在江西婺源的浙江红山茶天然林分里发现少量的白花变异植株,花色在White Group NN155B～C之间。白花变异植株树型、叶型、果型与浙江红山茶原种整体差别不大。为鉴定这类变异植株是新物种亦或是原种变种或变型,本文利用RPB2低拷贝核基...在江西婺源的浙江红山茶天然林分里发现少量的白花变异植株,花色在White Group NN155B～C之间。白花变异植株树型、叶型、果型与浙江红山茶原种整体差别不大。为鉴定这类变异植株是新物种亦或是原种变种或变型,本文利用RPB2低拷贝核基因标记开展红山茶组与油茶组主要近缘种的分子甄别。研究结果显示,各山茶属物种的kimur2-parameter平均距离为0.019,与各近缘种比较,浙江红山茶与油茶组的越南油茶、普通油茶有更近的亲缘关系。浙江红山茶原种与白花变异kimur2-parameter距离仅为0.005,远小于各近缘种间距离。系统发育树显示包括白花变异的浙江红山茶不同个体能按同一物种聚成一类与其他物种分离,结果支持白花变异作为浙江红山茶变异类型进行归并。研究将浙江红山茶与其近缘种区分出来,进一步为生产应用中浙江红山茶种真实性甄别提供了可靠的研究方法,同时也为浙江红山茶白花新品种考证提供了重要的分子依据。展开更多
Terrestrial invasive plant species continue to wreak havoc on a global economic and ecological scale. With the advent of climate change and pending future catastrophes, the spread of resilient invasive plants will onl...Terrestrial invasive plant species continue to wreak havoc on a global economic and ecological scale. With the advent of climate change and pending future catastrophes, the spread of resilient invasive plants will only increase exponentially. Here, the search continues for a better understanding of the below-ground microbially driven mechanisms involved in plant invasion where other above-ground mechanisms have been exhausted. Microbes govern the world around us and interact with every living and non-living facet of the world. To reinforce the important underpinnings of the role of microorganisms in plant invasion, a systematic review of recently published articles was undertaken. Using the ScienceDirect database, five (5) search queries were used to generate 1221 research articles. After a two-step reduction was made based on relevance of the articles, a final total of 59 articles were retrieved. An additional 18 relevant articles were also assessed through the PubMed database for analysis to account for other invasive plants. Thirty-seven (37) invasive species were investigated where soil physiochemical and microbial community structure changes were most prevalent (32% & 39% respectively) while enhanced mutualism, allelopathy and pathogen accumulation were reported less (16%, 10% & 3% respectively). In all invasive species assessed, the impact on plant invasion and inability of the native plants to compete was due to specific microbial associations of the invasive plant or disruption of the soil microbial community. This microbial community shift coincided with changes in physiochemical properties of the soil and the subsequent negative soil feedback for native plants. There is still an expanding potential for the use of biocontrol agents to aid restoration once the underpinnings of biotic resistance and enemy release are understood in a microbial and physiochemical context. The active and functional microbial community structure of the invasive plant rhizosphere and adjacent soil in its native and non-native region can offer a better inference of how they can be controlled using novel-below ground biocontrol methods.展开更多
State-approved membrane filtration (MF) techniques for water quality assessments were contrasted with metagenomic shotgun sequencing (MSS) protocols to evaluate their efficacy in providing precise health-risk indices ...State-approved membrane filtration (MF) techniques for water quality assessments were contrasted with metagenomic shotgun sequencing (MSS) protocols to evaluate their efficacy in providing precise health-risk indices for surface waters. Samples from a freshwater receiving pond (ABI-1002) and two upstream storm water ditches (ABI-1003) and (ABI-1004) yielded alarmingly high <em>Fecal coliform</em> MF densities of 220, >2000 and >2000 CFU/100ml respectively. The indicator, <em>Enterococcus</em> bacteria exceeded allowable limits in all but the equipment control (ABI-1001). Using MSS, the relative numerical abundance of pathogenic bacteria, virulence and antibiotic resistance genes revealed the status and potential pollution sources of each ditch. High levels of <em>Shigella</em><em> sp</em>. (0 (ABI-1001), 4945 (ABI-1002), 55,008 (ABI-1003), and 2221 (ABI-1004) genomic reads/100ml) correlated with virulence genes and antibiotic resistance genes found in fecal samples for ABI1003 and not ABI1004. Traditional culture methods (TCM) showed possible fecal contamination in two of the four samples, and no contamination in the others. MSS clearly distinguished between fecal and environmental bacteria contamination sources, and pinpointed actual risks from pathogens. Our data underscore the potential utility of MSS in precision risk assessment for public and biodiversity health and tracking of environmental microbiomes shifts by field managers and policy makers.展开更多
