General Distribution Research Articles

A new species of Dilophochila Bates, 1888 with comments on natural history and distribution of the genus (Coleoptera: Melolonthidae: Rutelinae)

A new species, Dilophochila glabra sp. nov. is described from the Sierra Norte, Oaxaca, Mexico. Diagnosis and images (dorsal, lateral and ventral habitus, and genitalia) of the taxonomic characters are provided. Affinities with their closest congeners and the general distribution pattern of the genus are discussed, considering that it presents a typical Mountain Paleoamerican sub-pattern. The modifications in the mouthparts of this genus due to the specialization in the intake of pine needles are commented, as well as in two other different taxa within Anomalini.

Modeling Symmetric and Asymmetric Volatility in Nifty 50 Index Futures Market

Volatility in stock markets is a matter of concern for investors and policymakers across the world. Derivatives enable traders to manage risk arising out of volatility through hedging and arbitrage (Singh & Kansal, 2010). During times of high volatility, regulatory authorities step in to curb the frenzied activity in the stock market. Time series data of financial nature shows non-normality traits. Thus, it is essential to check whether distributions other than normal distribution can perfectly analyze the time series data. Therefore, it becomes important to use the appropriate methods to model volatility. This study aims to analyse both symmetric and asymmetric volatility in Nifty 50 futures markets. Different variants of GARCH models were used in the study under three probability distributions such as normal, Student’s-t, and generalized error distribution (GED). EGARCH (1,1) model with Student’s- t distribution proved to be the best model for capturing volatility as it had the lowest AIC value. The results detected the presence of a leverage effect and thereby confirmed that negative news created more volatility than positive news.

Yaşlı Kullanıcılar İçin Yerinde Yaşlanması Destekleyen Konutlarda İç Mekân

One of the effective factors in enabling individuals to age in place and to spend their old age periods more actively and with better quality is the physical environmental characteristics of the dwelling and its immediate surroundings. In this study, which is based on the assertion that individuals prefer to live in their own homes in old age, it is aimed to determine the features that should be carried by the houses that will support the aging in place of elderly individuals and to reveal the design principles. For this purpose, semi-structured interviews were conducted with 70 elderly users aged 65 and over in their residences. General frequency distributions and chi-square test analyses of the obtained data were performed in SPSS statistical program and descriptive content analysis was performed on open-ended questions and the data were examined with the comparison tables created. Then, all the data obtained from the field study are evaluated together with the literature information and the principles that should be considered in the renovation of the houses for the use of elderly users in line with the new needs are presented. With the design principles presented, it is envisaged that elderly users will continue their lives in a better quality and active way in their residences by extending the time they can be self-sufficient. This work was supported by Office of Scientific Research Projects of Karadeniz Technical University. Project number: FYL-2020-8518.

Minimizations of positive periodic and Dirichlet eigenvalues for general indefinite Sturm-Liouville problems

The aim of this paper is to develop an analytical approach to obtain the sharp estimates for the lowest positive periodic eigenvalue and all Dirichlet eigenvalues of a general Sturm-Liouville problemy″=q(t)y+λm(t)y, where q is a nonnegative potential and another potential m admits to change sign. A typical example of such problems is the well-known Camassa-Holm equations with indefinite potentials, which corresponds to the case q(t)≡14. It is shown that the solution of the minimization problems of the lowest positive periodic eigenvalues and Dirichlet eigenvalues will lead to more general distributions of potentials which have no densities with respect to the Lebesgue measure. As a result, it is very natural to choose the general setting of the measure differential equationsdy•=y(t)dμ(t)+λydν(t), to understand the eigenvalues and their minimization, where μ and ν are two suitable measures. The variational characterization of lowest positive eigenvalues, together with a strong continuous dependence of eigenvalues on the potentials, will play crucial roles in our analysis. Different from the periodic case, we are able to obtain the optimal bounds for higher Dirichlet eigenvalues.

Distribution of macrophages in the developing cochlea of the common marmoset, a primate model animal.

Macrophages are essential immune cells in the cochlea that contribute to inflammation, tissue repair, and homeostasis. They also play an important role in local cochlear immunity. The developmental immigration and maturation of macrophages in the cochlea have been investigated and are considered essential for normal hearing acquisition. Most of our current knowledge regarding cochlear development is based on rodent models because of the ethical challenges of using human fetal samples for research. However, inter-species differences between rodents and humans have been reported. In this study, we used a primate animal model to investigate the distributions of macrophages in the developing cochlea. The common marmoset (Callithrix jacchus), a small monkey species that inhabits the New World, was used as the model. We investigated the distribution of macrophages in the developing cochlea of the common marmoset by performing immunohistochemical analyses of cochlear tissue from common marmoset embryos at different development stages. We revealed detailed distribution changes in the macrophages of a primate animal model cochlea. This observation indicates that most of the changes in the general distribution of macrophages were well preserved between rodents and this primate. The distribution changes observed in the common marmoset were also compatible with observations in the human fetus; although, observations in the human fetus are limited. Our observations in this study also revealed several differences between common marmosets and rodents. The time course of immunological development and maturations established in this study will aid in the study of the primate-specific developmental biology of the inner ear. These observations may eventually lead to new therapeutic strategies for hearing loss in humans. In addition, understanding the immunological steady-state of the cochlea may help in the study of age- and genetic-induced hearing loss and in the design of regenerative therapies.

