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Nitrogen (N) and phosphorus (P) nutrients have been regularly applied to improve productivity in intensively managed and short-rotation forest plantations in subtropical China. Under the constraint of the national policy of “carbon neutrality”, it is necessary to determine the rational fertilization options by considering both forest productivity and soil CO2 emissions. Past worldwide studies have shown varied responses of forest soil heterotrophic respiration and CO2 emissions to N and P additions. This study designed six treatments with N additions (high level: 15 g N/m2, HN), P (low: 5 g P/m2, LP; high: 15 g P/m2, HP), and their interactions (HNLP and HNHP) to explore the effects of N and P additions on soil CO2 emissions in a P-limited and N-rich Chinese fir plantation (Cunninghamia lanceolata), and we identified the underlying controls using the structural equation model (SEM). The results indicated that LP, HNLP, and HNHP treatments significantly increased soil CO2 emissions in the first four months after treatment and the effects leveled since then. The balance between N and P inputs affected the responses of soil CO2 emissions to P additions. A low P addition significantly increased tree productivity, but the promoting effect gradually declined and was no longer significant after 3 years. Other treatments did not significantly affect tree productivity. The SEM analysis revealed that the promoting effects of P additions on CO2 emission were mainly due to their effects on increasing soil water-soluble organic carbon content and reducing microbial biomass nitrogen content. Considering both soil respiration and tree productivity, this study suggested that LP treatment can effectively balance the N and P nutrients and, in the meantime, maintain relatively low greenhouse gas emissions; thus a low P application level is suggested for N-rich Chinese fir plantations.

Hypersharpening (namely, hyperspectral (HS) and multispectral (MS) image fusion) aims at enhancing the spatial resolution of HS image via an auxiliary higher resolution MS image. Currently, numerous hypersharpening methods are proposed successively, among which the unmixing-based approaches have been widely researched and demonstrated their effectiveness in the spectral fidelity aspect. However, existing unmixing-based fusion methods substantially employ mathematical techniques to solve the spectral mixture model, without taking full advantage of the collaborative spatial-spectral information that is usually helpful for abundance estimation improvement. To overcome this drawback, in this article, a novel unmixing-based HS and MS image fusion method, via a convolutional neural network (CNN), is proposed to promote spectral fidelity. The main idea of this work is to use CNN to fully explore the spatial information and the spectral information of both HS and MS images simultaneously, thereby enhancing the accuracy of estimating the abundance maps. Experiments on four simulated and real remote sensing data sets demonstrate that the proposed method is beneficial to the spectral fidelity of the fused images compared with some state-of-the-art algorithms. Meanwhile, it is also easy to implement and has a certain advantage in running time.

Over the past few years, convolutional neural network (CNN) has been broadly adopted in remote sensing (RS) imagery processing areas due to its impressive capabilities in feature extraction. Nevertheless, it is still a challenge for CNN-based hyperspectral image (HSI) classification methods to extract more effective spectral-spatial features considering all spectral bands. Driven by this issue, we propose a novel approach to cope with the HSI classification task, referring to the multilevel joint feature extraction network. The proposed network makes full use of the information on each channel of HSI and transforms it into valid channel-wised spatial features through a designed convolution process. Moreover, these feature maps form global attention details to guide the extraction of spectral-spatial features, which are taken to the next level for further feature mining. Then, the features obtained at different levels are integrated for ground object classification. In contrast with several state-of-the-art HSI classification methods on four public datasets, experimental results demonstrate the effectiveness and remarkable feature extraction capability of our proposed approach.

Super-resolution (SR) technology has emerged as an effective tool for image analysis and interpretation. However, single hyperspectral (HS) image SR remains challenging, due to the high spectral dimensionality and lack of available high-resolution information of auxiliary sources. To fully exploit the spectral and spatial characteristics, in this paper, a novel single HS image SR approach is proposed based on a spatial correlation-regularized unmixing convolutional neural network (CNN). The proposed approach takes advantage of a CNN to explore the collaborative spatial and spectral information of an HS image and infer the high-resolution abundance maps, thereby reconstructing the anticipated high-resolution HS image via the linear spectral mixture model. Moreover, a dual-branch architecture network and spatial spread transform function are employed to characterize the spatial correlation between the high- and low-resolution HS images, aiming at promoting the fidelity of the super-resolved image. Experiments on three public remote sensing HS images demonstrate the feasibility and superiority in terms of spectral fidelity, compared with some state-of-the-art HS image super-resolution methods.

Owing to the limits of incident energy and hardware system, hyperspectral (HS) images always suffer from low spatial resolution, compared with multispectral (MS) or panchromatic (PAN) images. Therefore, image fusion has emerged as a useful technology that is able to combine the characteristics of high spectral and spatial resolutions of HS and PAN/MS images. In this paper, a novel HS and PAN image fusion method based on convolutional neural network (CNN) is proposed. The proposed method incorporates the ideas of both hyper-sharpening and MS pan-sharpening techniques, thereby employing a two-stage cascaded CNN to reconstruct the anticipated high-resolution HS image. Technically, the proposed CNN architecture consists of two sub-networks, the detail injection sub-network and unmixing sub-network. The former aims at producing a latent high-resolution MS image, whereas the latter estimates the desired high-resolution abundance maps by exploring the spatial and spectral information of both HS and MS images. Moreover, two model-training fashions are presented in this paper for the sake of effectively training our network. Experiments on simulated and real remote sensing data demonstrate that the proposed method can improve the spatial resolution and spectral fidelity of HS image, and achieve better performance than some state-of-the-art HS pan-sharpening algorithms.

