Adventitious Events Research Articles

An assessment of the immune status of some stone quarry workers in Ondo state, Nigeria.

Stone quarry activities in Nigeria are mostly unregulated such that the workers in these quarries are continuously exposed to the inhalation of silica dust. It has been observed that silica dust particles negatively impact the health of stone quarry workers which usually manifest as respiratory difficulties, asthma-like illnesses and other adventitious events of the lungs. The study was designed to evaluate the probable immunological impact of silica dust inhalation from stone crushing by workers. Blood samples were collected from consenting workers and analyzed for total white blood cells and their subsets. Absolute CD4 cells numbers were also determined. The results indicated that neutrophils and eosinophils numbers increased significantly (P < .05) and CD4 counts declined significantly (P < .001). Alteration in these proportions is a pointer to the injurious impact of silica dust on the immune system of these workers. The findings in this study should spur actions in the education of these workers on the need for the use of proper personal protection equipment and the establishment of a scheme to periodically carry out a health assessment check to identity those at most risk of developing chronic illnesses.

The procurement of quartz as a tool stone

The archaeological data suggest that the procurement of quartz was often times not a random or adventitious event, but rather an organized task of exploitation targeting geologic exposures which afforded good quality material in terms of composition, form, and quantity. In the absence of professionally collected data on quartz quarries or quartz extraction areas, an inferential approach can be substituted to afford some clarity to the issue. The study of patterning in recorded archaeological sites with dominant quartz tool stone assemblages can provide the means for identifying the geologic source areas and assist in precisely locating procurement areas.

Computerized Lung Sound Screening for Pediatric Auscultation in Noisy Field Environments.

Chest auscultations offer a non-invasive and low-cost tool for monitoring lung disease. However, they present many shortcomings, including inter-listener variability, subjectivity, and vulnerability to noise and distortions. This work proposes a computer-aided approach to process lung signals acquired in the field under adverse noisy conditions, by improving the signal quality and offering automated identification of abnormal auscultations indicative of respiratory pathologies. The developed noise-suppression scheme eliminates ambient sounds, heart sounds, sensor artifacts, and crying contamination. The improved high-quality signal is then mapped onto a rich spectrotemporal feature space before being classified using a trained support-vector machine classifier. Individual signal frame decisions are then combined using an evaluation scheme, providing an overall patient-level decision for unseen patient records. All methods are evaluated on a large dataset with 1000 children enrolled, 1-59 months old. The noise suppression scheme is shown to significantly improve signal quality, and the classification system achieves an accuracy of 86.7% in distinguishing normal from pathological sounds, far surpassing other state-of-the-art methods. Computerized lung sound processing can benefit from the enforcement of advanced noise suppression. A fairly short processing window size ( s) combined with detailed spectrotemporal features is recommended, in order to capture transient adventitious events without highlighting sharp noise occurrences. Unlike existing methodologies in the literature, the proposed work is not limited in scope or confined to laboratory settings: This work validates a practical method for fully automated chest sound processing applicable to realistic and noisy auscultation settings.

Stability and energy of low current surface discharges on wet surfaces

Low current discharges are of concern in the context of predicting the lifetime of outdoor polymeric insulators. The nature of ac surface discharges changes markedly between peak currents of 0.5 mA and 10 mA: the electrical characteristics typically changing from unstable to stable behavior when the peak current increases above 1 mA. This change is important because of the implications of energy transfer between the discharge and the underlying material surface, and resulting changes to ageing mechanisms. In this paper, tests with artificial wind and rain have been conducted to investigate the processes by which unstable discharges become stable. Results show that under the impact of wind and rain, low current (<; 1 mA) unstable discharges can transform to stable discharges. Discharge length compression was observed for the stable dry-band discharges in the current range between 5 mA and 10 mA under similar experimental conditions. Analysis of electrical energy in the discharge indicates that the energy density per cycle rises significantly during both the unstable to stable discharge transition, and during discharge compression. It is clear therefore that ageing as a result of surface discharges on outdoor insulation must be thought of as a dynamic process, rather than one in equilibrium. The implication is that short-term adventitious events may control insulator life expectancy rather than long-term 'average' conditions.

