scholarly journals Bakerian lecture.―On the statistical and thermodynamical relations of radiant energy

1909 ◽  
Vol 83 (560) ◽  
pp. 82-95 ◽  
Keyword(s):  
Random Distribution ◽  
Small Deviation ◽  
Laws Of Nature ◽  
Radiant Energy ◽  
Direct Perception ◽  
Mechanical Philosophy ◽  
Direct Knowledge ◽  
Ancient Times ◽  
The Mean ◽  
The Individual

It was surmised by a prominent school of thought in ancient times, it become absorbed into the mechanical philosophy of Newton, and it was at length established by the experiments and reasonings of Dalton and his contemporaries, that matter is not divisible without limit, but is constituted of an aggregate of discrete entities, all alike for the same homogeneous substance, and naturally extremely minute compared with our powers of direct perception. The smallest portion of matter which we can manipulate (at any rate until very recently) consists of a vast assemblage of molecules, of independent self-existing systems which exert dynamical influences on each other. The direct knowledge of matter that mankind can acquire is a knowledge of the average behaviour and relations of the crowd of molecules. The sentient intelligence with perceptions of space and time minute enough to examine the individual molecules, each of them -would probably appear as a cosmos in itself, influencing and influenced by others,—not unlike stars in a firmament. The observed laws of nature are thus laws of averages—are statistical relations. Yet they are for practical purposes exact. To illustrate this in a way that will presently be of use let us imagine a row of urns whose apertures are of different areas, and let us consider how N objects will be distributed at random among them, assuming that the chance of an object getting into an urn is proportional to the area of its aperture, and is otherwise indifferent as regards them all. If the number of objects is not very large in comparison with the number of urns, no direct law of numbers emerges in this random distribution: though by the doctrine of probabilities we may calculate definitely the relative numbers of times that the various distributions will occur in a vast total number of cases, and this will represent the chances of recurrence of these distributions, the most likely arrangements are those ranging close around the equable distribution, in which the contents of the urns are proportional to their apertures. Those far removed therefrom are much less likely. "When the number N is very great, a relatively small deviation from the equable distribution has an almost negligible chance of occurring. Equable distribution then assumes the aspect of a rigid law; nevertheless occasionally in an soon it will he widely departed from. The abstract laws governing the extent and distribution of the various kinds of deviations from the mean distribution constitute an important part of the theory of statistics, first explored and developed by J. Bernoulli.

Measurement of feature clustering in images

1990 ◽  
Vol 48 (1) ◽  
pp. 552-553
Author(s):  
John C. Russ
Keyword(s):  
Spatial Distribution ◽  
Random Distribution ◽  
Nearest Neighbor ◽  
Mean Value ◽  
Feature Clustering ◽  
Spatial Coordinates ◽  
Distribution Of Points ◽  
The Mean ◽  
The Individual ◽  
Nearest Neighbor Distances

The spatial distribution of features in an image is often interesting, but not simple to characterize. Mapping of the image into a different space (e.g., Fourier or Hough) offers direct information on various regularities in feature spacing or alignment, but does not deal directly with the individual features. Two other approaches are available; each has advantages and drawbacks, which are discussed here.Schwarz & Exner determine the spatial coordinates of the centroids of features, and sort them to locate the nearest neighbor for each feature present, constructing a distribution plot of the frequency of nearest neighbor distances. Figures 1 and 2 show an example. The three fields in Figure 1 contain, respectively, features which are well-spaced from each other, randomly arranged on the plane, and clustered together. For the random distribution of points, the histogram of nearest neighbor distances is a Poisson distribution, and the mean value is 0.5/NA1/2, where NA is the number of features divided by the area of the image.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

SERUM THYROTROPHIN AND THE RESPONSE TO THYROTROPHIN RELEASING HORMONE IN SYMPTOMLESS AUTOIMMUNE THYROIDITIS AND IN BORDERLINE AND OVERT HYPOTHYROIDISM

1974 ◽  
Vol 75 (2) ◽  
pp. 274-285 ◽  
Author(s):  
A. Gordin ◽  
P. Saarinen ◽  
R. Pelkonen ◽  
B.-A. Lamberg
Keyword(s):  
Autoimmune Thyroiditis ◽  
Elevated Serum ◽  
Mean Value ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
The Mean ◽  
The Individual ◽  
Serum Tsh

