[Objective] This study aimed to investigate the distribution law of different goblet cells in the intestinal tracts of African ostrich chicks. [Method] Alcian blue/pe- riodic acid-schiff reaction (AB/PAS) was adopte...[Objective] This study aimed to investigate the distribution law of different goblet cells in the intestinal tracts of African ostrich chicks. [Method] Alcian blue/pe- riodic acid-schiff reaction (AB/PAS) was adopted to observe and analyze the types and distribution of goblet cells in the intestinal tracts of ostrich chicks. Acid mu- copolysaccharide could be stained blue with alcian blue (AB), and neutral mu- copolysaccharide could be stained red with periodic acid-schiff reagent (PAS). [Result] According to AB/PAS results, goblet cells in the intestinal tracts were divided in- to four types: TypeⅠ was pure red, with AB negative result and PAS positive result containing neutral mucoitin; type Ⅱ was pure blue, with AB positive result and PAS negative result containing acidic mucoitin; type Ⅲ was purple reddish, with PAS posi- tive result greater than AB; typeⅣ was purple blue, with AB positive result greater than PAS. Large quantities of goblet cells were found in the intestinal tracts of os- trich chicks, mostly type III and IV.The quantities of goblet cells were decreased gradually in the duodenum, jejunum and ileum, while the quantities were increased in the cecum, colon and rectum. The goblet cells in the large intestine are more than that in the small intestine. The most quantities of goblet cells were contained in rectum. [Conclusion] These results indicate that the distribution of goblet cells is closely related with the structure and function of intestinal tracts. The mucus secret- ed by the goblet Cells plays a series of important roles in the digestion and mucosal immunization.展开更多
[Objective] This study aimed to investigate the differences in morphological structure of tibias between sick and normal ostrich chicks. [Method] Normal and sick ostrich chicks aged 90 days were used in this research ...[Objective] This study aimed to investigate the differences in morphological structure of tibias between sick and normal ostrich chicks. [Method] Normal and sick ostrich chicks aged 90 days were used in this research for bone mineral density determination, bone demineralization paraffin section preparation (HE staining), bone abrasive disc preparation and scanning electron microscopy (SEM) observation, to analyze the differences in microstructure and ultrastructure of tibias between sick ostrich chicks and normal ones. [Result] Bone mineral density of ostrich chicks suffering from leg disease was much lower than that of the normal ones. Compared with normal tibias, less trabeculae were observed in sick tibias, which were attenuated and began to disappear. In addition, trabeculae micro-fracture could be observed under scanning electron microscope; resorption pits on bone slices formed by osteoclast could be observed under scanning electronic microscope. [Conclusion] These results indicate that the sick tibias all have lower bone density and trabeculae microfracture phenomenon in tibias with different diseases, which might be resulted from osteoporosis.展开更多
AIM: To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS: A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea...AIM: To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS: A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea. The microstructure of the acellular corneal matrix was observed by transmission electron microscopy (TEM) and hematoxylin and eosin (H&E) staining. The mechanical properties were detected by a rheometer and a tension machine. The acellular corneal matrix was also transplanted into a rabbit cornea and cytokeratin 3 was used to check the immune phenotype, RESULTS: The microstructure and mechanical properties of the ostrich cornea were well preserved after the decellularization process, in vitro, the methyl thiazolyl tetrazoUum results revealed that extracts of the acellular ostrich corneas (AOCs) had no inhibitory effects on the proliferation of the corneal epithelial or endothelial cells or on the keratocytes, The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea (APC) transplantation, The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer, CONCLUSION: We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft.展开更多
Struthio linxiaensis is the oldest fossil ostrich from Asia till today. This paper analyzes the microstructure of the eggshell of Struthio linxiaensis. The SEM and light microscopic results show that a pathological st...Struthio linxiaensis is the oldest fossil ostrich from Asia till today. This paper analyzes the microstructure of the eggshell of Struthio linxiaensis. The SEM and light microscopic results show that a pathological structure occurred associated with the formation of pore canal. The feature of this structure is that crystals of the columnar layer are around the lower part of the pore canal, and formed a broad structure. This structure unit contracts upwards more severely than the canal and looks like a "garlic", which was observed in aumiotes eggshells for the first time. Many evidences indicate that this structure was deposited with the columns simultaneously. The radial section view suggests that the "garlic structure" is not a result of antiperistaltic waves in the avian oviduct. The most possible process of the "garlic structure" formation is the column units around the pore canals with imperfect acidifying when calcified, or have some correlations with the changes in the protein profiles of the organic matrix in the calcareous eggshell.展开更多
