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Viruses are non-living organisms that rely on host cellular metabolism to complete their life cycle. Siniperca chuatsi rhabdovirus (SCRV) has caused huge economic losses to the Chinese perch (Siniperca chuatsi) industry worldwide. SCRV replication is dependent on the cellular glutamine metabolism, while aspartate metabolism plays an important role in viral proliferation in glutamine deficiency. Herein, we investigated roles of asparagine metabolism in SCRV proliferation. Results showed that SCRV infection upregulated the expression of key enzymes in the aspartate metabolic pathway in CPB cells. And the key enzymes of malate-aspartic acid shuttle pathway upregulated during the virus invasion phase, and key enzymes of the asparagine biosynthesis pathway upregulated during the viral replication and release phase. When asparagine was added to the depleted medium, the SCRV copy number restored to 90% of those in replete medium, showing that asparagine and glutamine completely rescue the replication of SCRV. Moreover, inhibition of the aspartate- malate shuttle pathway and knockdown of the expression of key enzymes in the asparagine biosynthesis pathway significantly reduced SCRV production, indicating that the aspartic acid metabolic pathway was required to the replication and proliferation of SCRV. Above results provided references for elucidating pathogenic mechanism of SCRV by regulation of aspartate metabolism.

Graph Neural Networks (GNNs) have been widely applied on a variety of real-world applications, such as social recommendation. However, existing GNN-based models on social recommendation suffer from serious problems of generalization and oversmoothness, because of the underexplored negative sampling method and the direct implanting of the off-the-shelf GNN models. In this paper, we propose a succinct multi-network GNN-based neural model (NeMo) for social recommendation. Compared with the existing methods, the proposed model explores a generative negative sampling strategy, and leverages both the positive and negative user-item interactions for users' interest propagation. The experiments show that NeMo outperforms the state-of-the-art baselines on various real-world benchmark datasets (e.g., by up to 38.8% in terms of NDCG@15).

Kaiying Yu,1– 3,* Lihui Liu,3,4,* Xiaowei Zhang,1– 3 Zhanzhi Zhang,1– 3 Benqiang Rao,1– 3 Yongbing Chen,1– 3 Suyun Li,2,3 Hanping Shi1– 3 1Department of General Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, People’s Republic of China; 2Department of Clinical Nutrition, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, People’s Republic of China; 3Ninth School of Clinical Medicine, Peking University, Beijing 100038, People’s Republic of China; 4Department of Nursing, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hanping ShiDepartment of General Surgery, Beijing Shijitan Hospital, Capital Medical University, No. 10th Tieyi Road, Haidian District, Beijing 100038, People’s Republic of ChinaTel +86-13802741263Fax +86-010-63926519Email shihp@vip.163.comPurpose: Malignant bowel obstruction (MBO) is a common problem in late-stage cancer patients. Many factors are suggested to be associated with the prognosis of MBO. The current investigation was designed to explore the factors associated with the prognosis of conservative and surgery treatment in one single institution.Patients and Methods: Sixty-four patients of MBO were recruited into the study. Demographic and clinical data including gender, age, primary cancer, radiological and laboratory examinations, and nutritional and pain index scaling were extracted for further analysis. Kaplan–Meier analysis and logistic regression analysis were used to compare the prognosis and detect significant factors.Results: Of the 64 patients, there is no statistical difference in baseline features between conservative and surgical group. However, the length of stay, total medical costs, re-admission interval, and re-admission rate are statistically significant. There is no significance in Kaplan–Meier log rank test for median survival time, though the overall survival time in the conservative group is longer than that of the surgery group. Logistic regression analysis has found that prior chemotherapy is a significant predictor for final survival outcome.Conclusion: The election of surgery might not improve the overall survival time. Non-surgical procedures, especially chemotherapy, might be preferable for MBO patients.Keywords: malignant bowel obstruction, surgical treatment, conservative management, prognosis, survival

