83 research outputs found

    The Lagoon at Caroline/Millennium Atoll, Republic of Kiribati: Natural History of a Nearly Pristine Ecosystem

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    A series of surveys were carried out to characterize the physical and biological parameters of the Millennium Atoll lagoon during a research expedition in April of 2009. Millennium is a remote coral atoll in the Central Pacific belonging to the Republic of Kiribati, and a member of the Southern Line Islands chain. The atoll is among the few remaining coral reef ecosystems that are relatively pristine. The lagoon is highly enclosed, and was characterized by reticulate patch and line reefs throughout the center of the lagoon as well as perimeter reefs around the rim of the atoll. The depth reached a maximum of 33.3 m in the central region of the lagoon, and averaged between 8.8 and 13.7 m in most of the pools. The deepest areas were found to harbor large platforms of Favia matthaii, which presumably provided a base upon which the dominant corals (Acropora spp.) grew to form the reticulate reef structure. The benthic algal communities consisted mainly of crustose coralline algae (CCA), microfilamentous turf algae and isolated patches of Halimeda spp. and Caulerpa spp. Fish species richness in the lagoon was half of that observed on the adjacent fore reef. The lagoon is likely an important nursery habitat for a number of important fisheries species including the blacktip reef shark and Napoleon wrasse, which are heavily exploited elsewhere around the world but were common in the lagoon at Millennium. The lagoon also supports an abundance of giant clams (Tridacna maxima). Millennium lagoon provides an excellent reference of a relatively undisturbed coral atoll. As with most coral reefs around the world, the lagoon communities of Millennium may be threatened by climate change and associated warming, acidification and sea level rise, as well as sporadic local resource exploitation which is difficult to monitor and enforce because of the atoll's remote location. While the remote nature of Millennium has allowed it to remain one of the few nearly pristine coral reef ecosystems in the world, it is imperative that this ecosystem receives protection so that it may survive for future generations

    How many human proteoforms are there?

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    Despite decades of accumulated knowledge about proteins and their post-translational modifications (PTMs), numerous questions remain regarding their molecular composition and biological function. One of the most fundamental queries is the extent to which the combinations of DNA-, RNA- and PTM-level variations explode the complexity of the human proteome. Here, we outline what we know from current databases and measurement strategies including mass spectrometry-based proteomics. In doing so, we examine prevailing notions about the number of modifications displayed on human proteins and how they combine to generate the protein diversity underlying health and disease. We frame central issues regarding determination of protein-level variation and PTMs, including some paradoxes present in the field today. We use this framework to assess existing data and to ask the question, "How many distinct primary structures of proteins (proteoforms) are created from the 20,300 human genes?" We also explore prospects for improving measurements to better regularize protein-level biology and efficiently associate PTMs to function and phenotype

    Global change effects on plant communities are magnified by time and the number of global change factors imposed

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    Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously

    Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

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    Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P &lt; 0.001) and PARP inhibitor therapy (P &lt; 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P &lt; 0.018) and WEE1 inhibitor (P &lt; 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P &lt; 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

    Neurotropic virus infections as the cause of immediate and delayed neuropathology

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    The Balance Sheet of the Farming Sector, 1970

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    Farm assets totaled 311.4billiononJanuary1,1970,whilefarmdebtoutstandingreached311.4 billion on January 1, 1970, while farm debt outstanding reached 58.1 billion leaving farm proprietors' equities of 253.3billion.Theratiooffarmdebttovalueofassetswas18.7percent,up0.4pointfromayearearlier.Advancesinthevalueoffarmrealestatemadeuphalfof1969′s253.3 billion. The ratio of farm debt to value of assets was 18.7 percent, up 0.4 point from a year earlier. Advances in the value of farm real estate made up half of 1969's 12.3 billion gain in farm asset value. Higher values for livestock and poultry mainly accounted for the rest of asset growth. Farm non-real estate debt grew 2.2billionduring1969comparedwith2.2 billion during 1969 compared with 1.3 billion for farm real estate debt, the latter figure indicating farmers’ reluctance to enter long-term loan contracts at the high interest rates prevailing last year. Regionally, the Corn Belt had the highest value of farm assets but farm debt was also highest there. As a group, farmers who had gross sales of 20,000to20,000 to 39,999 during 1969 owned the largest share of farm assets and owed the largest proportion of farm debt

    The Balance Sheet of the Farming Sector, 1971

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    Farm proprietors' assets totaled 318.9billiononJanuary1,1971,whilefarmdebtoutstandingtotaled318.9 billion on January 1, 1971, while farm debt outstanding totaled 61.1 billion, leaving equities of 257.8billion.Theratiooffarmdebttovalueofassetswas19.2percent,upfrom18.8percentayearearlier.Advancesinthevaluesoffarmrealestatemadeupoverhalfof1970′s257.8 billion. The ratio of farm debt to value of assets was 19.2 percent, up from 18.8 percent a year earlier. Advances in the values of farm real estate made up over half of 1970's 9.3 billion gain in farm asset value; higher value of machinery and motor vehicles largely accounted for remaining growth. Farm non-real estate debt grew 2.7billionduring1970,comparedwith2.7 billion during 1970, compared with 1.1 billion for farm real estate debt. Farmers were reluctant to take long-term real estate loans at the prevailing high interest rates. Realized net farm income dropped to $15.6 billion-down 6.5 percent from 1969
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