4,990 research outputs found
Organisational response to the 2007 Ruapehu Crater Lake breakout lahar in New Zealand: Use of communication in creating an effective response
When Mt. Ruapehu erupted in 1995-1996 in New Zealand, a tephra barrier was created alongside Crater Lake on the top of Mt. Ruapehu. This barrier acted as a dam, with Crater Lake rising behind it over time. In 2007 the lake breached the dam and a lahar occurred down the Whangaehu Valley and across the volcano’s broad alluvial ring-plain. Given the lahar history from Ruapehu, the risk from the 2007 event was identified beforehand and steps taken to reduce the risks to life and infrastructure. An early warning system was set up to notify when the dam had broken and the lahar had occurred. Physical works to mitigate the risk were put in place. A planning group was also formed and emergency management plans were put in place to respond to the risk. To assess the effectiveness of planning for and responding to the lahar, semi-structured interviews were undertaken with personnel from key organisations both before and after the lahar event. This chapter discusses the findings from the interviews in the context of communications, and highlights how good communications contributed to an effective emergency management response. As the potential for a lahar was identifiable, approximately 10 years of lead-up time was available to install warning system hardware, implement physical mitigation measures, create emergency management plans, and practice exercises for the lahar. The planning and exercising developed effective internal communications, engendered relationships, and moved individuals towards a shared mental model of how a respond to the event. Consequently, the response played out largely as planned with only minor communication issues occurring on the day of the lahar. The minor communication issues were due to strong personal connections leading to at least one case of the plan being bypassed. Communication levels during the lahar event itself were also different from that experienced in exercises, and in some instances communications were seen to increase almost three-fold. This increase in level of communication, led to some difficulty in getting through to the main Incident Control Point. A final thought regarding public communications prior to the event was that more effort could have been given to developing and integrating public information about the lahar, to allow for ease of understanding about the event and integration of information across agencies.falseSubmitte
How do I perform whole blood exchange?
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154397/1/trf15660_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154397/2/trf15660.pd
Spectroscopy of free radicals and radical containing entrance-channel complexes in superfluid helium nano-droplets
The spectroscopy of free radicals and radical containing entrance-channel
complexes embedded in superfluid helium nano-droplets is reviewed. The
collection of dopants inside individual droplets in the beam represents a
micro-canonical ensemble, and as such each droplet may be considered an
isolated cryo-reactor. The unique properties of the droplets, namely their low
temperature (0.4 K) and fast cooling rates ( K s) provides
novel opportunities for the formation and high-resolution studies of molecular
complexes containing one or more free radicals. The production methods of
radicals are discussed in light of their applicability for embedding the
radicals in helium droplets. The spectroscopic studies performed to date on
molecular radicals and on entrance / exit-channel complexes of radicals with
stable molecules are detailed. The observed complexes provide new information
on the potential energy surfaces of several fundamental chemical reactions and
on the intermolecular interactions present in open-shell systems. Prospects of
further experiments of radicals embedded in helium droplets are discussed,
especially the possibilities to prepare and study high-energy structures and
their controlled manipulation, as well as the possibility of fundamental
physics experiments.Comment: 25 pages, 12 figures, 4 tables (RevTeX
A functional polymorphism in the 5HTR2C gene associated with stress responses also predicts incident cardiovascular events.
Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (rs6318) of the 5HTR2C gene located on the X-chromosome is associated with hypothalamic-pituitary-adrenal axis response to a stress recall task, and with endophenotypes associated with cardiovascular disease (CVD). These findings suggest that individuals carrying the rs6318 Ser23 C allele will be at higher risk for CVD compared to Cys23 G allele carriers. The present study examined allelic variation in rs6318 as a predictor of coronary artery disease (CAD) severity and a composite endpoint of all-cause mortality or myocardial infarction (MI) among Caucasian participants consecutively recruited through the cardiac catheterization laboratory at Duke University Hospital (Durham, NC) as part of the CATHGEN biorepository. Study population consisted of 6,126 Caucasian participants (4,036 [65.9%] males and 2,090 [34.1%] females). A total of 1,769 events occurred (1,544 deaths and 225 MIs; median follow-up time = 5.3 years, interquartile range = 3.3-8.2). Unadjusted Cox time-to-event regression models showed, compared to Cys23 G carriers, males hemizygous for Ser23 C and females homozygous for Ser23C were at increased risk for the composite endpoint of all-cause death or MI: Hazard Ratio (HR) = 1.47, 95% confidence interval (CI) = 1.17, 1.84, p = .0008. Adjusting for age, rs6318 genotype was not related to body mass index, diabetes, hypertension, dyslipidemia, smoking history, number of diseased coronary arteries, or left ventricular ejection fraction in either males or females. After adjustment for these covariates the estimate for the two Ser23 C groups was modestly attenuated, but remained statistically significant: HR = 1.38, 95% CI = 1.10, 1.73, p = .005. These findings suggest that this functional polymorphism of the 5HTR2C gene is associated with increased risk for CVD mortality and morbidity, but this association is apparently not explained by the association of rs6318 with traditional risk factors or conventional markers of atherosclerotic disease
Ultrafast changes in lattice symmetry probed by coherent phonons
The electronic and structural properties of a material are strongly
determined by its symmetry. Changing the symmetry via a photoinduced phase
transition offers new ways to manipulate material properties on ultrafast
timescales. However, in order to identify when and how fast these phase
transitions occur, methods that can probe the symmetry change in the time
domain are required. We show that a time-dependent change in the coherent
phonon spectrum can probe a change in symmetry of the lattice potential, thus
providing an all-optical probe of structural transitions. We examine the
photoinduced structural phase transition in VO2 and show that, above the phase
transition threshold, photoexcitation completely changes the lattice potential
on an ultrafast timescale. The loss of the equilibrium-phase phonon modes
occurs promptly, indicating a non-thermal pathway for the photoinduced phase
transition, where a strong perturbation to the lattice potential changes its
symmetry before ionic rearrangement has occurred.Comment: 14 pages 4 figure
Atomic excitation during recollision-free ultrafast multi-electron tunnel ionization
Modern intense ultrafast pulsed lasers generate an electric field of
sufficient strength to permit tunnel ionization of the valence electrons in
atoms. This process is usually treated as a rapid succession of isolated
events, in which the states of the remaining electrons are neglected. Such
electronic interactions are predicted to be weak, the exception being
recollision excitation and ionization caused by linearly-polarized radiation.
