Theoretical and experimental biology in one<br>—A symposium in honour of Professor Kuo-Chen Chou’s 50th anniversary and Professor Richard Giegé’s 40th anniversary of their scientific careers

It has been a dream that theoretical biology can be extensively applied in experimental biology to accelerate the understanding of the sophiscated movements in living organisms. A brave assay and an excellent example were represented by enzymology, in which the well-established physico-chemistry is used to describe, to fit, to predict and to improve enzyme reactions. Before the modern bioinformatics, the developments of the combination of theoretical biology and experimental biology have been mainly limited to various classic formulations. The systematic use of graphic rules by Prof. Kuo-Chen Chou and his co-workers has significantly facilitated to deal with complicated enzyme systems. With the recent fast progress of bioinformatics, prediction of protein structures and various protein attributes have been well established by Chou and co-workers, stimulating the experimental biology. For example, their recent method for predicting protein subcellular localization (one of the important attributes of proteins) has been extensively applied by scientific colleagues, yielding many new results with thousands of citations. The research by Prof. Chou is characterized by introducing novel physical concepts as well as powerful and elegant mathematical methods into important biomedical problems, a focus throughout his career, even when facing enormous difficulties. His efforts in 50 years have greatly helped us to realize the dream to make “theoretical and experimental biology in one”. Prof. Richard Giege is well known for his multi-disciplinary research combining physics, chemistry, enzymology and molecular biology. His major focus of study is on the identity of tRNAs and their interactions with aminoacyl-tRNA synthetases (aaRS), which are of critical importance to the fidelity of protein biosynthesis. He and his colleagues have carried out the first crystallization of a tRNA/aaRS complex, that between tRNAAsp and AspRS from yeast. The determination of the complex structure contributed significantly to under- stand the interaction of protein and RNA. From his fine research, they have also found other biological function of these small RNAs. He has developed in parallel appropriate methods for his research, of which the protein crystallogenesis, a name he has coined, is an excellent example. Now macromolecular crystallogenesis has become a developed science. In fact, such contribution has accelerated the development of protein crystallography, stimulating the study of macromolecular structure and function.

Experimental models of high-risk bowel anastomosis in rats:A systematic review

BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.

Experimental Investigation of Laser Surface Hardening of AISI 4340 Steel Using Different Laser Scanning Patterns

Laser surface transformation hardening becomes one of the most modern processes used to improve fatigue and wear properties of steel surfaces. In this process, the material properties and the heating parameters are the factors that present the most significant effects on the hardened surface attributes. The control of these factors using predictive modeling approaches to achieve desired surface properties leads to conclusive results. However, when the dimensions of the surface to be treated are larger than the cross-section of the laser beam, various laser-scanning patterns are involved. This paper presents an experimental investigation of laser surface hardening of AISI 4340 steel using different laser scanning patterns. This investigation is based on a structured experimental design using the Taguchi method and improved statistical analysis tools. Experiments are carried out using a 3 kW Nd: YAG laser source in order to evaluate the effects of the heating parameters and patterns design parameters on the physical and geometrical characteristics of the hardened surface. Laser power, scanning speed and scanning patterns (linear, sinusoidal, triangular and trochoid) are the factors used to evaluate the hardened depth and the hardened width variations and to identify the possible relationship between these factors and the hardened zone attributes. Various statistical tools such as ANOVA, correlations analysis and response surfaces are applied in order to examine the effects of the experimental factors on the hardened surface characteristics. The results reveal that the scanning patterns do not modify the nature of the laser parameters’ effects on the hardened depth and the hardened width. But they can accentuate or reduce these effects depending on the type of the considered pattern. The results show also that the sinusoidal and the triangular patterns are relevant when a maximum hardened width with an acceptable hardened depth is desired.

