Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally ...Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally friendly and cost-effective alternatives.In this study,we developed a facile impregnation method to fabricate unsaturated Co single-atoms with a tricoordinated Co_(1)O_(3)H_(x) structure by regulating silanol nests in purely siliceous Beta zeolites.Detailed PDH catalytic tests and characterizations revealed a positive correlation between the presence of silanol nests and enhanced catalytic activity.Additionally,the unsaturated Co single-atoms exhibited a carbon deposition rate more than an order of magnitude slower than that of Co nanoparticles.Notably,the optimized Co_(0.3%)/deAl-meso-Beta catalyst achieved a record-high propylene formation rate of 21.2 mmol_(C3H6) g_(cat)^(-1) h^(-1),with an exceptional propylene selectivity of 99.1%at 550℃.Moreover,the Co_(0.3%)/deAl-meso-Beta catalyst demonstrated excellent stability,with negligible deactivation after 5 consecutive regeneration cycles.This study emphasizes the pivotal role of silanol nests of zeolites in stabilizing and modulating the coordination environment of metallic active sites,providing valuable insights for the design of high-activity,high-stability,and low-cost PDH catalysts.展开更多
The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. ...The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. Von Brunn’s nests and cysts are submucosal benign urothelial processes, related to irritative stimuli (calculi and urinary infections), characterized by an invagination with buds and clusters of normal urothelium in the lamina propria. They are common findings in the urinary bladder of human beings, but few cases have been described in dogs and cats. We report macroscopic, histopathological and, in one case, immunohistochemical features of these rare forms in the left ureters of two cats. Macroscopic evidence during surgery of ureteral nodules in two cats was accompanied by histopathological diagnosis and, in one case, by immunohistochemical assessment. Histopathology was coherent with a rare condition characterized by nests and islands of normal urothelium in the lamina propria and submucosa, with formation of cysts and moderate focal subacute inflammation. In one case epithelial cells of the nests showed well differentiated urothelial cells with an intense immunoreactivity to pan-cytokeratin (CK AE1/AE3), CK19 in the first outer layers, a slight immunoreactivity to CK20 and a low proliferative activity using MIB-1 (Ki67).展开更多
We investigated a breeding population of Common Coots (Fulica atra) from April to June in 2008 and 2009.We found that each pair of coots built display platforms beside their nest in their territory during the breeding...We investigated a breeding population of Common Coots (Fulica atra) from April to June in 2008 and 2009.We found that each pair of coots built display platforms beside their nest in their territory during the breeding season.On average,3.1 (range 2-7) platforms were built by each pair of coots.Display platforms were simpler with less coverage and were significantly lower above the water surface than nests; however,their depth below the water surface was not significantly different.Platforms were primarily used for roosting,preening and mating in the breeding season,but they were also used to store animal food.In the breeding season,nest was usually built later than platforms,the use ratio (total and daily frequency) of platforms decreased after nest was built,and more mating behavior was performed on the nest than on the platform.We compared the use ratio of both sexes to the nest and platforms in different breeding phases; the results show that females used the nest more than the platforms,while males used the platforms more than the females,suggesting that females pay more attention to breeding,while males put more energy in territorial defense.Since coots are territorial during the breeding season,the platforms may play an important role in confirming and recognizing territorial boundaries.展开更多
We investigate the plant composition in the Skuas nest at Hennequin Point, located in the Admiralty Bay Area, King George Island, Antarctica. Sample of 61 activity nests were analyzed. 21 plant and lichenized fungi sp...We investigate the plant composition in the Skuas nest at Hennequin Point, located in the Admiralty Bay Area, King George Island, Antarctica. Sample of 61 activity nests were analyzed. 21 plant and lichenized fungi species were found in the nest composition, being the mosses Sanioniauncinata (Hedw.) Loeske and Polytrichastrumalpinum (Hedw) G. S. Smith the most frequent species found in the Skuas nests. Usneaantarctica Du Rietz was the most frequent lichen and the grass Deschampsiaantarctica Desv was the most frequent flowering plant found in the nests. These results contribute for the environmental menagement of the Admiralty Bay area research activities.展开更多
Edible bird＇s nest （EBN） is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefits. Some studies have reported the biochemical compos...Edible bird＇s nest （EBN） is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefits. Some studies have reported the biochemical compositions of EBN, graded on the basis of colour, nitrate and nitrite contents. Other studies have shown significant biological effects, while ongoing research is in progress to explore potential pharmacological applications. The high demand for EBNs in the global market has forced the local regulatory bodies to monitor swiftlet farming activities, including the EBN cleaning process. Furthermore, numerous techniques have been developed to authenticate EBN; proteomics is likely to be the most promising of these methods. However, there are limited numbers of relevant protein sequences deposited at the database. More research is needed at the molecular level to explore the mechanisms behind the biological functions, such as bone strength improvement, skin rejuvenation, epidermal growth factor activity and cell proliferation.The current and future prospects of EBN and swiftlet farming are critically reviewed in this article.展开更多
