1,255 research outputs found

    Conservation laws for potential vorticity in a salty ocean or cloudy atmosphere

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    One of the most important conservation laws in atmospheric and oceanic science is conservation of potential vorticity. The original derivation is approximately a century old, in the work of Rossby and Ertel, and it is related to the celebrated circulation theorems of Kelvin and Bjerknes. However, the laws apply to idealized fluids, and extensions to more realistic scenarios have been problematic. Here, these laws are extended to hold with additional fundamental complexities, including salinity in the ocean, or moisture and clouds in the atmosphere. In the absence of these additional complexities, it is known that potential vorticity is conserved following each fluid parcel; here, for a salty ocean or cloudy atmosphere, the general conserved quantity is potential vorticity integrated over certain pancake-shaped volumes. Furthermore, the conservation laws are also related to a symmetry in the Lagrangian, which brings a connection to the symmetry-conservation relationships seen in other areas of physics.Comment: 11 pages, 3 figure

    Sternal non-union in a professional hockey player: considerations for return to play

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    We describe a healthy 40-year old professional hockey player with an asymptomatic sternal non-union following aortic root surgery. The purpose of this case report is to make orthopedic surgeons aware of the possibility of this complication following sternotomy, and to discuss the considerations involved in return to play in contact sports. We will discuss our work-up, evaluation, and management of a sternal non-union in a professional athlete. Patient's consent has been obtained

    The expression and prognostic significance of bcl-2-associated transcription factor 1 in rectal cancer following neoadjuvant therapy

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    Acknowledgements This study was supported by funding from the Encompass kick start and SMART:Scotland award schemes of Scottish Enterprise and Friends of Anchor. The Grampian Biorepository assisted with the immunohistochemical investigations.Peer reviewedPostprin

    Identification of a Novel Invasion-Promoting Region in Insulin Receptor Substrate 2

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    Although the insulin receptor substrate (IRS) proteins IRS1 and IRS2 share considerable homology and activate common signaling pathways, their contributions to breast cancer are distinct. IRS1 has been implicated in the proliferation and survival of breast tumor cells. In contrast, IRS2 facilitates glycolysis, invasion, and metastasis. To determine the mechanistic basis for IRS2-dependent functions, we investigated unique structural features of IRS2 that are required for invasion. Our studies revealed that the ability of IRS2 to promote invasion is dependent upon upstream insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor (IR) activation and the recruitment and activation of phosphatidylinositol 3-kinase (PI3K), functions shared with IRS1. In addition, a 174-amino-acid region in the IRS2 C-terminal tail, which is not conserved in IRS1, is also required for IRS2-mediated invasion. Importantly, this invasion (INV) region is sufficient to confer invasion-promoting ability when swapped into IRS1. However, the INV region is not required for the IRS2-dependent regulation of glucose uptake. Bone morphogenetic protein 2-inducible kinase (BMP2K) binds to the INV region and contributes to IRS2-dependent invasion. Taken together, our data advance the mechanistic understanding of how IRS2 regulates invasion and reveal that IRS2 functions important for cancer can be independently targeted without interfering with the metabolic activities of this adaptor protein

    Let Them In: Family Presence During Intensive Care Unit Procedures

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    Families have for decades advocated for full access to intensive care units (ICUs) and meaningful partnership with clinicians, resulting in gradual improvements in family access and collaboration with ICU clinicians. Despite such advances, family members in adult ICUs are still commonly asked to leave the patient’s room during invasive bedside procedures, regardless of whether the patient would prefer family to be present. Physicians may be resistant to having family members at the bedside due to concerns about trainee education, medicolegal implications, possible effects on the technical quality of procedures due to distractions, and procedural sterility. Limited evidence from parallel settings does not support these concerns. Family presence during ICU procedures, when the patient and family member both desire it, fulfills the mandates of patient-centered care. We anticipate that such inclusion will increase family engagement, improve patient and family satisfaction, and may, on the basis of studies of open visitation, pediatric ICU experience, and family presence during cardiopulmonary resuscitation, decrease psychological distress in patients and family members. We believe these goals can be achieved without compromising the quality of patient care, increasing provider burden significantly, or increasing risks of litigation. In this article, we weigh current evidence, consider historical objections to family presence at ICU procedures, and report our clinical experience with the practice. An outline for implementing family procedural presence in the ICU is also presented

    CamDec: Advancing axis P1435-LE video camera security using honeypot-based deception

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    The explosion of online video streaming in recent years resulted in advanced services both in terms of efficiency and convenience. However, Internet-connected video cameras are prone to exploitation, leading to information security issues and data privacy concerns. The proliferation of video-capable Internet of Things devices and cloud-managed surveillance systems further extend these security issues and concerns. In this paper, a novel approach is proposed for video camera deception via honeypots, offering increased security measures compared to what is available on conventional Internet-enabled video cameras

    Concurrent Imaging of Synaptic Vesicle Recycling and Calcium Dynamics

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    Synaptic transmission involves the calcium dependent release of neurotransmitter from synaptic vesicles. Genetically encoded optical probes emitting different wavelengths of fluorescent light in response to neuronal activity offer a powerful approach to understand the spatial and temporal relationship of calcium dynamics to the release of neurotransmitter in defined neuronal populations. To simultaneously image synaptic vesicle recycling and changes in cytosolic calcium, we developed a red-shifted reporter of vesicle recycling based on a vesicular glutamate transporter, VGLUT1-mOrange2 (VGLUT1-mOr2), and a presynaptically localized green calcium indicator, synaptophysin-GCaMP3 (SyGCaMP3) with a large dynamic range. The fluorescence of VGLUT1-mOr2 is quenched by the low pH of synaptic vesicles. Exocytosis upon electrical stimulation exposes the luminal mOr2 to the neutral extracellular pH and relieves fluorescence quenching. Reacidification of the vesicle upon endocytosis again reduces fluorescence intensity. Changes in fluorescence intensity thus monitor synaptic vesicle exo- and endocytosis, as demonstrated previously for the green VGLUT1-pHluorin. To monitor changes in calcium, we fused the synaptic vesicle protein synaptophysin to the recently improved calcium indicator GCaMP3. SyGCaMP3 is targeted to presynaptic varicosities, and exhibits changes in fluorescence in response to electrical stimulation consistent with changes in calcium concentration. Using real time imaging of both reporters expressed in the same synapses, we determine the time course of changes in VGLUT1 recycling in relation to changes in presynaptic calcium concentration. Inhibition of P/Q- and N-type calcium channels reduces calcium levels, as well as the rate of synaptic vesicle exocytosis and the fraction of vesicles released
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