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In private toll roads, some elements of the private operator’s performance are noncontractible. As a result, the government cannot motivate the private operator to improve them through a formal contract but through a self-enforcing contract that both parties are unwilling to deviate unilaterally. In this paper, we use noncontractible service quality to capture these performance elements. By employing a relational contract approach, we aim to investigate the optimal subsidy plan to provide incentives for quality improvement. We show that government subsidy is feasible in quality improvement when the discount factor is sufficiently high and marginal cost of public funds is sufficiently small. Under feasible government subsidy, we have demonstrated the optimal subsidy plans in different scenarios. Moreover, some comparative statics are presented. Based on the derived subsidy plans, we further investigate the optimal toll price. We find that the optimal toll price generates zero surplus for the private operator and positive surplus for consumers. We then make two extensions of our model to re-investigate the government’s optimal decisions on subsidy plan and toll price when her decision sequence is changed and when government compensation is present upon termination of the relationship. Some implications for practice have been derived from our model results.

The CaO-B2O3-SiO2 glass ceramics system with four different boron contents (14 wt. %, 16.4 wt. %, 18.6 wt. %, 21 wt. %) were prepared under 900oC. The properties and microstructures are characterized by Differential Scanning Calorimeter (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The effects of boron contents on the composition of crystalline phases and the properties of CaO-B2O3-SiO2 glass ceramics system were studied. The results show that when the molar ratio of CaO/SiO2 is 1.06, as the content of B2O3 increases, the major crystalline phases experiences the transformation from CaSiO3 to CaB2O4 and the content of α-SiO2 crystalline phase decreases, and the dielectric constant increases firstly but it decreases after the content of B2O3 reaches to 18.6 wt. %, while the dielectric loss tgδ of decreases gradually with the addition of boron content. When the content of B2O3 is 16.4 wt. %, the CaO-B2O3-SiO2 glass ceramics with a bulk density of 2.47 g/cm3 exhibits good dielectric properties (1 MHz): εr=6.03, tgδ=3.49×10-3.

Increasing evidence indicates that dysregulation of microRNAs (miRNAs) plays critical roles in malignant transformation and tumor progression. In this study, in order to investigate the association of miR-138 with breast cancer we investigated the role of miR-138 in breast cancer metastasis. Levels of miR-138 were determined by qRT-PCR in 45 breast cancer samples. Cell migration and invasion assays were performed in a stably expressing miRNA-138 breast cancer cell line established using a lentivirus expression system. Epithelial-mesenchymal transition (EMT) was evaluated using qRT-PCR and Western Blots to detect epithelial marker E-cadherin and mesenchymal marker, vimentin. Luciferase reporter assays were used to identify downstream targets and biological function of miR-138. Breast cancer tissues had significantly lower expression of miR-138 compared to non-tumor tissues. Low miR-138 levels were associated with lymph node metastasis and invasion. miR-138 overexpression inhibited metastasis of breast cancer cells. miR-138 overexpression also down-regulated vimentin expression and upregulated E-cadherin expression, suggesting that miR-138 inhibited EMT. Our results support the involvement of miR-138 in breast tumorigenesis, especially lymph node metastasis. We propose that miR-138 might be used as therapeutic agent for breast cancer.

Marattialeans were the most species-rich fern group in the Lopingian (late Permian) Cathaysian floras in the South China Block. However, most previous studies on marattialean ferns focused on their vegetative morphology; in contrast, their reproductive biology has rarely been examined. New compression materials of Zhutheca densata (Gu et Zhi) Liu, Li et Hilton from the Lopingian Xuanwei Formation in Qujing City, Yunnan Province, Southwest China, were studied and provide additional micromorphological and ultrastructural details about the reproductive organs of this marattialean plant. Reproductive organs of the Z. densata plant are characterized by radially symmetrical synangia in two or three rows on each side of the midvein, four to six exannulate sporangia laterally fused in a synangium, sporangial walls comprising three to four layers of cells, and monolete Laevigatosporites/Latosporites-type in situ spores. The spatiotemporal distribution of marattialean reproductive organs was analyzed based on a thorough comparison of 29 genera recorded in upper Paleozoic strata. Our analysis indicated that, during the Pennsylvanian and Permian periods, marattialeans with radially symmetrical synangia notably decreased in both diversification and distribution; in contrast, marattialeans with bilaterally symmetrical synangia notably increased in both diversification and distribution. After the Lopingian, marattialeans with bilaterally symmetrical synangia gradually became predominant in terms of their diversification and geographic distribution. Our study sheds new light on the evolution of marattialeans.

