90 research outputs found

    Holding States Accountable for Harmful Algal Blooms: Florida\u27s Water Crisis in Focus

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    Scientists generally agree that agricultural runoff is a principal source of nutrient pollution in the United States. Intensive agricultural practices have resulted in decades of phosphorus and nitrogen accumulating in the natural system which continue to contribute substantially to nutrients entering watersheds. Coupled with failed water quality control measures, this water pollution has led to some of the worst harmful algal blooms (HABs) in recorded history. These nonpoint sources need to be addressed to restore and protect water quality. Florida’s Lake Okeechobee watershed provides an apt case study. Commonly referred to as the “liquid heart” of the Everglades, the lake has experienced a proliferation of large scale HABs, sometimes covering an area of more than 500 square miles and observable from space. These HABs wreak havoc on the lake’s ecology. When the lake reaches water levels that pose a flooding risk to communities to the south, the United States Army Corps of Engineers discharges billions of gallons of algae and nutrient laden water to the Caloosahatchee and St. Lucie estuaries on the west and east coasts. These algae blooms cause additional harm and destruction to wildlife in these systems and pose a threat to human health and local economies. This Article seeks to provide water quality advocates, lawmakers, and government agencies with a regulatory and policy framework for addressing HABs in their states, using Lake Okeechobee and its coastal estuaries as a case study

    Dispersants: The Lesser Of Two Evils Or A Cure Worse Than The Disease?

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    The April 20, 2010, BP oil spill is widely regarded as the nation’s worst environmental disaster. The explosion of the Deepwater Horizon oil rig resulted in the death of eleven crewmen, and thousands of fish, sea turtles, birds, and marine mammals. The federal government estimates that 4.9 million barrels (or 205.8 million gallons) of oil spilled into the Gulf of Mexico from the rogue well. In addition to the direct effect on wildlife from the spilled oil, which includes reduced ability to regulate temperature, forage, and nest, the unprecedented application of dispersants also likely impacted wildlife. During the oil spill, BP released roughly 1.84 million gallons of dispersants into the Gulf, 1.07 million gallons to the surface and 771,000 subsea. The Environmental Protection Agency (EPA) approved these measures despite its admission that no one fully knew the environmental effects of the dispersants, particularly at such great depths or volumes. Lisa Jackson, EPA administrator, called her decision to approve BP’s subsea dispersant use the hardest decision she ever made. As days turned to weeks and the oil continued to spill, it became obvious that both BP and the government were woefully unprepared to respond to a spill of this magnitude. The horror and chaos of the oil spill put the government in the awkward position of leading the efforts to respond to the spill while relying on industry resources and expertise. This also resulted in a tug-of-war within the Obama Administration between its enforcement and regulation roles and its need to cooperate with BP in order to stop the flow of oil and recover from the spill. The use of subsea dispersants most clearly exemplified this conflict as the government’s lack of knowledge about the effects of dispersants made it almost impossible for it to fulfill its legal duty to protect the nation’s waters and wildlife from pollutants. Two U.S. federal laws, the Clean Water Act (CWA) and the Endangered Species Act (ESA), contain provisions that specifically ensure that dispersant approval and use will not jeopardize imperiled wildlife and the resources on which they depend. In light of the general lack of knowledge regarding the effects of dispersants used in response to the Deepwater Horizon oil spill, and the harm they may have caused, it has become evident that these two environmental laws, their implementation, or both, were inadequate to safeguard the environment and wildlife from the disaster response. This Article examines the use of dispersants in response to the BP oil spill. The authors describe the ways in which the CWA and the ESA authorize the EPA to regulate the use of dispersants and suggest how the regulation of dispersants could be strengthened. Part II discusses the development of contingency plans for oil spills in the Gulf of Mexico and the pre-spill consultation process for dispersants’ effects on wildlife. Part III describes BP’s dispersant use in response to the Deepwater Horizon oil spill and recent scientific research identifying potential effects on the ocean and marine wildlife. Part IV discusses lessons learned from the oil spill and concludes that future preparedness will require better agency implementation or even legislative action

    DRAM-1 is required for mTORC1 activation by facilitating lysosomal amino acid efflux

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    Sensing nutrient availability is essential for appropriate cellular growth, and mTORC1 is a major regulator of this process. Mechanisms causing mTORC1 activation are, however, complex and diverse. We report here an additional important step in the activation of mTORC1, which regulates the efflux of amino acids from lysosomes into the cytoplasm. This process requires DRAM-1, which binds the membrane carrier protein SCAMP3 and the amino acid transporters SLC1A5 and LAT1, directing them to lysosomes and permitting efficient mTORC1 activation. Consequently, we show that loss of DRAM-1 also impacts pathways regulated by mTORC1, including insulin signaling, glycemic balance, and adipocyte differentiation. Interestingly, although DRAM-1 can promote autophagy, this effect on mTORC1 is autophagy independent, and autophagy only becomes important for mTORC1 activation when DRAM-1 is deleted. These findings provide important insights into mTORC1 activation and highlight the importance of DRAM-1 in growth control, metabolic homeostasis, and differentiation

