The scientific community faces the challenge of measuring progress toward biodiversity targets and indices have been traditionally used.However,recent inventories in secondary tropical mountain forests using tradition...The scientific community faces the challenge of measuring progress toward biodiversity targets and indices have been traditionally used.However,recent inventories in secondary tropical mountain forests using traditional biodiversity indices have yielded results that are indistinct with primary ones.This shows the need to develop complementary indices that goes beyond species count but integrates the distribution and conservation status of the species.This study developed endemicity and conservation importance index for tropical forest that incorporated the distribution and conservation status of the species.These indices were applied to Mt.Natoo,a remnant primary mossy forest in Buguias,Benguet,Philippines,that resulted to endemicity index of 81.07 and conservation importance index of 42.90.Comparing these with secondary forest sites with comparable Shannon-Wiener,Simpson,Evenness and Margalef’s indices,our endemicity and conservation indices clearly differentiates primary forest(our study site)with higher values from secondary forests with much lower values.Thus,we are proposing these indices for a direct but scientifically-informed identification of specific sites for conservation and protection in tropical forests.Additionally,our study documented a total of 168 vascular plant species(79 endemic and 12 locally threatened species)in Mt.Nato-o.Majority are of tropical elements for both generic and species levels with some temperate elements that could be attributed to the site's high elevation and semi-temperate climate.These are important baseline information for conservation plans and monitoring of tropical mossy forests.展开更多
Mosquito-borne infections are of global health concern because of their rapid spread and upsurge,which creates a risk for coinfections.chikungunya virus(CHIKV),an arbovirus disease transmitted by Aedes aegypti or A.al...Mosquito-borne infections are of global health concern because of their rapid spread and upsurge,which creates a risk for coinfections.chikungunya virus(CHIKV),an arbovirus disease transmitted by Aedes aegypti or A.albopictus,and malaria,a parasitic disease transmitted by Anopheles gambiae,are prevalent in Nigeria and neighbouring countries,but their burden and possible coinfections are poorly understood.In this study,we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses(ZIKV)in three regions of Nigeria.A cross-sectional serosurvey was conducted on 871 participants.Samples were collected from outpatients by simple random sampling.Analyses of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP(virus like particle),ZIKV NS1 and ZIKV Equad according to manufacturers’instructions and malaria RDT for malaria parasite.There was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions(69.5%,291/419),while ZIKV-seropositivity(22.4%,34/152)and CHIKV-ZIKV co-circulating antibody seropositivity(17.8%,27/152)were notably higher in the southern region than in the central and northern regions.This investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian regions.The seropositivity of detectable antibodies differed among the three geographical locations.展开更多
We are currently faced with the question of how the CoV-2 severity may change in the years ahead.Our analysis of immunological and epidemiological data on endemic human coronaviruses(HCoVs)shows that infection-blockin...We are currently faced with the question of how the CoV-2 severity may change in the years ahead.Our analysis of immunological and epidemiological data on endemic human coronaviruses(HCoVs)shows that infection-blocking immunity wanes rapidly,but disease-reducing immunity is long-lived.Our model,incorporating these components of immunity,recapitulates both the current severity of CoV-2 and the benign nature of HCoVs,suggesting that once the endemic phase is reached and primary exposure is in childhood,CoV-2 may be no more virulent than the common cold.展开更多
[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
Objective Cholera caused by Vibrio cholerae biotype eltor (EVC) is an endemic disease, subsiding in winter and reappearing in spring and summer Investigating the state of EVC during the intermittent time is of ...Objective Cholera caused by Vibrio cholerae biotype eltor (EVC) is an endemic disease, subsiding in winter and reappearing in spring and summer Investigating the state of EVC during the intermittent time is of crucial importance in controlling this disease Methods Different factors mimicking the internal and external environmental conditions of the host, including human and fish bile, bacterial phages and antibiotics were used experimentally to induce variation in EVC EVC variants were isolated from the stool of diarrhea patients and river water in old endemic areas during the winter The variants obtained were tested with gene probe hybridization, DNA restriction enzyme mapping, immunoenzyme staining and animal passaging Results Due to the loss of cell walls, 3 kinds of EVC variants were obtained during induction: the L form variant, with a complete loss of cell walls; the nonagglutinating variants, with the loss of surface O antigen; the phage resistant variants, with the loss of phage receptors Similar variants were found in field isolation This variation was proved to be phenotypic, with no change in genetic material: it was reversible and appeared in a seasonal pattern, which coincided with the endemicity of this disease Passage in animal enhanced this reversion In compensation for the loss of cell walls, cell membranes were greatly thickened, increasing the ability of the variants to survive during the unfavorable winter conditions Conclusions EVC varied in a seasonal pattern, coincident with the endemicity of this disease The compensatory thickening of the cell membranes protects the EVC variants to survive the winter展开更多