Background:Research activities have often been thought to potentially influence avian nesting success by increasing nest predation rates.Although recent studies of species building open nests and cavity nests suggest ...Background:Research activities have often been thought to potentially influence avian nesting success by increasing nest predation rates.Although recent studies of species building open nests and cavity nests suggest that research disturbance does not generally induce nest predation,whether it is also the case in species building domednests remains unknown.In birds,domed-nest species exist in about half of the passerine families,and research disturbance to the domed nests may differ from that to the nests of other types for their different nest structures.Methods:We investigated if research activities affected nest predation rate by analyzing the relationships of the daily nest survival rate with the research activities at the egg and nestling stages of a domed-nest species,the Silverthroated Tit(Aegithalos glaucogularis).Results:Our results showed that nest daily survival rate was significantly affected by the laying date and nest age during the egg stage,and by the hatching date only during the nestling stage.By contrast,there were no significant effects of research activities,in terms of visiting nests and filming nests,on the nest survival of the Silver-throated Tit at both the egg and nestling stages.Conclusions:Our results coincide with the findings in species building other types of nests that research activities do not always have negative effects on avian nesting success.展开更多
Background: Nest construction is a key element of avian reproductive behaviour and the result is often a complex structure that is used for incubation of eggs, which represents an extended phenotype. It is known that ...Background: Nest construction is a key element of avian reproductive behaviour and the result is often a complex structure that is used for incubation of eggs, which represents an extended phenotype. It is known that nest construction is a plastic behaviour but the extent to which plasticity is observed in a single species with a wide geographical distribution is largely unknown. This study sought to better understand variation in nest size and composition across a very wide geographical area. The hypothesis suggested that location would affect size but not composition of nests of the European Pied Flycatcher (Ficedula hypoleuca). Methods: Nests and reproductive data were collected from seventeen study sites, spread over 6° of latitude and 3.3° of longitude on the island of Great Britain. Dimensions of nests were measured before they were deconstructed to determine the masses and types materials used in the outer nest and the cup lining. Results: Geographical variation was observed in base thickness of nests but not many other dimensions. Nests varied in composition but were mainly made of leaf, moss, bark, grass, root and fern. Moss was used more to the north and east of the study area compared with more leaf mass towards the south and west. The species of leaf and bark used in the nests varied between geographical locations. Additionally, the use of leaves or bark from a particular tree species did not reflect the incidence of the tree species in the immediate territory. Conclusions: This study showed that nest composition was affected by geographical location over a wide area. Variation between nests at each location was high and so it was concluded that differences in nest composition reflect individual selection of materials but evidence is such that it remains unclear whether this is deliberate to fulfil a specific role in the nest, or simply opportunistic with birds simply picking up materials with the appropriate characteristics as they find them outside their nestbox.展开更多
In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribut...In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.展开更多
Objectives:Edible bird nest hydrolysates(EBNHs)are renowned for their health benefits.The study aimed to determine their functional effects as an ingredient in cocoa-flavoured soy-based powder drink mix(PDM).The glyca...Objectives:Edible bird nest hydrolysates(EBNHs)are renowned for their health benefits.The study aimed to determine their functional effects as an ingredient in cocoa-flavoured soy-based powder drink mix(PDM).The glycaemic and satiety effects of the product were also studied.Materials and Methods:The product was enriched with a reasonably low amount of spray-dried EBNH.The product’s functional effects with respect to in vitro angiotensin-converting enzyme(ACE)inhibitory activity and human red blood cell membrane stabilization(RBCMS)activity were evaluated using its water extract(90-95℃).The glycaemic and satiety impacts were evaluated in twelve and thirty subjects,respectively,who consumed 250 mL of the product,which contained 25 g of available carbohydrates.Results:The enriched PDM ACE inhibitory activity and RBCMS activity were significantly higher(P<0.05)than those that were devoid of EBNH.Two hundred and forty milliliters(12.5%(125 mg/mL))of PDM(containing 3.0%EBNH,75.44%soybean powder,20%cocoa powder,0.5%xanthan gum,1.0%silicon dioxide,and 0.06%sucralose(mass fraction))provides approximately 3.7 kcal/g energy.The 250 mL meal(consistency index of 14.17 Pa·sn)is high in protein and dietary fibre.The product’s glycaemic index(GI)and glycaemic load(GL)are low,24 and 6.0,respectively,raising a normal level of 2-h postprandial blood glucose(<6 mmol/L)and satisfying hunger for approximately 2.5 h.Conclusions:EBNH,as an ingredient,enhances the antihypertensive and anti-inflammatory properties of PDM.The overall findings suggest that the formulated PDM is a wellness food product capable of promoting good human health,including for dieters and individuals with diabetes.展开更多