High-precision isothermal titration calorimetry with automated peak-shape analysis.

Isothermal titration calorimetry (ITC) is a powerful classical method that enables researchers in many fields to study the thermodynamics of molecular interactions. Primary ITC data comprise the temporal evolution of differential power reporting the heat of reaction during a series of injections of aliquots of a reactant into a sample cell. By integration of each injection peak, an isotherm can be constructed of total changes in enthalpy as a function of changes in solution composition, which is rich in thermodynamic information on the reaction. However, the signals from the injection peaks are superimposed by the stochastically varying time-course of the instrumental baseline power, limiting the precision of ITC isotherms. Here, we describe a method for automated peak assignment based on peak-shape analysis via singular value decomposition in combination with detailed least-squares modeling of local pre- and postinjection baselines. This approach can effectively filter out contributions of short-term noise and adventitious events in the power trace. This method also provides, for the first time, statistical error estimates for the individual isotherm data points. In turn, this results in improved detection limits for high-affinity or low-enthalpy binding reactions and significantly higher precision of the derived thermodynamic parameters.

Postharvest Survey of Spring Wheat Fields Initially Assessed for Gene Flow

ABSTRACTRecent research has addressed the potential for gene flow in wheat (Triticum aestivum L.). However, there is scant information on the fate of introgressed genes in the subsequent crop rotation. The objective of this study was to quantify spring wheat volunteers potentially arising from gene flow. A total of 152 wheat fields that had been used to measure gene flow at distances of up to 10 km were surveyed for blue aleurone volunteers for 3 yr postharvest. No blue aleurone seed was detected in samples from the 152 fields surveyed. A single blue aleurone volunteer plant was detected in a pollen donor field subsequently sown to wheat in the third year postharvest. The absence of blue aleurone wheat volunteers in the postharvest crop rotation was not unexpected as only four of the original 152 fields had shown evidence of gene flow. Under the environmental and crop management practices encountered in this study, the risk of a gene flow‐based adventitious event in spring wheat being detected at significant levels in subsequent crops appears low.

The buccale puzzle: The symbiotic nature of endogenous infections of the oral cavity.

The indigenous, 'normal', microflora causes the majority of localized infectious diseases of the oral cavity (eg, dental caries, alveolar abscesses, periodontal diseases and candidiasis). The same microflora also protects the host from exogenous pathogens by stimulating a vigorous immune response and provides colonization resistance. How can a microflora that supports health also cause endogenous oral disease? This paradoxical host-symbiont relationship will be discussed within the dynamic of symbiosis.Symbiosis means 'life together' - it is capable of continuous change as determined by selective pressures of the oral milieu. Mutualistic symbiosis, where both the host and the indigenous microflora benefit from the association, may shift to a parasitic symbiosis, where the host is damaged and the indigenous microflora benefit. Importantly, these are reversible relationships. This microbial dynamism, called amphibiosis, is the essential adaptive process that determines the causation of endogenous oral disease by a parasitic microflora or the maintenance of oral health by a mutualistic microflora.Complex microbial consortiums, existing as a biofilm, usually provide the interfaces that initiate and perpetuate the infectious assault on host tissue. The ecology of the various oral microhabitats is critical for the development of the appropriate selecting milieux for pathogens. The microbiota associated with dental caries progression is primarily influenced by the prevailing pH, whereas periodontal diseases and pulpal infection appear to be more dependent on redox potential. Candidiasis results from host factors that favour yeast overgrowth or bacterial suppression caused by antibiotics. Oral health or disease is an adventitious event that results from microbial adaptation to prevailing conditions; prevention of endogenous oral disease can occur only when we realize that ecology is the heart of these host-symbiont relationships.

