A total of 335 lactating sows (Landrace x Large White) were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) for mixed parity ...A total of 335 lactating sows (Landrace x Large White) were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) for mixed parity sows during lactation. In Exp. 1, 185 sows (weighing an average of 256.2 ± 6.5 kg and having an average parity of 3.4 ± 0.3) were allocated to one of six experimental diets in a completely randomized block design within parity groups (1, 2, and 3+). The experimental diets were formulated to contain 3.06, 3.16, 3.20, 3.25, 3.30 or 3.40 Mcal/kg of ME and each diet was fed to the sows throughout a 28 day lactation. All diets provided a similar SID-lysine level (0.86%). As a result, the diets provided a SID-Lys:ME ratio of 2.81, 2.72, 2.69, 2.65, 2.61 or 2.53 g/Mcal ME. Sow feed intake was significantly (P 〈 0.01) affected by the energy content of the diet as well as by sow parity. Using regression analysis, feed intake was shown to be maximized at 3.25, 3.21, 3.21 and 3.21 Mcal/kg of ME for parity 1, 2, 3+ sows and the entire cohort of sows respectively (quadratic; P 〈 0.01). In addition, the result of feed intake can be expressed as 2.65, 2.69, 2.69 and 2.68 g/Mcal based on analysis of SID-Lys:ME ratio. Litter weight gain was affected by dietary treatment for parity 3+ sows and the entire cohort (P 〈 0.01). Based on regression analysis, litter weight gain was maximized at 3.25 and 3.24 Mcal/kg of ME for parity 3+ (quadratic; P 〈 0.01) and the entire cohort (quadratic; P 〈 0.01). Similarly, the result of litter weight gain could be expressed as 2.65 and 2.66 g/Mcal of SID- Lys:ME ratio. Therefore, 3.25 Mcal/kg of ME was selected for Exp. 2 in which 150 sows (weighing 254.6 ± 7.3 kg and having an average parity of 3.4 ± 0.4) were allocated to one of five treatments in a completely randomized block design within parity (1, 2, and 3+). The experimental diets were formulated to contain 2.1, 2.4, 2.7, 3.0 or 3.3 g/Mcal of SID-Lys:ME ratio with all diets providing 3.25 Mcal/kg of ME. The diets were fed to the sows throughout a 28 day lactation. Sow body weight loss was affected by dietary treatment (parity 3+ sows, P = 0.02; entire cohort, P 〈 0.01) and by sow parity (P 〈 0.01). Litter weight at weaning and litter weight gain were affected by dietary treatment for parity 1, 2, 3+ sows and the entire cohort (P 〈 0.01) as well as by sow parity (P 〈 0.01). Plasma urea nitrogen (P 〈 0.01), creatinine (P 〈 0.01) and non-esterifide fatty acids (P = 0.04) were decreased as the SID-Lys:ME ratio of the diet increased. Insulin-like growth factor-1 (P = 0.02), estradiol (P 〈 0.01) and luteinizing hormone (P = 0.02) were increased as the SID-Lys:ME ratio in diet increased. Based on a broken-line model, the estimated SID-Lys: ME ratio to maximize litter weight gain was estimated to be 3.05 g/Mcal.展开更多
In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a n...In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed performance are demonstrated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating representation.Finally, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.展开更多
Huanglongbing (HLB, or citrus greening) is the most destructive disease of citrus, which is associated with Candidatus Liberibacter asiaticus (Las). Few management options are available, aside from preventive meas...Huanglongbing (HLB, or citrus greening) is the most destructive disease of citrus, which is associated with Candidatus Liberibacter asiaticus (Las). Few management options are available, aside from preventive measures such as removing infected plants, planting disease-free seedlings, and managing the insect vector. In this study, we assessed the efficacy of thermotherapy against HLB under controlled greenhouse conditions. A total of 60 two-year-old, graft-infected Citrus reticulata Blanco plants were used. The plants were randomly divided into three groups (45℃, 48℃, and untreated control), with five plants/replicate (rep) and four reps/treatment. The treated plants were placed in phytotrons for a 4-h treatment session, repeated once per week for three consecutive weeks. Disease remission was observed eight weeks post-treatment. Real-time PCR assays revealed that Las titers in HLB-affected seedlings were significantly reduced in both 45 and 48℃ treatments four weeks after treatment, with the exception of eight plants. In contrast, Las titers in the untreated control plants increased significantly during the same period, with a maximum increase of 28-fold. Except for seven plants, Las titers in the new flushes of treated plants decreased more than 90% eight weeks after treatment. Las titers in mature leaves of treated plants decreased 56 and 60% in average at 45 and 48℃, respectively, eight weeks after treatment. The HLB symptoms and Las titer of seedings were markedly alleviated eight weeks after treatment in both 45 and 48℃ treatments. Our results laid a good foundation for the further development of citrus free-disease seedling cultivation and Huanglongbing control in the field. The whole plants were replaced for scion or branch in previous as the research object in this study, and the expression of Huanglongbing symptoms combined with real-time polymerase chain reaction (PCR) were used to evaluate the effect of heat treatment in the greenhouse.展开更多
