Random Counts Research Articles

Wasserstein-2 bounds in normal approximation under local dependence

We obtain a general bound for the Wasserstein-2 distance in normal approximation for sums of locally dependent random variables. The proof is based on an asymptotic expansion for expectations of second-order differentiable functions of the sum. We apply the main result to obtain Wasserstein-2 bounds in normal approximation for sums of $m$-dependent random variables, U-statistics and subgraph counts in the Erd\H{o}s-R\'enyi random graph. We state a conjecture on Wasserstein-$p$ bounds for any positive integer $p$ and provide supporting arguments for the conjecture.

Fertility preservation in women with malignancies: the accuracy of antral follicle count collected randomly during the menstrual cycle in predicting the number of oocytes retrieved.

To evaluate the capacity of random antral follicle count (AFC), i.e., AFC recorded at any time during the menstrual cycle, to predict the number of retrieved mature oocytes in women with malignancies undergoing random start ovarian hyperstimulation METHODS: A consecutive series of 72 women with malignancies who underwent ovarian hyperstimulation aimed at egg freezing between July 2014 and December 2016 was retrospectively reviewed. A standardized random start protocol was used for all women. AFC and serum AMH were systematically assessed prior to initiating ovarian hyperstimulation. The main outcome was the retrieval of ≥ 10 mature oocytes. The accuracy of random AFC was tested with the c-statistics (area under the ROC curve). For the whole cohort, the c-statistics for the prediction of ≥ 10 mature oocytes using AFC and serum AMH were similar. Specifically, the areas under the curve were 0.76 (95%CI 0.66-0.87) and 0.82 (95%CI 0.72-0.92), respectively (p = ns). Moreover, when considering the subgroup of women recruited after day 5 of the cycle (proper random start, n = 52), the areas under the curve did not also differ. Specifically, they resulted in 0.77 (95%CI 0.64-0.89) and 0.83 (95%CI 0.72-0.95), respectively (p = ns). AFC collected at any time during the menstrual cycle can provide valuable information for the counseling of women with malignancies scheduled for oocyte cryopreservation. Its reliability appears to be non-inferior to that of serum AMH.

Effect of Supra-Physiological Doses of Anabolic-Androgenic Steroids on the Neuronal Density of the Central and Basolateral Amygdala in Mice

Anabolic-androgenic steroids (AAS), despite being controlled by government agencies, are illegally marketed and heavily consumed among youngsters that want a lean, muscular appearance and improved physical performance. Behavioral changes mediated by the amygdala, such as depression, aggressiveness and anxiety, are reported among users. The main scope of this work is to quantify the number of neuron cells on the nuclei of the central (CA) and basolateral (BLA) mice's amygdala submitted to a chronic supra-physiological doses of Durateston® (a combination of testosterone propionate, testosterone isocaproate and testosterone decanoate) and Deca Durabolin® (nandrolone decanoate), administered isolated and combined. For this purpose, 40 Swiss male mice were taken and divided into 4 (four) groups (n = 10): a control group (C), in which mice received saline solution; a Dura group, in which mice received Durateston®; a Deca group, in which mice received Deca Durabolin®; and a Dura-Deca group, in which mice received both drugs. Mice were treated with AAS for a period of 60 days and underwent exercises (swimming). After this time, mice were euthanized and had their brains removed. The material thus obtained was processed in a conventional histological routine. For the neuron cells quantitative analyses, the simple random sampling count method was used. The results showed that there was a significant decrease in the number of neuron cells in all AAS treated animals comparing to the control group; concerning the amygdala basolateral nucleus, the decrease ranged from 23% to 36%, according to the AAS selected group; regarding the amygdala central nucleus, the decrease ranged from 20% to 29%, according to the AAS selected group. One can conclude that the administration of supra-physiological doses of these AAS causes decrease in the number of neuron cells on the central and basolateral nuclei of Swiss male mice's amygdala.

