I love dogs because they are so friendly and lovely.With bright eyes,dogs can see things in the dark.Their noses are very sensitive,and this helps them find things easily.My pet dog is named Dahu.He is white with long...I love dogs because they are so friendly and lovely.With bright eyes,dogs can see things in the dark.Their noses are very sensitive,and this helps them find things easily.My pet dog is named Dahu.He is white with long ears.Every day when I come back home from school,he runs to me happily and wags his tail.We often play games together.He likes to chase a ball,and I throw the ball far,then he runs quickly to bring it back.展开更多
在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,...在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,它的诞生糅合了神话想象与历史现实,成为英语文化中一道独特的语言风景。展开更多
Social learning is a mechanism used by many species to effciently gain information about their environment.Although many animals live in an environment where members of other species are present,little is known about ...Social learning is a mechanism used by many species to effciently gain information about their environment.Although many animals live in an environment where members of other species are present,little is known about interspecifc social learning.Domesticated and urbanized species provide the opportunity to investigate whether nonhuman animals can learn from heterospecifcs such as humans,who are integral parts of their social landscape.Although domestic dogs Canis familiaris have been intensively researched for their ability to learn from humans,most studies have focused on dogs living as pets.However,free-ranging dogs represent the majority of the world’s dog population,they live alongside humans,scavenge on human refuse,and are subject to natural and sexual selection.Thus,free-ranging dogs with extensive exposure to humans and their artifacts provide the opportunity to investigate interspecifc social learning in a naturalistic setting,where learning from humans might be a beneft for them.Here we tested individual free-ranging dogs in a between-subject design:Dogs in the control group could spontaneously choose between two novel and differently patterned food-delivering boxes.In the experimental group,instead,dogs could frst observe an unfamiliar human approaching and eating from 1 of the 2 boxes.We provide the frst evidence that free-ranging dogs match the choice of an unfamiliar human.These results show that at least simple forms of interspecifc social learning might be involved in dogs’success in living alongside humans in a complex urbanized environment.展开更多
Some animals have the capacity to produce different alarm calls for terrestrial and aerial predators. However, it is not clear what cognitive processes are involved in generating these calls. One possibility is the po...Some animals have the capacity to produce different alarm calls for terrestrial and aerial predators. However, it is not clear what cognitive processes are involved in generating these calls. One possibility is the position of the predator： Anything on the ground receives a terrestrial predator call, and anything in the air receives an aerial predator call. Another possibility is that animals are able to recognize the physical features of predators and incorporate those into their calls. As a way of elucidating which of these mechanisms plays a primary role in generating the structure of different calls, we performed two field experiments with Gunnison＇s prairie dogs. First, we presented the prairie dogs with a circle, a triangle, and a square, each moving across the colony at the same height and speed. Second, we presented the prairie dogs with two squares of differing sizes. DFA statistics showed that 82.6 percent of calls for the circle and 79.2 percent of the calls for the triangle were correctly classified, and 73.3 percent of the calls for the square were classified as either square or circle. Also, 100 percent of the calls for the larger square and 90 percent of the calls for the smaller square were correctly classified. Because both squares and circles are features of terrestrial predators and triangles are features of aerial predators, our results suggest that prairie dogs might have a cognitive mechanism that labels the abstract shape and size of different predators, rather than the position of the predator [Current Zoology 58 （5）： 741-748, 2012].展开更多
Jumping sun dogs are rapid light flashes changing over clouds, with some of them located close to the places of halo formation in thunder storms clouds. This paper presents an outline of some aspects that are required...Jumping sun dogs are rapid light flashes changing over clouds, with some of them located close to the places of halo formation in thunder storms clouds. This paper presents an outline of some aspects that are required for understanding the jumping sun dogs, using some experiments with light scattering in complex fluids. In our analogy, we have observed the jumping laser dogs, in which the ice crystals are replaced by needlelike structures of ferrofluid, the electric field in the atmosphere is represented by an external magnetic field, and the laser beam scattered by the ferrofluid structure has the same role of the sun as the source of light scattered by the ice crystals subjected to changing electric fields in thunderstorm clouds.展开更多
We developed an HPLC method to study the pharmacokinetics ofpuerarin in Beagle dogs after oral administration of puerarin or puerarin mixed micelles （PMMS）. Beagle dogs were divided into two groups randomly, and the...We developed an HPLC method to study the pharmacokinetics ofpuerarin in Beagle dogs after oral administration of puerarin or puerarin mixed micelles （PMMS）. Beagle dogs were divided into two groups randomly, and the blood samples were collected at fixed time intervals after single oral administration ofpuerarin or PMMS at a dosage of 120 mg/kg. Following sample preparation, analytes were separated on a C18 column （DIKMA, 150 mm×4.6 mm, 5 μm） with a guard column （DIKMA, 8 mm×4 mm） and eluted with methanol-water （25：75, v/v）. Theophylline was used as the internal standard. WinNonlin 6.1 （Pharsight, USA） was used to calculate the pharrnacokinetic parameters. The pharmacokinetic parameters for puerarin and PMMS in Beagle dogs were as follows： AUC, 515.96 and 2796.43 min μg/mL; Tmax, 61.48 and 202.91 min; CL/F, 232.58 and 42.91 mL/min/kg, respectively. The relative bioavailability of PMMS to puerarin was 542.0%. Our results showed that the mixed micelle preparation significantly improved the bioavailability of puerarin by delaying absorption and reducing clearance.展开更多