AIM: To investigate the effects of lubiprostone and Polyethylene Glycol 3350 (PEG) on mucosal barrier repair in ischernic-injured porcine intestine. METHODS: Ileum from 6 piglets (approximately 15 kg body weight...AIM: To investigate the effects of lubiprostone and Polyethylene Glycol 3350 (PEG) on mucosal barrier repair in ischernic-injured porcine intestine. METHODS: Ileum from 6 piglets (approximately 15 kg body weight) was subjected to ischemic conditions by occluding the local rnesenteric circulation for 45 min in vivo. Ileal tissues from each pig were then harvested and mounted in Ussing chambers and bathed in oxygenated Ringer's solution in vitro. Intestinal barrier function was assessed by measuring transepithelial electrical resistance (TER) and mucosal-to-serosal fluxes of ^3H-rnannitol and ^14C-inulin. Statistical analyses of data collected over a 120-min time course included 2-way ANOVA for the effects of time and treatment on indices of barrier function. RESULTS: Application of 1μmol/L lubiprostone to the rnucosal surface of ischemic-injured ileum in vitro induced significant elevations in TER compared to nontreated tissue. Lubiprostone also reduced mucosal-toserosal fluxes of ^3H-rnannitol and ^14C-inulin. Alternatively, application of a polyethylene laxative (PEG, 20 rnmol/L) to the mucosal surface of ischernic tissues significantly increased flux of ^3H-rnannitol and ^14C-inulin. CONCLUSION: This experiment demonstrates that lubiprostone stimulates recovery of barrier function in ischemic intestinal tissues whereas the PEG laxative had deleterious effects on mucosal repair. These results suggest that, unlike osmotic laxatives, lubiprostone stimulates repair of the injured intestinal barrier.展开更多
By means of varied statistical methods, such as normalized root mean square error (RMSE), correlation analysis, empirical orthogonal function (EOF) decomposition, etc., the reliability of the varied seasonal anoma...By means of varied statistical methods, such as normalized root mean square error (RMSE), correlation analysis, empirical orthogonal function (EOF) decomposition, etc., the reliability of the varied seasonal anomalies of NCEP/NCAR reanalyzed wind speed and surface air temperature (SAT) data frequently used in the climate change research in China is studied. Results show that RMSEs of meteorological variables are smaller in eastern China than in western China, i.e., the reliability of NCEP/NCAR reanalysis in eastern China is better than that in western China. This could be due to effects of the topography in the reanalysis model and the disposition of "dense-in-eastern-and-sparse-in-western" of meteorological stations in China. The RMSE of anomalies of reanalyzed wind speeds decreases with increasing height, further confirming the possible impact of topography on reliability of reanalysis. Results of correlation analysis inversely correspond to those of RMSE analysis, i.e., if the RMSE is larger, the correlation between reanalyzed and observed data is worse, and vice versa. It is found from comparing the EOF eigenvectors of anomaly of reanalyzed and observed data that if a meteorological variable has smaller RMSE, the spatial patterns of corresponding EOF eigenvectors of anomaly of reanalyzed and observed data are similar and their time coefficients are significantly correlated, and vice versa. Therefore, the similarity of EOF modes and" the consistency of their time coefficients can be used to objectively assess the reliability of the reanalysis. On the whole, the reliability of the reanalyzed wind speed is better in spring, summer, and autumn, but worse in winter; and for the reanalyzed SAT, it is the best in winter and the worst in summer.展开更多
Recent years have witnessed a processor develop- ment trend that integrates central processing unit (CPU) and graphic processing unit (GPU) into a single chip. The inte- gration helps to save some host-device data...Recent years have witnessed a processor develop- ment trend that integrates central processing unit (CPU) and graphic processing unit (GPU) into a single chip. The inte- gration helps to save some host-device data copying that a discrete GPU usually requires, but also introduces deep re- source sharing and possible interference between CPU and GPU. This work investigates the performance implications of independently co-running CPU and GPU programs on these platforms. First, we perform a comprehensive measurement that covers a wide variety of factors, including processor ar- chitectures, operating systems, benchmarks, timing mecha- nisms, inputs, and power management schemes. These mea- surements reveal a number of surprising observations. We an- alyze these observations and produce a list of novel insights, including the important roles of operating system (OS) con- text switching and power management in determining the program performance, and the subtle effect of CPU-GPU data copying. Finally, we confirm those insights through case studies, and point out some promising directions to mitigate anomalous performance degradation on integrated heteroge- neous processors.展开更多
Plant roots and their associated mycorrhizal fungi critically mediate the decomposition of soil organic carbon(C),but the general patterns of their impacts over a broad geographical range and the primary mediating fac...Plant roots and their associated mycorrhizal fungi critically mediate the decomposition of soil organic carbon(C),but the general patterns of their impacts over a broad geographical range and the primary mediating factors remain unclear.Based on a synthesis of 596 paired observations from both field and greenhouse experiments,we found that living roots and/or mycorrhizal fungi increased organic C decomposition by 30.9%,but low soil nitrogen(N)availability(i.e.,high soil C:N ratio)critically mitigated this promotion effect.In addition,the positive effects of living roots and/or mycorrhizal fungi on organic C decomposition were higher under herbaceous and leguminous plants than under woody and non-leguminous plants,respectively.Surprisingly,there was no significant difference between arbuscular mycorrhizal fungi and ectomycorrhizal fungi in their effects on organic C decomposition.Furthermore,roots and/or mycorrhizal fungi significantly enhanced the decomposition of leaf litter but not root litter.These findings advance our understanding of how roots and their symbiotic fungi modulate soil C dynamics in the rhizosphere or mycorrhizosphere and may help improve predictions of soil global C balance under a changing climate.展开更多