The Permian–Triassic transition is concerned with a critical time interval during the evolutionary history of terrestrial ecosystems. However, the ecological underpinnings of terrestrial ecosystems during this time interval are poorly understood due to an impoverished fossil record. One of the more understudied episodes in the history of life is the ecological state of terrestrial ecosystems immediately before the Permian–Triassic ecological crisis. We address this issue by a quantitative study of a floral assemblage and its herbivorous insect damage based on 1086 plant specimens from the uppermost Permian of Southwest China. This bulk flora comprises 25 genera and 36 species of plants representing a typical, tropical rainforest vegetation of the upper Permian. We record 171 insect damage occurrences belonging to 24 distinctive damage types (DTs) from six functional feeding groups that were recognised in the flora. Statistical analyses of the occurrence, richness, diversity and frequency of DTs reveal that gigantopterids are the principal host plants for insect herbivores in the flora. Compared with other late Permian floras, a significant distinction of the insect damage spectrum can be recognised palaeolatitudinally based on the global position of phytogeographic regions. Despite the different, major targeted plant hosts in these floras, the richness and diversity of insect DTs and their herbivory levels from mid- to high latitudinal floras are remarkably lower than those of low latitudinal to equatorial floras. Our study indicates that terrestrial ecosystems from lower latitudes have higher levels of ecological complexity, and a distinct latitudinal gradient that probably was well established in terrestrial ecosystems during the late Permian. This assessment provides the first comprehensive overview of the ecological relationships among plants and insects, as well as their representation in terrestrial ecosystems of the late Paleozoic Cathaysia Flora.

The end-Permian mass extinction is the greatest biotic crisis in Earth history causing the extinction of a large number of marine and terrestrial animals globally. However, how land plants responded to the catastrophe remains controversial. The successive plant-bearing beds in China provide a unique window into the great vegetation change through the critical Permian–Triassic time interval. A notable monospecific vegetation comprising a new isoetalean, Tomiostrobus sinensis Feng, is documented from the lowermost part of the coastal Kayitou Formation in Southwest China. The new plant is a diminutive, heterosporous lycophyte, which formed ground-covering communities infringing the oligotrophic lakes along coastal regions. The apparent occurrence of T. sinensis immediately above the uppermost coal bed demonstrates that the enigmatic gigantopterid-dominated rainforest ecosystem suddenly collapsed and was replaced by the isoetalean-dominated herbaceous vegetation in the tropics of the eastern Tethys. Our study indicates that the magnitude of vegetation response to the end-Permian mass extinction in different palaeophytogeographic regions is probably largely affected by the latitudinal gradients of biodiversity and ecological stress. Because of the complexity of local palaeoenvironmental, palaeoclimatic and palaeotopographic conditions, it is unlikely that a unified global pattern and timing of land plant response to the end-Permian mass extinction can be obtained.

In the early termination of public-private partnership (PPP) projects, compensation is considered a core issue that greatly affects the interests of the government and the private sector. To address the early termination that is frequently caused by government default or voluntary buyback, this paper proposes an ex-ante compensation mechanism using the cumulative probability that a given demand could be realized to determine early termination compensation under demand uncertainty. By splitting the compensation into two parts, the base compensation could be the minimum compensation for the private sector, while the additional compensation is considered a reasonable allocation of future booming demand. The predetermined compensation criterion ensures a smooth transfer of the early terminated project, which not only benefits the government from being overcharged, but also enables the private sector to gain a reasonable compensation for the remaining concession period.

An exceptionally well-preserved wood, Ningxiaites shitanjingensis sp. nov., is described from the uppermost Permian Sunjiagou Formation of Northwest China providing new evidence for plant diversity and paleoecological features of the Cathaysian Flora. The new plant is characterized by a eustelic vascular system with thick pycnoxylic woody cylinder. The cylindrical pith is solid and parenchymatous, surrounded by numerous, discrete endarch primary xylem strands and monarch leaf traces. The wood is especially distinctive by the expanded rays at the pith periphery and the pitted tangential walls of ray cells. The tracheids in the primary xylem have annular, helical and scalariform thickenings from protoxylem to metaxylem. The secondary xylem comprises tracheids, rays and axial parenchyma cells. Tracheids in the secondary xylem possess both alternate and opposite bordered pits on the radial walls. Each cross-field displays 1–2 cupressoid bordered pits. Rays are mostly uniseriate, 1–14 cells high. Leaf traces originate individually, bifurcate or not during their horizontal extension through wood, form helical clusters. Two types of arthropod coprolites were recognized in a boring in the pith. The relatively smaller coprolites containing unidentifiable plant tissues are identical with those of oribatid mites, whereas the larger coprolites exhibiting undigested plant cells probably produced by ancient millipedes. In addition to the occurrences of evident fungal hyphae, white-rot pattern and tyloses in the delignificated wood. The current study demonstrates complex ecological relationships and trophic networks occurred during the Lopingian (late Permian).

