scholarly journals Definition of catheter jamming: A mechanical analysis of catheter fracture tension and fracture strain

2021 ◽  
pp. 1-7
Author(s):  
Feng-Xian Li ◽  
Peng Su ◽  
Yan-Ping Li ◽  
Mei-Jing Tian ◽  
Hong-Yang Zhang ◽  
...  
Keyword(s):  
Fracture Strain ◽  
Tensile Force ◽  
Mechanical Analysis ◽  
Short Term ◽  
Single Lumen ◽  
Catheter Failure ◽  
Indwelling Time ◽  
Definition Of ◽  
Catheter Fracture

BACKGROUND: Catheter jamming is an emerging and possibly underrated complication. OBJECTIVE: To find the criteria for determining if the catheter cannot be removed through the mechanical analysis of fracture tension and fracture strain (εf) of Peripheral Inserted Central Catheters (PICC). METHOD: We removed 30 pieces of PICC catheters from patients and recorded the indwelling time. Those with an indwelling time shorter than 12 weeks belonged to the short-term group. Those with an indwelling time longer than 12 weeks belonged to the long-term group. The first half of the same catheter is section A, and the second half is section B. The fraction tension and fracture strain of the catheter were measured, and statistical analysis was conducted. RESULTS: The fracture tension of catheter in sections A and B were 5.8917 ± 1.0095 and 6.0670 ± 0.8066 Newtons respectively (p= 0.393) and the fracture strain of catheter in sections A and B were 6.0611 ± 1.0810 and 6.2543 ± 0.7187 Newtons respectively (p= 0.343). The fracture tension of catheter in short-term and long-term group were 6.0696 ± 0.9414 and 5.9192 ± 0.8972 Newtons respectively (p= 0.535) and the fracture strain of catheter in short-term and long-term group were 6.0067 ± 0.7227 and 6.2584 ± 1.0212 respectively (p= 0.301). CONCLUSION: It is objective and consistent to take the catheter fracture tension as the standard. This standard would be able to accurately define the concept of catheter failure and reduce the risk of catheter fracture and the misdiagnosis of catheter failure. The catheter fracture tension and fracture strain was not affected by the catheter indwelling time. It is recommended to set the tensile force as 5 Newtons and carry it out at a speed of 100 mm/min for the catheter drawing of the PICC single-lumen silicone catheter (4.0F) from Budd Company.

scholarly journals When is a Learning Object not an Object: A first step towards a theory of learning objects

2002 ◽  
Vol 3 (2) ◽  
Author(s):  
Mike Sosteric ◽  
Susan Hesemeier
Keyword(s):  
Economies Of Scale ◽  
Learning Objects ◽  
Short Term ◽  
Object A ◽  
Smart Learning ◽  
Smart Learning Environments ◽  
Adequate Definition ◽  
Definition Of ◽  
Conceptual Confusion

<p> For some, “learning objects" are the “next big thing” in distance education promising smart learning environments, fantastic economies of scale, and the power to tap into expanding educational markets. While learning objects may be revolutionary in the long term, in the short term, definitional problems and conceptual confusion undermine our ability to understand and critically evaluate the emerging field. This article is an attempt to provide an adequate definition of learning objects by (a) jettisoning useless theoretical links hitherto invoked to theorize learning objects, and (b) reducing the definition of learning objects to the bare essentials. The article closes with suggestions for further research and further refinement of the definition of learning objects. </P>

scholarly journals Systema Temporis: A Time-Based Dimensional Framework for Consciousness and Cognition

2019 ◽  
Author(s):  
Lachlan Kent ◽  
George Van Doorn ◽  
Britt Klein
Keyword(s):  
Time Perception ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Dimensional Approach ◽  
Short Term ◽  
Hierarchical Framework ◽  
Time Consciousness ◽  
Emotion And Memory ◽  
Definition Of