In chickens, infectious bronchitis (IB) is a major respiratory disease. The respiratory system is the primary multiplication site of IB virus (IBV), a coronavirus, after which the virus is distributed to other organs....In chickens, infectious bronchitis (IB) is a major respiratory disease. The respiratory system is the primary multiplication site of IB virus (IBV), a coronavirus, after which the virus is distributed to other organs. Poultry farms sustain considerable economic damage due to IB outbreaks in flocks, since IB causes a severe reduction in weight gain in chicks. In the present study, we produced the ostrich IgY against IBV by immunizing female ostriches with the IB viral antigens. The resultant purified IgY showed a strong neutralizing activity against IBV infection of cultured primary chick kidney cells. The infectivity of IBV was markedly inhibited in the trachea of chicks when ostrich IgY was injected intra-muscularly into newly hatched chicks prior to viral inhalation challenge at two weeks of age. Furthermore, the infection was strongly blocked in the tracheae when IgY was injected into chicks at one day and one week of age, with viral inhalation performed at three weeks of age. These findings suggest that the injection of ostrich IgY can help protect young chicks from IBV infections. In south Asian and African countries, broiler chicks are sent to poultry market around 30 days of age, so it is important to prevent IB outbreaks in very young flocks. We strongly believe that ostrich IgY will be a powerful weapon against IB infection in poultry farms on a wide scale and also hope that these findings will aid in the development of antibody vaccines for new type corona viruses, SARS-CoV and MERS-CoV.展开更多
Antibodies are immunoglobulins produced by B cells when antigens such as allergens or pathogens invade an animal’s body. The antibodies remove and inactivate antigens. Antibodies are distributed in internal body and ...Antibodies are immunoglobulins produced by B cells when antigens such as allergens or pathogens invade an animal’s body. The antibodies remove and inactivate antigens. Antibodies are distributed in internal body and mucosal membrane to protect living animals, but they are excellent proteins that can exert their functions, “antigen-antibody reactions,” even when removed from the body. For that reason, antibodies are being put to practical use in diagnostic kits for conditions such as pregnancy and influenza infection, and as anticancer drugs targeting specific tumor markers. The result has been an increasing use of antibodies for research, diagnosis, and therapeutic purposes. Unfortunately, antibodies from experimental mammals such as mice, rats, and rabbits, are not suited to industrial use because of their high production cost. Moreover, handling of these antibodies is difficult due to their vulnerability to heat, acids and alkalis. Accordingly, there is no adaptability to mass production. Recently, we developed a convenient method for the low-cost, mass-production of antibodies using egg-laying hen ostriches. The ostrich egg is an excellent source of antibodies for industrial purposes. The present report shows that the ostrich antibodies have therapeutic effects in ailments such as atopic dermatitis, acne, pyoderma, and pollen allergies. We have successfully produced and purified ostrich immunoglobulin yolk (IgY) against pollen allergens (Cryj1, Cryj2, Chao1, Chao2) and found that allergic reactions were alleviated in skin patch tests of allergic patients by using the ostrich IgY. In addition, we produced ostrich IgY against the homogenates of Staphylococcus aureus and Propionibacterium acnes, and applied to dermal lesions of atopic dermatitis and acne patients, and then observed the therapeutic effects on the dermatitis of volunteer subjects. Antibody against S. aureus also had the therapeutic effect on canine pyoderma caused by MRSA. A particular advantage in using ostrich antibodies is the fact that they inactivate and neutralize a specific antigen, without damaging the indigenous microflora of the dermal surface. In this review article and case repot, we wish to suggest that ostrich antibodies can contribute to the treatment of cutaneous disorders as an alternative to treatment with steroids or antibiotics.展开更多
The hormone dihydro testosterone (DHT) and the catalyst 5α-reductase are key contributors to hair loss due to androgenetic alopecia (AGA). Also, dermal bacteria and their toxins have been implicated in hair loss. A p...The hormone dihydro testosterone (DHT) and the catalyst 5α-reductase are key contributors to hair loss due to androgenetic alopecia (AGA). Also, dermal bacteria and their toxins have been implicated in hair loss. A preliminary study by the authors with six male volunteer subjects showed that ostrich antibodies against above causative substances were quite effective in promoting hair regrowth. The present study included 13 men and 4 women, with ages ranging from 39 to 78. Pre- and post-treatment hair counts were also incorporated into the study procedure. In all instances but one, the subjects had a hair-growth effect about 3 months after the antibody was applied to the scalp, and the study participants with hair growth were pleased with the results and with the ease of use of the antibody solution.展开更多
