The distribution and diversity of the species are closely related to the global climate.As the most widely distributed species of Bufonidae in China,the study of the distribution pattern and habitat suitability of the...The distribution and diversity of the species are closely related to the global climate.As the most widely distributed species of Bufonidae in China,the study of the distribution pattern and habitat suitability of the Asiatic toad under climate change can help us understand the reply pattern of Bufonidae habitat to climate change.Here,combined with the Maxent model and GIS technology,the effects of climate change on the distribution pattern and habitat suitability of the Asiatic toad were comprehensively analyzed.The results show that the rainfall during the wettest season(Bio16)and the mean temperature of the driest season(Bio9)have a considerable impact on the distribution of the Asiatic toad.In the next 30 to 50 years,across the overall spacial scale of the Chinese mainland,the habitat of the Asiatic toad will be primarily in the eastern part of China and less in south part,while its distribution area will expand to the midwest and northwest parts of China.Overall,the area in which it can be distributed will be reduced and suitable habitat will shift to some regions of higher latitude and elevation.In a word,we systematically analyzed the changes of the distribution pattern and habitat suitability of the Asiatic toad with climate change,and we aim to provide data on how climatic variation may impact amphibians.展开更多
[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobuf...[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin) in toad skin. [Results] Chromatographic conditions are as follows: Agilent ZORBAX SB-C 18 chromatographic column was used;acetonitrile (A)-0.3% glacial acetic acid (B) gradient elution (0-15 min, 28%A-54%A;15-35 min, 54%A-54%A) was conducted;the flow rate was 0.6 mL/min;the detection wavelength was 296 nm;the column temperature was 30 ℃;the sample size was 10 μL. Under the above conditions, the determination method of the five components can be established at one time. [Conclusions] The method was stable and reliable, and can provide experimental basis for the development and utilization of active ingredients in toad skin.展开更多
Trypanosomiasis afflicts about 6~7 million people globally and to a large extent impedes livestock production in Africa.Naturally,trypanosomal parasites undergo genetic mutation and have developed resistance over a wi...Trypanosomiasis afflicts about 6~7 million people globally and to a large extent impedes livestock production in Africa.Naturally,trypanosomal parasites undergo genetic mutation and have developed resistance over a wide range of therapies.The utilization of animals and plants products has presented therapeutic potential for identifying novel anti-trypanosomal drugs.This study evaluated toad venom for anti-trypanosomal potency in-vivo in Swiss mice.Toads were collected from July to August 2019.The acute oral toxicity and biochemical characterization of the toad venom were determined.The experimental mice were administered various doses(130 mg/kg,173 mg/kg and 217 mg/kg)of the toad venom crude extract and 0.75 mg/mL of Diamizan Plus standard drug for the treatment of trypanosomiasis,once daily for 3 days.The in-vivo anti-trypanosomal activity was evaluated by a curative test,after infecting the mice with Trypanosoma brucei brucei.The pre-patent period was 72 hours before treatment commenced.The overall results showed that trypanosomal load was highest in the control group while the group treated with Diamizan drug had the least trypanosomal load.As such,the mean trypanosomal load in relation to treatments showed a very high significant difference(P<0.05).Also,the mean trypanosomal load in Swiss mice in relation to the highest dosage of toad venom versus Diamizan drug showed a very high significant difference(P<0.05).The mean change in relation to the haematological parameters across treatments groups varied significantly(P<0.05)with the exception of Hb which showed no significant difference(P>0.05)across treatment groups.The over 50%reduction in the trypanosomal load in the 130 mg/kg group in comparison with the control group brings to bare the anti-trypanosomal potency of the toad venom.The anti-trypanosomal activity demonstrated by the toad venom has provided basis for development of new therapeutic agents from different toad species.The study recommends further studies(both in-vivo and in-vitro)followed by the characterization of the active compounds present in the toad venom responsible for the anti-tyrpanosomal activity observed alongside the management and conservation of these species.展开更多
The present study used a microelectronic neural bridge comprised of electrode arrays for neural signal detection, functional electrical stimulation, and a microelectronic circuit including signal amplifying, processin...The present study used a microelectronic neural bridge comprised of electrode arrays for neural signal detection, functional electrical stimulation, and a microelectronic circuit including signal amplifying, processing, and functional electrical stimulation to bridge two separate nerves, and to restore the lost function of one nerve. The left leg of one spinal toad was subjected to external mechanical stimulation and functional electrical stimulation driving. The function of the left leg of one spinal toad was regenerated to the corresponding leg of another spinal toad using a microelectronic neural bridge. Oscilloscope tracings showed that the electromyographic signals from controlled spinal toads were generated by neural signals that controlled the spinal toad, and there was a delay between signals. This study demonstrates that microelectronic neural bridging can be used to restore neural function between different injured nerves.展开更多
A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic varia...A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.展开更多