An Investigation of the Safety Performance of Roundabouts in Korea Based on a Random Parameters Count Model

It is well known that a roundabout is an efficient and safe intersection. However, the safety is generally influenced by the given various conditions. This study analyzed the effects of the geometric and traffic flow conditions on traffic accident frequency at roundabouts, constructed in Korea since 2010. Many previous studies have investigated the efficiency and safety effects of roundabout installation. However, not many studies have analyzed the specific influences of individual geometric elements and traffic flow conditions of roundabouts. Accordingly, this study analyzed the effects of various influencing variables on traffic accident frequency based on a random parameter count model using traffic accident data in 199 roundabouts. Using random parameters that can take into account unobserved heterogeneity, this study tried to make up for the weakness of the fixed parameters model, which constrains estimated parameters to be fixed across all observations. A total of eight variables were determined to be the main influencing factors on traffic accident frequency including the number and width of entry lanes, the presence of pedestrian crossings, the width of the circulatory lanes, the presence of central islands, the radius and number of entry lanes, and traffic volume influence accident frequency. Based on the study results, safer roundabout design and more efficient roundabout operation are expected.

Hemispheric decoupling of awareness-related activity in human auditory cortex under informational masking and divided attention

Whether unattended sound streams reach perceptual awareness, and the extent to which they are represented in the central auditory system, are fundamental questions of modern hearing science. We examined these questions utilizing M/EEG, multi-tone masking, and a dual-task dichotic listening paradigm. Listeners performed a demanding primary task in one ear—detecting isochronous target-tone streams embedded in random multi-tone backgrounds and counting within-target-stream deviants—and retrospectively reported their awareness of similar masker-embedded targets in the other ear. Irrespective of attention or stimulation ear, left-AC activity strongly covaried with target-stream detection starting as early as 50 ms post-stimulus. In contrast, right-AC activity, while highly sensitive to stimulation ear, was unmodulated by detection until later, and then only weakly. Thus, under certain conditions, human ACs can functionally decouple, such that one—here, right—is automatic and stimulus-driven while the other—here, left—supports perceptual and/or task demands, including basic perceptual awareness of nonverbal sounds both within and outside the focus of top-down selective attention.

Estimating Lost Recreational Use Values of Visitors to Northwest Florida due to the Deepwater Horizon Oil Spill Using Cancelled Trip Data

AbstractThe lost recreational use values from the BP/Deepwater Horizon oil spill in the Gulf of Mexico were estimated from cancelled recreational trips to Northwest Florida. The impacts were calculated using the travel cost method for a single site with primary data collected from an online survey conducted after the spill. The data were collected in August and September 2011 with respondents residing in 13 US states that constitute the primary domestic market for coastal tourism to Northwest Florida. The survey gathered information from respondents on their recreational visits, including detailed information on their past trips and the number of trips cancelled to the study region due to the oil spill. The empirical analysis involves the estimation of a random parameter negative binomial count data demand model. Using this model we find significant preference heterogeneity surrounding the effects of the oil spill. Aggregate damages are estimated to be $207 million.

A multivariate heterogeneous-dispersion count model for asymmetric interdependent freeway crash types

