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The limited amount of available orthogonal channels and noise interference are two major issues to constrain performances of multi-channel MAC protocols in wireless sensor networks (WSN).In conjunction with features of data gathering networks,a partitioning-based multi-channel MAC protocol was designed.Initially it partitioned network into several sub-trees with lower collision factor,without increasing the total value of interference around the whole network.Furthermore,it adopted a coarse-grained channel assignment strategy on basis of graph coloring theory,in order to ensure each sub-tree work on a relative optimal channel.Simulation results show that the proposed MAC protocol can significantly improve throughput and reduce end-to-end latency and packet loss.

The seasonal evolution of snow and ice on Lake Orajärvi, northern Finland, was investigated for three consecutive winter seasons. Material consisting of numerical weather prediction model (HIRLAM) output, weather station observations, manual snow and ice observations, high spatial resolution snow and ice temperatures from ice mass balance buoys (SIMB), and Moderate Resolution Imaging Spectroradiometer (MODIS) lake ice surface temperature observations was gathered. A snow/ice model (HIGHTSI) was applied to simulate the evolution of the snow and ice surface energy balance, temperature profiles and thickness. The weather conditions in early winter were found critical in determining the seasonal evolution of the thickness of lake ice and snow. During the winter season (Nov.–Apr.), precipitation, longwave radiative flux and air temperature showed large inter-annual variations. The uncertainty in snow/ice model simulations originating from precipitation was investigated. The contribution of snow to ice transformation was vital for the total lake ice thickness. At the seasonal time scale, the ice bottom growth was 50–70% of the total ice growth. The SIMB is suitable for monitoring snow and ice temperatures and thicknesses. The Mean Bias Error (MBE) between the SIMB and borehole measurements was −0.7 cm for snow thicknesses and 1.7 cm for ice thickness. The temporal evolution of MODIS surface temperature (three seasons) agrees well with SIMB and HIGHTSI results (correlation coefficient, R=0.81). The HIGHTSI surface temperatures were, however, higher (2.8°C≤MBE≤3.9°C) than the MODIS observations. The development of HIRLAM by increasing its horizontal and vertical resolution and including a lake parameterisation scheme improved the atmospheric forcing for HIGHTSI, especially the relative humidity and solar radiation. Challenges remain in accurate simulation of snowfall events and total precipitation.

Snow and ice thermodynamics of Bear Lake (Alaska) are investigated with a simple freshwater lake model (FLake) and a more complex snow and ice thermodynamic model (HIGHTSI). A number of sensitivity experiments have been carried out to investigate the influence of snow and ice parameters and of different complexity on the results. Simulation results are compared with observations from the Alaska Lake Ice and Snow Observatory Network. Adaptations of snow thermal and optical properties in FLake can largely improve accuracy of the results. Snow-to-ice transformation is important for HIGHTSI to calculate the total ice mass balance. The seasonal maximum ice depth is simulated in FLake with a bias of −0.04 m and in HIGHTSI with no bias. Correlation coefficients between ice depth measurements and simulations are high (0.74 for FLake and 0.9 for HIGHTSI). The snow depth simulation can be improved by taking into account a variable snow density. Correlation coefficients for surface temperature are 0.72 for FLake and 0.81 for HIGHTSI. Overall, HIGHTSI gives slightly more accurate surface temperature than FLake probably due to the consideration of multiple snow and ice layers and the expensive iteration calculation procedure.

Reflection and transmission of irradiance by the combined snow and sea ice layer were measured at an ice camp (ca. 10 days) and several short-term stations (ca. 2 h) established in the western sector of the Arctic Ocean above 80°N during the 2010 summer. These measurements were made with an intention to quantify the apparent optical properties of snow and sea ice, and to evaluate their roles in the mass balance of snow-covered sea ice in the High Arctic. The integrated 350–920 nm albedo ranged from 0.54 to 0.88, and was primarily dependent on the geophysical properties of snow, but not those of sea ice. This implies that all snow cover was still optically thick, even though snow melting had commenced at all measurement sites. For sea ice about 1.66 m thick and covered by 2.5–8.5 cm of snow at the ice camp, the integrated 350–920 nm transmittance ranged from 0.017 to 0.065. Rapid snow melting resulting from an event of slight drizzle doubled the available solar irradiance under the ice (from ca. 3.6 to 7.2 W·m−2), which further accelerated ice-bottom decay. During the measurement at the camp, the temporally averaged incident solar irradiance at 320–950 nm was 110.6±33.6 W·m−2, 29.2±2.9% of which was absorbed by snow and sea ice and utilized to melt snow and sea ice. The melting of snow and sea ice had a distinctly greater effect on the spectral reflection and transmission for the near-infrared spectrum than for the ultraviolet and visible spectra.