Mating preferences are common in natural populations of animals.Numerous studies have shown that male mate choice can occur in a wide range of taxa.However,male mating preferences are still poorly understood in anuran...Mating preferences are common in natural populations of animals.Numerous studies have shown that male mate choice can occur in a wide range of taxa.However,male mating preferences are still poorly understood in anurans.Sexual selection theory predicts that male mate choice is not expected to arise if 1) adult population exhibited a highly male-biased sex ratio which will diminish male mating success;2) males provide less parental care;3) mating success of males is associated with chorus tenure in which males would maximize their fitness by mating with multiple mates.We tested these predictions in the Asian common toad Duttaphrynus melanostictus from southeastern Tibet,China.Our field experimental results indicated that,the breeding population exhibited a highly male-biased sex ratio,called males did not defend sites which contain significant resources required by females and offspring,both sexes provided no parental care after egg-laying,and the toad species was characterized with prolonged breeding season chorus attendance.In male mate choice experiment,males did not show preferences for a larger gravid female over a smaller gravid female.We suggest that male mating success in the Asian common toad is likely determined by the number but not the quality of mates.Future research should focus on how sexual selection on male acoustic signaling and how female preference exert different types of selection pressure on male call traits in this Tibet toad.展开更多
We propose and experimentally demonstrate a novel all-optical non-return-to-zero differential-phase-shift-keying （NRZ-DPSK） to return-to-zero differentiM-phase-shift-keying （RZ-DPSK） format conversion scheme. This...We propose and experimentally demonstrate a novel all-optical non-return-to-zero differential-phase-shift-keying （NRZ-DPSK） to return-to-zero differentiM-phase-shift-keying （RZ-DPSK） format conversion scheme. This scheme is based on the terahertz optical asymmetric demultiplexer （TOAD）. A 10 Gb/s converted RZ-DPSK signal is obtained with a wide duty cycle tuning range from 16% to 66%. For all converted RZ-DPSK signals, the receiver sensitivities at BER of 10-9 are 0.4 to 1.7dB higher compared with the original NRZ-DPSK signal. The clear and open eye diagrams are presented to demonstrate the high quality format conversion performance. Moreover, the optical spectra show that this conversion is in a wavelength-preserving operation.展开更多
The conflict and congruity of dualistic approaches to the world inundate the illustration of agricultural production in the Pre-Columbian Art of the Maya.Crop production is co-dependent on human factors,environmental ...The conflict and congruity of dualistic approaches to the world inundate the illustration of agricultural production in the Pre-Columbian Art of the Maya.Crop production is co-dependent on human factors,environmental factors and animal factors.The symbiosis of these elements generated success or failure in harmony with the natural world.This paper explores the relationship of three animals to successful crop production with particular attention placed on the cane toad,as this creature has often been confused with frogs or underplayed in earlier academic research.The cane toad is a powerful force in organic farming,functioning as a deterrent to destructive pests.In addition,the cane toad produces powerful hallucinogenic substances for humans,while at the same time,repelling predators with its bitter taste,acrid smell and poison.This bufo-toxin is a powerful substance that links the toad with the Underworld origins of the maize.展开更多
Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August ...Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P guinanensis. Our results indicated that the sex ratio of males to females was 1：2.8. Males had a lower survival rate （6%） than females （14%） across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.展开更多
Various designed circuits for multiple-valued all-optical arithmetic are demonstrated. The terahertz-optical-asymmetric-demultiplexer (TOAD) switch is used as the basic structure unit in the proposed circuits due to i...Various designed circuits for multiple-valued all-optical arithmetic are demonstrated. The terahertz-optical-asymmetric-demultiplexer (TOAD) switch is used as the basic structure unit in the proposed circuits due to its compact size, thermal stability, and low power operation. The designs of trinary and quaternary signed-digit numbers based adders are presented using different polarized states of light. These proposed polarization-encoded based adders use much less switches and their speeds are higher than the intensity-encoded counterparts. Further, it will be shown that one of the proposed trinary signed-digit adders is twice as fast as a recently reported modified signed-digit adder.展开更多
文摘The distribution and diversity of the species are closely related to the global climate.As the most widely distributed species of Bufonidae in China,the study of the distribution pattern and habitat suitability of the Asiatic toad under climate change can help us understand the reply pattern of Bufonidae habitat to climate change.Here,combined with the Maxent model and GIS technology,the effects of climate change on the distribution pattern and habitat suitability of the Asiatic toad were comprehensively analyzed.The results show that the rainfall during the wettest season(Bio16)and the mean temperature of the driest season(Bio9)have a considerable impact on the distribution of the Asiatic toad.In the next 30 to 50 years,across the overall spacial scale of the Chinese mainland,the habitat of the Asiatic toad will be primarily in the eastern part of China and less in south part,while its distribution area will expand to the midwest and northwest parts of China.Overall,the area in which it can be distributed will be reduced and suitable habitat will shift to some regions of higher latitude and elevation.In a word,we systematically analyzed the changes of the distribution pattern and habitat suitability of the Asiatic toad with climate change,and we aim to provide data on how climatic variation may impact amphibians.
