15 research outputs found
Healthcare Personnel And Nosocomial Transmission Of Pandemic 2009 Influenza
Knowledge regarding the modes of transmission of pandemic 2009 H1N1 influenza continues to develop, as do recommendations for the prevention of spread within healthcare facilities. The adoption of the most prudent, multifaceted approaches is recommended until there is significant evidence to reduce protective measures. The greatest threat to healthcare personnel and patients appears to be exposure to patients, healthcare personnel, or visitors who have not been recognized as contagious. The processes used within healthcare facilities must hold this concept central to any infection control plan and act in a preventive manner. This article focuses on the development of an algorithm for intensive care unit intake precautions, based on the early identification of potential source patients, as well as appropriate selection and adequate use of personal protective equipment. Visitor management, hand and respiratory hygiene, and cough etiquette have been used as measures to decrease the spread of infection. Vaccination of healthcare personnel, combined with work furlough for ill workers, is also explored. Recommendations include the elimination of potential exposures, engineering and administrative controls, and utilization of personal protective equipment. Copyright © 2010 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins
Induction of cortical endoplasmic reticulum by dimerization of a coatomer-binding peptide anchored to endoplasmic reticulum membranes
Cortical endoplasmic reticulum (cER) is a permanent feature of yeast cells but occurs transiently in most animal cell types. Ist2p is a transmembrane protein that permanently localizes to the cER in yeast. When Ist2 is expressed in mammalian cells, it induces abundant cER containing Ist2. Ist2 cytoplasmic C-terminal peptide is necessary and sufficient to induce cER. This peptide sequence resembles classic coat protein complex I (COPI) coatomer protein-binding KKXX signals, and indeed the dimerized peptide binds COPI in vitro. Controlled dimerization of this peptide induces cER in cells. RNA interference experiments confirm that coatomer is required for cER induction in vivo, as are microtubules and the microtubule plus-end binding protein EB1. We suggest that Ist2 dimerization triggers coatomer binding and clustering of this protein into domains that traffic at the microtubule growing plus-end to generate the cER beneath the plasma membrane. Sequences similar to the Ist2 lysine-rich tail are found in mammalian STIM proteins that reversibly induce the formation of cER under calcium control
Engagement and education: Care of the critically ill and injured during pandemics and disasters: CHEST consensus statement
Definitive Care for the Critically Ill During a Disaster: a Framework for Optimizing Critical Care Surge Capacity: From a Task Force for Mass Critical Care Summit Meeting, January 26-27, 2007, Chicago, IL
BACKGROUND:
Plausible disasters may yield hundreds or thousands of critically ill victims. However, most countries, including those with widely available critical care services, lack sufficient specialized staff, medical equipment, and ICU space to provide timely, usual critical care for a large influx of additional patients. Shifting critical care disaster preparedness efforts to augment limited, essential critical care (emergency mass critical care [EMCC]), rather than to marginally increase unrestricted, individual-focused critical care may provide many additional people with access to life-sustaining interventions. In 2007, in response to the increasing concern over a severe influenza pandemic, the Task Force on Mass Critical Care (hereafter called the Task Force) convened to suggest the essential critical care therapeutics and interventions for EMCC. TASK FORCE SUGGESTIONS: EMCC should include the following: (1) mechanical ventilation, (2) IV fluid resuscitation, (3) vasopressor administration, (4) medication administration for specific disease states (eg, antimicrobials and antidotes), (5) sedation and analgesia, and (6) select practices to reduce adverse consequences of critical illness and critical care delivery. Also, all hospitals with ICUs should prepare to deliver EMCC for a daily critical care census at three times their usual ICU capacity for up to 10 days. DISCUSSION:
By using the Task Force suggestions for EMCC, communities may better prepare to deliver augmented critical care in response to disasters. In light of current mass critical care data limitations, the Task Force suggestions were developed to guide preparedness but are not intended as strict policy mandates. Additional research is required to evaluate EMCC and revise the strategy as warranted
Resource-poor settings: infrastructure and capacity building: care of the critically ill and injured during pandemics and disasters: CHEST consensus statement
BACKGROUND: Planning for mass critical care (MCC) in resource-poor or constrained settings has been largely ignored, despite their large populations that are prone to suffer disproportionately from natural disasters. Addressing MCC in these settings has the potential to help vast numbers of people and also to inform planning for better-resourced areas.