Snow and ice thermodynamics was simulated applying a one-dimensional model for an individual ice season 2008–2009 and for the climatological normal period 1971–2000. Meteorological data were used as the model input. The novel model features were advanced treatment of superimposed ice and turbulent heat fluxes, coupling of snow and ice layers and snow modelled from precipitation. The simulated snow, snow–ice and ice thickness showed good agreement with observations for 2008–2009. Modelled ice climatology was also reasonable, with 0.5 cm d−1 growth in December–March and 2 cm d−1 melting in April. Tuned heat flux from water to ice was 0.5 W m−2. The diurnal weather cycle gave significant impact on ice thickness in spring. Ice climatology was highly sensitive to snow conditions. Surface temperature showed strong dependency on thickness of thin ice (

This paper focuses on thermal environmental conditions in the stone dwellings of a Tibetan village in Danba County, Sichuan, China, in winter. During the study, field measurements and subjective survey studies were collected, simultaneously, to provide a comprehensive understanding of the thermal comfort conditions that were experienced by residents in cold rural areas of Sichuan. Subjective surveys involved questions about thermal comfort perceptions and acceptability in cold conditions. The status of thermal comfort and characteristics of indoor environmental qualities were investigated in the study. The majority of survey participants (47% and 74%) voted as “slightly cool” for temperature, and “slightly dry” for humidity in the studied typical winter days, respectively. The available adaptive opportunities for the residents were investigated through the survey studies. Adjusting clothing, drinking hot beverages, blocking air infiltration through windows, and changing activities were the most common adaptive measures. An adaptive coefficient ( λ ) was determined based on adaptive predicted mean votes (aPMV) models using least square methods to assess the different adaptation measures in the region. Findings of this study provided a valuable reference for thermal comfort adaptations in cold climates, where limited adaptive opportunities were available due to the low standard of living.

Background and objective The relationship between the virus and carcinomas has attracted attention and China may be highly infected-District with HPV. It was unclear that whether there has been HPV infection in squamous cell carcinomas and the occurrence and development of lung cancer has the relation with HPV. This experiment applied situ hybridization and immunohistochemical techniques. This study is to investigate the relationship between the status of HPV16/18 infection between the expression of Bcl-2 and Bax in squamous cell carcinomas of the lung. Methods In 44 patients with squamous cell carcinomas of the lung, HPV 16/18 DNA was examined by in situ hybridization, expression of Bcl-2 and Bax was revealed by immunohistochemistry and koilocytes was detected in carcinomas tissues by morphologic examination. Results Of 44 patients with squamous cell carcinomas of the lung, 12 (27.27%) were found to be HPV negative. Twenty-three (52.27%) were found to be integrated form HPV, 9 (20.45%) were found to be large number of episomal form and a few integrated form HPV. And no simplex episomal form HPV was found. HPV 16/18 DNA could not be detected in 15 non-carcinomas tissues. A significantly higher 16/18 DNA positive rates in carcinomas tissues compared to non-carcinomas tissues (P

In wireless sensor and actor networks, when an event is detected, the sensor node needs to transmit an event report to inform the actor. Since the actor moves in the network to execute missions, its location is always unavailable to the sensor nodes. A popular solution is the search strategy that can forward the data to a node without its location information. However, most existing works have not considered the mobility of the node, and thus generate significant energy consumption or transmission delay. In this paper, we propose the trail-based search (TS) strategy that takes advantage of actor’s mobility to improve the search efficiency. The main idea of TS is that, when the actor moves in the network, it can leave its trail composed of continuous footprints. The search packet with the event report is transmitted in the network to search the actor or its footprints. Once an effective footprint is discovered, the packet will be forwarded along the trail until it is received by the actor. Moreover, we derive the condition to guarantee the trail connectivity, and propose the redundancy reduction scheme based on TS (TS-R) to reduce nontrivial transmission redundancy that is generated by the trail. The theoretical and numerical analysis is provided to prove the efficiency of TS. Compared with the well-known expanding ring search (ERS), TS significantly reduces the energy consumption and search delay.

