Effects Of Changes In Intensity Research Articles

Coarse-to-fine registration and time-intensity curves constraint for liver DCE-MRI synthesis

Image registration plays a crucial role in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), used as a fundamental step for the subsequent diagnosis of benign and malignant tumors. However, the registration process encounters significant challenges due to the substantial intensity changes observed among different time points, resulting from the injection of contrast agents. Furthermore, previous studies have often overlooked the alignment of small structures, such as tumors and vessels. In this work, we propose a novel DCE-MRI registration framework that can effectively align the DCE-MRI time series. Specifically, our DCE-MRI registration framework consists of two steps, i.e., a de-enhancement synthesis step and a coarse-to-fine registration step. In the de-enhancement synthesis step, a disentanglement network separates DCE-MRI images into a content component representing the anatomical structures and a style component indicating the presence or absence of contrast agents. This step generates synthetic images where the contrast agents are removed from the original images, alleviating the negative effects of intensity changes on the subsequent registration process. In the registration step, we utilize a coarse registration network followed by a refined registration network. These two networks facilitate the estimation of both the coarse and refined displacement vector fields (DVFs) in a pairwise and groupwise registration manner, respectively. In addition, to enhance the alignment accuracy for small structures, a voxel-wise constraint is further conducted by assessing the smoothness of the time-intensity curves (TICs). Experimental results on liver DCE-MRI demonstrate that our proposed method outperforms state-of-the-art approaches, offering more robust and accurate alignment results.

Extreme Precipitation on Consecutive Days Occurs More Often in a Warming Climate

Abstract Extreme precipitation occurring on consecutive days may substantially increase the risk of related impacts, but changes in such events have not been studied at a global scale. Here we use a unique global dataset based on in situ observations and multimodel historical and future simulations to analyze the changes in the frequency of extreme precipitation on consecutive days (EPCD). We further disentangle the relative contributions of variations in precipitation intensity and temporal correlation of extreme precipitation to understand the processes that drive the changes in EPCD. Observations and climate model simulations show that the frequency of EPCD is increasing in most land regions, in particular, in North America, Europe, and the Northern Hemisphere high latitudes. These increases are primarily a consequence of increasing precipitation intensity, but changes in the temporal correlation of extreme precipitation regionally amplify or reduce the effects of intensity changes. Changes are larger in simulations with a stronger warming signal, suggesting that further increases in EPCD are expected for the future under continued climate warming.

Population dynamics and yield of the black goby Gobius niger L. in Algeria (Gulf of Annaba)

