Approximate Magnitude Research Articles

Neurons in the Dorso-Central Division of Zebrafish Pallium Respond to Change in Visual Numerosity.

We found a region of the zebrafish pallium that shows selective activation upon change in the numerosity of visual stimuli. Zebrafish were habituated to sets of small dots that changed in individual size, position, and density, while maintaining their numerousness and overall surface. During dishabituation tests, zebrafish faced a change in number (with the same overall surface), in shape (with the same overall surface and number), or in size (with the same shape and number) of the dots, whereas, in a control group, zebrafish faced the same stimuli as during the habituation. Modulation of the expression of the immediate early genes c-fos and egr-1 and in situ hybridization revealed a selective activation of the caudal part of the dorso-central division of the zebrafish pallium upon change in numerosity. These findings support the existence of an evolutionarily conserved mechanism for approximate magnitude and provide an avenue for understanding its underlying molecular correlates.

Characterization of Surface Geology and Hydrogeology in the Upper Ulua River Basin, Honduras

This research includes a hydrogeologic assessment in and around La Union, Honduras to determine the contribution of groundwater to the surface water system and understand the geological control of groundwater storage and movement. Field methods were employed and focused on spring characterization, geochemical signatures, and structural data. Field data was gathered, and locations determined using cellular-integrated GPS signal and the Fulcrum mapping software mobile application. During the summer of 2017, data on 111 geologic points and 34 water points were collected to understand the hydrogeology of the region. Streams and springs were monitored for pH, flow characteristics and conductance as a measure of total-dissolved-solids (TDS). TDS ranged from 22.6 to 485 mg/L with higher values indicating groundwater influx into the surface system. In comparison, lower TDS values are attributed to runoff. Structural information was collected using a Brunton transit compass for strike and dip of lithologic contacts. Structural trends include strikes around 240 degrees, dip direction and approximate magnitudes at 330 and 40 degrees, respectively. Geologic data indicate significant structural deformation, supportive of tectonic activity in the region. For many of the springs in this area, the data can be used to interpret that water is stored in the Jaitique Formation as a perched aquifer controlled by stratigraphy and structure. The groundwater moves down dip through secondary porosity in the Jaitique Formation until it comes into contact with the Lower Valle de Angeles. This Lower Valle de Angeles unit acts as an aquiclude preventing percolation into the ground and resulting in springs at the surface.

Cancer Progress and Priorities: Breast Cancer.

Breast cancer is the most commonly diagnosed invasive cancer among women both globally and within the United States and the number one cause of cancer-related deaths among women globally ([1, 2][1]). Less than 1% of diagnosed breast cancers occur in men ([2][2]) and, therefore, male breast cancer is

Neurodevelopmental differences in child and adult number processing: An fMRI-based validation of the triple code model

The triple code model of numerical cognition (TCM) details the neurocognitive mechanisms associated with perceiving and manipulating numerical information in exact symbolic (Arabic digits and number words) and approximate nonsymbolic numerical magnitude (e.g., dot arrays) representation codes. The current study provides a first empirical fMRI-based investigation into neurodevelopmental differences in 30 healthy children’s and 44 healthy adults’ recruitment of neural correlates associated with the Arabic digit, number word, and nonsymbolic magnitude codes. Differences between the two groups were found in cingulate regions commonly associated with domain-general aspects of cognitive control, as opposed to neural correlates of number processing per se. A primary developmental difference was identified in verbal number discrimination, where only adults recruited left-lateralized perisylvian language areas in accordance with the TCM. We therefore call for a revision of the verbal code and a formulation of separate child and adult-specific neurocognitive mechanisms associated with the discrimination of number words. Although further research is necessary, results indicate that numerical discrimination abilities in middle-school-aged children operate close to adult-level maturity. Neurodevelopmental differences may be more apparent in younger children, or on the level of functional network dynamics as opposed to a shift in recruited neural substrates.