We estimate two essential sea ice parameters—namely, sea ice concentration (SIC) and sea ice thickness (SIT)—for the Bohai Sea using a combination of a thermodynamic sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiometer. We compare the SIC and SIT estimation results with in-situ measurements conducted in the study area and estimates based on independent EO data from near-infrared/optical instruments. These comparisons suggest that the SAR-based discrimination between sea ice and open-water works well, and areas of thinner and thicker ice can be distinguished. A larger comprehensive training dataset is needed to set up an operational algorithm for the estimation of SIC and SIT.

The problem of data recovery in multiway arrays (i.e., tensors) arises in many fields such as computer vision, image processing, and traffic data analysis. In this paper, we propose a scalable and fast algorithm for recovering a low-n-rank tensor with an unknown fraction of its entries being arbitrarily corrupted. In the new algorithm, the tensor recovery problem is formulated as a mixture convex multilinear Robust Principal Component Analysis (RPCA) optimization problem by minimizing a sum of the nuclear norm and the ℓ1-norm. The problem is well structured in both the objective function and constraints. We apply augmented Lagrange multiplier method which can make use of the good structure for efficiently solving this problem. In the experiments, the algorithm is compared with the state-of-art algorithm both on synthetic data and real data including traffic data, image data, and video data.

BACKGROUND: Clotrimazole is an antifungal imidazole derivative showing anti- neoplastic effect in some tumors, but its anticancer potential is still unclear in oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate the antitumor effect of clotrimazole, and to investigate the possible mechanism of clotrimazole-mediated antitumor activity in OSCC. METHODOLOGY: In vitro experiments, the cell viability and clonogenic ability of three human OSCC cell lines CAL27, SCC25 and UM1 were detected after clotrimazole treatment by CCK8 assay and colony formation assay. Cell cycle progression and apoptosis were assessed by flow cytometry, and the involvement of several mediators of apoptosis was examined by western blot analysis. Then, the in vivo antitumor effect of clotrimazole was investigated in CAL27 xenograft model. Immunohistochemistry and western blot analysis were performed to determine the presence of apoptotic cells and the expression of Bcl-2 and Bax in tumors from mice treated with or without clotrimazole. RESULTS: Clotrimazole inhibited proliferation in all three OSCC cell lines in a dose-and time-dependent manner, and significantly reduced the colony formation of OSCC cells in vitro. Clotrimazole caused cell cycle arrest at the G0/G1 phase. In addition, clotrimazole induced apoptosis in OSCC cells, and significantly down-regulated the anti-apoptotic protein Bcl-2 and up-regulated the pro-apoptotic protein Bax. Notably, clotrimazole treatment inhibited OSCC tumor growth and cell proliferation in CAL27 xenograft model. Clotrimazole also markedly reduced Bcl-2 expression and increased the protein level of Bax in tumor tissues of xenograft model. CONCLUSION: Our findings demonstrated a potent anticancer effect of clotrimazole by inducing cell cycle arrest and cellular apoptosis in OSCC.

OBJECTIVE: To investigate the effects of social isolation on oral mucosal healing in rats, and to determine if wound-associated genes and microRNAs (miRNAs) may contribute to this response. METHODS: Rats were group housed or socially isolated for 4 weeks before a 3.5 mm wound was placed on the hard oral palate. Wound closure was assessed daily and tissues were collected for determination of gene expression levels and miRNAs (i.e., miR-29a,b,c and miR-203). The predicted target of these microRNAs (i.e., vascular endothelial growth factor A, VEGFA) was functionally validated. RESULTS: Social isolation stress delayed the healing process of oral palatal mucosal wounds in rats. Lower mRNA levels of interleukin-1β (IL1β), macrophage inflammatory protein-1α (MIP1α), fibroblast growth factor 7 (FGF7), and VEGFA were found in the biopsied tissues of isolated animals on days 1 and/or 3 post-wounding. Intriguingly, the isolated rats persistently exhibited higher levels of miR-29 family members and miR-203. Our results confirmed that VEGFA is a direct target of these miRNAs, as both miR-29a,c and miR-203 strongly and specifically suppressed endogenous VEGFA expression in vitro. CONCLUSIONS: This study in rats demonstrates for the first time that social isolation delays oral mucosal healing, and suggests a potential role for healing-associated gene and miRNA interactions during this process via modulation of VEGF expression.