Event Abstract Back to Event Population dynamics and yield of the black goby Gobius niger L. in Algeria (Gulf of Annaba) Abderrahmane Kassar1*, Alaeddine Benallia1, Daoud Bouchelif1 and Farid Hemida1 1 École Nationale Supérieure des Sciences de la Mer et de l'Aménagement du Littoral, Algeria The black goby Gobius niger L., 1758 is a demersal gobiid fish caught by bottom trawl in the Gulf of Annaba (South Western Mediterranean). No published prior studies on its biology, population dynamics or stock assessment has been conducted in Algeria. A monthly sampling of this species has been done between Dec 2015 and May 2016 from commercial catch in order to estimate the growth, mortality and exploitation parameters of the stock for the first time in the Algerian Basin. Maximum total length (TL) and maximum total weight (TW) were 15.3 cm and 43.2 g, respectively. Power function type relationship between length and weight was obtained using 344 couples and it was written as TW = 0.0095*TL^3.0701. Estimated von Bertalanffy growth parameters using ELEFAN I routine in FiSAT II program were as follows: L∞ = 16.03 cm and K = 0.8 year-1. The estimated value of Total Mortality based on length converted catch curve was Z = 1.93 year-1. Natural Mortality calculated using Djabali et al. method (1994) based on the asymptotic length and the growth curvature was M = 0.6 year-1. Computed Fishing Mortality was F = 1.33 year-1. The Thompson & Bell model (1934) was used for stock assessment based on data obtained from Jones analysis (1983). Model estimated Maximum Sustainable Yield was MSY = 9 tonnes that corresponds to a 2.6 F-factor. As the reference yield is 8.5 t, there would be scope only to marginally increase the catch by 5.56%. A doubled fishing effort would increase the catch by 7%. Exploitation rate is at its optimum and the applied model recommends maintaining the actual catch. It could also be reduced by a third (loss of 9% of yield), which is more careful in order to protect the stock and preserve the resource in a sustainable way. References Djabali, F., Mehailia, A, Koudil, M., Brahmi B. (1994). A reassessment of equations for predicting natural mortality in Mediterranean teleosts. Naga, the ICLARM Quarterly 17:1, 33-34. Jones, R. (1984). Assessing the effects of changes in exploitation pattern using length composition data (with notes on VPA and cohort analysis). FAO Fisheries Technical Paper 256. Rome: Food and Agriculture Organization of the United Nations. Thompson, W. F., & Bell, F. H. (1934). Effect of changes in intensity upon total yield and yield per unit of gear. Report of the International Fisheries Commission 8, 7-49. Keywords: Algerian basin, Bottom trawling, Gobiidae, Mediterranean Sea, VBGM Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Oral Topic: ECOLOGY AND LIFE CYCLES Citation: Kassar A, Benallia A, Bouchelif D and Hemida F (2019). Population dynamics and yield of the black goby Gobius niger L. in Algeria (Gulf of Annaba). Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00140 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 22 Jul 2019; Published Online: 14 Aug 2019. * Correspondence: Mr. Abderrahmane Kassar, École Nationale Supérieure des Sciences de la Mer et de l'Aménagement du Littoral, Algiers, Algeria, a.w.kassar@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Abderrahmane Kassar Alaeddine Benallia Daoud Bouchelif Farid Hemida Google Abderrahmane Kassar Alaeddine Benallia Daoud Bouchelif Farid Hemida Google Scholar Abderrahmane Kassar Alaeddine Benallia Daoud Bouchelif Farid Hemida PubMed Abderrahmane Kassar Alaeddine Benallia Daoud Bouchelif Farid Hemida Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Cost engineering as the basis for integration of the processes of planning, financing and pricing in investment and construction activity

Current trends in the science and practice of construction indicate the ability to control the economic means of phenomena and processes occurring in the area of investment and construction activities, towards the realization of sustainable development goals. In this regard, the subsystem of planning, funding and pricing implement the problems of resource maintenance of the building complex on the hierarchy levels, the maintenance of homeostatic equilibrium of the system, as well as measure the effectiveness and profitability of production and ensuring processes. The purpose of the article is the search for capability to determine the impact, which are the change in prices for certain types of material and technical resources or reduction of unit costs. Our results are aimed at creating a model for cost control (costs, profit) of an investment and construction project and the development of theoretical foundations of value engineering. Another result of the article is an equation with which you can simulate the effects of intensity changes of individual streams, such as pay increase under certain conditions of construction, changes in the income of an enterprises and other. The features of the article include the recording of the construction hierarchy levels at each time point which depends on the concentration of a certain amount of labor, equipment and the volume of material resources, an optimal distribution between objects and areas of activity, reducing material costs and improving productivity constant. In this case, not only an objective necessity is considered, but also crucial prerequisite for sustainable development. The use of these factors leads to a decrease in the cost of construction of the object as a result of productivity growth and is reflected in the implementation of the final price of construction products.

