In 1979, the Changchun Jingyuetan Remote Sensing Study and Test Site (RSSTS)began its work, and it was formally established in 1985. The RSSTS is subordinated the Changchun Branch of Chinese Academy of Sciences and is...In 1979, the Changchun Jingyuetan Remote Sensing Study and Test Site (RSSTS)began its work, and it was formally established in 1985. The RSSTS is subordinated the Changchun Branch of Chinese Academy of Sciences and is supported by the Changchun Institute of Geography and Changchun Institute of Optics and Fine Machnics, Chinese Academy of Sciences. It is under the management of the Resource & Environment Bureau of Chinese Academy of Sciences and it is the study base of remote sensing basis and application tests in China. The RSSTS is situated in the Jingyuetan scenic spot of the suburbs of Changchun City, Jilin Province. It is located at 43°40′—43°50′N and 125°18′-125°18′E.展开更多
Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor (BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of po...Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor (BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.展开更多
Lactuca sativa, belonging to the Asteraceae family, is a leafy vegetable known for its medicinal properties. This study aimed to understand the mechanism of Lactuca sativa extract with respect to pharmacological actio...Lactuca sativa, belonging to the Asteraceae family, is a leafy vegetable known for its medicinal properties. This study aimed to understand the mechanism of Lactuca sativa extract with respect to pharmacological action. We investigated the anxiolytic effects of hydro-alcoholic extract of leaves of Lactuca sativa on mice. The behav- ioral tests performed on mice models to assess anti-anxiety properties were: open field test (OFT), elevated plus maze test (EPM), elevated T maze test, and marble burying test. Increased locomotor activity and time spent in the "open-ann" were observed in extract fed group. Malondialdehyde (MDA) and nitrite levels were decreased, cata- lase and glutathione levels were increased in Lactuca sativa treated mice. The data obtained in the present study suggests that the extract of Lactuca sativa can afford significant protection against anxiolytic activity.展开更多
Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on fun...Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke:by photothrombosis,focal ischemic lesions were induced in the sensorimotor cortex(SM stroke)or in the peri-prefrontal cortex(peri-PFC stroke).Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke.While ablation of PTP1B in neurons of neuronal knockout(NKO)mice had no effect on the volume or resorption of ischemic lesions,markedly different effects on functional recovery were observed.SM stroke caused severe sensory and motor deficits(adhesive removal test)in wild type and NKO mice at 4 days,but NKO mice showed drastically improved sensory and motor functional recovery at 8 days.In addition,peri-PFC stroke caused anxiety-like behaviors(elevated plus maze and open field tests),and depression-like behaviors(forced swimming and tail suspension tests)in wild type mice 9 and 28 days after stroke,respectively,with minimal effect on sensory and motor function.Peri-PFC stroke-induced affective disorders were associated with fewer active(FosB+)neurons in the PFC and nucleus accumbens but more FosB+neurons in the basolateral amygdala,compared to sham-operated mice.In contrast,mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+neurons after peri-PFC stroke.Taken together,our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke.Thus,PTP1B may represent a novel therapeutic target to improve stroke recovery.All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service(protocol 1806)on July 27,2018.展开更多
BACKGROUND: The orbitofrontal cortex (OFC) is a brain region closely associated with emotion. 5-hydroxytryptamine (5-HT) has been shown to be involved in human depression. OBJECTIVE: To investigate OFC actions a...BACKGROUND: The orbitofrontal cortex (OFC) is a brain region closely associated with emotion. 5-hydroxytryptamine (5-HT) has been shown to be involved in human depression. OBJECTIVE: To investigate OFC actions and mechanisms of 5-HT and 5-HT1A receptor (5-HT1AR) in stress-induced depression.