Domestic cats and dogs are carnivores that have evolved differentially in the nutrition and metabolism of amino acids.This article highlights both proteinogenic and nonproteinogenic amino acids.Dogs inadequately synth...Domestic cats and dogs are carnivores that have evolved differentially in the nutrition and metabolism of amino acids.This article highlights both proteinogenic and nonproteinogenic amino acids.Dogs inadequately synthesize citrulline(the precursor of arginine)from glutamine,glutamate,and proline in the small intestine.Although most breeds of dogs have potential for adequately converting cysteine into taurine in the liver,a small proportion(1.3%-2.5%)of the Newfoundland dogs fed commercially available balanced diets exhibit a deficiency of taurine possibly due to gene mutations.Certain breeds of dogs(e.g.,golden retrievers)are more prone to taurine deficiency possibly due to lower hepatic activities of cysteine dioxygenase and cysteine sulfinate decarboxylase.De novo synthesis of arginine and taurine is very limited in cats.Thus,concentrations of both taurine and arginine in feline milk are the greatest among domestic mammals.Compared with dogs,cats have greater endogenous nitrogen losses and higher dietary requirements for many amino acids(e.g.,arginine,taurine,cysteine,and tyrosine),and are less sensitive to amino acid imbalances and antagonisms.Throughout adulthood,cats and dogs may lose 34%and 21%of their lean body mass,respectively.Adequate intakes of high-quality protein(i.e.,32%and 40%animal protein in diets of aging dogs and cats,respectively;dry matter basis)are recommended to alleviate aging-associated reductions in the mass and function of skeletal muscles and bones.Pet-food grade animal-sourced foodstuffs are excellent sources of both proteinogenic amino acids and taurine for cats and dogs,and can help to optimize their growth,development,and health.展开更多
The pharmacokinetics and absolute bioavailability of the sublingual naloxone tablet were studied with HPLC-electrochemical detection. Eight male dogs received single 5 mg dose of naloxone intravenously, the plasma con...The pharmacokinetics and absolute bioavailability of the sublingual naloxone tablet were studied with HPLC-electrochemical detection. Eight male dogs received single 5 mg dose of naloxone intravenously, the plasma concentration-time curves could be fitted to two-compartment open model, with 12.0 min of t1/2( , 143.4 min of t1/2( and 7.92 mg(min/L of AUC. The same eight dogs received 5 mg dose of the sublingual naloxone tablet after an interval of a week. The main pharmacokinetic parameters were: t1/2ka = 11.0 min, t1/2( = 15.4 min, t1/2( = 164.1 min, Tmax = 27.7 min, Cmax = 34.2 ng / ml, and AUC = 6.79 mg(min / L, respectively. The plasma concentration-time curves were fitted to the first order absorption two-compartment open model also. The mean absolute bioavailability of the sublingual naloxone tablet was 86.8 ( 10.9%. No statistically significant differences were found with t1/2(, t1/2(, ( and ( between the two routes of administration. These results indicated that the course of disposition for naloxone in dogs was similar for the two routes of administration, and the absolute bioavailability of the sublingual naloxone tablet was high. Thus satisfactory clinical effects could be expected.展开更多
Objective:To evaluate the Anaplasma phagocytophilum(A.phagocytophilum),Ehrlichia canis(E.canis,Dirofilaria immitis(D.immitis)(canine heartworm),Borrelia burgdorferi(B.burgdorferi)infections in countryside dogs from Yu...Objective:To evaluate the Anaplasma phagocytophilum(A.phagocytophilum),Ehrlichia canis(E.canis,Dirofilaria immitis(D.immitis)(canine heartworm),Borrelia burgdorferi(B.burgdorferi)infections in countryside dogs from Yunnan,Hainan and Anhui provinces.Methods:Serum samples were collected from 26 dogs in Yunnan.Hainan and Anhui provinces.The samples were tested using a commercial ELISA rapid diagnostic assay kit(SNAP^(?)4Dx^(?);IDEXX Laboratories,Inc.U.S.A.).Meaiiwliile,indirect immunofluorescence assay(IFA)recommended by WHO was conducted to delect IgG to A.phagocytophilum.Two methods were analyzed and compared.Results:The number of serologically positive dogs for IgG to A.phagocytophilum was only 2which was from Hainan province and none of the 26 dogs responded positive for E.canu.D.immitis(canine heartworm,and B.burgdorferi by ELISA rapid diagnostic method.The number of serologically positive dogs for IgG to A.phagocytophilum was 13(50%)by IFA method.Data of the two methods were analyzed by statistical software and the difference was statistically significant(P=0.002).Conclusions:It can be concluded that IFA method was more sensitive than ELISA rapid diagnostic method.However,we need conduct further and intensive epidemiology survey on tick-born diseases pathogens including.4.phagocytophilum,E.canis,D.immitis(canine heartworm),and B.burgdorferi which have public health significance.展开更多
Objective:To evaluate clinical and hematological aspects of dogs naturally infected with Hepatozoon canis(H.canis)presented at the Small Animal Clinics of Guru Angad Dev Veterinary and Animal Sciences University,Ludhi...Objective:To evaluate clinical and hematological aspects of dogs naturally infected with Hepatozoon canis(H.canis)presented at the Small Animal Clinics of Guru Angad Dev Veterinary and Animal Sciences University,Ludhiana.Methods:Blood films of 34 naturally infected dogs were examined for haematological alterations and parasitaemia.Signalment and clinical signs were recorded from the animals.Clinical histories were filled oul during the consultation.Results:Of the 34 positive dogs by Giemsa stained peripheral blood films.88.23%presented parasilaemia by H.canis only,while 11.77%had the combination of H.canis,Babesia sp.and Ehrlichia sp.Young male dogs less than oue-year-old,of nondescript breed,were the most commonly affected.And 26.47%were presented with anorexia/inappetence as the only clinical symptom.Other clinical symptoms were mild to moderate fever,pale mucosae and lethargy;a few were also showing the signs of vomiting and diarrhoea.Haematological alterations showed mainly normochromic-normocytic anaemia,leukocytosis and neutrophilia.Conclusions:The findings of this study substantiate that H.canis caused clinical and haematological alterations of the varied intensity in dogs,even with low parasilaemia.should he taken into consideration.展开更多