Efficient generation of spin polarization is very important for spintronics and quantum computation. In chiral materials without magnetic order nor spin-orbit coupling, we find a new spin selectivity effect—chiral ph...Efficient generation of spin polarization is very important for spintronics and quantum computation. In chiral materials without magnetic order nor spin-orbit coupling, we find a new spin selectivity effect—chiral phonon activated spin Seebeck(CPASS)effect. Starting with the nonequilibrium distribution of chiral phonons under a temperature gradient, the CPASS coefficients are computed based on the Boltzmann transport theory. With both the phonon-drag and band transport contributions, the spin accumulations generated by the CPASS effect exhibit quadratic dependence on the temperature gradient. The strength of the CPASS effect and the relative magnitude of both contributions are tunable by the chemical potential modulation. The CPASS effect, which gives a promising explanation on the traditional chiral-induced spin selectivity effect, provides opportunities for the exploration of advanced spintronic devices based on chiral materials even in the absence of any magnetic order and spin-orbit coupling.展开更多
Bacterial cellulose(BC)is an exopolysaccharide with unique properties that has been applied in various fields.However,the dense and intertwined nature of BC fibers limits its use in certain applications,including 3D p...Bacterial cellulose(BC)is an exopolysaccharide with unique properties that has been applied in various fields.However,the dense and intertwined nature of BC fibers limits its use in certain applications,including 3D printing scaffolds for bone regeneration.In this work,a controllable BC-based bio-ink for 3D printing was successfully prepared by modifying the neat BC through maleic acid(MA)treatment,aiming to promote bone tissue regeneration.To achieve homogeneous BC dispersions while preserving its crystalline and chemical properties,BC was modified by MA solution(60%,w/V)with solid-liquid ratio from 1꞉5 to 1꞉50(w/V)to obtain MA-BC dispersions.The analysis results from microstructure,chemical group,crystallinity,and wettability indicated that the BC/MA solution with ratio of 1꞉30 demonstrated the best pre-treatment performance to obtain MA-BC.Subsequently,by combining MA-BC with gelatin,we successfully formulated MA-BC-GEL gels with favorable rheological properties and compression modulus,which can be used as promising bio-inks for 3D bioprinting applications.In vitro tests demonstrated 1꞉30 MA-BC possessed excellent biocompatibility,a significant ability to express the alkaline phosphatase gene and osteogenic-related genes,and facilitated the formation of mineralized nodules.The utilization of this novel bio-ink in scaffold preparation for bone regeneration highlights the promising application of modified BC in bone tissue engineering field.展开更多
In this paper, a new computation method and an optimization algorithm are presented for feedrate scheduling of five-axis machining in compliance with both machine drive limits and process limits. Five-axis machine too...In this paper, a new computation method and an optimization algorithm are presented for feedrate scheduling of five-axis machining in compliance with both machine drive limits and process limits. Five-axis machine tool with its ability of controlling tool orientation to follow the sculptured surface contour has been widely used in modern manufacturing industry. Feedrate scheduling serving as a kernel of CNC control system plays a critical role to ensure the required machining accuracy and reliability for five-axis machining. Due to the nonlinear coupling effects of all involved drive axes and the saturation limit of servo motors, the feedrate scheduling for multi-axis machining has long been recognized and remains as a critical challenge for achieving five-axis machine tools’ full capacity and advantage. To solve the nonlinearity nature of the five-axis feedrate scheduling problems, a relaxation mathematical process is presented for relaxing both the drive motors’ physical limitations and the kinematic constraints of five-axis tool motions. Based on the primary optimization variable of feedrate, the presented method analytically linearizes the machining-related constraints, in terms of the machines’ axis velocities, axis accelerations and axis jerks. The nonlinear multi-constrained feedrate scheduling problem is transformed into a manageable linear programming problem. An optimization algorithm is presented to find the optimal feedrate scheduling solution for the five-axis machining problems. Both computer implementation and laboratorial experiment testing by actual machine cutting were conducted and presented in this paper. The experiment results demonstrate that the proposed method can effectively generate efficient feedrate scheduling for five-axis machining with constraints of the machine tool physical constraints and limits. Compared with other existing numerical methods, the proposed method is able to find an accurate analytical solution for the nonlinear constrained five-axis feedrate scheduling problems without compromising the efficiency of the machining processes.展开更多
We construct a level-1/2 vertex representation of the quantum N-toroidal algebra of type C_(n),which is a natural generalization of the usual quantum toroidal algebra.The construction also provides a vertex representa...We construct a level-1/2 vertex representation of the quantum N-toroidal algebra of type C_(n),which is a natural generalization of the usual quantum toroidal algebra.The construction also provides a vertex representation of the quantum toroidal algebra for type C_(n) as a by-product.展开更多