The hormone dihydrotestosterone (DHT) and the catalyst 5α-reductase play very important roles in the hair loss due to androgenetic alopecia (AGA). Recently, some chemicals against these hormones have been commerciali...The hormone dihydrotestosterone (DHT) and the catalyst 5α-reductase play very important roles in the hair loss due to androgenetic alopecia (AGA). Recently, some chemicals against these hormones have been commercialized as therapeutics for AGA. In the present study, we have attempted to find out the potential effects of antibodies on AGA therapeutics as an inhibitor of androgenic hormones. The immune system of the ostrich is believed to be the most versatile and powerful of any animal on the planet, and antibodies derived from the ostrich egg yolk are now being developed for a wide range of diseases and ailments. Ostrich antibodies against DHT and 5α-reductase have been produced and combined with antibodies against harmful skin bacteria to restore normal hair growth in AGA cases. Preliminary testing with six volunteer subjects showed that ostrich antibodies were clearly quite effective in hair regrowth.展开更多
In this research, the state of the gastric secretion in 38 days old ostrich embryos and chicks of different age was investigated by determining the pH level in the stomach as well as the histological structure of the ...In this research, the state of the gastric secretion in 38 days old ostrich embryos and chicks of different age was investigated by determining the pH level in the stomach as well as the histological structure of the deep proventricular glands (gll. proventriculares profundi). In both parts of the stomach, on the 38th day of embryonic development pH parameters were higher than in chicks after hatching. The proventricular deep gland lobules and secretory epithelium on the 38th day of embryonic development and on the day of hatching were comparatively poorly developed. The most rapid increase of the proportion of the secretory epithelium of the proventricular deep glands was observed just before hatching and during the first week after hatching, but having reached two weeks of age it did not increase any more. The obtained results allow making a conclusion that already on the day of hatching an intensive gastric juice secretion occurs in the proventricular deep glands regardless of the stage of their histological development. The gastric intraluminal pH parameters indicate that the gastric secretion increases with chicks advancing in age, however on the day of hatching this important gastric function is biologically rather complete.展开更多
The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed t...The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed to bush meat activities, predation on their eggs illegal consumption by humans, habitat destruction and forage competition with other large wildlife species. Climate change is also emerging to be another major threat due to interference with food availability which in turn interferes with the breeding rhythm. Thus, this study examined the population status, trend and distribution of the Maasai ostrich in the Southern Kenya and Northern Tanzania borderland after the 2007 to 2009 drought. The results showed that the species was found across the entire borderland but the Amboseli region had the highest number and density of Maasai ostrich (726.00 ± 100.9;0.08 ± 0.01 ostriches per km<sup>2</sup>), followed by Lake Natron area (330.8 ± 69.8;0.05 ± 0.01 ostriches per km<sup>2</sup>) and the least was in West Kilimanjaro (85.5 ± 18.0;0.03 ± 0.01 ostriches per km<sup>2</sup>). Drought caused a decline in the population of the Maasai ostrich but the Amboseli area experienced the highest decline in density (?13.44 ± 12.61) compared to other borderland sectors. However, the populations increased in most sectors after the drought, and wet season numbers and densities were higher than the dry season. The highest positive increase in number and density was in Lake Natron area (+85.65 ± 91.06) followed by West Kilimanjaro (+68.39 ± 59.54), and the least was in the Magadi area (+22.26 ± 32.05). There is a need to enhance conservation of avian species like the Maasai ostrich other than just focusing on the charismatic species such as the African elephant and black rhino. We therefore recommend joint collaboration in monitoring all large wildlife populations across the Kenya-Tanzania borderland with a view of understanding their status, trend and best management actions that can enhance their conservation.展开更多