Hypoxia represents one of the most extreme environmental conditions for both human beings and animals living at high al- titudes （Zhao et al., 2009）. Over the past few years, great attention has been focused on the ...Hypoxia represents one of the most extreme environmental conditions for both human beings and animals living at high al- titudes （Zhao et al., 2009）. Over the past few years, great attention has been focused on the genetic bases of adaption to high-altitude environments （Bigham et al., 2010; Simonson et al., 2010）. The domestic dog （Canisfamiliaris） is the first animal that developed an intimate relationship with human beings. Dogs migrated with human beings and have adapted to variety of ecological niches （Savolainen et al., 2002）. Our previous research revealed parallel evolution and convergent evolution in the adaptation of dogs and humans to the high-altitude environment of the Tibetan plateau （Wang et al., 2013, 2014）, suggesting that exploring the adaption of domestic dogs to high-altitude hypoxia is an interesting and important question.展开更多
Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-strand...Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014;Ge et al. 2018).展开更多
OBJECTIVE:To investigate the radioprotective ef fect of tea polyphenols(TP 50)against radiation-in duced organ and tissue damage.METHODS:Beagle dogs were exposed to a single acute dose of whole-body y-radiation(3 Gy)a...OBJECTIVE:To investigate the radioprotective ef fect of tea polyphenols(TP 50)against radiation-in duced organ and tissue damage.METHODS:Beagle dogs were exposed to a single acute dose of whole-body y-radiation(3 Gy)and orally administered TP 50(80 or 240 mg·kg-1·d-1)for 28 consecutive days.A hemogram was obtained from experimental dogs every other day for 42 d.At the end of the experiment,enzyme activities of the antioxidants superoxide-dismutase and glutathione peroxidase,serum levels of inflammatory cytokines(tumor necrosis factor-a,interleukin-1β,and interleukin-6),colony-forming units of bone marrow hematopoietic progenitor cells,and organ coefficients were measured.RESULTS:Dogs exposed to γ-radiation alone exhibited typical hematopoietic syndrome.In contrast,irradiated dogs that received TP 50 exhibited an improved blood profile with reduced leucopenia,thrombocytopenia(platelet counts),and reticulocyte levels.TP 50 also significantly elevated levels of the endogenous antioxidant enzyme superoxide-dismutase,reduced the increased levels of serum cytokine in response to radiation-induced toxicity,and increased colony-forming units of bone marrow hematopoietic progenitor cells.In addition,TP 50 repaired radiation-induced organ damage.CONCLUSION:The current findings suggest that oral administration of TP 50 to beagle dogs effectively alleviated hematopoietic bone marrow damage induced by y-radiation.展开更多
OBJECTIVE To compare the pharmacokinetics and pharmacodynamics of PEG30-rhG-CSF administered to beagle dogs at three different dosages with PEG20-rhG-CSF administered at one dosage, and to provide an experimental basi...OBJECTIVE To compare the pharmacokinetics and pharmacodynamics of PEG30-rhG-CSF administered to beagle dogs at three different dosages with PEG20-rhG-CSF administered at one dosage, and to provide an experimental basis for clinical trials.METHODS Beagle dogs received single, subcutaneous doses of PEG30-rhG-CSF at 100, 200 and 400 μg/kg or PEG20-rhG-CSF at 200 μg/kg. PEG30-rhG-CSF and PEG20-rhG-CSF concentrations in serum were analyzed using an enzymeqinked immunosorbent assay （ELISA）. WBC, ANC and PLT counts of whole blood samples were measured using fully automated analytic instrumentation. Pharmacokinetic and pharmacodynamic parameters were calculated using DAS 2.0 statistical analysis software.METHODS Beagle dogs received single, subcutaneous doses of PEG30-rhG-CSF at 100, 200 and 400 μg/kg or PEG20-rhG-CSF at 200μg/kg. PEG30-rhG-CSF and PEG20-rhG-CSF concentrations in serum were analyzed using an enzyme-linked immunosorbent assay （ELISA）. WBC, ANC and PLT counts of whole blood samples were measured using fully automated analytic instrumentation. Pharmacokinetic and pharmacodynamic parameters were calculated using DAS 2.0 statistical analysis software. RESULTS The pharmacokinetic parameters of PEG30-rhG-CSF calculated from the serum concentration data determined by ELISA were as follows： the mean elimination half-life （t1/2ke） was 40.6 h （33.5-45.4 h）; the mean time to reach peak concentration （Tmax） was 19.2 h （11.7-24.0 h）; the drug clearance from the serum （CL） was decreased with increasing doses; the peak concentration （Cmax） and the area under the serum concentration-time curve （AUC） were increased with increasing doses. For PEG20-rhG- CSF, the half-life was shorter （12 h） and Tmax was achieved much earlier （10 h） relative to PEG30-rhG-CSF. The AUC of PEG30- rhG-CSF was much greater than that of PEG20-rhG-CSF, and the relative bioavailability with a subcutaneous injection was 158.7%. Administration of single doses of PEG30-rhG-CSF resulted in substantial increases in the absolute The time to reach ANC （ANCTmax） neutrophil count （ANC）. was 72 h. The maximum observed absolute neutrophil counts （ANCmax） and the area over the baseline effect curve （AOBEC） was increased with increasing doses. The effect-elimination half-life （t1/2E） ranged from 60 h to 80 h after subcutaneous administration. The PLT count was slightly elevated 8-12 h after s.c. injection, and declined after 24 h. CONCLUSION The mean elimination half-life of PEG30-rhG- CSF was longer than that of PEG20-rhG-CSF at the same dose, and the other main pharmacokinetic and pharmacodynamic parameters of PEG30-rhG-CSF, including C ANCmax, AUC and AOBEC were much greater than those following PEG20-rhG-CSF injection.展开更多
Background： During sperm maturation, there is a reorganization of fatty acids from plasmatic membrane of the spermatozoa, which allows higher membrane integrity and acquisition of sperm motility. However, the fatty a...Background： During sperm maturation, there is a reorganization of fatty acids from plasmatic membrane of the spermatozoa, which allows higher membrane integrity and acquisition of sperm motility. However, the fatty acid profile during sperm maturation remains unclear in dogs. Thus, the aim of this study was to identify the fatty acids from the epididymal spermatozoa and plasma during the sperm maturation, and observed changes in the motility and plasmatic membrane parameters. Twenty one adult dogs were used, subsequently to bilateral orchiectomy and epididymal storage, sperm samples were collected from the different segments of the epididymis. Samples were evaluated for conventional microscopy, computer-assisted motility analysis, sperm plasma membrane permeability and the fatty acid analysis（lipids were extracted, transmethylated and analyzed by chromatography）.Results： Caput and corpus sperm showed lower values for the motility variables evaluated and plasmatic membrane integrity, indicating different levels of the fatty acids organization. Saturated, monounsaturated and polyunsaturated fatty acids were in higher concentrations in the spermatozoa from epididymis cauda. Highlighting the presence of caprylic, stearic and docosahexaenoic acids.Conclusions： These findings demonstrate the influence of the fatty acid profile during sperm maturation, assigning physical and chemical changes in sperm cells, essential for fertilization.展开更多