Extruded profiles/sections are increasingly used in the transport industry for lightweight structures. In this paper, a wide thin-ribbed aluminium profile with asymmetric Z-shape, was manufactured by a novel sideways extrusion process proposed by the authors. A comparative study was conducted by utilising the direct/forward extrusion process at the same extrusion temperature and speed, in which the different process mechanics, resulting microstructures and mechanical properties of profiles have been investigated by experiments and finite element modelling. It was revealed that, compared with sideways extrusion, although the design of a die pocket in forward extrusion induces preform and avoids the use of the large-diameter billet and extrusion container/press needed for extruding wide profiles, it requires a greater extrusion force due to work-piece upsetting necessary to fill the die pocket and leads to a lower effective strain in the profile rib. EBSD characterisation of the regions with an equal effective strain indicated that an increased shear strain is more efficient for obtaining fine grains with a higher average misorientation angle. In the same region of the profile rib made from the two different processes, sideways extrusion results in greater grain refinement due to greater effective strains, and a slightly greater texture intensity was found due to the intensive shear deformation. Tensile tests on formed profiles revealed that sideways extrusion leads to a higher yield strength (YS) and ultimate tensile strength (UTS) but a relatively lower elongation to failure, due to the combined effects of grain refinement, GND and texture intensity enhancement. Compared with the billet, the profile formed by forward and sideways extrusion has a YS increased by about 60% and 79% respectively, and an UTS increased by about 74% and 80% respectively in the extrusion direction, demonstrating an advantage of the sideways extrusion process in improving material strength under the same extrusion condition.

Hyperspectral (HS) image sharpening (namely hyper sharpening) with an auxiliary sensor, such as multispectral (MS) or panchromatic sensor, has attracted a great deal of attention for the past decade. A number of hyper-sharpening techniques, aiming at enhancing the spatial resolution of HS images, have been developed and demonstrated their effectiveness especially on synthetic or simulated data. Nevertheless, since the differences between different remote sensing systems or imaging conditions are complicate, it results in a serious spectral distortion when applying on real remote sensing data acquired by different sensors under different acquisition times or conditions. Unfortunately, very few works have considered this issue. In this paper, a new hyper-sharpening framework based on spectral modulation is proposed to better preserve spectral information when fusing with MS data acquired by a different sensor. The goal of this paper is to generate an adjusted MS image that would have been observed under the same imaging conditions with the corresponding HS sensor. Two approaches, originating in MS pan-sharpening field, are introduced as examples under this framework, namely high-pass details injection model and band-dependent spatial-detail model. Experiments on three HS and MS datasets acquired by different platforms demonstrate that the proposed framework is beneficial to the spectral fidelity of the fused image compared with some state-of-the-art hyper-sharpening techniques. Meanwhile, it is also easy to implement and has a certain advantage in enhancing the spatial details.

The exploration of the moon and the construction of the manned lunar outpost are the important parts of the deep space exploration. The continuous supply of thermal energy and power for deep space explorers and scientific equipment is a crucial issue to accomplish manned lunar missions. For most locations on the lunar surface, darkness lasts for periods of about 350 hours, so it is a great challenge for the solar photovoltaic cells and radioisotope thermoelectric generators to launch too much material from Earth. In the mission of manned deep space exploration, it is very necessary to utilize in situ resource effectively and sufficiently to reduce the hardware must be brought from Earth and to meet the requirement of energy and life support system. This paper describes an exergy analysis of a lunar based solar thermal power system using the method of finite-time thermodynamics. The calculations indicate that the system can provide the desired energy for the equipment. The aim of this article is to provide the basis for the design of a solar-powered Stirling engine using thermal energy from the processed lunar regolith.

Despite the extensive attention to the role of entrepreneurs’ business or political ties, few studies have distinguished the basis of those social ties. The aim of this study is to explore the different roles of the entrepreneurs’ personalized and formal social ties on the firms’ innovation performance. Based on renqing and formal rules, this study extends the social ties’ typology into four categories, namely, transactional business ties, transactional political ties, guanxi business ties, and guanxi political ties. Using data collected from 209 Chinese firms, we further identify the distinctive contributions of the different ties on the entrepreneurial firm’s innovation performance under different institutional environments and entrepreneurs’ survival pressure. This paper will help researchers and managers better understand the function of social ties in innovation in emerging markets, such as China.

