Objective: To study the effects of some common additives on the antimicrobial activities of alcohol-based hand sanitizers. Methods: The antibacterial activities of varying aqueous concentrations of ethanol and isoprop...Objective: To study the effects of some common additives on the antimicrobial activities of alcohol-based hand sanitizers. Methods: The antibacterial activities of varying aqueous concentrations of ethanol and isopropyl alcohol were tested by the agar well diffusion method. The influences of different concentrations of glycerin was similarly tested. Finally, isopropyl alcohol and benzalkonium chloride were combined in different ratios within the sate use concentrations of each, and the effects of these combinations were compared with values obtained for the two agents used alone. Statistical methods, such as student t test and one-way ANOVA were used when appropriate to evaluate the differences in activity. Results: The activities of the alcohols showed marked concentration dependence, and both showed peak activity at 85%-95% concentration range. Over the concentration range of 60%-100%, isopropyl alcohol inhibited more bacterial and fungal organisms than ethanol, though the inhibition zone diameters it produced were not statistically different from those of ethanol for organisms which were sensitive to both of them.Addition of glycerin reduced the antimicrobial activities of the isopropyl alcohol, as shown by reduction in the inhibition zone diameters produced in vitro, which may be due to reduced drug diffusion with increase in viscosity. Addition of benzalkonium to isopropyl alcohol systems improved the activity of the alcohol, but the overall activity of the combination was not superior to that seen in the use of benzalkonium alone. Conclusion: Alcohol-based hand sanitizers should not be used outside the concentration range of 85%-95% and isopropyl alcohol inhibits more bacterial and fungal organisms than ethanol for most concentrations. Inclusion of benzalkonium improves the antimicrobial spectrum and activity of isopropyl alcohol, and the combination may justifiably be used to achieve both immediate and long lasting effect. Glycerin may adversely affect the antimicrobial activities of isopropyl alcohol-based hand sanitizers and should be used with caution.展开更多
Background: Hand sanitizers are an important preventive measure to halt the spread of pathogens, which has become a huge demand during the coronavirus disease (COVID-19). Consequently, their safety and quality are top...Background: Hand sanitizers are an important preventive measure to halt the spread of pathogens, which has become a huge demand during the coronavirus disease (COVID-19). Consequently, their safety and quality are top priorities for regulatory organizations. Methods: Saudi Food & Drug Authority laboratories have analyzed numerous samples of hand sanitizers in order to ensure their safety and efficacy. Active ingredients, as well as hazardous impurities, have been checked according to the pharmacopeia. Results: In this study, we report the results of the analysis of 1409 samples, which represent the majority of products available in the Saudi Arabian market. The results showed that 196 samples (13.9%) did not meet international standards. Specifically, out of 196 failed samples, 75, 12, and 4 products contained hazardous substances such as methanol, 1-propanol, and acetaldehyde, respectively. Additionally, some failed samples contained foreign particles, were improperly labeled, or contained an inadequate concentration of alcohol. Conclusion: The substandard hand sanitizers possess a risk to the community, particularly during pandemics, and hence stringent yet dynamic regulations should be implemented.展开更多
Antimicrobial efficacy of three novel organic sanitizers, CHICO WashTM, C8C10 and CG100, was evaluated for the reduction of Escherichia coli O157:H7 during flume-washing of organic leafy greens. Organic formulations a...Antimicrobial efficacy of three novel organic sanitizers, CHICO WashTM, C8C10 and CG100, was evaluated for the reduction of Escherichia coli O157:H7 during flume-washing of organic leafy greens. Organic formulations at various concentrations: CHICO (C3H8I0C3O7) WashTM (1:20 ratio) and C8C10 and CG100 (0.2 and 0.4%), along with the controls: hydrogen-peroxide and water, were used for washing organic baby and mature spinach and romaine and iceberg lettuce. Leafy greens were inoculated with a 2-strain cocktail of E. coli O157:H7 (6 logs CFU/mL) and washed in each treatment for 1 or 2 minutes. The treated leafy greens were stored at 4°C and surviving pathogen populations determined on days 0, 1, and 3 of storage. Organic sanitizers, for both treatment times, significantly (P E. coli O157:H7 on all the leafy greens during storage. Highest reduction (3.4 logs CFU/g) was observed after treatment with CG100 (0.4%) in romaine lettuce, while CHICO WashTM showed greater than 2 logs CFU/g reduction on all the leafy greens, by day 3. This study demonstrates the potential application of organic sanitizers in flume-washing of organic leafy greens for the reduction of E. coli O157:H7.展开更多