Fasudil-modified macrophages reduce inflammation and regulate the immune response in experimental autoimmune encephalomyelitis

Multiple sclerosis is characterized by demyelination and neuronal loss caused by inflammatory cell activation and infiltration into the central nervous system.Macrophage polarization plays an important role in the pathogenesis of experimental autoimmune encephalomyelitis,a traditional experimental model of multiple sclerosis.This study investigated the effect of Fasudil on macrophages and examined the therapeutic potential of Fasudil-modified macrophages in experimental autoimmune encephalomyelitis.We found that Fasudil induced the conversion of macrophages from the pro-inflammatory M1 type to the anti-inflammatory M2 type,as shown by reduced expression of inducible nitric oxide synthase/nitric oxide,interleukin-12,and CD16/32 and increased expression of arginase-1,interleukin-10,CD14,and CD206,which was linked to inhibition of Rho kinase activity,decreased expression of toll-like receptors,nuclear factor-κB,and components of the mitogen-activated protein kinase signaling pathway,and generation of the pro-inflammatory cytokines tumor necrosis factor-α,interleukin-1β,and interleukin-6.Crucially,Fasudil-modified macrophages effectively decreased the impact of experimental autoimmune encephalomyelitis,resulting in later onset of disease,lower symptom scores,less weight loss,and reduced demyelination compared with unmodified macrophages.In addition,Fasudil-modified macrophages decreased interleukin-17 expression on CD4^(+)T cells and CD16/32,inducible nitric oxide synthase,and interleukin-12 expression on F4/80^(+)macrophages,as well as increasing interleukin-10 expression on CD4^(+)T cells and arginase-1,CD206,and interleukin-10 expression on F4/80^(+)macrophages,which improved immune regulation and reduced inflammation.These findings suggest that Fasudil-modified macrophages may help treat experimental autoimmune encephalomyelitis by inducing M2 macrophage polarization and inhibiting the inflammatory response,thereby providing new insight into cell immunotherapy for multiple sclerosis.

Incidence and histopathology of encysted progenetic metacercaria of Clinostomum complanatum(Digenea:Clinostomidae) in Channa punctatus and its development in experimental host

Objective:To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum(C. complanatum) in Channa punctatus(C. punctatus), associated histopathology and the experimental infection to laboratory chicken to obtain ovigerous adult worms.Methods:Live C. punctatus were brought from local fish market of Aligarh, India, dissected and examined on a monthly basis for the presence of C. complanatumcysts. For histochemistry, infected tissue sections with attached cysts were processed for haematoxylene and eosin staining. Cysts were aseptically fed to 4 day old leghorn chicken to obtain adult worms. Mechanically excysted metacercaria and the ovigerous adult worms were stained in carmine to prepare permanent slides.Results:One year survey for the infection of encysted progenetic metacercaria of C.complanatuminC. punctatusrevealed the prevalence, intensity and abundance of 24.7%, 2.27and 0.608, respectively. Histopathology showed heavy infiltration of immune cells at the site of cyst attachment and some tissue damage was also evident. Following feeding to experimental chicken, about 41.07% of the encysted metacercariae were able to excyst and migrate back to bucco-pharyngeal region where they tenaciously attached and fed on blood, and transformed into ovigerous adult worms from 62 hours onwards of post infection.Conclusions:The parasite is potentially pathogenic to the host, and the availability of a suitable intermediate host can be a contributing factor for the occurrence of C. complanatummetacercaria either in the excysted or encysted form, indicating loose host specificity and zoonotic potential.

Experimental study on antitumor effect of arsenic trioxide in combination with cisplatin or doxorubicin on hepatocellular carcinoma

INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo studies[1-5]. Due to limited effectiveness when any anti-carcinogen is used alone and obviously increased toxicity when the dose is raised, there is no exception for As2O3. Furthermore, combined chemotherapy contributes to improve therapeutic effectiveness, disperse toxicity and surmount drug-resistance,in which the combination of traditional Chinese and modern medicine has more advantages and characteristics. As a result,we made an experimental study on anti-tumor effect of As2O3in combination with cisplantin (PDD) or doxorubicin (ADM)on HCC. to investigate the possibility of AS2O3 in combination with PDD or ADM and nature of interaction between them,and to provide experimental basis for clinical application.

Regulating effect of Chinese herbal medicine on the peritoneal lymphatic stomata in enhancing ascites absorption of experimental hepatofibrotic mice

