华南南亚热带不同演替阶段植被的环境效应

This study deals with the capacity for nutrient conservation,the balance of carbon and oxygen as well as the buffering of acid rain in the succession of vegetation of lower subtropical zone of southern China.The results show that:(1)N,P,K contents of plants of a 100 year old monsoon evergreen broad leaved forest were 12～39 times those of the grassland and fernland.They were 12～16 times those of the shrubland.Its N,P,K contents of litter were 11～36 times those of grassland and fernland,and 3.1～5.2 times tha...研究华南南亚热带不同演替阶段植被对养分保护、碳氧平衡和对酸雨的缓冲作用的结果表明: 100 年生季风常绿阔叶林植物N、P、K 贮量是草地和芒萁群落的12 ～39 倍, 灌木林的12～16 倍; 死地被物N、P、K 贮量是草地和芒萁群落的11～36倍, 灌木林的3. 1～5. 2 倍. 30 年生季风常绿阔叶林净初级生产量的N、P、K 贮量是草地、芒萁、灌木群落的1. 9～5. 1 倍. º 100年生季风常绿阔叶林植物碳贮量是草地、芒萁、灌木群落的13～49 倍. 30 年生季风常绿阔叶林植物碳净固定量是草地、芒萁、灌木群落的2. 3～3. 4 倍, 前者的氧释放量也明显大于后者. » 芒萁、灌木群落和季风常绿阔叶林穿透雨的平均pH 值比降雨pH 值分别高1. 13、1. 03 和1. 90 个单位, 季风常绿阔叶林对酸雨的缓冲能力明显高于芒萁、灌木群落. ¼正向演替可加强植被的环境效应, 让草地、芒萁、灌木群落演替成为季风常绿阔叶林, 有利于区域生态环境的改善.This study deals with the capacity for nutrient conservation, the balance of carbon and oxygen as well as the buffering of acid rain in the succession of vegetation of lower subtropical zone of southern China. The results show that: (1)N,P,K contents of plants of a 100 year old monsoon evergreen broad-leaved forest were 12-39 times those of the grassland and fernland. They were 12-16 times those of the shrubland. Its N,P,K contents of litter were 11-36 times those of grassland and fernland,and 3.1-5. 2 times that of the shrubland. The mass of N,P,K in net primary production of 30 year old monsoon evergreen broad-leaved forest were 1. 9-5.1 times those measured in the grassland,fernland and shrubland. (2)Carbon content of plants of the 100 year old monsoon evergreen broad-leaved forest was 13-49 times those of in the grassland,fernland and shrubland. The amount of fixed carbon in the 30 year old monsoon evergreen broad-leaved forest was 2. 3-3. 4 times those of the grassland,fernland and shrubland. The amount of oxygen made in the former was,obviously,also greater than in the latter. (3)Mean pH values of throughfall from the fernland, shrubland and monsoon evergreen broad-leaved forest were 1. 13,1. 03 and 1. 90 units higher than that of rainfall. The buffering capacity of the monsoon evergreen broad-leaved forest for acid rain was significantly higher than that of the fernland and shrubland. (4) The environment effects of vegetation could be increased by succession. It is very helpful for improving the eco- environment if the grassland,fernland and shrubland are changed to monsoon evergreen broad-leaved forest by succession.link_to_subscribed_fulltextpostprin

Fingerprinting sediment source: the example of a drainage basin in Devon, UK

In view of the many difficulties associated with the determination of the source of suspended sediment transported by a stream, the 'fingerprinting' technique which employs sediment properties to identify the source offers considerable potential. Several limitations of the technique must, however, be recognised. Results of applying this approach to identifying sediment sources within a small agricultural drainage basin in Devon UK are reported. A variety of sediment properties have been employed in order to test the consistency of the results obtained and a simple mixing model has been used to quantify the relative importance of the contributions from surface soil and channel banks.link_to_subscribed_fulltextpostprin