A multivariate count model is developed by introducing a simple and practical formula. The formulation begins with a modification of the standard ordered response model to adopt the count outcomes nature. This modification is accomplished by introducing a non-linear asymmetric interdependence structure among the error terms using the copula-based model. To avoid simulation maximum-likelihood for evaluating the multi-outcome density, we utilize the composite marginal likelihood (CML) approach. The proposed copula-based model with the CML approach allows for asymmetric (tail) dependency without a need for a simulation mechanism. Non-parametric graphical techniques with the empirical copula as well as conventional goodness-of-fit statistics are utilized to guide copula selection. In addition, unobserved heterogeneity across observations is also addressed through a heterogeneous dispersion parameter in the proposed model. The heterogeneous dispersion parameter model is a suitable alternative to random parameter count models in that captures heterogeneity in variance, while allowing for closed form while the latter needs numerical integration or simulation.We apply these techniques to study the interdependence structure among four types of traffic crashes using three years (2005–2007) of cross-sectional crash data record for 274 multilane freeway segments in the State of Washington, USA. These four categories of crash types are the rear end; sideswipe; fixed objects and other crash types. The empirical results show a significant presence of unobserved heterogeneous dependency across these types of crashes. The results indicate the important role of unobserved heterogeneity in variance and covariance structure estimation. An important outcome of this result is that it can affect inference on the relative impact of roadway geometrics on crash occurrence. For example, we find that horizontal curve related parameters on freeway segments substantially increase the joint likelihood of rear-end, sideswipe, fixed objects and other crash types, when compared to the characteristics of vertical curves.

Counter-Based Broadcast Scheme Considering Reachability, Network Density, and Energy Efficiency for Wireless Sensor Networks.

A wireless sensor network (WSN) is emerging as an innovative method for gathering information that will significantly improve the reliability and efficiency of infrastructure systems. Broadcast is a common method to disseminate information in WSNs. A variety of counter-based broadcast schemes have been proposed to mitigate the broadcast-storm problems, using the count threshold value and a random access delay. However, because of the limited propagation of the broadcast-message, there exists a trade-off in a sense that redundant retransmissions of the broadcast-message become low and energy efficiency of a node is enhanced, but reachability become low. Therefore, it is necessary to study an efficient counter-based broadcast scheme that can dynamically adjust the random access delay and count threshold value to ensure high reachability, low redundant of broadcast-messages, and low energy consumption of nodes. Thus, in this paper, we first measure the additional coverage provided by a node that receives the same broadcast-message from two neighbor nodes, in order to achieve high reachability with low redundant retransmissions of broadcast-messages. Second, we propose a new counter-based broadcast scheme considering the size of the additional coverage area, distance between the node and the broadcasting node, remaining battery of the node, and variations of the node density. Finally, we evaluate performance of the proposed scheme compared with the existing counter-based broadcast schemes. Simulation results show that the proposed scheme outperforms the existing schemes in terms of saved rebroadcasts, reachability, and total energy consumption.

Impact of Carbohydrate Counting Errors on Glycemic Control in Type 1 Diabetes

Abstract Patients with type 1 diabetes mellitus (T1DM) typically determine their bolus insulin needs based on methods from Advanced Carbohydrate Counting (ACC). In ACC the amount of required bolus insulin is assumed to be directly proportional to the carbohydrate content of the ingested meal. It is well known that many T1DM patients have difficulties to accurately estimate meal carbohydrates. Though these estimates are used for calculating the meal bolus amount, there is a scarcity of data on how estimation errors affect glycemic control. The current paper analyzes the effect of carb counting errors on glycemic outcomes during basal-bolus-therapy in a simulation study using so-called Deviation Analyses. Furthermore, the effect of inaccurate estimates on the settings of the insulin therapy is studied by means of the previously published Adaptive Bolus Calculator (ABC) algorithm. It is found that whereas random carb counting inaccuracies indeed do lead to an inferior glycemic control, systematic biases in the estimates are expected to hardly affect the results since these are usually implicitly accounted for in the therapy settings.

Chronic Use of Anabolic Steroids and the Effects on the Neuronal Density of the Cerebral Cortex and Hippocampus in Mice

