Paris polyphylla Smith is an important medicinal plant that is considered vulnerable in many parts of the world. The species exhibits poor adaptability to changed environment and susceptible to climatic conditions for...Paris polyphylla Smith is an important medicinal plant that is considered vulnerable in many parts of the world. The species exhibits poor adaptability to changed environment and susceptible to climatic conditions for reproductive vigor. During the present study the species was studied in four different natural niches as well as synthetic habitats to check the adaptability to artificial conditions, its morphological and physiological characters and its interaction in its community so that conservation strategies could be worked out. The present study indicates that P. polyphylla exhibits healthy growth as well as reproduction in undisturbed area with canopy covers over 80%. The plant grows in well-drained rich humus soil and grows well with certain key associated species such as Quercus species, Taxus baccata, Aconitum species, Eupatorium adenophorum, Smilax species etc. Many plants were non-flowering and more than 60% were found non-flowering in its habitat during its flowering season in any particular year. There are clear morphological changes as the flowers stages from pre-fertilization to post-fertilization. Arrangement of anthers in two whorls shows a distinct and unique floral display. Light is an important factor during seed setting and less than 50% shade lowers the seed productivity very significantly. Predators such as slugs and snails are found on the plant. Urgent conservation and new innovative ways are necessary to propagate this economically important plant to ensure its continuity.展开更多
Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we...Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we explored the main drivers of reproductive output in N.atrata.Results showed that prey abundance and food intake were crucial variables contributing to reproductive output.Multiple linear regression models showed that neonates had high sensitivity(R2=55.29%)to extreme changes in climate,which was strongly related to slug and snail abundance variability and microhabitat quality.Reproductive cycles were markedly different between the sexes,being continuous in males and cyclical in females.Despite this variation,reproductive cycles at the population level were seasonal semi-synchronous.Constant recruitment of neonates all year,multiple clutches,high mating frequency,and continuous sperm production characterized the reproductive phenology of N.atrata.In addition,a significant number of previtellogenic females presented oviductal sperm as well as uterine scars,suggesting a high precocity in the species.The main drivers of reproductive output also differed between the sexes.In females,clutch size and secondary follicle variability were highly related to stomach bolus volume,fat body area,and body mass.In males,height of piles of palm leaves and body mass,rather than intrinsic reproductive traits,were the main drivers of sperm production.Nevertheless,in both cases,the relationship between body mass,prey abundance,and food intake suggests that N.atrata follows the income breeding strategy to compensate for reproductive costs and to maximize fitness.展开更多
To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved a...To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved access to information on various Sexual Reproductive Health topics through Short Messaging Service (SMS) messages. Over the years, the platform has accumulated millions of incoming and outgoing messages, which need to be categorized into key thematic areas for better tracking of sexual reproductive health knowledge gaps among young people. The current manual categorization process of these text messages is inefficient and time-consuming and this study aims to automate the process for improved analysis using text-mining techniques. Firstly, the study investigates the current text message categorization process and identifies a list of categories adopted by counselors over time which are then used to build and train a categorization model. Secondly, the study presents a proof of concept tool that automates the categorization of U-report messages into key thematic areas using the developed categorization model. Finally, it compares the performance and effectiveness of the developed proof of concept tool against the manual system. The study used a dataset comprising 206,625 text messages. The current process would take roughly 2.82 years to categorise this dataset whereas the trained SVM model would require only 6.4 minutes while achieving an accuracy of 70.4% demonstrating that the automated method is significantly faster, more scalable, and consistent when compared to the current manual categorization. These advantages make the SVM model a more efficient and effective tool for categorizing large unstructured text datasets. These results and the proof-of-concept tool developed demonstrate the potential for enhancing the efficiency and accuracy of message categorization on the Zambia U-report platform and other similar text messages-based platforms.展开更多
