Secondary Event

Secondary events are events that are not directly related to the accident. However, they are like contributing factors, in that they are indirectly related to the accident, 

Secondary events are events that are not directly related to the accident. However, they are like contributing fectors, in that they are indirectly related to the accident, and they help set up the accident. An example would be not locking the gates to a construction site and kids wandering onto the site and hurting themselves. 

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The events and causal factors chart for this incident is shown in Figure 7.9. The primary sequence of events is shown horizontally in bold boxes. Secondary events are shown in the other boxes, and conditions are in ovals. From the diagram three causal factors were identified and carried forward to the Root Cause Coding to establish the root causes of the causal factors. 

These may trigger secondary events, e.g. fires, toxic releases or further explosions. 

The fact that the initial setting process for magnesium oxychloride cements takes place without observable formation of either the 5 1 8 or the 3 1 8 phase is important. It indicates that formation of an amorphous gel structure occurs as the first step, and that crystallization is a secondary event which takes place from what is effectively a supersaturated solution (Urwongse Sorrell, 1980a). This implies that crystallization is likely to be extremely dependent upon the precise conditions of cementition, including temperature, MgO reactivity, heat build-up during reaction and purity of the components in the original cement mixture. 

There are a variety of process safety risks one needs to assess with chemical processes. In general, these risks will lead to an evaluation of the potential for the process to have precipitous changes in temperature and or pressure that lead to secondary events such as detonations, explosions, over pressurizations, fires, and so forth. The most cost-effective way of avoiding these sorts of risks is through the adoption of inherent safety principles. Inherent safety principles are very similar to and complementary to pollution prevention principles, where one attempts to use a hierarchy of approaches to avoid and/or reduce the risk of an adverse event. The reader is referred elsewhere to a more complete treatment of this important area of process design. ... 

Once the initial event occurs, secondary events occur at the cellular level that contribute to cell death. Regardless of the specific initiating event, the cellular processes that follow may be similar. Excitatory amino acids such as glutamate accumulate within the cells, causing intracellular calcium accumulation. Inflammation occurs and oxygen free radicals are formed ending in the common pathway of cell death. 

Einhellig and Rasmussen (17) reported that In addition to ferulic and p-coumaric acids, vanillic acid reduced chlorophyll content of soybean leaves but did not affect chlorophyll In grain sorghum fSorghum bicolor (L.) Moench.]. It Is not known whether these reported mechanisms are primary or secondary events In the Inhibition of plant growth by allelochemlcals. 

It has been suggested that mitochondrial injury was a late and possibly secondary event in mercury nephrotoxicity in rats [224], However, compromised mitochondrial bioenergetic function was later proposed to be one of the earliest intracellular effects of mercuric chloride in the production of nephrotoxicity [226, 227],... 

Domino effects—The triggering of secondary events, such as toxic releases, by a primary event, such as an explosion, such that the result is an increase in consequences or area of an effect zone. Generally only considered when a significant escalation of the original incident results sometimes known as a knock on event. 

Secondary event sequences are presented at different levels. 

According to Kennedy et aL (1980), these observations suggest that the transformed clones do not occur as the direct consequence of carcinogen treatment. Rather, these authors propose a two-step model to explain the results. The initial change induced by the carcinogen apparently occurs in a large number, perhaps all, of the cells. This change does not result directly in the transformation of the cells but increases the probability of their transformation as a rare, secondary event (Kennedy, 1984). 

The individual isotope systems differ in the objects that they can date, the details of how they are measured, and the specifics of how they are applied. Some systems are best suited to date fractionation events based on volatility. Others are best suited to date igneous processes. Still others are most useful for secondary events. Together they provide the keys to unlocking the time history of the solar system. In Chapter 9, we will summarize the current state of knowledge of the chronology of the solar system obtained from these radiochronometers. 

Secondary events. These are the changes that may occur in cells exposed to toxic compounds following the primary events. 

The major secondary events are changes in membrane structure and permeability, changes in the cytoskeleton, mitochondrial damage, depletion of ATP and other cofactors, changes in Ca2+ concentration, DNA damage and poly ADP-ribosylation, lysosomal destabilization, stimulation of apoptosis, and damage to the endoplasmic reticulum. 

In some cases, these may be primary events in other situations, they may follow primary events or follow sequentially from another secondary event. 

Earlier in this chapter we discussed the critical secondary events occurring following the primary mechanisms of toxicity. Depending on the severity, these events can be reversible or can lead to cell death. 

Secondary events result from primary events, for example, changes in membrane structure/permeability, mitochondrial damage, and lysosomal destabilization. Tertiary events are final observable manifestations, for example, fatty change and phospholipidosis, apoptosis, blebbing, and necrosis. 

Lipolysis is considered to be an important biochemical event during cheese ripening and the current knowledge have been discussed in detail (Collins et al., 2003, 2004 McSweeney and Sousa, 2000). The formation of short-chain FFAs by the lipolysis of milk fat by lipases is a desirable reaction in many cheese types (e.g., mold-ripened cheeses). The catabolism of FFAs, which is a secondary event in the ripening process, leads to the formation of volatile flavor compounds such as lactones, thioesters, ethyl esters, alkanols, and hydroxyl fatty acids. The contributions of lipolysis to the flavor of bacterially ripened cheeses are limited. 

Finally, in addition to the issues of costs and secondary events, treatment is also lacking for many more at-risk patients who cannot undergo successful angioplasty. These patients, who may have either diffuse, nonstentable, bifurcated lesions, or multivessel disease (i.e., diabetics), are not benefiting as much from DES, and improved treatments here also remain a clear clinical need. Often there is a systemic and local activation of the immune response, followed by a consequent local vascular incident. The role of the systemic immune response in these individuals, as well as in cardiovascular patients in general, is evidenced by the numerous reports of correlation of disease with increases in plasma markers such as CRB tumor necrosis factor, and even circulating white cell counts (87-89). 

The graphical structure of the fault tree enables the primary causes and secondary events that produce the hazards to be combined. It is then possible to compare the relative contributions of the different events to the probability of the hazardous outcome by employing the probability of occurrence of causes and events on the fault tree. 

ALP rises relatively early and settles very late but the peak-to-baseline ratio is less than 2. This is because it shows sludging of the bile duct as a secondary event to the hepatocellular damage. 

G protein subunits into a and [iy subunits. Both the a and [fy subunits may elicit secondary events such as the activation or inhibition of the catalytic unit of adenylate cyclase. 

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