METHODS: The Resource-Poor Settings panel developed five key question domains; defining the term resource poor and using the traditional phases of disaster (mitigation/preparedness/response/recovery), literature searches were conducted to identify evidence on which to answer the key questions in these areas. Given a lack of data upon which to develop evidence-based recommendations, expert-opinion suggestions were developed, and consensus was achieved using a modified Delphi process.
RESULTS: The five key questions were then separated as follows: definition, infrastructure and capacity building, resources, response, and reconstitution/recovery of host nation critical care capabilities and research. Addressing these questions led the panel to offer 33 suggestions. Because of the large number of suggestions, the results have been separated into two sections: part 1, Infrastructure/Capacity in this article, and part 2, Response/Recovery/Research in the accompanying article.
CONCLUSIONS: Lack of, or presence of, rudimentary ICU resources and limited capacity to enhance services further challenge resource-poor and constrained settings. Hence, capacity building entails preventative strategies and strengthening of primary health services. Assistance from other countries and organizations is needed to mount a surge response. Moreover, planning should include when to disengage and how the host nation can provide capacity beyond the mass casualty care event
Engagement and education: care of the critically ill and injured during pandemics and disasters: CHEST consensus statement
BACKGROUND: Engagement and education of ICU clinicians in disaster preparedness is fragmented by time constraints and institutional barriers and frequently occurs during a disaster. We reviewed the existing literature from 2007 to April 2013 and expert opinions about clinician engagement and education for critical care during a pandemic or disaster and offer suggestions for integrating ICU clinicians into planning and response. The suggestions in this article are important for all of those involved in a pandemic or large-scale disaster with multiple critically ill or injured patients, including front-line clinicians, hospital administrators, and public health or government officials.
METHODS: A systematic literature review was performed and suggestions formulated according to the American College of Chest Physicians (CHEST) Consensus Statement development methodology. We assessed articles, documents, reports, and gray literature reported since 2007. Following expert-informed sorting and review of the literature, key priority areas and questions were developed. No studies of sufficient quality were identified upon which to make evidence-based recommendations. Therefore, the panel developed expert opinion-based suggestions using a modified Delphi process.
RESULTS: Twenty-three suggestions were formulated based on literature-informed consensus opinion. These suggestions are grouped according to the following thematic elements: (1) situational awareness, (2) clinician roles and responsibilities, (3) education, and (4) community engagement. Together, these four elements are considered to form the basis for effective ICU clinician engagement for mass critical care.
CONCLUSIONS: The optimal engagement of the ICU clinical team in caring for large numbers of critically ill patients due to a pandemic or disaster will require a departure from the routine independent systems operating in hospitals. An effective response will require robust information systems; coordination among clinicians, hospitals, and governmental organizations; pre-event engagement of relevant stakeholders; and standardized core competencies for the education and training of critical care clinicians