Didanosine is an effective antiviral drug in untreated and antiretroviral therapy-experienced patients with Human Immunodeficiency Virus (HIV). An automated system using on-line solid extraction and High Performance L...Didanosine is an effective antiviral drug in untreated and antiretroviral therapy-experienced patients with Human Immunodeficiency Virus (HIV). An automated system using on-line solid extraction and High Performance Liquid Chromatography (HPLC) with ultraviolet (UV) detection was developed and validated for pharmacokinetic analysis of didanosine in dog plasma. Modifications were introduced on a previous methodology for simultaneous analysis of antiretroviral drugs in human plasma. Extraction was carried out on C18 cartridges, with high extraction yield as stationary phase, whereas mobile phase consisted of a mixture of 0.02 M potassium phosphate buffer, acetonitrile (KH2PO4: acetonitrile: 96:4, v/v) and 0.5% (w/v) of heptane sulphonic acid. The pH was adjusted to 6.5 with triethylamine. All samples and standard solutions were chromatographed at 28 1C. For an isocratic run, the fiux was 1.0 mL/min, detection was at 250 nm and injected volume was 20 mL. The method was selective and linear for concentrations between 50 and 5000 ng/mL. Drug stability data ranged from 96% to 98%, and limit of quantification was 25 ng/mL. Extraction yield was up to 95%. Drug stability in dog plasma was kept frozen at 20 1C for one month after three freeze–thaw cycles, and for 24 h after processing in the auto sampler. Assay was successfully applied to measure didanosine concentrations in plasma dogs.展开更多
The goal of this study was to evaluate the influence of natural variation in the regenerative status of dog tissues on the signs of hormesis, which are evident after total body exposure to low daily doses of external ...The goal of this study was to evaluate the influence of natural variation in the regenerative status of dog tissues on the signs of hormesis, which are evident after total body exposure to low daily doses of external gamma radiation throughout the lifespan. Ninety beagle dogs of both sexes were irradiated with cobalt 60 at 0.003 Gy/day commencing 1 year after birth to death. Control (n = 169) and irradiated animals underwent whole-life clinical observation and autopsy, and were then retrospectively divided into two subgroups with (W) or without benign tumors or tumors of unknown nature (WO) that were clinically recorded on single days throughout the lifespan. Radiation hormesis was only detected in subgroup WO, which had life span (LS) of 10.7 years in the absence of radiation. The radiogenic prolongation of life to 11.8 years in the WO subgroup (p 【0.05) was similar to that in the W control and irradiated W subgroups (11.8 and 11.5 years, respectively). The number of solid malignancies found upon autopsy of the control WO subgroup was less (39.5%) than that evident in the control W subgroup (60%). Compared to the irradiated W subgroup, irradiation of the WO subgroup was accompanied by a slight increase (1.14-fold) in the number of solid malignancies evident at autopsy and in the clinical signs of tissue atrophy and body weight loss (2.4-fold and 2.4-fold, respectively), but was accompanied by strong reductions in the extent of anemia and hemoblastoses (】10-fold for both). The data exclude the notion that radiation is associated with healing, but suggest that certain pathologies (e.g., hemoblastoses) may be substituted with other less dangerous somatic diseases in weaker animals only.展开更多
Feline panleukopenia virus(FPV)is a single-stranded DNA virus that can infect cats and cause feline panleukopenia,which is a highly contagious and fatal disease in felines.The sequence of FPV is highly variable,and mu...Feline panleukopenia virus(FPV)is a single-stranded DNA virus that can infect cats and cause feline panleukopenia,which is a highly contagious and fatal disease in felines.The sequence of FPV is highly variable,and mutations in the amino acids of its capsid protein play crucial roles in altering viral virulence,immunogenicity,host selection,and other abilities.In this study,the epidemiology of FPV was studied using 746 gastrointestinal swab samples derived from cats that presented gastrointestinal symptoms specifcally,diarrhea or vomiting during the period spanning from 2018 to 2022.The overall prevalence of FPV-positive patients among these samples was determined to be 45.4%.Capsid(virion)protein 2(VP2)gene of each FPV-positive sample was sequenced and amplifed,yielding 65 VP2 sequences.Among them,six VP2 gene sequences were detected in the majority of the samples test positive for FPV,and these positive samples originated from a diverse range of geographical locations.These isolates were named FPV-6,FPV-10,FPV-15,FPV-251,FPV-271 and FPV-S2.Additionally,the substitution of Ala300Pro(A300P)in VP2 was detected for the frst time in feline-derived FPV(FPV-251).FPV-251 isolate,with this substitution in VP2 protein,exhibited stable proliferative capacity in Madin-Darby canine kidney(MDCK)cells and A72 cells.FPV-271 was selected as the FPV control isolate due to its single amino acid diference from VP2 protein of FPV-251 at position 300(FPV-271 has alanine,while FPV-251 has proline).After oral infection,both FPV-251 and FPV-271 isolates caused feline panleukopenia,which is characterized by clinical signs of enterocolitis.However,FPV-251 can infect dogs through the oral route and cause gastrointestinal(GI)symptoms with lesions in the intestine and mesenteric lymph nodes(MLNs)of infected dogs.This is the frst report on the presence of an A300P substitution in VP2 protein of feline-derived FPV.Additionally,FPV isolate with a substitution of A300P at VP2 protein demonstrated efcient replication capabilities in canine cell lines and the ability to infect dogs.展开更多
文摘I love dogs because they are so friendly and lovely.With bright eyes,dogs can see things in the dark.Their noses are very sensitive,and this helps them find things easily.My pet dog is named Dahu.He is white with long ears.Every day when I come back home from school,he runs to me happily and wags his tail.We often play games together.He likes to chase a ball,and I throw the ball far,then he runs quickly to bring it back.