A novel process for fabricating cross-sectional shapes of curved profiles in industrial applications, two-billet differential velocity sideways extrusion (DVSE), is proposed in this study. The feasibility of the process is demonstrated by fabricating solid bars of the aluminium alloy AA1070 through the solid-state welding of two billets at elevated temperature. Microstructural examination has shown that the weld formed between the two billets consists of an unsound area in the dead metal zone within the die and a sound bonding area in the welding zone. Along the welding path, the effective and normal strains gradually increase while the shear strain decreases, leading to the transformation of grains from equiaxed to bamboo-like structures and increases in the hardness, average grain size, and fraction of low angle grain boundaries. The shear strength of the welded extrudate is larger than that of the material without welding. The effective strain in the welding zone is larger than that in other zones. Increasing the temperature or speed of extrusion decreases the unsound bonding area length and the shearing angle, thus improving the uniformity of distribution of the shear strain. The grain diameter is refined from ∼500 μm in the initial billet to ∼47 μm in the welding zone of the extrudate formed at 0.05 mm/s and 450 ℃. The hardness of the extrudate formed at 400 °C and 0.1 mm/s is ∼19 % larger than that of the initial billet, and is decreased by decreasing the extrusion speed or increasing the temperature.

Increased nitrogen (N) inputs in subtropical forest ecosystems were widely reported. Extra N additions were reported to cause nutrient imbalance and phosphorus (P) limitation in many tropical and subtropical forests, and further result in changes in soil nitrous oxide (N2O) and methane (CH4) fluxes. Here, we conducted experiments with N (high N addition: 15 g N/m2, HN), P (low: 5 g P/m2, LP; high: 15 g P/m2, HP) and their interactive (HNLP and HNHP) treatments to investigate how N and P additions affected CH4 and N2O exchanges in an N-rich Chinese fir plantation (Cunninghamia lanceolata), and further explored the underlying mechanisms through the structural equation model (SEM) analysis. The results indicated that N addition alone (HN) significantly (p < 0.05) increased the soil N2O emissions by 30.15% and 80.47% over annual and 4-month periods, mainly owing to the elevated NH4+-N content. P addition alone (LP and HP) did not significantly affect the soil N2O emissions as compared with the control. The SEM analysis indicated that increased N2O emissions under N addition were primarily explained by the increase in available N and contributed more to the stimulated NH4+-N contents. N and P interactive additions slightly (not significant) stimulated the N2O emissions as compared with that under the N addition alone treatment. High-dose P addition significantly increased the soil CH4 uptake by 15.80% and 16.23% under the HP and HNHP treatments, respectively, while N addition alone and low P addition (LP and HNLP) did not significantly affect CH4 uptake as compared with the control. The increased water-soluble organic carbon and microbial biomass carbon explained the increased CH4 uptake under high P addition. The fertilization effects on N2O emissions and CH4 uptake mainly occurred in the first 4 months and diminished after that. Our results suggested that the direction, magnitude and timing of the N and P addition effects on N2O emissions and CH4 uptake would depend on the soil nutrient status and plant–microbial competition for N and P in subtropical forests.

Differential velocity sideway extrusion (DVSE) process is a cutting-edge technology to manufacture curved profiles with solid or hollow cross-sections. Extrusion welding is inevitable to form hollow cross-section profiles during DVSE. In the present work, two billets (AA1070) were welded into a bar in the chamber of an extrusion die through DVSE. The material flow behaviour, grain structure and its development in the extruded bar were studied. Based on material flow behaviour, the flow plane of material in the chamber of extrusion die can be divided into metal dead zone (MDZ), shearing intensive zone (SIZ), and metal flow zone (MFZ, including the welding zone). A sound weld without any bonding interface can be obtained by DVSE welding at 500 ℃ and 0.1 mm/s. Before material arrives at the exit of extrusion die, banded structures form along the metal flow direction with the increase of deformation and the mean grain size continually decreases due to dynamic recrystallisation (DRX). Grains significantly grow after exiting from the extrusion die.

The alkali metal thermoelectric converter (AMTEC) is a regenerative concentration cell for direct conversion of heat to electrical energy. Optimization of the components in AMTECs has been gained wide interest to improve power output and cell efficiency. A lumped thermal-electrochemical model has been developed in this work based on some previous efforts by Tournier et al. (1997). The main contribution of the present model is to simplify the calculation of radiation heat exchange by rendering the BASE, the condenser and the cell walls as a system of three closed-surfaces. The net radiative heat loss from the BASE is determined using a network method of radiation. For model validation purposes, the lumped model is applied to a PX-3A type cell. Good agreements have been obtained between numerical results and experimental data on variations of voltage, current, power output and cell efficiency within a wide range of external loads. Based on the numerical results, the role and separate influence of each component are quantitatively analyzed, including temperature levels for hot and cold ends, BASE properties, electrode materials, heat reduction methods and conductor leads. Optimum parameters are suggested in the analyses. With the recent advances in BASE and electrode materials, an integrated optimization is made to the AMTEC aiming for extra-terrestrial application. In the new module, the surface area of electrodes is increased, new electrodes materials are used and thermal radiation losses are minimized. With stable parameters, the peak power of the cell has been over 8.0 We. The stable voltage is over 3.0 V when RL > 1.2 Ω and the cell efficiency is over 20% when RL is within 1.2–4.0 Ω.