    Fetal Demise and Failed Antibody Therapy During Zika Virus Infection of Pregnant Macaques

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    Zika virus (ZIKV) infection of pregnant women is associated with pathologic complications of fetal development. Here, we infect pregnant rhesus macaques (Macaca mulatta) with a minimally passaged ZIKV isolate from Rio de Janeiro, where a high rate of fetal development complications was observed. The infection of pregnant macaques with this virus results in maternal viremia, virus crossing into the amniotic fluid (AF), and in utero fetal deaths. We also treated three additional ZIKV-infected pregnant macaques with a cocktail of ZIKV-neutralizing human monoclonal antibodies (nmAbs) at peak viremia. While the nmAbs can be effective in clearing the virus from the maternal sera of treated monkeys, it is not sufficient to clear ZIKV from AF. Our report suggests that ZIKV from Brazil causes fetal demise in non-human primates (NHPs) without additional mutations or confounding co-factors. Treatment with a neutralizing anti-ZIKV nmAb cocktail is insufficient to fully stop vertical transmission

    Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes

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    Oral–facial–digital syndromes (OFDS) gather rare genetic disorders characterised by facial, oral and digital abnormalities associated with a wide range of additional features (polycystic kidney disease, cerebral malformations and several others) to delineate a growing list of OFDS subtypes. The most frequent, OFD type I, is caused by a heterozygous mutation in the OFD1 gene encoding a centrosomal protein. The wide clinical heterogeneity of OFDS suggests the involvement of other ciliary genes. For 15 years, we have aimed to identify the molecular bases of OFDS. This effort has been greatly helped by the recent development of whole-exome sequencing (WES). Here, we present all our published and unpublished results for WES in 24 cases with OFDS. We identified causal variants in five new genes (C2CD3, TMEM107, INTU, KIAA0753 and IFT57) and related the clinical spectrum of four genes in other ciliopathies (C5orf42, TMEM138, TMEM231 and WDPCP) to OFDS. Mutations were also detected in two genes previously implicated in OFDS. Functional studies revealed the involvement of centriole elongation, transition zone and intraflagellar transport defects in OFDS, thus characterising three ciliary protein modules: the complex KIAA0753-FOPNL-OFD1, a regulator of centriole elongation; the Meckel-Gruber syndrome module, a major component of the transition zone; and the CPLANE complex necessary for IFT-A assembly. OFDS now appear to be a distinct subgroup of ciliopathies with wide heterogeneity, which makes the initial classification obsolete. A clinical classification restricted to the three frequent/well-delineated subtypes could be proposed, and for patients who do not fit one of these three main subtypes, a further classification could be based on the genotype

    Novel Methylated Biomarkers and a Robust Assay to Detect Circulating Tumor DNA in Metastatic Breast Cancer

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    The ability to consistently detect cell-free tumor-specific DNA in peripheral blood of patients with metastatic breast cancer provides the opportunity to detect changes in tumor burden and to monitor response to treatment. We developed cMethDNA, a quantitative multiplexed methylation-specific PCR assay for a panel of ten genes, consisting of novel and known breast cancer hypermethylated markers identified by mining our previously reported study of DNA methylation patterns in breast tissue (103 cancer, 21 normal on the Illumina HumanMethylation27 Beadchip) and then validating the 10-gene panel in a TCGA breast cancer methylome database. For cMethDNA, a fixed physiological level (50 copies) of artificially constructed, standard non-human reference DNA specific for each gene is introduced into in a constant volume of serum (300 μl) prior to purification of the DNA, facilitating a sensitive, specific, robust and quantitative assay of tumor DNA, with broad dynamic range. Cancer-specific methylated DNA was detected in Training (28 normal, 24 cancer) and Test (27 normal, 33 cancer) sets of recurrent Stage 4 patient sera with a sensitivity of 91% and a specificity of 96% in the test set. In a pilot study, cMethDNA assay faithfully reflected patient response to chemotherapy (N = 29). A core methylation signature present in the primary breast cancer was retained in serum and metastatic tissues collected at autopsy 2–11 years after diagnosis of the disease. Together, our data suggest that the cMethDNA assay can detect advanced breast cancer, and monitor tumor burden and treatment response in women with metastatic breast cancer

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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