This study analyzed the effects of the chronic use of these drugs on the neuronal density of mice cerebral cortex and hippocampus. Materials and methods: 40 male Swiss mice were used, divided into 4 groups (n=10): GI-Control (0,02ml/Kg/week of saline solution), GII- treated with anabolic steroid Durateston® (83,3mg/Kg/week) GIII- treated with anabolic steroid Deca Durabolin® (16,6mg/Kg/week) e GIV- treated with the two anabolic steroids, concomitantly. The mice were treated for sixty days (60) and practiced swimming three times a week. The brain fragments were processed following the standardized sequence in conventional histological procedures and stained using cresyl violet. For the neuronal density analysis, the simple random count methodology was used. Results: Data revealed a significant reduction in the neuronal density of the groups treated with anabolic steroids, the limbic area had an estimated decrease of 16.44% in group III and 29.21% in group IV; the motor area the groups II, III, and IV presented a reduction of 17.63%, 15.35%, and 12.23%, and in the sensory area 15.22%, 16.41% and 21.59%, respectively; the groups II, III, and IV of the Ca1 area of the hippocampus showed a neuronal loss of 23.5%, 27.8%, and 36.36%, while groups II, III and IV of the Ca2 area there was a reduction of 10.37%, 11.83%, and 16.34%. In conclusion, the chronic use of AAS can be harmful to the nervous system since the neuronal reduction can bring structural and functional damages with possible consequences the whole organism.

Higher order net-proton number cumulants dependence on the centrality definition and other spurious effects

We study the dependence of the normalized moments of the net-proton multiplicity distributions on the definition of centrality in relativistic nuclear collisions at a beam energy of . Using the ultra relativistic quantum molecular dynamics model as event generator we find that the centrality definition has a large effect on the extracted cumulant ratios. Furthermore we find that the finite efficiency for the determination of the centrality introduces an additional systematic uncertainty. Finally, we quantitatively investigate the effects of event-pile up and other possible spurious effects which may change the measured proton number. We find that pile-up alone is not sufficient to describe the data and show that a random double counting of events, adding significantly to the measured proton number, affects mainly the higher order cumulants in most central collisions.

PERSPECTIVES FOR SURROGATE SAFETY STUDIES IN EAST-EUROPEAN COUNTRIES

The road safety development in East-European countries follows in general the trends of the western countries, even though there is a time lag. The fatality numbers are decreasing, though the improvements for the vulnerable road users are less impressive compared to other road user categories. The traditional road safety analysis based on accident history has many limitations related to accident under-reporting, low and random accident counts at individual sites and lack of details in the police or hospital reports. The surrogate safety methods are based on observation of other- than-accident occurrences that still have a strong relation to safety in traffic. Such methods are often more efficient (and pro-active) for safety assessments. The paper reviews the current status of the surrogate safety analysis methods, the challenges, and opportunities related to modern urban traffic conditions and the emerging technologies for more efficient data collection. The method is put in the context of the East-European countries to see how it contribute to the on-going road safety work and a better understanding of accidents risk factors necessary for producing effective safety counter-measures.

Effects of a novel tungsten-impregnated rubber neck shield on the quality of cerebral images acquired using 15O-labeled gas.

The present study aimed to validate the effects of a novel tungsten-impregnated rubber neck shield on the quality of phantom and clinical 15O-labeled gas positron emission tomography (PET) images. Images were acquired in the presence or absence of a neck shield from a cylindrical phantom containing [15O]H2O (phantom study) and from three individuals using [15O]CO2, [15O]O2 and [15O]CO gas (clinical study). Data were acquired in three-dimensional (3D) mode using a Discovery PET/CT 710. Values for cerebral blood flow, cerebral blood volume, oxygen extraction fraction, and cerebral metabolic rate of oxygen with and without the neck shield were calculated from 15O-labeled gas images. Arterial radioactivity and count characteristics were evaluated in the phantom and clinical studies. The coefficient of variance (CV) for the phantom study and the standard deviation (SD) for functional images were also analyzed. The neck shield decreased the random count rates by 25-59% in the phantom and clinical studies. The noise equivalent count rate (NECR) increased by 44-66% in the phantom and clinical studies. Random count rates and NECR in [15O]CO2 images significantly differed with and without the neck shield. The improvement in visual and physical image quality with the neck shield was not observed in the phantom and clinical studies. The novel neck shield reduced random count rate and improved NECR in a 3D PET study using 15O-labeled gas. The image quality with the neck shield was similar to that without the neck shield.