// Lu Ding 1 , Qifeng Jiang 1 , Guang Li 1 , Jia Shen 1 , Jiayin Du 1 , Xiaochen Lu 1 and Xingliang Xiong 1 1 Department of Medical Informatics, Chongqing Medical University, Chongqing, 400016, China Correspondence to: Xingliang Xiong, email: xlxiong@cqmu.edu.cn Keywords: cancer risk, toll-like receptor, TLR4, SNP, meta-analysis Received: July 18, 2017 Accepted: September 25, 2017 Published: October 06, 2017 ABSTRACT Previous studies have explored the association between toll-like receptor 4 (TLR4) polymorphisms and risk of various cancers, but the results remained controversial. To obtain an assessment of the effect of TLR4 polymorphisms (rs4986790, rs4986791 and rs11536889) on cancer risk, fifty-five articles (containing 20107 cases and 28244 controls) were recruited for meta-analysis. Our result indicated that two Single Nucleotide Polymorphisms (SNP) in TLR4 were associated with decreased cancer risk for rs4986791: OR = 0.764, 95% CI: 0.652-0.894, P = 0.001 in allele model; OR = 0.769, 95%CI: 0.650-0.909, P = 0.002 in recessive model; OR = 0.505, 95% CI: 0.352-0.726, P = 0.000 in dominant model; for 11536889: OR = 0.927, 95% CI: 0.872–0.984, P = 0.013 in allele model; OR = 0.926, 95% CI: 0.862–0.944, P = 0.034 in recessive model. In terms of subgroup analyses sorted by ethnicity, only polymorphism of rs4986791 had a significant influence on decrease of cancer risk among both Caucasian and Asian populations. The findings suggested that TLR4 polymorphisms may serve as a genetic risk factor for cancers.

Agonistic encounters are powerful effectors of future behavior, and the ability to learn from this type of social challenge is an essential adaptive trait. We recently identified a conserved transcriptional program defining the response to social challenge across animal species, highly enriched in transcription factor (TF), energy metabolism, and developmental signaling genes. To understand the trajectory of this program and to uncover the most important regulatory influences controlling this response, we integrated gene expression data with the chromatin landscape in the hypothalamus, frontal cortex, and amygdala of socially challenged mice over time. The expression data revealed a complex spatiotemporal patterning of events starting with neural signaling molecules in the frontal cortex and ending in the modulation of developmental factors in the amygdala and hypothalamus, underpinned by a systems-wide shift in expression of energy metabolism-related genes. The transcriptional signals were correlated with significant shifts in chromatin accessibility and a network of challenge-associated TFs. Among these, the conserved metabolic and developmental regulator ESRRA was highlighted for an especially early and important regulatory role. Cell-type deconvolution analysis attributed the differential metabolic and developmental signals in this social context primarily to oligodendrocytes and neurons, respectively, and we show that ESRRA is expressed in both cell types. Localizing ESRRA binding sites in cortical chromatin, we show that this nuclear receptor binds both differentially expressed energy-related and neurodevelopmental TF genes. These data link metabolic and neurodevelopmental signaling to social challenge, and identify key regulatory drivers of this process with unprecedented tissue and temporal resolution.

In this paper, we propose a self-learning approach for remote sensing image classification. The main work of this paper aims at providing a new framework of semisupervised learning technique for multiple-source synergetic classification, thereby improving the classification accuracy under the condition of small samples. Considering the high spectral resolution of a hyperspectral (HS) image and the high spatial resolution of a panchromatic (PAN) image, the proposed approach combines image segmentation with an active learning algorithm and adopts a standard active learning method for a self-learning strategy, in which the learning algorithm automatically selects informative unlabeled samples by itself according to their collaborative spatial–spectral features and the predicted information of a spectral-based classifier. This way, no extra cost of human expertise is required for labeling the selected pixels when compared with conventional active learning methods. Experiments on three data sets, including HS and PAN images, indicate that our proposed approach has a great enhancement on overall classification accuracy compared with classical supervised algorithms and turns out to be a promising strategy in synergetic classification of HS and PAN images.

With the resolution improvement of the remote-sensing images, more details are shown clearly. The challenge that comes along is how to boost the relatively low classification accuracy caused by using pixel-based image classification approaches and low-level visual structure. The low-level features (LLF) may not well describe the image due to the semantic gap between low-level visual features and high-level semantics of images. The bag-of-visual-words (BOV) model which generates mid-level features was proposed to bridge the two levels. However, it generally neglects the context information between local patches. In this paper, an object-oriented semantic classification algorithm that combines BOV with the optimal segmentation scale is presented. In this algorithm, BOV addresses the problem of the representation of mid-level for scenes, while the optimal segmentation scale intends to overcome the defect of conventional BOV in lacking of relationship between image patches and to give more thorough description. The object-based BOV is presented to construct mid-level representations for object description instead of LLF, and histogram intersection kernel (HIK) is introduced in support vector machine (SVM) for classification. The experiments conducted on three datasets testify the superiority of the proposed algorithm.

In this paper, a detail-injection method based on a coupled convolutional neural network (CNN) is proposed for hyperspectral (HS) and multispectral (MS) image fusion with the goal of enhancing the spatial resolution of HS images. Owing to the excellent performance in spectral fidelity of the detail-injection model and the image spatial&ndash, spectral feature exploration ability of CNN, the proposed method utilizes a couple of CNN networks as the feature extraction method and learns details from the HS and MS images individually. By appending an additional convolutional layer, both the extracted features of two images are concatenated to predict the missing details of the anticipated HS image. Experiments on simulated and real HS and MS data show that compared with some state-of-the-art HS and MS image fusion methods, our proposed method achieves better fusion results, provides excellent spectrum preservation ability, and is easy to implement.