ABSTRACT Serum thyrotrophin (TSH) was determined by the double-antibody radioimmunoassay in 58 patients with primary hypothyroidism and was found to be elevated in all but 2 patients, one of whom had overt and one clinically borderline hypothyroidism. Six (29%) out of 21 subjects with symptomless autoimmune thyroiditis (SAT) had an elevated serum TSH level. There was little correlation between the severity of the disease and the serum TSH values in individual cases. However, the mean serum TSH value in overt hypothyroidism (93.4 μU/ml) was significantly higher than the mean value both in clinically borderline hypothyroidism (34.4 μU/ml) and in SAT (8.8 μU/ml). The response to the thyrotrophin-releasing hormone (TRH) was increased in all 39 patients with overt or borderline hypothyroidism and in 9 (43 %) of the 21 subjects with SAT. The individual TRH response in these two groups showed a marked overlap, but the mean response was significantly higher in overt (149.5 μU/ml) or clinically borderline hypothyroidism (99.9 μU/ml) than in SAT (35.3 μU/ml). Thus a normal basal TSH level in connection with a normal response to TRH excludes primary hypothyroidism, but nevertheless not all patients with elevated TSH values or increased responses to TRH are clinically hypothyroid.

Methods for assessing territory pollution by oil or petroleum product spills

2020 ◽  
pp. 140-146
Author(s):  
S. I. Chelombitko ◽  
V. V. Piven
Keyword(s):  
Oil And Gas ◽  
Radiant Energy ◽  
Petroleum Products ◽  
Individual Characteristics ◽  
Oil And Gas Fields ◽  
Northern Regions ◽  
Negative Impacts ◽  
The Individual ◽  
Destructive Processes ◽  
Gas Fields

During the development of oil and gas fields and transportation of hydrocarbons, the ecology of regions is subject to various negative impacts. The most severe consequences for the environment are caused by accidental spills of oil or petroleum products, which occur due to through damage to pipelines. Polluted territories are subject to mandatory reclamation in accordance with government regulations and industry regulations. However, despite the measures taken by the administrations of the northern regions to increase the rate of reclamation of damaged territories in recent years, there has been a trend of growth of areas contaminated with hydrocarbons.Various remediation technologies that have been tested in warm and temperate climates are not very effective in regions with permafrost. Pollution of the daytime surface with oil or petroleum products leads to an increase in the absorption of the sun's radiant energy, the growth of the seasonal thaw layer and the development of destructive processes for the territory. To achieve a positive effect as a result of rehabilitation measures, it is necessary to take into account the individual characteristics of the territory and the extent of its pollution.

Stochastic homogenization and macroscopic modelling of composites and flow through porous media

2002 ◽  
pp. 337-378 ◽  
Author(s):  
Jozef Telega ◽  
Wlodzimierz Bielski
Keyword(s):  
Porous Medium ◽  
Random Distribution ◽  
Flow Through Porous Media ◽  
Macroscopic Models ◽  
Linear Elastic ◽  
Multi Scale ◽  
Convergence Method ◽  
Flow Through ◽  
The Mean ◽  
Random Porous Medium

The aim of this contribution is mainly twofold. First, the stochastic two-scale convergence in the mean developed by Bourgeat et al. [13] is used to derive the macroscopic models of: (i) diffusion in random porous medium, (ii) nonstationary flow of Stokesian fluid through random linear elastic porous medium. Second, the multi-scale convergence method developed by Allaire and Briane [7] for the case of several microperiodic scales is extended to random distribution of heterogeneities characterized by separated scales (stochastic reiterated homogenization). .

Quality of Life for Children with Persistent Sinonasal Symptoms

2003 ◽  
Vol 128 (1) ◽  
pp. 17-26 ◽  
Author(s):  
David J. Kay ◽  
Richard M. Rosenfeld
Keyword(s):  
Quality Of Life ◽  
Clinical Care ◽  
Longitudinal Change ◽  
Good Test ◽  
Routine Clinical Care ◽  
Before And After ◽  
The Mean ◽  
The Individual ◽  
Sinonasal Symptoms