<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>...<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>Method:</strong> a transverse study has been conducted during the period starting from 11 up to 28 October 2018 within 6 Health Zones (HZ) in Tshopo Province integrated in National Program of Schools and Sanitized Villages (NPSSV). Water samples have been collected within 300 reserves of households and 30 water provisioning and analysed points in order to find out water contamination factors. The frequencies and raw OR have been estimated at (p < 0.05) valued significative. <strong>Results:</strong> fecal coliforms (80% CI95: 75% - 85%) and total (97% CI95: 95% - 99%) were significantly present in water reserves and the presence of Escherichia coli were at about 27% (IC95 22% - 32%). These proportions were correspondingly at 63%, 90% and 10% at water provisioning. The fecal coliforms were the highest in water reserves of sanitized villages (p < 0.05) and Escherichia coli were at about three times higher in traditional sources (17% vs 6%). The duration of water conservation was around 48 hours and more (OR = 4.41;IC95: 1.92 - 10.11), water classification of sanitized risk “intermedium” and the recipients of conservation with bottleneck were associated with the presence of E.coli in water (p < 0.05). <strong>Conclusion: </strong>water from provisioning sources and household reserves are severely polluted and water quality is not good at consumption point and at provisioning point. The reinforcement of safety measures at water points, reduction of conservation length and hygienic water cleaning of storage water recipients are necessary to assure quality of water.展开更多
More than 85%of the currently marketed hand sanitizer products are alcohol-based products,and the alcohol content is usually about 70%in order to be effective.The high alcohol content can cause dehydration,which is un...More than 85%of the currently marketed hand sanitizer products are alcohol-based products,and the alcohol content is usually about 70%in order to be effective.The high alcohol content can cause dehydration,which is undesirable for sensitive skin,particularly for children.This creates opportunities for the development of innovative hand sanitizer products that are free of alcohol and have green nano-cellulose-based materials as carriers for the antibacterial agents.Good skin affinity and biocompatibility are the special features of the newly developed products,which would satisfy the need of the general public for green products.展开更多
The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack o...The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack of sanitation facilities.The project,targeting 14,082 households,started last year.展开更多
This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season....This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season.Swab samples from used berry lugs(UL),cleaned/sanitized lugs(CL),used handpicking buckets(UB),and cleaned/sanitized buckets(CB)in Georgia(n=160)and from used berry flats(UF)and cleaned/sanitized flats(CF)as well as UB and CB in Oregon(n=160)were collected.The populations of total aerobes(TA),total yeasts and molds(YM),and total coliforms(TC),as well as the incidences of fecal coliforms(FC),and enterococci(EC)were determined.In Georgia,the UL and UB had significantly(P<0.05)higher TA and YM counts than their cleaned/sanitized counterparts.FC and EC were detected in 1.3%or 3.8%of the samples.In Oregon,UB had significantly higher mean YM and TC counts than CB.FC and EC were detected in 3.8%or 10.6%of the samples.Containers soaked in chlorinated water with manual washing/scrubbing seemed cleaner than those washed in a washing machine with un-chlorinated water.Chlorination of water in the washing machine after each use was,nevertheless,more effective than manual washing.展开更多
■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.T...■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.Their research questions the reliability of traditional fecal indicators and highlights a core issue in environmental health:invisible,routine exposure pathways that are difficult to capture with standard tools.展开更多
Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds res...Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds resulting in a lower amount of chlorine available for disinfection. Another concern is that some forms of chlorine can react with some organic compounds to form toxic halogenated disinfection byproducts（DBPs）. Many studies have been conducted to evaluate the role of hypochlorous acid（HOCl） and hypochlorite ion（OCl–） in the production of DBPs with a particular interest in the production of trihalomethanes（THMs） and haloacetic acids（HAAs）. Since most of the chlorine reactions are pH dependent, pH is found to have a significant effect on the formation of chlorine DBPs. In many cases, the concentration of THMs decreases and HAAs increases as pH decreases. pH also plays an important role in the determination of the type and amount of DBPs formed, with lower, more acidic, pHs resulting in the formation of less chloroform. This review summarizes the information from the literature on the role of chlorine-based sanitizers as affected by pH in the formation of different types of DBPs. Alternative novel strategies to minimize the formation of DBPs are also discussed.展开更多
Piroctone olamine(OCT) was used as the main bacteriostatic component, the inhibition of OCT in different kinds and mass concentrations of surfactants were studied. Six surfactants commonly used in personal care produc...Piroctone olamine(OCT) was used as the main bacteriostatic component, the inhibition of OCT in different kinds and mass concentrations of surfactants were studied. Six surfactants commonly used in personal care products, i.e. sodium laureth sulfate(AES), cocamidopropyl betaine(CAB 35), sodium lauroyl sarcosinate(LS-30), sodium lauroyl glutamate(ULS-30S), alkyl glycoside(APG), cocamide methyl MEA(CMMEA),were used. The results showed that the bacteriostatic of OCT decreased with the increase of AES, which was suggested ≤ 5%. OCT has good bacteriostatic performance in the systems of amino acid surfactants and high dosage of amphoteric surfactants, 5% LS 30 and ≥ 10% CAB 35 was recommended. High dosage of nonionic surfactant could interfere the bacteriostatic performance of OCT, the recommended dosage was ≤ 2%.In addition, OCT has good bacteriostatic performance against Staphylococcus aureus, Escherichia coli and Candida albicans when pH was controlled less than 5.5.展开更多
Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasiti...Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasitic eggs is a specific anti-parasitic behavior. Previous studies have shown that egg recognition may have evolved from nest sanitation behavior;however, few studies have offered evidence in support of this hypothesis. In the current study, we added one real white egg and one model egg to the nests of common tailorbirds (Orthotomus sutorius), the main host of plaintive cuckoos (Cacomantis merulinus), to explore the relationship between egg recognition ability in hosts and nest sanitation behavior. Results showed that common tailorbirds rejected both non-mimetic blue model eggs and mimetic white model eggs at a similar rate of 100%, but only rejected 16.1% of mimetic real white eggs. The egg rejection behavior of common tailorbirds towards both real and model eggs was consistent. However, when both blue model eggs and real white eggs were simultaneously added to their nests, the probability of rejecting the mimetic real white egg increased to 50%. The addition of blue model eggs not only increased the occurrence of nest sanitation behavior but also increased the ability to recognize and reject parasitic eggs. This suggests that nest sanitation may facilitate egg rejection in common tailorbird hosts.展开更多
Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences....Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.展开更多
Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂...Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂ that includes separation of the black water from water system by a non-flushing toilet （bio-toilet）, and a gray water treatment based on a biological and ecological concept. Sustainable sanitation system also converts the domestic waste to soil conditioners and fertilizers, for farmland use. As one of the case studies, Environmentally Symbiotic Housing in which people actually live using the bio-toilet for the black water treatment and the household wastewater treatment facility for the gray water was introduced. The availability of this system was investigated by analyzing the sawdust used in the bio-toilet and the quality of the effluent in the household wastewater treatment facility. As the result, the water content of the sawdust did not exceed 60% in any of the sampling points and the BOD and COD of the effluent of the household wastewater treatment facility were below 10 and 20 mg/L respectively, due to the low loading. Compared to the pollution load on the water environment created by the conventional system, it was found that the effluent of the house has a lower load than the tertiary treatment and the volume of the water consumption is 75% of the conventional system.展开更多
