155 research outputs found
Deposition, persistence and turnover of pollutants: First results from the EU project AquaTerra for selected river basins and aquifers
Transient parkinsonism in isolated extrapontine myelinolysis
Extrapontine myelinolysis (EPM) is a rare cause of parkinsonism. In this case report, we describe a 63-year-old woman with parkinsonism due to EPM after correction of hyponatremia. During a 4-year follow-up, both the clinical features of parkinsonism and the changes on magnetic resonance imaging resolved. Parkinsonism due to EPM should be recognized as it has a good prognosis
emerging perspectives for flood risk assessment and management
Flood estimation and flood management have traditionally been the domain of
hydrologists, water resources engineers and statisticians, and disciplinary
approaches abound. Dominant views have been shaped; one example is the
catchment perspective: floods are formed and influenced by the interaction of
local, catchment-specific characteristics, such as meteorology, topography and
geology. These traditional views have been beneficial, but they have a narrow
framing. In this paper we contrast traditional views with broader perspectives
that are emerging from an improved understanding of the climatic context of
floods. We come to the following conclusions: (1) extending the traditional
system boundaries (local catchment, recent decades, hydrological/hydraulic
processes) opens up exciting possibilities for better understanding and
improved tools for flood risk assessment and management. (2) Statistical
approaches in flood estimation need to be complemented by the search for the
causal mechanisms and dominant processes in the atmosphere, catchment and
river system that leave their fingerprints on flood characteristics. (3)
Natural climate variability leads to time-varying flood characteristics, and
this variation may be partially quantifiable and predictable, with the
perspective of dynamic, climate-informed flood risk management. (4) Efforts
are needed to fully account for factors that contribute to changes in all
three risk components (hazard, exposure, vulnerability) and to better
understand the interactions between society and floods. (5) Given the global
scale and societal importance, we call for the organization of an
international multidisciplinary collaboration and data-sharing initiative to
further understand the links between climate and flooding and to advance flood
research
Floods and climate: emerging perspectives for flood risk assessment and management
Flood estimation and flood management have traditionally been the domain of
hydrologists, water resources engineers and statisticians, and disciplinary
approaches abound. Dominant views have been shaped; one example is the
catchment perspective: floods are formed and influenced by the interaction
of local, catchment-specific characteristics, such as meteorology,
topography and geology. These traditional views have been beneficial, but
they have a narrow framing. In this paper we contrast traditional views with
broader perspectives that are emerging from an improved understanding of the
climatic context of floods. We come to the following conclusions: (1) extending the traditional
system boundaries (local catchment, recent decades, hydrological/hydraulic
processes) opens up exciting possibilities for better understanding and
improved tools for flood risk assessment and management. (2) Statistical
approaches in flood estimation need to be complemented by the search for the
causal mechanisms and dominant processes in the atmosphere, catchment and
river system that leave their fingerprints on flood characteristics.
(3) Natural climate variability leads to time-varying flood characteristics, and
this variation may be partially quantifiable and predictable, with the
perspective of dynamic, climate-informed flood risk management.
(4) Efforts are needed to fully account for factors that contribute to changes
in all three risk components (hazard, exposure, vulnerability) and to
better understand the interactions between society and floods. (5) Given the
global scale and societal importance, we call for the organization of an
international multidisciplinary collaboration and data-sharing initiative to
further understand the links between climate and flooding and to advance
flood research
Perioperative oxygen fraction – effect on surgical site infection and pulmonary complications after abdominal surgery: a randomized clinical trial. Rationale and design of the PROXI-Trial
<p>Abstract</p> <p>Background</p> <p>A high perioperative inspiratory oxygen fraction may reduce the risk of surgical site infections, as bacterial eradication by neutrophils depends on wound oxygen tension. Two trials have shown that a high perioperative inspiratory oxygen fraction (Fi<smcaps>O</smcaps><sub>2 </sub>= 0.80) significantly reduced risk of surgical site infections after elective colorectal surgery, but a third trial was stopped early because the frequency of surgical site infections was more than doubled in the group receiving Fi<smcaps>O</smcaps><sub>2 </sub>= 0.80. It has not been settled if a high inspiratory oxygen fraction increases the risk of pulmonary complications, such as atelectasis, pneumonia and respiratory failure. The aim of our trial is to assess the potential benefits and harms of a high perioperative oxygen fraction in patients undergoing abdominal surgery.</p> <p>Methods and design</p> <p>The PROXI-Trial is a randomized, patient- and assessor blinded trial of perioperative supplemental oxygen in 1400 patients undergoing acute or elective laparotomy in 14 Danish hospitals. Patients are randomized to receive either 80% oxygen (Fi<smcaps>O</smcaps><sub>2 </sub>= 0.80) or 30% oxygen (Fi<smcaps>O</smcaps><sub>2 </sub>= 0.30) during surgery and for the first 2 postoperative hours. The primary outcome is surgical site infection within 14 days. The secondary outcomes are: atelectasis, pneumonia, respiratory failure, re-operation, mortality, duration of postoperative hospitalization, and admission to intensive care unit. The sample size allows detection of a 33% relative risk reduction in the primary outcome with 80% power.</p> <p>Discussion</p> <p>This trial assesses benefits and harms of a high inspiratory oxygen fraction, and the trial may be generalizable to a general surgical population undergoing laparotomy.</p> <p>Trial registration</p> <p>ClinicalTrials.gov identifier: NCT00364741.</p