Gas-liquid separation under microgravity is a key scientific problem in space, which have wide application in future space systems. EHD has been proven an effective technique for enhancing two-phase separation by applying an electric field and induced electric forces to a dielectric fluid conveniently and adjustably. Although the electric effect on bubble dynamics of deformation and detachment are extensively studied recent years, the bubble motion behaviors which play an important role on phase separation under microgravity is seldom studied. In this paper, the motion behavior of a single air bubble surrounded by dielectric liquid CCl4 in a coaxial annular electrode electric field under microgravity is studied numerically to evaluate the potential phase separation applications under Microgravity. In the process of the numerical simulation, the Level Set (LS) method is employed to track the interface between the gas-liquid two phases, and a continuum surface force (CSF) model is used to calculate the surface tension force. Governing equations for the flow field and the electric field under microgravity are coupled numerically, which are solved by using an unstructured mesh system in the Cartesian coordinate system. Bubble motions including deformation and motion trajectory of the bubble, and flow patterns of the two-phase flow are payed close attention in this nonuniform electric field, where the underlying mechanism of EHD enhancement on phase separation is investigated. The simulation results indicate that the two-phase flow field and electric field interact and influence each other. The bubble would deform under the action of electric field force and move along the reduced direction of electric field, and the electric potential around the bubble would change compared with the initial state without the bubble in the nonuniform electric field under microgravity, which can greatly promote the gas-liquid two-phase separation in space.

The superheating induced overpressure is one of the key obstacles for long-endurance station-keeping of stratospheric aerostats. A novel stratospheric aerostat by utilizing the natural energy is presented and discussed in this paper. A thermo-mechanical dynamic model is established to analyze the altitude control performance of this novel aerostat. The simulation results show that the novel stratospheric aerostat can ascend to a high altitude about 25.8 km due to the combined heating effects of the solar radiation, the Earth albedo and the infrared radiation from the Earth’s surface and keeps at an altitude about 22 km by the infrared radiation from the Earth’s surface. In addition, the aerostat can be controlled within the desired altitude range by the simple open/close valve control strategy.

The ability to image the entire adult mouse heart at high resolution in 3-D would provide enormous advantages in the study of heart disease. However, a technique for imaging nuclear/cellular detail as well as the overall structure of the entire heart in 3-D with minimal effort is lacking. To solve this problem, we modified the benzyl alcohol:benzyl benzoate (BABB) clearing technique by labeling mouse hearts with periodic acid Schiff (PAS) stain. We then imaged the hearts with a combination of two-photon fluorescence microscopy and automated tile-scan imaging/stitching. Utilizing the differential spectral properties of PAS, we could identify muscle and nuclear compartments in the heart. We were also able to visualize the differences between a 3-month-old normal mouse heart and a mouse heart that had undergone heart failure due to the expression of cardiac myosin binding protein-C (cMyBP-C) gene mutation (t/t). Using 2-D and 3-D morphometric analysis, we found that the t/t heart had anomalous ventricular shape, volume, and wall thickness, as well as a disrupted sarcomere pattern. We further validated our approach using decellularized hearts that had been cultured with 3T3 fibroblasts, which were tracked using a nuclear label. We were able to detect the 3T3 cells inside the decellularized intact heart tissue, achieving nuclear/cellular resolution in 3-D. The combination of labeling, clearing, and two-photon microscopy together with tiling eliminates laborious and time-consuming physical sectioning, alignment, and 3-D reconstruction.

A decision-level-based synergetic classification method has been proposed to conduct land-cover classification for long-wave infrared (LWIR) and high-resolution visible (VIS) images in this paper. The problem of synergic classification is challenging, since we aim for classification map at the spatial resolution of the VIS image under different imaging modes. The proposed method consists of two stages, i.e., stage of classifications for LWIR hyperspectral (HS) and VIS images separately, and stage of decision-level fusion for both classification results. For LWIR HS image, we have proposed a new semisupervised feature extraction method named as semisupervised local discriminant analysis (SLDA) for SVM classification. In parallel, spatial features which have been extracted from the high-resolution VIS image are used to combine with the spectral features for classification. In the second stage, several common decision-level fusion rules have been employed to integrate both classification results. We also present a context-based opinion pools (CBP) strategy to enhance the classification accuracy. Experiments conducted on the dataset of 2014 IEEE GRSS Data Fusion Contest show the advantage of our proposed SLDA method for HS image, and the effect of spatial–spectral features for high-resolution VIS image. Especially, the presented synergic classification strategy for HS and VIS images has higher overall accuracy and better visual effect than those only using single source image and those compared fusion methods in the experiments.