Cyanobacterial crust in Hong Kong and comments on future research

The existence of cyanobacterial crust in Hong Kong under both experimental and natural conditions was noted. Thirty0three cyanobacterial species were identified from the soil surface at the site of an erosion experiment. Eleven species were unicellular and 22 filamentous. Fourteen were non-heterocystous and 8 heterocystous cyanobacterial species. None of the species were obligate terrestrial species. Species abundance was measured for one year, and clear seasonal and aseasonal groups of species were established. Macro-environmental data were reported, including soil characteristics, rainfall, rainfall variability and pH, both soil and surface runoff. While the crusts appeared to be fairly stable, except at typhoon intensities, further work is needed to establish degrees of temporal and spatial variation. Non-crust forming cyanobacteria grew on the soil surface under grass and fern. We discuss the future research outlining the potential uses of cyanobacteria in substrate remediation both as an aid to aggregate stability on cut slopes and as a means of accelerating natural plant succession on cut and cement plastered slopes.published_or_final_versio

Rapid changes of precipitation pH in Qinghai Province, the northeastern Tibetan Plateau

Rainfall monitoring programs were conducted in two industrial cities of China's Qinghai Province, Xining and Germu, in some periods of the 1980s and 1990s. The results show that the natural precipitation in this area is originally alkaline. Compared with the late 1980s records, pH values declined significantly from approximately 8 in the 1980s to below 7 in mid-1990s. Such rapid and drastic changes were attributed to fast industrial development that released a large amount of pollutants. Subsequent tough control on pollutant emission partly restored pH values back to above 7 in the late 1990s. The pH and rainfall chemical analyses indicate that alkaline rain in this continental arid region is caused by airborne dusts which originate from local alkaline soils. With decrease of pH value, the total ionic concentration of rainwater is increased because acids were added to the rainwater. © 2002 Elsevier Science B.V. All rights reserved.postprin

The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana

Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific ‘‘avirulent’’ pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NBLRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector

An atlas of seabed biodiversity for Aotearoa New Zealand

\ua9 2023 Copernicus GmbH. All rights reserved. The waters of Aotearoa New Zealand span over 4.2ĝ€\uafmillionĝ€\uafkm2 of the South Pacific Ocean and harbour a rich diversity of seafloor-Associated taxa. Due to the immensity and remoteness of the area, there are significant gaps in the availability of data that can be used to quantify and map the distribution of seafloor and demersal biodiversity, limiting effective management. In this study, we describe the development and accessibility of an online atlas of seabed biodiversity that aims to fill these gaps. Species distribution models were developed for 579 taxa across four taxonomic groups: demersal fish, reef fish, subtidal invertebrates and macroalgae. Spatial layers for taxa distribution based on habitat suitability were statistically validated and then, as a further check, evaluated by taxonomic experts to provide measures of confidence to guide the future use of these layers. Spatially explicit uncertainty (SD) layers were also developed for each taxon distribution. We generated layer-specific metadata, including statistical and expert evaluation scores, which were uploaded alongside the accompanying spatial layers to the open access database Zenodo. This database provides the most comprehensive source of information on the distribution of seafloor taxa for Aotearoa New Zealand and is thus a valuable resource for managers, researchers and the public that will guide the management and conservation of seafloor communities. The atlas of seabed biodiversity for Aotearoa New Zealand is freely accessible via the open-Access database Zenodo under 10.5281/zenodo.7083642 (Stephenson et al., 2022)

Comparative evaluation of the treatment efficacy of suberoylanilide hydroxamic acid (SAHA) and paclitaxel in ovarian cancer cell lines and primary ovarian cancer cells from patients