We consider data exchange for XML documents: given source and target schemas, a mapping between them, and a document conforming to the source schema, construct a target document and answer target queries in a way tha...We consider data exchange for XML documents: given source and target schemas, a mapping between them, and a document conforming to the source schema, construct a target document and answer target queries in a way that is consistent with the source information. The problem has pri- marily been studied in the relational context, in which data- exchange systems have also been built. Since many XML documents are stored in relations, it is natural to consider using a relational system for XML data exchange. However, there is a complexity mismatch between query answering in relational and in XML data exchange. This indicates that to make the use of relational systems pos- sible, restrictions have to be imposed on XML schemas and mappings, as well as on XML shredding schemes. We isolate a set of five requirements that must be ful- filled in order to have a faithful representation of the XML data-exchange problem by a relational translation. We then demonstrate that these requirements naturally suggest the in- lining technique for data-exchange tasks. Our key contribu- tion is to provide shredding algorithms for schemas, docu- ments, mappings and queries, and demonstrate that they en- able us to correctly perform XML data-exchange tasks using a relational system.展开更多
A high-purity Ti(HP-Ti)sheet was subjected to small strain rolling(10%reduction)with microstructural and textural characteristics examined by electron channeling contrast imaging and electron backscatter diffraction t...A high-purity Ti(HP-Ti)sheet was subjected to small strain rolling(10%reduction)with microstructural and textural characteristics examined by electron channeling contrast imaging and electron backscatter diffraction techniques.Particular attentions were paid to misorientation and textural changes aroused by twins in the rolled HP-Ti sheet.Results show that after the 10%rolling,almost all the prior equiaxed grains in the initial specimen are twinned,leading to remarkable grain refinement.The presence of two major misorientation angle peaks around 65°and 85°is ascribed to{11-22}<11-23>and{10-12}<10-11>twinning,respectively,and two minor peaks around 47°and 77°are due mainly to impingement of various variants of such twins.Distinct from earlier work,the small strain rolling is confirmed to be able to induce drastic textural changes in pure Ti sheets:largely reduced texture intensity and appearance of new textural components.This can essentially be attributed to enhanced twinning activity due to much lower impurity contents of the present material.Primary{11?22}twins are mainly responsible for the new textural component of c-axes aligned near the rolling direction with spread,while the component of caxes parallel to the normal direction is due to reorientation of secondary{10-12}twins.This study clearly demonstrates the capability of small strain rolling to effectively modify both microstructures and textures of the HP?Ti sheet and may shed some light on exploring feasible processings for such materials.展开更多
The emerging integrated CPU-GPU architectures facilitate short computational kernels to utilize GPU acceleration. Evidence has shown that, on such systems, the GPU control responsiveness (how soon the host program fi...The emerging integrated CPU-GPU architectures facilitate short computational kernels to utilize GPU acceleration. Evidence has shown that, on such systems, the GPU control responsiveness (how soon the host program finds out about the completion of a GPU kernel) is essential for the overall performance. This study identifies the GPU responsiveness dilemma: host busy polling responds quickly, but at the expense of high energy consumption and interference with co-running CPU programs; interrupt-based notification minimizes energy and CPU interference costs, but suffers from substantial response delay. We present a programlevel solution that wakes up the host program in anticipation of GPU kernel completion. We systematically explore the design space of an anticipatory wakeup scheme through a timerdelayed wakeup or kernel splitting-based pre-completion notification. Experiments show that our proposed technique can achieve the best of both worlds, high responsiveness with low power and CPU costs, for a wide range of GPU workloads.展开更多
We propose a multi-scale modeling framework to investigate the transmission dynamics of cholera. At the population level, we employ a SIR model for the between-host transmission of the disease. At the individual host ...We propose a multi-scale modeling framework to investigate the transmission dynamics of cholera. At the population level, we employ a SIR model for the between-host transmission of the disease. At the individual host level, we describe the evolution of the pathogen within the human body. The between-host and within-host dynamics are connected through an environmental equation that characterizes the growth of the pathogen and its interaction with the hosts outside the human body. We put a special emphasis on the within-host dynamics by making a distinction for each individual host. We conduct both mathematical analysis and numerical simulation for our model in order to explore various scenarios associated with cholera transmission and to better understand the complex, multi-scale disease dynamics.展开更多
Isonitrile group has been identified in many natural products.Due to the broad reactivity of N≡C triple bond,these natural products have valuable pharmaceutical potentials.This review summarizes the current biosynthe...Isonitrile group has been identified in many natural products.Due to the broad reactivity of N≡C triple bond,these natural products have valuable pharmaceutical potentials.This review summarizes the current biosynthetic pathways and the corresponding enzymes that are responsible for isonitrile-containing natural product generation.Based on the strategies utilized,two fundamentally distinctive approaches are discussed.In addition,recent progress in elucidating isonitrile group formation mechanisms is also presented.展开更多