In order to understand thermal characteristics of high altitude airships, the numerical simulation of convective-radiative coupled heat transfer performance at a certain time in a day is carried out using Ansys Fluent software. The governing equations of flow are using the compressible Reynolds averaged N-S equations and standard κ-ɛ turbulence model. A non-uniform temperature distribution boundary condition in the complex thermal environment and heat transfer mechanism is applied on the surface of high altitude airships based on user definition function (UDF) programming. The paper then simulates the external convection heat transfer characteristics at various flow conditions at 40 degrees north latitude at the altitude about 20 km at noon in the summer solstice. Finally, the corresponding calculation results of the surface temperature distribution, the flow field distribution and the convective heat flux distribution of airship envelope are presented, which are also analyzed in this paper.

The vertebrate T-box transcription factor gene Tbx18 performs a vital role in development of multiple organ systems. Tbx18 insufficiency manifests as recessive phenotypes in the upper urinary system, cardiac venous pole, inner ear, and axial skeleton; homozygous null mutant animals die perinatally. Here, we report a new regulatory mutation of Tbx18, a reciprocal translocation breaking 78kbp downstream of the gene. 12Gso homozygotes present urinary and vertebral defects very similar to those associated with Tbx18-null mutations, but 12Gso is clearly not a global null allele since homozygotes survive into adulthood. We show that 12Gso down-regulates Tbx18 expression in a manner that is both spatially- and temporally-specific; combined with other data, the mutation points particularly to the presence of an essential urogenital enhancer located near the translocation breakpoint site. In support of this hypothesis, we identify a distal enhancer element, ECR1, which is active in developing urogenital and other tissues; we propose that disruption of this element leads to premature loss of Tbx18 function in 12Gso mutant mice. These data reveal a long-range regulatory architecture extending far downstream of Tbx18, identify a novel and likely essential urogenital enhancer, and introduce a new tool for dissecting postnatal phenotypes associated with dysregulation of Tbx18.

While many vertebrate transcription factor (TF) families are conserved, the C2H2 zinc finger (ZNF) family stands out as a notable exception. In particular, novel ZNF gene types have arisen, duplicated, and diverged independently throughout evolution to yield many lineage-specific TF genes. This evolutionary dynamic not only raises many intriguing questions but also severely complicates identification of those ZNF genes that remain functionally conserved. To address this problem, we searched for vertebrate "DNA binding orthologs" by mining ZNF loci from eight sequenced genomes and then aligning the patterns of DNA-binding amino acids, or "fingerprints," extracted from the encoded ZNF motifs. Using this approach, we found hundreds of lineage-specific genes in each species and also hundreds of orthologous groups. Most groups of orthologs displayed some degree of fingerprint divergence between species, but 174 groups showed fingerprint patterns that have been very rigidly conserved. Focusing on the dynamic KRAB-ZNF subfamily--including nearly 400 human genes thought to possess potent KRAB-mediated epigenetic silencing activities--we found only three genes conserved between mammals and nonmammalian groups. These three genes, members of an ancient familial cluster, encode an unusual KRAB domain that functions as a transcriptional activator. Evolutionary analysis confirms the ancient provenance of this activating KRAB and reveals the independent expansion of KRAB-ZNFs in every vertebrate lineage. Most human ZNF genes, from the most deeply conserved to the primate-specific genes, are highly expressed in immune and reproductive tissues, indicating that they have been enlisted to regulate evolutionarily divergent biological traits.

The T-box transcription factor TBX18 is essential to mesenchymal cell differentiation in several tissues and Tbx18 loss-of-function results in dramatic organ malformations and perinatal lethality. Here we demonstrate for the first time that Tbx18 is required for the normal development of periductal smooth muscle stromal cells in prostate, particularly in the anterior lobe, with a clear impact on prostate health in adult mice. Prostate abnormalities are only subtly apparent in Tbx18 mutants at birth; to examine postnatal prostate development we utilized a relatively long-lived hypomorphic mutant and a novel conditional Tbx18 allele. Similar to the ureter, cells that fail to express Tbx18 do not condense normally into smooth muscle cells of the periductal prostatic stroma. However, in contrast to ureter, the periductal stromal cells in mutant prostate assume a hypertrophic, myofibroblastic state and the adjacent epithelium becomes grossly disorganized. To identify molecular events preceding the onset of this pathology, we compared gene expression in the urogenital sinus (UGS), from which the prostate develops, in Tbx18-null and wild type littermates at two embryonic stages. Genes that regulate cell proliferation, smooth muscle differentiation, prostate epithelium development, and inflammatory response were significantly dysregulated in the mutant urogenital sinus around the time that Tbx18 is first expressed in the wild type UGS, suggesting a direct role in regulating those genes. Together, these results argue that Tbx18 is essential to the differentiation and maintenance of the prostate periurethral mesenchyme and that it indirectly regulates epithelial differentiation through control of stromal-epithelial signaling.

