to 2016 to parameterize the Thiel-Sen regression model predicting the outbreak size from the number of observed cases from April 4 to May 27. We used these techniques on probable and confirmed case counts with and without inclusion of suspected cases. Probabilistic projections were scored against the actual outbreak size of 54 EVD cases, using a log-likelihood score. With the stochastic model, using high, low, and zero estimates of vaccination coverage, the median outbreak sizes for probable and confirmed cases were 82 cases (95% prediction interval [PI]: 55, 156), 104 cases (95% PI: 58, 271), and 213 cases (95% PI: 64, 1450), respectively. With the Thiel-Sen regression model, the median outbreak size was estimated to be 65.0 probable and confirmed cases (95% PI: 48.8, 119.7). Among our three mathematical models, the stochastic model with suspected cases and high vaccine coverage predicted total outbreak sizes closest to the true outcome. Relatively simple mathematical models updated in real time may inform outbreak response teams with projections of total outbreak size and duration.

BackgroundAs of May 27, 2018, 54 cases of Ebola virus disease (EVD) were reported in Équateur Province, Democratic Republic of Congo. We used reported case counts and time series from prior outbreaks to estimate the current outbreak size and duration with and without vaccine use.MethodsWe modeled Ebola virus transmission using a stochastic branching process model with a negative binomial distribution, using both estimates of reproduction number R declining from supercritical to subcritical derived from past Ebola outbreaks, as well as a particle filtering method to generate a probabilistic projection of the future course of the outbreak conditioned on its reported trajectory to date; modeled using 0%, 44%, and 62% estimates of vaccination coverage. Additionally, we used the time series for 18 prior Ebola outbreaks from 1976 to 2016 to parameterize a regression model predicting the outbreak size from the number of observed cases from April 4 to May 27.ResultsWith the stochastic transmission model, we projected a median outbreak size of 78 EVD cases (95% credible interval: 52, 125.4), 86 cases (95% credible interval: 53, 174.3), and 91 cases (95% credible interval: 52, 843.5), using 62%, 44%, and 0% estimates of vaccination coverage. With the regression model, we estimated a median size of 85.0 cases (95% prediction interval: 53.5, 216.6).ConclusionsThis outbreak has the potential to be the largest outbreak in DRC since 2007. Vaccines are projected to limit outbreak size and duration but are only part of prevention, control, and care strategies.

Localization problem is an important and challenging topic in today's wireless sensor networks. In this paper, a novel localization refinement algorithm for LAEP, which is a range-free localization algorithm by using expected hop progress, has been put forward. The proposed localization refinement algorithm, called as CVLR, is based on position correction vectors and can resolve the LAEP's hop-distance ambiguity problem, which can lead to adjacent unknown nodes localized at the same or very close positions. CVLR can make full use of the relative position relationship of 1-hop neighboring nodes (called as CVLR1), or 1-hop and 2-hop neighboring nodes (called as CVLR2), to iteratively refine their localization positions. Furthermore, from localization accuracy and energy dissipation perspective, we optimize the communication process of CVLR2 and propose an energy-efficient improved CVLR. Simulation results show that the localization accuracy of CVLR1, CVLR2, and the improved CVLR are obviously higher than that of LAEP and DV-RND.

Mammalian shelterin proteins POT1 and TPP1 form a stable heterodimer that protects chromosome ends and regulates telomerase-mediated telomere extension. However, how POT1 interacts with TPP1 remains unknown. Here we present the crystal structure of the C-terminal portion of human POT1 (POT1C) complexed with the POT1-binding motif of TPP1. The structure shows that POT1C contains two domains, a third OB fold and a Holliday junction resolvase-like domain. Both domains are essential for binding to TPP1. Notably, unlike the heart-shaped structure of ciliated protozoan Oxytricha nova TEBPα–β complex, POT1–TPP1 adopts an elongated V-shaped conformation. In addition, we identify several missense mutations in human cancers that disrupt the POT1C–TPP1 interaction, resulting in POT1 instability. POT1C mutants that bind TPP1 localize to telomeres but fail to repress a DNA damage response and inappropriate repair by A-NHEJ. Our results reveal that POT1 C terminus is essential to prevent initiation of genome instability permissive for tumorigenesis., Human telomeres are protected by a specialized shelterin complex composed of six proteins. Here the authors structurally characterize the interaction between the POT1-TPP1 shelterin component and identify mutations associated with genome instability and cancer that disrupt the POT1-TPP1 interaction.

