1 A few decades ago,it was common to see groups of chil-dren riding bikes down quiet American streets.However,this scene is less likely to be seen today.In the 1990s,an average of 20.5 million children aged 7 to 17 ro...1 A few decades ago,it was common to see groups of chil-dren riding bikes down quiet American streets.However,this scene is less likely to be seen today.In the 1990s,an average of 20.5 million children aged 7 to 17 rode bikes six or more times a year,according to the National Sporting Goods Association.By 2023,this number had dropped to about 10.9 million,with less than 5%of them riding frequently.展开更多
Minqin Oasis is located in the lower reaches of the Shiyanghe River Basin, northeast of the Heixi Corridor, at the middle of the Silk Road. Because of the its existence, Badain Jaran Desert and Tengger Desert cannot c...Minqin Oasis is located in the lower reaches of the Shiyanghe River Basin, northeast of the Heixi Corridor, at the middle of the Silk Road. Because of the its existence, Badain Jaran Desert and Tengger Desert cannot converge and develop in the south. It has always been an important green barrier to guarantee the eco-security of Hexi Corridor and the Silk Road for thousands of years. But in recent decades, Minqin Oasis is becoming smaller and the desert is becoming larger. Many people, especially the governmental officials in the lower reaches think that the upper and middle reaches have robbed the lower reaches of water resources, and caused insufficient water usage and the deteriorated eco-environment, in the lower reaches, However, the governmental officials in the upper and middle reaches claim that the whole river basin should take the upper and middle reaches as the key regions to develop economy. To address the above argument, we analyze the reasons why Minqin Oasis is disappearing, and find that there are two main factors. One is the quick development of population and economy in the upper and middle reaches; the other is the rapid development of population and economy in the lower reaches. The two factors both have great effect on the water utilization for eco-environment in the lower reaches. So Minqin Oasis is disappearing not only because of the upper and middle reaches but also because of the growth of population and economy itself. The lower reaches should not completely blame the upper and middle reaches. The upper and middle reaches should also pay more attention to the eco-environment in the lower reaches. The whole river basin should develop a harmonious and sustainable relationship among the upper, middle and lower reaches.展开更多
In this article, the authors deal with the Cauchy problem of a nonlinear parabolic equation with variable density and absorption. By using energy methods, the authors prove that the interfaces can disappear in finite ...In this article, the authors deal with the Cauchy problem of a nonlinear parabolic equation with variable density and absorption. By using energy methods, the authors prove that the interfaces can disappear in finite time under some assumptions on the density functions.展开更多
In this article I discuss data from a series of experiments in which readers’ eye movements were recorded as they processed sentences in which each word disappeared or was masked 60ms after fixation onset. We used th...In this article I discuss data from a series of experiments in which readers’ eye movements were recorded as they processed sentences in which each word disappeared or was masked 60ms after fixation onset. We used this paradigm to investigate whether we could induce a gap effect during reading, and how visual and linguistic factors affected eye movements under these conditions. The data showed that no gap effect occurred in our experiment. Overall reading times were the same under normal and disappearing presentation conditions. However, readers did adopt a strategy of making fewer but longer fixations when the text disappeared than when it did not. Additionally, clear frequency effects occurred regardless of whether the text was presented normally or disappeared. This finding indicates that while the visual uptake of information is important, cognitive processes associated with the lexical identification of words are a primary influence on when readers move their eyes during reading. The findings are taken to support the E-Z Reader model of eye movement control.展开更多
The ipsilateral motor pathway from the unaffected motor cortex to the affected extremity is one of the motor recovery mechanisms following stroke （Jang, 2011）. Because stroke patients who had shown recovery by this ...The ipsilateral motor pathway from the unaffected motor cortex to the affected extremity is one of the motor recovery mechanisms following stroke （Jang, 2011）. Because stroke patients who had shown recovery by this mechanism usually showed poorer motor function, compared with patients who showed recovery by other mechanisms, several researchers have considered this mechanism as a maladaptive plasticity （]ang, 2013）.展开更多
The disappearance of collective flow for <sup>64</sup>Zn+<sup>58</sup>Ni collisions is studied withBUU equation.It is found that the balance energy,E<sub>bal</sub>,is very sensitive...The disappearance of collective flow for <sup>64</sup>Zn+<sup>58</sup>Ni collisions is studied withBUU equation.It is found that the balance energy,E<sub>bal</sub>,is very sensitive to the in-me-dium nucleon-nucleon cross section and increases with the impact parameter.展开更多