Chapter 6.1 Marine record of Antarctic volcanism from drill cores

Abstract We review here data and information on Antarctic volcanism resulting from recent tephrostratigraphic investigations on marine cores. Records include deep drill cores recovered during oceanographic expeditions: DSDP, ODP and IODP drill cores recovered during ice-based and land-based international cooperative drilling programmes DVDP 15, MSSTS-1, CIROS-1 and CIROS-2, DVDP 15, CRP-1, CRP-2/2A and CRP-3, ANDRILL-MIS and ANDRILL-SMS, and shallow gravity and piston cores recovered in the Antarctic and sub-Antarctic oceans. We report on the identification of visible volcaniclastic horizons and, in particular, of primary tephra within the marine sequences. Where available, the results of analyses carried out on these products are presented. The volcanic material identified differs in its nature, composition and emplacement mechanisms. It was derived from different sources on the Antarctic continent and was emplaced over a wide time span. Marine sediments contain a more complete record of the explosive activity from Antarctic volcanoes and are complementary to those obtained by land-based studies. This record provides important information for volcanological reconstructions including approximate intensities and magnitudes of eruptions, and their duration, age and recurrence, as well as their eruptive dynamics. In addition, characterized tephra layers represent an invaluable chronological tool essential in establishing correlations between different archives and in synchronizing climate records.

Constructing rationals through conjoint measurement of numerator and denominator as approximate integer magnitudes in tradeoff relations.

To investigate mechanisms of rational representation, I consider (1) construction of an ordered continuum of psychophysical scale of magnitude of sensation; (2) counting mechanism leading to an approximate numerosity scale for integers; and (3) conjoint measurement structure pitting the denominator against the numerator in tradeoff positions. Number sense of resulting rationals is neither intuitive nor expedient in their manipulation.

Temporal properties of aftershock sequences of large earthquakes in Iran - Analysis of primary and secondary aftershocks of the Ezgeleh sequence

In this study, the decay of earthquake aftershock sequences of some major earthquakes in different tectonic regimes in the Iranian plateau is discussed. The studied earthquakes are Rigan [2010], Ahar-Varzaghan [2012], Goharan [2013], Sefidsang [2017] and Ezgeleh [2017]. The spatial and temporal windows are considered based on the method proposed by Gardner and Knopoff [1974] to compute decay parameters for each sequence. The decay rates of sequences were compared to well-known models to find the best fit for each sequence. The results showed that the modified Omori is the best fit for Ahar-Varzaghan and Ezgeleh sequences, for Rigan and Sefidsang sequences the modified Omori and the Kisslinger ones found as the best fits. The values of the p parameter of the Reasenberg and Shcherbakov models were larger compared to the Omori model, but the parameter of the Kisslinger model was slightly smaller compared to the Omori one. The c parameter showed an inverse relation to the threshold magnitude. The correlation between the p and c parameters and also the and the Gutenberg and Richter (G-R) parameters were investigated. In addition, we made use of a graphical method to analyze the seismic sequence of the Ezgeleh earthquake during 13 months after the main event. The graphical method was successful to estimate the occurrence of an event with an approximate magnitude of M=6.4 in the sequence.

An Internuclear J-Coupling of 3He Induced by Molecular Confinement.

The solution-state 13C NMR spectrum of the endofullerene 3He@C60 displays a doublet structure due to a J-coupling of magnitude 77.5 ± 0.2 mHz at 340 K between the 3He nucleus and a 13C nucleus of the enclosing carbon surface. The J-coupling increases in magnitude with increasing temperature. Quantum chemistry calculations successfully predict the approximate magnitude of the coupling. This observation shows that the mutual proximity of molecular or atomic species is sufficient to induce a finite scalar nuclear spin-spin coupling, providing that translational motion is restricted by confinement. The phenomenon may have applications to the study of surface interactions and to mechanically bound species.

Critical condition relevant to the extinction of a carbon particle in the course of combustion

In order to examine extinction of carbon particle in the course of combustion, an attempt has been made to obtain its critical condition. Main concern has been put on the particle extinction in the lower limit that can occur at the end of the particle combustion although not only the lower limit but also the upper limit of the critical conditions has been obtained. By conducting asymptotics, with focusing on the temporal variation of the particle temperature, an analytical expression has been obtained for the limit of the particle diameter, as functions of the pressure ratio, oxygen mass-fraction, ambient temperature, and/or radiative heat flux. An approximate expression is also obtained from the analytical solution. It is found that the approximate expression can fairly represent the limits. In addition, use has been made of the Arrhenius plot of a comprehensive parameter, consisting of the particle diameter and pressure ratio, in order to identify regions for the particle combustion sustained, which are next to those for the particle extinction. Comparisons have also been conducted by use of experimental data in the literature, with presenting a fair degree of agreement, as far as the trend and approximate magnitude are concerned. It has been confirmed that the formulation has captured the essential feature, that the reduction in particle size does not necessarily favor the particle combustion, and that the particle extinction can occur when the particle diameter is reduced to the critical value.