文摘Objective: To study the effects of some common additives on the antimicrobial activities of alcohol-based hand sanitizers. Methods: The antibacterial activities of varying aqueous concentrations of ethanol and isopropyl alcohol were tested by the agar well diffusion method. The influences of different concentrations of glycerin was similarly tested. Finally, isopropyl alcohol and benzalkonium chloride were combined in different ratios within the sate use concentrations of each, and the effects of these combinations were compared with values obtained for the two agents used alone. Statistical methods, such as student t test and one-way ANOVA were used when appropriate to evaluate the differences in activity. Results: The activities of the alcohols showed marked concentration dependence, and both showed peak activity at 85%-95% concentration range. Over the concentration range of 60%-100%, isopropyl alcohol inhibited more bacterial and fungal organisms than ethanol, though the inhibition zone diameters it produced were not statistically different from those of ethanol for organisms which were sensitive to both of them.Addition of glycerin reduced the antimicrobial activities of the isopropyl alcohol, as shown by reduction in the inhibition zone diameters produced in vitro, which may be due to reduced drug diffusion with increase in viscosity. Addition of benzalkonium to isopropyl alcohol systems improved the activity of the alcohol, but the overall activity of the combination was not superior to that seen in the use of benzalkonium alone. Conclusion: Alcohol-based hand sanitizers should not be used outside the concentration range of 85%-95% and isopropyl alcohol inhibits more bacterial and fungal organisms than ethanol for most concentrations. Inclusion of benzalkonium improves the antimicrobial spectrum and activity of isopropyl alcohol, and the combination may justifiably be used to achieve both immediate and long lasting effect. Glycerin may adversely affect the antimicrobial activities of isopropyl alcohol-based hand sanitizers and should be used with caution.
文摘Background: Hand sanitizers are an important preventive measure to halt the spread of pathogens, which has become a huge demand during the coronavirus disease (COVID-19). Consequently, their safety and quality are top priorities for regulatory organizations. Methods: Saudi Food & Drug Authority laboratories have analyzed numerous samples of hand sanitizers in order to ensure their safety and efficacy. Active ingredients, as well as hazardous impurities, have been checked according to the pharmacopeia. Results: In this study, we report the results of the analysis of 1409 samples, which represent the majority of products available in the Saudi Arabian market. The results showed that 196 samples (13.9%) did not meet international standards. Specifically, out of 196 failed samples, 75, 12, and 4 products contained hazardous substances such as methanol, 1-propanol, and acetaldehyde, respectively. Additionally, some failed samples contained foreign particles, were improperly labeled, or contained an inadequate concentration of alcohol. Conclusion: The substandard hand sanitizers possess a risk to the community, particularly during pandemics, and hence stringent yet dynamic regulations should be implemented.
文摘Antimicrobial efficacy of three novel organic sanitizers, CHICO WashTM, C8C10 and CG100, was evaluated for the reduction of Escherichia coli O157:H7 during flume-washing of organic leafy greens. Organic formulations at various concentrations: CHICO (C3H8I0C3O7) WashTM (1:20 ratio) and C8C10 and CG100 (0.2 and 0.4%), along with the controls: hydrogen-peroxide and water, were used for washing organic baby and mature spinach and romaine and iceberg lettuce. Leafy greens were inoculated with a 2-strain cocktail of E. coli O157:H7 (6 logs CFU/mL) and washed in each treatment for 1 or 2 minutes. The treated leafy greens were stored at 4°C and surviving pathogen populations determined on days 0, 1, and 3 of storage. Organic sanitizers, for both treatment times, significantly (P E. coli O157:H7 on all the leafy greens during storage. Highest reduction (3.4 logs CFU/g) was observed after treatment with CG100 (0.4%) in romaine lettuce, while CHICO WashTM showed greater than 2 logs CFU/g reduction on all the leafy greens, by day 3. This study demonstrates the potential application of organic sanitizers in flume-washing of organic leafy greens for the reduction of E. coli O157:H7.