The palm family(Arecaceae),consisting of2600 species,is the third most economically important family of plants.The African oil palm(Elaeis guineensis)is one of the most important palms.However,the genome sequences of ...The palm family(Arecaceae),consisting of2600 species,is the third most economically important family of plants.The African oil palm(Elaeis guineensis)is one of the most important palms.However,the genome sequences of palms that are currently available are still limited and fragmented.Here,we report a high-quality chromosome-level reference genome of an oil palm,Dura,assembled by integrating long reads with150 genome coverage.The assembled genome was 1.7 Gb in size,covering 94.5%of the estimated genome,of which 91.6%was assigned into 16 pseudochromosomes and 73.7%was repetitive sequences.Relying on the conserved synteny with oil palm,the existing draft genome sequences of both date palm and coconut were further assembled into chromosomal level.Transposon burst,particularly long terminal repeat retrotransposons,following the last whole-genome duplication,likely explains the genome size variation across palms.Sequence analysis of the VIRESCENS gene in palms suggests that DNA variations in this gene are related to fruit colors.Recent duplications of highly tandemly repeated pathogenesis-related proteins from the same tandem arrays play an important role in defense responses to Ganoderma.Whole-genome resequencing of both ancestral African and introduced oil palms in Southeast Asia reveals that genes under putative selection are notably associated with stress responses,suggesting adaptation to stresses in the new habitat.The genomic resources and insights gained in this study could be exploited for accelerating genetic improvement and understanding the evolution of palms.展开更多
Aim:This study aimed to compare mini-invasive liver resection(MILR)(laparoscopic/robotic approach)and open liver resection(OLR)for hepatocellular carcinoma(HCC)in elderly patients with regard to clinical and oncologic...Aim:This study aimed to compare mini-invasive liver resection(MILR)(laparoscopic/robotic approach)and open liver resection(OLR)for hepatocellular carcinoma(HCC)in elderly patients with regard to clinical and oncological outcomes through a comprehensive systematic review.Methods:The MEDLINE and Cochrane Library electronic databases were systematically searched from 2009 to December 2019 to identify relevant English written studies comparing MILR and OLR.The main endpoints were Child-Pugh score,serum total bilirubin level,comorbidity,presence/absence of cirrhosis,minor/major resection,challenge segment approach,operative time,estimated intraoperative blood loss,liver failure rate,morbidity according to the Clavien-Dindo classification,length of hospital stay(LOS),postoperative mortality,number of lesions,tumor size,readmission rate,recurrence rate and survival at 1,3 and 5 years after operation.Meta-analyses provided pooled relative risks and mean differences for these outcomes.Cut-off for"elderly age"was set at 65 years old.Results:Eight studies that evaluated 3051 patients who underwent liver resection for HCC,with 950 undergoing MILR and 2101 OLR,were included after the screening process.Blood loss,morbidity,and LOS showed statistical significance in favor of MILR.In particular,with respect to OLR,MILR decreased on average blood loss by 161.43 mL(95%CI:250.24-72.61),risk of morbidity by 42%(P<0.01),LOS by 4 days(95%CI:7-2),postoperative mortality risk by 47%(although not significantly,P=0.06).Major resections were significantly more common in the OLR group(P<0.0001).Recurrence,although not significant(P=0.06),must also be emphasized.The two surgical approaches were comparable with regard to the other outcomes investigated.Conclusion:Meta-analyses confirmed the advantages of MILR in terms of short perioperative outcomes,where it may promote the extension of liver resection to HCC patients with borderline liver function.MILR may be considered an important treatment option with significant benefits in the elderly and fragile patients.However,large well-designed prospective comparative studies or randomized controlled trials would be necessary to further confirm our conclusions.展开更多