文摘在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,它的诞生糅合了神话想象与历史现实,成为英语文化中一道独特的语言风景。
文摘Social learning is a mechanism used by many species to effciently gain information about their environment.Although many animals live in an environment where members of other species are present,little is known about interspecifc social learning.Domesticated and urbanized species provide the opportunity to investigate whether nonhuman animals can learn from heterospecifcs such as humans,who are integral parts of their social landscape.Although domestic dogs Canis familiaris have been intensively researched for their ability to learn from humans,most studies have focused on dogs living as pets.However,free-ranging dogs represent the majority of the world’s dog population,they live alongside humans,scavenge on human refuse,and are subject to natural and sexual selection.Thus,free-ranging dogs with extensive exposure to humans and their artifacts provide the opportunity to investigate interspecifc social learning in a naturalistic setting,where learning from humans might be a beneft for them.Here we tested individual free-ranging dogs in a between-subject design:Dogs in the control group could spontaneously choose between two novel and differently patterned food-delivering boxes.In the experimental group,instead,dogs could frst observe an unfamiliar human approaching and eating from 1 of the 2 boxes.We provide the frst evidence that free-ranging dogs match the choice of an unfamiliar human.These results show that at least simple forms of interspecifc social learning might be involved in dogs’success in living alongside humans in a complex urbanized environment.
文摘Some animals have the capacity to produce different alarm calls for terrestrial and aerial predators. However, it is not clear what cognitive processes are involved in generating these calls. One possibility is the position of the predator： Anything on the ground receives a terrestrial predator call, and anything in the air receives an aerial predator call. Another possibility is that animals are able to recognize the physical features of predators and incorporate those into their calls. As a way of elucidating which of these mechanisms plays a primary role in generating the structure of different calls, we performed two field experiments with Gunnison＇s prairie dogs. First, we presented the prairie dogs with a circle, a triangle, and a square, each moving across the colony at the same height and speed. Second, we presented the prairie dogs with two squares of differing sizes. DFA statistics showed that 82.6 percent of calls for the circle and 79.2 percent of the calls for the triangle were correctly classified, and 73.3 percent of the calls for the square were classified as either square or circle. Also, 100 percent of the calls for the larger square and 90 percent of the calls for the smaller square were correctly classified. Because both squares and circles are features of terrestrial predators and triangles are features of aerial predators, our results suggest that prairie dogs might have a cognitive mechanism that labels the abstract shape and size of different predators, rather than the position of the predator [Current Zoology 58 （5）： 741-748, 2012].
文摘Jumping sun dogs are rapid light flashes changing over clouds, with some of them located close to the places of halo formation in thunder storms clouds. This paper presents an outline of some aspects that are required for understanding the jumping sun dogs, using some experiments with light scattering in complex fluids. In our analogy, we have observed the jumping laser dogs, in which the ice crystals are replaced by needlelike structures of ferrofluid, the electric field in the atmosphere is represented by an external magnetic field, and the laser beam scattered by the ferrofluid structure has the same role of the sun as the source of light scattered by the ice crystals subjected to changing electric fields in thunderstorm clouds.
基金Foundation of Independent Subject of Beijing University of Chinese Medicine (Grant No. JYB22-JS025)Compound Chinese Medicine Preparation Research Innovation Team (Team No. 2011-CXTD-13)
文摘We developed an HPLC method to study the pharmacokinetics ofpuerarin in Beagle dogs after oral administration of puerarin or puerarin mixed micelles （PMMS）. Beagle dogs were divided into two groups randomly, and the blood samples were collected at fixed time intervals after single oral administration ofpuerarin or PMMS at a dosage of 120 mg/kg. Following sample preparation, analytes were separated on a C18 column （DIKMA, 150 mm×4.6 mm, 5 μm） with a guard column （DIKMA, 8 mm×4 mm） and eluted with methanol-water （25：75, v/v）. Theophylline was used as the internal standard. WinNonlin 6.1 （Pharsight, USA） was used to calculate the pharrnacokinetic parameters. The pharmacokinetic parameters for puerarin and PMMS in Beagle dogs were as follows： AUC, 515.96 and 2796.43 min μg/mL; Tmax, 61.48 and 202.91 min; CL/F, 232.58 and 42.91 mL/min/kg, respectively. The relative bioavailability of PMMS to puerarin was 542.0%. Our results showed that the mixed micelle preparation significantly improved the bioavailability of puerarin by delaying absorption and reducing clearance.
基金This work was supported by Texas A&M AgriLife Research(H-8200).