Distributing Adventitious Outcomes: Social Norms, Egocentric Martyrs, and the Effects on Future Relationships

Research on the distribution of resources typically focuses on anticipated outcomes. This paper investigates the social norms people use to distribute adventitious (unanticipated) outcomes. Participants in this study read a scenario where either they, or the person they were with (an acquaintance or a friend), received either an unexpected gain or loss which was or was not easily divisible. Participants were then asked to continue the story by describing what they believed would happen after the adventitious event. We measured if and how the outcome was divided between the two individuals involved as well as subjects’ and an outside observer's perceptions of the fairness of these divisions and any expectations they had about the effect of the event on the quality of the relationship between the two. Results suggest that people endorse a “losers weepers” norm more often than they do a “finders keepers” or “share and share alike” (equality) norm, although all were endorsed. Egocentric distributions and expectations permeated the story continuations. Although participants frequently suggest that they would share gains, they also expected that their sacrifices (sharing their own gain or in another's loss) would help improve the future relationship between the two more than would similar sacrifices by the other (i.e., they were often egocentric martyrs). Friendship and the divisibility of the outcome also affected allocation rules and expectations for the future relationship. The discussion highlights the irony associated with the finding that when an adventitious gain is not shared with another, the future relationship between the two is expected to be less positive. Thus, adventitious outcomes (and gains in particular) can be a double-edged sword.

MU switch region deletion is associated with both T cell independent and T cell dependent responses

Isotype switching is a process by which immunoglobulin variable gene regions initially proximal to and expressed with the mu constant region gene (C μ) can rearrange downstream to other constant region genes. Thus the same antigen binding site can be expressed with each of the other constant region isotypes and perform the full panoply of effector functions. Although isotype switching is thought to involve highly reiterated ‘switch site’ sequences located 5' to constant region genes, the exact role of these switch sites is unknown. It has been reported that prior to switching, the ‘donor’ switch site 5' of C μ occasionally undergoes deletions, but it is not known whether this is an adventitious event or one which predisposes to or prevents isotype switching. Since T cell independent (TI) immune responses are dominated by IgM while T cell dependent (TD) responses are associated with switching to IgG, we have examined the state of the mu switch site in 51 IgM-producing hybridomas isolated from a variety of TI and TD responses. Although more hybridomas from the TI responses studied exhibited S μ deletions, deletion of S μ also occurred in hybridomas isolated from TD responses. Analysis of a well-characterized clonally related subset of IgM hybridomas also revealed that mu switch region deletion can be associated with the productive allele.

Phosphorylation-dephosphorylation of apolipoprotein B

Publisher Summary There is little doubt of the physiologic importance of apolipoprotein B (apoB). In addition to being essential for the secretion of very low-density lipoprotein (VLDL), apoB plays a fundamental role in targeting cholesterol, as a component of LDL, to tissues via specific high-affinity receptors. Although there are sufficient data demonstrating the physiological and pathophysiologic importance of apoB, little is known about its structure, sequence, and posttranslational modifications. Phosphorylation of little B is an exciting new development. The finding that phosphoserine accounts for at least 20% of the 32 P that is present in little B, whereas similar analysis of phosphatidylserine does not yield phosphoserine, strongly argues against the idea that the phosphoserine is because of contamination with phospholipid. Preliminary studies suggest that little B is poly phosphorylated, further suggesting that the phosphorylation is not an adventitious event. However, apoB is an intricate, fastidious protein and one must be cautious when interpreting results of its behavior. It is because of these problems that many are deterred from investigating apoB structure and metabolism. Yet, there is little doubt about the physiologic importance of apoB.

An objective parallel evaluator of segmentation/Classification performance for multiple systems

A major difficulty in the development of methodologies for segmentation and classification in automatic recognition of continuous speech is the determination of objective, reliable performance statistics. Compounding this difficulty is the large amount of data necessary to make reasonably accurate performance estimates. The system to be described provides for concurrent objective evaluation of up to five independent segmentation/classification methods against a single, carefully transcribed referent. A basic assumption of the evaluator is that the systems to be compared, as well as the referent, can each use the same digital data as input. Violation of this assumption would lead to time-shift errors, and objective comparison among systems would be exceedingly difficult. For segmentation, the evaluator provides first-order statistics, at the phonetic, class and summary levels, in the form of highly concise tables for the following four types of errors: 1) Missed events; 2) Adventitious events; 3) Misplaced events; and 4) Adventitious and misplaced events. For classification, first-order statistics are derived in the form of confusion matrices at the phonetic, class and summary levels. While the system is still in the developmental process, it is operational and currently used. Examples of output will be presented.