The core components of an aircraft and the source of its lift are its wings,but lift generation is disrupted by the high temperature and pressure generated on the wing surface when an aircraft gun is fired.Here,to inv...The core components of an aircraft and the source of its lift are its wings,but lift generation is disrupted by the high temperature and pressure generated on the wing surface when an aircraft gun is fired.Here,to investigate how this process influences the aerodynamic parameters of aircraft wings,the k-ωshearstress-transport turbulence model and the nested dynamic grid technique are used to analyze numerically the transient process of the muzzle jet of a 30-mm small-caliber aircraft gun in highaltitude(10 km)flight with an incoming Mach number of Ma=0.8.For comparison,two other models are established,one with no projectile and the other with no wing.The results indicate that when the aircraft gun is fired,the muzzle jet acts on the wing,creating a pressure field thereon.The uneven distribution of high pressure greatly reduces the lift of the aircraft,causing oscillations in its drag and disrupting its dynamic balance,thereby affecting its flight speed and attitude.Meanwhile,the muzzle jet is obstructed by the wing,and its flow field is distorted and deformed,developing upward toward the wing.Because of the influence of the incoming flow,the shockwave front of the projectile changes from a smooth spherical shape to an irregular one,and the motion parameters of the projectile are also greatly affected by oscillations.The present results provide an important theoretical basis for how the guns of fighter aircraft influence the aerodynamic performance of the wings.展开更多
Provision of nest boxes is necessary for laying hens,especially in non-cage systems.This study investigated the effects of nest width on nest utilization and mislaid eggs.Hy-Line Browns hens were transferred from conv...Provision of nest boxes is necessary for laying hens,especially in non-cage systems.This study investigated the effects of nest width on nest utilization and mislaid eggs.Hy-Line Browns hens were transferred from conventional cages to perchery pens at 12 weeks of age.Two experiments were conducted to mutually verify the hypothesis that narrowing group nests would improve nest utilization and reduce mislaid eggs.In experiment 1,group nests of 150 cm wide in two pens were partitioned at intervals of 50 cm and 37 cm,respectively.In experiment 2,partition panels were removed after acclimation.The number of mislaid eggs and nest eggs in each pre-set section were compared.Results indicated that narrowing group nests had positive effects on improving usage uniformity and efficiency of group nests.Nest eggs were more evenly distributed on the egg belt in both narrowed group nests,which was indicated by the significant decrease of variance among different sections(p<0.001).The proportion of mislaid eggs decreased by 3.5%in 37 cm treatment(p<0.05)and 4.7% in 50 cm treatment(p<0.001),respectively.As expected,reuse of the 150 cm group nests after removal of partition panels lowered the usage uniformity of group nests.A growth of three percentage points was found for the proportion of mislaid eggs after removing the partition panels in 50 cm treatment.The present results indicated that it is the width of the nest box that works for a better use of group nests.In conclusion,adding partition panels at intervals of 50 cm and 37 cm in group nests both are effective on nest usage and decreasing the occurrence of mislaid eggs.展开更多
Despite the importance of maternally selected nests in shaping offspring phenotypes,our understanding of how the nest environment affects embryonic development and offspring traits of most non-avian reptiles is rather...Despite the importance of maternally selected nests in shaping offspring phenotypes,our understanding of how the nest environment affects embryonic development and offspring traits of most non-avian reptiles is rather limited largely due to the logistical difficulty in locating their nests.To identify the relative contributions of environmental(temporal[seasonal]and spatial[nest-site])and intrinsic(clutch)factors on embryonic development and offspring traits,we conducted a cross-fostering experiment by swapping eggs between maternally-selected nests of the toad-headed agama(Phrynocephalus przewalskii)in the field.We found that nest environment explained a large proportion of variation in incubation duration,hatching success,and offspring size and growth.In contrast,clutch only explained a small proportion of variation in these embryonic and offspring traits.More significantly,compared with spatial effects,seasonal effects explained more phenotypic variation in both embryonic development and offspring traits.Eggs laid early in the nesting season had longer incubation durations and produced smaller hatchlings with higher post-hatching growth rates than did later-laid eggs.Consequently,hatchlings from early-laid eggs reached larger body sizes prior to winter.In addition,we found that female toad-headed agama did not select nests specific to reaction norms of their own offspring because hatchlings from original or translocated nests had similar phenotypic traits.Overall,our study demonstrates the importance of seasonal variation in nest environments in determining embryonic development and offspring phenotypes,which has not been widely appreciated at least in non-avian reptiles.展开更多
Vespa velutina is an invasive hornet species that is colonising Europe,generating considerable impacts on honeybees,beekeeping and biodiversity.Control and early warning strategies for this species are mainly based on...Vespa velutina is an invasive hornet species that is colonising Europe,generating considerable impacts on honeybees,beekeeping and biodiversity.Control and early warning strategies for this species are mainly based on monitoring plans and procedures of nest detection and destruction.Technological tools(harmonic radar,radio-telemetry)have been developed to increase the probabilities of nest detection in new outbreaks.Since hornets are able to regulate nest temperature,thermography may represent an additional technique that may be used,both alone or in support to other techniques.In this study,the viability of thermal imaging in detecting nests of V.velutina was evaluated in controlled conditions.The influence of different environmental and operative variables(time of the day,presence/absence of leaves covering the nest,distance between the nest and the operator)were tested on three nests detected during August 2018 in Italy.All the nests were detectable by thermal imaging,but environmental and operative variables affect their detectability.The temperature difference between the nests and the surrounding reaches its maximum before sunrise and without a tree canopy covering the nests.Although nests were visible in some cases from 30 m,the detectability was higher at shorter distances,even if this variable may also depend on infrared camera resolution.An increase in the environmental temperature also generates a decrease of nest detectability.Although some limitations could occur,these results show the applicability of thermography in detecting V velutina nests before the beginning of the reproductive phase,and consequently its potentiality in control strategies.展开更多