In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valencien...In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valenciennes））, big head （Aristichthys nobilis （Richardso）） and lake herring （Coregonus clupeaformis （Mitchill）） that were plankton feeders, common carp （Cyprinus carpio Linnaeus） and crucian carp （Carassius auratus gibelio） belonging to the polyphagia, and also the non-native predator Walleye （Stizostedion vitreum （Mitchill）） and big mouth （Silurus soldatovi rneridonalis Chen）, et al. Among there were not only the cool water fish Peled （Coregonus peled （Gmelin））, but also the warm water fish big mouth. The introduction of non-native fishes resulted in ecosystem changes of the reservoir and some native fishes had gone to decrease their population sizes or been in the condition of depopulation such as Opsariichthys uncirostris arnurensis （Berg）, Rhodeus sericeus （Pallas） and Silurus asotus （Linnaeus）. The native common carp had disappeared after the introduction of non-native species. Roach （Rutilus rutilus lacustris （Pallas） had been thriven for one or two generations after its introduction and immeidiatly disappeared. Silver fish （Protosalanx hyalocranius （Abbott））, Lake herring （Coregonus clupeaformis （Mitchill）） and Walleye （Stizostedion vitreum （Mitchill）） died several years after the introduction, so most of the introduced species has passed out of existence. Via many years introduction of different fishes, composition of species and the structure of the population in the reservoir had been changed obviously. It was necessary to further estimate whether the ecosystem of the reservoir had been damaged.展开更多
Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant f...Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant forage. However, currently no stock- breeders have adopted it as a major forage in China and other countries for a lack of information on the evaluation of nutritional ingredients of leaves and stems of young tetraploid black locust （YTBL） by in situ digesting tests. The objectives of this study were： 1） to assess the nutritive value of YTBL that bourgeoned from root stumps in the spring by determining the ruminal in situ disappearance kinetics of dry matter （DM）, organic matter （OM）, crude protein （CP）, ether extract （EE）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） from leaves, stems and a mixture of both leaves and stems （MLS） of YTBL; 2） to compare these kinetic estimates with those of Leymus chinensis, a widely used ruminant forage in China. All samples were evaluated in situ by using five ruminally cannulated crossbred steers （550±22.7 kg BW）. The results of 48 hours, the representative incubation period, indicate that in situ disappearance rates of DM and OM in YTBL leaves, stems and MLS are on average about 40% and can attain the level of digestibility of L. chinensis. In situ disappearance rates of leaves, stems and MLS of YTBL for CP and EE were 41% and 58% respectively, rates higher than those of L. chinensis. But the disappearance rates of NDF and ADF were, on average, respectively 30.62% and 24.89% and lower than those ofL. chinensis. By analyzing synthetically all of our results it could be inferred that MLS of YTBL offers effective ruminal degradability of DM, NDF, ADF, CP, EE and OM, similar to the nutrients of L. chinensis. This supports our contention that the YTBL leaves, stems and MLS are suitable feed for those ruminants requiring high levels of nutrients, such as dairy cows and Boer goats, instead of plant forage, which is decidedly lacking in some parts of the world.展开更多
BACKGROUND： Some researches are proved that early sitting balance and body motor control performed on patients with stroke and hemiplegia is related to functional prognosis. For patients with hemispatial neglect （HS...BACKGROUND： Some researches are proved that early sitting balance and body motor control performed on patients with stroke and hemiplegia is related to functional prognosis. For patients with hemispatial neglect （HSN） dunng acute stroke, whether HSN disappearance is related to those trainings or not should be further studied. OBJECTIVE： To analyze the correlation between HSN disappearance and related intervention of patients during acute stroke. DESIGN ： Case analysis SETTING ： Department of Neurology, First Affiliated Hospital of Guangxi Medical University PARTICIPANTS： A total of 21 patients with stroke were selected from the Department of Neurology, the First Affiliated Hospital of Guangxi Medical University from May 2005 to March 2006. Diagnosis criteria： ① Stroke was diagnosed by CT and MRI; ② Diagnosis was coincidence with HSN evaluation criteria; ③ All cases were consent. Exclusion cnteda： Patients who had poly-focus, conscious disturbance, severe amentia and hard communication combined with aphasia were excluded. A total of 12 males and 9 females were included, and the mean age was （68±10） years. Among them, 14 patients had cerebral infarction and 7 had cerebral hemorrhage. METHODS： Disappearance and existence of HSN were analyzed with HSN evaluation criteria： body agnosia, left and nght agnosia, maintenance of supine position, place of things, sitting up straight, center of line measured by eyes, and cutting 30 lines with paring method, Items mentioned below belonged to HSN disappearance： ① without body agnosia; ② without left and nght agnosia; ③ be able to maintain supine position; ④ knowing place of things; ⑤ sitting up straight by one＇s own; ⑥ be able to measure the center of line by eyes; ⑦ be able to cut 30 lines with paring method. However, only one item belonged to HSN remnant; but only one item belonged to HSN remnant. Numbers of patients who were of body agnosia, left and nght agnosia and difficult maintenance of supine position were observed during acute period （within 1 week） and recovery period （at 2 weeks after onset）. Related factors with HSN disappearance contained time of physiotherapy, duration of sitting training （sitting in bed and near bedside： heels fallen to ground, feet loaded heavies, center of gravity located at middle line, head raised towards frontage） and hospitalized time. However, control group was not set up.Measurement data were expressed as Mean＋SD and compared with ttest; enumeration data were compared with Chi-square test and Mann-Whitney Utest. P 〈 0.05 was regarded as significant difference. MAIN OUTCOME MEASURES： ① HSN disappearance; ②Numbers of body agnosia, left and right agnosia and difficult maintenance of supine position;③ Correlation among therapeutic time, sitting-training time and hospitalized time. RESULTS： All 21 patients were involved in the final analysis. ① HSN disappearance： Among 21 cases, 2 patients had right HSN disappearance, 19 left HSN disappearance, 8 （38%, 8/21） HSN disappearance, and 13 （62%, 13/21） HSN remnant. Among 8 patients of HSN disappearance, symptoms of 4 cases lasted for 7 days and that of another 4 lasted for 8-12 days. ② Evaluation of HSN