The lack of validated tools to predict how long sow farms will remain PRRS virus-free following successful elimination of the virus has deterred veterinarians and producers from attempting to eliminate the PRRS virus ...The lack of validated tools to predict how long sow farms will remain PRRS virus-free following successful elimination of the virus has deterred veterinarians and producers from attempting to eliminate the PRRS virus from sow farms. The aim of this study was to use the database of PRRS Risk Assessments for the Breeding Herd in PADRAP to develop and validate an objective risk scoring system for predicting the likelihood of virus introduction in PRRS virus-free sow farms in the US. To overcome the challenges of dealing with a large number of variables, group lasso for logistic regression (GLLR) was applied to a retrospective dataset of PRRS Risk Assessment for the Breeding Herd surveys completed for 704 farms to develop the risk scoring system. The validity of the GLLR risk scoring system was then evaluated by testing its predictive ability on a dataset from a long-term prospective study of 196 sow farms to assess risk factors associated with how long PRRS virus-free sow farms remained PRRS virus-free. Receiver operator characteristic(ROC) curves were estimated to compare the performance of the GLLR risk scoring system to the risk scoring system based on expert opinion (EO), currently used in the PRRS Risk Assessment for the Breeding Herd, for predicting whether herds remained PRRS virus-free for 130 weeks. The GLLR risk scoring system (AUC, 0.76;95% CI, 0.67 - 0.84) performed significantly better than the EO risk scoring system (AUC, 0.36;95% CI, 0.27 - 0.46) for predicting whether to sow farms in the prospective study survived for 130 weeks (p 0.001). Dividing farms into 3 risk groups (low, medium and high) using a low and high cutoff values for the GLLR risk score was informative as the differences in the KM survival curves for the 3 groups were both clinically meaningful and statistically significant. The GLLR risk scoring system used in conjunction with the PRRS Risk Assessment for the Breeding Herd survey delivered through PADRAP appears to have the potential to help veterinarians predict the likelihood of virus introduction in PRRS virus-free sow farms in the US.展开更多
Intelligent equipment is a kind of device that is characterized by intelligent sensor interconnections, big data processing, new types of displays, human-machine interaction and so on for the new generation of informa...Intelligent equipment is a kind of device that is characterized by intelligent sensor interconnections, big data processing, new types of displays, human-machine interaction and so on for the new generation of information technology. For this purpose, in this paper, first, we present a type of novel intelligent deep hybrid neural network algorithm based on a deep bidirectional recurrent neural network integrated with a deep backward propagation neural network. It has realized acoustic analysis, speech recognition and natural language understanding for jointly constituting human-machine voice interactions. Second, we design a voice control motherboard using an embedded chip from the ARM series as the core, and the onboard components include ZigBee, RFID, WIFI, GPRS, a RS232 serial port, USB interfaces and so on. Third, we take advantage of algorithms, software and hardware to make machines “understand” human speech and “think” and “comprehend” human intentions to structure critical components for intelligent vehicles, intelligent offices, intelligent service robots, intelligent industries and so on, which furthers the structure of the intelligent ecology of the Internet of Things. At last, the experimental results denote that the study of the semantics interaction controls based on an embedding has a very good effect, fast speed and high accuracy, consequently realizing the intelligent ecology construction of the Internet of Things.展开更多
Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the ho...Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.展开更多
We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 ...We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.展开更多
Background: Adolescents in developing countries have limited knowledge about the prevention of STIs and unwanted pregnancies. In several African countries, risky sexual behaviour persists, including early sexual debut...Background: Adolescents in developing countries have limited knowledge about the prevention of STIs and unwanted pregnancies. In several African countries, risky sexual behaviour persists, including early sexual debut, multiple sexual partners, economic and sexual exchange, and low condom and contraceptive use. The purpose of this study is to assess the sexual and reproductive health knowledge and behaviour of adolescents in rural Burkina Faso in order to improve their sexual and reproductive health. Method: This was a descriptive cross-sectional study with prospective data collection conducted from 07 March to 04 April 2022 in the area of the Demographic and Health Surveillance System of the Nouna Research Centre. A questionnaire was administered to a randomly selected sample of 1202 adolescents. Results: The mean age of the adolescents was 14.1 years and 56.6% were male. Only 58.2% of the adolescents had ever heard of HIV/AIDS. Of these, 95.7% did not know their HIV status. In addition, 15.8% had ever had sexual intercourse and 2.4% had been sexually active at an early age. Almost 45% had not used any contraceptive method the last time they had sex. Condoms were the most frequently used contraceptive method (47.4%). Among teenagers, 27.6% had been pregnant at least once, 7.3% were married and the average age at marriage was 18.45 years. Almost 7% (6.9%) of teenagers had more than one sexual partner. Conclusion: Adolescents have limited knowledge about reproductive health. Risky sexual behaviour persists. Awareness campaigns need to be intensified to improve their sexual and reproductive health.展开更多