Edible birds’nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is th...Edible birds’nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is therefore considered a sustainable means of production,whereas the expansion of other agricultural activities often relies on the degradation of natural resources.This study examines the relationship between natural resources and agricultural livelihoods,focusing on Indonesian EBN farmers.Using survey data that we collected in 2017,combined with satellite information on the extent of the forest in Central Kalimantan,Indonesia,we measured production efficiency and identified the natural and social factors that enhance production performance.The results show that a forest extent ranging between 2,000 and 6,000 meters from nesting building is positively associated with the production efficiency of EBN farming,perhaps because extensive forest could help swiftlets to collect food and build nests.Conversely,while EBN farming is a sustainable and profitable option,the initial costs of constructing buildings to house swiftlets may deter farmers from participating in the process.展开更多
This paper studies the status of empty nest only-child families in urban China,using data about these families taken from a 2015 survey conducted by the Institute of Population and Labor Economics,Chinese Academy of S...This paper studies the status of empty nest only-child families in urban China,using data about these families taken from a 2015 survey conducted by the Institute of Population and Labor Economics,Chinese Academy of Social Sciences.Factors that determine the timing of empty nest periods and their duration for only-child parents are also analyzed.The data shows that more than half of the only-child parents surveyed in 2015 lived in empty nests.Some of these parents had been empty-nesters for as many as 25 years.During the life cycle of families,the empty nest status of elderly only-child parents shows different characteristics at different stages,as the only-children begin attending universities,start to work,get married,and have children of their own.There are empty nest periods in only-child families when the only-child leaves the parents for several years and periods when the child returns home and lives with parents for years.The living arrangements of only-child parents depend mainly on changes in the life needs of their only-children.Intergenerational support is focused on meeting the needs of only-children.展开更多
Edible birds'nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is...Edible birds'nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is therefore considered a sustainable means of production,whereas the expansion of other agricultural activities often relies on the degradation of natural resources.This study examines the relationship between natural resources and agricultural livelihoods,focusing on Indonesian EBN farmers.Using survey data that we collected In 2017,combined with satellite information on the extent of the forest in Central Kalimantan,Indonesia,we measured production efficiency and identified the natural and social factors that enhance production performance.The results show that a forest extent ranging between2,000 and 6,000 meters from nesting building is positively associated with the production efficiency of EBN farming,perhaps because extensive forest could help swiftlets to collect food and build nests.Conversely,while EBN farming is a sustainable and profitable option,the initial costs of constructing buildings to house swiftlets may deter farmers from participating in the process.展开更多
Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Bo...Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Botanical Garden(XTBG)and the Institute of Zoology-revealed that the assassin bug Pahabengkakia piliceps weaponizes resin from stingless bee nests to trick its prey.展开更多
This review article provides a comprehensive analysis of nesting optimization algorithms in the shipbuilding industry,emphasizing their role in improving material utilization,minimizing waste,and enhancing production ...This review article provides a comprehensive analysis of nesting optimization algorithms in the shipbuilding industry,emphasizing their role in improving material utilization,minimizing waste,and enhancing production efficiency.The shipbuilding process involves the complex cutting and arrangement of steel plates,making the optimization of these operations vital for cost-effectiveness and sustainability.Nesting algorithms are broadly classified into four categories:exact,heuristic,metaheuristic,and hybrid.Exact algorithms ensure optimal solutions but are computationally demanding.In contrast,heuristic algorithms deliver quicker results using practical rules,although they may not consistently achieve optimal outcomes.Metaheuristic algorithms combine multiple heuristics to effectively explore solution spaces,striking a balance between solution quality and computational efficiency.Hybrid algorithms integrate the strengths of different approaches to further enhance performance.This review systematically assesses these algorithms using criteria such as material dimensions,part geometry,component layout,and computational efficiency.The findings highlight the significant potential of advanced nesting techniques to improve material utilization,reduce production costs,and promote sustainable practices in shipbuilding.By adopting suitable nesting solutions,shipbuilders can achieve greater efficiency,optimized resource management,and superior overall performance.Future research directions should focus on integrating machine learning and real-time adaptability to further enhance nesting algorithms,paving the way for smarter,more sustainable manufacturing practices in the shipbuilding industry.展开更多