OBJECTIVE: The goal was to validate the SN-5 survey as a measure of longitudinal change in health-related quality of life (HRQoL) for children with persistent sinonasal symptoms. DESIGN AND SETTING: We conducted a before and after study of 85 children aged 2 to 12 years in a metropolitan pediatric otolaryngology practice. Caregivers completed the SN-5 survey at entry and at least 4 weeks later. The survey included 5 symptom-cluster items covering the domains of sinus infection, nasal obstruction, allergy symptoms, emotional distress, and activity limitations. RESULTS: Good test-retest reliability ( R = 0.70) was obtained for the overall SN-5 score and the individual survey items ( R ≥ 0.58). The mean baseline SN-5 score was 3.8 (SD, 1.0) of a maximum of 7.0, with higher scores indicating poorer HRQoL. All SN-5 items had adequate correlation ( R ≥ 0.36) with external constructs. The mean change in SN-5 score after routine clinical care was 0.88 (SD, 1.19) with an effect size of 0.74 indicating good responsiveness to longitudinal change. The change scores correlated appropriately with changes in related external constructs ( R ≥ 0.42). CONCLUSIONS: The SN-5 is a valid, reliable, and responsive measure of HRQoL for children with persistent sinonasal symptoms, suitable for use in outcomes studies and routine clinical care.

scholarly journals VARIABILITY OF EVOLUTIONARY RATES OF DNA

Genetics ◽  
1986 ◽  
Vol 113 (4) ◽  
pp. 1077-1091
Author(s):  
John H Gillespie
Keyword(s):  
Dna Sequences ◽  
Significant Excess ◽  
Ergodic Markov Chain ◽  
The Third ◽  
Markov Chain Models ◽  
Rate Of Molecular Evolution ◽  
The Mean ◽  
Nuclear Loci ◽  
The Individual ◽  
Evolution Of Proteins

ABSTRACT A statistical analysis of DNA sequences from four nuclear loci and five mitochondrial loci from different orders of mammals is described. A major aim of the study is to describe the variation in the rate of molecular evolution of proteins and DNA. A measure of rate variability is the statistic R, the ratio of the variance in the number of substitutions to the mean number. For proteins, R is found to be in the range 0.16 < R < 35.55, thus extending in both directions the values seen in previous studies. An analysis of codons shows that there is a highly significant excess of double substitutions in the first and second positions, but not in the second and third or first and third positions. The analysis of the dynamics of nucleotide evolution showed that the ergodic Markov chain models that are the basis of most published formulas for correcting for multiple substitutions are incompatible with the data. A bootstrap procedure was used to show that the evolution of the individual nucleotides, even the third positions, show the same variation in rates as seen in the proteins. It is argued that protein and silent DNA evolution are uncoupled, with the evolution at both levels showing patterns that are better explained by the action of natural selection than by neutrality. This conclusion is based primarily on a comparison of the nuclear and mitochondrial results.

Evaluation of retinal inflammatory biomarkers after intravitreal steroid implant and Ranibizumab injection in diabetic macular edema

2021 ◽  
pp. 112067212110294
Author(s):  
Ilkay Kilic Muftuoglu ◽  
Ecem Onder Tokuc ◽  
Fatma Sümer ◽  
V Levent Karabas
Keyword(s):  
Macular Edema ◽  
Diabetic Macular Edema ◽  
Outer Nuclear Layer ◽  
Plexiform Layer ◽  
Retinal Layer ◽  
Treatment Naïve ◽  
The Mean ◽  
The Individual ◽  
Inflammatory Component

Purpose: To compare the efficacy of intravitreal (IV) ranibizumab (IVR) injection with IV dexamethasone implant (IVDEX) in treatment naive diabetic macular edema (DME) patients with inflammatory component. Materials and methods: Treatment naive DME eyes with subfoveal neurosensorial detachment (SND) and hyperreflective spots (HRS) were treated either three loading doses of IVR (18 eyes) or one dose of IVDEX (19 eyes). Central macular thickness (CMT), height of SND, the number of HRSs scattered on the individual retinal layers and photoreceptor integrity were assessed using spectral domain- optical coherence tomography scans over 3-months follow-up. Results: The mean change in best-corrected visual acuity (BCVA) was −0.11 ± 0.08 logMAR in IVDEX group and −0.04 ± 0.06 logMAR in IVR group at 1-month ( p = 0.011). IVDEX group showed statistically significant more increase in BCVA compared to those receiving IVR injections at 2-months ( p = 0.004) and 3-months ( p = 0.017) visits. Compared to baseline, the number of total HRSs and the number of HRSs at each individual inner retinal layer significantly decreased in both groups at all follow-up visits. However, IVDEX group showed more decrease in the total number of HRSs at 2- and 3-months ( p < 0.001 at 2-months, and p = 0.006 at 3-months) and in the mean number of HRSs located at inner nuclear layer–outer plexiform layer level ( p = 0.016 at 1-month, p < 0.001 at 2-months, and p < 0.001 at 3-months). After treatment, the number of HRSs on the outer nuclear layer showed some non-significant increase in both groups. Conclusion: HRSs tended to migrate from inner retina to the outer retina in DME eyes by treatment. Dexamethasone seemed to be more effective option in such cases with inflammatory component.