文摘Domestic cats and dogs are carnivores that have evolved differentially in the nutrition and metabolism of amino acids.This article highlights both proteinogenic and nonproteinogenic amino acids.Dogs inadequately synthesize citrulline(the precursor of arginine)from glutamine,glutamate,and proline in the small intestine.Although most breeds of dogs have potential for adequately converting cysteine into taurine in the liver,a small proportion(1.3%-2.5%)of the Newfoundland dogs fed commercially available balanced diets exhibit a deficiency of taurine possibly due to gene mutations.Certain breeds of dogs(e.g.,golden retrievers)are more prone to taurine deficiency possibly due to lower hepatic activities of cysteine dioxygenase and cysteine sulfinate decarboxylase.De novo synthesis of arginine and taurine is very limited in cats.Thus,concentrations of both taurine and arginine in feline milk are the greatest among domestic mammals.Compared with dogs,cats have greater endogenous nitrogen losses and higher dietary requirements for many amino acids(e.g.,arginine,taurine,cysteine,and tyrosine),and are less sensitive to amino acid imbalances and antagonisms.Throughout adulthood,cats and dogs may lose 34%and 21%of their lean body mass,respectively.Adequate intakes of high-quality protein(i.e.,32%and 40%animal protein in diets of aging dogs and cats,respectively;dry matter basis)are recommended to alleviate aging-associated reductions in the mass and function of skeletal muscles and bones.Pet-food grade animal-sourced foodstuffs are excellent sources of both proteinogenic amino acids and taurine for cats and dogs,and can help to optimize their growth,development,and health.
文摘The pharmacokinetics and absolute bioavailability of the sublingual naloxone tablet were studied with HPLC-electrochemical detection. Eight male dogs received single 5 mg dose of naloxone intravenously, the plasma concentration-time curves could be fitted to two-compartment open model, with 12.0 min of t1/2( , 143.4 min of t1/2( and 7.92 mg(min/L of AUC. The same eight dogs received 5 mg dose of the sublingual naloxone tablet after an interval of a week. The main pharmacokinetic parameters were: t1/2ka = 11.0 min, t1/2( = 15.4 min, t1/2( = 164.1 min, Tmax = 27.7 min, Cmax = 34.2 ng / ml, and AUC = 6.79 mg(min / L, respectively. The plasma concentration-time curves were fitted to the first order absorption two-compartment open model also. The mean absolute bioavailability of the sublingual naloxone tablet was 86.8 ( 10.9%. No statistically significant differences were found with t1/2(, t1/2(, ( and ( between the two routes of administration. These results indicated that the course of disposition for naloxone in dogs was similar for the two routes of administration, and the absolute bioavailability of the sublingual naloxone tablet was high. Thus satisfactory clinical effects could be expected.
基金supported by the National Basic Research Program of China(973 Program)2010CB530200(2010CB530206)the China-US Collaborative Program on Emerging and Re-emerging Infectious Disease(No.1U2GGH000018-01)
文摘Objective:To evaluate the Anaplasma phagocytophilum(A.phagocytophilum),Ehrlichia canis(E.canis,Dirofilaria immitis(D.immitis)(canine heartworm),Borrelia burgdorferi(B.burgdorferi)infections in countryside dogs from Yunnan,Hainan and Anhui provinces.Methods:Serum samples were collected from 26 dogs in Yunnan.Hainan and Anhui provinces.The samples were tested using a commercial ELISA rapid diagnostic assay kit(SNAP^(?)4Dx^(?);IDEXX Laboratories,Inc.U.S.A.).Meaiiwliile,indirect immunofluorescence assay(IFA)recommended by WHO was conducted to delect IgG to A.phagocytophilum.Two methods were analyzed and compared.Results:The number of serologically positive dogs for IgG to A.phagocytophilum was only 2which was from Hainan province and none of the 26 dogs responded positive for E.canu.D.immitis(canine heartworm,and B.burgdorferi by ELISA rapid diagnostic method.The number of serologically positive dogs for IgG to A.phagocytophilum was 13(50%)by IFA method.Data of the two methods were analyzed by statistical software and the difference was statistically significant(P=0.002).Conclusions:It can be concluded that IFA method was more sensitive than ELISA rapid diagnostic method.However,we need conduct further and intensive epidemiology survey on tick-born diseases pathogens including.4.phagocytophilum,E.canis,D.immitis(canine heartworm),and B.burgdorferi which have public health significance.
基金Supported by Directorate of Research,Guru Angad Dev Veterinary and Animal Sciences University,Ludhiana-141004,India.Grant No.-RKVYB-2(Ⅲ)c(d)DR-2,sanctioned on October,2010
文摘Objective:To evaluate clinical and hematological aspects of dogs naturally infected with Hepatozoon canis(H.canis)presented at the Small Animal Clinics of Guru Angad Dev Veterinary and Animal Sciences University,Ludhiana.Methods:Blood films of 34 naturally infected dogs were examined for haematological alterations and parasitaemia.Signalment and clinical signs were recorded from the animals.Clinical histories were filled oul during the consultation.Results:Of the 34 positive dogs by Giemsa stained peripheral blood films.88.23%presented parasilaemia by H.canis only,while 11.77%had the combination of H.canis,Babesia sp.and Ehrlichia sp.Young male dogs less than oue-year-old,of nondescript breed,were the most commonly affected.And 26.47%were presented with anorexia/inappetence as the only clinical symptom.Other clinical symptoms were mild to moderate fever,pale mucosae and lethargy;a few were also showing the signs of vomiting and diarrhoea.Haematological alterations showed mainly normochromic-normocytic anaemia,leukocytosis and neutrophilia.Conclusions:The findings of this study substantiate that H.canis caused clinical and haematological alterations of the varied intensity in dogs,even with low parasilaemia.should he taken into consideration.
基金supported by the National Natural Science Foundation of China(No.91231108)the Breakthrough Project of Strategic Priority Program of the Chinese Academy of Sciences(No.XDB13000000)+1 种基金the Key Research Program of the Chinese Academy of Sciencesthe Youth Innovation Promotion Association,Chinese Academy of Sciences(to GDW)
文摘Hypoxia represents one of the most extreme environmental conditions for both human beings and animals living at high al- titudes （Zhao et al., 2009）. Over the past few years, great attention has been focused on the genetic bases of adaption to high-altitude environments （Bigham et al., 2010; Simonson et al., 2010）. The domestic dog （Canisfamiliaris） is the first animal that developed an intimate relationship with human beings. Dogs migrated with human beings and have adapted to variety of ecological niches （Savolainen et al., 2002）. Our previous research revealed parallel evolution and convergent evolution in the adaptation of dogs and humans to the high-altitude environment of the Tibetan plateau （Wang et al., 2013, 2014）, suggesting that exploring the adaption of domestic dogs to high-altitude hypoxia is an interesting and important question.
