Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and incre...Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and increased greenhouse gas emissions.In response to the current lack of studies combining drought conditions and soil erosion processes,in this study,we developed a comprehensive Geographic Information System(GIS)-based approach to assess soil erosion and droughts,thereby revealing the relationship between soil erosion and droughts under an arid climate.The vegetation condition index(VCI)and temperature condition index(TCI)derived respectively from the enhanced vegetation index(EVI)MOD13A2 and land surface temperature(LST)MOD11A2 products were combined to generate the vegetation health index(VHI).The VHI has been conceived as an efficient tool to monitor droughts in the Negueb watershed,southeastern Tunisia.The revised universal soil loss equation(RUSLE)model was applied to quantitatively estimate soil erosion.The relationship between soil erosion and droughts was investigated through Pearson correlation.Results exhibited that the Negueb watershed experienced recurrent mild to extreme drought during 2000–2016.The average soil erosion rate was determined to be 1.8 t/(hm2•a).The mountainous western part of the watershed was the most vulnerable not only to soil erosion but also to droughts.The slope length and steepness factor was shown to be the most significant controlling parameter driving soil erosion.The relationship between droughts and soil erosion had a positive correlation(r=0.3);however,the correlation was highly varied spatially across the watershed.Drought was linked to soil erosion in the Negueb watershed.The current study provides insight for natural disaster risk assessment,land managers,and stake-holders to apply appropriate management measures to promote sustainable development goals in fragile environments.展开更多
Field studies were conducted on a sandy soil during autumn of 2010 and 2011 in an arid region of Tunisia to investigate the effects of nitrogen and irrigation regimes with saline water on yield and water productivity ...Field studies were conducted on a sandy soil during autumn of 2010 and 2011 in an arid region of Tunisia to investigate the effects of nitrogen and irrigation regimes with saline water on yield and water productivity (WP) of potato (Solanum tuberosum L. cv. Spunta) and soil salinity. For the two years, irrigation treatments consisted in water replacements of cumulated crop evapotranspiration (ETc) at levels of 100% (I100, full irrigation), 60% (I60) and 30% (I30), when the readily available water in I100 treatment was depleted, while the nitrogen treatments (N) were 0, 100, 200, and 300 kg/ha (No, N100, N200, and N300). Results showed that soil salinity values remained lower than those of electrical conductivity of irrigation water (ECiw) and were the lowest under treatment I100 and the highest with I30 treatment. Relatively low ECe values were also observed under I60 treatment. The highest potato yields for the two years were obtained with I100 treatment. Compared to I100, significant reductions in potato yields were observed under I60 and I30 deficit irrigation treatments resulting from a reduction in tubers number/m2 and tuber weight. The water productivity (WP) was found to significantly vary among treatments, where the highest and the lowest values were observed for I30 and I100 treatments, respectively. Potato yield and WP increased with an increase in nitrogen rates. The rate of 300 kg N/ha was seen to give good yield and higher WP of potato under full (I100) and deficit (I60) irrigation treatments. However, application of N adversely affected potato yield and WP, when N level applied above 200 kg N/ha at I30. The WP was improved by N supply, but its effect decreased as the irrigation level increased. The IWP at I100, which produced the highest potato yield, was 8.5 and 9.9 kg/m3 with N300 but this increased to 11.9 and 15.6 kg/m3 at I30 with N200, in 2010 and 2011, respectively. These results suggested that potato in arid region could be cultivated with acceptable yields while saving irrigation water and reducing nitrogen supply but it was essential to exploit the interaction effect between these two parameters to maximize resource use efficiency.展开更多
Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors...Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors.This study aims to identify the various rangeland use forms and determine the types of livestock feeding system in the El Ouara rangelands of Ben guarden District in southern Tunisia by analysing the importance of supplemental feeding and main determinants of this practice.Data were collected by a survey that targeted a sample of 50 breeders in the El Ouara rangelands.Descriptive statistics and binary logistic regression were used to analyse the data.The results showed that there are two types of association practiced by breeders:“Cherka”association practiced by 10.00% of breeders and cash payment association practiced by 53.00% of breeders.Then,transhumance,sedentary,and semi-urban forms are the main ways in which breeders use the rangelands.There are four livestock feeding systems in the El Ouara rangelands being used to feed livestock:natural rangeland,rangeland-based,mixed,and concentrate-based feeding systems.Supplemental feeding has become fundamental for the livestock feeding system in the El Ouara rangelands.The breeders with the largest camel size still use the natural rangeland feeding system,while the breeders who have the largest herd size practice the mixed feeding system.The logistic regression results reveal that breeder age,cereal area,herd size,migrant remittance,second activity,and agricultural development group membership can significantly impact the supplemental feeding.In summary,this study can help policy-makers plan innovative practices based on climatic change,ensure the sustainability of livestock feeding system,and make effective decisions for local development.展开更多
A strain of yeast, which can endure high osmotic pressure, is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used, I.e. Calcium alginate gel be ads and PV A gel beads. ...A strain of yeast, which can endure high osmotic pressure, is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used, I.e. Calcium alginate gel be ads and PV A gel beads. The results show that the PVA gel beads is better. The influences of osmosis and heavy metal ions on the yeast entrapped in the PVA gel beads are also studied in the experiment.展开更多
Objectives: To determine if tracheal lavage concentrations of the transcriptio n factor NF-κB, which is activated by risk factors associated with bronchopulm onary dysplasia (BPD) and induces expression of cytokines ...Objectives: To determine if tracheal lavage concentrations of the transcriptio n factor NF-κB, which is activated by risk factors associated with bronchopulm onary dysplasia (BPD) and induces expression of cytokines associated with BPD, i s related to BPD in premature infants. Design: Serial tracheal lavage samples fr om intubated premature infants were analysed for cell count and concentrations o f interleukin (IL)8 and NF-κB, corrected for dilution by secretory component concentrations. Setting: Level III university hospital neonatal intensive care un it. Patients: Thirty three intubated infants (mean (SD) birth weight 903 (258) g, median gestation 27 weeks (range 24-31)-) in the first 14 days of life. Main outcome measures: Tracheal effluent NF-κB, IL-8, and cell counts, corrected for dilution by secretory component measurement. Results: Square root transforme d NF-κB concentrations were significantly related to signs of inflammation (ce ll count, P = 0.002; IL-8, P = 0.019) and to simultaneous fraction of inspired oxygen in samples from the first 3 days of life (P = 0.512, P < 0.003). Of the 3 2 subjects with samples in the first 3 days of life, the half who either died or had BPD had higher NF-κB concentrations than those without BPD (square root c oncentration 0.097 (0.043) vs 0.062 (0.036) μg/μg protein/μg secretory compon ent, P = 0.018). Conclusions: Tracheobronchial lavage NF-κB concentrations are related to lung inflammation, oxygen exposure, and pulmonary outcome in intubat ed preterm infants. NF-κB activation may be an early critical step leading to BPD.展开更多
BACKGROUND The Asia-Pacific Colorectal Screening(APCS)score was designed with the purpose of distinguishing individuals at high risk(HR)for colorectal advanced neoplasia(AN).Traditional Chinese medicine(TCM)constituti...BACKGROUND The Asia-Pacific Colorectal Screening(APCS)score was designed with the purpose of distinguishing individuals at high risk(HR)for colorectal advanced neoplasia(AN).Traditional Chinese medicine(TCM)constitution was also linked with colorectal cancer(CRC).AIM To integrate the APCS score with TCM constitution identification as a new algorithm to screen for CRC.METHODS A cross-sectional multicenter study was carried out in three hospitals,enrolling 1430 patients who were asymptomatic and undergoing screening colonoscopy from 2022 to 2023.Patients were considered to have average risk,moderate risk,or HR with their APCS score.Odd ratios assessed the relationship between TCM constitution and disease progression.A TCM constitution risk score was created.The sensitivity and specificity of the new algorithm were calculated to evaluate diagnostic performance in