The LIM domain family genes play a crucial role in various tumors, including non-small-cell lung cancer (NSCLC). Immunotherapy is one of the most significant treatments for NSCLC, and its effectiveness largely depends on the tumor microenvironment (TME). Currently, the potential roles of LIM domain family genes in the TME of NSCLC remain elusive. We comprehensively evaluated the expression and mutation patterns of 47 LIM domain family genes in 1089 NSCLC samples. Using unsupervised clustering analysis, we classified patients with NSCLC into two distinct gene clusters, i.e., the LIM-high group and the LIM-low group. We further investigated the prognosis, TME cell infiltration characteristics, and immunotherapy in the two groups. The LIM-high and LIM-low groups had different biological processes and prognoses. Moreover, there were significant differences in TME characteristics between the LIM-high and LIM-low groups. Specifically, enhanced survival, immune cell activation, and high tumor purity were demonstrated in patients of the LIM-low group, implying an immune-inflamed phenotype. Moreover, the LIM-low group had higher immune cell proportion scores than the LIM-high group and was more responsive to immunotherapy than the LIM-low group. Additionally, we screened out LIM and senescent cell antigen-like domain 1 (LIMS1) as a hub gene of the LIM domain family via five different algorithms of plug-in cytoHubba and the weighted gene co-expression network analysis. Subsequently, proliferation, migration, and invasion assays demonstrated that LIMS1 acts as a pro-tumor gene that promotes the invasion and progression of NSCLC cell lines. This is the first study to reveal a novel LIM domain family gene-related molecular pattern associated with the TME phenotype, which would increase our understanding of the heterogeneity and plasticity of the TME in NSCLC. LIMS1 may serve as a potential therapeutic target for NSCLC.

The Qilian Mountain Ecological Zone has an important location and rich biodiversity. It is the source of the main water resources in Jiuquan City. In order to improve the disaster prevention and mitigation capabilities of Jiuquan City, improve the Qilian Mountains' ecological environmental protection capabilities, provide ecological meteorological disaster monitoring, forecasting, and early warning services, use regional weather station observation data and satellite remote sensing monitoring technology to integrate high spatial resolution image data and geographic. The information system is closely integrated, and extensive ecological monitoring has been carried out in the areas of snow cover, grassland vegetation, and reservoir capacity in the middle and western sections of the Qilian Mountains. It has also played a role in monitoring and evaluating artificial weather modification in Jiuquan City.The production of Jiuquan Eco-Meteorological Monitoring Bulletin application products through data analysis and evaluation provides a scientific basis for the ecological environmental protection and restoration of Qilian Mountains, further promotes and guarantees the rapid development of local economic and social science, and strengthens the construction and service of meteorological undertakings.

Spinel ferrite compounds continue to receive a lot of attention due to their unique properties. Among the numerous synthesis routes existing, the solid-state method was applied for the production of nickel ferrite, by introducing the use of a quartz vial. A mixture of nickel oxide (NiO) and hematite (Fe2O3) was ground and vacuum-sealed in the vial and different thermal treatment programs were tested. The resulting particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. For temperatures, below 1000 °C, the solid-state reaction is not complete as nickel oxide (NiO) and hematite (Fe2O3) are still present. The reaction time is a decisive parameter for the morphology of the particles obtained. If, for different reaction times, the particle size distribution is always between 0.3 and 1.7 µm, a longer reaction time leads to the formation of dense, interconnected clusters of particles. Optimal parameters to synthesize a pure phase of spherical nickel ferrite were sought and found to be a reaction temperature of 1000 °C for 72 h.

Reasoning is a fundamental capability for harnessing valuable insight, knowledge and patterns from knowledge graphs. Existing work has primarily been focusing on point-wise reasoning, including search, link predication, entity prediction, subgraph matching and so on. This paper introduces comparative reasoning over knowledge graphs, which aims to infer the commonality and inconsistency with respect to multiple pieces of clues. We envision that the comparative reasoning will complement and expand the existing point-wise reasoning over knowledge graphs. In detail, we develop KompaRe, the first of its kind prototype system that provides comparative reasoning capability over large knowledge graphs. We present both the system architecture and its core algorithms, including knowledge segment extraction, pairwise reasoning and collective reasoning. Empirical evaluations demonstrate the efficacy of the proposed KompaRe., 9 pages, 8 figures