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at Laboratory of Neurobiology, College of Life Science, Shaanxi Normal University between May 2006 and March 2008. MATERIALS: 5-HT, p-chlorophenylalanine (PCPA, an inhibitor to tryptophan hydroxylase) and spiperone (5-HT1AR antagonist) were provided by Sigma, USA; rabbit anti-rat 5-HT1AR antibody was provided by Tianjin Haoyang Biological Manufacture. METHODS: A total of 40 male Sprague Dawley rats, aged 3 months, were randomly divided into five groups: control, model, 5-HT, spiperone + 5-HT, and PCPA, with 8 rats in each group. Except for control group, rats in the other four groups were used to establish depression models by forced swimming for 15 minutes. At 30 minutes before forced swimming test, 0.5 pL of 5-HT (12.5 pg/pL), PCPA (20 pg/pL), spiperone (1.3 pg/pL) + 5-HT (12.5 pg/pL, 10 minutes later), and saline were respectively injected into the OFC of 5-HT, PCPA, spiperone + 5-HT, and model groups, respectively. The control group received a saline microinjection into the OFC.MAIN OUTCOME MEASURES: Forced swimming and open field tests were employed to measure animal behaviors, and immunohistochemistry was used to analyze 5-HT1AR expression in the OFC, cingulate cortex, and piriform cortex. RESULTS: (1) Compared with the model group, 5-HT microinjection into the OFC prominently reduced immobility time in the forced swimming test and rearing in open field test (P 〈 0.05); locomotion and grooming in open field test were increased, although there was no significance (P 〉 0.05). Furthermore, following PCPA microinjection into the OFC (PCPA + forced swimming stress), immobility time in forced swimming test increased dramatically (P〈 0.01), locomotion and rearing in open field test declined (P〈 0.05 and P 〈 0.01, respectively). Compared with the 5-HT group, 5-HT1AR antagonist (spiperone + 5-HT + forced swimming stress) increased immobility time in forced swimming test (P 〈 0.01), but decreased locomotion, rearing, and grooming in open field test. (2) Forced swimming stress markedly elevated 5-HT1AR expression in OFC, cingulate cortex, and piriform cortex (P〈 0.05 or P〈 0.01). CONCLUSION: 5-HT improved stress-induced depression, and 5-HT anti-depression effects are primarily achieved via 5-HT1AR. Stress-induced up regulation of 5-HT1AR expression might be a compensatory mechanism for decreased 5-HT expression.展开更多
The phase modulation and the closed-loop controller can generate electrical crosstalk-coupling in digital closed- loop fibre optic gyro. Four electrical cross-coupling paths are verified by the open-loop testing appro...The phase modulation and the closed-loop controller can generate electrical crosstalk-coupling in digital closed- loop fibre optic gyro. Four electrical cross-coupling paths are verified by the open-loop testing approach. It is found the variation of ramp amplitude will lead to the alternation of gyro bias. The amplitude and the phase parameters of the electrical crosstalk signal are measured by lock-in amplifier, and the variation of gyro bias is confirmed to be caused by the alternation of phase according to the amplitude of the ramp. A digital closed-loop fibre optic gyro electrical crosstalk-coupling model is built by approximating the electrical cross-coupling paths as a proportion and integration segment. The results of simulation and experiment show that the modulation signal electrical crosstalk-coupling can cause the dead zone of the gyro when a small angular velocity is inputted, and it could also lead to a periodic vibration of the bias error of the gyro when a large angular velocity is inputted.展开更多
Cattle temperament is an interesting trait due to its correlation with production efficiency,labor safety,and animal welfare.To date,however,its genetic basis is not clearly understood.Here,we performed a genome-wide ...Cattle temperament is an interesting trait due to its correlation with production efficiency,labor safety,and animal welfare.To date,however,its genetic basis is not clearly understood.Here,we performed a genome-wide association study for a series of temperament traits in cattle,assessed with via open field and novel object tests,using autosomal single nucleotide polymorphisms(SNPs)derived from the whole-genome sequence.We identified 37 and 29 genome-wide significant loci in the open field and novel object tests,respectively.Gene set analysis revealed the most significant pathway was the neuroactive ligand-receptor interaction pathway,which may be essential for emotional control in cattle.Analysis of the expression levels of 18 tissue-specific genes based on transcriptomic data showed enrichment in the brain,with some candidate genes involved in psychiatric and neurodegenerative diseases in humans.Based on principal component analysis,the first principal component explained the largest variance in the open field and novel object test data,and the most significant loci were assigned to SORCS3 and SESTD1,respectively.Our findings should help facilitate cattle breeding for sound temperament by pyramiding favorable alleles to further improve cattle production.展开更多