基金Supported by the Self-funded Research Project of Administration of Traditional Chinese Medicine of Guangxi Zhuang Autonomous Region(GXZYZ20210078)Key Research and Development Project of Guangxi Science and Technology Department(Guike AB19110003).
文摘[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin) in toad skin. [Results] Chromatographic conditions are as follows: Agilent ZORBAX SB-C 18 chromatographic column was used;acetonitrile (A)-0.3% glacial acetic acid (B) gradient elution (0-15 min, 28%A-54%A;15-35 min, 54%A-54%A) was conducted;the flow rate was 0.6 mL/min;the detection wavelength was 296 nm;the column temperature was 30 ℃;the sample size was 10 μL. Under the above conditions, the determination method of the five components can be established at one time. [Conclusions] The method was stable and reliable, and can provide experimental basis for the development and utilization of active ingredients in toad skin.
文摘Trypanosomiasis afflicts about 6~7 million people globally and to a large extent impedes livestock production in Africa.Naturally,trypanosomal parasites undergo genetic mutation and have developed resistance over a wide range of therapies.The utilization of animals and plants products has presented therapeutic potential for identifying novel anti-trypanosomal drugs.This study evaluated toad venom for anti-trypanosomal potency in-vivo in Swiss mice.Toads were collected from July to August 2019.The acute oral toxicity and biochemical characterization of the toad venom were determined.The experimental mice were administered various doses(130 mg/kg,173 mg/kg and 217 mg/kg)of the toad venom crude extract and 0.75 mg/mL of Diamizan Plus standard drug for the treatment of trypanosomiasis,once daily for 3 days.The in-vivo anti-trypanosomal activity was evaluated by a curative test,after infecting the mice with Trypanosoma brucei brucei.The pre-patent period was 72 hours before treatment commenced.The overall results showed that trypanosomal load was highest in the control group while the group treated with Diamizan drug had the least trypanosomal load.As such,the mean trypanosomal load in relation to treatments showed a very high significant difference(P<0.05).Also,the mean trypanosomal load in Swiss mice in relation to the highest dosage of toad venom versus Diamizan drug showed a very high significant difference(P<0.05).The mean change in relation to the haematological parameters across treatments groups varied significantly(P<0.05)with the exception of Hb which showed no significant difference(P>0.05)across treatment groups.The over 50%reduction in the trypanosomal load in the 130 mg/kg group in comparison with the control group brings to bare the anti-trypanosomal potency of the toad venom.The anti-trypanosomal activity demonstrated by the toad venom has provided basis for development of new therapeutic agents from different toad species.The study recommends further studies(both in-vivo and in-vitro)followed by the characterization of the active compounds present in the toad venom responsible for the anti-tyrpanosomal activity observed alongside the management and conservation of these species.