detecting advanced adenoma(AA),CRC,and AN.RESULTS Of the 1430 patients,370(25.9%)were categorized as average risk,755(52.8%)as moderate risk,and 305(21.3%)as HR.Using the combined APCS score and the TCM constitution(damp-heat,qi-deficiency,yang-deficiency,phlegm-dampness,and inherited special constitution as positive)algorithm,72.2%of patients with AA and 73.7%of patients with AN were detected.Compared with the APCS score alone,the new algorithm significantly improved the sensitivity for screening AA[72.2%,95%confidence interval(CI):64.4%-80.0%vs 49.2%,95%CI:40.5%-57.9%]and AN(73.7%,95%CI:66.4%-81.1%vs 51.1%,95%CI:42.7%-59.5%).CONCLUSION The combination of APCS and TCM constitution identification questionnaires was valuable in identifying Chinese individuals who were asymptomatic for colorectal screening prioritization.展开更多
The crystal structure of the title complex was measured, in which the two zinc atoms with coordination polyhedron of distorted tetragonal pyramid (TP) are bridged by an imidazolate in the apical position of the TP for...The crystal structure of the title complex was measured, in which the two zinc atoms with coordination polyhedron of distorted tetragonal pyramid (TP) are bridged by an imidazolate in the apical position of the TP forming a dimer. The isomorphous [(trien)Cu(im)Zn(trien)](ClO4)3·H2O complex was doped in the title complex and the recorded single-crystal ESR spectra by fitting gave two sets of the principal values of g and A tensors, which were assigned to the physically distinct sites of the two magnetically equivalent molecules in the unit cell. Lattice distortion at the Cu(II) ion sites and the bonding parameters of Cu(II) ions are further calculated, and the bonding nature of Cu(II) ions is discussed.展开更多
In the present paper, we have studied the blood flow through tapered artery with a stenosis. The non-Newtonian nature of blood in small arteries is analyzed mathematically by considering the blood as Phan-Thien-Tanner...In the present paper, we have studied the blood flow through tapered artery with a stenosis. The non-Newtonian nature of blood in small arteries is analyzed mathematically by considering the blood as Phan-Thien-Tanner fluid. The representation for the blood flow is through an axially non-symmetrical but radially symmetric stenosis. Symmetry of the distribution of the wall shearing stress and resistive impedance and their growth with the developing stenosis is another important feature of our analysis. Exact solutions have been evaluated for velocity, resistance impedance, wall shear stress and shearing stress at the stenosis throat. The graphical results of different type of tapered arteries （i.e. converging tapering, diverging tapering, non-tapered artery） have been examined for different narameters of interest.展开更多
基金Chinese Academy of Sciences (CAS)The World Academy of Science (TWAS) for providing financial support
文摘Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and increased greenhouse gas emissions.In response to the current lack of studies combining drought conditions and soil erosion processes,in this study,we developed a comprehensive Geographic Information System(GIS)-based approach to assess soil erosion and droughts,thereby revealing the relationship between soil erosion and droughts under an arid climate.The vegetation condition index(VCI)and temperature condition index(TCI)derived respectively from the enhanced vegetation index(EVI)MOD13A2 and land surface temperature(LST)MOD11A2 products were combined to generate the vegetation health index(VHI).The VHI has been conceived as an efficient tool to monitor droughts in the Negueb watershed,southeastern Tunisia.The revised universal soil loss equation(RUSLE)model was applied to quantitatively estimate soil erosion.The relationship between soil erosion and droughts was investigated through Pearson correlation.Results exhibited that the Negueb watershed experienced recurrent mild to extreme drought during 2000–2016.The average soil erosion rate was determined to be 1.8 t/(hm2•a).The mountainous western part of the watershed was the most vulnerable not only to soil erosion but also to droughts.The slope length and steepness factor was shown to be the most significant controlling parameter driving soil erosion.The relationship between droughts and soil erosion had a positive correlation(r=0.3);however,the correlation was highly varied spatially across the watershed.Drought was linked to soil erosion in the Negueb watershed.The current study provides insight for natural disaster risk assessment,land managers,and stake-holders to apply appropriate management measures to promote sustainable development goals in fragile environments.