disappearance at various phases： Within 1 week, 19% （4/21） HSN patients had body agnosia, left and right agnosia; during recovery period, body agnosia of 20 cases was disappeared and that of 1 case was still survived. Within 1 week, cases with difficult maintenance of supine position were 67% （13/21）, but 43% （17/21） during recovery period. ③ Analysis of effective factors on HSN disappearance and related intervention： At acute phase, HSN disappearance through sitting training lasted for （2.5±1.3） days, and remaining HSN symptoms were relieved for （5.0±3.7） days. There was significant difference between them （ x^2= 3.96, P = 0.039）. The hospitalized time of patients with HSN disappearance and HSN remnant was （17.6±10.4）, （16.2±4.9） days, but there was no significant difference between them （x^2 = 1.41, P = 0.679）. Physiotherapy time of patients with HSN disappearance and HSN remnant was （11.1 ±7.5）, （11.4±4.1 ） days, but there was no significant difference between them （x^2 = 1.05, P = 0.894）. CONCLUSION： Early sitting training may play a possible role in HSN symptom disappearance of patients with stroke.展开更多
An EPR study of paramagnetic centers formed by irradiation of polycrystalline L-α-anhydrous asparagine (L-Asn) was performed. The EPR spectra of gamma irradiated samples at room temperature, shown the presence of thr...An EPR study of paramagnetic centers formed by irradiation of polycrystalline L-α-anhydrous asparagine (L-Asn) was performed. The EPR spectra of gamma irradiated samples at room temperature, shown the presence of three types of paramagnetic centers. A possible mechanisms of formation for the three radical species is suggested, based also on literature data. The kinetics of the disappearance of radicals during thermal annealing indicated a complex mechanism.展开更多
The ancient idea of Heavenly Punishment confused natural phenomena with social issues,which resulted in Zhang Heng’s tragedy in his later years and seismoscope. The instrument might have been lost in the end of the E...The ancient idea of Heavenly Punishment confused natural phenomena with social issues,which resulted in Zhang Heng’s tragedy in his later years and seismoscope. The instrument might have been lost in the end of the Eastern Han Dynasty. A series of extremely serious chaotic social events caused by war took place,such as a fire in Luoyang,forging coins by destroying copper wares,relocation of the capital,sharp population decrease,and the destruction of the Ling Observatory. Zhang’s scientific thought and successful practice had played an important role in ideological enlightenments at the primary stage of modern seismology at the end of the nineteenth century. There is a glorious course of"innovation—inheritance—re-innovation"of scientific and technical development from the inception Zhang Heng’s seismoscope to the modern seismograph invented by Milne,et al.展开更多
In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution an...In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution and population size,and collected data on the tiger skin trade after 1950,the change in subtropical broad-leaved evergreen forest cover,and demographic data in the relevant databases.GIS mapping was used to visualize the distribution range of the South China tiger in Guizhou Province during the period 1900–1980 and to discuss the history of its disappearance in Guizhou and its driving factors.The results show that in 1900,the South China tiger was distributed throughout 82 cities and counties in nine prefectures and municipalities in the province;the number of documented South China tiger distribution sites in 1900–1950 decreased to 48 compared to 1900;the number of counties with South China tigers in 1950–1980 further decreased and became extinct in some areas;and in the 1990s,the South China tiger became extinct in the wild in Guizhou.The main reasons for the extinction of the South China tiger in the wild in Guizhou are:on the one hand,with the socio-economic development of Guizhou Province,the population has increased dramatically,the magnitude of the demand for natural resources has increased,and in order to satisfy this demand,human activities,such as coal mining and clearing of mountains for planting,have been intensified,resulting in the reduction of the coverage rate of the subtropical broad-leaved evergreen forests,which has resulted in the extreme loss of the habitat of the South China tiger;on the other hand,the insufficient protection efforts and protection measures for this species in the country before the 1980s,which were subjected to anthropogenic hunting,were also factors leading to the extinction of this species in the wild in Guizhou Province.As a big cat at the top of the food chain,the distribution of the South China tiger can reflect the history of the natural environment in the region.By analyzing and discussing the distribution history of the South China tiger population in Guizhou Province,the significance of this case is to provide a scientific basis for the future conservation of biodiversity and the development of ecological restoration measures in the karst mountains of southern China.展开更多
The traditional description of the British family is a father, a mother and 2.4 children(on average).However,figures published by the UK government in 2006 revealed that: 66 per cent of marriages in the UK end in divo...The traditional description of the British family is a father, a mother and 2.4 children(on average).However,figures published by the UK government in 2006 revealed that: 66 per cent of marriages in the UK end in divorce,which is the highest rate in展开更多
