453 research outputs found
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Effects of pharmaceutical wastes on growth of microalgae
The purpose of this work was to assay samples of waste material from Puerto Rican pharmaceutical industries for inhibition of growth of algae. Two samples (noted as I and II) supplied to us were tested for toxicity to six microalgae. The test organisms, two blue-green algae, two green algae, and two diatoms [r]epresent three major divisions of algae.University of Texas Marine Science InstituteMarine Scienc
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Biodegradation of aromatic compounds by high latitude phytoplankton
"It was the purpose of the work undertaken to bring into pure culture representative diatoms from the Cook Inlet and the ice-edge in the Bering Sea and to examine their capacity for the oxidation of aromatic compounds using naphthalene as a model substrate. Three diatoms from the Cook Inlet (Kasitsna Bay) were shown to metabolize naphthalene at 6 or 12°C to 1-naphthol and other unidentified ethyl acetate and water-soluble products. Likewise, three diatoms isolated from samples collected at the ice-edge in the Bering Sea also formed small amounts of 1-naphthol from naphthalene when incubated in the light at 0 or 10°C. We have not been able to rigorously prove that any algal cell, be it a blue-green alga, a green alga, or a diatom can metabolize (1-¹⁴C) naphthalene far enough to produce ¹⁴CO₂. However, if we assume a stoichiometery of one 1-naphthol in the algae equivalent to one CO₂ in bacteria, then for mesophilic algae, the rate of 1-naphthol production is roughly estimated as 10% of the in situ marine potential, and perhaps higher if only the photic zone is considered. We have as yet, no corresponding values for rate of 1-naphthol formation from naphthalene by cold-adapted or psychrophilic diatom cultures, however, it seems reasonable to suggest that algal aromatic transformations may also be a significant fraction of bacterial activity in cold environments. In addition to studies on the oxidation of naphthalene we have also examined the sensitivity of the Bering Sea psychrophilic diatoms to crude oil samples from Cook Inlet and Prudhoe Bay. The results with pure cultures indicate that the toxicity of crude oil was enhanced in psychrophilic diatoms growing at O°C or 10°C as compared to previous studies with mesophilic forms. There are several important consequences of the results for Alaskan OCS oil and gas development. It is now clear that pure cultures of diatoms isolated from either the lower Cook Inlet or from the ice-edge in the Bering Sea can oxidize aromatic compounds such as naphthalene. Whether the metabolites persist through the food chain and will be more or less toxic than naphthalene itself is not known. The results with naphthalene also imply that the photic zone can be an important sink for aromatic hydrocarbon transformations. There are certainly differences among microalgae in the capacity to oxidize naphthalene. It seems prudent, therefore, to insure, via monitoring, that accidental introduction of aromatic compounds in Alaskan waters does not cause a selective or enrichment effect on existing phytoplankton populations. A second area of environmental concern is the suggestion of an enhanced crude oil toxicity in slower growing psychrophilic diatoms as compared to their mesophilic cousins. Crude oil spills near or under the sea ice may severely impact primary productivity, and thereby higher tropic level.Final report RD/MPF24-Effects-675April 30, 1982Marine Scienc
Nerve-preserving aortoiliac reconstruction surgery: Anatomical study and surgical approach
AbstractObjective: Dysfunctional ejaculation and, to a lesser extent, dysfunctional erection caused by disruption of efferent sympathetic pathways is a common complication after aortoiliac reconstruction surgery. The aim was to give an anatomic motivation for a nerve-preserving approach on the basis of right-sided unilateral disruption of lumbar splanchnic nerves. Methods: Anatomic and microscopic analysis of preaortic and para-aortic retroperitoneal regions in human cadavers was performed. Anatomic analysis was conducted of two aortoiliac reconstruction operations performed on human cadavers; one was performed according to a single-blind procedure, the second with a modified procedure. Results: The lumbar splanchnic nerves supplying the superior hypogastric plexus from the right side were found to be less voluminous than the left-sided ones. The superior hypogastric plexus was found slightly shifted to the left of the midsagittal plane across the abdominal aorta and its bifurcation. Microscopic analysis revealed a thin fascia between the aorta and the subperitoneal tissue compartment. This fascia was used as a plain of dissection to mobilize the preaortic nerve-plexuses without damage from the aortic wall. Analysis of the specimens operated on showed a significant difference in nerve disruption. The standard procedure caused total disruption of the superior hypogastric plexus and extensive disruption of the inferior mesenteric plexus. The modified procedure only caused right-sided unilateral disruption of lumbar splanchnic nerves. Conclusion: The autonomic nerves supplying the bladder neck, the vas deferens, and the prostate are closely related to the abdominal aorta and its bifurcation. Right-sided unilateral disruption of lumbar splanchnic nerves without further damage to nervous structures would ensure at least one functional sympathetic pathway remaining after aortoiliac reconstruction surgery. (J Vasc Surg 2001;33:983-9.