scholarly journals Effects of the Carrier Phrase on Word Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Vol 31 (06) ◽  
pp. 412-441 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Abstract Background In the 1950s, with monitored live voice testing, the vu meter time constant and the short durations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrier phrase amplitude to monitor (indirectly) the presentation level of the words. This practice continues with recorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrase has on word recognition performance needs clarification, which is the topic of this study. Purpose Recordings of Northwestern University Auditory Test No. 6 by two female speakers were used to compare word recognition performances with and without the carrier phrases when the carrier phrase and test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1 speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in the target word with the largest root mean square amplitude was used to equate the target word amplitudes. Research Design A quasi-experimental, repeated measures design was used. Study Sample Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average [PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participated in two, one-hour sessions. Data Collection and Analyses Each listener had 16 listening conditions (2 speakers × 2 carrier phrase conditions × 4 presentation levels) with 100 randomized words, 50 different words by each speaker. Each word was presented 8 times (2 carrier phrase conditions × 4 presentation levels [YNH, 0- to 24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8, 25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated between speakers and randomized by blocks of the four conditions. Central tendency and repeated measures analyses of variance statistics were used. Results With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3% (OHL) significantly better with the carrier phrase than without the carrier phrase. These differences were in part attributed to the distortion of some words caused by the excision of the words from the carrier phrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditions by both listener groups were not significantly different, except for one condition (YNH listeners at 8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) than for the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for the VA-2 speaker. Although the mean results were clear, the variability in performance differences between the two carrier phrase conditions for the individual participants and for the individual words was striking and was considered in detail. Conclusion The current data indicate that word recognition performances with and without the carrier phrase (1) were different when the carrier phrase and target word were produced in the same utterance with poorer performances when the target words were excised from their respective carrier phrases (VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independent utterances (VA-2 speaker).

The Perennial Problem of Variability In Adenosine Triphosphate (ATP) Tests for Hygiene Monitoring Within Healthcare Settings

2015 ◽  
Vol 36 (6) ◽  
pp. 658-663 ◽  
Author(s):  
Greg S. Whiteley ◽  
Chris Derry ◽  
Trevor Glasbey ◽  
Paul Fahey
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Test Point ◽  
Dilution Series ◽  
Healthcare Settings ◽  
Speed Of Response ◽  
Numerical Scale ◽  
Dilution Step ◽  
The Mean ◽  
The Individual

OBJECTIVETo investigate the reliability of commercial ATP bioluminometers and to document precision and variability measurements using known and quantitated standard materials.METHODSFour commercially branded ATP bioluminometers and their consumables were subjected to a series of controlled studies with quantitated materials in multiple repetitions of dilution series. The individual dilutions were applied directly to ATP swabs. To assess precision and reproducibility, each dilution step was tested in triplicate or quadruplicate and the RLU reading from each test point was recorded. Results across the multiple dilution series were normalized using the coefficient of variation.RESULTSThe results for pure ATP and bacterial ATP from suspensions ofStaphylococcus epidermidisandPseudomonas aeruginosaare presented graphically. The data indicate that precision and reproducibility are poor across all brands tested. Standard deviation was as high as 50% of the mean for all brands, and in the field users are not provided any indication of this level of imprecision.CONCLUSIONSThe variability of commercial ATP bioluminometers and their consumables is unacceptably high with the current technical configuration. The advantage of speed of response is undermined by instrument imprecision expressed in the numerical scale of relative light units (RLU).Infect Control Hosp Epidemiol2015;00(0):1–6

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