基金the Special Public Sector Fund in Agriculture(200903006)the State Key Laboratory of Animal Nutrition(2004DA125184-0810) of China+3 种基金National Natural Science Foundation of China(NSFC3080078931072040)Ministry of Science and Technology of the People's Republic of China(2006BAD12B05-102009IM03310005)
文摘A total of 335 lactating sows (Landrace x Large White) were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) for mixed parity sows during lactation. In Exp. 1, 185 sows (weighing an average of 256.2 ± 6.5 kg and having an average parity of 3.4 ± 0.3) were allocated to one of six experimental diets in a completely randomized block design within parity groups (1, 2, and 3+). The experimental diets were formulated to contain 3.06, 3.16, 3.20, 3.25, 3.30 or 3.40 Mcal/kg of ME and each diet was fed to the sows throughout a 28 day lactation. All diets provided a similar SID-lysine level (0.86%). As a result, the diets provided a SID-Lys:ME ratio of 2.81, 2.72, 2.69, 2.65, 2.61 or 2.53 g/Mcal ME. Sow feed intake was significantly (P 〈 0.01) affected by the energy content of the diet as well as by sow parity. Using regression analysis, feed intake was shown to be maximized at 3.25, 3.21, 3.21 and 3.21 Mcal/kg of ME for parity 1, 2, 3+ sows and the entire cohort of sows respectively (quadratic; P 〈 0.01). In addition, the result of feed intake can be expressed as 2.65, 2.69, 2.69 and 2.68 g/Mcal based on analysis of SID-Lys:ME ratio. Litter weight gain was affected by dietary treatment for parity 3+ sows and the entire cohort (P 〈 0.01). Based on regression analysis, litter weight gain was maximized at 3.25 and 3.24 Mcal/kg of ME for parity 3+ (quadratic; P 〈 0.01) and the entire cohort (quadratic; P 〈 0.01). Similarly, the result of litter weight gain could be expressed as 2.65 and 2.66 g/Mcal of SID- Lys:ME ratio. Therefore, 3.25 Mcal/kg of ME was selected for Exp. 2 in which 150 sows (weighing 254.6 ± 7.3 kg and having an average parity of 3.4 ± 0.4) were allocated to one of five treatments in a completely randomized block design within parity (1, 2, and 3+). The experimental diets were formulated to contain 2.1, 2.4, 2.7, 3.0 or 3.3 g/Mcal of SID-Lys:ME ratio with all diets providing 3.25 Mcal/kg of ME. The diets were fed to the sows throughout a 28 day lactation. Sow body weight loss was affected by dietary treatment (parity 3+ sows, P = 0.02; entire cohort, P 〈 0.01) and by sow parity (P 〈 0.01). Litter weight at weaning and litter weight gain were affected by dietary treatment for parity 1, 2, 3+ sows and the entire cohort (P 〈 0.01) as well as by sow parity (P 〈 0.01). Plasma urea nitrogen (P 〈 0.01), creatinine (P 〈 0.01) and non-esterifide fatty acids (P = 0.04) were decreased as the SID-Lys:ME ratio of the diet increased. Insulin-like growth factor-1 (P = 0.02), estradiol (P 〈 0.01) and luteinizing hormone (P = 0.02) were increased as the SID-Lys:ME ratio in diet increased. Based on a broken-line model, the estimated SID-Lys: ME ratio to maximize litter weight gain was estimated to be 3.05 g/Mcal.
基金supported in part by the National Natural Science Foundation of China (62222310, U1813201, 61973131, 62033008)the Research Fund for the Taishan Scholar Project of Shandong Province of China+2 种基金the NSFSD(ZR2022ZD34)Japan Society for the Promotion of Science (21K04129)Fujian Outstanding Youth Science Fund (2020J06022)。
文摘In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed performance are demonstrated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating representation.Finally, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.
基金funded by the United States Department of Agriculture (USDA)-APHIS-PPQ-CPHST and North Carolina State University joint project (2012-0195-01)the Special Fund for Agro-Scientific Research in the Public Interest, China (201003067-05)
文摘Huanglongbing (HLB, or citrus greening) is the most destructive disease of citrus, which is associated with Candidatus Liberibacter asiaticus (Las). Few management options are available, aside from preventive measures such as removing infected plants, planting disease-free seedlings, and managing the insect vector. In this study, we assessed the efficacy of thermotherapy against HLB under controlled greenhouse conditions. A total of 60 two-year-old, graft-infected Citrus reticulata Blanco plants were used. The plants were randomly divided into three groups (45℃, 48℃, and untreated control), with five plants/replicate (rep) and four reps/treatment. The treated plants were placed in phytotrons for a 4-h treatment session, repeated once per week for three consecutive weeks. Disease remission was observed eight weeks post-treatment. Real-time PCR assays revealed that Las titers in HLB-affected seedlings were significantly reduced in both 45 and 48℃ treatments four weeks after treatment, with the exception of eight plants. In contrast, Las titers in the untreated control plants increased significantly during the same period, with a maximum increase of 28-fold. Except for seven plants, Las titers in the new flushes of treated plants decreased more than 90% eight weeks after treatment. Las titers in mature leaves of treated plants decreased 56 and 60% in average at 45 and 48℃, respectively, eight weeks after treatment. The HLB symptoms and Las titer of seedings were markedly alleviated eight weeks after treatment in both 45 and 48℃ treatments. Our results laid a good foundation for the further development of citrus free-disease seedling cultivation and Huanglongbing control in the field. The whole plants were replaced for scion or branch in previous as the research object in this study, and the expression of Huanglongbing symptoms combined with real-time polymerase chain reaction (PCR) were used to evaluate the effect of heat treatment in the greenhouse.