文摘Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally friendly and cost-effective alternatives.In this study,we developed a facile impregnation method to fabricate unsaturated Co single-atoms with a tricoordinated Co_(1)O_(3)H_(x) structure by regulating silanol nests in purely siliceous Beta zeolites.Detailed PDH catalytic tests and characterizations revealed a positive correlation between the presence of silanol nests and enhanced catalytic activity.Additionally,the unsaturated Co single-atoms exhibited a carbon deposition rate more than an order of magnitude slower than that of Co nanoparticles.Notably,the optimized Co_(0.3%)/deAl-meso-Beta catalyst achieved a record-high propylene formation rate of 21.2 mmol_(C3H6) g_(cat)^(-1) h^(-1),with an exceptional propylene selectivity of 99.1%at 550℃.Moreover,the Co_(0.3%)/deAl-meso-Beta catalyst demonstrated excellent stability,with negligible deactivation after 5 consecutive regeneration cycles.This study emphasizes the pivotal role of silanol nests of zeolites in stabilizing and modulating the coordination environment of metallic active sites,providing valuable insights for the design of high-activity,high-stability,and low-cost PDH catalysts.
文摘The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. Von Brunn’s nests and cysts are submucosal benign urothelial processes, related to irritative stimuli (calculi and urinary infections), characterized by an invagination with buds and clusters of normal urothelium in the lamina propria. They are common findings in the urinary bladder of human beings, but few cases have been described in dogs and cats. We report macroscopic, histopathological and, in one case, immunohistochemical features of these rare forms in the left ureters of two cats. Macroscopic evidence during surgery of ureteral nodules in two cats was accompanied by histopathological diagnosis and, in one case, by immunohistochemical assessment. Histopathology was coherent with a rare condition characterized by nests and islands of normal urothelium in the lamina propria and submucosa, with formation of cysts and moderate focal subacute inflammation. In one case epithelial cells of the nests showed well differentiated urothelial cells with an intense immunoreactivity to pan-cytokeratin (CK AE1/AE3), CK19 in the first outer layers, a slight immunoreactivity to CK20 and a low proliferative activity using MIB-1 (Ki67).
基金supported by the National Natural Science Foundation of China (No. 200904012)the Jiangxi Agricultural University Research Start Fund for Doctor (09003274)
文摘We investigated a breeding population of Common Coots (Fulica atra) from April to June in 2008 and 2009.We found that each pair of coots built display platforms beside their nest in their territory during the breeding season.On average,3.1 (range 2-7) platforms were built by each pair of coots.Display platforms were simpler with less coverage and were significantly lower above the water surface than nests; however,their depth below the water surface was not significantly different.Platforms were primarily used for roosting,preening and mating in the breeding season,but they were also used to store animal food.In the breeding season,nest was usually built later than platforms,the use ratio (total and daily frequency) of platforms decreased after nest was built,and more mating behavior was performed on the nest than on the platform.We compared the use ratio of both sexes to the nest and platforms in different breeding phases; the results show that females used the nest more than the platforms,while males used the platforms more than the females,suggesting that females pay more attention to breeding,while males put more energy in territorial defense.Since coots are territorial during the breeding season,the platforms may play an important role in confirming and recognizing territorial boundaries.
基金The authors thank the Brazilian National Council of Sci-entific Research-CNPq(process 574018/2008 e 314664/2009-2),FAPERJ(process E-26/170.023/2008)and MMA/MCT/PROANTAR for the financial support.
文摘We investigate the plant composition in the Skuas nest at Hennequin Point, located in the Admiralty Bay Area, King George Island, Antarctica. Sample of 61 activity nests were analyzed. 21 plant and lichenized fungi species were found in the nest composition, being the mosses Sanioniauncinata (Hedw.) Loeske and Polytrichastrumalpinum (Hedw) G. S. Smith the most frequent species found in the Skuas nests. Usneaantarctica Du Rietz was the most frequent lichen and the grass Deschampsiaantarctica Desv was the most frequent flowering plant found in the nests. These results contribute for the environmental menagement of the Admiralty Bay area research activities.
文摘Edible bird＇s nest （EBN） is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefits. Some studies have reported the biochemical compositions of EBN, graded on the basis of colour, nitrate and nitrite contents. Other studies have shown significant biological effects, while ongoing research is in progress to explore potential pharmacological applications. The high demand for EBNs in the global market has forced the local regulatory bodies to monitor swiftlet farming activities, including the EBN cleaning process. Furthermore, numerous techniques have been developed to authenticate EBN; proteomics is likely to be the most promising of these methods. However, there are limited numbers of relevant protein sequences deposited at the database. More research is needed at the molecular level to explore the mechanisms behind the biological functions, such as bone strength improvement, skin rejuvenation, epidermal growth factor activity and cell proliferation.The current and future prospects of EBN and swiftlet farming are critically reviewed in this article.