文摘在江西婺源的浙江红山茶天然林分里发现少量的白花变异植株,花色在White Group NN155B～C之间。白花变异植株树型、叶型、果型与浙江红山茶原种整体差别不大。为鉴定这类变异植株是新物种亦或是原种变种或变型,本文利用RPB2低拷贝核基因标记开展红山茶组与油茶组主要近缘种的分子甄别。研究结果显示,各山茶属物种的kimur2-parameter平均距离为0.019,与各近缘种比较,浙江红山茶与油茶组的越南油茶、普通油茶有更近的亲缘关系。浙江红山茶原种与白花变异kimur2-parameter距离仅为0.005,远小于各近缘种间距离。系统发育树显示包括白花变异的浙江红山茶不同个体能按同一物种聚成一类与其他物种分离,结果支持白花变异作为浙江红山茶变异类型进行归并。研究将浙江红山茶与其近缘种区分出来,进一步为生产应用中浙江红山茶种真实性甄别提供了可靠的研究方法,同时也为浙江红山茶白花新品种考证提供了重要的分子依据。
文摘Terrestrial invasive plant species continue to wreak havoc on a global economic and ecological scale. With the advent of climate change and pending future catastrophes, the spread of resilient invasive plants will only increase exponentially. Here, the search continues for a better understanding of the below-ground microbially driven mechanisms involved in plant invasion where other above-ground mechanisms have been exhausted. Microbes govern the world around us and interact with every living and non-living facet of the world. To reinforce the important underpinnings of the role of microorganisms in plant invasion, a systematic review of recently published articles was undertaken. Using the ScienceDirect database, five (5) search queries were used to generate 1221 research articles. After a two-step reduction was made based on relevance of the articles, a final total of 59 articles were retrieved. An additional 18 relevant articles were also assessed through the PubMed database for analysis to account for other invasive plants. Thirty-seven (37) invasive species were investigated where soil physiochemical and microbial community structure changes were most prevalent (32% & 39% respectively) while enhanced mutualism, allelopathy and pathogen accumulation were reported less (16%, 10% & 3% respectively). In all invasive species assessed, the impact on plant invasion and inability of the native plants to compete was due to specific microbial associations of the invasive plant or disruption of the soil microbial community. This microbial community shift coincided with changes in physiochemical properties of the soil and the subsequent negative soil feedback for native plants. There is still an expanding potential for the use of biocontrol agents to aid restoration once the underpinnings of biotic resistance and enemy release are understood in a microbial and physiochemical context. The active and functional microbial community structure of the invasive plant rhizosphere and adjacent soil in its native and non-native region can offer a better inference of how they can be controlled using novel-below ground biocontrol methods.
文摘State-approved membrane filtration (MF) techniques for water quality assessments were contrasted with metagenomic shotgun sequencing (MSS) protocols to evaluate their efficacy in providing precise health-risk indices for surface waters. Samples from a freshwater receiving pond (ABI-1002) and two upstream storm water ditches (ABI-1003) and (ABI-1004) yielded alarmingly high <em>Fecal coliform</em> MF densities of 220, >2000 and >2000 CFU/100ml respectively. The indicator, <em>Enterococcus</em> bacteria exceeded allowable limits in all but the equipment control (ABI-1001). Using MSS, the relative numerical abundance of pathogenic bacteria, virulence and antibiotic resistance genes revealed the status and potential pollution sources of each ditch. High levels of <em>Shigella</em><em> sp</em>. (0 (ABI-1001), 4945 (ABI-1002), 55,008 (ABI-1003), and 2221 (ABI-1004) genomic reads/100ml) correlated with virulence genes and antibiotic resistance genes found in fecal samples for ABI1003 and not ABI1004. Traditional culture methods (TCM) showed possible fecal contamination in two of the four samples, and no contamination in the others. MSS clearly distinguished between fecal and environmental bacteria contamination sources, and pinpointed actual risks from pathogens. Our data underscore the potential utility of MSS in precision risk assessment for public and biodiversity health and tracking of environmental microbiomes shifts by field managers and policy makers.