As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the...As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission.展开更多
We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach...We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach about 59 mm of SVL.Vitellogenesis started in June-July,with ovulation occurring during late-October to mid-November,and parturition in mid-spring.Litter size varied from two to six,with a mean of 3.86±0.15 embryos in uterus,and showed a positive correlation with female body mass and SVL.During gestation,a significant increase in the average wet mass of embryos in uterus was evident.In comparison,there were no notable changes in the average dry mass.Juvenile growth data suggest that sexual maturity,both males and females,is reached at 16-17 months of age.Testicles and epididymides exhibited maximal weight during August-September.Testicular regression occurred in September.Mating apparently takes place from mid-summer to early fall.Lipids stored in female fat bodies are used for vitellogenesis and for nutrition during the winter months.In males,the stored lipids appear to be used in reproductive activities during the mating season.展开更多
Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,ar...Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.展开更多
文摘Paris polyphylla Smith is an important medicinal plant that is considered vulnerable in many parts of the world. The species exhibits poor adaptability to changed environment and susceptible to climatic conditions for reproductive vigor. During the present study the species was studied in four different natural niches as well as synthetic habitats to check the adaptability to artificial conditions, its morphological and physiological characters and its interaction in its community so that conservation strategies could be worked out. The present study indicates that P. polyphylla exhibits healthy growth as well as reproduction in undisturbed area with canopy covers over 80%. The plant grows in well-drained rich humus soil and grows well with certain key associated species such as Quercus species, Taxus baccata, Aconitum species, Eupatorium adenophorum, Smilax species etc. Many plants were non-flowering and more than 60% were found non-flowering in its habitat during its flowering season in any particular year. There are clear morphological changes as the flowers stages from pre-fertilization to post-fertilization. Arrangement of anthers in two whorls shows a distinct and unique floral display. Light is an important factor during seed setting and less than 50% shade lowers the seed productivity very significantly. Predators such as slugs and snails are found on the plant. Urgent conservation and new innovative ways are necessary to propagate this economically important plant to ensure its continuity.
基金supported by the Faculty of Sciences and Project Management Program of the Welfare Office of the Universidad Nacional de Colombia under Grant Nos.3733,1150,1302,1567,and 3093Colciencias Scholarship Doctoral Program under Grant No.6172+1 种基金Yoluka NGO,Biodiversity and Conservation Research Foundation under Grant No.001-2014Universidad Manuela Beltran under act 13072019 and Palmasol S.A.Ac001-2014。
文摘Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we explored the main drivers of reproductive output in N.atrata.Results showed that prey abundance and food intake were crucial variables contributing to reproductive output.Multiple linear regression models showed that neonates had high sensitivity(R2=55.29%)to extreme changes in climate,which was strongly related to slug and snail abundance variability and microhabitat quality.Reproductive cycles were markedly different between the sexes,being continuous in males and cyclical in females.Despite this variation,reproductive cycles at the population level were seasonal semi-synchronous.Constant recruitment of neonates all year,multiple clutches,high mating frequency,and continuous sperm production characterized the reproductive phenology of N.atrata.In addition,a significant number of previtellogenic females presented oviductal sperm as well as uterine scars,suggesting a high precocity in the species.The main drivers of reproductive output also differed between the sexes.In females,clutch size and secondary follicle variability were highly related to stomach bolus volume,fat body area,and body mass.In males,height of piles of palm leaves and body mass,rather than intrinsic reproductive traits,were the main drivers of sperm production.Nevertheless,in both cases,the relationship between body mass,prey abundance,and food intake suggests that N.atrata follows the income breeding strategy to compensate for reproductive costs and to maximize fitness.
