2,903 research outputs found

    Why didn't Darwin discover Mendel's laws?

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    Darwin's focus on small quantitative variations as the raw material of evolution may have prevented him from discovering the laws of inheritance

    Combined SIRT3 and SIRT5 deletion is associated with inner retinal dysfunction in a mouse model of type 1 diabetes

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    Abstract Diabetic retinopathy (DR) is a major cause of blindness in working adults in the industrialized world. In addition to vision loss caused by macular edema and pathological angiogenesis, DR patients often exhibit neuronal dysfunction on electrophysiological testing, suggesting that there may be an independent neuronal phase of disease that precedes vascular disease. Given the tremendous metabolic requirements of the retina and photoreceptors in particular, we hypothesized that derangements in metabolic regulation may accelerate retinal dysfunction in diabetes. As such, we induced hyperglycemia with streptozotocin in mice with monoallelic Nampt deletion from rod photoreceptors, mice lacking SIRT3, and mice lacking SIRT5 and tested multiple components of retinal function with electroretinography. None of these mice exhibited accelerated retinal dysfunction after induction of hyperglycemia, consistent with normal-appearing retinal morphology in hyperglycemic Sirt3 −/− or Sirt5 −/− mice. However, mice lacking both SIRT3 and SIRT5 (Sirt3 −/− Sirt5 −/− mice) exhibited significant evidence of inner retinal dysfunction after induction of hyperglycemia compared to hyperglycemic littermate controls, although this dysfunction was not accompanied by gross morphological changes in the retina. These results suggest that SIRT3 and SIRT5 may be involved in regulating neuronal dysfunction in DR and provide a foundation for future studies investigating sirtuin-based therapies

    Aerotoxic Syndrome: A New Occupational Disease?

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    Background: Concerns related to adverse health effects experienced by aircrew exposed to aircraft contaminated air have been ongoing for over 6 decades. Unfiltered breathing air is supplied to the cabin via the engine compressor. The likelihood that oil leaking over the engine oil seals may enter the cabin air supply has prompted continuing debate about the hazards associated with exposure to neurotoxic substances and to the thermally degraded or pyrolysed mixture. In this study, we undertook an in-depth investigation of aircrew involved in suspected aircraft contaminated air events.  Methods: Two studies were conducted to review the circumstances and symptoms of a cohort of aircrew working in the pressurized air environment of aircraft. A table of effects was then used for categorizing symptoms and reviewing other sources of data related to aircraft fluids and selected other conditions.  Results: Both acute and chronic exposures to neurotoxic and a wide range of thermally degraded substances were confirmed, along with a clear pattern of acute and chronic adverse effects. The latter were supported by medical findings and diagnoses, notably involving the neurological, neurobehavioural and respiratory systems.  Conclusion: A clear cause and effect relationship has been identified linking the symptoms, diagnoses and findings to the occupational environment. Recognition of this new occupational disorder and a clear medical investigation protocol are urgently needed

    Managing at the Speed of Light: Improving Mission-Support Performance

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    The House and Senate Energy and Water Development Appropriations Subcommittees requested this study to help DOE's three major mission-support organizations improve their operations to better meet the current and future needs of the department. The passage of the Recovery Act only increased the importance of having DOE's mission-support offices working in the most effective, efficient, and timely manner as possible. While following rules and regulations is essential, the foremost task of the mission-support offices is to support the department's mission, i.e., the programs that DOE is implementing, whether in Washington D.C. or in the field. As a result, the Panel offered specific recommendations to strengthen the mission-focus and improve the management of each of the following support functions based on five "management mandates":- Strategic Vision- Leadership- Mission and Customer Service Orientation- Tactical Implementation- Agility/AdaptabilityKey FindingsThe Panel made several recommendations in each of the functional areas examined and some overarching recommendations for the corporate management of the mission-support offices that they believed would result in significant improvements to DOE's mission-support operations. The Panel believed that adopting these recommendations will not only make DOE a better functioning organization, but that most of them are essential if DOE is to put its very large allocation of Recovery Act funding to its intended uses as quickly as possible
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