Salt stress might be an important factor that decreases the emergence of seedlings and reduces plants'growth,causing their endangered status.However,the effects of salt stress on the germination of the Mediterrane...Salt stress might be an important factor that decreases the emergence of seedlings and reduces plants'growth,causing their endangered status.However,the effects of salt stress on the germination of the Mediterranean species are less concern.Limonium strictissimum(Salzm.)Arrigoni,part of the group related to Limonium articulatum(Loisel.)Kuntze,is a Cyrno-Sardinian endemism,which is included in the International Union for Conservation of Nature(IUCN)Red Lists as Endangered(EN).Fresh seeds of L.strictissimum harvested from the only known population in Sardinia and a population in southeastern Corsica were used with the aims to study the effects of temperature and salinity on the seed germination and to evaluate the ability to recover their germination after exposure to salt stress.In both populations,empty fruits with a lower percentage were observed in Sardinia than in Corsica.The seeds showed a high germination capacity,which was not influenced by temperature and did not even differ between the two populations.Compared with non-saline condition,the presence of salt in the substrate,independently of the concentration tested,inhibited seed germination in both populations,with germination percentages never exceeding 40%.The Sardinian population showed a recovery capacity after exposure to high salt stress,always above 50%regardless of the salt concentration and incubation temperature considered.The seeds previously exposed to 125 mM NaCl at 30℃ had the lowest recovery percentage(56%),while the highest recovery percentage(84%)was recorded at 25℃ with a concentration of 250 mM NaCl.Differently,the Corsican population recorded a higher recovery percentage(54%)in seeds previously exposed to 500 mM NaCl at 20℃,while for the concentration of 125 mM NaCl,the best recovery percentage(11%)was recorded at 30℃.The ability of L.strictissimum to recover germination after salt exposure can be interpreted as an adaptation to the coastal habitats in which it grows.This study provides new insights into the ecophysiology of L.strictissimum seed germination,which could help preserve and implement effective conservation measures for this endangered species with restricted populations.展开更多
Gebel Katrina,located in the Saint Catherine Protectorate of South Sinai(Egypt),is a biologically rich area with diverse plant communities shaped by factors such as elevation,slope,soil type,and precipitation.This stu...Gebel Katrina,located in the Saint Catherine Protectorate of South Sinai(Egypt),is a biologically rich area with diverse plant communities shaped by factors such as elevation,slope,soil type,and precipitation.This study was designed to examine the vegetation structure,update the occurrence of endemic taxa,and investigate the impact of environmental conditions and landform types on plant disruption in the region.The primary objective of this study was to analyze the behavior and distribution of the most common species across major environmental gradients.Between 2022 and 2024,49 stands were randomly collected within the study area characterized by relatively uniform vegetation and physiography and represent as much as possible the four major landform types(terraces,slopes,ridges,and gorges).The selected stands were distributed as follows:terraces(12 stands),slopes(9 stands),ridges(9 stands),and gorges(19 stands).For the analysis of the biological spectrum,a growth-form system with four categories was utilized:trees(T),shrubs(S),perennial herbs(PH),and annual herbs(A).Soil analyses were conducted for composite samples from the 49 stands.For each recorded species,nativity,species diversity measurements,endemism,and IUCN conservation status were depicted.Multivariate analysis techniques were used to assess the classification of the 49 stands in various landforms,and ordination with soil variables were applied using different software.A total of 137 taxa were recorded from Gebel Katrina area belonging to 39 families(1 Pteridaceae,1 Ephedraceae,and 37 Angiospermae),of which 16 were endemics,which indicates the mountain's significance as a biodiversity hotspot.Of these endemic taxa,nine were classified as Endangered(EN)and four as Least Concern(LC),together accounting for over 80%of the endemic flora.The largest angiosperm families with the highest numbers of species included Asteraceae,Lamiaceae,Poaceae,Brassicaceae,Caryophyllaceae and Fabaceae.These six families constituted more than 