Modeling spurious forces on the LISA spacecraft across a full solar cycle

One source of noise for the laser interferometer space antenna (LISA) will be time-varying changes of the space environment in the form of solar wind particles and photon pressure from fluctuating solar irradiance. The approximate magnitude of these effects can be estimated from the average properties of the solar wind and the solar irradiance. We use data taken by the ACE (advanced Compton explorer) satellite and the VIRGO (variability of solar iRradiance and gravity oscillations) instrument on the SOHO satellite over an entire solar cycle to calculate the forces due to solar wind and photon pressure irradiance on the LISA spacecraft. We produce a realistic model of the effects of these environmental noise sources and their variation over the expected course of the LISA mission.

Simulation of Northeast U.S. Extreme Precipitation and Its Associated Circulation by CMIP5 Models

AbstractHistorical simulations from 14 models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) are evaluated for their ability to reproduce observed precipitation in the northeastern United States and its associated circulation, with particular emphasis on extreme (top 1%) precipitation. The models are compared to observations in terms of the spatial variations of extreme precipitation, seasonal cycles of precipitation and extreme precipitation frequency and intensity, and extreme precipitation circulation regimes. The circulation regimes are identified using k-means clustering of 500-hPa geopotential heights on extreme precipitation days, in both observations and in the models. While all models capture an observed northwest-to-southeast gradient of precipitation intensity (reflected in the top 1% threshold), there are substantial differences from observations in the magnitude of the gradient. These differences tend to be more substantial for lower-resolution models. However, regardless of resolution, and despite a bias toward too-frequent precipitation, many of the models capture the seasonality of observed daily precipitation intensity, and the approximate magnitude and seasonality of observed extreme precipitation intensity. Many of the simulated extreme precipitation circulation patterns are visually similar to the set of observed patterns. However, the location and magnitude of specific troughs and ridges within the patterns, as well as the seasonality of the patterns, may differ substantially from the observed corresponding patterns. A series of metrics is developed based on the observed regional characteristics to facilitate comparison between models.

SH-waveform modeling of small local seismic events in Ladoga lake

A lot of seismic phenomena with small magnitude has been taking place in the Ladoga lake region (northwestern Russia). One of them is the earthquake which was recorded on the 31st of July, 2010 followed by the swarm of microearthquakes near Nikonovsky cape. There is only one station in the region that is why it is difficult to process the data. In this work, we propose a new approach to construct synthetic seismograms of the main event with minimum data. Also this approach applies us to calculate parameters of the source. The approximate magnitude of the main event is $$M_L=-0.8$$ . For swarm events, we have magnitude values from $$-\,1.0$$ to $$-\,2.6$$ . The data of swarm events (microearthquakes) is used to test the technique of constructing synthetic seismograms. The approach we propose is based on Green’s function method with using two temporal $$\delta$$ -sequences (the Lorentzian function and the continuous Dirichlet kernel). A comparison of synthetic and real seismograms shows that the Lorentzian function is better to describe small local events, and the continuous Dirichlet kernel is more appropriate for earthquakes. This approach can be generalized to various problems of different nature.

Fuzzy prediction and pattern analysis of poultry egg production

Egg production is geared towards large scale production of eggs for profit maximization and consumption. But poultry farmers are faced with challenges that affect the quantity and quality of egg production during the production life cycle such as quality of feed intake, management issues, genetic factors of the breed birds, age at egg laying period, presence of diseases, molting flock, housing and others. Several mechanical solutions have been suggested to implement the production cycle but with very high cost implication which calls for the need of soft computing methods to model the egg production process. However, modelling egg production curve is a complex task because a typical egg production curve (from week 20 to week 72) is characterized by nonlinear probabilities and imprecise knowledge in the egg production process. This paper proposes an optimal fuzzy predictive model for poultry egg production. The motivation stems from analyzing the non-linearity and imprecision in egg production which is best handled by fuzzy logic as compared to other soft computing techniques. Data samples were collected on the age of chicks, quantity of feeds, quality of feeds, body weight of chicks and total egg production as input into the proposed system. The first stage of implementation is carried out in the Statistical Package for Social Science (SPSS) software environment to perform correlation analysis while the last two stages are carried out using Fuzzy Toolbox in MATLAB based on its capability to model and simulate complex systems with robust and interpretable predictions. Gaussian membership function was used in the fuzzification process while Mamdami structure was adopted as the fuzzy inference system (FIS). Model performance evaluation showed that the proposed system performed excellently by achieving best prediction accuracy 100% Pred(30) with an approximate mean magnitude relative error (MMRE) of 0.11744 as compared to the results in the reported literature. The method has proven to be a cost-effective and simple approach to modelling through the use of samples and parameters from poultry house.