基金supported by the Internal Funds of the Temasek Life Sciences Laboratory,Singapore(Grant No.5020)Wilmar International,Singapore(Grant No.9200).
文摘The palm family(Arecaceae),consisting of2600 species,is the third most economically important family of plants.The African oil palm(Elaeis guineensis)is one of the most important palms.However,the genome sequences of palms that are currently available are still limited and fragmented.Here,we report a high-quality chromosome-level reference genome of an oil palm,Dura,assembled by integrating long reads with150 genome coverage.The assembled genome was 1.7 Gb in size,covering 94.5%of the estimated genome,of which 91.6%was assigned into 16 pseudochromosomes and 73.7%was repetitive sequences.Relying on the conserved synteny with oil palm,the existing draft genome sequences of both date palm and coconut were further assembled into chromosomal level.Transposon burst,particularly long terminal repeat retrotransposons,following the last whole-genome duplication,likely explains the genome size variation across palms.Sequence analysis of the VIRESCENS gene in palms suggests that DNA variations in this gene are related to fruit colors.Recent duplications of highly tandemly repeated pathogenesis-related proteins from the same tandem arrays play an important role in defense responses to Ganoderma.Whole-genome resequencing of both ancestral African and introduced oil palms in Southeast Asia reveals that genes under putative selection are notably associated with stress responses,suggesting adaptation to stresses in the new habitat.The genomic resources and insights gained in this study could be exploited for accelerating genetic improvement and understanding the evolution of palms.
文摘Aim:This study aimed to compare mini-invasive liver resection(MILR)(laparoscopic/robotic approach)and open liver resection(OLR)for hepatocellular carcinoma(HCC)in elderly patients with regard to clinical and oncological outcomes through a comprehensive systematic review.Methods:The MEDLINE and Cochrane Library electronic databases were systematically searched from 2009 to December 2019 to identify relevant English written studies comparing MILR and OLR.The main endpoints were Child-Pugh score,serum total bilirubin level,comorbidity,presence/absence of cirrhosis,minor/major resection,challenge segment approach,operative time,estimated intraoperative blood loss,liver failure rate,morbidity according to the Clavien-Dindo classification,length of hospital stay(LOS),postoperative mortality,number of lesions,tumor size,readmission rate,recurrence rate and survival at 1,3 and 5 years after operation.Meta-analyses provided pooled relative risks and mean differences for these outcomes.Cut-off for"elderly age"was set at 65 years old.Results:Eight studies that evaluated 3051 patients who underwent liver resection for HCC,with 950 undergoing MILR and 2101 OLR,were included after the screening process.Blood loss,morbidity,and LOS showed statistical significance in favor of MILR.In particular,with respect to OLR,MILR decreased on average blood loss by 161.43 mL(95%CI:250.24-72.61),risk of morbidity by 42%(P<0.01),LOS by 4 days(95%CI:7-2),postoperative mortality risk by 47%(although not significantly,P=0.06).Major resections were significantly more common in the OLR group(P<0.0001).Recurrence,although not significant(P=0.06),must also be emphasized.The two surgical approaches were comparable with regard to the other outcomes investigated.Conclusion:Meta-analyses confirmed the advantages of MILR in terms of short perioperative outcomes,where it may promote the extension of liver resection to HCC patients with borderline liver function.MILR may be considered an important treatment option with significant benefits in the elderly and fragile patients.However,large well-designed prospective comparative studies or randomized controlled trials would be necessary to further confirm our conclusions.