BACKGROUND Cyclooxygenase-2 (COX-2) is an inducible enzyme that mediates the synthesis of prostaglandin, which plays an important role in the inflammation response. The overexpression of COX-2 in lung cancer has been found in several studies, suggesting that COX-2 contributes to carcinogenesis. There are many previous case-control studies focused on the association between COX-2 polymorphism and lung cancer risk, however, the conclusion remained controversial. OBJECTIVES We performed this meta-analysis to evaluate the association between COX-2 rs5275 and rs689466 polymorphism and susceptibility to lung cancer. METHODS A systematic literature research was conducted on PubMed, Embase, Cochrane Library, OVID, Web of Science, and Google Scholar up to November 30, 2017. The quality of studies was assessed by Newcastle-Ottawa scale. We combined odds ratios (ORs) and 95% confidence intervals (CIs) in 5 different genetic models for evaluation under a fixed-effect model or random-effect model. Subgroup analysis was performed according to source of control, ethnicity, pathological types, and smoking status. Sensitivity analysis and publication bias were also conducted. RESULTS Eventually, 14 eligible studies were included in our meta-analysis. We found rs5275 gene polymorphism decreased the risk of lung cancer under heterozygote model (OR: 0.91, 95% CI: 0.84-0.98, P = .02). COX-2 rs689466 gene polymorphism was also related to a significantly reduced risk under allele (OR: 0.88, 95% CI: 0.82-0.95, P = .001), homozygote (OR: 0.81, 95% CI: 0.68-0.95, P = .01), heterozygote (OR: 0.81, 95% CI: 0.72-0.91, P

Translocations have provided invaluable tools for identifying both cancer-linked genes and loci associated with heritable human diseases, but heritable human translocations are rare and few mouse models exist. Here we report progress on analysis of a collection of heritable translocations generated by treatment of mice with specific chemicals or radiation during late spermatogenic stages. The translocation mutants exhibit a range of visible phenotypes reflecting the disruption of coding sequences or the separation of genes from essential regulatory elements. The breakpoints of both radiation-induced and chemically induced mutations in these mice are remarkably clean, with very short deletions, duplications, or inversions in some cases, and ligation mediated by microhomology, suggesting nonhomologous end joining as the major path of repair. These mutations provide new tools for the discovery of novel genes and regulatory elements linked to human developmental disorders and new clues to the molecular basis of human genetic disease.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) equipped with a gold ion gun was used to image mouse embryo sections and differentiate tissue types (brain, spinal cord, skull, rib, heart and liver). Embryos were paraffin-embedded and then deparaffinized. The robustness and repeatability of the method was determined by analyzing ten tissue slices from three different embryos over a period of several weeks. Using principal component analysis (PCA) to reduce the spectral data generated by ToF-SIMS, histopathologically identified tissue types of the mouse embryos can be differentiated based on the characteristic differences in their mass spectra. These results demonstrate the ability of ToF-SIMS to determine subtle chemical differences even in fixed histological specimens.

YY2 was originally identified due to its unusual similarity to the evolutionarily well-conserved zinc finger gene YY1. In this study, we have determined the evolutionary origin and conservation of YY2 using comparative genomic approaches. Our results indicate that YY2 is a retroposed copy of YY1 that has been inserted into another gene locus named Mbtps2 (membrane-bound transcription factor protease site 2). This retroposition is estimated to have occurred after the divergence of placental mammals from other vertebrates based on the detection of YY2 only in the placental mammals. The N- and C-terminal regions of YY2 have evolved under different selection pressures. The N-terminal region has evolved at a very fast pace with very limited functional constraints, whereas the DNA-binding, C-terminal region still maintains a sequence structure very similar to that of YY1 and is also well conserved among placental mammals. In situ hybridizations using different adult mouse tissues indicate that mouse YY2 is expressed at relatively low levels in Purkinje and granular cells of cerebellum and in neuronal cells of cerebrum, but at very high levels in testis. The expression levels of YY2 are much lower than those of YY1, but the overall spatial expression patterns are similar to those of Mbtps2, suggesting a possible shared transcriptional control between YY2 and Mbtps2. Taken together, the formation and evolution of YY2 represent a very unusual case where a transcription factor was first retroposed into another gene locus encoding a protease and survived with different selection schemes and expression patterns.

In the course of large-scale mutagenesis studies, we discovered a mutant that provides a new mouse model for human autosomal recessive polycystic kidney disease. Animals homozygous for this mutation, T(2;10)67Gso, present evidence of grossly cystic renal and hepatic tissue at birth and a limited survival time of 3-4 days. The recessively expressed phenotype is associated with inheritance of a reciprocal translocation involving mouse chromosomes 2 and 10. Here we describe the pathology and phenotype of this new mutation. The mapping of the chromosomal breakpoint to the 1.0-cM critical region defined for another mouse autosomal recessive polycystic kidney disease model, juvenile congenital polycystic kidney disease (jcpk), led us to undertake the complementation testing that confirmed T(2;10)67Gso and jcpk are allelic. Because of the strong resemblance between the phenotype associated with these mouse mutations and early childhood polycystic kidney disease, and because of advantages offered by reciprocal translocations for gene mapping and cloning, T(2;10)67Gso should prove a valuable asset for studies concerning this fatal disease.