Ostrich eggshell beads and fragments collected from SDG site reflect primordial art and a kind of symbolic behavior of modern humans. Based on stratigraphic data and OSL dating, these ostrich eggshell beads are probab...Ostrich eggshell beads and fragments collected from SDG site reflect primordial art and a kind of symbolic behavior of modern humans. Based on stratigraphic data and OSL dating, these ostrich eggshell beads are probably in Early Holocene (< 10 ka BP). Two different prehistoric manufacturing pathways are usually used in the manufacture of ostrich eggshell beads in Upper Paleolithic. According to statistic analysis of the characteristics of ostrich eggshell beads, Pathway 1 is identified from these collections. In pathway 1, blanks are drilled prior to being trimmed to rough discs. They exhibit great potential for the study of the origin of primordial art and the development of ancient cultures and provide important data for studying behavioral options adopted by hominids in SDG area. In addition, they bear important implications for the origin of modern humans in East Asia.展开更多
基金Supported by National Natural Science Foundation of China (30972152)Specialized Research Fund for the Doctoral Program of Higher Education of China (200805040023)~~
文摘[Objective] This study aimed to investigate the distribution law of different goblet cells in the intestinal tracts of African ostrich chicks. [Method] Alcian blue/pe- riodic acid-schiff reaction (AB/PAS) was adopted to observe and analyze the types and distribution of goblet cells in the intestinal tracts of ostrich chicks. Acid mu- copolysaccharide could be stained blue with alcian blue (AB), and neutral mu- copolysaccharide could be stained red with periodic acid-schiff reagent (PAS). [Result] According to AB/PAS results, goblet cells in the intestinal tracts were divided in- to four types: TypeⅠ was pure red, with AB negative result and PAS positive result containing neutral mucoitin; type Ⅱ was pure blue, with AB positive result and PAS negative result containing acidic mucoitin; type Ⅲ was purple reddish, with PAS posi- tive result greater than AB; typeⅣ was purple blue, with AB positive result greater than PAS. Large quantities of goblet cells were found in the intestinal tracts of os- trich chicks, mostly type III and IV.The quantities of goblet cells were decreased gradually in the duodenum, jejunum and ileum, while the quantities were increased in the cecum, colon and rectum. The goblet cells in the large intestine are more than that in the small intestine. The most quantities of goblet cells were contained in rectum. [Conclusion] These results indicate that the distribution of goblet cells is closely related with the structure and function of intestinal tracts. The mucus secret- ed by the goblet Cells plays a series of important roles in the digestion and mucosal immunization.
基金Supported by Specialized Research Fund for The Doctoral Program of Huazhong Agricultural University(200805040023)Natural Science Foundation of China(NSFC)(30471249,30972152)~~
文摘[Objective] This study aimed to investigate the differences in morphological structure of tibias between sick and normal ostrich chicks. [Method] Normal and sick ostrich chicks aged 90 days were used in this research for bone mineral density determination, bone demineralization paraffin section preparation (HE staining), bone abrasive disc preparation and scanning electron microscopy (SEM) observation, to analyze the differences in microstructure and ultrastructure of tibias between sick ostrich chicks and normal ones. [Result] Bone mineral density of ostrich chicks suffering from leg disease was much lower than that of the normal ones. Compared with normal tibias, less trabeculae were observed in sick tibias, which were attenuated and began to disappear. In addition, trabeculae micro-fracture could be observed under scanning electron microscope; resorption pits on bone slices formed by osteoclast could be observed under scanning electronic microscope. [Conclusion] These results indicate that the sick tibias all have lower bone density and trabeculae microfracture phenomenon in tibias with different diseases, which might be resulted from osteoporosis.
基金Supported by National Natural Science Foundation of China(No.31200724)Key Innovation Project of Shaanxi Science and Technology Plan(No. 2012KTCQ03-11)+1 种基金Shenzhen Peacock Plan(No. KQCX20130628155525051)Projects of Basic Research of Shenzhen(No.JCYJ20120614193611639,No.JCYJ 20140509172959988)
文摘AIM: To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS: A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea. The microstructure of the acellular corneal matrix was observed by transmission electron microscopy (TEM) and hematoxylin and eosin (H&E) staining. The mechanical properties were detected by a rheometer and a tension machine. The acellular corneal matrix was also transplanted into a rabbit cornea and cytokeratin 3 was used to check the immune phenotype, RESULTS: The microstructure and mechanical properties of the ostrich cornea were well preserved after the decellularization process, in vitro, the methyl thiazolyl tetrazoUum results revealed that extracts of the acellular ostrich corneas (AOCs) had no inhibitory effects on the proliferation of the corneal epithelial or endothelial cells or on the keratocytes, The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea (APC) transplantation, The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer, CONCLUSION: We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft.