This study uses a combined categorical-dimensional approach to depict a hierarchical framework for consciousness similar to, and contiguous with, factorial models of cognition (cf., intelligence). On the basis of the longstanding definition of time consciousness, the analysis employs a dimension of temporal extension, in the same manner that psychology has temporally organised memory (i.e., short-term, long-term, and long-lasting memories). By defining temporal extension in terms of the structure of time perception at short timescales (&lt; 100 s), memory and time consciousness are proposed to fit along the same logarithmic dimension. This suggests that different forms of time consciousness (e.g., experience, wakefulness, and self-consciousness) are embedded within, or supported by, the ascending timescales of different modes of memory (i.e., short-term, long-term, etc.). A secondary dimension is also proposed to integrate higher-order forms of consciousness/emotion and memory/cognition. The resulting two-dimensional structure accords with existing theories of cognitive and emotional intelligence.

Drinking problems among recidivist prisoners

1971 ◽  
Vol 1 (5) ◽  
pp. 388-399 ◽  
Author(s):  
Griffith Edwards ◽  
Celia Hensman ◽  
Julian Peto
Keyword(s):  
Operant Conditioning ◽  
Prison Population ◽  
Short Term ◽  
Social Instability ◽  
Drinking Problems ◽  
Homeless Men ◽  
Conditioning Model ◽  
Methodological Problems ◽  
Definition Of

SYNOPSISThe general relationship between alcohol and crime is reviewed, and five central methodological problems are identified relevant to prison population ‘alcoholism prevalence surveys’ as a prelude to a report of an investigation of 500 recidivist prisoners. The prevalence rate is shown to be highly dependent on the particular definition of ‘alcoholism’ which is employed. Long-term and short-term prisoner subgroups are compared, and similarities with a population of non-prisoner homeless men discussed. A ‘dependence score’ derived from an operant conditioning model of alcoholism correlates significantly with various measures of social instability.

Viscoelastic Properties of Semi-Crystalline Thermoplastic Polymers: Dynamic Analysis and Creep

2012 ◽  
Vol 188 ◽  
pp. 211-218 ◽  
Author(s):  
Dan Andrei Serban ◽  
Henry Hanson ◽  
Liviu Marşavina ◽  
Vadim V. Silberschmidt
Keyword(s):  
Viscoelastic Properties ◽  
Polymeric Materials ◽  
Mechanical Analysis ◽  
External Loading ◽  
Thermoplastic Polymer ◽  
Elastic Solids ◽  
Short Term ◽  
Creep Tests ◽  
And Storage

When subjected to external loading, polymeric materials behave in a manner intermediate between elastic solids and viscous fluids. Their mechanical properties depend on a material’s viscous flow, which, in turn, is influenced by (i) temperature, with its different magnitudes determining a ductile or brittle behaviour and (ii) time, through the effect of a deformation rate and long-term relaxation. Short-term viscoelastic properties (loss and storage moduli) of a studied semi-crystalline thermoplastic polymer were obtained using Dynamic Mechanical Analysis, while its long-term viscoelastic properties (compliances) were determined using creep tests.

scholarly journals EARTHQUAKE FORECAST BY TIME-DEPENDENT HAZARD MODELS

2017 ◽  
Vol 50 (3) ◽  
pp. 1309
Author(s):  
R. Console
Keyword(s):  
Epidemic Model ◽  
Stress Change ◽  
Time Dependent ◽  
Occurrence Rate ◽  
Hazard Models ◽  
Short Term ◽  
Probability Of Occurrence ◽  
Seismogenic Structures ◽  
Definition Of