Bedeutung und Anwendung
Title Page, Table of Contents, Motivation
iv
Concepts
v
Introduction
vii
1 Fundamentals
1
1.1 Meaning of isostasy and rigidity
1
1.1.1 Isostasy according to Pratt
1
1.1.2 Isostasy according to Airy
2
1.1.3 Isostasy according to Vening-Meinesz
2
1.1.4 Elastic thickness and flexural rigidity
4
1.2 Methods for estimation of flexural parameters
5
1.2.1 Spectral methods
5
1.2.2 Advantage and disadvantage of spectral methods
10
1.2.3 Convolution method
11
1.2.4 Advantage and disadvantage of the convolution method
12
1.2.5 Conclusion
12
1.3 Gravity inversion according to Parker algorithm
13
1.3.1 Introduction
13
1.3.2 Method
13
1.3.3 Synthetic example
14
1.4 Internal loads
16
1.4.1 Calculation of gravity effect of sediments with slice program
16
1.4.2 Pseudo topography
17
2 Theoretical basics and development of the analytical solution
19
2.1 Differential equation
19
2.1.1 Plate theory according to Kirchhoff
19
2.1.2 Beam on elastic foundation
20
2.1.3 Application in geological sciences
23
2.2 Formula according to Hertz
25
2.2.1 Investigation of the Logarithm function
27
2.2.2 Investigation of the Sine function
29
2.2.3 Summary of the behavior of the functions
30
2.3 New analytical solution
31
2.3.1 Introduction
31
2.3.2 Modification and substitution
31
2.3.3 Investigation of the graph
33
2.3.4 Unification of the analytical solution
35
2.4 Transfer function
38
2.4.1 Introduction
38
2.4.2 Transfer function
39
2.4.3 Verification of the analytical solution
41
2.4.4 Conclusion.
42
2.5 Comparison with FFT solution
43
2.5.1 Comparison with flexure curves
43
2.5.2 Investigation of dependence from grid parameters
44
2.5.3 Boundary cases for elastic thickness
47
2.5.4 Comparison with Vening-Meinesz solution
49
2.5.5 Conclusion
50
2.6 Software concept
51
2.6.1 Introduction
51
2.6.2 Flexure curves and CMI
52
2.6.3 Radius of convolution
52
2.6.4 Iterative estimation of elastic thickness
54
2.6.5 Elastic thickness distribution
56
2.6.6 Reference depth
57
2.7 Comparison with Finite Element modeling
59
2.7.1 Influence of input parameters
61
2.7.2 Conclusion
69
3\. Application of the analytical solution
70
3.1 Pacific Ocean
71
3.1.1 Input data
71
3.1.2 Preliminary investigations
72
3.1.3 Estimation of gravity CMI
73
3.1.4 Estimation of rigidity And elastic thickness
76
3.1.5 Discussion and conclusion.
77
3.2 Central Andes
80
3.2.1 Input data
80
3.2.2 Preliminary investigation
82
3.2.3 Estimation of rigidity and elastic thickness
83
3.2.4 Discussion and conclusion.
86
3.3 Southern Andes
91
3.3.1 Input data
91
3.3.2 Estimation of rigidity and elastic thickness
92
3.3.3 Discussion and conclusion.
93
4 Discussion of results
98
4.1 Thick plate theory
98
4.2 Influence of temperature
99
4.2.1 Introduction
99
4.2.2 Synthetic example
99
4.2.3 Application in geological sciences
101
4.3 Significance of input parameters
105
4.3.1 Deviation of height
106
4.3.2 Deviation of gravity
107
4.3.3 Deviation of Young's modulus
107
4.3.4 Deviation of Poisson ratio
108
4.3.5 Deviation of density of crust
109
4.3.6 Deviation of density of mantle
109
4.3.7 Deviation of elastic thickness
110
4.3.8 Conclusion
111
4.4 Variation of Young's modulus
112
4.5 Visco-elastic behavior
116
4.6 Final comments and future directions
122
5 Appendix
I
5.1 Density-porosity formula
I
5.2 Comparison of flexure curves
III
5.2.1. FFT solution compared with Logarithm and Sine function
III
5.2.2. Comparison of output from computer program with FFT
IV
5.3 FE models
V
5.3.1. Calculation input parameters and results
VI
5.3.2. Settings of the FE models
IX
Acknowledgement, References
X
Notation
XI
Abbreviations
XIV
Index of Tables
XV
Index of Figures
XVI
ReferencesIn 1939 a new concept was introduced by Vening-Meinesz proposing that the
flexural strength of the lithosphere must be considered for isostatic models.
A 4th order differential equation describing the flexure of a thin plate was
developed. In the past the equation has been solved in frequency space using
spectral methods (coherence and admittance). However, the admittance and
coherence techniques have been questioned when applied to continental
lithosphere. Both methods require an averaging process; therefore the
variation in rigidity may be retrieved only to a limited extent. A large
spatial window with a side length of at least 375 km is required over the
study area. And, in where the input topography is characterized by low
topographic variation, the method becomes unstable. These problems can be
overcome by calculating the flexural rigidity with the convolution approach
and furthermore with the use of a newly derived analytical solution of the
differential equation mentioned above. This solution was developed out of
three solutions from Hertz and has been made applicable to geological science.
The analytical solution has been applied to both oceanic lithosphere (Nazca
plate) and continental lithosphere (Central and Patagonian Andes). The
resulting flexural rigidity values and their variations have been compared
with the ideas and concepts developed by the members of the SFB267 community,
and correlate well with tectonic units and fault systems. In the past the
elastic thickness has been used synonymously for the flexural rigidity.