P is a ray parameter. Seismic wave path of P gather spreads nearly along the ray path. Compared with angle gather, P gather can be obtained directly from seismic data and is independent of overlying strata velocity, which avoids the inversion error caused by inaccurate velocity models. Based on P stacked gather, ray elastic impedance of different P values and pre-stack elastic parameters have been computed using Bayesian sparse pulse inversion and constrained search method, respectively. The method has been applied to reservoir prediction of the Yuanba area in the north of Sichuan depression. Exploration results indicated that P stacked data can better delineate the geological body compared with angle stacked data. In addition, stable solutions are easier to be obtained by Bayesian sparse pulse inversion and constrained search method. The pre-stack elastic parameters of P gather showed higher precision and more authenticity than that of angle gather. This methodology has achieved excellent results in reservoir prediction of the Yuanba area and has huge potential for future application in exploration and development.

The interaction between the high-energy particles in the plume and the spacecraft surfaces will produce interference torque that affects the operating state of the spacecraft in orbit. The thrust of an electric propulsion system is quite small, so it is difficult to be measured directly. The Vacuum Plume Laboratory (VPL) measured the LIPS-200 type ion thruster plume force in an order of 10 − 3 N using a fully elastic micro thrust measuring device. In this paper, the particle in cell (PIC) method and the direct simulation Monte Carlo (DSMC) method are employed to analyze the three-dimensional plasma environments under specified experimental conditions. The Maxwell model is used to calculate the plume force on a 300 mm diameter plate. Simulation results of the plume force give good agreements with the experimental data. Moreover, the effects of the 300 mm diameter aluminium plate on the flow field in vacuum conditions are analyzed. The results show that the number density of atoms is greatly increased before the plate, which has a further impact on the distribution of charge exchange ions (CEX). The enhanced CEX ions moving towards the solar battery panels or sensitive optical components may cause possible damage or interference, which should be avoided by the designers.

Diachasmimoorpha longicaudata (Ashmead, D. longicaudata) (Hymenoptera: Braconidae) is a solitary species of parasitoid wasp and widely used in integrated pest management (IPM) programs as a biological control agent in order to suppress tephritid fruit flies of economic importance. Although many studies have investigated the behaviors in the detection of their hosts, little is known of the molecular information of their chemosensory system. We assembled the first transcriptome of D. longgicaudata using transcriptome sequencing and identified 162,621 unigenes for the Ashmead insects in response to fruit flies fed with different fruits (guava, mango, and carambola). We annotated these transcripts on both the gene and protein levels by aligning them to databases (e.g., NR, NT, KEGG, GO, PFAM, UniProt/SwissProt) and prediction software (e.g., SignalP, RNAMMER, TMHMM Sever). CPC2 and MIREAP were used to predict the potential noncoding RNAs and microRNAs, respectively. Based on these annotations, we found 43, 69, 60, 689, 26 and 14 transcripts encoding odorant-binding protein (OBP), chemosensory proteins (CSPs), gustatory receptor (GR), odorant receptor (OR), odorant ionotropic receptor (IR), and sensory neuron membrane protein (SNMP), respectively. Sequence analysis identified the conserved six Cys in OBP sequences and phylogenetic analysis further supported the identification of OBPs and CSPs. Furthermore, 9 OBPs, 13 CSPs, 3 GRs, 4IRs, 25 ORs, and 4 SNMPs were differentially expressed in the insects in response to fruit flies with different scents. These results support that the olfactory genes of the parasitoid wasps were specifically expressed in response to their hosts with different scents. Our findings improve our understanding of the behaviors of insects in the detection of their hosts on the molecular level. More importantly, it provides a valuable resource for D. longicaudata research and will benefit the IPM programs and other researchers in this filed.

User attribute inference plays an important role in personalized recommendation and precision marketing. However, in large-scale social networks, user attributes are often missing. To address the problem, this paper introduces an inference framework for deriving missing attributes of users in largescale social networks. We use Sina Weibo as our experimental platform. The framework leverages various collaborative filtering methods and a similarity learning scheme to infer missing user attribute values. Experimental results demonstrate the proposed framework is able to generate satisfactory inference results.