文摘<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>Method:</strong> a transverse study has been conducted during the period starting from 11 up to 28 October 2018 within 6 Health Zones (HZ) in Tshopo Province integrated in National Program of Schools and Sanitized Villages (NPSSV). Water samples have been collected within 300 reserves of households and 30 water provisioning and analysed points in order to find out water contamination factors. The frequencies and raw OR have been estimated at (p < 0.05) valued significative. <strong>Results:</strong> fecal coliforms (80% CI95: 75% - 85%) and total (97% CI95: 95% - 99%) were significantly present in water reserves and the presence of Escherichia coli were at about 27% (IC95 22% - 32%). These proportions were correspondingly at 63%, 90% and 10% at water provisioning. The fecal coliforms were the highest in water reserves of sanitized villages (p < 0.05) and Escherichia coli were at about three times higher in traditional sources (17% vs 6%). The duration of water conservation was around 48 hours and more (OR = 4.41;IC95: 1.92 - 10.11), water classification of sanitized risk “intermedium” and the recipients of conservation with bottleneck were associated with the presence of E.coli in water (p < 0.05). <strong>Conclusion: </strong>water from provisioning sources and household reserves are severely polluted and water quality is not good at consumption point and at provisioning point. The reinforcement of safety measures at water points, reduction of conservation length and hygienic water cleaning of storage water recipients are necessary to assure quality of water.
基金the National Natural Science Foundation of China(31501440)China Postdoctoral Science Foundation(2015M571269)+1 种基金Tianjin Science and Technology Commissioner Program(16JCTPJC45300)Tianjin International Training Program for Excellent Postdoctoral Fellows of 2015.
文摘More than 85%of the currently marketed hand sanitizer products are alcohol-based products,and the alcohol content is usually about 70%in order to be effective.The high alcohol content can cause dehydration,which is undesirable for sensitive skin,particularly for children.This creates opportunities for the development of innovative hand sanitizer products that are free of alcohol and have green nano-cellulose-based materials as carriers for the antibacterial agents.Good skin affinity and biocompatibility are the special features of the newly developed products,which would satisfy the need of the general public for green products.
文摘The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack of sanitation facilities.The project,targeting 14,082 households,started last year.
文摘This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season.Swab samples from used berry lugs(UL),cleaned/sanitized lugs(CL),used handpicking buckets(UB),and cleaned/sanitized buckets(CB)in Georgia(n=160)and from used berry flats(UF)and cleaned/sanitized flats(CF)as well as UB and CB in Oregon(n=160)were collected.The populations of total aerobes(TA),total yeasts and molds(YM),and total coliforms(TC),as well as the incidences of fecal coliforms(FC),and enterococci(EC)were determined.In Georgia,the UL and UB had significantly(P<0.05)higher TA and YM counts than their cleaned/sanitized counterparts.FC and EC were detected in 1.3%or 3.8%of the samples.In Oregon,UB had significantly higher mean YM and TC counts than CB.FC and EC were detected in 3.8%or 10.6%of the samples.Containers soaked in chlorinated water with manual washing/scrubbing seemed cleaner than those washed in a washing machine with un-chlorinated water.Chlorination of water in the washing machine after each use was,nevertheless,more effective than manual washing.
文摘■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.Their research questions the reliability of traditional fecal indicators and highlights a core issue in environmental health:invisible,routine exposure pathways that are difficult to capture with standard tools.