基金This study was funded by the National Natural Science Foundation of China(Grant Nos.31970421,31472011,31101644).
文摘Background:Research activities have often been thought to potentially influence avian nesting success by increasing nest predation rates.Although recent studies of species building open nests and cavity nests suggest that research disturbance does not generally induce nest predation,whether it is also the case in species building domednests remains unknown.In birds,domed-nest species exist in about half of the passerine families,and research disturbance to the domed nests may differ from that to the nests of other types for their different nest structures.Methods:We investigated if research activities affected nest predation rate by analyzing the relationships of the daily nest survival rate with the research activities at the egg and nestling stages of a domed-nest species,the Silverthroated Tit(Aegithalos glaucogularis).Results:Our results showed that nest daily survival rate was significantly affected by the laying date and nest age during the egg stage,and by the hatching date only during the nestling stage.By contrast,there were no significant effects of research activities,in terms of visiting nests and filming nests,on the nest survival of the Silver-throated Tit at both the egg and nestling stages.Conclusions:Our results coincide with the findings in species building other types of nests that research activities do not always have negative effects on avian nesting success.
文摘Background: Nest construction is a key element of avian reproductive behaviour and the result is often a complex structure that is used for incubation of eggs, which represents an extended phenotype. It is known that nest construction is a plastic behaviour but the extent to which plasticity is observed in a single species with a wide geographical distribution is largely unknown. This study sought to better understand variation in nest size and composition across a very wide geographical area. The hypothesis suggested that location would affect size but not composition of nests of the European Pied Flycatcher (Ficedula hypoleuca). Methods: Nests and reproductive data were collected from seventeen study sites, spread over 6° of latitude and 3.3° of longitude on the island of Great Britain. Dimensions of nests were measured before they were deconstructed to determine the masses and types materials used in the outer nest and the cup lining. Results: Geographical variation was observed in base thickness of nests but not many other dimensions. Nests varied in composition but were mainly made of leaf, moss, bark, grass, root and fern. Moss was used more to the north and east of the study area compared with more leaf mass towards the south and west. The species of leaf and bark used in the nests varied between geographical locations. Additionally, the use of leaves or bark from a particular tree species did not reflect the incidence of the tree species in the immediate territory. Conclusions: This study showed that nest composition was affected by geographical location over a wide area. Variation between nests at each location was high and so it was concluded that differences in nest composition reflect individual selection of materials but evidence is such that it remains unclear whether this is deliberate to fulfil a specific role in the nest, or simply opportunistic with birds simply picking up materials with the appropriate characteristics as they find them outside their nestbox.
文摘In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.
基金supported by the Universiti Kebangsaan Malaysia(UKM)through the research project grant GUP-2018-059.
文摘Objectives:Edible bird nest hydrolysates(EBNHs)are renowned for their health benefits.The study aimed to determine their functional effects as an ingredient in cocoa-flavoured soy-based powder drink mix(PDM).The glycaemic and satiety effects of the product were also studied.Materials and Methods:The product was enriched with a reasonably low amount of spray-dried EBNH.The product’s functional effects with respect to in vitro angiotensin-converting enzyme(ACE)inhibitory activity and human red blood cell membrane stabilization(RBCMS)activity were evaluated using its water extract(90-95℃).The glycaemic and satiety impacts were evaluated in twelve and thirty subjects,respectively,who consumed 250 mL of the product,which contained 25 g of available carbohydrates.Results:The enriched PDM ACE inhibitory activity and RBCMS activity were significantly higher(P<0.05)than those that were devoid of EBNH.Two hundred and forty milliliters(12.5%(125 mg/mL))of PDM(containing 3.0%EBNH,75.44%soybean powder,20%cocoa powder,0.5%xanthan gum,1.0%silicon dioxide,and 0.06%sucralose(mass fraction))provides approximately 3.7 kcal/g energy.The 250 mL meal(consistency index of 14.17 Pa·sn)is high in protein and dietary fibre.The product’s glycaemic index(GI)and glycaemic load(GL)are low,24 and 6.0,respectively,raising a normal level of 2-h postprandial blood glucose(<6 mmol/L)and satisfying hunger for approximately 2.5 h.Conclusions:EBNH,as an ingredient,enhances the antihypertensive and anti-inflammatory properties of PDM.The overall findings suggest that the formulated PDM is a wellness food product capable of promoting good human health,including for dieters and individuals with diabetes.