Apollo to Artemis: Mining 50-Year Old Records to Inform Future Human Lunar Landing Systems
Under the Artemis lunar exploration program, NASA is committed to landing American astronauts on the moon by 2024. While NASAs new Space Launch System rocket and Orion capsule will carry astronauts from Earth to the Gateway, the human lunar landing system has not yet been fully defined. As in the Apollo program, there are concerns for vehicle weight and internal volume such that seats may not be desirable, and standing during lunar descent and ascent may be a preferred engineering solution. With such a design, astronauts will experience +GZ (head-to-foot) accelerations during capsule accelerations, and it is unclear whether spaceflight deconditioned astronauts can tolerate these. Apollo astronauts stood during lunar descent and ascent, and the data contained in the early program records for those missions represent a unique resource that may provide insights to the cardiovascular stress associated with this human landing system design
Protein microparticles visualize the contact network and rigidity onset in the gelation of model proteins
Colonoscopy Screening in the US Astronaut Corps
Historically, colonoscopy screenings for astronauts have been conducted to ensure that astronauts are in good health for space missions. This data has been identified as being useful for determining appropriate occupational surveillance targets and requirements. Colonoscopies in the astronaut corps can be used for: (a) Assessing overall colon health, (b) A point of reference for future tests in current and former astronauts, (c) Following-up and tracking rates of colorectal cancer and polyps; and (d) Comparison to military and other terrestrial populations. In 2003, medical screening requirements for the active astronaut corps changed to require less frequent colonoscopies. Polyp removal during a colonoscopy is an intervention that prevents the polyp from potentially developing into cancer and decreases the individual's risk for colon cancer
Multilateral Biomedical Data Sharing in the One-year Joint US-Russian Mission on the International Space Station
The One Year Mission (1YM) by two astronauts on the International Space Station (ISS), starting in March 2015, offers a unique opportunity to expand multilateral collaboration by sharing data and resources among the partner agencies in preparation for planned space exploration missions beyond low Earth orbit. Agreements and protocols will be established for the collection, distribution, analysis and reporting of both research and clinical data. Data will be shared between the agencies sponsoring the investigators, and between the research and clinical medicine communities where common interests are identified. The assignment of only two astronauts, one Russian and the other American, to the 1YM necessitated creativity in bilateral efforts to maximize the biomedical return from the opportunity. Addition of Canadian, European and Japanese investigations make the effort even more integrative. There will be three types of investigations: joint, crossparticipation and dataexchange. The joint investigations have US and Russian coprincipal investigators, and the data acquired will be their common responsibility. The other two types must develop data sharing agreements and processes specific to their needs. A multilateral panel of ISS partner space agencies will develop policies for international exchange of scientific information to meet their science objectives and priorities. They will promote archiving of space flight data and will inform each other and the scientific community at large about the results obtained from space life sciences studies. Integration tasks for the 1YM are based on current experience from the ISS and previous efforts on the Russian space station Mir. Closer coordination between international partners requires more common approaches to remove barriers to multilateral resource utilization on the ISS. Greater integration in implementation should increase utilization efficiency to benefit all participants in spaceflight human research. This presentation will describe the overarching principles for multilateral data collection, analysis and sharing and for data security for medical and research data shared between ISS partners prior to release in public forums
Cardiovascular Disease Outcomes Among the NASA Astronaut Corps
BACKGROUND: Acute effects of spaceflight on the cardiovascular system have been studied extensively, but the combined chronic effects of spaceflight and aging are not well understood. Preparation for and participation in spaceflight activities are associated with changes in the cardiovascular system such as decreased carotid artery distensibility and decreased ventricular mass which may lead to an increased risk of cardiovascular disease. Additionally, astronauts who travel into space multiple times or for longer durations may be at an increased risk across their lifespan. To that end, the purpose of this study was to determine the incidence of common cardiovascular disease (CVD) outcomes among the NASA astronaut corps during their active career and through retirement. METHODS: Cardiovascular disease outcomes were defined as reports of any of the following: myocardial infarction (MI), revascularization procedures (coronary artery bypass graft surgery [CABG] or percutaneous coronary intervention [PCI]), hypertension, stroke or transient ischemic attack [TIA], heart failure, or total CVD (as defined by the AHA - combined outcome of MI, Angina Pectoris, heart failure, stroke, and hypertension). Each outcome was identified individually from review of NASA's Electronic Medical Record (EMR), EKG reports, and death certificates using ICD-9 codes as well as string searches of physician notes of astronaut exams that occurred between 1959 and 2016. RESULTS: Of 338 NASA astronauts selected as of 2016, 9 reported an MI, 12 reported a revascularization procedure, (7 PCI and 5 CABG), 4 reported Angina (without MI), 5 reported heart failure, 9 reported stroke/TIA, and 96 reported hypertension. Total CVD was reported in 105 astronauts. No astronaut who had an MI or revascularization procedure flew a spaceflight mission following the event. All MI, revascularization, and stroke events occurred in male astronauts. When reviewing astronaut ECG reports, abnormal ECG reports were found in only 8% of records (n=430) and mainly among retired astronauts (82%), with marked sinus bradycardia being the reason for the abnormal classification
Construction and characterisation of infectious recombinant HIV-1 clones containing CTL epitopes from structural proteins in Nef.
In this study the construction is described of HIV-1 molecular clones in which CTL epitopes from RT or Env late proteins were inserted into the Nef early protein. The ectopic epitopes were efficiently processed from the recombinant Nef proteins, were recognized by their cognate CTL in cytolytic assays, and did not perturb virus replication or viral protein expression in vitro. These recombinant viruses will therefore be an important tool in studying the effect of distinct epitope expression kinetics on the efficiency of CTL-mediated suppression of HIV-1 replication
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