Background: Premenstrual syndrome (PMS) is a menstrual cycle-related disorder involved in brain functional dysregulation. Acupuncture is an effective alternative therapy for treating PMS, and sanyinjiao (SP6) is one of the most common acupoints used for improving the symptoms of PMS. However, it is not clear whether or not the potential mechanisms of acupuncture on PMS is related to acupuncture effects on modulating the brain of PMS. The aim of this work was to investigate the specific brain response patterns in PMS patients induced by acupuncture at SP6. Methods and Materials: 23 females with PMS were enrolled in this study. All patients received a 6-min electro-acupuncture stimulation (EAS) at SP6 and underwent two 6-min resting state fMRI scans before and after EAS. Regional homogeneity (ReHo) method was used to examine response patterns of the whole brain induced by EAS at SP6 with comparison to the resting state of pre-EAS. This study was registered at http://www.chictr.org.cn, the Clinical Trial Registration Number was ChiCTR-OPC-15005918, and the registration number was achieved at 29/01/2015. Results: Compared to pre-EAS, EAS at SP6 elicited the decreased ReHo values in the bilateral precuneus, left middle frontal cortex and right inferior frontal cortex, while increased ReHo values in the bilateral insula, bilateral thalamus, left putamen and right primary somatosensory cortex. Conclusions: The current study provide imaging evidence to support that SP6-related acupuncture stimulation could modulate the abnormal neural activity in PMS patients. Our study may partly interpret the neural mechanisms of acupuncture at SP6 which is used to treat PMS patients in clinical.

On account of complex, dangerous and limited area are urgently explored, an underwater machine which can substitute for people to complete the underwater detection is needed imminently. Autonomous underwater vehicles (AUVs) have been developed to accomplish the tasks of resource exploration in the sea. However, much higher requirements of mobility and maneuverability are of great concern with the accelerated development of AUV. Recently, vectorial thrusters have been applied to ships and offshore platforms, which can increase propulsion efficiency and flexibility. In this paper, a novel small scale AUV with vectorial thrusters is designed, the hydrodynamic performance, pressure distribution, resistance under different angles of attack (AOAs) in vertical plane motion are calculated by Computer Fluid Dynamics (CFD). The numerical simulation suggests the best underwater gesture of the new-type AUV, beyond that the content of this article will provide a basic reference for the further research of motion control.

This paper studies on a new disk-shaped AUV namely “Autonomous Underwater Helicopter” proposed at the Ocean College of Zhejiang University. The reliability of the numerical method is verified by comparison with the experimental data, in which the additional mass of the ellipsoid similar to that of the autonomous underwater helicopter is calculated. Based on the overlapping grid technology of fluid simulation software STAR-CCM+, the hydrodynamic performances of autonomous underwater helicopter in heaving motion and swaying motion are calculated under different inlet velocities and different frequencies, which provides an important references for the subsequent research and design of submarines.

Background: Amphibian skin plays an essential role in protecting organisms from harmful external factors such as UV radiation. How amphibians protect themselves from reactive oxygen species following long-term sun exposure is an important and interesting question. Amphibian skins possess a novel antioxidant system composed of various Antioxidant Peptides (AOPs), which maintain redox homeostasis. However, only a few AOPs have been identified so far. Methods: Using combinational methods of peptidomics and genomics, we characterized a novel gene-encoded antioxidant peptide (herein named OA-VI12) from Odorrana andersonii skin secretions, which was produced by the post-translational processing of a 59-residue prepropeptide. The amino acid sequence of the OA-V112 was 'VIPFLACRPLGL', with a molecular mass of 1298.6 Da and no observed post-transcriptional modifications. Functional analysis demonstrated that OA-VI12 was capable of scavenging ABTS+, DPPH, NO and decreasing the Fe3+ production. Results: We determined that the C7 amino acid was responsible for ABTS+ and Fe3+ scavenging, activities, the F4, C7, and P9 amino acids were crucial for DPPH scavenging activity, and the P9 amino acid was responsible for NO scavenging activity. Unlike several other amphibian peptides, OA-VI12 did not accelerate wound healing in a full-thickness skin-wound mouse model and did not demonstrate direct microbial killing. Here, we identified and named a novel gene-encoded antioxidant peptide from the skin secretions of an odorous frog species, which may assist in the development of potential antioxidant candidates. Conclusion: This study may help improve our understanding of the molecular basis of amphibians’ adaptation to environments experiencing long-term UV radiation.

An organic-inorganic hybrid poly(ionic liquids) material was prepared by using allyl triethoxysilane and 1-vinyl-3-octyl imidazolium bromide ionic liquids via combining free radical polymerization with sol-gel process. The prepared hybrid poly(ionic liquids) material was characterized by infrared spectroscopy and scanning electron microscopy. The adsorption properties of the prepared material to common dyes such as tartrazine, sunset yellow, amaranth and allura red were investigated. The results showed that the prepared poly(ionic liquids) material had excellent adsorption properties to sunset yellow and allura red. The adsorption capacities were 29.20 and 86.17 mg/g, respectively. When the adsorption time was 5 min, the material showed a fast adsorption rate to allura red and sunset yellow, which were 87.5% and 72.8% of the balance adsorption capacities, respectively.