The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This ...The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This paper is based on the numerical simulation and experimental research of hydrodynamics performance when the propeller is under wave conditions. Open-water propeller performance in calm water is calculated by commercial codes and the results are compared to experimental values to evaluate the accuracy of the numerical simulation method. The first-order Volume of Fluid(VOF) wave method in STAR CCM+ is utilized to simulate the three-dimensional numerical wave. According to the above prerequisite, the numerical calculation of hydrodynamic performance of the propeller under wave conditions is conducted, and the results reveal that both thrust and torque of the propeller under wave conditions reveal intense unsteady behavior. With the periodic variation of waves, ventilation, and even an effluent phenomenon appears on the propeller. Calculation results indicate, when ventilation or effluent appears, the numerical calculation model can capture the dynamic characteristics of the propeller accurately, thus providing a significant theory foundation forfurther studying the hydrodynamic performance of a propeller in waves.展开更多
BACKGROUND:Studies have reported that nitric oxide synthase (NOS) inhibitor can prolong the latency of hyperbaric oxygen-induced convulsion (HBOC). However, there are very few reports addressing the influence of ...BACKGROUND:Studies have reported that nitric oxide synthase (NOS) inhibitor can prolong the latency of hyperbaric oxygen-induced convulsion (HBOC). However, there are very few reports addressing the influence of NOS inhibitor on mental behavior. OBJECTIVE: To investigate behavioral changes after HBOC in gerbils, as well as the influence of NOS inhibitor. DESIGN, TIME AND SETTING: Randomized experiments were performed in the Laboratory of Hyperbaric Pressure and Diving Physiology, Naval Medical Research Institute of Chinese PLA (Shanghai, China) from March 2005 to June 2007. MATERIALS: Forty male gerbils were randomly divided into five groups: HBOC, saline control, NOS inhibitor, pressure control, and normal control. Each group contained eight animals. METHODS: In the HBOC group, once depression induction ended, animals were removed from the chamber five minutes after the first appearance of generalized convulsion induced by 0.5 MPa hyperbaric oxygen. Ten minutes before entering the chamber, saline control and NOS inhibitor animals were intraperitoneally injected with 1 mL saline and 20 mg/kg NG-nitro-L-arginine, respectively. The pressure control group was only exposed to 0.5 MPa. The remaining procedures in these three groups were identical to the HBOC group. The normal control group received no intervention. MAIN OUTCOME MEASURES: Open field test scores in gerbils prior to HBOC, as well as immediately, 24 hours, and 72 hours after decompression ended. RESULTS: HBOC was not detected in either the normal control or the pressure control group, and there were no significant differences in open field test scores prior to and after HBOC (P 〉 0.05). HBOC occurred in the HBOC, saline control, and NOS inhibitor groups, with significant differences in open field test scores after decompression ended compared to normal control and pressure control groups (P 〈 0.05–0.01). Compared to the HBOC and saline control groups, the NOS inhibitor group exhibited a significantly lower score in the open field test immediately after decompression, and a higher score at 24 and 72 hours (P 〈 0.05–0.01). CONCLUSION: NOS inhibitor can regulate behavioral changes in gerbils after HBOC.展开更多
The study of the relationship between animal stress and personality for free-ranging animals is limited and provides contrasting results.The perception of stressors by an individual may vary due to its personality,and...The study of the relationship between animal stress and personality for free-ranging animals is limited and provides contrasting results.The perception of stressors by an individual may vary due to its personality,and certain personality traits may help individuals to better cope with them.Using non-invasive infrared thermography(IRT),we investigated the link between physiological and behavioral components expressed during an acute stress event by free-ranging Fremont’s squirrels(Tamiasciurus fremonti).We expected that,during the acute stress event of being approached by the researcher,individuals that showed a fast pace-of-life syndrome(bolder,more active,and less social/more aggressive)based on an arena test would exhibit stronger sympathetic-adrenal-medullary system reactivity showing a more intense stress-induced hyperthermia(high core body temperature and low peripheral temperature)than individuals with a slow pace of life(shy,less active,and more social).We successfully employed IRT technology to images of Fremont’s squirrels with identification of the individuals’body parts(eye,nose,ear,hind foot).However,we found no support for our hypothesis.Squirrels’body surface temperatures told us more about a squirrel’s external environment and less about the thermal state of the body in that environment following a stressful event.Further studies need to assess how to make IRT effective and efficient in the field and improve its performance in studying the relationships between physiology and personality in wildlife.展开更多