文摘Struthio linxiaensis is the oldest fossil ostrich from Asia till today. This paper analyzes the microstructure of the eggshell of Struthio linxiaensis. The SEM and light microscopic results show that a pathological structure occurred associated with the formation of pore canal. The feature of this structure is that crystals of the columnar layer are around the lower part of the pore canal, and formed a broad structure. This structure unit contracts upwards more severely than the canal and looks like a "garlic", which was observed in aumiotes eggshells for the first time. Many evidences indicate that this structure was deposited with the columns simultaneously. The radial section view suggests that the "garlic structure" is not a result of antiperistaltic waves in the avian oviduct. The most possible process of the "garlic structure" formation is the column units around the pore canals with imperfect acidifying when calcified, or have some correlations with the changes in the protein profiles of the organic matrix in the calcareous eggshell.
文摘In chickens, infectious bronchitis (IB) is a major respiratory disease. The respiratory system is the primary multiplication site of IB virus (IBV), a coronavirus, after which the virus is distributed to other organs. Poultry farms sustain considerable economic damage due to IB outbreaks in flocks, since IB causes a severe reduction in weight gain in chicks. In the present study, we produced the ostrich IgY against IBV by immunizing female ostriches with the IB viral antigens. The resultant purified IgY showed a strong neutralizing activity against IBV infection of cultured primary chick kidney cells. The infectivity of IBV was markedly inhibited in the trachea of chicks when ostrich IgY was injected intra-muscularly into newly hatched chicks prior to viral inhalation challenge at two weeks of age. Furthermore, the infection was strongly blocked in the tracheae when IgY was injected into chicks at one day and one week of age, with viral inhalation performed at three weeks of age. These findings suggest that the injection of ostrich IgY can help protect young chicks from IBV infections. In south Asian and African countries, broiler chicks are sent to poultry market around 30 days of age, so it is important to prevent IB outbreaks in very young flocks. We strongly believe that ostrich IgY will be a powerful weapon against IB infection in poultry farms on a wide scale and also hope that these findings will aid in the development of antibody vaccines for new type corona viruses, SARS-CoV and MERS-CoV.
文摘Antibodies are immunoglobulins produced by B cells when antigens such as allergens or pathogens invade an animal’s body. The antibodies remove and inactivate antigens. Antibodies are distributed in internal body and mucosal membrane to protect living animals, but they are excellent proteins that can exert their functions, “antigen-antibody reactions,” even when removed from the body. For that reason, antibodies are being put to practical use in diagnostic kits for conditions such as pregnancy and influenza infection, and as anticancer drugs targeting specific tumor markers. The result has been an increasing use of antibodies for research, diagnosis, and therapeutic purposes. Unfortunately, antibodies from experimental mammals such as mice, rats, and rabbits, are not suited to industrial use because of their high production cost. Moreover, handling of these antibodies is difficult due to their vulnerability to heat, acids and alkalis. Accordingly, there is no adaptability to mass production. Recently, we developed a convenient method for the low-cost, mass-production of antibodies using egg-laying hen ostriches. The ostrich egg is an excellent source of antibodies for industrial purposes. The present report shows that the ostrich antibodies have therapeutic effects in ailments such as atopic dermatitis, acne, pyoderma, and pollen allergies. We have successfully produced and purified ostrich immunoglobulin yolk (IgY) against pollen allergens (Cryj1, Cryj2, Chao1, Chao2) and found that allergic reactions were alleviated in skin patch tests of allergic patients by using the ostrich IgY. In addition, we produced ostrich IgY against the homogenates of Staphylococcus aureus and Propionibacterium acnes, and applied to dermal lesions of atopic dermatitis and acne patients, and then observed the therapeutic effects on the dermatitis of volunteer subjects. Antibody against S. aureus also had the therapeutic effect on canine pyoderma caused by MRSA. A particular advantage in using ostrich antibodies is the fact that they inactivate and neutralize a specific antigen, without damaging the indigenous microflora of the dermal surface. In this review article and case repot, we wish to suggest that ostrich antibodies can contribute to the treatment of cutaneous disorders as an alternative to treatment with steroids or antibiotics.
文摘The hormone dihydro testosterone (DHT) and the catalyst 5α-reductase are key contributors to hair loss due to androgenetic alopecia (AGA). Also, dermal bacteria and their toxins have been implicated in hair loss. A preliminary study by the authors with six male volunteer subjects showed that ostrich antibodies against above causative substances were quite effective in promoting hair regrowth. The present study included 13 men and 4 women, with ages ranging from 39 to 78. Pre- and post-treatment hair counts were also incorporated into the study procedure. In all instances but one, the subjects had a hair-growth effect about 3 months after the antibody was applied to the scalp, and the study participants with hair growth were pleased with the results and with the ease of use of the antibody solution.