基金supported by the National Natural Science Foundation of China(Grant No.12402268)the Fundamental Research Funds for the Central Universities(Grant No.30925010410)。
文摘The core components of an aircraft and the source of its lift are its wings,but lift generation is disrupted by the high temperature and pressure generated on the wing surface when an aircraft gun is fired.Here,to investigate how this process influences the aerodynamic parameters of aircraft wings,the k-ωshearstress-transport turbulence model and the nested dynamic grid technique are used to analyze numerically the transient process of the muzzle jet of a 30-mm small-caliber aircraft gun in highaltitude(10 km)flight with an incoming Mach number of Ma=0.8.For comparison,two other models are established,one with no projectile and the other with no wing.The results indicate that when the aircraft gun is fired,the muzzle jet acts on the wing,creating a pressure field thereon.The uneven distribution of high pressure greatly reduces the lift of the aircraft,causing oscillations in its drag and disrupting its dynamic balance,thereby affecting its flight speed and attitude.Meanwhile,the muzzle jet is obstructed by the wing,and its flow field is distorted and deformed,developing upward toward the wing.Because of the influence of the incoming flow,the shockwave front of the projectile changes from a smooth spherical shape to an irregular one,and the motion parameters of the projectile are also greatly affected by oscillations.The present results provide an important theoretical basis for how the guns of fighter aircraft influence the aerodynamic performance of the wings.
基金This study was financially supported by the Developing Key Equipment for Digital Management and Monitoring Environment in Animal Production Modern Agricultural Industry Technology System(2013AA10230602)the Special Fund for Cultivation and Evolution of Beijing Innovative Base(Z171100002217018).
文摘Provision of nest boxes is necessary for laying hens,especially in non-cage systems.This study investigated the effects of nest width on nest utilization and mislaid eggs.Hy-Line Browns hens were transferred from conventional cages to perchery pens at 12 weeks of age.Two experiments were conducted to mutually verify the hypothesis that narrowing group nests would improve nest utilization and reduce mislaid eggs.In experiment 1,group nests of 150 cm wide in two pens were partitioned at intervals of 50 cm and 37 cm,respectively.In experiment 2,partition panels were removed after acclimation.The number of mislaid eggs and nest eggs in each pre-set section were compared.Results indicated that narrowing group nests had positive effects on improving usage uniformity and efficiency of group nests.Nest eggs were more evenly distributed on the egg belt in both narrowed group nests,which was indicated by the significant decrease of variance among different sections(p<0.001).The proportion of mislaid eggs decreased by 3.5%in 37 cm treatment(p<0.05)and 4.7% in 50 cm treatment(p<0.001),respectively.As expected,reuse of the 150 cm group nests after removal of partition panels lowered the usage uniformity of group nests.A growth of three percentage points was found for the proportion of mislaid eggs after removing the partition panels in 50 cm treatment.The present results indicated that it is the width of the nest box that works for a better use of group nests.In conclusion,adding partition panels at intervals of 50 cm and 37 cm in group nests both are effective on nest usage and decreasing the occurrence of mislaid eggs.
基金supported by grants from The Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)the National Natural Science Foundation of China(31525006,31801977,31971419)Young Elite Scientists Sponsorship Program by CAST and ISZS for S.L.,and the National Key Research and Development Program of China(2016YFC0503200).
文摘Despite the importance of maternally selected nests in shaping offspring phenotypes,our understanding of how the nest environment affects embryonic development and offspring traits of most non-avian reptiles is rather limited largely due to the logistical difficulty in locating their nests.To identify the relative contributions of environmental(temporal[seasonal]and spatial[nest-site])and intrinsic(clutch)factors on embryonic development and offspring traits,we conducted a cross-fostering experiment by swapping eggs between maternally-selected nests of the toad-headed agama(Phrynocephalus przewalskii)in the field.We found that nest environment explained a large proportion of variation in incubation duration,hatching success,and offspring size and growth.In contrast,clutch only explained a small proportion of variation in these embryonic and offspring traits.More significantly,compared with spatial effects,seasonal effects explained more phenotypic variation in both embryonic development and offspring traits.Eggs laid early in the nesting season had longer incubation durations and produced smaller hatchlings with higher post-hatching growth rates than did later-laid eggs.Consequently,hatchlings from early-laid eggs reached larger body sizes prior to winter.In addition,we found that female toad-headed agama did not select nests specific to reaction norms of their own offspring because hatchlings from original or translocated nests had similar phenotypic traits.Overall,our study demonstrates the importance of seasonal variation in nest environments in determining embryonic development and offspring phenotypes,which has not been widely appreciated at least in non-avian reptiles.