Radiant heat loss, an unexploited path for heat stress reduction in shaded cattle

Reducing thermal radiation on shaded animals reduces heat stress independently of other means of stress relief. Radiant heat exchange was estimated as a function of climate, shade structure, and animal density. Body surface portion exposed to radiant sources in shaded environments was determined by geometrical relations to determine angles of view of radiation sources (roof underside, sky, sun-exposed ground, shaded ground) on the animal's surface. The relative representation of environment radiation sources on the body surface was determined. Animal thermal radiation balance was derived from radiant heat gained from radiation sources (including surrounding animals) and that lost from the animal surface. The animal environment was assumed to have different shade dimensions and temperatures. These were summed to the radiant heat balance of the cow. The data formed served to estimate the effect of changes in intensity of radiation sources, roof and shaded surface dimensions, and animal density on radiant heat balance (Rbal) of cattle. Roof height effect was expressed by effect of roof temperature on Rbal. Roof underside temperature (35 to 75°C) effect on Rbal was reduced by roof height. If roof height were 4m, an increase in its underside temperature from 35 to 75°C would increase mean Rbal from −63 to −2 W·m−2, whereas if roof height were 10m, Rbal would only increase from −99 to −88 W·m−2. A hot ground temperature increase from 35 to 65°C reduced mean Rbal heat loss from −45 to 3 W·m−2. Increasing the surface of the shaded area had only a minor effect on Rbal and on the effect of hot ground on Rbal. Increasing shade roof height reduced the effect of roof temperature on Rbal to minor levels when height was >8m. Increasing the roof height from 4 to 10m decreased Rbal from −32 to −94 W·m−2. Increasing indirect radiation from 100 to 500 W·m−2 was associated with an increase in Rbal from −135 to +23 W·m−2. Their combined effects were lower Rbal with increasing roof height and a reduction in rate of decrease with increasing level of indirect radiation. Roof height as an Rbal attenuator declined with increasing indirect radiation level. The latter factor might be reduced by lowering roof surface radiation absorption and through roof heat transfer, as well as by use of shade structure elements to reduce indirect radiation in the shaded area. Radiant heat from the cow body surface may be reduced by lower cow density. Radiant heat attenuation may thus further elevate animal productivity in warm climates, with no associated operation costs.

The Effects of Interaural Time Difference and Intensity on the Coding of Low-Frequency Sounds in the Mammalian Midbrain

We examined how changes in intensity and interaural time difference (ITD) influenced the coding of low-frequency sounds in the inferior colliculus of male gerbils at both the single neuron and population levels. We found that changes in intensity along the positive slope of the rate-level function (RLF) evoked changes in spectrotemporal filtering that influenced the overall timing of spike events but preserved their precision across trials such that the decoding of single neuron responses was not affected. In contrast, changes in ITD did not trigger changes in spectrotemporal filtering, but did have strong effects on the precision of spike events and, consequently, on decoder performance. However, changes in ITD had opposing effects in the two brain hemispheres and, thus, canceled out at the population level. These results were similar with and without the addition of background noise. We also found that the effects of changes in intensity along the negative slope of the RLF were different from the effects of changes in intensity along the positive slope in that they evoked changes in both spectrotemporal filtering and in the precision of spike events across trials, as well as in decoder performance. These results demonstrate that, at least at moderate intensities, the auditory system employs different strategies at the single neuron and population levels simultaneously to ensure that the coding of sounds is robust to changes in other stimulus features.

Hard work impinges on fitness: an experimental study with zebra finches

In experiments in which brood size is manipulated, it is impossible to disentangle the effects of changes in intensity and duration of parental care on parental fitness from those of changes in the parental energy budget. To determine whether a change in parental energy budget affects the costs of reproduction, we assessed the effects of increased levels of hopping activity, independent of parental care, on later reproductive decisions in zebra finches, Taeniopygia guttata . We imposed two levels of workload on individual, nonbreeding birds. After the workload periods, the birds were allowed to breed in ad libitum conditions. Each bird went through three alternating periods of working followed by breeding. The birds were more active, but weighed less and ate less, during the high workload than during the low workload periods. Clutch sizes and brood sizes did not vary with the previous work level. However, after a period on the high workload, reproduction, on average, was started 6 days later than after a low workload period. Females gained weight just before egg laying, but this might have been a result of egg production. If so, the delay in reproduction did not simply reflect extra time needed to restore body mass after a period of increased activity. We conclude that the level of daily activity itself, or the resulting energy budget during the workload periods, delayed reproduction. We suggest that these observations on the effects of increased activity demonstrate a causal mechanism for reduced residual fitness of parents.