文摘The hormone dihydrotestosterone (DHT) and the catalyst 5α-reductase play very important roles in the hair loss due to androgenetic alopecia (AGA). Recently, some chemicals against these hormones have been commercialized as therapeutics for AGA. In the present study, we have attempted to find out the potential effects of antibodies on AGA therapeutics as an inhibitor of androgenic hormones. The immune system of the ostrich is believed to be the most versatile and powerful of any animal on the planet, and antibodies derived from the ostrich egg yolk are now being developed for a wide range of diseases and ailments. Ostrich antibodies against DHT and 5α-reductase have been produced and combined with antibodies against harmful skin bacteria to restore normal hair growth in AGA cases. Preliminary testing with six volunteer subjects showed that ostrich antibodies were clearly quite effective in hair regrowth.
文摘In this research, the state of the gastric secretion in 38 days old ostrich embryos and chicks of different age was investigated by determining the pH level in the stomach as well as the histological structure of the deep proventricular glands (gll. proventriculares profundi). In both parts of the stomach, on the 38th day of embryonic development pH parameters were higher than in chicks after hatching. The proventricular deep gland lobules and secretory epithelium on the 38th day of embryonic development and on the day of hatching were comparatively poorly developed. The most rapid increase of the proportion of the secretory epithelium of the proventricular deep glands was observed just before hatching and during the first week after hatching, but having reached two weeks of age it did not increase any more. The obtained results allow making a conclusion that already on the day of hatching an intensive gastric juice secretion occurs in the proventricular deep glands regardless of the stage of their histological development. The gastric intraluminal pH parameters indicate that the gastric secretion increases with chicks advancing in age, however on the day of hatching this important gastric function is biologically rather complete.
文摘The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed to bush meat activities, predation on their eggs illegal consumption by humans, habitat destruction and forage competition with other large wildlife species. Climate change is also emerging to be another major threat due to interference with food availability which in turn interferes with the breeding rhythm. Thus, this study examined the population status, trend and distribution of the Maasai ostrich in the Southern Kenya and Northern Tanzania borderland after the 2007 to 2009 drought. The results showed that the species was found across the entire borderland but the Amboseli region had the highest number and density of Maasai ostrich (726.00 ± 100.9;0.08 ± 0.01 ostriches per km<sup>2</sup>), followed by Lake Natron area (330.8 ± 69.8;0.05 ± 0.01 ostriches per km<sup>2</sup>) and the least was in West Kilimanjaro (85.5 ± 18.0;0.03 ± 0.01 ostriches per km<sup>2</sup>). Drought caused a decline in the population of the Maasai ostrich but the Amboseli area experienced the highest decline in density (?13.44 ± 12.61) compared to other borderland sectors. However, the populations increased in most sectors after the drought, and wet season numbers and densities were higher than the dry season. The highest positive increase in number and density was in Lake Natron area (+85.65 ± 91.06) followed by West Kilimanjaro (+68.39 ± 59.54), and the least was in the Magadi area (+22.26 ± 32.05). There is a need to enhance conservation of avian species like the Maasai ostrich other than just focusing on the charismatic species such as the African elephant and black rhino. We therefore recommend joint collaboration in monitoring all large wildlife populations across the Kenya-Tanzania borderland with a view of understanding their status, trend and best management actions that can enhance their conservation.
基金Supported by the National Basic Research Program of China (Grant No. 2006CB 806400)Specific Basic Research Program of Ministry of Sciences and Technol-ogy of China (Grant No. 2007FY110200)+1 种基金National Natural Science Foundation of China (Grant No. J0630965)Knowledge Innovation Project of the Chinese Academy of Sciences
文摘Ostrich eggshell beads and fragments collected from SDG site reflect primordial art and a kind of symbolic behavior of modern humans. Based on stratigraphic data and OSL dating, these ostrich eggshell beads are probably in Early Holocene (< 10 ka BP). Two different prehistoric manufacturing pathways are usually used in the manufacture of ostrich eggshell beads in Upper Paleolithic. According to statistic analysis of the characteristics of ostrich eggshell beads, Pathway 1 is identified from these collections. In pathway 1, blanks are drilled prior to being trimmed to rough discs. They exhibit great potential for the study of the origin of primordial art and the development of ancient cultures and provide important data for studying behavioral options adopted by hominids in SDG area. In addition, they bear important implications for the origin of modern humans in East Asia.