基金supported by the National Natural Science Foundation of China,No,90707005,61001046 and 61204018the Natural Science Foundation of Education Department of Jiangsu Province,No.11KJB510023the Special Foundation and Open Foundation of State Key Laboratory of Bioelectronics of Southeast University,No.2011E05
文摘The present study used a microelectronic neural bridge comprised of electrode arrays for neural signal detection, functional electrical stimulation, and a microelectronic circuit including signal amplifying, processing, and functional electrical stimulation to bridge two separate nerves, and to restore the lost function of one nerve. The left leg of one spinal toad was subjected to external mechanical stimulation and functional electrical stimulation driving. The function of the left leg of one spinal toad was regenerated to the corresponding leg of another spinal toad using a microelectronic neural bridge. Oscilloscope tracings showed that the electromyographic signals from controlled spinal toads were generated by neural signals that controlled the spinal toad, and there was a delay between signals. This study demonstrates that microelectronic neural bridging can be used to restore neural function between different injured nerves.
文摘A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.
基金supported by the Joint Funds for Fostering Talents of NSFC and the People's Government of Henan Province(No.U1304309)National Sciences Foundation of China(No.31501870, No.31670392 and No.31872216)+2 种基金Natural Sciences Foundation for Distinguished Young Scholar of Sichuan (No.2016JQ0038)Key Foundation of Sichuan Provincial Department of Education (No.18ZA0255)Technology Foundation for Selected Overseas Chinese Scholar (No.HGQD02)。
文摘Mating preferences are common in natural populations of animals.Numerous studies have shown that male mate choice can occur in a wide range of taxa.However,male mating preferences are still poorly understood in anurans.Sexual selection theory predicts that male mate choice is not expected to arise if 1) adult population exhibited a highly male-biased sex ratio which will diminish male mating success;2) males provide less parental care;3) mating success of males is associated with chorus tenure in which males would maximize their fitness by mating with multiple mates.We tested these predictions in the Asian common toad Duttaphrynus melanostictus from southeastern Tibet,China.Our field experimental results indicated that,the breeding population exhibited a highly male-biased sex ratio,called males did not defend sites which contain significant resources required by females and offspring,both sexes provided no parental care after egg-laying,and the toad species was characterized with prolonged breeding season chorus attendance.In male mate choice experiment,males did not show preferences for a larger gravid female over a smaller gravid female.We suggest that male mating success in the Asian common toad is likely determined by the number but not the quality of mates.Future research should focus on how sexual selection on male acoustic signaling and how female preference exert different types of selection pressure on male call traits in this Tibet toad.
文摘We propose and experimentally demonstrate a novel all-optical non-return-to-zero differential-phase-shift-keying （NRZ-DPSK） to return-to-zero differentiM-phase-shift-keying （RZ-DPSK） format conversion scheme. This scheme is based on the terahertz optical asymmetric demultiplexer （TOAD）. A 10 Gb/s converted RZ-DPSK signal is obtained with a wide duty cycle tuning range from 16% to 66%. For all converted RZ-DPSK signals, the receiver sensitivities at BER of 10-9 are 0.4 to 1.7dB higher compared with the original NRZ-DPSK signal. The clear and open eye diagrams are presented to demonstrate the high quality format conversion performance. Moreover, the optical spectra show that this conversion is in a wavelength-preserving operation.
文摘The conflict and congruity of dualistic approaches to the world inundate the illustration of agricultural production in the Pre-Columbian Art of the Maya.Crop production is co-dependent on human factors,environmental factors and animal factors.The symbiosis of these elements generated success or failure in harmony with the natural world.This paper explores the relationship of three animals to successful crop production with particular attention placed on the cane toad,as this creature has often been confused with frogs or underplayed in earlier academic research.The cane toad is a powerful force in organic farming,functioning as a deterrent to destructive pests.In addition,the cane toad produces powerful hallucinogenic substances for humans,while at the same time,repelling predators with its bitter taste,acrid smell and poison.This bufo-toxin is a powerful substance that links the toad with the Underworld origins of the maize.
基金supported by the National Natural Science Foundation of China (31372183, 31772447, 31471988)
文摘Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P guinanensis. Our results indicated that the sex ratio of males to females was 1：2.8. Males had a lower survival rate （6%） than females （14%） across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.
文摘Various designed circuits for multiple-valued all-optical arithmetic are demonstrated. The terahertz-optical-asymmetric-demultiplexer (TOAD) switch is used as the basic structure unit in the proposed circuits due to its compact size, thermal stability, and low power operation. The designs of trinary and quaternary signed-digit numbers based adders are presented using different polarized states of light. These proposed polarization-encoded based adders use much less switches and their speeds are higher than the intensity-encoded counterparts. Further, it will be shown that one of the proposed trinary signed-digit adders is twice as fast as a recently reported modified signed-digit adder.