The objectives of the current study were to compare the difference between standardized ileal digestibility(SID)and standardized total tract digestibility(STTD)of phosphorus(P)in pigs using published data and investig...The objectives of the current study were to compare the difference between standardized ileal digestibility(SID)and standardized total tract digestibility(STTD)of phosphorus(P)in pigs using published data and investigate the factors that affect the hindgut disappearance of P in pigs.A total of 156 observations from 32 experiments that determined the apparent ileal digestibility and total tract digestibility of P in pigs were collected.The SID and STTD of P were calculated by accounting for basal endogenous losses of P.Standardized hindgut disappearance(SHD)of P was determined by subtracting the SID of P from the STTD of P.The Chi-square test was performed to investigate the association between SHD of P and categorical variables,including the use of phytase,the use of inorganic P sources,the use of corn-soybean meal-based diets,and body weight(BW)of pigs.To determine the effects of the SID of P on the SHD of P,a linear equation for the SHD of P was developed using the SID of P as an independent variable.The BWof pigs ranged from 10.0 to 104.8 kg and the SHD of P ranged from22.8%to 39.8%.The STTD of P was greater than the SID of P(47.1%vs.49.7%;P=0.019).Based on the Chi-square analysis,the supplementation of inorganic P sources tended to result in a higher occurrence of a positive value for the SHD of P(P=0.079).In addition,the occurrence of a positive value in the SHD of P was lower when the BWof pigs was below 30 kg.However,as the BWof pigs increased,the occurrence of a positive value in the SHD of P increased(P=0.061).A regression analysis of the SHD of P against the SID of P in pigs indicated that the SHD of P decreased as the SID of P increased in pigs(r2=0.17;P<0.001).In conclusion,the STTD of P is greater than the SID of P in pigs,and the SHD of P depends on the diet composition,the amount of P entering the large intestine,and the BW of the pigs.展开更多
With brilliant civilization during the transitional period from a original clan society to a state society in prehistory,the Neolithic Tenghualuo Site in Lianyungang was discovered by archaeological survey in 1989,whi...With brilliant civilization during the transitional period from a original clan society to a state society in prehistory,the Neolithic Tenghualuo Site in Lianyungang was discovered by archaeological survey in 1989,which was titled as‘one of the nation’s ten great archeological discoveries in 2000’.However,the transgression and the anthropogenic environment deterioration have ever been employed to explain the abandonment of the site.Based on a dynasty framework established by the 14 C dating,and using the experimental methods such as micro-paleontology identification in foraminifera and charophytes, the content test of Rb and Sr,susceptibility analysis as well as granularity and sedimentary facies analysis,some researches on the sediments from the two exploration layers at Tenghualuo Site were conducted,and the following new findings have been gained:Firstly,foraminifera which are relevant to the marine environment were not found in the sediment layer,however,25 charales,which usually live in the freshwater environment,in 07LTT1 exploration samples were found.Among them,3 charales were found in the samples from the forth sediment layer below the late Longshan Cultural layer and 22 charates were from the second sediment layer above the late Longshan Cultural layer.Furthermore,5 plant seeds and 41 fungal spores,together with many carbonation holes,plant seed shells,as well as their roots and stems were also found in the second sediment layer above the late Longshan Cultural layer.Secondly,the cumulative probability curves of the sediments’granularity in both the last and its overlying culture intermittent layers have characteristics of three-phase river sediment curve,and the ratios between Rb and Sr are both quite high in samples from two layers sedimented during the disappearing time of the site.All above-mentioned evidences indicate that disappearance of the Tenghualuo Site was not related to the transgression.The late Longshan Culture of the site could be completely abandoned after a relatively long-term inland water flood.展开更多
Background Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy.Anti-seizure medications(ASMs)are known to have side effects of drug eruption caused by immune responses.A few re...Background Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy.Anti-seizure medications(ASMs)are known to have side effects of drug eruption caused by immune responses.A few reports in adults have demonstrated disappearance of seizures after an ASM drug eruption episode.In this paper,we described 2 cases of childhood absence epilepsy(CAE)who showed seizure disappearance after ethosuximide(ESM)drug eruption,suggesting the possibility that the epilepsy disappears due to immune responses to ASM.Case presentation Case 1 was an 8-year-old girl diagnosed with CAE.She was treated with valproate acid(VPA)initially,and then ESM was administered as an additional treatment.Her epileptic seizure disappeared 4 days after initiation of ESM.However,drug eruption appeared 1 week after the administration of ESM.Even after discontinuation of ESM administration,she maintains no seizure after the drug eruption.Case 2 was a 5-year-old boy diagnosed as CAE.He was treated with VPA initially,and ESM was administered additionally.Drug eruption appeared 1 month after the administration of ESM.Even after ESM was terminated,he maintained seizure freedom after the appearance of eruption.Conclusions Epileptic seizures may have been suppressed due to the immune responses caused by ASM eruption.Further studies are needed to elucidate the pathophysiologic effects of drug eruption on epilepsy through immune responses.展开更多
Traditional bookstores face challenge "As online bookstores become more and more popular,traditional bookstores are disappearing,and a whole attitude and lifestyle is in danger of disappearing with them,"sai...Traditional bookstores face challenge "As online bookstores become more and more popular,traditional bookstores are disappearing,and a whole attitude and lifestyle is in danger of disappearing with them,"said Xue Yuan,author of the book Hello!The Independent Bookstores.展开更多
文摘1 A few decades ago,it was common to see groups of chil-dren riding bikes down quiet American streets.However,this scene is less likely to be seen today.In the 1990s,an average of 20.5 million children aged 7 to 17 rode bikes six or more times a year,according to the National Sporting Goods Association.By 2023,this number had dropped to about 10.9 million,with less than 5%of them riding frequently.