基金financially supported by the National Key Research and Development Program of China (No. 2017YFD0500103)the National Natural Science Foundation of China (No. 31772747)+2 种基金the Science and Technology Development Project of Jilin Province (No. 20170623043TC)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, No. 2017TD-28)the Fundamental Research Funds for the Central Universities
文摘Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014;Ge et al. 2018).
基金Supported by grants from the National Natural Science Foundation of China:Studies on the Structure of Bioactive Substance from Spatholobus Suberectus Dunn and Its Mechanism of Hematopoietic Regulation Effect(No.30070890)Mechanism of Anti-oxidant Effect and the Activating-hematopoiesis Effect of Spatholobus Suberectus Dunn and Its Active Consititutents(No.81373781)
文摘OBJECTIVE:To investigate the radioprotective ef fect of tea polyphenols(TP 50)against radiation-in duced organ and tissue damage.METHODS:Beagle dogs were exposed to a single acute dose of whole-body y-radiation(3 Gy)and orally administered TP 50(80 or 240 mg·kg-1·d-1)for 28 consecutive days.A hemogram was obtained from experimental dogs every other day for 42 d.At the end of the experiment,enzyme activities of the antioxidants superoxide-dismutase and glutathione peroxidase,serum levels of inflammatory cytokines(tumor necrosis factor-a,interleukin-1β,and interleukin-6),colony-forming units of bone marrow hematopoietic progenitor cells,and organ coefficients were measured.RESULTS:Dogs exposed to γ-radiation alone exhibited typical hematopoietic syndrome.In contrast,irradiated dogs that received TP 50 exhibited an improved blood profile with reduced leucopenia,thrombocytopenia(platelet counts),and reticulocyte levels.TP 50 also significantly elevated levels of the endogenous antioxidant enzyme superoxide-dismutase,reduced the increased levels of serum cytokine in response to radiation-induced toxicity,and increased colony-forming units of bone marrow hematopoietic progenitor cells.In addition,TP 50 repaired radiation-induced organ damage.CONCLUSION:The current findings suggest that oral administration of TP 50 to beagle dogs effectively alleviated hematopoietic bone marrow damage induced by y-radiation.
基金National High Technology Research and Development Program of China(No.2007BAI14IB04)Major State Basic Research Development Program(No.2004CB518902)
文摘OBJECTIVE To compare the pharmacokinetics and pharmacodynamics of PEG30-rhG-CSF administered to beagle dogs at three different dosages with PEG20-rhG-CSF administered at one dosage, and to provide an experimental basis for clinical trials.METHODS Beagle dogs received single, subcutaneous doses of PEG30-rhG-CSF at 100, 200 and 400 μg/kg or PEG20-rhG-CSF at 200 μg/kg. PEG30-rhG-CSF and PEG20-rhG-CSF concentrations in serum were analyzed using an enzymeqinked immunosorbent assay （ELISA）. WBC, ANC and PLT counts of whole blood samples were measured using fully automated analytic instrumentation. Pharmacokinetic and pharmacodynamic parameters were calculated using DAS 2.0 statistical analysis software.METHODS Beagle dogs received single, subcutaneous doses of PEG30-rhG-CSF at 100, 200 and 400 μg/kg or PEG20-rhG-CSF at 200μg/kg. PEG30-rhG-CSF and PEG20-rhG-CSF concentrations in serum were analyzed using an enzyme-linked immunosorbent assay （ELISA）. WBC, ANC and PLT counts of whole blood samples were measured using fully automated analytic instrumentation. Pharmacokinetic and pharmacodynamic parameters were calculated using DAS 2.0 statistical analysis software. RESULTS The pharmacokinetic parameters of PEG30-rhG-CSF calculated from the serum concentration data determined by ELISA were as follows： the mean elimination half-life （t1/2ke） was 40.6 h （33.5-45.4 h）; the mean time to reach peak concentration （Tmax） was 19.2 h （11.7-24.0 h）; the drug clearance from the serum （CL） was decreased with increasing doses; the peak concentration （Cmax） and the area under the serum concentration-time curve （AUC） were increased with increasing doses. For PEG20-rhG- CSF, the half-life was shorter （12 h） and Tmax was achieved much earlier （10 h） relative to PEG30-rhG-CSF. The AUC of PEG30- rhG-CSF was much greater than that of PEG20-rhG-CSF, and the relative bioavailability with a subcutaneous injection was 158.7%. Administration of single doses of PEG30-rhG-CSF resulted in substantial increases in the absolute The time to reach ANC （ANCTmax） neutrophil count （ANC）. was 72 h. The maximum observed absolute neutrophil counts （ANCmax） and the area over the baseline effect curve （AOBEC） was increased with increasing doses. The effect-elimination half-life （t1/2E） ranged from 60 h to 80 h after subcutaneous administration. The PLT count was slightly elevated 8-12 h after s.c. injection, and declined after 24 h. CONCLUSION The mean elimination half-life of PEG30-rhG- CSF was longer than that of PEG20-rhG-CSF at the same dose, and the other main pharmacokinetic and pharmacodynamic parameters of PEG30-rhG-CSF, including C ANCmax, AUC and AOBEC were much greater than those following PEG20-rhG-CSF injection.