Binaural interaction in high-frequency neurons in inferior colliculus of the cat: effects of variations in sound pressure level on sensitivity to interaural intensity differences

1. Development of models of the manner in which interaural intensity differences (IIDs), the major binaural cue for the azimuthal location of high-frequency sounds, are coded by populations of neurons requires knowledge of the extent to which the IID sensitivity of individual neurons is invariant with changes in sound pressure level (SPL) and other stimulus parameters. To examine this tissue, recordings were obtained from a large sample (n = 458) of neurons with characteristic frequency (CF) greater than 3 kHz in the central nucleus of the inferior colliculus (ICC) of anesthetized cats. The sensitivity to IIDs and the effects of changes in SPL on this sensitivity were examined in neurons receiving excitatory contralateral input and inhibitory or mixed inhibitory/facilitatory ipsilateral input (EI neurons). 2. The form of an EI neuron's IID sensitivity and the effects of changes in SPL on that sensitivity were found to be determined in part by the characteristics of the neuron's rate-intensity function for monaural contralateral stimulation, and detailed rate-intensity functions were therefore obtained for 91 neurons. Many ICC neurons have nonmonotonic rate-intensity functions, the proportion so classified depending on the criterion of nonmonotonicity employed. 3. IID sensitivity functions for CF tonal stimuli were obtained at one or more intensities for 90 neurons, using a method of generating IIDs that kept the average binaural intensity (ABI) of the stimuli at the two ears constant. In the standard ABI range in which a function was obtained for each unit, the majority of EI neurons (72%) had monotonic (sigmoidal) or near-monotonic IID sensitivity functions. The remainder had nonmonotonic (peaked) IID sensitivity functions, which were attributable either to mixed inhibitory and facilitatory ipsilateral influences or to the fact that the effects of ipsilateral stimulation were superimposed on nonmonotonic effects of changes in intensity at the excitatory ear. 4. IID sensitivity was examined at two or more ABIs (3-5 in most cases) for 40 neurons classified as having monotonic or near-monotonic functions in the standard ABI range and for 7 neurons classified as nonmonotonic. For a small proportion of neurons with monotonic IID sensitivity functions, the form of the function was relatively invariant with changes in ABI. In those monotonic neurons in which the form of the IID sensitivity function varied with changes in ABI, the most common type of variation was that the position of the sloping portion of the function shifted systematically in the direction of larger IIDs favoring the ipsilateral ear as ABI increased.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of intensity and duration of light on photorefractoriness and subsequent egg production of chukar partridge.

Three photoperiodic experiments on egg production of chukar partridge (Alectoris graeca chukar) were conducted under controlled ‘environmental conditions. In test 1 the photorefractoriness of blind, thyroidectomized and intact chukars to long days (LD16:8) was examined from hatch until 123 weeks of age. Thereafter, the effects of long days of low intensity light (4 lux) on terminating the refractory period were observed. In the second test, the minimum level of light intensity to induce egg laying in chukars was determined at 64 and 103 weeks of age. In addition, the effect of step-wise increases in light intensity on egg production and photorefractoriness was compared to steady levels of light intensity. In the third test, 2 consecutive egg laying cycles were induced in blinded and intact chukars. Again the threshold level of light intensity to induce egg laying was determined. In addition, the effects of larger changes in intensity (lOX) in terminating photorefractoriness were determined. The results indicate the following: 1) neither blinding nor thyroidectomy alters photorefractoriness; 2) either exposure to short daylengths or to low light intensity is necessary to break photorefractoriness before chukars can be photostimulated into egg production by long days; 3) the minimum light intensity for egg production is 2 lu.x; 4) chukars possess extraretinal photoreceptor(s) which respond to changes in both day length and intensity; 5) small changes in light intensity (2-5X) have little effect in terminating photorefractoriness; 6) lox changes in intensity suppress photorefractoriness and allows an increase in both the duration of lay and the number of eggs.