文摘AIM: To investigate the effects of lubiprostone and Polyethylene Glycol 3350 (PEG) on mucosal barrier repair in ischernic-injured porcine intestine. METHODS: Ileum from 6 piglets (approximately 15 kg body weight) was subjected to ischemic conditions by occluding the local rnesenteric circulation for 45 min in vivo. Ileal tissues from each pig were then harvested and mounted in Ussing chambers and bathed in oxygenated Ringer's solution in vitro. Intestinal barrier function was assessed by measuring transepithelial electrical resistance (TER) and mucosal-to-serosal fluxes of ^3H-rnannitol and ^14C-inulin. Statistical analyses of data collected over a 120-min time course included 2-way ANOVA for the effects of time and treatment on indices of barrier function. RESULTS: Application of 1μmol/L lubiprostone to the rnucosal surface of ischemic-injured ileum in vitro induced significant elevations in TER compared to nontreated tissue. Lubiprostone also reduced mucosal-toserosal fluxes of ^3H-rnannitol and ^14C-inulin. Alternatively, application of a polyethylene laxative (PEG, 20 rnmol/L) to the mucosal surface of ischernic tissues significantly increased flux of ^3H-rnannitol and ^14C-inulin. CONCLUSION: This experiment demonstrates that lubiprostone stimulates recovery of barrier function in ischemic intestinal tissues whereas the PEG laxative had deleterious effects on mucosal repair. These results suggest that, unlike osmotic laxatives, lubiprostone stimulates repair of the injured intestinal barrier.
基金the National Natural Science Foundation of China under Grant No.90502003JICA Program of"China-Japan Meteorological Disaster Cooperative Research Center"Chinese Major State Basic Research Development Program under Grant 2003CB716806.
文摘By means of varied statistical methods, such as normalized root mean square error (RMSE), correlation analysis, empirical orthogonal function (EOF) decomposition, etc., the reliability of the varied seasonal anomalies of NCEP/NCAR reanalyzed wind speed and surface air temperature (SAT) data frequently used in the climate change research in China is studied. Results show that RMSEs of meteorological variables are smaller in eastern China than in western China, i.e., the reliability of NCEP/NCAR reanalysis in eastern China is better than that in western China. This could be due to effects of the topography in the reanalysis model and the disposition of "dense-in-eastern-and-sparse-in-western" of meteorological stations in China. The RMSE of anomalies of reanalyzed wind speeds decreases with increasing height, further confirming the possible impact of topography on reliability of reanalysis. Results of correlation analysis inversely correspond to those of RMSE analysis, i.e., if the RMSE is larger, the correlation between reanalyzed and observed data is worse, and vice versa. It is found from comparing the EOF eigenvectors of anomaly of reanalyzed and observed data that if a meteorological variable has smaller RMSE, the spatial patterns of corresponding EOF eigenvectors of anomaly of reanalyzed and observed data are similar and their time coefficients are significantly correlated, and vice versa. Therefore, the similarity of EOF modes and" the consistency of their time coefficients can be used to objectively assess the reliability of the reanalysis. On the whole, the reliability of the reanalyzed wind speed is better in spring, summer, and autumn, but worse in winter; and for the reanalyzed SAT, it is the best in winter and the worst in summer.
基金We thank the constructive comments from the anony- mous referees. This material was based upon work supported by DOE Early Career Award, the National Science Foundation (NSF) (1455404 and 1525609), and NSF CAREER Award. This work is also supported partly by the NSF (CNS-1217372, CNS-1239423, CCF-1255729, CNS-1319353, and CNS-1319417) and the National Natural Science Foundation of China (NSFC) (Grant Nos. 61272143, 61272144, and 61472431). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of DOE, NSF, or NSFC.
文摘Recent years have witnessed a processor develop- ment trend that integrates central processing unit (CPU) and graphic processing unit (GPU) into a single chip. The inte- gration helps to save some host-device data copying that a discrete GPU usually requires, but also introduces deep re- source sharing and possible interference between CPU and GPU. This work investigates the performance implications of independently co-running CPU and GPU programs on these platforms. First, we perform a comprehensive measurement that covers a wide variety of factors, including processor ar- chitectures, operating systems, benchmarks, timing mecha- nisms, inputs, and power management schemes. These mea- surements reveal a number of surprising observations. We an- alyze these observations and produce a list of novel insights, including the important roles of operating system (OS) con- text switching and power management in determining the program performance, and the subtle effect of CPU-GPU data copying. Finally, we confirm those insights through case studies, and point out some promising directions to mitigate anomalous performance degradation on integrated heteroge- neous processors.