30%of the recorded flora.Shrubs and perennial herbs were the predominant growth forms,collectively comprising over 70%of the total flora.Native taxa comprised the dominant component of the recorded flora,accounting for 80 species(58.4%of the total).In contrast,non-native taxa were limited to two annual grasses.Analysis of IUCN Red List proportions revealed a predominance of EN taxa,accounting for 52 taxa(37.9%),followed by Least Concern(LC)taxa with 36 taxa(26.3%).Together,these two categories constituted over 60%of the total assessed flora.Hierarchical cluster analysis of a presence/absence data matrix(49 stands×91 species after removal of species with occurrences<5%),using the Sørensen(Bray-Curtis)method,identified eight distinct vegetation clusters.Each cluster is characterized by one or more dominant species,distinguished by their highest percentage of occurrence(f)within their respective group.Apart from soil reaction(pH)and diversity indices(species richness and Shannon’s index),ANOVA test showed high significant differences in most of the measured environmental variables among the obtained cluster groups(A-H).Canonical Correspondence Analysis(CCA)showed direct correlations between the 7 examined environmental variables and plant species composition in Gebel Katrina.The eight cluster groups were separated along axes 1 and 2 of the diagram.The species-environment correlations were high for the three axes explaining 63.0%of the cumulative variance.The stands of groups(E)and(G)were correlated with coarse sand,stands of group(B)were highly correlated with electric conductivity(EC),and stands of group(F)were correlated with elevation.The endemic flora of Gebel Katrina faces multiple anthropogenic and environmental threats.Overgrazing by livestock,excessive harvesting of plants for fuelwood and traditional medicinal uses,and habitat degradation due to land-use changes have led to significant depletion of vegetation cover and biodiversity loss.展开更多
Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemi...Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemic hotspot for DENV transmission in Vietnam[2,3].The largest outbreak occurred in 2017,with more than 36000 cases and 7 deaths reported,causing by all four serotypes with the predominance of DENV1,following by DENV2[4,5].During the following dengue season,we collected 390 blood and serum samples from 197 hospitalized patients in a national hospital in Hanoi city,Northern Vietnam to identify the circulating DENV serotypes responsible for the 2018-2019 outbreak.展开更多
Introduction: Tuberculosis (TB) remains a significant public health challenge, particularly in high-endemicity settings where latent TB infections (LTBI) contribute to ongoing transmission. Early identification and ma...Introduction: Tuberculosis (TB) remains a significant public health challenge, particularly in high-endemicity settings where latent TB infections (LTBI) contribute to ongoing transmission. Early identification and management of LTBI are crucial in limiting the spread of the disease. This study demonstrates the role of Interferon Gamma Release Assay (IGRA) as a screening tool for latent tuberculosis in high-burden region. Materials and Methods: This retrospective observational study assessed the detection of LTBI using the QuantiFERON-TB Gold Plus (QFT-Plus) test among 145 patients at the Department of Microbiology & Immunology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, from August 2023 to August 2024. The study included patients suspected of TB, those screened before immunosuppressive therapy, organ transplantation, or kidney dialysis. Participants were tested IGRA using QFT-Plus, which detects interferon-gamma (IFN-γ) released in response to Mycobacterium tuberculosis antigens. Results and Discussion: Among 145 patients tested for the QFT-Gold Plus test, 55.17% (n = 80) were positive for LTBI, with a substantial agreement between TB1 and TB2 responses (p Conclusion: The results highlight that QFT-Plus may be utilized as a useful diagnostic screening tool for latent TB in regions with a high disease burden, though challenges related to cost and infrastructure persist. With growing global efforts to eliminate tuberculosis, focused screening and treatment of LTBI in high-risk groups could play a vital role in reducing the progression of TB. The study underscores the importance of targeted screening for LTBI to reduce the progression to active TB, particularly in resource-limited settings.展开更多
Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown ...Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown and has puzzled doctors for many years.A preliminary study on heavy metals and symptoms indicated that arsenic might pose the greatest threat to the health of local residents.Here,to explore the sources of and factors influencing arsenic enrichment in DV,whose residents exhibit signs of arsenic poisoning,the As contents in soil,water,and plants were systematically measured.The results indicated high As contents in plant and soil samples obtained from the area,and the source of As may be linked to the weathering of black shale rock.Ingestion of soil and consumption of plants were the two main As exposure pathways among children and adults,respectively,and children exhibited a higher health risk than adults.We presume and emphasize that when extreme drought events occur,humans might face unusual risks resulting from exposure to toxic elements and the direct consumption of highly polluted water.Our study provides a new perspective and sheds light on the environmental geochemistry and health links of this disease.展开更多
Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting a...Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.展开更多
Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the M...Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the Mountains of Southwest China.Although surveys of mammals in this ecologically important region have a long history,there is no comprehensive systematic checklist and distribution account of the mammals of GLGM.Here,we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews.We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns.We recorded 212 mammal species in nine orders,33 families,and 119 genera,which accounts for 30.5%of China’s mammal species,and a high proportion of nationally protected(50)and globally threatened(29)species.Mammal species richness showed a symmetrical unimodal curve along the elevation gradient,peaking at intermediate elevations(2000 to 2500 m above sea level(asl)),and increasing generally from south to north,slightly higher in the east slope than in the west.Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages(<900 m asl.,900-3500 m asl.,and>3500 m asl)and significant south-to-north variation,but no substantial differences between the east and west slopes.The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species,complex faunal composition,high endemism,and being the distribution boundary for many species.This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.展开更多
BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a h...BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate.CASE SUMMARY A 58-year-old woman presented with scattered erythema on the skin of her limbs,followed by fever and seizures.B.pseudomallei was isolated successively from the patient’s urine,blood,and pus.Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region.Subsequently,abscess resection and drainage were performed.The patient showed no signs of relapse after 4 months of follow-up visits post-treatment.CONCLUSION We present here a unique case of multi-systemic melioidosis that occurs in nonendemic regions in a patient who had no recent travel history.Hence,it is critical to enhance awareness of melioidosis in non-endemic regions.展开更多
Much of the world's biodiversity lies in heterogeneous mountain areas with their diverse environments.As an example,Iranian montane ranges are highly diverse,particularly in the Irano-Turanian phytogeographical re...Much of the world's biodiversity lies in heterogeneous mountain areas with their diverse environments.As an example,Iranian montane ranges are highly diverse,particularly in the Irano-Turanian phytogeographical region.Understanding plant diversity patterns with increasing elevation is of high significance,not least for conservation planning.We studied the pattern of species richness,Shannon diversity,endemic richness,endemics ratio,and richness of life forms along a 3900 m elevational transect in Mount Palvar,overlooking the Lut Desert in Southeast Iran.We also analyzed the effect of environmental variables on species turnover along the vertical gradient.A total of 120 vegetation plots(10 m×10 m)were sampled along the elevational transect containing species and environmental data.To discover plant diversity pattern along the elevational gradient,generalized additive model(GAM)was used.Non-metric multidimensional scaling(NMDS)was applied for illustrating the correlation between species composition and environmental variables.We found hump-shaped pattern for species richness,Shannon diversity,endemic richness,and species richness of different life forms,but a monotonic increasing pattern for ratio of endemic species from low to high elevations.Our study confirms the humped pattern of species richness peaking at intermediate elevations along a complete elevational gradient in a semi-arid mountain.The monotonic increase of endemics ratio with elevation in our area as a case study is consistent with global increase of endemism with elevation.According to our results,temperature and precipitation are two important climatic variables that drive elevational plant diversity,particularly in seasonally dry areas.Our study suggests that effective conservation and management are needed for this low latitude mountain area along with calling for long-term monitoring for species redistribution.展开更多