基金the Key Project of National Natural Science Foundation of China(project No.40335049)for financial support.
文摘Minqin Oasis is located in the lower reaches of the Shiyanghe River Basin, northeast of the Heixi Corridor, at the middle of the Silk Road. Because of the its existence, Badain Jaran Desert and Tengger Desert cannot converge and develop in the south. It has always been an important green barrier to guarantee the eco-security of Hexi Corridor and the Silk Road for thousands of years. But in recent decades, Minqin Oasis is becoming smaller and the desert is becoming larger. Many people, especially the governmental officials in the lower reaches think that the upper and middle reaches have robbed the lower reaches of water resources, and caused insufficient water usage and the deteriorated eco-environment, in the lower reaches, However, the governmental officials in the upper and middle reaches claim that the whole river basin should take the upper and middle reaches as the key regions to develop economy. To address the above argument, we analyze the reasons why Minqin Oasis is disappearing, and find that there are two main factors. One is the quick development of population and economy in the upper and middle reaches; the other is the rapid development of population and economy in the lower reaches. The two factors both have great effect on the water utilization for eco-environment in the lower reaches. So Minqin Oasis is disappearing not only because of the upper and middle reaches but also because of the growth of population and economy itself. The lower reaches should not completely blame the upper and middle reaches. The upper and middle reaches should also pay more attention to the eco-environment in the lower reaches. The whole river basin should develop a harmonious and sustainable relationship among the upper, middle and lower reaches.
基金This work is supported in part by NNSF of China(10571126)in part by Program for New Century Excellent Talents in University
文摘In this article, the authors deal with the Cauchy problem of a nonlinear parabolic equation with variable density and absorption. By using energy methods, the authors prove that the interfaces can disappear in finite time under some assumptions on the density functions.
文摘In this article I discuss data from a series of experiments in which readers’ eye movements were recorded as they processed sentences in which each word disappeared or was masked 60ms after fixation onset. We used this paradigm to investigate whether we could induce a gap effect during reading, and how visual and linguistic factors affected eye movements under these conditions. The data showed that no gap effect occurred in our experiment. Overall reading times were the same under normal and disappearing presentation conditions. However, readers did adopt a strategy of making fewer but longer fixations when the text disappeared than when it did not. Additionally, clear frequency effects occurred regardless of whether the text was presented normally or disappeared. This finding indicates that while the visual uptake of information is important, cognitive processes associated with the lexical identification of words are a primary influence on when readers move their eyes during reading. The findings are taken to support the E-Z Reader model of eye movement control.
基金supported by the DGIST R&D Program of the Ministry of Education,Science and Technology of Korea,No.14-BD-0401
文摘The ipsilateral motor pathway from the unaffected motor cortex to the affected extremity is one of the motor recovery mechanisms following stroke （Jang, 2011）. Because stroke patients who had shown recovery by this mechanism usually showed poorer motor function, compared with patients who showed recovery by other mechanisms, several researchers have considered this mechanism as a maladaptive plasticity （]ang, 2013）.
基金The project supported by the Science Foundation of Chinese Academy of Sciences
文摘The disappearance of collective flow for <sup>64</sup>Zn+<sup>58</sup>Ni collisions is studied withBUU equation.It is found that the balance energy,E<sub>bal</sub>,is very sensitive to the in-me-dium nucleon-nucleon cross section and increases with the impact parameter.