基金supported by China Postdoctoral Science Foundation(No.2023M741742)the National Key R&D Program of China(No.2023YFD1501600)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent,China(No.2023ZB122)the National Natural Science Foundation of China(No.32371626)。
文摘Plant roots and their associated mycorrhizal fungi critically mediate the decomposition of soil organic carbon(C),but the general patterns of their impacts over a broad geographical range and the primary mediating factors remain unclear.Based on a synthesis of 596 paired observations from both field and greenhouse experiments,we found that living roots and/or mycorrhizal fungi increased organic C decomposition by 30.9%,but low soil nitrogen(N)availability(i.e.,high soil C:N ratio)critically mitigated this promotion effect.In addition,the positive effects of living roots and/or mycorrhizal fungi on organic C decomposition were higher under herbaceous and leguminous plants than under woody and non-leguminous plants,respectively.Surprisingly,there was no significant difference between arbuscular mycorrhizal fungi and ectomycorrhizal fungi in their effects on organic C decomposition.Furthermore,roots and/or mycorrhizal fungi significantly enhanced the decomposition of leaf litter but not root litter.These findings advance our understanding of how roots and their symbiotic fungi modulate soil C dynamics in the rhizosphere or mycorrhizosphere and may help improve predictions of soil global C balance under a changing climate.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12374044, 11904173, 11890703, and 12275133)supported by the Jiangsu Specially-Appointed Professor Program+1 种基金supported by the National Key R&D Project from Ministry of Science and Technology of China (Grant No. 2022YFA1203100)the “Shuangchuang” Doctor Program of Jiangsu Province (Grant No.JSS-CBS20210341)。
文摘Efficient generation of spin polarization is very important for spintronics and quantum computation. In chiral materials without magnetic order nor spin-orbit coupling, we find a new spin selectivity effect—chiral phonon activated spin Seebeck(CPASS)effect. Starting with the nonequilibrium distribution of chiral phonons under a temperature gradient, the CPASS coefficients are computed based on the Boltzmann transport theory. With both the phonon-drag and band transport contributions, the spin accumulations generated by the CPASS effect exhibit quadratic dependence on the temperature gradient. The strength of the CPASS effect and the relative magnitude of both contributions are tunable by the chemical potential modulation. The CPASS effect, which gives a promising explanation on the traditional chiral-induced spin selectivity effect, provides opportunities for the exploration of advanced spintronic devices based on chiral materials even in the absence of any magnetic order and spin-orbit coupling.
基金supported by National Basic Research Program of China(No.2021YFA1201404)National Natural Science Foundation of China(No.32271413)Science program of Jiangsu Province Administration for Market Regulation(No.KJ2024010).
文摘Bacterial cellulose(BC)is an exopolysaccharide with unique properties that has been applied in various fields.However,the dense and intertwined nature of BC fibers limits its use in certain applications,including 3D printing scaffolds for bone regeneration.In this work,a controllable BC-based bio-ink for 3D printing was successfully prepared by modifying the neat BC through maleic acid(MA)treatment,aiming to promote bone tissue regeneration.To achieve homogeneous BC dispersions while preserving its crystalline and chemical properties,BC was modified by MA solution(60%,w/V)with solid-liquid ratio from 1꞉5 to 1꞉50(w/V)to obtain MA-BC dispersions.The analysis results from microstructure,chemical group,crystallinity,and wettability indicated that the BC/MA solution with ratio of 1꞉30 demonstrated the best pre-treatment performance to obtain MA-BC.Subsequently,by combining MA-BC with gelatin,we successfully formulated MA-BC-GEL gels with favorable rheological properties and compression modulus,which can be used as promising bio-inks for 3D bioprinting applications.In vitro tests demonstrated 1꞉30 MA-BC possessed excellent biocompatibility,a significant ability to express the alkaline phosphatase gene and osteogenic-related genes,and facilitated the formation of mineralized nodules.The utilization of this novel bio-ink in scaffold preparation for bone regeneration highlights the promising application of modified BC in bone tissue engineering field.
基金supported by the National Natural Science Foundation of China (Grant No. 51525501)the Science Challenge Project (Grant No. TZ2016006-0102)+1 种基金the Dalian Science and Technology Project (Grant No. 2016RD08)Dr. Y.S. Lee was partially supported by the National Science Foundation (Grant No. CMMI-1547105) to North Carolina State University
文摘In this paper, a new computation method and an optimization algorithm are presented for feedrate scheduling of five-axis machining in compliance with both machine drive limits and process limits. Five-axis machine tool with its ability of controlling tool orientation to follow the sculptured surface contour has been widely used in modern manufacturing industry. Feedrate scheduling serving as a kernel of CNC control system plays a critical role to ensure the required machining accuracy and reliability for five-axis machining. Due to the nonlinear coupling effects of all involved drive axes and the saturation limit of servo motors, the feedrate scheduling for multi-axis machining has long been recognized and remains as a critical challenge for achieving five-axis machine tools’ full capacity and advantage. To solve the nonlinearity nature of the five-axis feedrate scheduling problems, a relaxation mathematical process is presented for relaxing both the drive motors’ physical limitations and the kinematic constraints of five-axis tool motions. Based on the primary optimization variable of feedrate, the presented method analytically linearizes the machining-related constraints, in terms of the machines’ axis velocities, axis accelerations and axis jerks. The nonlinear multi-constrained feedrate scheduling problem is transformed into a manageable linear programming problem. An optimization algorithm is presented to find the optimal feedrate scheduling solution for the five-axis machining problems. Both computer implementation and laboratorial experiment testing by actual machine cutting were conducted and presented in this paper. The experiment results demonstrate that the proposed method can effectively generate efficient feedrate scheduling for five-axis machining with constraints of the machine tool physical constraints and limits. Compared with other existing numerical methods, the proposed method is able to find an accurate analytical solution for the nonlinear constrained five-axis feedrate scheduling problems without compromising the efficiency of the machining processes.
基金N.Jing thanks the support of Simons Foundation grant 523868 and NSFC grant 12171303H.L.Zhang thanks the support of NSFC grant 11871325.
文摘We construct a level-1/2 vertex representation of the quantum N-toroidal algebra of type C_(n),which is a natural generalization of the usual quantum toroidal algebra.The construction also provides a vertex representation of the quantum toroidal algebra for type C_(n) as a by-product.