This presentation outlines methodological aspects of earthquake forecasting. The recurring debates concerning predictability of earthquakes clearly show how this problem is centred on the difficulty of systematically testing the numerous methodologies that in the years have been proposed and sustained by the supporters of prediction. This difficulty starts, sometimes, from the lack of a quantitative and rigorous definition of the concerned precursor, and other times from the lack of continuous observations, upon which statistical analyses could be based. After an introduction concerning the definition of earthquake precursors, the way how to validate forecast hypotheses and the cost associated to their operational application, I give two examples of time-dependent hazard models, for long-term and short-term earthquake forecasts respectively. Considering the long-term forecast modelling, the effect of stress change due to previous historical earthquakes on the probability of occurrence of future earthquakes on neighbouring faults is taken into account. Following a standard methodology developed a couple of decades ago, the probability of occurrence in the next 50 years for a characteristic earthquake on known seismogenic structures can be estimated by a time-dependent renewal model. Then, a physical model for the Coulomb stress change caused by previous earthquakes on these structures is applied. The influence of this stress change on the occurrence rate of characteristic earthquakes is computed taking into account the permanent perturbation (clock advance). The method so developed is applied to the computation of earthquake hazard of the main seismogenic structures recognized in the Southern Apennines region, for which both historical and paleoseismological data are available. A popular short-term time dependent hazard forecast model is the epidemic model. In this model earthquakes are regarded as the realization of a stochastic point process, and their magnitude distribution is described by the Gutenberg-Richter law with a constant b-value. The occurrence rate density is computed by the sum of two terms, one representing the independent, or spontaneous activity, and the other representing the activity induced by previous earthquakes. While the first term depends only on space, the second one is factored into three terms that respectively include the magnitude, time and location of the past earthquakes. An example of application of the epidemic model to the 2009 L’Aquila seismic series is shown.

scholarly journals Zaniedbane emocjonalnie dzieci – symptomy, diagnoza, formy wsparcia w środowisku przedszkolnym

2020 ◽  
Vol 25 (3) ◽  
pp. 33-44
Author(s):  
Angelika Kleszczewska-Albińska
Keyword(s):  
Diagnostic Procedures ◽  
Kindergarten Teachers ◽  
Emotional Neglect ◽  
Short Term ◽  
Behavioral Techniques ◽  
Long Term Consequences ◽  
Neglected Children ◽  
Definition Of

Children Emotional Neglect – Symptoms, Diagnosis, Forms of Support in Kindergarten Environment This article aims to present analysis of possible actions of kindergarten teachers and other specialists working with emotionally neglected children. The first part of the text includes definition of emotional neglect and information about the symptoms observed in emotionally neglected child. The short term and long term consequences of emotional neglect in group of children aged 3–6 were shortly described. The characteristics enabling recognition of emotional neglect and diagnostic procedures facilitating identification of a problem by teachers and kindergarten specialists were given. Basic cues concerning the work with emotionally neglected child that can be accomplished in kindergarten, including description of basic behavioral techniques, were presented. The cues for working with neglecting parent were also given. The article serves as a preliminary set of indicators for working with emotionally neglected children.

Aneurysms in Vascular Access: State of the Art and Future Developments

2017 ◽  
Vol 18 (6) ◽  
pp. 464-472 ◽  
Author(s):  
Nicholas Inston ◽  
Hiren Mistry ◽  
James Gilbert ◽  
David Kingsmore ◽  
Zahid Raza ◽  
...  
Keyword(s):  
Vascular Access ◽  
Audience Participation ◽  
Short Term ◽  
Cross Sectional ◽  
Av Fistula ◽  
Active Audience ◽  
Cross Sectional Imaging ◽  
History Of ◽  
Definition Of

A master class was held at the Vascular Access at Charing Cross (VA@CX2017) conference in April 2017 with invited experts and active audience participation to discuss arteriovenous (AV) vascular access aneurysms, a serious and common complication of vascular access (VA). The natural history of aneurysms in VA is poorly defined, and although classifications exist they are not uniformly applied in studies or clinical practice. True and pseudo aneurysms of AV access occur. Whilst an AV fistula by definition is an abnormal dilatation of a blood vessel, an agreed definition of 18 mm, or 3 times accepted maturation diameter, is proposed. The mechanism of aneurysmal dilatation is unknown but appears to be a combination of excessive external remodeling, wall changes due to injury, and obstruction of outflow. Diagnosis of AV aneurysms is based on physical examination and ultrasound. Venography and cross-sectional imaging may assist and be required for the investigation of outflow stenosis. Treatment of pseudo aneurysms and true aneurysms of VA (AVA) is not evidence-based, but relies on clinical experience and available facilities. In many AVA, a conservative approach with surveillance is suitable, although intervals and modalities are unclear. Avoidance of rupture is imperative and preemptive treatment should aim for access preservation, ideally with avoidance of prosthetic materials. Different techniques of aneurysmorrhaphy are described with good results in published series. Although endovascular approaches and stenting are described with good short-term results, issues with cannulation of stented areas occur and, while possible, this is not recommended, and long-term access revision is recommended.