Electric propulsion systems, such as ion thrusters and Hall thrusters, are widely utilized in aerospace. The target indirect measurement method (TIMM) is a simple and robust way to measure its thrust. In general, one can obtain the thrust by scaling up the force exerted on the target surface immersed in the plume flow. However, the charge exchange (CEX) allows ions to become neutral particles, increasing the scaling coefficient. Meanwhile, the sputtered atoms and reflected incident particles exert force on the target surface and enlarge the measured thrust. In this study, the effects of the CEX, the sputtering, and the reflection on the TIMM are mathematically quantified, and then a modified model of the TIMM is proposed. Besides, the thrusts of the LIPS-200 and LIPS-300 ion thrusters were separately measured using the TIMM with the modified model, and the measured thrusts are in good agreement with the rated thrusts. Under the test conditions, the results of the LIPS-300 ion thruster show that the fast neutral atoms produced by the CEX account for more than 20% of all fast particles impacting on the target, and the force caused by the sputtered atoms is about 3.4% of the total force exerted on the target. We discuss how test conditions affect the CEX, sputtering, and reflection, thereby influencing the TIMM. The modified model was also validated through the simulation results, by showing that the measured thrust cannot be influenced by the test conditions.

The back-sputtering deposition on thruster surface caused by ion bombardment on chamber wall material affects the performance of thrusters during the ground based electric propulsion endurance tests. In order to decrease the back-sputtering deposition, most of vacuum chambers applied in electric propulsion experiments are equipped with anti-sputtering targets. In this paper, a three-dimensional model of plume experimental system (PES) including double layer anti-sputtering target is established. Simulation cases are made to simulate the plasma environment and sputtering effects when an ion thruster is working. The particle in cell (PIC) method and direct simulation Monte Carlo (DSMC) method is used to calculate the velocity and position of particles. Yamamura's model is used to simulate the sputtering process. The distribution of sputtered anti-sputtering target material is presented. The results show that the double layer anti-sputtering target can significantly reduce the deposition on thruster surface. The back-sputtering deposition rates on thruster exit surface for different cases are compared. The chevrons on the secondary target are rearranged to improve its performance. The position of secondary target has relation with the ion beam divergence angle, and the radius of the vacuum chamber. The back-sputtering deposition rate is lower when the secondary target covers the entire ion beam.

When the plume of electric thrusters, which is the plasma flow, collides with a surface of spacecraft, a force is exerted on the surface, causing the spacecraft to be flipped or deorbited. The force is generated by the plasma–surface interactions, which can be described using the momentum accommodation coefficient (MAC). As far as we know, only the MAC where the plasma flow is assumed as the combination of singly charged ions, electrons, and neutral gases has been studied. However, the plasma flow of electric thrusters contains not only singly charged ions but also multiply charged ions. In addition, the plasma–surface interactions are usually accompanied by the charged-exchange (CEX), sputtering, and plasma sheath, all of which influence the momentum transfer. Therefore, in this study, the MAC in plasma–surface interactions is developed by quantifying the effect of the multiply charged ions, CEX, sputtering, and plasma sheath. The formulas of the normal momentum accommodation coefficient (NMAC) and tangential momentum accommodation coefficient are derived, respectively, and then, a measurement method of the MAC is proposed with the derived formulas. Moreover, a NMAC was measured when the plasma flow, which was jetted by an ion thruster with an acceleration voltage of 1000 V, impacted an immersed surface vertically, and the measured NMAC is approximated as 1.0. The effect degree and mechanism of the aforementioned factors on the MAC were discussed. Finally, the force exerted on the immersed surface was simulated using the measured NMAC, and the results are in good agreement with the experimental results.