Amphibian skin is known to secrete gene-encoded antioxidant peptides of small molecular weight, which play important roles in host defense. However, recognition of such peptides is still in its infancy. Here, we discovered a novel gene-encoded antioxidant peptide (named OM-GF17) from skin secretions of amphibian species, Odorrana margaretae. Produced by the post-translational processing of a 61-residue prepropeptide, the amino acid sequence of OM-GF17 was 'GFFKWHPRCGEEHSMWT', with a molecular mass of 2135.7 Da. Functional analysis revealed that OM-GF17 scavenged ABTS+, DPPH, NO and decreased iron oxidation. Our results also implied that five amino acid residues, including Cys, Pro, Met, Trp, and Phe, be related to the antioxidant activity of OM-GF17. Furthermore, OM-GF17 did not exhibit direct microbe-killing activity. This novel gene-encoded antioxidant peptide could help in the development of new antioxidant agents and increase our understanding of the biological functions of amphibian skin.

To observe the difference of clinical effects of acupoints selected based on meridian differen-tiation and conventional method for cervical spondylosis radiculopathy(CSR) treated with acupuncture and moxibustion.Sixty patients with CSR were randomly divided into an observation group and a control group,30 cases in each one.The effective rate of the observation group was 93.3%(28/30),which was better than 66.7%(20/30) of the control group(The effect of acupuncture and moxibustion based on meridian differentiation is obvious,and superior to that of conventional acupoints selection.

Polybrominated diphenyl ethers (PBDEs) are known as ubiquitous pollutants in ecological systems and thus pose a great threat to the health of humans and other organisms due to their bioamplification and bioaccumulation along the food chain. The present study was designed to investigate the biosorption capacity of biochar for the removal of 4-monobromodiphengl ether and its synergistic effect when used as a carrier to immobilize the 4-monobromodiphengl ether-degrading strain Sphingomonas sp. DZ3. The raw biochar material was prepared by pyrolyzing maize straw at 350 °C under oxygen-limited conditions. The maximum biosorption capacity of biochar for 4-bromodiphengl ether was determined to be 50.23 mg/L under an initial concentration of 800 mg/L at pH 7.0 and 40 °C. The data obtained from the biosorption studies were fitted successfully with the pseudo-first-order kinetic and Freundlich isotherm models. The Weber-Morris model analysis indicated that intraparticle diffusion was the limiting step in the biosorption of 4-bromodiphengl ether onto the biosorbent. The values of thermodynamic parameters △G0 were calculated as -24.61 kJ/mol (20 °C), -24.35 kJ/mol (30 °C), and -23.98 kJ/mol (40 °C), △S(0) was -8.45 kJ/mol/K, and △H(0) was 21.36 kJ/mol. The artificial neural network analysis indicated that the initial concentration appeared to be the most influential parameter on the biosorption processes. The removal rate of 4-bromodiphengl ether achieved using the biochar-microorganism system was increased by 63 and 83% compared with the rates obtained with biochar and the strain individually, respectively. The morphology of the biochar and immobilized strain was determined using a scanning electron microscope, and information of the surface functional groups of biochar was obtained through an infrared spectra study.

To improve the efficiency of direct solution methods in SPICE-accurate integrated circuit (IC) simulations, preconditioned iterative solution techniques have been widely studied in the past decades. However, it is still an extremely challenging task to develop robust yet efficient general-purpose preconditioning methods that can deal with various types of large-scale IC problems. In this paper, based on recent graph sparsification research we propose circuit-oriented general-purpose support-circuit preconditioning (GPSCP) methods to dramatically improve the sparse matrix solution time and reduce the memory cost during SPICE-accurate IC simulations. By sparsifying the Laplacian matrix extracted from the original circuit network using graph sparsification techniques, general-purpose support circuits can be efficiently leveraged as preconditioners for solving large Jacobian matrices through Krylov-subspace iterations. Additionally, a performance model-guided graph sparsification framework is proposed to help automatically build nearly-optimal GPSCP solvers. Our experiment results for a variety of large-scale IC designs show that the proposed preconditioning techniques can achieve up to $18 {\times }$ runtime speedups and $7 {\times }$ memory reduction in DC and transient simulations when compared to state-of-the-art direct solution methods.

