Seeds of many hardwood trees are dispersed by scatter-hoarding rodents,and this process is often mediated by the traits of seeds.Although numerous studies have linked seed traits to seed preference by rodents,little i...Seeds of many hardwood trees are dispersed by scatter-hoarding rodents,and this process is often mediated by the traits of seeds.Although numerous studies have linked seed traits to seed preference by rodents,little is known about how rodents forage for seeds when multiple desirable and undesirable seed traits are available simultaneously.Here,we adopt a novel method of designing choice experiments to study how eastern gray squirrels(Sciurus carolinensis)select for 6 traits(caloric value,protein content,tannin concentration,kernel mass,dormancy period and toughness of shell)among seeds.From n=426 seed-pair presentations,we found that squirrels preferentially consumed seeds with short dormancy or tougher shells,and preferentially cached seeds with larger kernel mass,tougher shells and higher tannin concentrations.By incorporating random effects,we found that squirrels exhibited consistent preferences for seed traits,which is likely due to the fitness consequences associated with maintaining cached resources.Furthermore,we found that squirrels were willing to trade between multiple traits when caching seeds,which likely results in more seed species being cached in the fall.Ultimately,our approach allowed us to compute the relative values of different seed traits to squirrels,despite covariance among studied traits across seed species.In addition,by investigating how squirrels trade among different seed traits,important insights can be gleaned into behavioral mechanisms underlying seed caching(and,thus,seed survival)dynamics as well as evolutionary strategies adopted by plants to attract seed dispersers.We describe how discrete choice experiments can be used to study resource selection in other ecological systems.展开更多
BACKGROUND Patients with Crohn’s disease(CD)are at risk of developing complications such as perianal fistulas.Patients with Crohn’s perianal fistulas(CPF)are affected by fecal incontinence(FI),bleeding,pain,swelling...BACKGROUND Patients with Crohn’s disease(CD)are at risk of developing complications such as perianal fistulas.Patients with Crohn’s perianal fistulas(CPF)are affected by fecal incontinence(FI),bleeding,pain,swelling,and purulent perianal discharge,and METHODS This cross-sectional observational study was conducted in patients with CD aged 21-90 years via a web-enabled questionnaire in seven countries(April-August 2021).Patients were recruited into three cohorts:Cohort 1 included patients without perianal fistulas;cohort 2 included patients with perianal fistulas without fistula-related surgery;and cohort 3 included patients with perianal fistulas and fistula-related surgery.Validated patient-reported outcome measures were used to assess quality of life.Drivers of treatment preferences were measured using a discrete choice experiment(DCE).RESULTS In total,929 patients were recruited(cohort 1,n=620;cohort 2,n=174;cohort 3,n=135).Short Inflammatory Bowel Disease Questionnaire scores were worse for patients with CPF(cohorts 2 and 3)than for those with CD without CPF(cohort 1):Mean score 3.8 and 3.7 vs 4.1,respectively,(P<0.001).Similarly,mean Revised FI and FI Quality of Life scores were worse for patients with CPF than for those with CD without CPF.Quality of Life with Anal Fistula scores were similar in patients with CPF with or without CPF-related surgery(cohorts 2 and 3):Mean score 41 and 42,respectively.In the DCE,postoperative discomfort and fistula healing rate were the most important treatment attributes influencing treatment choice:Mean relative importance 35.7 and 24.7,respectively.CONCLUSION The burden of illness in CD is significantly higher for patients with CPF and patients rate lower postoperative discomfort and higher healing rates as the most desirable treatment attributes.展开更多
Understanding the heterogeneous preferences of individuals for disaster insurance attributes is critical for product improvement and policy design.In an era of global environmental change,the Qinghai-Tibet Plateau is ...Understanding the heterogeneous preferences of individuals for disaster insurance attributes is critical for product improvement and policy design.In an era of global environmental change,the Qinghai-Tibet Plateau is a hotspot of natural hazards.Improving the capability of rural housing disaster insurance to foster local residents’disaster resilience is of great signifcance but remains under addressed.We used a discrete choice experiment approach to provide the frst estimates of rural residents’preferences for rural housing disaster insurance attributes in central and western Tibet.We estimated residents’preferences and willingness-to-pay for the sum insured,subsidy rate,insured object,and perils covered.The potential impacts of increasing the sum insured,expanding the insured object,and lowering subsidy rates were evaluated.Our results suggest that residents prefer products with a high sum insured,high subsidy rate,and a complete list of insured objects.Residents who have experienced specifc hazards tend to prefer the corresponding perils covered.Females and residents who have a closer social network are more likely to purchase insurance.Product improvement and policy simulation results suggest that,while lowering the subsidy rate,increasing the sum insured and expanding the insured object could promote participation and improve residents’welfare.Our results could improve the understanding of the preferences of households in remote regions and support policy implementations.展开更多
基金The Fred M.Van Eck Forest Foundation for Purdue University and the McIntire-Stennis program provided funding.