文摘In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valenciennes））, big head （Aristichthys nobilis （Richardso）） and lake herring （Coregonus clupeaformis （Mitchill）） that were plankton feeders, common carp （Cyprinus carpio Linnaeus） and crucian carp （Carassius auratus gibelio） belonging to the polyphagia, and also the non-native predator Walleye （Stizostedion vitreum （Mitchill）） and big mouth （Silurus soldatovi rneridonalis Chen）, et al. Among there were not only the cool water fish Peled （Coregonus peled （Gmelin））, but also the warm water fish big mouth. The introduction of non-native fishes resulted in ecosystem changes of the reservoir and some native fishes had gone to decrease their population sizes or been in the condition of depopulation such as Opsariichthys uncirostris arnurensis （Berg）, Rhodeus sericeus （Pallas） and Silurus asotus （Linnaeus）. The native common carp had disappeared after the introduction of non-native species. Roach （Rutilus rutilus lacustris （Pallas） had been thriven for one or two generations after its introduction and immeidiatly disappeared. Silver fish （Protosalanx hyalocranius （Abbott））, Lake herring （Coregonus clupeaformis （Mitchill）） and Walleye （Stizostedion vitreum （Mitchill）） died several years after the introduction, so most of the introduced species has passed out of existence. Via many years introduction of different fishes, composition of species and the structure of the population in the reservoir had been changed obviously. It was necessary to further estimate whether the ecosystem of the reservoir had been damaged.
基金supported by the Ministry of Science and Technology of China (Grant No. 003EFN216700307)the State Forestry Admini-stration of China (No. 2003–5–2)
文摘Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant forage. However, currently no stock- breeders have adopted it as a major forage in China and other countries for a lack of information on the evaluation of nutritional ingredients of leaves and stems of young tetraploid black locust （YTBL） by in situ digesting tests. The objectives of this study were： 1） to assess the nutritive value of YTBL that bourgeoned from root stumps in the spring by determining the ruminal in situ disappearance kinetics of dry matter （DM）, organic matter （OM）, crude protein （CP）, ether extract （EE）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） from leaves, stems and a mixture of both leaves and stems （MLS） of YTBL; 2） to compare these kinetic estimates with those of Leymus chinensis, a widely used ruminant forage in China. All samples were evaluated in situ by using five ruminally cannulated crossbred steers （550±22.7 kg BW）. The results of 48 hours, the representative incubation period, indicate that in situ disappearance rates of DM and OM in YTBL leaves, stems and MLS are on average about 40% and can attain the level of digestibility of L. chinensis. In situ disappearance rates of leaves, stems and MLS of YTBL for CP and EE were 41% and 58% respectively, rates higher than those of L. chinensis. But the disappearance rates of NDF and ADF were, on average, respectively 30.62% and 24.89% and lower than those ofL. chinensis. By analyzing synthetically all of our results it could be inferred that MLS of YTBL offers effective ruminal degradability of DM, NDF, ADF, CP, EE and OM, similar to the nutrients of L. chinensis. This supports our contention that the YTBL leaves, stems and MLS are suitable feed for those ruminants requiring high levels of nutrients, such as dairy cows and Boer goats, instead of plant forage, which is decidedly lacking in some parts of the world.
文摘BACKGROUND： Some researches are proved that early sitting balance and body motor control performed on patients with stroke and hemiplegia is related to functional prognosis. For patients with hemispatial neglect （HSN） dunng acute stroke, whether HSN disappearance is related to those trainings or not should be further studied. OBJECTIVE： To analyze the correlation between HSN disappearance and related intervention of patients during acute stroke. DESIGN ： Case analysis SETTING ： Department of Neurology, First Affiliated Hospital of Guangxi Medical University PARTICIPANTS： A total of 21 patients with stroke were selected from the Department of Neurology, the First Affiliated Hospital of Guangxi Medical University from May 2005 to March 2006. Diagnosis criteria： ① Stroke was diagnosed by CT and MRI; ② Diagnosis was coincidence with HSN evaluation criteria; ③ All cases were consent. Exclusion cnteda： Patients who had poly-focus, conscious disturbance, severe amentia and hard communication combined with aphasia were excluded. A total of 12 males and 9 females were included, and the mean age was （68±10） years. Among them, 14 patients had cerebral infarction and 7 had cerebral hemorrhage. METHODS： Disappearance and existence of HSN were analyzed with HSN evaluation criteria： body agnosia, left and nght agnosia, maintenance of supine position, place of things, sitting up straight, center of line measured by eyes, and cutting 30 lines with paring method, Items mentioned below belonged to HSN disappearance： ① without body agnosia; ② without left and nght agnosia; ③ be able to maintain supine position; ④ knowing place of things; ⑤ sitting up straight by one＇s own; ⑥ be able to measure the center of line by eyes; ⑦ be able to cut 30 lines with paring method. However, only one item belonged to HSN remnant; but only one item belonged to HSN remnant. Numbers of patients who were of body agnosia, left and nght agnosia and difficult maintenance of supine position were observed during acute period （within 1 week） and recovery period （at 2 weeks after onset）. Related factors with HSN disappearance contained time of physiotherapy, duration of sitting training （sitting in bed and near bedside： heels fallen