In space, circadian rhythms are prone to alteration. Head-down (–6°) bed rest (HDBR) is an approach simulating the weightlessness condition, which allows effects of weightlessness on physiological variables to be studied on the ground. In this work, we analyzed the changes in diurnal rhythms of activity, sleep-wake cycles, and cardiovascular responses in a 45-day HDBR. All subjects exhibited increased daytime sleep, whereas the total sleep time was comparable. The results of wrist activity monitoring showed a significant reduction during HDBR and recovery after HDBR. Moreover, changes in the average frequency, amplitude, and phase of heart rate were observed. Analysis of heart rate variability showed a decrease in both high-frequency and low-frequency power after HDBR. Together, these data demonstrate that HDBR can alter the diurnal rhythms of a number of physiological processes, some of which might be attributed to reduction in activity of the autonomic nervous system.

Dong, D.; Zhu, D.; Ya, H.; Chen, X., and Chen, B., 2019. Typhoon-driven storm jet generation and water level fluctuations near the coast of Guangxi. In: Guido-Aldana, P.A. and Mulahasan, S...

Chen, B.; Dong, D.; Qin, X.; Xu, M.; Chen, X., and Shi, M., 2019. Relationship between the occurrence of red tides and the dynamic response mechanisms in the northern Beibu Gulf. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 185–193. Coconut Creek (Florida), ISSN 0749-0208.Unlike the common outbreak mechanism of red tides, the northern Beibu Gulf in the Guangxi Zhuang Autonomous Region of China experiences frequent red tides with distinct characteristics, such as large distances from the mainland and the presence of industrial pollution. By tracing the sources and transport of the high concentrations of nitrogen and phosphorus, the relationship between pollutant transport and the dynamic response mechanisms was explored. The results showed that the concentrations of nitrogen and phosphorus nutrients in the areas of red tide outbreaks near Weizhou Island and in the Qinzhou Gulf in the northern Beibu Gulf were higher than those in the surrounding areas. However, the high concentrations of nitrogen and phosphorus nutrients in the northern Beibu Gulf did not originate from terrestrial pollution from Guangxi Province; rather, these pollutants originated on the east coast of China and were transported through the Qiongzhou Strait. The primary sources were the Pearl River Estuary and the coastal waters of eastern Guangdong. In addition, the differences in the concentration distributions of nitrogen and phosphorus nutrients between the east and west coasts of the Qinzhou Gulf in the northern Beibu Gulf were clearly related to dynamic response mechanisms.

Circadian clocks are internal molecular time-keeping mechanisms that enable organisms to adjust their physiology and behavior to the daily surroundings. Misalignment of circadian clocks leads to both physiological and health impairment. Post-transcriptional regulation and translational regulation of circadian clocks have been extensively investigated. In addition, accumulating evidence has shed new light on the involvement of ribonucleoprotein complexes (RNPs) in the post-transcriptional regulation of circadian clocks. Numerous RNA-binding proteins (RBPs) and RNPs have been implicated in the post-transcriptional modification of circadian clock proteins in different model organisms. Herein, we summarize the advances in the current knowledge on the role of RNP complexes in circadian clock regulation.

The increasing and decreasing water level in Guangxi near the coast is mainly caused by typhoon-induced storm surges. The maximum values of increase and decrease recorded at the Beihai Station over the last 42 years are 1.45 m and -1.87 m. The water level first decreases and then increases in Guangxi near the coast. Apart from the direct influence of typhoons, the westward coastal-trapped wave along the Guangdong continental shelf is also greatly affected. A portion of the westward coastal-trapped wave passed directly through the Qiongzhou Strait into Beibu Gulf, and the other portion passed through the southern part of Hainan Island into the Beibu Gulf. On July 2, 2001, the westward coastal-trapped wave caused by Typhoon Durian induced a strong westward flow along the Guangxi coast, and the geostrophic flow velocity on the surface reached 92cm/s. On July 6, 2001, though Typhoon Utor landed at the northern part of the Pearl River Estuary, it widely induced a 20-cm increase in the water level in Guangxi near the coast on July 8. Apart from the direct and indirect influences of typhoons on the fluctuation of the water level along the Guangxi coast, the particular topography and atmospheric gravity wave also have affect the fluctuation of the water level.

In spaceflight human circadian rhythms and sleep patterns are likely subject to change, which consequently disturbs human physiology, cognitive abilities and performance efficiency. However, the influence of microgravity on sleep and circadian clock as well as the underlying mechanisms remain largely unknown. Placing volunteers in a prone position, whereby their heads rest at an angle of -6° below horizontal, mimics the microgravity environment in orbital flight. Such positioning is termed head-down bed rest (HDBR). In this work, we analysed the influence of a 45-day HDBR on physiological diurnal rhythms. We examined urinary electrolyte and hormone excretion, and the results show a dramatic elevation of cortisol levels during HDBR and recovery. Increased diuresis, melatonin and testosterone were observed at certain periods during HDBR. In addition, we investigated the changes in urination and defecation frequencies and found that the rhythmicity of urinary frequency during lights-off during and after HDBR was higher than control. The grouped defecation frequency data exhibits rhythmicity before and during HDBR but not after HDBR. Together, these data demonstrate that HDBR can alter a number of physiological processes associated with diurnal rhythms.