In order to investigate the physiological effects of airport noise exposure on organisms,in this study,we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d.For c...In order to investigate the physiological effects of airport noise exposure on organisms,in this study,we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d.For comparison,we also used unexposed control rats.Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels(LWECPN) of 75 and 80 dB for the two experimental groups.We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine(NE) by high performance liquid chromatography-fluorimetric detection(HPLC-FLD).We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy(TEM).Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number(P<0.05) and significantly longer center area duration(P<0.05) than control animals.After 29 d of airport noise exposure,the concentration of plasma NE of exposed rats was significantly higher than that of the control group(P<0.05).We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d.In conclusion,exposing rats to long-term aircraft noise affects their behaviors,plasma NE levels,and cell morphology of the temporal lobe.展开更多
Background As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number ...Background As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number of epidemiological and experimental studies have demonstrated that ELF MF (50 Hz) exposure is associated with increased risk of various health effects. The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats. Methods The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (MF) was set to 2 mT. Adult rats were divided randomly to control, MF 1 hour and MF 4 hours group. Anxiety-related behaviors were examined in the open field test and the elevated plus maze; changes in spatial learning and memory were determined in Morris water maze aRer 4 weeks of daily exposure. Results Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity. In the Morris water maze test, rats had reduced latency to find the hidden platform and improved long-term memory of former location of platform without changes in short-term memory and locomotor activity. Conclusion Chronic ELF MF exposure has anxiogenic effect on rats, and the promoting effects on spatial learning and long-term retention of spatial memory.展开更多
文摘In 1979, the Changchun Jingyuetan Remote Sensing Study and Test Site (RSSTS)began its work, and it was formally established in 1985. The RSSTS is subordinated the Changchun Branch of Chinese Academy of Sciences and is supported by the Changchun Institute of Geography and Changchun Institute of Optics and Fine Machnics, Chinese Academy of Sciences. It is under the management of the Resource & Environment Bureau of Chinese Academy of Sciences and it is the study base of remote sensing basis and application tests in China. The RSSTS is situated in the Jingyuetan scenic spot of the suburbs of Changchun City, Jilin Province. It is located at 43°40′—43°50′N and 125°18′-125°18′E.
基金supported by a grant from the Experimental Animal Science and Technology Project of Zhejiang Province in China,No.2012C37083
文摘Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor (BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.
文摘Lactuca sativa, belonging to the Asteraceae family, is a leafy vegetable known for its medicinal properties. This study aimed to understand the mechanism of Lactuca sativa extract with respect to pharmacological action. We investigated the anxiolytic effects of hydro-alcoholic extract of leaves of Lactuca sativa on mice. The behav- ioral tests performed on mice models to assess anti-anxiety properties were: open field test (OFT), elevated plus maze test (EPM), elevated T maze test, and marble burying test. Increased locomotor activity and time spent in the "open-ann" were observed in extract fed group. Malondialdehyde (MDA) and nitrite levels were decreased, cata- lase and glutathione levels were increased in Lactuca sativa treated mice. The data obtained in the present study suggests that the extract of Lactuca sativa can afford significant protection against anxiolytic activity.