Frequency of Frequencies Distributions and Size-Dependent Exchangeable Random Partitions

ABSTRACTMotivated by the fundamental problem of modeling the frequency of frequencies (FoF) distribution, this article introduces the concept of a cluster structure to define a probability function that governs the joint distribution of a random count and its exchangeable random partitions. A cluster structure, naturally arising from a completely random measure mixed Poisson process, allows the probability distribution of the random partitions of a subset of a population to be dependent on the population size, a distinct and motivated feature that makes it more flexible than a partition structure. This allows it to model an entire FoF distribution whose structural properties change as the population size varies. An FoF vector can be simulated by drawing an infinite number of Poisson random variables, or by a stick-breaking construction with a finite random number of steps. A generalized negative binomial process model is proposed to generate a cluster structure, where in the prior the number of clusters is finite and Poisson distributed, and the cluster sizes follow a truncated negative binomial distribution. We propose a simple Gibbs sampling algorithm to extrapolate the FoF vector of a population given the FoF vector of a sample taken without replacement from the population. We illustrate our results and demonstrate the advantages of the proposed models through the analysis of real text, genomic, and survey data. Supplementary materials for this article are available online.

A new spatial and flexible multivariate random-coefficients model for the analysis of pedestrian injury counts by severity level

We propose in this paper a spatial random coefficients flexible multivariate count model to examine, at the spatial level of a census tract, the number of pedestrian injuries by injury severity level. Our model, unlike many other macro-level pedestrian injury studies in the literature, explicitly acknowledges that risk factors for different types of pedestrian injuries can be very different, as well as accounts for unobserved heterogeneity in the risk factor effects. We also recognize the multivariate nature of the injury counts by injury severity level within each census tract (as opposed to independently modeling the count of pedestrian injuries by severity level). In concrete methodological terms, our model: (a) allows a full covariance matrix for the random coefficients (constant heterogeneity, or CH, and slope heterogeneity, or SH, effects) characterizing spatial heterogeneity for each count category, (b) addresses excess zeros (or any other excess count value for that matter) within a multivariate count setting in a simple and elegant fashion, while recognizing multivariateness engendered through covariances in both the CH and SH effects, (c) accommodates spatial dependency through a spatial autoregressive lag structure, allowing for varying spatial autoregressive parameters across count categories, and (d) captures spatial drift effects through the spatial structure on the constants and the slope heterogeneity effects. To our knowledge, this is the first time that such a general spatial multivariate model has been formulated. For estimation, we use a composite marginal likelihood (CML) inference approach that is simple to implement and is based on evaluating lower-dimensional marginal probability expressions.The data for our analysis is drawn from a 2009 pedestrian crash database from the Manhattan region of New York City. Several groups of census tract-based risk factors are considered in the empirical analysis based on earlier research, including (1) socio-demographic characteristics, (2) land-use and road network characteristics, (3) activity intensity characteristics, and (4) commute mode shares and transit supply characteristics. The empirical analysis sheds light on both engineering as well as behavioral countermeasures to reduce the number of pedestrian-vehicle crashes by severity of these crashes.

Characterization of 176Lu background in LSO-based PET scanners

LSO and LYSO are today the most common scintillators used in positron emission tomography. Lutetium contains traces of 176Lu, a radioactive isotope that decays β− with a cascade of γ photons in coincidence. Therefore, Lutetium-based scintillators are characterized by a small natural radiation background. In this paper, we investigate and characterize the 176Lu radiation background via experiments performed on LSO-based PET scanners. LSO background was measured at different energy windows and different time coincidence windows, and by using shields to alter the original spectrum. The effect of radiation background in particularly count-starved applications, such as 90Y imaging, is analysed and discussed. Depending on the size of the PET scanner, between 500 and 1000 total random counts per second and between 3 and 5 total true coincidences per second were measured in standard coincidence mode. The LSO background counts in a Siemens mCT in the standard PET energy and time windows are in general negligible in terms of trues, and are comparable to that measured in a BGO scanner of similar size.