to ground, feet loaded heavies, center of gravity located at middle line, head raised towards frontage） and hospitalized time. However, control group was not set up.Measurement data were expressed as Mean＋SD and compared with ttest; enumeration data were compared with Chi-square test and Mann-Whitney Utest. P 〈 0.05 was regarded as significant difference. MAIN OUTCOME MEASURES： ① HSN disappearance; ②Numbers of body agnosia, left and right agnosia and difficult maintenance of supine position;③ Correlation among therapeutic time, sitting-training time and hospitalized time. RESULTS： All 21 patients were involved in the final analysis. ① HSN disappearance： Among 21 cases, 2 patients had right HSN disappearance, 19 left HSN disappearance, 8 （38%, 8/21） HSN disappearance, and 13 （62%, 13/21） HSN remnant. Among 8 patients of HSN disappearance, symptoms of 4 cases lasted for 7 days and that of another 4 lasted for 8-12 days. ② Evaluation of HSN disappearance at various phases： Within 1 week, 19% （4/21） HSN patients had body agnosia, left and right agnosia; during recovery period, body agnosia of 20 cases was disappeared and that of 1 case was still survived. Within 1 week, cases with difficult maintenance of supine position were 67% （13/21）, but 43% （17/21） during recovery period. ③ Analysis of effective factors on HSN disappearance and related intervention： At acute phase, HSN disappearance through sitting training lasted for （2.5±1.3） days, and remaining HSN symptoms were relieved for （5.0±3.7） days. There was significant difference between them （ x^2= 3.96, P = 0.039）. The hospitalized time of patients with HSN disappearance and HSN remnant was （17.6±10.4）, （16.2±4.9） days, but there was no significant difference between them （x^2 = 1.41, P = 0.679）. Physiotherapy time of patients with HSN disappearance and HSN remnant was （11.1 ±7.5）, （11.4±4.1 ） days, but there was no significant difference between them （x^2 = 1.05, P = 0.894）. CONCLUSION： Early sitting training may play a possible role in HSN symptom disappearance of patients with stroke.
文摘An EPR study of paramagnetic centers formed by irradiation of polycrystalline L-α-anhydrous asparagine (L-Asn) was performed. The EPR spectra of gamma irradiated samples at room temperature, shown the presence of three types of paramagnetic centers. A possible mechanisms of formation for the three radical species is suggested, based also on literature data. The kinetics of the disappearance of radicals during thermal annealing indicated a complex mechanism.
基金sponsored by the National Natural Science Foundation of China(40644019)the Special Found of Scientific Research Program for "the Optimization and Design for Reconstruction Models of Seismoscope",China Earthquake Administration
文摘The ancient idea of Heavenly Punishment confused natural phenomena with social issues,which resulted in Zhang Heng’s tragedy in his later years and seismoscope. The instrument might have been lost in the end of the Eastern Han Dynasty. A series of extremely serious chaotic social events caused by war took place,such as a fire in Luoyang,forging coins by destroying copper wares,relocation of the capital,sharp population decrease,and the destruction of the Ling Observatory. Zhang’s scientific thought and successful practice had played an important role in ideological enlightenments at the primary stage of modern seismology at the end of the nineteenth century. There is a glorious course of"innovation—inheritance—re-innovation"of scientific and technical development from the inception Zhang Heng’s seismoscope to the modern seismograph invented by Milne,et al.
文摘In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution and population size,and collected data on the tiger skin trade after 1950,the change in subtropical broad-leaved evergreen forest cover,and demographic data in the relevant databases.GIS mapping was used to visualize the distribution range of the South China tiger in Guizhou Province during the period 1900–1980 and to discuss the history of its disappearance in Guizhou and its driving factors.The results show that in 1900,the South China tiger was distributed throughout 82 cities and counties in nine prefectures and municipalities in the province;the number of documented South China tiger distribution sites in 1900–1950 decreased to 48 compared to 1900;the number of counties with South China tigers in 1950–1980 further decreased and became extinct in some areas;and in the 1990s,the South China tiger became extinct in the wild in Guizhou.The main reasons for the extinction of the South China tiger in the wild in Guizhou are:on the one hand,with the socio-economic development of Guizhou Province,the population has increased dramatically,the magnitude of the demand for natural resources has increased,and in order to satisfy this demand,human activities,such as coal mining and clearing of mountains for planting,have been intensified,resulting in the reduction of the coverage rate of the subtropical broad-leaved evergreen forests,which has resulted in the extreme loss of the habitat of the South China tiger;on the other hand,the insufficient protection efforts and protection measures for this species in the country before the 1980s,which were subjected to anthropogenic hunting,were also factors leading to the extinction of this species in the wild in Guizhou Province.As a big cat at the top of the food chain,the distribution of the South China tiger can reflect the history of the natural environment in the region.By analyzing and discussing the distribution history of the South China tiger population in Guizhou Province,the significance of this case is to provide a scientific basis for the future conservation of biodiversity and the development of ecological restoration measures in the karst mountains of southern China.