文摘We consider data exchange for XML documents: given source and target schemas, a mapping between them, and a document conforming to the source schema, construct a target document and answer target queries in a way that is consistent with the source information. The problem has pri- marily been studied in the relational context, in which data- exchange systems have also been built. Since many XML documents are stored in relations, it is natural to consider using a relational system for XML data exchange. However, there is a complexity mismatch between query answering in relational and in XML data exchange. This indicates that to make the use of relational systems pos- sible, restrictions have to be imposed on XML schemas and mappings, as well as on XML shredding schemes. We isolate a set of five requirements that must be ful- filled in order to have a faithful representation of the XML data-exchange problem by a relational translation. We then demonstrate that these requirements naturally suggest the in- lining technique for data-exchange tasks. Our key contribu- tion is to provide shredding algorithms for schemas, docu- ments, mappings and queries, and demonstrate that they en- able us to correctly perform XML data-exchange tasks using a relational system.
基金supported by the Fundamental and Cutting-Edge Research Plan of Chongqing (Grant No. cstc2018jcyjAX0299)the Technology Innovation and Application Demonstration Project of Chongqing (Grant No. cstc2018jszx-cyzdX0080)
文摘A high-purity Ti(HP-Ti)sheet was subjected to small strain rolling(10%reduction)with microstructural and textural characteristics examined by electron channeling contrast imaging and electron backscatter diffraction techniques.Particular attentions were paid to misorientation and textural changes aroused by twins in the rolled HP-Ti sheet.Results show that after the 10%rolling,almost all the prior equiaxed grains in the initial specimen are twinned,leading to remarkable grain refinement.The presence of two major misorientation angle peaks around 65°and 85°is ascribed to{11-22}<11-23>and{10-12}<10-11>twinning,respectively,and two minor peaks around 47°and 77°are due mainly to impingement of various variants of such twins.Distinct from earlier work,the small strain rolling is confirmed to be able to induce drastic textural changes in pure Ti sheets:largely reduced texture intensity and appearance of new textural components.This can essentially be attributed to enhanced twinning activity due to much lower impurity contents of the present material.Primary{11?22}twins are mainly responsible for the new textural component of c-axes aligned near the rolling direction with spread,while the component of caxes parallel to the normal direction is due to reorientation of secondary{10-12}twins.This study clearly demonstrates the capability of small strain rolling to effectively modify both microstructures and textures of the HP?Ti sheet and may shed some light on exploring feasible processings for such materials.
基金We thank the constructive comments from the anonymous referees. This material is based upon work supported by DOE Early Career Award (DE-SC0013700), the National Science Foundation (NSF) (1455404, 1455733 (CAREER), 1525609, 1464216, and 1618912). This work is also supported partly by the National Natural Science Foundation of China (NSFC) (Grant Nos. 61272143, 61272144, 61472431), and National Science and Technology Major Project (NSTMP) (2017ZX01028-101 ). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of DOE, NSF, NSFC or NSTMP.
文摘The emerging integrated CPU-GPU architectures facilitate short computational kernels to utilize GPU acceleration. Evidence has shown that, on such systems, the GPU control responsiveness (how soon the host program finds out about the completion of a GPU kernel) is essential for the overall performance. This study identifies the GPU responsiveness dilemma: host busy polling responds quickly, but at the expense of high energy consumption and interference with co-running CPU programs; interrupt-based notification minimizes energy and CPU interference costs, but suffers from substantial response delay. We present a programlevel solution that wakes up the host program in anticipation of GPU kernel completion. We systematically explore the design space of an anticipatory wakeup scheme through a timerdelayed wakeup or kernel splitting-based pre-completion notification. Experiments show that our proposed technique can achieve the best of both worlds, high responsiveness with low power and CPU costs, for a wide range of GPU workloads.
基金F. Bao was partially supported by the National Science Foundation under Grant No. 1720222. J. Wang was partially supported by the National Science Foundation under Grant Nos. 1412826 and 1557739. The authors are grateful to the two anonymous referees for their valuable comments that have improved this paper.
文摘We propose a multi-scale modeling framework to investigate the transmission dynamics of cholera. At the population level, we employ a SIR model for the between-host transmission of the disease. At the individual host level, we describe the evolution of the pathogen within the human body. The between-host and within-host dynamics are connected through an environmental equation that characterizes the growth of the pathogen and its interaction with the hosts outside the human body. We put a special emphasis on the within-host dynamics by making a distinction for each individual host. We conduct both mathematical analysis and numerical simulation for our model in order to explore various scenarios associated with cholera transmission and to better understand the complex, multi-scale disease dynamics.
基金This work is supported by the Harry C.Kelly Memorial Fund for U.S.-Japan Scientific Cooperation,through the Office of Global Engagementthe NC Japan Center,at NC State University,Natinnal Institute of Health(GM177588 to W.-c.Cr and Y.G.)MOST(2019YFA09005000 and 2018YFA0901900 to J.Z).
文摘Isonitrile group has been identified in many natural products.Due to the broad reactivity of N≡C triple bond,these natural products have valuable pharmaceutical potentials.This review summarizes the current biosynthetic pathways and the corresponding enzymes that are responsible for isonitrile-containing natural product generation.Based on the strategies utilized,two fundamentally distinctive approaches are discussed.In addition,recent progress in elucidating isonitrile group formation mechanisms is also presented.