AIM: To observe the regulatory effect of Chinese herbal medicine on peritoneal lymphatic stomata and its significance in treating ascites in liver fibrosis model mice. METHODS: Two Chinese herbal composite prescriptions were used separately to treat the carbon tetrachloride-induced mouse model of liver fibrosis. The histo-pathologic changes of the liver sections (HE and VG stainings) were observed. The peritoneal lymphatic stomata was detected by scanning electron microscopy and computer image processing. The changes of urinary volume and sodium ion concentration were measured. RESULTS: In the model group, lots of fibrous tissue formed in liver and extended into the hepatic lobules to separate them incompletely. In the treated and prevention groups, the histo-pathologic changes of liver was rather milder, only showed much less fibrous tissue proliferation in the hepatic lobules. The peritoneal lymphatic stomata enlarged with increased density in the experimental groups (diameter: PA, 3.07 +/- 0.69 microm; PB, 2.82 +/- 0.37 microm; TA, 3.25 +/- 0.82 microm and TB, 2.82 +/- 0.56 microm; density: PA, 7.11 +/- 1.90 stomata.1000 microm(-2); PB, 8.76 +/- 1.45 stomata.1000 microm(-2); TA, 6.55 +/- 1.44 stomata.1000 microm(-2)and TB, 8.76+/-1.79 stomata.1000 microm(-2)), as compared with the model group (diameter: 2.00+/-0.52 microm density: 4.45+/-1.05 stomata.1000 microm(-2)). After treatment, the urinary volume and sodium ion excretion increased in the experimental groups (PA, 231.28+/-41.09 mmol.L(-1); PB, 171.69 +/- 27.48 mmol.L(-1) and TA, 231.44 +/- 34.12 mmol.L(-1)), which were significantly different with those in the model group (129.33 +/- 36.75 mmol.L(-1)). CONCLUSION: Chinese herbal medicine has marked effects in alleviating liver fibrosis, regulating peritoneal lymphatic stomata, improving the drainage of ascites from peritoneal cavity and causing increase of urinary volume and sodium ion excretion to reduce the water and sodium retention, and thus have favorable therapeutic effect in treating ascites.

Weld Models Incorporating the HAZ Phase Transformation Effects, Comparison between Experimental and Numerical Results

Numerical simulations of a representative test of welding process are presented in this paper. A French vessel steel, which involves metallurgical phase transformations in solid state is considered in this work. The aim is to validate the thermal-metallurgical-mechanical models taking into account the metallurgical transformations in the finite element codes Sysweld (Framasoft) and Code Aster (EDF). The test is performed on a thin disc submitted to a thermal cycle loading by means of a CO2 laser beam, which leads to metallurgical phase transformations. The thermal, metallurgical and mechanical numerical results have been compared to the experimental results (temperatures, sizes of transformed zones, displacements and residual stresses and strains). The main objective of the numerical analysis is to have some results which enable to give some indications on the ability of the numerical codes to describe the observed phenomena. For that, it is necessary to simulate accurately the thermo-metallurgical history. The comparison of experimental results with the numerical ones leads to some interesting orientations related to the capacities of the considered models to describe the observed phenomena.

CO hydrogenation combined with water-gas-shift reaction for synthetic natural gas production:a thermodynamic and experimental study

The hydrogenation of CO to synthetic natural gas (SNG) needs a high molar ratio of H2/CO (usually large than 3.0 in industry), which consumes a large abundant of hydrogen. The reverse dry reforming reaction (RDR, 2H2 + 2CO←→CH4 + CO2), combining CO methanation with water-gas-shift reaction, can significantly decrease the H2/CO molar ratio to 1 for SNG production. A detailed thermodynamic analysis of RDR reaction was carried out based on the Gibbs free energy minimization method. The effect of temperature, pressure. H2/CO ratio and the addition of H2O, CH4, CO2, O2 and C2H4 into the feed gas on CO conversion, CH4 and CO2 selectivity, as well as CH4 and carbon yield, are discussed. Experimental results obtained on homemade impregnated Ni/Al2O3 catalyst are compared with the calculations. The results demonstrate that low temperature (200-500 °C), high pressure (1-5 MPa) and high H2/CO ratio (at least 1) promote CO conversion and CH4 selectivity and decrease carbon yield. Steam and CO2 in the feed gas decrease the CH4 selectivity and carb on yield, and enhance the CO2 con tent. Extra CH4 elevates the CH4 content in the products, but leads to more carbon formation at high temperatures. O2 significantly decreases the CH4 selectivity and C2H4 results in the generation of carbon.