scholarly journals Learning and memory

1989 ◽  
Vol 8 (1) ◽  
pp. 12-24
Author(s):  
P. A. J. Ryke
Keyword(s):  
Short Term Memory ◽  
Cultural Learning ◽  
Long Term Memory ◽  
Latent Learning ◽  
Short Term ◽  
Term Memory ◽  
The One ◽  
Definition Of

Under various circumstances and in different species the outward expression of learning varies considerably, and this has led to the classification of different categories of learning. Just as there is no generally agreed on definition of learning, there is no one system of classification. Types of learning commonly recognized are: Habituation, sensitization, classical conditioning, operant conditioning, trial and error, taste aversion, latent learning, cultural learning, imprinting, insight learning, learning-set learning and instinct. The term memory must include at least two separate processes. It must involve, on the one hand, that of learning something and on the other, at some later date, recalling that thing. What lies between the learning and (he remembering must be some permanent record — a memory trace — within the brain. Memory exists in at least two forms: memory for very recent events (short-term) which is relatively labile and easily disruptable; and long-term memory, which is much more stable. Not everything that gets into short-term memory becomes fixed in the long-term store; a filtering mechanism selects things that might be important and discards the rest.

Rorschach Usefulness in Treatment Planning

2010 ◽  
Vol 31 (1) ◽  
pp. 70-89 ◽  
Author(s):  
Maria Concepcion Sendín
Keyword(s):  
Clinical History ◽  
Communication Style ◽  
Therapeutic Approaches ◽  
Short Term ◽  
Clinical Vignettes ◽  
Diagnostic Interviews ◽  
Weak Points ◽  
Motivation Level ◽  
Definition Of

To achieve a therapeutic design, we should examine three main information sources: clinical history, Rorschach test, and the subject’s communication style during the diagnostic interviews. We should study people from the perspective of their individuality and always consider groups of data, not isolated elements. Professionals should do this task by examining five basic areas: explicit symptoms, strong and weak points, motivation level, definition of short-term and long-term objectives, and available therapeutic approaches. Clinical vignettes from two different Rorschach protocols, Case 1, a 25-year-old man, and Case 2, a 30-year-old woman, are included in this article.

The Simplified Method for the Wave Loads Statistical Characteristics Estimation in Stationary Confused Seas

2004 ◽  
Author(s):  
I. F. Davydov ◽  
G. V. Egorov ◽  
V. V. Kozlyakov
Keyword(s):  
Three Dimensional ◽  
Correlation Coefficients ◽  
Statistical Characteristics ◽  
Wave Loads ◽  
Short Term ◽  
Shape Stability ◽  
Response Characteristics ◽  
Combined Stresses ◽  
Definition Of

Practically relevant procedures of construction of the short-term and long-term distributions of wave loads and combined stresses at two- and three-dimensional waves is based on the rather cumbersome schemes of definition of the standards “σyi”, effective periods “Tyie” and correlation coefficients “ryiyi” of wave loads “yi”. These calculations can be made more visible and essentially simplified on the basis of the shape stability of the doubly-normalized amplitude-frequency (AFC) and mutual-frequency response characteristics (MFRC). All specific features of these characteristics are determined by their maximum values and frequencies of maxima. In the report the convenient formulae for estimation of σyi, Tyie and ryiyj are derived, and graphs of functions, determining them, for different wave loads are plotted. These relations allow to reveal major influencing factors and use them for construction of the short-term and long-term spectra of wave loads and stresses for full transport ships (CB &gt; 0.75), including FPSO ships, for which non-linear and dynamic effects are expressed rather weakly.

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