BACKGROUND: In most patients with ovarian cancer, diagnosis occurs after the tumour has disseminated beyond the ovaries. In these cases, post-surgical taxane/platinum combination chemotherapy is the "gold standard". However, most of the patients experience disease relapse and eventually die due to the emergence of chemotherapy resistance. Histone deacetylase inhibitors are novel anticancer agents that hold promise to improve patient outcome. METHODS: We compared a prototypic histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), and paclitaxel for their treatment efficacy in ovarian cancer cell lines and in primary patient-derived ovarian cancer cells. The primary cancer cells were isolated from malignant ascites collected from five patients with stage III ovarian carcinomas. Cytotoxic activities were evaluated by Alamar Blue assay and by caspase-3 activation. The ability of SAHA to kill drug-resistant 2780AD cells was also assessed. RESULTS: By employing the cell lines OVCAR-3, SK-OV-3, and A2780, we established SAHA at concentrations of 1 to 20 μM to be as efficient in inducing cell death as paclitaxel at concentrations of 3 to 300 nM. Consequently, we treated the patient-derived cancer cells with these doses of the drugs. All five isolates were sensitive to SAHA, with cell killing ranging from 21% to 63% after a 72-h exposure to 20 μM SAHA, while four of them were resistant to paclitaxel (i.e., <10% cell death at 300 nM paclitaxel for 72 hours). Likewise, treatment with SAHA led to an increase in caspase-3 activity in all five isolates, whereas treatment with paclitaxel had no effect on caspase-3 activity in three of them. 2780AD cells were responsive to SAHA but resistant to paclitaxel. CONCLUSION: These ex vivo findings raise the possibility that SAHA may prove effective in the treatment of paclitaxel-resistant ovarian cancer in vivo

Marine Biodiversity of Aotearoa New Zealand

The marine-biodiversity assessment of New Zealand (Aotearoa as known to Māori) is confined to the 200 nautical-mile boundary of the Exclusive Economic Zone, which, at 4.2 million km2, is one of the largest in the world. It spans 30° of latitude and includes a high diversity of seafloor relief, including a trench 10 km deep. Much of this region remains unexplored biologically, especially the 50% of the EEZ deeper than 2,000 m. Knowledge of the marine biota is based on more than 200 years of marine exploration in the region. The major oceanographic data repository is the National Institute of Water and Atmospheric Research (NIWA), which is involved in several Census of Marine Life field projects and is the location of the Southwestern Pacific Regional OBIS Node; NIWA is also data manager and custodian for fisheries research data owned by the Ministry of Fisheries. Related data sources cover alien species, environmental measures, and historical information. Museum collections in New Zealand hold more than 800,000 registered lots representing several million specimens. During the past decade, 220 taxonomic specialists (85 marine) from 18 countries have been engaged in a project to review New Zealand's entire biodiversity. The above-mentioned marine information sources, published literature, and reports were scrutinized to give the results summarized here for the first time (current to 2010), including data on endemism and invasive species. There are 17,135 living species in the EEZ. This diversity includes 4,315 known undescribed species in collections. Species diversity for the most intensively studied phylum-level taxa (Porifera, Cnidaria, Mollusca, Brachiopoda, Bryozoa, Kinorhyncha, Echinodermata, Chordata) is more or less equivalent to that in the ERMS (European Register of Marine Species) region, which is 5.5 times larger in area than the New Zealand EEZ. The implication is that, when all other New Zealand phyla are equally well studied, total marine diversity in the EEZ may be expected to equal that in the ERMS region. This equivalence invites testable hypotheses to explain it. There are 177 naturalized alien species in New Zealand coastal waters, mostly in ports and harbours. Marine-taxonomic expertise in New Zealand covers a broad number of taxa but is, proportionately, at or near its lowest level since the Second World War. Nevertheless, collections are well supported by funding and are continually added to. Threats and protection measures concerning New Zealand's marine biodiversity are commented on, along with potential and priorities for future research

Comparative effectiveness of antihypertensive medication for primary prevention of cardiovascular disease: systematic review and multiple treatments meta-analysis

