A Rapid Method for Postmortem Vitreous Chemistry—Deadside Analysis

Vitreous fluid is commonly collected for toxicological analysis during forensic postmortem investigations. Vitreous fluid is also often analyzed for potassium, sodium, chloride and glucose for estimation of time since death, and for the evaluation of electrolyte imbalances and hyperglycemia, respectively. Obtaining such results in the early phase of a death investigation is desirable both in regard to assisting the police and in the decision-making prior to the autopsy. We analyzed vitreous fluid with blood gas instruments to evaluate/examine the possible impact of different sampling and pre-analytical treatment. We found that samples from the right and left eye, the center of the eye as well as whole vitreous samples gave similar results. We also found imprecision to be very low and that centrifugation and dilution were not necessary when analyzing vitreous samples with blood gas instruments. Similar results were obtained when analyzing the same samples with a regular multi-analysis instrument, but we found that such instruments could require dilution of samples with high viscosity, and that such dilution might impact measurement accuracy. In conclusion, using a blood gas instrument, the analysis of postmortem vitreous fluid for electrolytes and glucose without sample pretreatment produces rapid and reliable results.

Contraction bias in temporal estimation

When asked to compare the perceptual features of two serially presented objects, participants are often biased to over- or under-estimate the difference in magnitude between the stimuli. Overestimation occurs consistently when a) the two stimuli are relatively small in magnitude and the first stimulus is larger in magnitude than the second; or b) the two stimuli are relatively large in magnitude and the first stimulus is smaller in magnitude than the second; underestimation consistently occurs in the complementary cases. This systematic perceptual bias, known as the contraction bias, was demonstrated for a multitude of perceptual features and in various modalities, but it is yet unknown whether it also exists in the temporal domain. Here, we tested whether estimation of time-duration is affected by the contraction bias. In each trial of three experiments (n=20 each), participants compared the duration of two visually presented stimuli. Findings revealed over- and under-estimation effects as predicted by the contraction bias. In addition, we found that the bias was asymmetrical, indicating that, in some cases, the subjective center of the distribution was shifted to the left. Here, we discuss this asymmetry and describe how these findings can be explained via a Bayesian inference framework.

Estimation of time utilized in suturing of oral flaps post-surgical wisdom teeth removal using Negus knot pusher instrument (a comparative study)

Wisdom teeth were the most common teeth affected among the rest of the teeth, these teeth need accurate evaluation and diagnosis, surgical removal of impacted wisdom needs time for incision, bone removal and suture, so the use of any instrument helps to reduce this time is essential. Objective The objectives of this study were to estimate the time needed for the suture of oral flaps post-surgical removal of the lower wisdom teeth by using Negus knot pusher and compare it with the time used for stitching in conventional manual holding single stitching. Material and Methods: Data had been collected from thirty patients through history, clinical examination and radiographic assessment, followed by classical surgical removal performed on the same principles for all patients, at the suture level patients divided arbitrarily into two groups, control group 15 patients and 15 patients Negus pusher group, using Negus knot pusher, which is usually used to hold the stitch and stop bleeding post tonsillectomy operations by ligation, time elapsed for suturing with knot tying is calculated for both groups. Results: Among the 30 patients incorporated in the clinical study, control group mean was (1 minutes and 11 seconds and 70 milliseconds) while for the pusher group was (1 minutes and 32 seconds and 57 milliseconds), the comparison by means of T-test was not significant with the (0.424) value. Conclusion: the Negus pusher instrument can be used for the knotting stiches post wisdom teeth removal as an auxiliary tool and the time can be shortened by the use of a modified handling technique and more satisfaction for patients. Keywords Time; Suturing; Wisdom teeth; Negus knot pusher.

Individual and age-specific perceptions of time by adults

The paper presents an experimental research of individual, age and gender specifics of time perception by adults from 18 to 75 years old (750 people). The methodological techniques used are: estimation, measuring and reproduction of time intervals within one minute. It was shown that when perceiving equal in value time intervals the respondents reveal opposite individual tendencies, manifested either in over- or under-estimation of time intervals, or in their under- or over-measuring, or in the absence of any particular tendency. Age and gender differences in the perception of time by adults were revealed. An analysis of the obtained data showed the presence of continuous micro-age shifts within the age range of 18-75 years, which is characterized by a rather complex, contradictory structure in the development of features of time intervals perception. On the border of early and middle adulthood at age 26, there is a slight increase in the accuracy of time interval estimation and measurement. On the border of middle and late adulthood, at age 45, there is already a sharp decline in the accuracy of time perception. Whether these age periods can be called critical or transitional cannot be unequivocally stated. Experimental data show that we cannot regard adulthood as a stationary, fully stabilized state where nothing happens anymore or as a period of gradual unfolding of involutionary processes only.

Improved estimation of time-varying reproduction numbers at low case incidence and between epidemic waves

We construct a recursive Bayesian smoother, termed EpiFilter, for estimating the effective reproduction number, R, from the incidence of an infectious disease in real time and retrospectively. Our approach borrows from Kalman filtering theory, is quick and easy to compute, generalisable, deterministic and unlike many current methods, requires no change-point or window size assumptions. We model R as a flexible, hidden Markov state process and exactly solve forward-backward algorithms, to derive R estimates that incorporate all available incidence information. This unifies and extends two popular methods, EpiEstim, which considers past incidence, and the Wallinga-Teunis method, which looks forward in time. We find that this combination of maximising information and minimising assumptions significantly reduces the bias and variance of R estimates. Moreover, these properties make EpiFilter more statistically robust in periods of low incidence, where several existing methods can become destabilised. As a result, EpiFilter offers improved inference of time-varying transmission patterns that are advantageous for assessing the risk of upcoming waves of infection or the influence of interventions, in real time and at various spatial scales.