A permineralised gymnosperm wood, Xenoxylon yunnanensis Feng sp. nov., is described from the Middle Jurassic Shaximiao Formation in Huize County, Yunnan Province, Southwest China. The pycnoxylic wood consists of thick-walled tracheids and thin-walled rays. It is characterised by uniseriate, contiguous, compressed bordered pits on the radial walls of tracheids, and one large simple pit in each cross-field. Growth rings exhibit narrow latewood. The mean sensitivity of analysis of 25 growth rings is 0.2, suggesting that a climate with abundant rainfall and weak seasonality could have prevailed in Yunnan, at least locally, during the Middle Jurassic. The outer portion of the wood is largely decayed, and shows poorly preserved cells lacking details. Decayed tracheids displaying various features, including removal of middle lamellae, separations of secondary walls, presence of thickened corners and appositions, are recognised as cell reactions to fungal activity. Irregularly distributed micro-cavities are formed by complete decomposition of tracheids and rays in the wood. Abundant fungal remains occurring in the wood generally consist of multiple branched hyphae. These fungal hyphae are either confined to individual cell lumens or extend through adjacent cells. Although the probable reproductive structure and typical clamp connection are very rarely observed with few septate hyphae, the affinities of these fungal hyphae are somewhat obscure. Nevertheless, our study sheds light on the palaeoecology of Middle Jurassic terrestrial ecosystems of Southwest China.

Government guarantees are frequently used to attract private investors’ participation into Build-Operate-Transfer (BOT) road projects. In this paper, we investigate the impact of government guarantees on toll charge, road quality and road capacity by taking perspective of the private investor. The main results are: (1) Minimum traffic guarantee increases toll charge while decreasing road quality. Under a low guarantee level, minimum traffic guarantee has no impact on road capacity. However, it improves road capacity when a high guarantee level is performed. (2) Under minimum revenue guarantee, if the guarantee level is sufficiently high, the optimal toll charge will be sufficiently large, but road quality and road capacity will approach zero. (3) Price compensation guarantee decreases toll charge and increases both road quality and road capacity. This paper further investigates the impact of government guarantees when the contract is auctioned. We find that auction reduces the impact of government guarantees on toll charge while failing to affect the impact of government guarantees on road quality and capacity. Some policy implications are also derived from our model results.

Oxidative stress plays an important role in the neuronal damage induced by epilepsy. The present study assessed the possible neuroprotective effects of astaxanthin (ATX) on neuronal damage, in hippocampal CA3 neurons following amygdala kindling. Male Sprague-Dawley rats were chronically kindled in the amygdala and ATX or equal volume of vehicle was given by intraperitoneally. Twenty-four hours after the last stimulation, the rats were sacrificed by decapitation. Histopathological changes and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and reduced glutathione (GSH) were measured, cytosolic cytochrome c (CytC) and caspase-3 activities in the hippocampus were also recorded. We found extensive neuronal damage in the CA3 region in the kindling group, which was preceded by increases of ROS level and MDA concentration and was followed by caspase-3 activation and an increase in cytosolic CytC. Treatment with ATX markedly attenuated the neuronal damage. In addition, ATX significantly decreased ROS and MDA concentrations and increased GSH levels. Moreover, ATX suppressed the translation of CytC release and caspase-3 activation in hippocampus. Together, these results suggest that ATX protects against neuronal loss due to epilepsy in the rat hippocampus by attenuating oxidative damage, lipid peroxidation and inhibiting the mitochondrion-related apoptotic pathway.

Public–private partnership (PPP) has been applied more and more widely for the past two decades. Questions still remain as to how to cultivate a facilitating institutional environment for developing PPP projects success. This paper examines such a question, focusing on the institutional analysis of the Chinese context. A theoretical framework of PPP governance is first developed, identifying the logics and interactions of the differentiating levels in the PPP system. Then, the institutional framework of China is presented with regard to its cultural, legal, and administrative characteristics, as the embeddedness of PPP development. Thereafter, the evolution of Chinese institutions with particular regard to PPP is analyzed. Findings show that changes in the institutional arrangements have to go in tandem with introduction of PPP, and performance of PPP is closely related with its institutional environment. Suggestions are put forward to enhance China’s institutional arrangements for healthy PPP promotion, and the implications for governments and investors in other countries are described.

In the past decades, harmonic balance (HB) has been widely used for computing steady-state solutions of nonlinear radio-frequency (RF) and microwave circuits. However, using HB for simulating strongly nonlinear post-layout RF circuits still remains a very challenging task. Although direct solution methods can be adopted to handle moderate to strong nonlinearities in HB analysis, such methods do not scale efficiently with large-scale problems due to excessively long simulation time and prohibitively large memory consumption. In this paper, we present a novel graph sparsification approach for automatically generating preconditioners that can be efficiently applied for simulating strongly nonlinear post-layout RF circuits. Our approach allows to sparsify time-domain circuit modified nodal analysis matrices that can be subsequently leveraged for sparsifying the entire HB Jacobian matrix. We show that the resultant sparsified Jacobian matrix can be used as a robust yet efficient preconditioner in HB analysis. Our experimental results show that when compared with the prior state-of-the-art direct solution method, the proposed solver can more efficiently handle moderate to strong nonlinearities during the HB analysis of RF circuits, achieving up to $20{\boldsymbol \times }$ speedups and $6{\boldsymbol \times }$ memory reductions.