Background: We conducted a systematic review of evidence from randomized controlled trials to answer the following research question: What are the relative effects of different classes of antihypertensive drugs in reducing the incidence of cardiovascular disease outcomes for healthy people at risk of cardiovascular disease? Methods: We searched MEDLINE, EMBASE, AMED (up to February 2011) and CENTRAL (up to May 2009), and reference lists in recent systematic reviews. Titles and abstracts were assessed for relevance and those potentially fulfilling our inclusion criteria were then assessed in full text. Two reviewers made independent assessments at each step. We selected the following main outcomes: total mortality, myocardial infarction and stroke. We also report on angina, heart failure and incidence of diabetes. We conducted a multiple treatments meta-analysis using random-effects models. We assessed the quality of the evidence using the GRADE-instrument. Results: We included 25 trials. Overall, the results were mixed, with few significant dif-ferences, and with no drugclass standing out as superior across multiple outcomes. The only significant finding for total mortality based on moderate to high quality evidence was that beta-blockers (atenolol) were inferior to angiotensin receptor blockers (ARB) (relative risk (RR) 1.14; 95% credibility interval (CrI) 1.02 to 1.28). Angiotensin converting enzyme (ACE)- inhibitors came out inferior to calcium-channel blockers (CCB) regarding stroke-risk (RR 1.19; 1.03 to 1.38), but superior regarding risk of heart failure (RR 0.82; 0.69 to 0.94), both based on moderate quality evidence. Diuretics reduced the risk of myocardial infarction compared to beta-blockers (RR 0.82; 0.68 to 0.98), and lowered the risk of heart failure compared to CCB (RR 0.73; 0.62 to 0.84), beta-blockers (RR 0.73; 0.54 to 0.96), and alpha-blockers (RR 0.51; 0.40 to 0.64). The risk of diabetes increased with diuretics compared to ACE-inhibitors (RR 1.43; 1.12 to 1.83) and CCB (RR 1.27; 1.05 to 1.57). Conclusion: Based on the available evidence, there seems to be little or no difference between commonly used blood pressure lowering medications for primary prevention of cardiovascular disease. Beta-blockers (atenolol) and alpha-blockers may not be first-choice drugs as they were the only drug-classes that were not significantly superior to any other, for any outcomes

E2F1 Mediated Apoptosis Induced by the DNA Damage Response Is Blocked by EBV Nuclear Antigen 3C in Lymphoblastoid Cells

EBV latent antigen EBNA3C is indispensible for in vitro B-cell immortalization resulting in continuously proliferating lymphoblastoid cell lines (LCLs). EBNA3C was previously shown to target pRb for ubiquitin-proteasome mediated degradation, which facilitates G1 to S transition controlled by the major transcriptional activator E2F1. E2F1 also plays a pivotal role in regulating DNA damage induced apoptosis through both p53-dependent and -independent pathways. In this study, we demonstrate that in response to DNA damage LCLs knocked down for EBNA3C undergo a drastic induction of apoptosis, as a possible consequence of both p53- and E2F1-mediated activities. Importantly, EBNA3C was previously shown to suppress p53-induced apoptosis. Now, we also show that EBNA3C efficiently blocks E2F1-mediated apoptosis, as well as its anti-proliferative effects in a p53-independent manner, in response to DNA damage. The N- and C-terminal domains of EBNA3C form a stable pRb independent complex with the N-terminal DNA-binding region of E2F1 responsible for inducing apoptosis. Mechanistically, we show that EBNA3C represses E2F1 transcriptional activity via blocking its DNA-binding activity at the responsive promoters of p73 and Apaf-1 apoptosis induced genes, and also facilitates E2F1 degradation in an ubiquitin-proteasome dependent fashion. Moreover, in response to DNA damage, E2F1 knockdown LCLs exhibited a significant reduction in apoptosis with higher cell-viability. In the presence of normal mitogenic stimuli the growth rate of LCLs knockdown for E2F1 was markedly impaired; indicating that E2F1 plays a dual role in EBV positive cells and that active engagement of the EBNA3C-E2F1 complex is crucial for inhibition of DNA damage induced E2F1-mediated apoptosis. This study offers novel insights into our current understanding of EBV biology and enhances the potential for development of effective therapies against EBV associated B-cell lymphomas