文摘Field studies were conducted on a sandy soil during autumn of 2010 and 2011 in an arid region of Tunisia to investigate the effects of nitrogen and irrigation regimes with saline water on yield and water productivity (WP) of potato (Solanum tuberosum L. cv. Spunta) and soil salinity. For the two years, irrigation treatments consisted in water replacements of cumulated crop evapotranspiration (ETc) at levels of 100% (I100, full irrigation), 60% (I60) and 30% (I30), when the readily available water in I100 treatment was depleted, while the nitrogen treatments (N) were 0, 100, 200, and 300 kg/ha (No, N100, N200, and N300). Results showed that soil salinity values remained lower than those of electrical conductivity of irrigation water (ECiw) and were the lowest under treatment I100 and the highest with I30 treatment. Relatively low ECe values were also observed under I60 treatment. The highest potato yields for the two years were obtained with I100 treatment. Compared to I100, significant reductions in potato yields were observed under I60 and I30 deficit irrigation treatments resulting from a reduction in tubers number/m2 and tuber weight. The water productivity (WP) was found to significantly vary among treatments, where the highest and the lowest values were observed for I30 and I100 treatments, respectively. Potato yield and WP increased with an increase in nitrogen rates. The rate of 300 kg N/ha was seen to give good yield and higher WP of potato under full (I100) and deficit (I60) irrigation treatments. However, application of N adversely affected potato yield and WP, when N level applied above 200 kg N/ha at I30. The WP was improved by N supply, but its effect decreased as the irrigation level increased. The IWP at I100, which produced the highest potato yield, was 8.5 and 9.9 kg/m3 with N300 but this increased to 11.9 and 15.6 kg/m3 at I30 with N200, in 2010 and 2011, respectively. These results suggested that potato in arid region could be cultivated with acceptable yields while saving irrigation water and reducing nitrogen supply but it was essential to exploit the interaction effect between these two parameters to maximize resource use efficiency.
文摘Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors.This study aims to identify the various rangeland use forms and determine the types of livestock feeding system in the El Ouara rangelands of Ben guarden District in southern Tunisia by analysing the importance of supplemental feeding and main determinants of this practice.Data were collected by a survey that targeted a sample of 50 breeders in the El Ouara rangelands.Descriptive statistics and binary logistic regression were used to analyse the data.The results showed that there are two types of association practiced by breeders:“Cherka”association practiced by 10.00% of breeders and cash payment association practiced by 53.00% of breeders.Then,transhumance,sedentary,and semi-urban forms are the main ways in which breeders use the rangelands.There are four livestock feeding systems in the El Ouara rangelands being used to feed livestock:natural rangeland,rangeland-based,mixed,and concentrate-based feeding systems.Supplemental feeding has become fundamental for the livestock feeding system in the El Ouara rangelands.The breeders with the largest camel size still use the natural rangeland feeding system,while the breeders who have the largest herd size practice the mixed feeding system.The logistic regression results reveal that breeder age,cereal area,herd size,migrant remittance,second activity,and agricultural development group membership can significantly impact the supplemental feeding.In summary,this study can help policy-makers plan innovative practices based on climatic change,ensure the sustainability of livestock feeding system,and make effective decisions for local development.
文摘A strain of yeast, which can endure high osmotic pressure, is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used, I.e. Calcium alginate gel be ads and PV A gel beads. The results show that the PVA gel beads is better. The influences of osmosis and heavy metal ions on the yeast entrapped in the PVA gel beads are also studied in the experiment.