A thermostatic E × B probe is designed to protect the probe body from the thermal effect of the plasma plume that has a significant influence on the resolution of the probe for high-power electric thrusters. An active cooling system, which consists of a cooling panel and carbon fiber felts combined with a recycling system of liquid coolants or an open-type system of gas coolants, is employed to realize the protection of the probe. The threshold for the design parameters for the active cooling system is estimated by deriving the energy transfer of the plasma plume-probe body interaction and the energy taken away by the coolants, and the design details are explained. The diagnostics of the LIPS-300 ion thruster with a power of 3 kW and a screen-grid voltage of 1450 V was implemented by the designed thermostatic E × B probe. The measured spectra illustrate that the thermostatic E × B probe can distinguish the fractions of Xe+ ions and Xe2+ ions without areas of overlap. In addition, the temperature of the probe body was less than 306 K in the beam region of the plasma plume during the 200-min-long continuous test. A thermostatic E × B probe is useful for enhancing the viability and versatility of equipment and for reducing uneconomical and complex test procedures.

The aim of this investigation was to assess the in-vitro interaction of two antifungal agents, econazole-nitrate and chelerythrine, against ten fluconazole-resistant clinical isolates and one ATCC type strain 10231 of Candida albicans. The checkerboard microdilution method was performed according to the recommendations of the National Committee for Clinical Laboratory Standards, and the results were determined by visual examination. The interaction intensity was tested in all isolates using the fractional inhibitory concentration index (FICI). These experiments showed synergism between econazole-nitrate and chelerythrine in antifungal activity against C. albicans, and no antagonistic activity was observed in any of the strains tested. Moreover, time-kill curves were performed with selected strains to confirm the positive interactions. The similarity between the results of the FICI values and the time-kill curves revealed that chelerythrine greatly enhances the antifungal effects of econazole-nitrate against isolates of C. albicans. This synergistic effect may markedly reduce the dose of econazole-nitrate required to treat candidiasis, thereby decreasing the econazole-nitrate toxic side effects. This novel synergism might provide a potential combination treatment against fungal infections.

A momentum flux measuring instrument (MFMI), which ranges from 1 mN∼300 N, is designed to measure the parameters related to the momentum flux of exhaust plume of attitude and orbit control thrusters covered electric and chemical thrusters. A MFMI with the variable-range provides an efficient and economy way to study the exhaust plume of both electric and chemical thrusters. The flexural pivots, replaceable strain gauge, replaceable target plate, and force arm with the variable length make it possible. The designed MFMI with the non-displacement measurement can reduce the influence of pipelines and test lines, especially the elastic force and friction due to displacement. The designed MFMI system with the range of 0∼100 mN and 0∼15 N was calibrated separately. The target indirect measurement method is a simple and economical option for measuring the thrust of electric thrusters, and is employed to measure the thrust of the LIPS-200 ion thruster using the designed MFMI. Research indicates that the sputtering contributes to the momentum transfer of plasma-surface interactions. In addition, the high-speed charged ions from the thruster will experience a charge-exchange (CEX) collision with the slow neutral background. Therefore, the influence of the sputtering and CEX on target indirect measurement method is derived in detail, and then the measured thrust is corrected. The measured average thrust, which is 40.1 mN, demonstrates that the designed MFMI is effective. The designed MFMI can also be employed as a thrust stand by directly mounting the thrusters on torsional arm, and a maximum of three thrusters can be installed on the MFMI at the same time.