文摘To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved access to information on various Sexual Reproductive Health topics through Short Messaging Service (SMS) messages. Over the years, the platform has accumulated millions of incoming and outgoing messages, which need to be categorized into key thematic areas for better tracking of sexual reproductive health knowledge gaps among young people. The current manual categorization process of these text messages is inefficient and time-consuming and this study aims to automate the process for improved analysis using text-mining techniques. Firstly, the study investigates the current text message categorization process and identifies a list of categories adopted by counselors over time which are then used to build and train a categorization model. Secondly, the study presents a proof of concept tool that automates the categorization of U-report messages into key thematic areas using the developed categorization model. Finally, it compares the performance and effectiveness of the developed proof of concept tool against the manual system. The study used a dataset comprising 206,625 text messages. The current process would take roughly 2.82 years to categorise this dataset whereas the trained SVM model would require only 6.4 minutes while achieving an accuracy of 70.4% demonstrating that the automated method is significantly faster, more scalable, and consistent when compared to the current manual categorization. These advantages make the SVM model a more efficient and effective tool for categorizing large unstructured text datasets. These results and the proof-of-concept tool developed demonstrate the potential for enhancing the efficiency and accuracy of message categorization on the Zambia U-report platform and other similar text messages-based platforms.
文摘The lack of validated tools to predict how long sow farms will remain PRRS virus-free following successful elimination of the virus has deterred veterinarians and producers from attempting to eliminate the PRRS virus from sow farms. The aim of this study was to use the database of PRRS Risk Assessments for the Breeding Herd in PADRAP to develop and validate an objective risk scoring system for predicting the likelihood of virus introduction in PRRS virus-free sow farms in the US. To overcome the challenges of dealing with a large number of variables, group lasso for logistic regression (GLLR) was applied to a retrospective dataset of PRRS Risk Assessment for the Breeding Herd surveys completed for 704 farms to develop the risk scoring system. The validity of the GLLR risk scoring system was then evaluated by testing its predictive ability on a dataset from a long-term prospective study of 196 sow farms to assess risk factors associated with how long PRRS virus-free sow farms remained PRRS virus-free. Receiver operator characteristic(ROC) curves were estimated to compare the performance of the GLLR risk scoring system to the risk scoring system based on expert opinion (EO), currently used in the PRRS Risk Assessment for the Breeding Herd, for predicting whether herds remained PRRS virus-free for 130 weeks. The GLLR risk scoring system (AUC, 0.76;95% CI, 0.67 - 0.84) performed significantly better than the EO risk scoring system (AUC, 0.36;95% CI, 0.27 - 0.46) for predicting whether to sow farms in the prospective study survived for 130 weeks (p 0.001). Dividing farms into 3 risk groups (low, medium and high) using a low and high cutoff values for the GLLR risk score was informative as the differences in the KM survival curves for the 3 groups were both clinically meaningful and statistically significant. The GLLR risk scoring system used in conjunction with the PRRS Risk Assessment for the Breeding Herd survey delivered through PADRAP appears to have the potential to help veterinarians predict the likelihood of virus introduction in PRRS virus-free sow farms in the US.
文摘Intelligent equipment is a kind of device that is characterized by intelligent sensor interconnections, big data processing, new types of displays, human-machine interaction and so on for the new generation of information technology. For this purpose, in this paper, first, we present a type of novel intelligent deep hybrid neural network algorithm based on a deep bidirectional recurrent neural network integrated with a deep backward propagation neural network. It has realized acoustic analysis, speech recognition and natural language understanding for jointly constituting human-machine voice interactions. Second, we design a voice control motherboard using an embedded chip from the ARM series as the core, and the onboard components include ZigBee, RFID, WIFI, GPRS, a RS232 serial port, USB interfaces and so on. Third, we take advantage of algorithms, software and hardware to make machines “understand” human speech and “think” and “comprehend” human intentions to structure critical components for intelligent vehicles, intelligent offices, intelligent service robots, intelligent industries and so on, which furthers the structure of the intelligent ecology of the Internet of Things. At last, the experimental results denote that the study of the semantics interaction controls based on an embedding has a very good effect, fast speed and high accuracy, consequently realizing the intelligent ecology construction of the Internet of Things.