基金This work was supported by grants from the Heart and Stroke Foundation of Canada(Nos.G-13-0002596&G-18-0022157,to HHCNo.G-16-00014085,to AFRS)+2 种基金the Natural Science and Engineering Research Council of Canada(No.RGPIN/06212-2014,to HHC,No.RGPIN/2016-04985,to AFRS)the Canadian Institutes of Health Research(No.201610PJT,to HHC)HHC is also supported by a Mid-Career Investigator Award(No.7506)from the Heart and Stroke Foundation of Ontario.How to cite this article:Cruz SA。
文摘Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke:by photothrombosis,focal ischemic lesions were induced in the sensorimotor cortex(SM stroke)or in the peri-prefrontal cortex(peri-PFC stroke).Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke.While ablation of PTP1B in neurons of neuronal knockout(NKO)mice had no effect on the volume or resorption of ischemic lesions,markedly different effects on functional recovery were observed.SM stroke caused severe sensory and motor deficits(adhesive removal test)in wild type and NKO mice at 4 days,but NKO mice showed drastically improved sensory and motor functional recovery at 8 days.In addition,peri-PFC stroke caused anxiety-like behaviors(elevated plus maze and open field tests),and depression-like behaviors(forced swimming and tail suspension tests)in wild type mice 9 and 28 days after stroke,respectively,with minimal effect on sensory and motor function.Peri-PFC stroke-induced affective disorders were associated with fewer active(FosB+)neurons in the PFC and nucleus accumbens but more FosB+neurons in the basolateral amygdala,compared to sham-operated mice.In contrast,mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+neurons after peri-PFC stroke.Taken together,our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke.Thus,PTP1B may represent a novel therapeutic target to improve stroke recovery.All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service(protocol 1806)on July 27,2018.
基金the Natural Science Foundation of Shaanxi Province,No. 2006C240
文摘BACKGROUND: The orbitofrontal cortex (OFC) is a brain region closely associated with emotion. 5-hydroxytryptamine (5-HT) has been shown to be involved in human depression. OBJECTIVE: To investigate OFC actions and mechanisms of 5-HT and 5-HT1A receptor (5-HT1AR) in stress-induced depression.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at Laboratory of Neurobiology, College of Life Science, Shaanxi Normal University between May 2006 and March 2008. MATERIALS: 5-HT, p-chlorophenylalanine (PCPA, an inhibitor to tryptophan hydroxylase) and spiperone (5-HT1AR antagonist) were provided by Sigma, USA; rabbit anti-rat 5-HT1AR antibody was provided by Tianjin Haoyang Biological Manufacture. METHODS: A total of 40 male Sprague Dawley rats, aged 3 months, were randomly divided into five groups: control, model, 5-HT, spiperone + 5-HT, and PCPA, with 8 rats in each group. Except for control group, rats in the other four groups were used to establish depression models by forced swimming for 15 minutes. At 30 minutes before forced swimming test, 0.5 pL of 5-HT (12.5 pg/pL), PCPA (20 pg/pL), spiperone (1.3 pg/pL) + 5-HT (12.5 pg/pL, 10 minutes later), and saline were respectively injected into the OFC of 5-HT, PCPA, spiperone + 5-HT, and model groups, respectively. The control group received a saline microinjection into the OFC.MAIN OUTCOME MEASURES: Forced swimming and open field tests were employed to measure animal behaviors, and immunohistochemistry was used to analyze 5-HT1AR expression in the OFC, cingulate cortex, and piriform cortex. RESULTS: (1) Compared with the model group, 5-HT microinjection into the OFC prominently reduced immobility time in the forced swimming test and rearing in open field test (P 〈 0.05); locomotion and grooming in open field test were increased, although there was no significance (P 〉 0.05). Furthermore, following PCPA microinjection into the OFC (PCPA + forced swimming stress), immobility time in forced swimming test increased dramatically (P〈 0.01), locomotion and rearing in open field test declined (P〈 0.05 and P 〈 0.01, respectively). Compared with the 5-HT group, 5-HT1AR antagonist (spiperone + 5-HT + forced swimming stress) increased immobility time in forced swimming test (P 〈 0.01), but decreased locomotion, rearing, and grooming in open field test. (2) Forced swimming stress markedly elevated 5-HT1AR expression in OFC, cingulate cortex, and piriform cortex (P〈 0.05 or P〈 0.01). CONCLUSION: 5-HT improved stress-induced depression, and 5-HT anti-depression effects are primarily achieved via 5-HT1AR. Stress-induced up regulation of 5-HT1AR expression might be a compensatory mechanism for decreased 5-HT expression.