文摘The scientific community faces the challenge of measuring progress toward biodiversity targets and indices have been traditionally used.However,recent inventories in secondary tropical mountain forests using traditional biodiversity indices have yielded results that are indistinct with primary ones.This shows the need to develop complementary indices that goes beyond species count but integrates the distribution and conservation status of the species.This study developed endemicity and conservation importance index for tropical forest that incorporated the distribution and conservation status of the species.These indices were applied to Mt.Natoo,a remnant primary mossy forest in Buguias,Benguet,Philippines,that resulted to endemicity index of 81.07 and conservation importance index of 42.90.Comparing these with secondary forest sites with comparable Shannon-Wiener,Simpson,Evenness and Margalef’s indices,our endemicity and conservation indices clearly differentiates primary forest(our study site)with higher values from secondary forests with much lower values.Thus,we are proposing these indices for a direct but scientifically-informed identification of specific sites for conservation and protection in tropical forests.Additionally,our study documented a total of 168 vascular plant species(79 endemic and 12 locally threatened species)in Mt.Nato-o.Majority are of tropical elements for both generic and species levels with some temperate elements that could be attributed to the site's high elevation and semi-temperate climate.These are important baseline information for conservation plans and monitoring of tropical mossy forests.
文摘Mosquito-borne infections are of global health concern because of their rapid spread and upsurge,which creates a risk for coinfections.chikungunya virus(CHIKV),an arbovirus disease transmitted by Aedes aegypti or A.albopictus,and malaria,a parasitic disease transmitted by Anopheles gambiae,are prevalent in Nigeria and neighbouring countries,but their burden and possible coinfections are poorly understood.In this study,we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses(ZIKV)in three regions of Nigeria.A cross-sectional serosurvey was conducted on 871 participants.Samples were collected from outpatients by simple random sampling.Analyses of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP(virus like particle),ZIKV NS1 and ZIKV Equad according to manufacturers’instructions and malaria RDT for malaria parasite.There was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions(69.5%,291/419),while ZIKV-seropositivity(22.4%,34/152)and CHIKV-ZIKV co-circulating antibody seropositivity(17.8%,27/152)were notably higher in the southern region than in the central and northern regions.This investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian regions.The seropositivity of detectable antibodies differed among the three geographical locations.
文摘We are currently faced with the question of how the CoV-2 severity may change in the years ahead.Our analysis of immunological and epidemiological data on endemic human coronaviruses(HCoVs)shows that infection-blocking immunity wanes rapidly,but disease-reducing immunity is long-lived.Our model,incorporating these components of immunity,recapitulates both the current severity of CoV-2 and the benign nature of HCoVs,suggesting that once the endemic phase is reached and primary exposure is in childhood,CoV-2 may be no more virulent than the common cold.
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
文摘Objective Cholera caused by Vibrio cholerae biotype eltor (EVC) is an endemic disease, subsiding in winter and reappearing in spring and summer Investigating the state of EVC during the intermittent time is of crucial importance in controlling this disease Methods Different factors mimicking the internal and external environmental conditions of the host, including human and fish bile, bacterial phages and antibiotics were used experimentally to induce variation in EVC EVC variants were isolated from the stool of diarrhea patients and river water in old endemic areas during the winter The variants obtained were tested with gene probe hybridization, DNA restriction enzyme mapping, immunoenzyme staining and animal passaging Results Due to the loss of cell walls, 3 kinds of EVC variants were obtained during induction: the L form variant, with a complete loss of cell walls; the nonagglutinating variants, with the loss of surface O antigen; the phage resistant variants, with the loss of phage receptors Similar variants were found in field isolation This variation was proved to be phenotypic, with no change in genetic material: it was reversible and appeared in a seasonal pattern, which coincided with the endemicity of this disease Passage in animal enhanced this reversion In compensation for the loss of cell walls, cell membranes were greatly thickened, increasing the ability of the variants to survive during the unfavorable winter conditions Conclusions EVC varied in a seasonal pattern, coincident with the endemicity of this disease The compensatory thickening of the cell membranes protects the EVC variants to survive the winter
基金funded by the Life Seedforce(Life20 NAT/IT/001468)。
文摘Salt stress might be an important factor that decreases the emergence of seedlings and reduces plants'growth,causing their endangered status.However,the effects of salt stress on the germination of the Mediterranean species are less concern.Limonium strictissimum(Salzm.)Arrigoni,part of the group related to Limonium articulatum(Loisel.)Kuntze,is a Cyrno-Sardinian endemism,which is included in the International Union for Conservation of Nature(IUCN)Red Lists as Endangered(EN).Fresh seeds of L.strictissimum harvested from the only known population in Sardinia and a population in southeastern Corsica were used with the aims to study the effects of temperature and salinity on the seed germination and to evaluate the ability to recover their germination after exposure to salt stress.In both populations,empty fruits with