In contrast, it has recently been suggested that intense field ionization may
be accompanied by a two-stage `shake-up' reaction. Here we report a unique
combination of experimental techniques that enables us to accurately measure
the tunnel ionization probability for argon exposed to 50 femtosecond laser
pulses. Most significantly for the current study, this measurement is
independent of the optical focal geometry, equivalent to a homogenous electric
field. Furthermore, circularly-polarized radiation negates recollision. The
present measurements indicate that tunnel ionization results in simultaneous
excitation of one or more remaining electrons through shake-up. From an atomic
physics standpoint, it may be possible to induce ionization from specific
states, and will influence the development of coherent attosecond XUV radiation
sources. Such pulses have vital scientific and economic potential in areas such
as high-resolution imaging of in-vivo cells and nanoscale XUV lithography.Comment: 17 pages, 4 figures, original format as accepted by Nature Physic
The Obligation of Physicians to Medical Outliers: A Kantian and Hegelian Synthesis
Background
Patients who present to medical practices without health insurance or with serious co-morbidities can become fiscal disasters to those who care for them. Their consumption of scarce resources has caused consternation among providers and institutions, especially as it concerns the amount and type of care they should receive. In fact, some providers may try to avoid caring for them altogether, or at least try to limit their institutional or practice exposure to them. Discussion
We present a philosophical discourse, with emphasis on the writings of Immanuel Kant and G.F.W. Hegel, as to why physicians have the moral imperative to give such outliers considerate and thoughtful care. Outliers are defined and the ideals of morality, responsibility, good will, duty, and principle are applied to the care of patients whose financial means are meager and to those whose care is physiologically futile. Actions of moral worth, unconditional good will, and doing what is right are examined. Summary
Outliers are a legitimate economic concern to individual practitioners and institutions, however this should not lead to an evasion of care. These patients should be identified early in their course of care, but such identification should be preceded by a well-planned recognition of this burden and appropriate staffing and funding should be secured. A thoughtful team approach by medical practices and their institutions, involving both clinicians and non-clinicians, should be pursued
Interferon regulatory factor 8-deficiency determines massive neutrophil recruitment but T cell defect in fast growing granulomas during tuberculosis
Following Mycobacterium tuberculosis (Mtb) infection, immune cell recruitment in lungs is pivotal in establishing protective immunity through granuloma formation and neogenesis of lymphoid structures (LS). Interferon regulatory factor-8 (IRF-8) plays an important role in host defense against Mtb, although the mechanisms driving anti-mycobacterial immunity remain unclear. In this study, IRF-8 deficient mice (IRF-8−/−) were aerogenously infected with a low-dose Mtb Erdman virulent strain and the course of infection was compared with that induced in wild-type (WT-B6) counterparts. Tuberculosis (TB) progression was examined in both groups using pathological, microbiological and immunological parameters. Following Mtb exposure, the bacterial load in lungs and spleens progressed comparably in the two groups for two weeks, after which IRF-8−/− mice developed a fatal acute TB whereas in WT-B6 the disease reached a chronic stage. In lungs of IRF-8−/−, uncontrolled growth of pulmonary granulomas and impaired development of LS were observed, associated with unbalanced homeostatic chemokines, progressive loss of infiltrating T lymphocytes and massive prevalence of neutrophils at late infection stages. Our data define IRF-8 as an essential factor for the maintenance of proper immune cell recruitment in granulomas and LS required to restrain Mtb infection. Moreover, IRF-8−/− mice, relying on a common human and mouse genetic mutation linked to susceptibility/severity of mycobacterial diseases, represent a valuable model of acute TB for comparative studies with chronically-infected congenic WT-B6 for dissecting protective and pathological immune reactions
The role of tyrosine M210 in the initial charge separation in the reaction center of Rhodobacter sphaeroides
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