However, the analytical solution leads to a new interpretation and meaning of
the elastic thickness. It is shown that it is sufficient to operate with a
constant value for both gravity and Poisson's ratio, as the variation of
either parameter does not lead to a significant change in the distribution of
flexural rigidity. Young's modulus is shown to be the driving factor for the
flexural deformation. A temperature moment must also be taken into account in
flexural investigations. Thus, the variation of the elastic thickness can be
explained by temperature distribution and a change of the Young's modulus. A
new definition of elastic thickness can be obtained: the value of the
calculated elastic thickness is equivalent to the value of thickness of a
corresponding plate described by a constant Young's modulus. Computations
using the differential equation are valid for the crust/mantle interface
(Moho) as well as the lithosphere/ asthenosphere boundary. The calculated
boundary surface can be shifted at the position of the boundary at which a
significant change of Young's modulus takes place.Im Jahre 1939 wurde von Vening-Meinesz eine Theorie entwickelt, welche die
Rigidität der Lithosphärenplatte innerhalb isostatischer Betrachtungen
berücksichtigte. Dazu wurde eine Differentialgleichung 4. Ordnung verwendet,
welche die Deformation einer dünnen Platte beschreibt. In der Vergangenheit
wurde die Gleichung mittels der Spektralmethoden im Frequenz-Bereich gelöst.
Aber bezüglich der Anwendung der Kohärenz- und Admittanzmethode auf die
Kontinente wurde ihre Nützlichkeit aufgrund der Nachteile, welche durch den
Spektralansatz entstehen, in Frage gestellt. Dieser Ansatz bedingt eine
Durchschnittsbildung, welche im Falle einer sich räumlich stark variierenden
Rigidität dazu führen kann, dass jene Variation nur bis zu einem begrenzten
Mabe aufgelöst wird. Für das Untersuchungsgebiet ist eine Seitenlänge von
mindestens erforderlich. Ein weiteres Problem tritt im Falle niedriger
Topographie auf, da kleinere Spektralwerte zu Instabilitaeten innerhalb der
Anwendung führen können. Durch die Verwendung der Konvolutionsmethode und der
neu entwickelten analytischen Lösung der obig eingeführten
Differentialgleichung werden diese Nachteile überwunden. Diese analytische
Lösung wurde aus drei verschiedenen Lösungen nach Hertz entwickelt und für die
geologischen Wissenschaften anwendbar gemacht. Die analytische Lösung wurde
auf die ozeanische Lithosphäre im Bereich des Pazifik (Nazca-Platte) und auf
die kontinentale Lithosphäre im Bereich der Zentral - und der Patagonischen
Anden angewendet. Die resultierende Rigiditätsverteilung wird mit den von den
Mitgliedern der SFB267 Gemeinschaft entwickelten Ideen und Konzepten
verglichen, und ist durch eine gute Korrelation mit den tektonischen Einheiten
und Störungssystemen charakterisiert. Bisher wurde die elastische Dicke und
die flexurelle Rigidität synonym verwendet. Aber die analytische Lösung führte
zu einem neuen Verständnis und Interpretation der elastischen Dicke. In
Anbetracht der Untersuchungen zur Signifikanz der Inputparameter ist es
zulässig mit einem konstanten Wert für die Schwere und dem Poisson-Verhältnis
zu arbeiten, denn dies wird nicht zu signifikanten Unterschieden im Ergebnis
führen. Dies gilt nicht für das Elastizitätsmodul, denn dieser Parameter ist
ein entscheidender Faktor für das Deformationsverhalten. Daher kann die
elastische Dicke auch als äquivalente Plattendicke für eine Platte konstanten
Elastizitätsmoduls definiert werden. Zudem wurde herausgefunden, daß das
Temperaturmoment in den weiteren Untersuchungen mit berücksichtigt werden
muss. Damit kann die beobachtete Variation der elastischen Dicke durch die
Temperaturverteilung und die Veränderung des Elastizitätsmoduls erklärt
werden. Zusätzlich wurde gezeigt, daß die Berechnungen mittels der
Differentialgleichung und der analytischen Lösung sowohl für die
Krusten/Mantel Grenze als auch die Lithosphären/Asthenosphären Grenze gültig
sind. Dabei ist entscheidend, an welcher Grenzfläche sich das
Elastizitätsmodul ändert