文摘Seeds of many hardwood trees are dispersed by scatter-hoarding rodents,and this process is often mediated by the traits of seeds.Although numerous studies have linked seed traits to seed preference by rodents,little is known about how rodents forage for seeds when multiple desirable and undesirable seed traits are available simultaneously.Here,we adopt a novel method of designing choice experiments to study how eastern gray squirrels(Sciurus carolinensis)select for 6 traits(caloric value,protein content,tannin concentration,kernel mass,dormancy period and toughness of shell)among seeds.From n=426 seed-pair presentations,we found that squirrels preferentially consumed seeds with short dormancy or tougher shells,and preferentially cached seeds with larger kernel mass,tougher shells and higher tannin concentrations.By incorporating random effects,we found that squirrels exhibited consistent preferences for seed traits,which is likely due to the fitness consequences associated with maintaining cached resources.Furthermore,we found that squirrels were willing to trade between multiple traits when caching seeds,which likely results in more seed species being cached in the fall.Ultimately,our approach allowed us to compute the relative values of different seed traits to squirrels,despite covariance among studied traits across seed species.In addition,by investigating how squirrels trade among different seed traits,important insights can be gleaned into behavioral mechanisms underlying seed caching(and,thus,seed survival)dynamics as well as evolutionary strategies adopted by plants to attract seed dispersers.We describe how discrete choice experiments can be used to study resource selection in other ecological systems.
文摘BACKGROUND Patients with Crohn’s disease(CD)are at risk of developing complications such as perianal fistulas.Patients with Crohn’s perianal fistulas(CPF)are affected by fecal incontinence(FI),bleeding,pain,swelling,and purulent perianal discharge,and METHODS This cross-sectional observational study was conducted in patients with CD aged 21-90 years via a web-enabled questionnaire in seven countries(April-August 2021).Patients were recruited into three cohorts:Cohort 1 included patients without perianal fistulas;cohort 2 included patients with perianal fistulas without fistula-related surgery;and cohort 3 included patients with perianal fistulas and fistula-related surgery.Validated patient-reported outcome measures were used to assess quality of life.Drivers of treatment preferences were measured using a discrete choice experiment(DCE).RESULTS In total,929 patients were recruited(cohort 1,n=620;cohort 2,n=174;cohort 3,n=135).Short Inflammatory Bowel Disease Questionnaire scores were worse for patients with CPF(cohorts 2 and 3)than for those with CD without CPF(cohort 1):Mean score 3.8 and 3.7 vs 4.1,respectively,(P<0.001).Similarly,mean Revised FI and FI Quality of Life scores were worse for patients with CPF than for those with CD without CPF.Quality of Life with Anal Fistula scores were similar in patients with CPF with or without CPF-related surgery(cohorts 2 and 3):Mean score 41 and 42,respectively.In the DCE,postoperative discomfort and fistula healing rate were the most important treatment attributes influencing treatment choice:Mean relative importance 35.7 and 24.7,respectively.CONCLUSION The burden of illness in CD is significantly higher for patients with CPF and patients rate lower postoperative discomfort and higher healing rates as the most desirable treatment attributes.
基金supported by the Second Tibetan Plateau Scientifc Expedition and Research Program(STEP No.2019QZKK0906)the joint project of National Natural Science Foundation of China(NSFC)and Bill Melinda Gates Foundation(BMGF)under Grant No.72261147759。
文摘Understanding the heterogeneous preferences of individuals for disaster insurance attributes is critical for product improvement and policy design.In an era of global environmental change,the Qinghai-Tibet Plateau is a hotspot of natural hazards.Improving the capability of rural housing disaster insurance to foster local residents’disaster resilience is of great signifcance but remains under addressed.We used a discrete choice experiment approach to provide the frst estimates of rural residents’preferences for rural housing disaster insurance attributes in central and western Tibet.We estimated residents’preferences and willingness-to-pay for the sum insured,subsidy rate,insured object,and perils covered.The potential impacts of increasing the sum insured,expanding the insured object,and lowering subsidy rates were evaluated.Our results suggest that residents prefer products with a high sum insured,high subsidy rate,and a complete list of insured objects.Residents who have experienced specifc hazards tend to prefer the corresponding perils covered.Females and residents who have a closer social network are more likely to purchase insurance.Product improvement and policy simulation results suggest that,while lowering the subsidy rate,increasing the sum insured and expanding the insured object could promote participation and improve residents’welfare.Our results could improve the understanding of the preferences of households in remote regions and support policy implementations.