文摘The traditional description of the British family is a father, a mother and 2.4 children(on average).However,figures published by the UK government in 2006 revealed that: 66 per cent of marriages in the UK end in divorce,which is the highest rate in
文摘The objectives of the current study were to compare the difference between standardized ileal digestibility(SID)and standardized total tract digestibility(STTD)of phosphorus(P)in pigs using published data and investigate the factors that affect the hindgut disappearance of P in pigs.A total of 156 observations from 32 experiments that determined the apparent ileal digestibility and total tract digestibility of P in pigs were collected.The SID and STTD of P were calculated by accounting for basal endogenous losses of P.Standardized hindgut disappearance(SHD)of P was determined by subtracting the SID of P from the STTD of P.The Chi-square test was performed to investigate the association between SHD of P and categorical variables,including the use of phytase,the use of inorganic P sources,the use of corn-soybean meal-based diets,and body weight(BW)of pigs.To determine the effects of the SID of P on the SHD of P,a linear equation for the SHD of P was developed using the SID of P as an independent variable.The BWof pigs ranged from 10.0 to 104.8 kg and the SHD of P ranged from22.8%to 39.8%.The STTD of P was greater than the SID of P(47.1%vs.49.7%;P=0.019).Based on the Chi-square analysis,the supplementation of inorganic P sources tended to result in a higher occurrence of a positive value for the SHD of P(P=0.079).In addition,the occurrence of a positive value in the SHD of P was lower when the BWof pigs was below 30 kg.However,as the BWof pigs increased,the occurrence of a positive value in the SHD of P increased(P=0.061).A regression analysis of the SHD of P against the SID of P in pigs indicated that the SHD of P decreased as the SID of P increased in pigs(r2=0.17;P<0.001).In conclusion,the STTD of P is greater than the SID of P in pigs,and the SHD of P depends on the diet composition,the amount of P entering the large intestine,and the BW of the pigs.
基金Supported by National Science and Technology Support Project(Grant No.2006BAK21B02)the Key Project of the National Natural Science Foundation of China(Grant No.90411015)+3 种基金the University Doctoral Foundation(Grant No.20050284011)Foundation of Important Basic Research at Nanjing University(Grant No.0209005206)Open Foundation of the State Key Laboratory of Loess and Quaternary Geology from the Institute of Earth Environment,CAS(Grant No.SKLLQG0503)the Physical Geography of"985"Program of China and the Test Foundation of Modern Analyses Center of Nanjing University(Grant No.0209001309)
文摘With brilliant civilization during the transitional period from a original clan society to a state society in prehistory,the Neolithic Tenghualuo Site in Lianyungang was discovered by archaeological survey in 1989,which was titled as‘one of the nation’s ten great archeological discoveries in 2000’.However,the transgression and the anthropogenic environment deterioration have ever been employed to explain the abandonment of the site.Based on a dynasty framework established by the 14 C dating,and using the experimental methods such as micro-paleontology identification in foraminifera and charophytes, the content test of Rb and Sr,susceptibility analysis as well as granularity and sedimentary facies analysis,some researches on the sediments from the two exploration layers at Tenghualuo Site were conducted,and the following new findings have been gained:Firstly,foraminifera which are relevant to the marine environment were not found in the sediment layer,however,25 charales,which usually live in the freshwater environment,in 07LTT1 exploration samples were found.Among them,3 charales were found in the samples from the forth sediment layer below the late Longshan Cultural layer and 22 charates were from the second sediment layer above the late Longshan Cultural layer.Furthermore,5 plant seeds and 41 fungal spores,together with many carbonation holes,plant seed shells,as well as their roots and stems were also found in the second sediment layer above the late Longshan Cultural layer.Secondly,the cumulative probability curves of the sediments’granularity in both the last and its overlying culture intermittent layers have characteristics of three-phase river sediment curve,and the ratios between Rb and Sr are both quite high in samples from two layers sedimented during the disappearing time of the site.All above-mentioned evidences indicate that disappearance of the Tenghualuo Site was not related to the transgression.The late Longshan Culture of the site could be completely abandoned after a relatively long-term inland water flood.
文摘Background Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy.Anti-seizure medications(ASMs)are known to have side effects of drug eruption caused by immune responses.A few reports in adults have demonstrated disappearance of seizures after an ASM drug eruption episode.In this paper,we described 2 cases of childhood absence epilepsy(CAE)who showed seizure disappearance after ethosuximide(ESM)drug eruption,suggesting the possibility that the epilepsy disappears due to immune responses to ASM.Case presentation Case 1 was an 8-year-old girl diagnosed with CAE.She was treated with valproate acid(VPA)initially,and then ESM was administered as an additional treatment.Her epileptic seizure disappeared 4 days after initiation of ESM.However,drug eruption appeared 1 week after the administration of ESM.Even after discontinuation of ESM administration,she maintains no seizure after the drug eruption.Case 2 was a 5-year-old boy diagnosed as CAE.He was treated with VPA initially,and ESM was administered additionally.Drug eruption appeared 1 month after the administration of ESM.Even after ESM was terminated,he maintained seizure freedom after the appearance of eruption.Conclusions Epileptic seizures may have been suppressed due to the immune responses caused by ASM eruption.Further studies are needed to elucidate the pathophysiologic effects of drug eruption on epilepsy through immune responses.
文摘Traditional bookstores face challenge "As online bookstores become more and more popular,traditional bookstores are disappearing,and a whole attitude and lifestyle is in danger of disappearing with them,"said Xue Yuan,author of the book Hello!The Independent Bookstores.