We study cosmology induced by an ideal superstring gas at finite temperature. The thermal/quantum effects of the string gas generate a nontrivial effective potential at one-loop level. At certain points in the moduli space where generically massive states become massless, the effective potential develops local minima. The latter serve as moduli attractors, which induce time-dependent scalar masses decreasing in cosmological time. As a result, the coherent scalar oscillations dilute before nucleosynthesis, and the cosmological moduli problem is avoided. In particular, we study moduli stabilization in the cases of cosmology induced by i) a maximally supersymmetric heterotic string gas; ii) a gas of type II string compactified on Calabi-Yau three-folds. In case i), the local minima of the potential arise at enhanced gauge symmetry points, which can stabilize all moduli but the dilaton. In case ii), local minima of the effective potential are reached at the loci where 2-spheres or 3-spheres in the Calabi-Yau space shrink to zero size, giving rise to either conifold transitions or non Abelian gauge symmetries. Extra massless states are induced by D-brane wrapping the shrinking spheres, and the stabilized moduli are those controlling the volume of those spheres. In addition, in the two cases we also study respectively the type I dual theory which is maximally supersymmetric and the heterotic dual theory compactified on K3xT2. We show that dual moduli can be stabilized by novel non-perturbative effects implied by duality maps., On étudie la cosmologie induite par un gaz parfait de supercordes à température finie. Les effets thermaux et quantiques du gaz de cordes génèrent un potentiel effectif au niveau d'une boucle. A certains points dans l'espace de modules où les masses des états génériquement massifs s'annulent, le potentiel effectif atteint des minima locaux. Les modules qui y sont attirés prennent des masses qui diminuent avec le temps, ce qui permet aux oscillations cohérentes des modules d'être diluées avant la nucléosynthèse. Ainsi le modèle ne rencontre pas le problème des modules cosmologiques. En particulier, on étudie la stabilisation des modules pour la cosmologie induite par i) un gaz de cordes hétérotiques maximalement supersymétriques, ii) un gaz de cordes de type II compactifiées sur un espace de Calabi-Yau de dimension complexe 3. Dans le 1er cas, les minima locaux du potentiel effectif apparaissent aux points de symétries de jauge étendues. Ceux-ci stabilisent tous les modules sauf le dilaton. Dans le 2ème cas, les minima locaux du potentiel effectif sont atteints où des 2- ou 3-sphères dans l'espace de Calabi-Yau s'évanouissent, produisant une transition conifold ou une extension du groupe non Abelien de jauge. Les états non massifs supplémentaires sont engendrés par des D-branes s'enroulant sur les sphères qui s'évanouissent et les modules stabilisés sont ceux qui contrôlent les volumes de ces sphères. Pour les deux cas, on étudie aussi respectivement les théories duales de type I maximalement supersymétrique et hétérotique compactifiée sur K3xT2. On trouve que les modules duaux sont stabilisés par des effets non perturbatifs impliqués par les dualités concernées.

Recent results of Hartle-Hawking wave functions on asymptotic dS boundaries show non-normalizability, while the bulk origin is not clear. This paper attempts to addresse this problem by studying (Kerr-)dS_3 cosmology in Einstein gravity deformed by a minimally coupled scalar field. Various saddle-point contributions exp[i(saddle-point action)] to the Hartle-Hawking wave functions are computed with mini-superspace formalism. The saddle-point actions are first obtained in the spacetime bulks by direct computation, then on the asymptotic dS boundary by holographic renormalization. It is found that the imaginary part of the saddle-point actions, as functions of scalar field deformation, are generally bounded in the bulk, but can diverge to -infty on the boundary. This can probably be a source of the scalar field-related non-normalizability of the boundary Hartle-Hawking wave functions. For Kerr-dS_3 cosmology, some saddle-point actions have imaginary parts diverging to -infty both in the bulk and on the boundary, when the boundary T^2 is stretched to infinitely long. This can be an origin of non-normalizability of the boundary Hartle-Hawking wave functions related to temperature divergence. Finally the holographic renormalization is extended to scalar-deformed dS_{d+1} (d>= 3) cosmologies for the imaginary part of the saddle-point actions. The result is tested on a 5d example, and saddle points leading to divergent contribution to the boundary Hartle-Hawking wave function are shown to exist., 68 pages 32 figures; In v2: typos eliminated; a misjudge of mass range in 3d corrected, related contents revised in Sec.2.3, Sec.7 and appendix B; the 4d example in Sec.6.2 is replaced by a 5d one, due to possible author right clash with another paper in preparation; references added or updated

In these lecture notes I give a pedagogical introduction to the thermodynamics of ideal string gases. The computation of thermodynamic quantities in the canonical ensemble formalism will be shown in detail with explicit examples. Attention will be given mainly to the thermodynamical consequences of string degrees of freedom, where I will especially address i) the Hagedorn temperature, a critical temperature above which the canonical ensemble description breaks down, which can be the onset point of some instability of the string gas; ii) the phase structure arising from compactification, embodied in the moduli-dependence of the Helmholtz free energy, which corrects the tree-level vacuum and can provide mechanism for moduli stabilization. Then I will briefly explain the implementation of string gas thermodynamics in cosmology, showing a simple example which gives rise to a radiation-dominated early universe. Further phenomenological issues and open questions will be discussed qualitatively with references indicated, including the Hagedorn instability in the resolution of the initial singularity, moduli stabilization, generation of hierarchy, radiative symmetry breaking and primordial cosmological fluctuations.