a lower percentage were observed in Sardinia than in Corsica.The seeds showed a high germination capacity,which was not influenced by temperature and did not even differ between the two populations.Compared with non-saline condition,the presence of salt in the substrate,independently of the concentration tested,inhibited seed germination in both populations,with germination percentages never exceeding 40%.The Sardinian population showed a recovery capacity after exposure to high salt stress,always above 50%regardless of the salt concentration and incubation temperature considered.The seeds previously exposed to 125 mM NaCl at 30℃ had the lowest recovery percentage(56%),while the highest recovery percentage(84%)was recorded at 25℃ with a concentration of 250 mM NaCl.Differently,the Corsican population recorded a higher recovery percentage(54%)in seeds previously exposed to 500 mM NaCl at 20℃,while for the concentration of 125 mM NaCl,the best recovery percentage(11%)was recorded at 30℃.The ability of L.strictissimum to recover germination after salt exposure can be interpreted as an adaptation to the coastal habitats in which it grows.This study provides new insights into the ecophysiology of L.strictissimum seed germination,which could help preserve and implement effective conservation measures for this endangered species with restricted populations.
文摘Gebel Katrina,located in the Saint Catherine Protectorate of South Sinai(Egypt),is a biologically rich area with diverse plant communities shaped by factors such as elevation,slope,soil type,and precipitation.This study was designed to examine the vegetation structure,update the occurrence of endemic taxa,and investigate the impact of environmental conditions and landform types on plant disruption in the region.The primary objective of this study was to analyze the behavior and distribution of the most common species across major environmental gradients.Between 2022 and 2024,49 stands were randomly collected within the study area characterized by relatively uniform vegetation and physiography and represent as much as possible the four major landform types(terraces,slopes,ridges,and gorges).The selected stands were distributed as follows:terraces(12 stands),slopes(9 stands),ridges(9 stands),and gorges(19 stands).For the analysis of the biological spectrum,a growth-form system with four categories was utilized:trees(T),shrubs(S),perennial herbs(PH),and annual herbs(A).Soil analyses were conducted for composite samples from the 49 stands.For each recorded species,nativity,species diversity measurements,endemism,and IUCN conservation status were depicted.Multivariate analysis techniques were used to assess the classification of the 49 stands in various landforms,and ordination with soil variables were applied using different software.A total of 137 taxa were recorded from Gebel Katrina area belonging to 39 families(1 Pteridaceae,1 Ephedraceae,and 37 Angiospermae),of which 16 were endemics,which indicates the mountain's significance as a biodiversity hotspot.Of these endemic taxa,nine were classified as Endangered(EN)and four as Least Concern(LC),together accounting for over 80%of the endemic flora.The largest angiosperm families with the highest numbers of species included Asteraceae,Lamiaceae,Poaceae,Brassicaceae,Caryophyllaceae and Fabaceae.These six families constituted more than 30%of the recorded flora.Shrubs and perennial herbs were the predominant growth forms,collectively comprising over 70%of the total flora.Native taxa comprised the dominant component of the recorded flora,accounting for 80 species(58.4%of the total).In contrast,non-native taxa were limited to two annual grasses.Analysis of IUCN Red List proportions revealed a predominance of EN taxa,accounting for 52 taxa(37.9%),followed by Least Concern(LC)taxa with 36 taxa(26.3%).Together,these two categories constituted over 60%of the total assessed flora.Hierarchical cluster analysis of a presence/absence data matrix(49 stands×91 species after removal of species with occurrences<5%),using the Sørensen(Bray-Curtis)method,identified eight distinct vegetation clusters.Each cluster is characterized by one or more dominant species,distinguished by their highest percentage of occurrence(f)within their respective group.Apart from soil reaction(pH)and diversity indices(species richness and Shannon’s index),ANOVA test showed high significant differences in most of the measured environmental variables among the obtained cluster groups(A-H).Canonical Correspondence Analysis(CCA)showed direct correlations between the 7 examined environmental variables and plant species composition in Gebel Katrina.The eight cluster groups were separated along axes 1 and 2 of the diagram.The species-environment correlations were high for the three axes explaining 63.0%of the cumulative variance.The stands of groups(E)and(G)were correlated with coarse sand,stands of group(B)were highly correlated with electric conductivity(EC),and stands of group(F)were correlated with elevation.The endemic flora of Gebel Katrina faces multiple anthropogenic and environmental threats.Overgrazing by livestock,excessive harvesting of plants for fuelwood and traditional medicinal uses,and habitat degradation due to land-use changes have led to significant depletion of vegetation cover and biodiversity loss.