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2007AA04Z436)
文摘The phase modulation and the closed-loop controller can generate electrical crosstalk-coupling in digital closed- loop fibre optic gyro. Four electrical cross-coupling paths are verified by the open-loop testing approach. It is found the variation of ramp amplitude will lead to the alternation of gyro bias. The amplitude and the phase parameters of the electrical crosstalk signal are measured by lock-in amplifier, and the variation of gyro bias is confirmed to be caused by the alternation of phase according to the amplitude of the ramp. A digital closed-loop fibre optic gyro electrical crosstalk-coupling model is built by approximating the electrical cross-coupling paths as a proportion and integration segment. The results of simulation and experiment show that the modulation signal electrical crosstalk-coupling can cause the dead zone of the gyro when a small angular velocity is inputted, and it could also lead to a periodic vibration of the bias error of the gyro when a large angular velocity is inputted.
基金supported by the National Natural Science Foundation of China(31872317)China Agriculture Research System of MOF and MARA(CARS-37)。
文摘Cattle temperament is an interesting trait due to its correlation with production efficiency,labor safety,and animal welfare.To date,however,its genetic basis is not clearly understood.Here,we performed a genome-wide association study for a series of temperament traits in cattle,assessed with via open field and novel object tests,using autosomal single nucleotide polymorphisms(SNPs)derived from the whole-genome sequence.We identified 37 and 29 genome-wide significant loci in the open field and novel object tests,respectively.Gene set analysis revealed the most significant pathway was the neuroactive ligand-receptor interaction pathway,which may be essential for emotional control in cattle.Analysis of the expression levels of 18 tissue-specific genes based on transcriptomic data showed enrichment in the brain,with some candidate genes involved in psychiatric and neurodegenerative diseases in humans.Based on principal component analysis,the first principal component explained the largest variance in the open field and novel object test data,and the most significant loci were assigned to SORCS3 and SESTD1,respectively.Our findings should help facilitate cattle breeding for sound temperament by pyramiding favorable alleles to further improve cattle production.
基金Supported by the National Natural Science Foundation of China (51379043, 41176074, 51209048, 51409063), High Tech Ship Research Project of Ministry of Industry and Technology (G014613002), and the Support Plan for Youth Backbone Teachers of Harbin Engineering University (HEUCFQ 1408)
文摘The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This paper is based on the numerical simulation and experimental research of hydrodynamics performance when the propeller is under wave conditions. Open-water propeller performance in calm water is calculated by commercial codes and the results are compared to experimental values to evaluate the accuracy of the numerical simulation method. The first-order Volume of Fluid(VOF) wave method in STAR CCM+ is utilized to simulate the three-dimensional numerical wave. According to the above prerequisite, the numerical calculation of hydrodynamic performance of the propeller under wave conditions is conducted, and the results reveal that both thrust and torque of the propeller under wave conditions reveal intense unsteady behavior. With the periodic variation of waves, ventilation, and even an effluent phenomenon appears on the propeller. Calculation results indicate, when ventilation or effluent appears, the numerical calculation model can capture the dynamic characteristics of the propeller accurately, thus providing a significant theory foundation forfurther studying the hydrodynamic performance of a propeller in waves.