Characterizing the Uncertainty in Cluster Magnetic Fields Derived from Rotation Measures

Abstract Magnetic fields play vital roles in intracluster media (ICMs), but estimating their strengths and distributions from observations is a major challenge. Faraday rotation measures (RMs) are widely applied to this task, so it is critical to understand inherent uncertainties in RM analysis. In this paper, we seek to characterize those uncertainties given the types of information available today, independent of the specific technique used. We conduct synthetic RM observations through the ICM of a galaxy cluster drawn from a magnetohydrodynamic cosmological simulation in which the magnetic field is known. We analyze the synthetic RM observations using an analytical formalism based on commonly used model assumptions, allowing us to relate model physical variables to outcome uncertainties. Despite the simplicity of some assumptions, and unknown physical parameters, we are able to extract an approximate magnitude of the central magnetic field within an apparently irreducible uncertain factor of ≈3. Principal, largely irreducible, uncertainties come from the unknown depth along the line of sight of embedded polarized sources, the lack of robust coherence lengths from area-constrained polarization sampling, and the unknown scaling between ICM electron density and magnetic field strength. The RM-estimated central magnetic field strengths span more than an order of magnitude including the full range of synthetic experiments.

A comes before B, like 1 comes before 2. Is the parietal cortex sensitive to ordinal relationships in both numbers and letters? An fMRI-adaptation study.

How are number symbols (e.g., Arabic digits) represented in the brain? Functional resonance imaging adaptation (fMRI‐A) research has indicated that the intraparietal sulcus (IPS) exhibits a decrease in activation with the repeated presentation of the same number, that is followed by a rebound effect with the presentation of a new number. This rebound effect is modulated by the numerical ratio or difference between presented numbers. It has been suggested that this ratio‐dependent rebound effect is reflective of a link between the symbolic numerical representation system and an approximate magnitude system. Experiment 1 used fMRI‐A to investigate an alternative hypothesis: that the rebound effect observed in the IPS is related to the ordinal relationships between symbols (e.g., 3 comes before 4; C after B). In Experiment 1, adult participants exhibited the predicted distance‐dependent parametric rebound effect bilaterally in the IPS for number symbols during a number adaptation task, however, the same effect was not found anywhere in the brain in response to letters. When numbers were contrasted with letters (numbers > letters), the left intraparietal lobule remained significant. Experiment 2 demonstrated that letter stimuli used in Experiment 1 generated a behavioral distance effect during an active ordinality task, despite the lack of a neural distance effect using fMRI‐A. The current study does not support the hypothesis that general ordinal mechanisms underpin the neural parametric recovery effect in the IPS in response to number symbols. Additional research is needed to further our understanding of mechanisms underlying symbolic numerical representation in the brain.

The Macaque Cerebellar Flocculus Outputs a Forward Model of Eye Movement.

The central nervous system (CNS) achieves fine motor control by generating predictions of the consequences of the motor command, often called forward models of the movement. These predictions are used centrally to detect not-self generated sensations, to modify ongoing movements, and to induce motor learning. However, finding a neuronal correlate of forward models has proven difficult. In the oculomotor system, we can identify neuronal correlates of forward models vs. neuronal correlates of motor commands by examining neuronal responses during smooth pursuit at eccentric eye positions. During pursuit, torsional eye movement information is not present in the motor command, but it is generated by the mechanic of the orbit. Importantly, the directionality and approximate magnitude of torsional eye movement follow the half angle rule. We use this rule to investigate the role of the cerebellar flocculus complex (FL, flocculus and ventral paraflocculus) in the generation of forward models of the eye. We found that mossy fibers (input elements to the FL) did not change their response to pursuit with eccentricity. Thus, they do not carry torsional eye movement information. However, vertical Purkinje cells (PCs; output elements of the FL) showed a preference for counter-clockwise (CCW) eye velocity [corresponding to extorsion (outward rotation) of the ipsilateral eye]. We hypothesize that FL computes an estimate of torsional eye movement since torsion is present in PCs but not in mossy fibers. Overall, our results add to those of other laboratories in supporting the existence in the CNS of a predictive signal constructed from motor command information.