Objective. The chemokine receptor CXCR4 and its ligand CXCL12 have been suggested to play important roles in the initiation or progression of cancers. The goal of the present study was to investigate alterations of CXCL12/CXCR4 in oral premalignant lesions and oral squamous cell carcinoma (OSCC). Methods. In 13 normal oral epithelia, 24 dysplastic oral leukoplakia (OLK), and 40 OSCC specimens, expressions of CXCL12 and CXCR4 were evaluated by immunohistochemistry. Results. CXCR4 was expressed in 37.5% of OLK and 60% of OSCC. CXCL12 was detected in 50% of OLK and 62.5% of OSCC. In OLK, CXCR4 positive ratio showed no significant difference from normal epithelia, but the CXCL12 positive ratio was significantly higher. Significant relationship between CXCL12 and CXCR4 was found both in OLK and OSCC. Conclusion. Our results indicated that CXCL12/CXCR4 axis may play roles from early steps of oral malignant transformation and contribute to the progress of oral carcinogenesis.

Several studies have indicated that PAPSS2 (3'-phosphoadenosine-5'-phosphosulfate synthetase 2) activity is important to normal skeletal development. Mouse PAPSS2 is predominantly expressed during the formation of the skeleton and cartilaginous elements of the mouse embryo and in newborn mice. However, the role and mechanism of PAPSS2 in bone formation remains largely unidentified. By analyzing the expression pattern of the PAPSS2 gene, we have found that PAPSS2 is expressed in bone tissue and bone formation. PAPSS2 transcripts increase during osteoblast differentiation and are in less level in RANKL-induced osteoclast like cells. By using lentivirus-mediated RNA interference (RNAi) technology, we knocked down PAPSS2 expression in MC3T3-E1 osteoblast. Silencing of PAPSS2 expression significantly decreases ALP activity and cell mineralization, inhibits expression of osteoblast marker osteopontin (OPN) and collagen I. Conversely, overexpression of PAPSS2 promotes the MC3T3-E1 to differentiate into osteoblast and mineralization. Moreover, compared to that in the control cells, the mRNA level and protein expression of phosphorylated Smad 2/3, which is a key transcriptional factor in the Smad osteoblast differentiation pathway, showed significant decreases in PAPSS2-silenced cells and increases in PAPSS2-overexpression cells. These results suggest that PAPSS2 might regulate osteoblast ALP activity and cell mineralization, probably through Smads signal pathways.

Purpose: Patients with acute hip fractures who are on maintenance warfarin for anticoagulation present a significant challenge and their management remains controversial. The purpose of this study was to assess thromboembolic and systemic complications associated with pharmacological reversal of warfarin-associated coagulopathy in a population of geriatric patients with hip fractures. Methods: This retrospective cohort study identified patients with operative hip fractures on oral warfarin therapy who had an international normalized ratio (INR) >1.50 on admission (N = 93) approximately over a 13-year span. The control group consisted of patients whose warfarin was held upon admission without further intervention preoperatively (n = 23). The treatment group consisted of patients who underwent pharmacologic reversal of elevated INR with vitamin K and/or fresh frozen plasma (FFP) in addition to holding warfarin (n = 70). Primary outcomes included thromboembolic and other complications as well as mortality within 3 months of presentation. Time to surgery was a secondary outcome. Results: The 3-month mortality rate was 4% in the pharmacological intervention group and 17% in the watch-and-wait group; this difference trended toward statistical significance ( P = .06). There were no significant differences in the likelihoods of other thromboembolic or nonthromboembolic complications between groups. While the difference in mean time to surgery was not significantly different overall between groups, this difference was significant in a subgroup of patients with higher baseline INRs (n = 46, INR >2.17), with a mean difference of 4.0 fewer days until surgery in the pharmacological intervention group ( P < .01). Conclusions: Pharmacological reversal of warfarin-associated coagulopathy with a combination of vitamin K and FFP appears to be a safe way to optimize patients for operative fixation of hip fractures and is associated with a shorter delay to surgery in patients with more elevated INRs preoperatively. Level of evidence: retrospective cohort study (level III).