The interaction of 1-dodecyl carbamoyl methylene pyridinium chloride (DAPC) with bovine serum albumin (BSA) was investigated by UV–Vis absorption, CD and fluorescence spectroscopies. The results of fluorescence titration reveal that DAPC strongly quenched the intrinsic fluorescence of BSA and caused a blue shift of the emission wavelength through a static quenching mechanism. The reduction of the binding constant (K A) and number of binding sites (n) between DAPC and BSA was studied with increasing temperature. The binding process is exothermic and entropy driven. The distance r between the donor of BSA and the acceptor of DAPC decreases with increasing concentration of DAPC. Furthermore, CD spectra and synchronous fluorescence spectra shows that DAPC induced conformational changes of BSA.

Oribatid mites (Acari: Oribatida) are very diverse and important detritivorous and fungivorous micro-arthropods in modern forest ecosystems. Although the fossil record of oribatid mites can be traced to the Early Devonian, the paleoecology of oribatid mites during the deep geological past remains poorly understood. Remarkably good preservation of tunnel networks in a permineralized conifer wood specimen is described from the Early Permian of Germany. This fossil provides evidence for four aspects of oribatid mite feeding habits. First, there is preferred consumption of the more indurated tissues from growth-ring cycles. Second, tracheids were targeted for consumption. Third, feeding on tissues resulted in fecal pellet accumulations at the bottoms of tunnels. And fourth, the absence of feeding on ambient decomposing fungi such as necroses and rots, but rather the processing of pristine plant tissues, indicate the presence of a self-contained, microorganismic gut biota. These rather specialized feeding habits allowed oribatid mites a prominent role in the decomposition of digestively refractory plant tissues in Early Permian ecosystems.

In recent years, spectral graph sparsification techniques that can compute ultra-sparse graph proxies have been extensively studied for accelerating various numerical and graph-related applications. Prior nearly-linear-time spectral sparsification methods first extract low-stretch spanning tree from the original graph to form the backbone of the sparsifier, and then recover small portions of spectrally-critical off-tree edges to the spanning tree to significantly improve the approximation quality. However, it is not clear how many off-tree edges should be recovered for achieving a desired spectral similarity level within the sparsifier. Motivated by recent graph signal processing techniques, this paper proposes a similarity-aware spectral graph sparsification framework that leverages efficient spectral off-tree edge embedding and filtering schemes to construct spectral sparsifiers with guaranteed spectral similarity (relative condition number) level. An iterative graph densification scheme is introduced to facilitate efficient and effective filtering of off-tree edges for highly ill-conditioned problems. The proposed method has been validated using various kinds of graphs obtained from public domain sparse matrix collections relevant to VLSI CAD, finite element analysis, as well as social and data networks frequently studied in many machine learning and data mining applications.

Background: Premenstrual syndrome (PMS) is a menstrual cycle-related disorder which causes physical and mood changes prior to menstruation and is associated with the functional dysregulation of the brain. Acupuncture is an effective alternative therapy for treating PMS, and sanyinjiao (SP6) is one of the most common acupoints used for improving the symptoms of PMS. However, the mechanism behind acupuncture’s efficacy for relieving PMS symptoms remains unclear. The aim of this study was to identify the brain response patterns induced by acupuncture at acupoint SP6 in patients with PMS. Materials and Methods: Twenty-three females with PMS were enrolled in this study. All patients underwent resting-state fMRI data collection before and after 6 min of electroacupuncture stimulation (EAS) at SP6. A regional homogeneity (ReHo) approach was used to compare patients’ brain responses before and after EAS at SP6 using REST software. The present study was registered at http://www.chictr.org.cn, and the Clinical Trial Registration Number is ChiCTR-OPC-15005918. Results: EAS at SP6 elicited decreased ReHo value at the bilateral precuneus, right inferior frontal cortex (IFC) and left middle frontal cortex (MFC). In contrast, increased ReHo value was found at the bilateral thalamus, bilateral insula, left putamen and right primary somatosensory cortex (S1). Conclusions: Our study provides an underlying neuroimaging evidence that the aberrant neural activity of PMS patients could be regulated by acupuncture at SP6.

Land plants are one of the major constituents of terrestrial ecosystems on Earth, and play an irreplaceable role in human activities today. If we are to understand the extant plants, it is imperative that we have some understanding of the fossil plants from the deep geological past, particularly those that occurred during their early evolutionary history, in the late Palaeozoic.