A study of Socio-demographic factors and fertility in a village of Western Maharashtra

Background: In India rural population was reported to be 66%.there is gap in fertility of rural and urban population.Worldwide, fertility rates have fallen from an average of about six children per woman in the 1950s to fewer than threetoday. Total fertility rate (TFR) gives approximate magnitude of the completed family size. Objectives: To describe sociodemographicfactors and ascertaining relationship of fertility with socio-demographic factors in a rural area of Maharashtra.Results: A total 292 families were interviewed from Dahitane village; Majority Head of family were Hindu males (90%).About 93% population resided in their own houses in that 63% houses were semi-pucca. Houses having electricity supply, inhouse water connection and in-house latrines were 91%, 39% and 61% respectively. Total fertility rate (TFR) was found tobe 1.71 and not significantly associated with socioeconomic class and female literacy. Conclusions: The present studyshowed betterment in water supply and sanitation facility in rural dwellings in spite of the predominance of semi-puccahouse.

Revealing the Source of the 27 August 1810 Loreto, Baja California, Tsunami from Historical Evidence and Numerical Modelling

Historical documents revealed that on 27 August 1810 an earthquake affected the Loreto town and the surrounding region, along 200 km of the coast of Baja California, Mexico, and damage was considerable due to strong ground motions. However, the 1810 Loreto earthquake, unlike other earthquakes of the nineteenth and twentieth centuries, produced an extensive tsunami flooding on the eastern coast of Baja California, from Loreto to La Paz. We report here the historical account of this event and analyse the source of the related tsunami. Based on the historical record and the tectonic setting, we infer that this earthquake was produced along a transform fault, right-lateral strike slip fault, Farallon fault, on the Baja California Gulf. However, the associated tsunami was disproportionally large if compared with the earthquake intensity (IX) and approximate magnitude (7.4 Mw), fault style, and the relatively late tsunami arrival, i.e. an hour after the earthquake, suggesting that a submarine landslide, triggered by this earthquake, was the suspect source for the Loreto tsunami. We present here historical data and a numerical model of the Loreto 1810 tsunami to elucidate the source, using both the 1810 earthquake and a submarine landslide, and confirm that a submarine landslide is most likely the tsunami-triggering mechanism that followed the 1810 earthquake.

Seasonality and community interventions in a mathematical model of Clostridium difficile transmission

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhoea with peak incidence in late winter or early autumn. Although CDI is commonly associated with hospitals, community transmission is important. To explore potential drivers of CDI seasonality and the effect of community-based interventions to reduce transmission. A mechanistic compartmental model of C.difficile transmission in a hospital and surrounding community was used to determine the effect of reducing transmission or antibiotic prescriptions in these settings. The model was extended to allow for seasonal antibiotic prescriptions and seasonal transmission. Modelling antibiotic seasonality reproduced the seasonality of CDI, including approximate magnitude (13.9-15.1% above annual mean) and timing of peaks (0.7-1.0 months after peak antibiotics). Halving seasonal excess prescriptions reduced the incidence of CDI by 6-18%. Seasonal transmission produced larger seasonal peaks in the prevalence of community colonization (14.8-22.1% above mean) than seasonal antibiotic prescriptions (0.2-1.7% above mean). Reducing transmission from symptomatic or hospitalized patients had little effect on community-acquired CDI, but reducing transmission in the community by ≥7% or transmission from infants by ≥30% eliminated the pathogen. Reducing antibiotic prescription rates led to approximately proportional reductions in infections, but limited reductions in the prevalence of colonization. Seasonal variation in antibiotic prescription rates can account for the observed magnitude and timing of C.difficile seasonality. Even complete prevention of transmission from hospitalized patients or symptomatic patients cannot eliminate the pathogen, but interventions to reduce transmission from community residents or infants could have a large impact on both hospital- and community-acquired infections.

Evaluating alternative methods of asset pricing based on the overall magnitude of pricing errors

We are the first pioneers who evaluate the overall fitness of the two-pass Fama–MacBeth regression and the generalized method of moments (GMM) by comparing the R2 or mean absolute pricing error (MAE), using a Monte Carlo simulation of different models and portfolios for hundreds of trials and, in particular, focusing on the case that the expected return is always a gross return in both methods. Our findings reveal an innovative finding that both methodologies achieve approximate overall magnitudes of pricing errors.