An experimental proposal for low order laboratory animals’ extension of metabolic life

Essential bibliography, with therein references included, is presented owing to the contribution of the author groups to Mitochondrial Filamentation, which is a new emerging field of physiological energy metabolism. These studies provide the first seed concept for trials to extend the metabolic life, for a few days, in low order laboratory mammals killed by electrocution, as a first type of accidental death. It is proposed, essentially, to cool out the corpses very soon after death at 12oC-14oC and take advantage of the effect super magnetism to counteract the force of gravity to install a net recurrent cycle of oxygen consumption and oxygen production by filamented mitochondria in all the organism tissues. Once the cause of death had been corrected adequately, it is possible to try the reanimation to experience the full life of the corpse with highly sophisticated methodology.

Analysis of the Erosion-Corrosion Mechanism of the Air Cooler in a Hydrocracking Unit:A Numerical and Experimental Study

Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirmed that the damage was caused by erosion-corrosion(E-C).Numerical and experimental methods were applied to investigate the E-C mechanism in the air cooler.Computational fluid dynamics(CFD)was used to calculate the hydrodynamic parameters of the air cooler.The results showed that there was a biased flow in the air cooler,which led to a significant increase in velocity,turbulent kinetic energy and wall shear within 0.2 m of the tube entrance.A visualization experiment was then performed to determine the principles of migration and transformation of multiphase flow in the air cooler tubes.Various flow patterns(pure droplet flow,mist flow,and annular flow)and their evolutionary processes were clearly depicted experimentally.The initiation mechanism and processes leading to the development of E-C in the air cooler were also determined.This study provided a comprehensive explanation for the E-C failures that occur in air coolers during operation.

Consideration on the Flow Velocity in the Experimental Analysis of the Flame Displacement Speed Using DNS Data of Turbulent Premixed Flames with Different Lewis Numbers

The flame displacement speed is one of the major characteristics in turbulent premixed flames. The flame displacement speed is experimentally obtained from the displacement normal to the flame surface, while it is numerically evaluated by the transport equation of the flame surface. The flame displacement speeds obtained both experimentally and numerically cannot be compared directly because their definitions are different. In this study, two kinds of experimental flame displacement speeds—involving the mean inflow velocity and the local flow velocity—were simulated using the DNS data with the different Lewis numbers, and were compared with the numerical flame displacement speed. The simulated experimental flame displacement speed involving the mean inflow velocity had no correlation with the numerical flame displacement speed, while the simulated displacement speed involving the local flow velocity had a clear correlation with the numerical displacement speed in the cases of higher Lewis number than unity. The correlation coefficient of the simulated displacement speed involving the local flow velocity with the numerical displacement speed had a maximum value on the isosurface of the reaction progress variable with the maximum temperature gradient where the dilation effect of the flame is strongest.

Basic Experimental Pancreatitis Models for Beginners

Efforts to find an ideal model for pancreatitis date back to 1960’s. Many models are suggested since then. Every model has its own advantages and disadvantages. Some of these models test etiology while others simulate the complications of pancreatitis. An ideal model which by itself demonstrates all aspects of pancreatitis including systemic changes is yet to be described. In this review we tried to gather the basic, easy to construct models.

Experimental Analysis of Radial Centrifugal Pump Shutdown

Centrifugal pumps are widely used in the metallurgy,coal,and building sectors.In order to study the hydraulic characteristics of a closed impeller centrifugal pump during its shutdown in the so-called power frequency and frequency conversion modes,experiments were carried to determine the characteristic evolution of parameters such as speed,inlet and outlet pressure,head,flow rate and shaft power.A quasi-steady-state method was also used to further investigate these transient behaviors.The results show that,compared to the power frequency input,the performance parameter curves for the frequency conversion input are less volatile and smoother.The characteristic time is longer and the response to shutdown is slower.The quasi-steady-state theoretical head-flow curves match the experimental head-flow curves more closely at low flow rates when the frequency conversion input is considered.Moreover,in this case,the similarity law predicts the hydraulic performance more accurately.