文摘Vespa velutina is an invasive hornet species that is colonising Europe,generating considerable impacts on honeybees,beekeeping and biodiversity.Control and early warning strategies for this species are mainly based on monitoring plans and procedures of nest detection and destruction.Technological tools(harmonic radar,radio-telemetry)have been developed to increase the probabilities of nest detection in new outbreaks.Since hornets are able to regulate nest temperature,thermography may represent an additional technique that may be used,both alone or in support to other techniques.In this study,the viability of thermal imaging in detecting nests of V.velutina was evaluated in controlled conditions.The influence of different environmental and operative variables(time of the day,presence/absence of leaves covering the nest,distance between the nest and the operator)were tested on three nests detected during August 2018 in Italy.All the nests were detectable by thermal imaging,but environmental and operative variables affect their detectability.The temperature difference between the nests and the surrounding reaches its maximum before sunrise and without a tree canopy covering the nests.Although nests were visible in some cases from 30 m,the detectability was higher at shorter distances,even if this variable may also depend on infrared camera resolution.An increase in the environmental temperature also generates a decrease of nest detectability.Although some limitations could occur,these results show the applicability of thermography in detecting V velutina nests before the beginning of the reproductive phase,and consequently its potentiality in control strategies.
基金This work was supported by JSPS KAKENHI[Grant Number JP19H04340].
文摘Edible birds’nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is therefore considered a sustainable means of production,whereas the expansion of other agricultural activities often relies on the degradation of natural resources.This study examines the relationship between natural resources and agricultural livelihoods,focusing on Indonesian EBN farmers.Using survey data that we collected in 2017,combined with satellite information on the extent of the forest in Central Kalimantan,Indonesia,we measured production efficiency and identified the natural and social factors that enhance production performance.The results show that a forest extent ranging between 2,000 and 6,000 meters from nesting building is positively associated with the production efficiency of EBN farming,perhaps because extensive forest could help swiftlets to collect food and build nests.Conversely,while EBN farming is a sustainable and profitable option,the initial costs of constructing buildings to house swiftlets may deter farmers from participating in the process.
文摘This paper studies the status of empty nest only-child families in urban China,using data about these families taken from a 2015 survey conducted by the Institute of Population and Labor Economics,Chinese Academy of Social Sciences.Factors that determine the timing of empty nest periods and their duration for only-child parents are also analyzed.The data shows that more than half of the only-child parents surveyed in 2015 lived in empty nests.Some of these parents had been empty-nesters for as many as 25 years.During the life cycle of families,the empty nest status of elderly only-child parents shows different characteristics at different stages,as the only-children begin attending universities,start to work,get married,and have children of their own.There are empty nest periods in only-child families when the only-child leaves the parents for several years and periods when the child returns home and lives with parents for years.The living arrangements of only-child parents depend mainly on changes in the life needs of their only-children.Intergenerational support is focused on meeting the needs of only-children.
基金supported by JSPS KAKENHI[Grant Number JP19H04340]
文摘Edible birds'nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is therefore considered a sustainable means of production,whereas the expansion of other agricultural activities often relies on the degradation of natural resources.This study examines the relationship between natural resources and agricultural livelihoods,focusing on Indonesian EBN farmers.Using survey data that we collected In 2017,combined with satellite information on the extent of the forest in Central Kalimantan,Indonesia,we measured production efficiency and identified the natural and social factors that enhance production performance.The results show that a forest extent ranging between2,000 and 6,000 meters from nesting building is positively associated with the production efficiency of EBN farming,perhaps because extensive forest could help swiftlets to collect food and build nests.Conversely,while EBN farming is a sustainable and profitable option,the initial costs of constructing buildings to house swiftlets may deter farmers from participating in the process.
文摘Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Botanical Garden(XTBG)and the Institute of Zoology-revealed that the assassin bug Pahabengkakia piliceps weaponizes resin from stingless bee nests to trick its prey.
文摘This review article provides a comprehensive analysis of nesting optimization algorithms in the shipbuilding industry,emphasizing their role in improving material utilization,minimizing waste,and enhancing production efficiency.The shipbuilding process involves the complex cutting and arrangement of steel plates,making the optimization of these operations vital for cost-effectiveness and sustainability.Nesting algorithms are broadly classified into four categories:exact,heuristic,metaheuristic,and hybrid.Exact algorithms ensure optimal solutions but are computationally demanding.In contrast,heuristic algorithms deliver quicker results using practical rules,although they may not consistently achieve optimal outcomes.Metaheuristic algorithms combine multiple heuristics to effectively explore solution spaces,striking a balance between solution quality and computational efficiency.Hybrid algorithms integrate the strengths of different approaches to further enhance performance.This review systematically assesses these algorithms using criteria such as material dimensions,part geometry,component layout,and computational efficiency.The findings highlight the significant potential of advanced nesting techniques to improve material utilization,reduce production costs,and promote sustainable practices in shipbuilding.By adopting suitable nesting solutions,shipbuilders can achieve greater efficiency,optimized resource management,and superior overall performance.Future research directions should focus on integrating machine learning and real-time adaptability to further enhance nesting algorithms,paving the way for smarter,more sustainable manufacturing practices in the shipbuilding industry.