基金supported by the National Key Research and Development Program of China,2018YFD0500400。
文摘Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.
基金supported by grants from the Special Foundation for Basic Work of the Science and Technology Ministry of China (2022FY100500-2)National Natural Science Foundation of China (31470471)+2 种基金Hainan Key Program of Science and Technology (ZDXM20110008)Hainan Specially Supporting Discipline of ZoologyWenzhou Ecological Park Research Project。
文摘We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.
文摘Background: Adolescents in developing countries have limited knowledge about the prevention of STIs and unwanted pregnancies. In several African countries, risky sexual behaviour persists, including early sexual debut, multiple sexual partners, economic and sexual exchange, and low condom and contraceptive use. The purpose of this study is to assess the sexual and reproductive health knowledge and behaviour of adolescents in rural Burkina Faso in order to improve their sexual and reproductive health. Method: This was a descriptive cross-sectional study with prospective data collection conducted from 07 March to 04 April 2022 in the area of the Demographic and Health Surveillance System of the Nouna Research Centre. A questionnaire was administered to a randomly selected sample of 1202 adolescents. Results: The mean age of the adolescents was 14.1 years and 56.6% were male. Only 58.2% of the adolescents had ever heard of HIV/AIDS. Of these, 95.7% did not know their HIV status. In addition, 15.8% had ever had sexual intercourse and 2.4% had been sexually active at an early age. Almost 45% had not used any contraceptive method the last time they had sex. Condoms were the most frequently used contraceptive method (47.4%). Among teenagers, 27.6% had been pregnant at least once, 7.3% were married and the average age at marriage was 18.45 years. Almost 7% (6.9%) of teenagers had more than one sexual partner. Conclusion: Adolescents have limited knowledge about reproductive health. Risky sexual behaviour persists. Awareness campaigns need to be intensified to improve their sexual and reproductive health.
基金partially supported by the Namibia Students Financial Assistance Fund(NSFAF)Kreditanstalt für Wiederaufbau(KfW)-University of Namibia(UNAM,BMZ Ref.2015.67.015)+2 种基金funded by the project TROPIBIO NORTE-01-0145-FEDER-000046supported by Norte Portugal Regional Operational Programme(NORTE2020)developed in the framework of the“Twin Lab CIBIO/UNAM”(UNESCO Chair Life on Land)。
文摘As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission.
基金funded by the Biology Major of the Facultad de Estudios Superiores Zaragoza,Universidad Nacional Autónoma de México(UNAM)Scientific collecting permit issued by Semarnat(SGPA/DGVS 12013/12)。
文摘We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach about 59 mm of SVL.Vitellogenesis started in June-July,with ovulation occurring during late-October to mid-November,and parturition in mid-spring.Litter size varied from two to six,with a mean of 3.86±0.15 embryos in uterus,and showed a positive correlation with female body mass and SVL.During gestation,a significant increase in the average wet mass of embryos in uterus was evident.In comparison,there were no notable changes in the average dry mass.Juvenile growth data suggest that sexual maturity,both males and females,is reached at 16-17 months of age.Testicles and epididymides exhibited maximal weight during August-September.Testicular regression occurred in September.Mating apparently takes place from mid-summer to early fall.Lipids stored in female fat bodies are used for vitellogenesis and for nutrition during the winter months.In males,the stored lipids appear to be used in reproductive activities during the mating season.
基金Supported by the Laoshan Laboratory (No.LSKJ202204005)the Mount Tai Scholar Climbing Plan to Song SUNthe Open Fund of CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences (No.KLMEES201801)
文摘Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.