Diagnosis of inflammatory demyelination in biopsy specimens: a practical approach
Multiple sclerosis is the most frequent demyelinating disease in adults. It is characterized by demyelination, inflammation, gliosis and a variable loss of axons. Clinically and histologically, it shares features with other demyelinating and/or inflammatory CNS diseases. Diagnosis of an inflammatory demyelinating disease can be challenging, especially in small biopsy specimens. Here, we summarize the histological hallmarks and most important neuropathological differential diagnoses of early MS, and provide practical guidelines for the diagnosis of inflammatory demyelinating diseases
The life and scientific work of William R. Evitt (1923-2009)
Occasionally (and fortunately), circumstances and timing combine to allow an individual, almost singlehandedly, to generate a paradigm shift in his or her chosen field of inquiry. William R. (‘Bill’) Evitt (1923-2009) was such a person. During his career as a palaeontologist, Bill Evitt made lasting and profound contributions to the study of both dinoflagellates and trilobites. He had a distinguished, long and varied career, researching first trilobites and techniques in palaeontology before moving on to marine palynomorphs. Bill is undoubtedly best known for his work on dinoflagellates, especially their resting cysts. He worked at three major US universities and spent a highly significant period in the oil industry. Bill's early profound interest in the natural sciences was actively encouraged both by his parents and at school. His alma mater was Johns Hopkins University where, commencing in 1940, he studied chemistry and geology as an undergraduate. He quickly developed a strong vocation in the earth sciences, and became fascinated by the fossiliferous Lower Palaeozoic strata of the northwestern United States. Bill commenced a PhD project on silicified Middle Ordovician trilobites from Virginia in 1943. His doctoral research was interrupted by military service during World War II; Bill served as an aerial photograph interpreter in China in 1944 and 1945, and received the Bronze Star for his excellent work. Upon demobilisation from the US Army Air Force, he resumed work on his PhD and was given significant teaching duties at Johns Hopkins, which he thoroughly enjoyed. He accepted his first professional position, as an instructor in sedimentary geology, at the University of Rochester in late 1948. Here Bill supervised his first two graduate students, and shared a great cameraderie with a highly motivated student body which largely comprised World War II veterans. At Rochester, Bill continued his trilobite research, and was the editor of the Journal of Paleontology between 1953 and 1956. Seeking a new challenge, he joined the Carter Oil Company in Tulsa, Oklahoma, during 1956. This brought about an irrevocable realignment of his research interests from trilobites to marine palynology. He undertook basic research on aquatic palynomorphs in a very well-resourced laboratory under the direction of one of his most influential mentors, William S. ‘Bill’ Hoffmeister. Bill Evitt visited the influential European palynologists Georges Deflandre and Alfred Eisenack during late 1959 and, while in Tulsa, first developed several groundbreaking hypotheses. He soon realised that the distinctive morphology of certain fossil dinoflagellates, notably the archaeopyle, meant that they represent the resting cyst stage of the life cycle. The archaeopyle clearly allows the excystment of the cell contents, and comprises one or more plate areas. Bill also concluded that spine-bearing palynomorphs, then called hystrichospheres, could be divided into two groups. The largely Palaeozoic spine-bearing palynomorphs are of uncertain biological affinity, and these were termed acritarchs. Moreover, he determined that unequivocal dinoflagellate cysts are all Mesozoic or younger, and that the fossil record of dinoflagellates is highly selective. Bill was always an academic at heart and he joined Stanford University in 1962, where he remained until retiring in 1988. Bill enjoyed getting back into teaching after his six years in industry. During his 26-year tenure at Stanford, Bill continued to revolutionise our understanding of dinoflagellate cysts. He produced many highly influential papers and two major textbooks. The highlights include defining the acritarchs and comprehensively documenting the archaeopyle, together with highly detailed work on the morphology of Nannoceratopsis and Palaeoperidinium pyrophorum using the scanning electron microscope. Bill supervised 11 graduate students while at Stanford University. He organised the Penrose Conference on Modern and Fossil Dinoflagellates in 1978, which was so successful that similar meetings have been held about every four years since that inaugural symposium. Bill also taught many short courses on dinoflagellate cysts aimed at the professional community. Unlike many eminent geologists, Bill actually retired from actively working in the earth sciences. His full retirement was in 1988; after this he worked on only a small number of dinoflagellate cyst projects, including an extensive paper on the genus Palaeoperidinium
A transcriptome-based classifier to identify developmental toxicants by stem cell testing: design, validation and optimization for histone deacetylase inhibitors
A Review of Flood-Related Storage and Remobilization of Heavy Metal Pollutants in River Systems
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