文摘Objectives: To determine if tracheal lavage concentrations of the transcriptio n factor NF-κB, which is activated by risk factors associated with bronchopulm onary dysplasia (BPD) and induces expression of cytokines associated with BPD, i s related to BPD in premature infants. Design: Serial tracheal lavage samples fr om intubated premature infants were analysed for cell count and concentrations o f interleukin (IL)8 and NF-κB, corrected for dilution by secretory component concentrations. Setting: Level III university hospital neonatal intensive care un it. Patients: Thirty three intubated infants (mean (SD) birth weight 903 (258) g, median gestation 27 weeks (range 24-31)-) in the first 14 days of life. Main outcome measures: Tracheal effluent NF-κB, IL-8, and cell counts, corrected for dilution by secretory component measurement. Results: Square root transforme d NF-κB concentrations were significantly related to signs of inflammation (ce ll count, P = 0.002; IL-8, P = 0.019) and to simultaneous fraction of inspired oxygen in samples from the first 3 days of life (P = 0.512, P < 0.003). Of the 3 2 subjects with samples in the first 3 days of life, the half who either died or had BPD had higher NF-κB concentrations than those without BPD (square root c oncentration 0.097 (0.043) vs 0.062 (0.036) μg/μg protein/μg secretory compon ent, P = 0.018). Conclusions: Tracheobronchial lavage NF-κB concentrations are related to lung inflammation, oxygen exposure, and pulmonary outcome in intubat ed preterm infants. NF-κB activation may be an early critical step leading to BPD.
文摘BACKGROUND The Asia-Pacific Colorectal Screening(APCS)score was designed with the purpose of distinguishing individuals at high risk(HR)for colorectal advanced neoplasia(AN).Traditional Chinese medicine(TCM)constitution was also linked with colorectal cancer(CRC).AIM To integrate the APCS score with TCM constitution identification as a new algorithm to screen for CRC.METHODS A cross-sectional multicenter study was carried out in three hospitals,enrolling 1430 patients who were asymptomatic and undergoing screening colonoscopy from 2022 to 2023.Patients were considered to have average risk,moderate risk,or HR with their APCS score.Odd ratios assessed the relationship between TCM constitution and disease progression.A TCM constitution risk score was created.The sensitivity and specificity of the new algorithm were calculated to evaluate diagnostic performance in detecting advanced adenoma(AA),CRC,and AN.RESULTS Of the 1430 patients,370(25.9%)were categorized as average risk,755(52.8%)as moderate risk,and 305(21.3%)as HR.Using the combined APCS score and the TCM constitution(damp-heat,qi-deficiency,yang-deficiency,phlegm-dampness,and inherited special constitution as positive)algorithm,72.2%of patients with AA and 73.7%of patients with AN were detected.Compared with the APCS score alone,the new algorithm significantly improved the sensitivity for screening AA[72.2%,95%confidence interval(CI):64.4%-80.0%vs 49.2%,95%CI:40.5%-57.9%]and AN(73.7%,95%CI:66.4%-81.1%vs 51.1%,95%CI:42.7%-59.5%).CONCLUSION The combination of APCS and TCM constitution identification questionnaires was valuable in identifying Chinese individuals who were asymptomatic for colorectal screening prioritization.
文摘The crystal structure of the title complex was measured, in which the two zinc atoms with coordination polyhedron of distorted tetragonal pyramid (TP) are bridged by an imidazolate in the apical position of the TP forming a dimer. The isomorphous [(trien)Cu(im)Zn(trien)](ClO4)3·H2O complex was doped in the title complex and the recorded single-crystal ESR spectra by fitting gave two sets of the principal values of g and A tensors, which were assigned to the physically distinct sites of the two magnetically equivalent molecules in the unit cell. Lattice distortion at the Cu(II) ion sites and the bonding parameters of Cu(II) ions are further calculated, and the bonding nature of Cu(II) ions is discussed.
文摘In the present paper, we have studied the blood flow through tapered artery with a stenosis. The non-Newtonian nature of blood in small arteries is analyzed mathematically by considering the blood as Phan-Thien-Tanner fluid. The representation for the blood flow is through an axially non-symmetrical but radially symmetric stenosis. Symmetry of the distribution of the wall shearing stress and resistive impedance and their growth with the developing stenosis is another important feature of our analysis. Exact solutions have been evaluated for velocity, resistance impedance, wall shear stress and shearing stress at the stenosis throat. The graphical results of different type of tapered arteries （i.e. converging tapering, diverging tapering, non-tapered artery） have been examined for different narameters of interest.