Emodin attenuates inflammation and demyelination in experimental autoimmune encephalomyelitis

Emodin,a substance extracted from herbs such as rhubarb,has a protective effect on the central nervous system.However,the potential therapeutic effect of emodin in the context of multiple sclerosis remains unknown.In this study,a rat model of experimental autoimmune encephalomyelitis was established by immune induction to simulate multiple sclerosis,and the rats were intraperitoneally injected with emodin(20 mg/kg/d)from the day of immune induction until they were sacrificed.In this model,the nucleotide-binding domain-like receptor family pyrin domain containing 3(NLRP3)inflammasome and the microglia exacerbated neuroinflammation,playing an important role in the development of multiple sclerosis.In addition,silent information regulator of transcription 1(SIRT1)/peroxisome proliferator-activated receptor-alpha coactivator(PGC-1α)was found to inhibit activation of the NLRP3 inflammasome,and SIRT1 activation reduced disease severity in experimental autoimmune encephalomyelitis.Furthermore,treatment with emodin decreased body weight loss and neurobehavioral deficits,alleviated inflammatory cell infiltration and demyelination,reduced the expression of inflammatory cytokines,inhibited microglial aggregation and activation,decreased the levels of NLRP3 signaling pathway molecules,and increased the expression of SIRT1 and PGC-1α.These findings suggest that emodin improves the symptoms of experimental autoimmune encephalomyelitis,possibly through regulating the SIRT1/PGC-1α/NLRP3 signaling pathway and inhibiting microglial inflammation.These findings provide experimental evidence for treatment of multiple sclerosis with emodin,enlarging the scope of clinical application for emodin.

Comparative transcriptomic analysis reveals the molecular changes of acute pancreatitis in experimental models

BACKGROUND Acute pancreatitis(AP)encompasses a spectrum of pancreatic inflammatory conditions,ranging from mild inflammation to severe pancreatic necrosis and multisystem organ failure.Given the challenges associated with obtaining human pancreatic samples,research on AP predominantly relies on animal models.In this study,we aimed to elucidate the fundamental molecular mechanisms underlying AP using various AP models.AIM To investigate the shared molecular changes underlying the development of AP across varying severity levels.METHODS AP was induced in animal models through treatment with caerulein alone or in combination with lipopolysaccharide(LPS).Additionally,using Ptf1αto drive the specific expression of the hM3 promoter in pancreatic acinar cells transgenic C57BL/6J-hM3/Ptf1α(cre)mice were administered Clozapine N-oxide to induce AP.Subsequently,we conducted RNA sequencing of pancreatic tissues and validated the expression of significantly different genes using the Gene Expression Omnibus(GEO)database.RESULTS Caerulein-induced AP showed severe inflammation and edema,which were exacerbated when combined with LPS and accompanied by partial pancreatic tissue necrosis.Compared with the control group,RNA sequencing analysis revealed 880 significantly differentially expressed genes in the caerulein model and 885 in the caerulein combined with the LPS model.Kyoto Encyclopedia of Genes and Genomes enrichment analysis and Gene Set Enrichment Analysis indicated substantial enrichment of the TLR and NOD-like receptor signaling pathway,TLR signaling pathway,and NF-κB signaling pathway,alongside elevated levels of apoptosis-related pathways,such as apoptosis,P53 pathway,and phagosome pathway.The significantly elevated genes in the TLR and NOD-like receptor signaling pathways,as well as in the apoptosis pathway,were validated through quantitative real-time PCR experiments in animal models.Validation from the GEO database revealed that only MYD88 concurred in both mouse pancreatic tissue and human AP peripheral blood,while TLR1,TLR7,RIPK3,and OAS2 genes exhibited marked elevation in human AP.The genes TUBA1A and GADD45A played significant roles in apoptosis within human AP.The transgenic mouse model hM3/Ptf1α(cre)successfully validated significant differential genes in the TLR and NOD-like receptor signaling pathways as well as the apoptosis pathway,indicating that these pathways represent shared pathological processes in AP across different models.CONCLUSION The TLR and NOD receptor signaling pathways play crucial roles in the inflammatory progression of AP,notably the MYD88 gene.Apoptosis holds a central position in the necrotic processes of AP,with TUBA1A and GADD45A genes exhibiting prominence in human AP.

Auto-parametric resonance of a continuous-beam-bridge model under two-point periodic excitation:an experimental investigation and stability analysis

The auto-parametric resonance of a continuous-beam bridge model subjected to a two-point periodic excitation is experimentally and numerically investigated in this study.An auto-parametric resonance experiment of the test model is conducted to observe and measure the auto-parametric resonance of a continuous beam under a two-point excitation on columns.The parametric vibration equation is established for the test model using the finite-element method.The auto-parametric resonance stability of the structure is analyzed by using Newmark's method and the energy-growth exponent method.The effects of the phase difference of the two-point excitation on the stability boundaries of auto-parametric resonance are studied for the test model.Compared with the experiment,the numerical instability predictions of auto-parametric resonance are consistent with the test phenomena,and the numerical stability boundaries of auto-parametric resonance agree with the experimental ones.For a continuous beam bridge,when the ratio of multipoint excitation frequency(applied to the columns)to natural frequency of the continuous girder is approximately equal to 2,the continuous beam may undergo a strong auto-parametric resonance.Combined with the present experiment and analysis,a hypothesis of Volgograd Bridge's serpentine vibration is discussed.