文摘Background： During sperm maturation, there is a reorganization of fatty acids from plasmatic membrane of the spermatozoa, which allows higher membrane integrity and acquisition of sperm motility. However, the fatty acid profile during sperm maturation remains unclear in dogs. Thus, the aim of this study was to identify the fatty acids from the epididymal spermatozoa and plasma during the sperm maturation, and observed changes in the motility and plasmatic membrane parameters. Twenty one adult dogs were used, subsequently to bilateral orchiectomy and epididymal storage, sperm samples were collected from the different segments of the epididymis. Samples were evaluated for conventional microscopy, computer-assisted motility analysis, sperm plasma membrane permeability and the fatty acid analysis（lipids were extracted, transmethylated and analyzed by chromatography）.Results： Caput and corpus sperm showed lower values for the motility variables evaluated and plasmatic membrane integrity, indicating different levels of the fatty acids organization. Saturated, monounsaturated and polyunsaturated fatty acids were in higher concentrations in the spermatozoa from epididymis cauda. Highlighting the presence of caprylic, stearic and docosahexaenoic acids.Conclusions： These findings demonstrate the influence of the fatty acid profile during sperm maturation, assigning physical and chemical changes in sperm cells, essential for fertilization.
基金supported by the Research Foundation of the State of So Paulo (FAPESP/Brazil)National Council of Technological and Scientific Development (CNPq/Brazil)
文摘Didanosine is an effective antiviral drug in untreated and antiretroviral therapy-experienced patients with Human Immunodeficiency Virus (HIV). An automated system using on-line solid extraction and High Performance Liquid Chromatography (HPLC) with ultraviolet (UV) detection was developed and validated for pharmacokinetic analysis of didanosine in dog plasma. Modifications were introduced on a previous methodology for simultaneous analysis of antiretroviral drugs in human plasma. Extraction was carried out on C18 cartridges, with high extraction yield as stationary phase, whereas mobile phase consisted of a mixture of 0.02 M potassium phosphate buffer, acetonitrile (KH2PO4: acetonitrile: 96:4, v/v) and 0.5% (w/v) of heptane sulphonic acid. The pH was adjusted to 6.5 with triethylamine. All samples and standard solutions were chromatographed at 28 1C. For an isocratic run, the fiux was 1.0 mL/min, detection was at 250 nm and injected volume was 20 mL. The method was selective and linear for concentrations between 50 and 5000 ng/mL. Drug stability data ranged from 96% to 98%, and limit of quantification was 25 ng/mL. Extraction yield was up to 95%. Drug stability in dog plasma was kept frozen at 20 1C for one month after three freeze–thaw cycles, and for 24 h after processing in the auto sampler. Assay was successfully applied to measure didanosine concentrations in plasma dogs.
文摘The goal of this study was to evaluate the influence of natural variation in the regenerative status of dog tissues on the signs of hormesis, which are evident after total body exposure to low daily doses of external gamma radiation throughout the lifespan. Ninety beagle dogs of both sexes were irradiated with cobalt 60 at 0.003 Gy/day commencing 1 year after birth to death. Control (n = 169) and irradiated animals underwent whole-life clinical observation and autopsy, and were then retrospectively divided into two subgroups with (W) or without benign tumors or tumors of unknown nature (WO) that were clinically recorded on single days throughout the lifespan. Radiation hormesis was only detected in subgroup WO, which had life span (LS) of 10.7 years in the absence of radiation. The radiogenic prolongation of life to 11.8 years in the WO subgroup (p 【0.05) was similar to that in the W control and irradiated W subgroups (11.8 and 11.5 years, respectively). The number of solid malignancies found upon autopsy of the control WO subgroup was less (39.5%) than that evident in the control W subgroup (60%). Compared to the irradiated W subgroup, irradiation of the WO subgroup was accompanied by a slight increase (1.14-fold) in the number of solid malignancies evident at autopsy and in the clinical signs of tissue atrophy and body weight loss (2.4-fold and 2.4-fold, respectively), but was accompanied by strong reductions in the extent of anemia and hemoblastoses (】10-fold for both). The data exclude the notion that radiation is associated with healing, but suggest that certain pathologies (e.g., hemoblastoses) may be substituted with other less dangerous somatic diseases in weaker animals only.
基金the Experimental Animal Research Project of Hubei Province(Grant No.2023CFA005).
文摘Feline panleukopenia virus(FPV)is a single-stranded DNA virus that can infect cats and cause feline panleukopenia,which is a highly contagious and fatal disease in felines.The sequence of FPV is highly variable,and mutations in the amino acids of its capsid protein play crucial roles in altering viral virulence,immunogenicity,host selection,and other abilities.In this study,the epidemiology of FPV was studied using 746 gastrointestinal swab samples derived from cats that presented gastrointestinal symptoms specifcally,diarrhea or vomiting during the period spanning from 2018 to 2022.The overall prevalence of FPV-positive patients among these samples was determined to be 45.4%.Capsid(virion)protein 2(VP2)gene of each FPV-positive sample was sequenced and amplifed,yielding 65 VP2 sequences.Among them,six VP2 gene sequences were detected in the majority of the samples test positive for FPV,and these positive samples originated from a diverse range of geographical locations.These isolates were named FPV-6,FPV-10,FPV-15,FPV-251,FPV-271 and FPV-S2.Additionally,the substitution of Ala300Pro(A300P)in VP2 was detected for the frst time in feline-derived FPV(FPV-251).FPV-251 isolate,with this substitution in VP2 protein,exhibited stable proliferative capacity in Madin-Darby canine kidney(MDCK)cells and A72 cells.FPV-271 was selected as the FPV control isolate due to its single amino acid diference from VP2 protein of FPV-251 at position 300(FPV-271 has alanine,while FPV-251 has proline).After oral infection,both FPV-251 and FPV-271 isolates caused feline panleukopenia,which is characterized by clinical signs of enterocolitis.However,FPV-251 can infect dogs through the oral route and cause gastrointestinal(GI)symptoms with lesions in the intestine and mesenteric lymph nodes(MLNs)of infected dogs.This is the frst report on the presence of an A300P substitution in VP2 protein of feline-derived FPV.Additionally,FPV isolate with a substitution of A300P at VP2 protein demonstrated efcient replication capabilities in canine cell lines and the ability to infect dogs.