基金the“Metropolitan Mosquitoes Project”funded by the Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning(Formas,grant number 2016-00364).
文摘Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemic hotspot for DENV transmission in Vietnam[2,3].The largest outbreak occurred in 2017,with more than 36000 cases and 7 deaths reported,causing by all four serotypes with the predominance of DENV1,following by DENV2[4,5].During the following dengue season,we collected 390 blood and serum samples from 197 hospitalized patients in a national hospital in Hanoi city,Northern Vietnam to identify the circulating DENV serotypes responsible for the 2018-2019 outbreak.
文摘Introduction: Tuberculosis (TB) remains a significant public health challenge, particularly in high-endemicity settings where latent TB infections (LTBI) contribute to ongoing transmission. Early identification and management of LTBI are crucial in limiting the spread of the disease. This study demonstrates the role of Interferon Gamma Release Assay (IGRA) as a screening tool for latent tuberculosis in high-burden region. Materials and Methods: This retrospective observational study assessed the detection of LTBI using the QuantiFERON-TB Gold Plus (QFT-Plus) test among 145 patients at the Department of Microbiology & Immunology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, from August 2023 to August 2024. The study included patients suspected of TB, those screened before immunosuppressive therapy, organ transplantation, or kidney dialysis. Participants were tested IGRA using QFT-Plus, which detects interferon-gamma (IFN-γ) released in response to Mycobacterium tuberculosis antigens. Results and Discussion: Among 145 patients tested for the QFT-Gold Plus test, 55.17% (n = 80) were positive for LTBI, with a substantial agreement between TB1 and TB2 responses (p Conclusion: The results highlight that QFT-Plus may be utilized as a useful diagnostic screening tool for latent TB in regions with a high disease burden, though challenges related to cost and infrastructure persist. With growing global efforts to eliminate tuberculosis, focused screening and treatment of LTBI in high-risk groups could play a vital role in reducing the progression of TB. The study underscores the importance of targeted screening for LTBI to reduce the progression to active TB, particularly in resource-limited settings.
基金supported by the National Natural Science Foundation of China(Nos.41820104008 and U2202207)the Special Project for Social Development of Yunnan Province(No.202103AC100001)。
文摘Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown and has puzzled doctors for many years.A preliminary study on heavy metals and symptoms indicated that arsenic might pose the greatest threat to the health of local residents.Here,to explore the sources of and factors influencing arsenic enrichment in DV,whose residents exhibit signs of arsenic poisoning,the As contents in soil,water,and plants were systematically measured.The results indicated high As contents in plant and soil samples obtained from the area,and the source of As may be linked to the weathering of black shale rock.Ingestion of soil and consumption of plants were the two main As exposure pathways among children and adults,respectively,and children exhibited a higher health risk than adults.We presume and emphasize that when extreme drought events occur,humans might face unusual risks resulting from exposure to toxic elements and the direct consumption of highly polluted water.Our study provides a new perspective and sheds light on the environmental geochemistry and health links of this disease.