Religious and Spiritual Support, Reentry, and Risk

Systems and agencies intent on pursuing an evidence-based approach to correctional interventions have widely adopted the risk principle. For a variety of reasons, many studies have found that giving treatment to low risk people has little impact on reducing recidivism and can even increase recidivism. Because of the risk principle, many prison and community correctional systems now target their treatment resources to medium and high risk. This study tests whether the effects of religious/spiritual support on reentry success generalize across offenders as a function of risk. Results from random effects count models suggest that religious and spiritual support does have a strong and robust effect on the likelihood of ex-offenders desisting from substance abuse. Findings also reveal that the risk principle was not supported; religious and social support was associated with significantly lower levels of substance abuse among low risk offenders, but not among higher-risk offenders. On the other hand, religious and spiritual support did not significantly relate to criminal offending at any risk level. Implications for religious programming and services, as well as the study of religion and reentry, are discussed.

Influence of resin-modified glass ionomer and topical fluoride on levels of Streptococcus mutans in saliva and biofilm adjacent to metallic brackets.

Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM) in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC) (Fuji ORTHO LC) and a light cured composite resin (Transbond XT), and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF) on SM counts. In a parallel study design, two groups (n=14/15) were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

Pilot feasibility study of Heart2HAART: a smartphone application to assist with adherence among substance users living with HIV

ABSTRACTBackground: Smartphones with programmable apps may offer innovative interactive interventions for improving adherence among people living with HIV with substance use problems. Methods: This pilot randomized controlled trial sought to primarily determine the usability and feasibility of using a smartphone-based intervention called Heart2HAART as an adjunct to directly observed treatment with adherence counseling compared to directly observed treatment with adherence counseling alone among those with HIV and a history of substance use over a three-month time frame. Participants in the Heart2HAART condition completed an additional survey on usability and acceptability. Adherence was measured using unannounced pill counts assessed via a phone call. Results: Twenty-eight participants were randomized to receive Heart2HAART (n = 19) or control (n = 9). All were receiving either weekly (n = 9) or daily (n = 19) observed treatment. Among those randomized to Heart2HAART, 63.2% reported no difficulty using the Heart2HAART smartphone application and 94.7% responded that the medication reminders did not interfere negatively with their activities. On average participants used Heart2HAART application 56.8 times over the three-month trial. In analyses adjusting for age, there was no difference in adherence to HAART medication between the Heart2HAART and control group as evaluated by the random pill count assessment (P = .29). Conclusions: Heart2HAART was feasible to use during a three-month pilot trial. Future studies may evaluate a more tailored approach, with more robust contingency management.

Evaluation of Bobwhite Quail Surveys in Kansas

Statistical analysis of selected Kansas bobwhite (Colinus virginianus) population and harvest surveys is presented. Survey techniques evaluated include roadside counts by rural mail carriers (RMCS), April roadside counts, whistling cock counts, random summer brood counts (RSBC), interviews of hunters contacted during the hunting season, wing collection envelopes distributed to hunters, and a mail questionnaire harvest survey of hunters. Significant differences (P < 0.05) between years and between survey regions existed for the April RMCS, April roadside count (coveys/observer), June whistle count, RSBC (young/adult and young/adult hen), and July RMCS, Correlation tests indicated significant (P < O, 1 to 0.001) correlation coefficient (r) values between many of the population surveys, and between many of the population surveys and harvest parameters. The October RMCS is the best single predictor of harvest parameters. When the October RMCS (quail/100 miles) is used in association with adults/observer (RSBC) and total quail/observer (RSBC), higher R2 values are obtained as determined by stepwise multiple regression with harvest parameters,