Certain complex phenotypes appear repeatedly across diverse species due to processes of evolutionary conservation and convergence. In some contexts like developmental body patterning, there is increased appreciation that common molecular mechanisms underlie common phenotypes; these molecular mechanisms include highly conserved genes and networks that may be modified by lineage-specific mutations. However, the existence of deeply conserved mechanisms for social behaviors has not yet been demonstrated. We used a comparative genomics approach to determine whether shared neuromolecular mechanisms could underlie behavioral response to territory intrusion across species spanning a broad phylogenetic range: house mouse (Mus musculus), stickleback fish (Gasterosteus aculeatus), and honey bee (Apis mellifera). Territory intrusion modulated similar brain functional processes in each species, including those associated with hormone-mediated signal transduction and neurodevelopment. Changes in chromosome organization and energy metabolism appear to be core, conserved processes involved in the response to territory intrusion. We also found that several homologous transcription factors that are typically associated with neural development were modulated across all three species, suggesting that shared neuronal effects may involve transcriptional cascades of evolutionarily conserved genes. Furthermore, immunohistochemical analyses of a subset of these transcription factors in mouse again implicated modulation of energy metabolism in the behavioral response. These results provide support for conserved genetic “toolkits” that are used in independent evolutions of the response to social challenge in diverse taxa.

Although the two alleles of most mammalian autosomal genes are functionally equivalent, the maternal and paternal copies of a subset of genes are distinguished by genomic imprinting, a mechanism by which one allele is epigenetically modified and repressed, depending upon parental origin. The epigenetic modification that determines imprinting is yet to be defined, but several lines of evidence strongly suggest that differences in DNA methylation and chromatin structure may be part of the molecular mechanism (Tilghman 1999). About 30 different imprinted genes have been isolated from human and mouse DNA, and more imprinted genes are predicted to be present in mammalian genomes (Barlow 1997; Morrison and Reeve 1998). The imprinted genes that have been described to date are clustered in discrete chromosomal regions, and the clustering of those genes is conserved in mammals (Barlow 1995; Bartolomei and Tilghman 1997). These data have been interpreted to imply that genome imprinting is a long-range mechanism that controls allele-specific transcription of multiple genes within a defined chromosomal region (Nicholls 1994; Dittrich et al. 1996; Tilghman et al. 1998, 1999). Imprinted genes exhibit several unique features in addition to parent-of-origin-specific monoallelic expression and differential methylation. The known imprinted genes generally are expressed at early stages of development, and many encode proteins with functions related to embryonic growth (Tilghman 1999). Recent studies also suggest the involvement of imprinted genes in controlling the parental caring behavior of mammals (Lefebvre et al. 1998; Li et al. 1999). Several imprinted genes such as UBE3A (Rougeulle et al. 1998), IGF2 (Moore et al. 1997), ZNF127 (Jong et al. 1999), and IGF2R (Wutz et al. 1997) display bidirectional transcription, producing both sense and antisense transcripts. A number of imprinted genes including H19 and IPW are expressed without any coding capability; the final products of these genes are RNAs rather than proteins (Bartolomei and Tilghman 1997). Imprinted genes also tend to be comosed of relatively small numbers of exons and to contain smaller introns than nonimprinted genes (Hurst et al. 1996), although there are some notable exceptions (e.g., KvLQT1; Lee et al. 1997). Early mouse genetic studies with translocation mutant mice predicted the presence of nine different imprinted domains distributed onto seven chromosomes (Beechey and Cattanach 1996). The chromosomal locations of most imprinted genes, in fact, are consistent with this initial prediction (Imprinting Map; http://www.mgu.har.mrc.ac.uk/imprinting/imptables.html#impmaps). Mouse chromosome 7 (Mmu7) was predicted in these early studies to contain three different imprinted domains, located in centromeric, central, and distal regions (Searle and Beechey 1990). The central and distal regions of Mmu7 are syntenically homologous to intervals of human chromosome 15q13-11 and 11p15, respectively, that contain genes associated with two imprinting genetic disorders—Prader–Willi/Angelman (Nicholls et al. 1998) and Beckwith–Wiedemann syndromes (Reik and Maher 1997). Each of these domains contains several imprinted genes whose order, sequence, and imprinting status are highly conserved in humans and mice. Until recently, only one imprinted gene, Peg3 (paternally expressed gene 3), had been localized to the centromeric imprinted domain of Mmu7 (Kuroiwa et al. 1996) and the homologous region of human chromosome 19q13.4 (Kim et al. 1997a). We exploited the well-developed physical map surrounding human PEG3 and the known conservation of this interval in humans and mice to identify a second mouse-imprinted gene, Zim1 (imprinted zinc-finger gene 1), located downstream of Peg3 (Kim et al. 1999). More recent studies identified a related and homologously positioned human zinc-finger gene, ZIM2, and showed that the gene shares seven 5′-exons with PEG3, a feature that distinguishes this pair of human genes from their closest murine counterparts (Kim et al. 2000). The significant divergence of Zim1 and ZIM2 gene organization and amino acid sequence suggests that the region surrounding PEG3 has undergone significant changes during the course of mammalian evolution. Through analysis of clone contigs spanning homologous segments of Mmu7 and sequenced regions of human 19q13.4, we have isolated and characterized another novel mouse gene, Usp29 (ubiquitin-specific processing protease 29) and have identified its human counterpart. Our analyses show that Usp29 is also imprinted and is expressed mainly from the paternal allele during embryogenesis and in adult brain. The sequence of a full-length 7.6-kb mouse cDNA clone and human coding sequences indicate that Usp29 encodes a novel ubiquitin-specific processing protease, and together with Ube3a may represent a second imprinted gene involved in the ubiquitination pathway.