文摘Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds resulting in a lower amount of chlorine available for disinfection. Another concern is that some forms of chlorine can react with some organic compounds to form toxic halogenated disinfection byproducts（DBPs）. Many studies have been conducted to evaluate the role of hypochlorous acid（HOCl） and hypochlorite ion（OCl–） in the production of DBPs with a particular interest in the production of trihalomethanes（THMs） and haloacetic acids（HAAs）. Since most of the chlorine reactions are pH dependent, pH is found to have a significant effect on the formation of chlorine DBPs. In many cases, the concentration of THMs decreases and HAAs increases as pH decreases. pH also plays an important role in the determination of the type and amount of DBPs formed, with lower, more acidic, pHs resulting in the formation of less chloroform. This review summarizes the information from the literature on the role of chlorine-based sanitizers as affected by pH in the formation of different types of DBPs. Alternative novel strategies to minimize the formation of DBPs are also discussed.
文摘Piroctone olamine(OCT) was used as the main bacteriostatic component, the inhibition of OCT in different kinds and mass concentrations of surfactants were studied. Six surfactants commonly used in personal care products, i.e. sodium laureth sulfate(AES), cocamidopropyl betaine(CAB 35), sodium lauroyl sarcosinate(LS-30), sodium lauroyl glutamate(ULS-30S), alkyl glycoside(APG), cocamide methyl MEA(CMMEA),were used. The results showed that the bacteriostatic of OCT decreased with the increase of AES, which was suggested ≤ 5%. OCT has good bacteriostatic performance in the systems of amino acid surfactants and high dosage of amphoteric surfactants, 5% LS 30 and ≥ 10% CAB 35 was recommended. High dosage of nonionic surfactant could interfere the bacteriostatic performance of OCT, the recommended dosage was ≤ 2%.In addition, OCT has good bacteriostatic performance against Staphylococcus aureus, Escherichia coli and Candida albicans when pH was controlled less than 5.5.
基金supported by the National Natural Science Foundation of China(31672303 to C.C.Y.,and 31472013,31772453 and 31970427 to W.L.)
文摘Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasitic eggs is a specific anti-parasitic behavior. Previous studies have shown that egg recognition may have evolved from nest sanitation behavior;however, few studies have offered evidence in support of this hypothesis. In the current study, we added one real white egg and one model egg to the nests of common tailorbirds (Orthotomus sutorius), the main host of plaintive cuckoos (Cacomantis merulinus), to explore the relationship between egg recognition ability in hosts and nest sanitation behavior. Results showed that common tailorbirds rejected both non-mimetic blue model eggs and mimetic white model eggs at a similar rate of 100%, but only rejected 16.1% of mimetic real white eggs. The egg rejection behavior of common tailorbirds towards both real and model eggs was consistent. However, when both blue model eggs and real white eggs were simultaneously added to their nests, the probability of rejecting the mimetic real white egg increased to 50%. The addition of blue model eggs not only increased the occurrence of nest sanitation behavior but also increased the ability to recognize and reject parasitic eggs. This suggests that nest sanitation may facilitate egg rejection in common tailorbird hosts.
基金supported by the National Natural Science Foundation of China (No.31970427 and 32270526 to WL)supported by the specific research fund of The Innovation Platform for Academicians of Hainan Province
文摘Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.
文摘Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂ that includes separation of the black water from water system by a non-flushing toilet （bio-toilet）, and a gray water treatment based on a biological and ecological concept. Sustainable sanitation system also converts the domestic waste to soil conditioners and fertilizers, for farmland use. As one of the case studies, Environmentally Symbiotic Housing in which people actually live using the bio-toilet for the black water treatment and the household wastewater treatment facility for the gray water was introduced. The availability of this system was investigated by analyzing the sawdust used in the bio-toilet and the quality of the effluent in the household wastewater treatment facility. As the result, the water content of the sawdust did not exceed 60% in any of the sampling points and the BOD and COD of the effluent of the household wastewater treatment facility were below 10 and 20 mg/L respectively, due to the low loading. Compared to the pollution load on the water environment created by the conventional system, it was found that the effluent of the house has a lower load than the tertiary treatment and the volume of the water consumption is 75% of the conventional system.