Today, cycads are a small group of gymnospermous plants with a limited distribution in the (sub)tropics, but they were major constituents of Mesozoic floras. Fossil leaves sporadically found in latest Carboniferous and Permian floras have putatively been ascribed to cycads. However, their true affinity remains unclear due to the lack of anatomical evidence. Virtually all modern cycads have pinnate leaves, but this type of leaf morphology is by no means unique for cycads. Pinnate leaves of Plagiozamites oblongifolius Halle 1927 with well-preserved cuticles showing the epidermal anatomy are here described from the upper Permian Xuanwei Formation of Yunnan Province, Southwest China. The cuticles show a clear differentiation into costal and intercostal zones; stomata are confined to the intercostal zones on both the upper and lower leaf surfaces. The external morphology and the epidermal anatomy of these fossil leaves are closely comparable with those of extant cycads, particularly members of the family Zamiaceae.

Visible-light driven reduction of CO

This paper analyzed the hydrodynamic performance of POD electric propulsor under the circumstance of different advance ratios. ANSYS-CFX solver was adopted to solve Narvier-Stokes equations with the standard SST turbulence model. The gridded 3-D model of Wageningen B4-70 propeller was implemented in this study as a thrust unit on the based both of push-POD and pull-POD propulsor. The accuracy of the numerical results of B4-70 hydrodynamic performance, including propeller thrust coefficient, torque coefficient and propeller efficiency, were verified by comparing with experimental results of open water test. Numerical analyses of hydrodynamic performance of pull-push POD propulsor were implemented respectively in one propeller revolution. The simulation results were rewarding references for designing electric propulsion system.

A new bipinnate fertile pinna, Sterzelitheca chemnitzensis, bearing alternate synangia, is described from the Chemnitz Petrified Forest, Germany. The specimen occurs in the basal volcanic ash of the Zeisigwald Tuff Horizon, Leukersdorf Formation, Lower Permian. Because it is partially embedded in the tuffaceous matrix, X-ray micro-computer tomography was employed to investigate the complete morphology without mechanical preparation of the hand specimen. The pinna is 66 mm long and branched once at least, the ultimate pinnae alternately positioned on the penultimate axis at angles of 45–55°. Stalked synangia are bell-like, borne alternately on both the terminal portion of the penultimate axis and the ultimate axes at angles of 25–60°. The smooth walled stalk is 3–7 mm long, 1–1.5 mm wide. Individual synangia are up to 6.5 mm in diameter and 10 mm long, and bear 12–14 elongated sporangia. Tubular sporangia are thin walled, circular in transverse section, arranged at the rim of the circular synangial pad around a central hollow. The unique preservational mould of the studied specimen is neither a permineralisation nor a compression–impression. It is three-dimensionally preserved, but lacks any organic remains. We provide the first detailed three-dimensional features of a probable medullosan male reproductive organ from the Chemnitz Fossil Lagerstatte. The relatively simple structure of the specimen offers a better understanding of the Palaeozoic seed ferns.

Realizable power grid reduction becomes a key to efficient design and verification of nowadays large-scale power delivery networks. Existing state-of-the-art realizable reduction techniques for interconnect circuits, such as the TICER algorithm, cannot be well suited for effective power grid reductions, since reducing the mesh-structured power grids by TICER's nodal elimination scheme may introduce excessive number of new edges in the reduced grids that can be even harder to solve than the original grid due to the drastically increased sparse matrix density. In this paper, we present a novel geometric template-based reduction technique for reducing large-scale flip-chip power grids. Our method first creates geometric template according to the original power grid topology and then performs novel iterative grid corrections to improve the accuracy by matching the electrical behaviors of the reduced template grid with the original grid. In addition, a multilevel grid correction scheme has been proposed to achieve faster convergence during the grid reduction process, which allows for effectively handling very large-scale power grids with millions of parasitics components and thousands of ports. Our experimental results show that the proposed reduction method can reduce industrial power grid designs by up to 95% with a very satisfactory solution quality obtained in dc and transient analysis.

In this paper, we formulate and analyse a long-term multi-objective dynamic model for controlling invasive species. This optimization framework is then applied to the case of buffelgrass control in the Arizona desert. The proposed model simultaneously optimizes three objectives corresponding to three different valued and threatened resources including saguaros (a native cactus species), buildings and vegetation. The model is used to decide the optimal allocation of labour to these resources to control the population of the species in a multi-period planning horizon. The computational method to solve this problem is based on multi-objective integer programming.

Traditional biological treatment for triphenylmethane dye effluent is stuck with the inaccessibility of dye molecules to intracellular dye-degrading enzyme, thus a high-efficiency and low-cost method for dye decolorization is highly desirable. Here we established a bioremediation approach to display triphenylmethane reductase (TMR) on the surface of Escherichia coli (E. coli) using N-terminal of ice nucleation protein as anchoring motif for triphenylmethane dye decolorization for the first time. Approximately 85% of recombinant protein positioning on the surface of E. coil cells exhibited high activity and stability. The optimal temperature and pH of the surface-displayed TMR are 50 °C and 8.5, respectively. Comparing with other reported microorganisms, the decolorization rate for malachite green of this engineered strain is the highest so far, reaching 640 μmol min(-1) g(-1) dry weight cells. These results indicate that this engineered E. coli strain is a very promising candidate for synthetic dye removal.