Efficacy of Juanbi capsule on ameliorating knee osteoarthritis:a network pharmacology and experimental verification-based study

Background:The purpose of the study was to investigate the active ingredients and potential biochemical mechanisms of Juanbi capsule in knee osteoarthritis based on network pharmacology,molecular docking and animal experiments.Methods:Chemical components for each drug in the Juanbi capsule were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,while the target proteins for knee osteoarthritis were retrieved from the Drugbank,GeneCards,and OMIM databases.The study compared information on knee osteoarthritis and the targets of drugs to identify common elements.The data was imported into the STRING platform to generate a protein-protein interaction network diagram.Subsequently,a“component-target”network diagram was created using the screened drug components and target information with Cytoscape software.Common targets were imported into Metascape for GO function and KEGG pathway enrichment analysis.AutoDockTools was utilized to predict the molecular docking of the primary chemical components and core targets.Ultimately,the key targets were validated through animal experiments.Results:Juanbi capsule ameliorated Knee osteoarthritis mainly by affecting tumor necrosis factor,interleukin1β,MMP9,PTGS2,VEGFA,TP53,and other cytokines through quercetin,kaempferol,andβ-sitosterol.The drug also influenced the AGE-RAGE,interleukin-17,tumor necrosis factor,Relaxin,and NF-κB signaling pathways.The network pharmacology analysis results were further validated in animal experiments.The results indicated that Juanbi capsule could decrease the levels of tumor necrosis factor-αand interleukin-1βin the serum and synovial fluid of knee osteoarthritis rats and also down-regulate the expression levels of MMP9 and PTGS2 proteins in the articular cartilage.Conclusion:Juanbi capsule may improve the knee bone microstructure and reduce the expression of inflammatory factors of knee osteoarthritis via multiple targets and multiple signaling pathways.

Are Invasive Genotypes Superior? An Experimental Approach Using Native and Invasive Genotypes of the Invasive Grass <i>Phalaris Arundinacea</i>

The admixture and recombination of individuals from the native range into a new range may lead to the production of invasive genotypes that have higher fitness and wider climatic tolerances than the native genotypes. In this paper, we compare the survival and growth of native EU and invasive NA genotypes when planted back into the native EU range near where the EU genotypes were collected. We test this hypothesis using the invasive wetland grass Phalaris arundinacea. If invasive genotypes have evolved to have higher survival and growth, then they should outperform the native EU genotypes under field conditions that are better suited to the EU genotypes. Individual plants of the wetland grass, Phalaris arundinacea collected from native Europe (Czech Republic (CZ) and France (FR)) and North America (Vermont (VT) and North Carolina (NC)) were planted into common gardens in Trebon, Czech Republic (49.0042&deg;N, 14.7721&deg;E) and Moussac, France (43.9808&deg;N, 4.2241&deg;E). Invasive genotypes from North Carolina (NC) survived as well or better than native genotypes in both the Trebon and Moussac garden. Additionally, invasive NC genotypes suffered higher herbivore damage than native genotypes but their growth and survival were not significantly different than genotypes from the other re-gions. A companion field experiment that simulated biomass removal through grazing indicated that invasive NC genotypes recovered faster following grazing than genotypes from other regions. Our results suggest that not all invasive genotypes are superior and regional differences in aggressiveness between invasive genotypes are as great as differences between individuals from native and invasive populations. Introduction of genotypes leading to invasion depends upon the environmental conditions and the suitability of the climate for the introduced individuals.

Experimental study on reactions between alkaline basaltic melt and orthopyroxenes: constraints on the evolution of lithospheric mantle in the North China Craton

The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this paper.The reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric mantle.The starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,Hebei Province.The results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–T conditions.The formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff ect.Temperature is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the melt.Temperature also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted melt.The formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this mineral.Therefore,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 contents.In addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions between the latter and orthopyroxene.