基金supported by the National Natural Science Foundation of China(32271737,32071544)the Interdisciplinary Innovation Team of the Chinese Academy of Sciences(CAS)“Light of West China”Program(xbzg-zdsys-202207)+1 种基金the Shenzhen Zhilan Foundation(2021070451A)Nature Science Foundation of Sichuan Province(2022NSFSC0125).
文摘Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.
基金supported by the National Key Research and Development Program of China(2022YFC2602500,2022YFC2601200)Major Science and Technique Programs in Yunnan Province(202102AA310055)+6 种基金Science and Technology Basic Resources Investigation Program of China(2021FY100200)Project for Talent and Platform of Science and Technology in Yunnan Province Science and Technology Department(202205AM070007)National Natural Science Foundation of China(32000304)Yunnan Fundamental Research Projects(202101AT070294)Chinese Academy of Sciences“Light of West China”Program and Yunnan Revitalization Talent Support Program Young Talent Project(XDYC-QNRC-2022-0379 to Q.L.)Chinese Academy of Sciences“Light of West China”Program(292021000004 to X.Y.L.)Yunnan Provincial Youth Talent Support Program(YNWR-QNBJ-2020-127 to X.Y.L.)。
文摘Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the Mountains of Southwest China.Although surveys of mammals in this ecologically important region have a long history,there is no comprehensive systematic checklist and distribution account of the mammals of GLGM.Here,we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews.We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns.We recorded 212 mammal species in nine orders,33 families,and 119 genera,which accounts for 30.5%of China’s mammal species,and a high proportion of nationally protected(50)and globally threatened(29)species.Mammal species richness showed a symmetrical unimodal curve along the elevation gradient,peaking at intermediate elevations(2000 to 2500 m above sea level(asl)),and increasing generally from south to north,slightly higher in the east slope than in the west.Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages(<900 m asl.,900-3500 m asl.,and>3500 m asl)and significant south-to-north variation,but no substantial differences between the east and west slopes.The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species,complex faunal composition,high endemism,and being the distribution boundary for many species.This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.
文摘BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate.CASE SUMMARY A 58-year-old woman presented with scattered erythema on the skin of her limbs,followed by fever and seizures.B.pseudomallei was isolated successively from the patient’s urine,blood,and pus.Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region.Subsequently,abscess resection and drainage were performed.The patient showed no signs of relapse after 4 months of follow-up visits post-treatment.CONCLUSION We present here a unique case of multi-systemic melioidosis that occurs in nonendemic regions in a patient who had no recent travel history.Hence,it is critical to enhance awareness of melioidosis in non-endemic regions.
文摘Much of the world's biodiversity lies in heterogeneous mountain areas with their diverse environments.As an example,Iranian montane ranges are highly diverse,particularly in the Irano-Turanian phytogeographical region.Understanding plant diversity patterns with increasing elevation is of high significance,not least for conservation planning.We studied the pattern of species richness,Shannon diversity,endemic richness,endemics ratio,and richness of life forms along a 3900 m elevational transect in Mount Palvar,overlooking the Lut Desert in Southeast Iran.We also analyzed the effect of environmental variables on species turnover along the vertical gradient.A total of 120 vegetation plots(10 m×10 m)were sampled along the elevational transect containing species and environmental data.To discover plant diversity pattern along the elevational gradient,generalized additive model(GAM)was used.Non-metric multidimensional scaling(NMDS)was applied for illustrating the correlation between species composition and environmental variables.We found hump-shaped pattern for species richness,Shannon diversity,endemic richness,and species richness of different life forms,but a monotonic increasing pattern for ratio of endemic species from low to high elevations.Our study confirms the humped pattern of species richness peaking at intermediate elevations along a complete elevational gradient in a semi-arid mountain.The monotonic increase of endemics ratio with elevation in our area as a case study is consistent with global increase of endemism with elevation.According to our results,temperature and precipitation are two important climatic variables that drive elevational plant diversity,particularly in seasonally dry areas.Our study suggests that effective conservation and management are needed for this low latitude mountain area along with calling for long-term monitoring for species redistribution.