Leaf skeletonization represents a distinctive form of insect feeding behavior. It commonly occurs in angiosperm leaves after their initial appearance during the Early Cretaceous. This type of feeding behavior rarely has been documented in pre-Mesozoic fossils. We describe the earliest evidence of insect-skeletonized leaves of Dictyophyllum nathorstii Zeiller, affi li- ated with the extant fern family Dipteridaceae in the Late Triassic Yipinglang fl ora from southwestern China. The skeletonization generally is located adjacent to the pinna rachilla of the distal free portion of the leaf. In the skeletonized area, the interveinal tissue is com- pletely removed, exposing the pinna rachilla, pinnule midveins, and lateral veins. Most non- vascular tissue has been removed between the vascular bundles, the latter forming polygo- nal meshes of varying size. Our report of insect-mediated skeletonization of fern leaves from southwestern China fi lls a spatiotemporal gap in the published data on the paleogeographi- cal distribution and stratigraphic occurrence of plant-arthropod associations, and indicates an antagonistic relationship between a fern host and its insect herbivore.

Noeggerathiales are an extinct group of spore-bearing plants of uncertain systematic position that are known from Carboniferous and Permian age Euramerican and Cathaysian floras that occurred in present-day Europe, North America, and East Asia. The order Noeggerathiales includes over 50 species of more than 20 fossil genera, but their paleoecology is not well understood yet. Previously this group had been found only in extrabasinal floras or those inhabiting clastic wetlands. Noeggerathiales have never been recorded in coal ball floras. Thus, it is up to now uncertain whether this group has contributed to the formation of coal. Recent investigations of an Early Permian peat-forming flora of the Taiyuan Formation near Wuda, Inner Mongolia, which was preserved in a volcanic ash fall has provided evidence that noeggerathialean plants not only existed in the peat-forming vegetation but could even be the dominant group in some areas of the coal swamp. The Noeggerathiales in this particular peat-forming forest include Tingia unita, Paratingia wudensis, and a new species of Paratingia. Exceptionally well-preserved specimens indicate that these noeggerathialean plants are small trees with a canopy of compound leaves and strobili near the top of an unbranched (monocaulous) stem.

Buffelgrass (Pennisetum ciliare) is a fire-prone, African bunchgrass spreading rapidly across the southern Arizona desert. This article introduces a model that simulates buffelgrass spread over a gridded landscape over time to evaluate strategies to control this invasive species. Weed-carrying capacity, treatment costs, and damages vary across grid cells. Damage from buffelgrass depends on its density and proximity to valued resources. Damages include negative effects on native species (through spatial competition) and increased fire risk to land and buildings. We evaluate recommended “rule of thumb” control strategies in terms of their ability to prevent weed establishment in newly infested areas and to reduce damage indices over time. Two such strategies—potential damage weighting and consecutive year treatment—used in combination, provided significant improvements in long-term control over no control and over a strategy of minimizing current damages in each year. Results suggest specific recommendations for deploying rapid-response teams to prevent establishment in new areas. The long-run population size and spatial distribution of buffelgrass is sensitive to the priority given to protecting different resources. Land managers with different priorities may pursue quite different control strategies, posing a challenge for coordinating control across jurisdictions.

Production sharing contracts (PSCs) and buyback contracts are two important contract modes in the upstream oil industry. In this paper, we build a theoretical model to compare investment and production levels under these two contracts. Our model results show that PSCs lead to higher investment levels than buyback contracts. Moreover, investment level increases with international oil companies’ (IOCs') share under buyback contracts. The comparison of optimal oil production depends on IOCs' share under PSCs and the host government's marginal operating costs from oil production under buyback contracts. When IOCs' share of gross revenues or the host government's marginal operating costs are low, optimal oil production is higher under buyback contracts; otherwise, optimal oil production is higher under PSCs. Based on such a comparison, we investigate the host government's best decisions on revenue division under these two contract types. We demonstrate that optimal share ratios exist for the host government to obtain maximum oil revenues under both contract types. We also find that under both contracts the discount factor and oil price positively affect optimal investment and production levels, respectively. Our results can provide policy implications for the host government when selecting upstream oil contracts in international oil cooperation.

Spontaneous carotid cavernous fistula is usually caused by lesions in the internal carotid cavernous sinus and its branches. We report a young male patient with no history of trauma, in whom the fistula was located at the cavernous sinus of the internal carotid artery. The postoperative angiography found a pseudoaneurysm at the origin of the cavernous sinus of internal carotid artery, which suggested that cavernous sinus fistulas were caused by bleeding from rupture of thin-walled vessels due to the local abnormalities of the vascular wall.