We study the Hamiltonian formulation of the generally covariant theory defined by the Lagrangian 4-form L=e_I e_J F^{IJ}(\omega) where e^I is a tetrad field and F^{IJ} is the curvature of a Lorentz connection \omega^{IJ}. This theory can be thought of as the limit of the Holst action for gravity for the Newton constant G goes to infinity and Immirzi parameter goes to zero, while keeping their product fixed. This theory has for a long time been conjectured to be topological. We prove this statement both in the covariant phase space formulation as well as in the standard Dirac formulation. In the time gauge, the unconstrained phase space of theory admits an SU(2) connection formulation which makes it isomorphic to the unconstrained phase space of gravity in terms of Ashtekar-Barbero variables. Among possible physical applications, we argue that the quantization of this topological theory might shed new light on the nature of the degrees of freedom that are responsible for black entropy in loop quantum gravity., Comment: Appendix added where moldels leading to boundary degrees of freedom are constructed. This version will appear in PRD.

Vibrio parahaemolyticus(VP)is a pathogen of bacterial food poisoning associated with shellfish.VP,which is detected both in human and fish,has even higher concentrations in oysters and other filter-feeding shellfish.In order to study the relationship of VP densities versus water quality factor including water salinity,temperature,pH and dissolved oxygen in the course of oyster culture,we detected total VP densities in the oyster and water quality factor at the oyster farm in Yangxi,Guangdong from March to November in 2009.The results showed that the detection ratio of total VP in oysters was 94.38%.The water temperature was correlated positively with total VP in oysters,but the salinity was correlated negatively with total VP in oysters.The dissolved oxygen and pH didn't show correlation with total VP in oysters.Based on the regression analysis,a quadratic relationship for VP densities versus water temperature and salinity was found.The regression equation of VP densities versus water temperature was:LgVP=0.093T-0.685(R2=0.336);The regression equation of VP densities versus salinity was:LgVP=1.199+0.116S-0.004S2(R2=0.217);The best fit regression equation of VP densities versus water temperature and salinity was LgVP=-1.941+0.116T+0.058S-0.001S2(R2=0.414).The results of this paper may provide some reference data for the risk analysis of VP during oyster culture.

In these lecture notes I give a pedagogical introduction to the thermodynamics of ideal string gases. The computation of thermodynamic quantities in the canonical ensemble formalism will be shown in detail with explicit examples. Attention will be given mainly to the thermodynamical consequences of string degrees of freedom, where I will especially address i) the Hagedorn temperature, a critical temperature above which the canonical ensemble description breaks down, which can be the onset point of some instability of the string gas; ii) the phase structure arising from compactification, embodied in the moduli-dependence of the Helmholtz free energy, which corrects the tree-level vacuum and can provide mechanism for moduli stabilization. Then I will briefly explain the implementation of string gas thermodynamics in cosmology, showing a simple example which gives rise to a radiation-dominated early universe. Further phenomenological issues and open questions will be discussed qualitatively with references indicated, including the Hagedorn instability in the resolution of the initial singularity, moduli stabilization, generation of hierarchy, radiative symmetry breaking and primordial cosmological fluctuations., 54 pages, 1 figure, based on lectures given at the Eighth Modave Summer School in Mathematical Physics on 29th and 30th August 2012, Modave, Belgium Published in PoS in 2013: http://pos.sissa.it/archive/conferences/195/002/Modave%20VIII_002.pdf Minor difference from the published version. The work in progress indicated by Ref[58] is published: R.Brandenberger et al, [arXiv:1312.2524]