文摘BACKGROUND:Studies have reported that nitric oxide synthase (NOS) inhibitor can prolong the latency of hyperbaric oxygen-induced convulsion (HBOC). However, there are very few reports addressing the influence of NOS inhibitor on mental behavior. OBJECTIVE: To investigate behavioral changes after HBOC in gerbils, as well as the influence of NOS inhibitor. DESIGN, TIME AND SETTING: Randomized experiments were performed in the Laboratory of Hyperbaric Pressure and Diving Physiology, Naval Medical Research Institute of Chinese PLA (Shanghai, China) from March 2005 to June 2007. MATERIALS: Forty male gerbils were randomly divided into five groups: HBOC, saline control, NOS inhibitor, pressure control, and normal control. Each group contained eight animals. METHODS: In the HBOC group, once depression induction ended, animals were removed from the chamber five minutes after the first appearance of generalized convulsion induced by 0.5 MPa hyperbaric oxygen. Ten minutes before entering the chamber, saline control and NOS inhibitor animals were intraperitoneally injected with 1 mL saline and 20 mg/kg NG-nitro-L-arginine, respectively. The pressure control group was only exposed to 0.5 MPa. The remaining procedures in these three groups were identical to the HBOC group. The normal control group received no intervention. MAIN OUTCOME MEASURES: Open field test scores in gerbils prior to HBOC, as well as immediately, 24 hours, and 72 hours after decompression ended. RESULTS: HBOC was not detected in either the normal control or the pressure control group, and there were no significant differences in open field test scores prior to and after HBOC (P 〉 0.05). HBOC occurred in the HBOC, saline control, and NOS inhibitor groups, with significant differences in open field test scores after decompression ended compared to normal control and pressure control groups (P 〈 0.05–0.01). Compared to the HBOC and saline control groups, the NOS inhibitor group exhibited a significantly lower score in the open field test immediately after decompression, and a higher score at 24 and 72 hours (P 〈 0.05–0.01). CONCLUSION: NOS inhibitor can regulate behavioral changes in gerbils after HBOC.
文摘The study of the relationship between animal stress and personality for free-ranging animals is limited and provides contrasting results.The perception of stressors by an individual may vary due to its personality,and certain personality traits may help individuals to better cope with them.Using non-invasive infrared thermography(IRT),we investigated the link between physiological and behavioral components expressed during an acute stress event by free-ranging Fremont’s squirrels(Tamiasciurus fremonti).We expected that,during the acute stress event of being approached by the researcher,individuals that showed a fast pace-of-life syndrome(bolder,more active,and less social/more aggressive)based on an arena test would exhibit stronger sympathetic-adrenal-medullary system reactivity showing a more intense stress-induced hyperthermia(high core body temperature and low peripheral temperature)than individuals with a slow pace of life(shy,less active,and more social).We successfully employed IRT technology to images of Fremont’s squirrels with identification of the individuals’body parts(eye,nose,ear,hind foot).However,we found no support for our hypothesis.Squirrels’body surface temperatures told us more about a squirrel’s external environment and less about the thermal state of the body in that environment following a stressful event.Further studies need to assess how to make IRT effective and efficient in the field and improve its performance in studying the relationships between physiology and personality in wildlife.
基金Project supported by the National Natural Science Foundation of China (No. 1060408)the National Public Benefit Research Foundation of China (No. 200809142)
文摘In order to investigate the physiological effects of airport noise exposure on organisms,in this study,we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d.For comparison,we also used unexposed control rats.Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels(LWECPN) of 75 and 80 dB for the two experimental groups.We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine(NE) by high performance liquid chromatography-fluorimetric detection(HPLC-FLD).We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy(TEM).Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number(P<0.05) and significantly longer center area duration(P<0.05) than control animals.After 29 d of airport noise exposure,the concentration of plasma NE of exposed rats was significantly higher than that of the control group(P<0.05).We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d.In conclusion,exposing rats to long-term aircraft noise affects their behaviors,plasma NE levels,and cell morphology of the temporal lobe.
文摘Background As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number of epidemiological and experimental studies have demonstrated that ELF MF (50 Hz) exposure is associated with increased risk of various health effects. The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats. Methods The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (MF) was set to 2 mT. Adult rats were divided randomly to control, MF 1 hour and MF 4 hours group. Anxiety-related behaviors were examined in the open field test and the elevated plus maze; changes in spatial learning and memory were determined in Morris water maze aRer 4 weeks of daily exposure. Results Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity. In the Morris water maze test, rats had reduced latency to find the hidden platform and improved long-term memory of former location of platform without changes in short-term memory and locomotor activity. Conclusion Chronic ELF MF exposure has anxiogenic effect on rats, and the promoting effects on spatial learning and long-term retention of spatial memory.