The directional effect of intensity change on estimative differences in loudness

Abstract Two experiments are reported which seek to test the hypothesis that there would be a greater perceived difference in intensity of two tones presented in an increasing order of intensity than the same tones presented in a decreasing order. In Experiment I, 41 subjects indicated which of a two-tone set, in successive three-tone trials, contained the greater intensity difference. In Experiment II, 18 subjects numerically estimated the intensity difference of two tones presented in both orders of intensity change. The results of both experiments support the hypothesis. These results are discussed in reference to orientation response (OR) research.

The Problems of Vision in Flight at High Altitude

Abstract : Contents: Effects of changes in intensity and spectral distribution of sunlight at high altitude; Physiological changes affecting visibility of objects inside the cockpit; Physiological factors affecting air-to-air visibility.

A New Species of Carangid Fish from the Northeastern Pacific

LITERATURE CITED BARANOFF, TH. I. 1918 On the question of the biological basis of fisheries. Nauchnyi issledovatelskii iktiologisheskii Institut, Izvestiia, 1 (1), (1916): 81-128. (In Russian.) GRAHAM, MICHAEL 1935 Modern theory of exploiting a fishery, and application to North Sea trawling. Journ. Conseil Explor. Mer, 10: 264-74. 1938 Rates of fishing and natural mortality from the data of marking experiments. Ibid., 13: 76-90. PETERSEN, C. G. J. 1922 On the stock of plaice and the plaice fisheries in different waters. Rept. Danish Biol. Sta., 29: 1-43. RICKER, W. E. 1940 Relation of catch per unit to abundance and rate of exploitation. Journ. Fish. Res. Bd. Canada, 5 (1): 43-70. SCHAEFER, M.B. 1943 The theoretical relationship between fishing effort and mortality. COPEIA, 1943: 79-82. THOMPSON, W. F., and F. H. BELL 1934 Biological statistics of the Pacific halibut fishery. (2) The effect of changes in intensity upon total yield and yield per unit of gear. Rept. Intern. Fish Comm., 8: 49 pp.

Photographic sensitivity and the reciprocity law at low temperatures

The experiments described below were undertaken in order to examine a theory by Gurney and Mott (1938) on the formation of the latent image. The theory adopts the old conception, that the latent image consists of a speck of silver, which is produced from the silver halide by a two-stage process. The first stage consists in the lifting of an electron from a bromine ion into the conductivity band in which the electron moves until it is trapped by a region of low potential, the “sensitivity speck”. The second stage consists in the movement of the positive silver ions up to the charged sensitivity speck. The ionic movement should depend on temperature as e - E/kT and one should therefore expect the sensitivity of photographic materials almost to disappear at sufficiently low temperatures. Experiments at liquid air temperature have been made by several investigators (see, for instance, Sheppard, Wightman, and Quirk 1934). The sensitivity found is of the order of 5‒10 % of room temperature sensitivity and appears surprisingly high in view of the above considerations. It seemed desirable to lower the temperature still further by using liquid hydrogen and to test in particular for the effect of change in intensity and time, while keeping the exposure, i. e. The product of intensity with time, constant. A great amount of work has been done on the reciprocity failure of sensitive materials, by which is meant the fact that for a constant exposure the density obtained after processing depends on the intensity level at which the exposure was given. (Webb 1933 a , b ; Jones and Webb 1934). It appears that for every material there is an optimum rate of reception of energy. The position of the optimum depends on temperature (Webb 1935), and for this reason alone the investigation of the reciprocity failure at as low a temperature possible seemed desirable. It was hoped that some information on the mechanism of the latent image formation could be obtained in this way.