Expansion-free cluster of stars in modified Gauss–Bonnet gravity

The aim of this paper is to investigate the expansion-free model of star cluster in modified Gauss-Bonnet gravity. To achieve this, we analyze a model of a star cluster which is dissipative, anisotropic and viscous. The modified field equations as well as junction conditions are applied in order to study the general distribution of anisotropic fluid exhibiting dissipation with varying dominant stress components. We also integrate the condition of vanishing expansion into our analysis. To gain insight into the significance of motion that does not involve expansion, we discuss two distinct ways of defining the radial velocity of a fluid element. The study demonstrates the emergence of a cavity in the evolution of star clusters when expansion is not present. Moreover, we determine the shear-free and expansion-free collapse of the star cluster by analyzing the relative velocity among adjacent fluid layers. The Skripkin model can be used to represent an expansion-free, non-dissipative, and isotropic star cluster. This provides a valuable tool for investigating the properties and behavior of these celestial bodies. The Skripkin model demonstrates homologous evolution for the shear-free case. We conclude that the exotic matter present in f(G,T) gravity are essential for understanding the dynamics of star cluster’s evolution. This indicates that the dark source terms should be taken into account when investigating the properties and behavior of the celestial bodies.

Temporally stacked bee forage species distribution modeling for flower abundance mapping

Predicting spatial distribution of flowering forage availability is critical for guiding migratory beekeeping decisions.Species distribution modelling (SDM) is widely used to predict the geographic distribution or species ranges. Stacked distributions of multiple species (S-SDM) have been used in predicting species richness or assemblages. Here, we present a method for stacking SDMs based on a temporal element, the flowering phenology of melliferous flora species. First, we used presence-only data for thirty key forage species used for honey production in Western Australia, combined with environmental variables for predicting the geographic distribution of species, using MaxEnt software. The output distribution grids were then stacked based on monthly flowering times of each species to develop grids representing the richness of flowering species by grid cell. While designed for modelling flowering forage availability for a migratory beekeeping system, the approach can be used for predicting temporal forage availability for a range of different fauna that rely on melliferous flora.•How to use temporally stacked species distribution modelling for generic distribution of flowering availability using presence-only data.•A procedure for developing flowering richness and availability grids.

The lophogastrids (Crustacea: Peracarida: Lophogastrida) of Indonesia and its adjacent waters. An updated checklist.

The zoogeographic distribution of lophogastrid species (Crustacea: Peracarida: Lophogastrida) occurring in the Indonesian waters is presented. For each species, data on general distribution, bathymetric ranges, habitat and localities reported on published data are provided. A total of 20 lophogastrid species belonging to three families and seven genera occur in Indonesian waters (about 38% of all known lophogastrids species worldwide), a number greater than other areas of Southeast Asia. Also, based on current information, the number of species or species richness is greater than other regions, such as Madagascar, North Pacific off Japan, Mediterranean, Canary Island, northern mid-Atlantic ridge, Iberian Peninsula, Mexico, and Angola Basin (SE Atlantic). Most of the Indonesian species are distributed worldwide, but one species, Lophogaster inermis appears to be endemic to Indonesia. Previous listings of Paralophogaster intermedius occurring in Southeast Asian waters is not verified in any collections, and has therefore been removed from our updated list.

Analysis of a Collision-Affected M/GI/1/ /N Retrial Queuing System Considering Negative Customers and Transmission Errors

This paper considers a retrial G-queue with collisions, transmission errors, and a finite number of sources, where service and repair time are both general distributions. The number of sources (terminals) is finite and a source cannot generate new requests until the channel (server) finishes its work, i.e., the rate at which new primary requests are generated varies inversely with the number of data frame (customer) in the system. A collision occurs when service requests arrive at a busy channel, and transmission errors prevent data frames from leaving the system after completing service. Two types of arrivals are considered. Negative customers will break down the system in the busy state and remove the customer under service. The application of our model is indicated, with a particular emphasis on communication networks such as the local-area networks (LAN) with CSMA/CD protocol. Recursive formulas have been derived to calculate the stationary joint distributions and the Laplace transform of reliability function by applying the discrete transformations method along with the supplementary variables technique (SVT). Furthermore, the comparative performance and reliability analysis have been conducted numerically. Numerical examples are provided to investigate the sensitivity of different parameters on performance measures and reliability indicators.

Contribution to the knowledge of the oribatid mite genus Arthrovertex (Acari, Oribatida, Scutoverticidae), with description of a new arboreal species from Vietnam

ABSTRACT A new arboreal species of Arthrovertex (Oribatida, Scutoverticidae)—A. kornilovi sp. nov.—is described, based on adults collected from tree branches of Dipterocarpus alatus in Cat Tien National Park, Vietnam. A generic diagnosis, identification key, distribution, and habitats of representatives of Arthrovertex are presented. http://zoobank.org/urn:lsid:zoobank.org:pub:15169867-0FAB-43D6-94F4-9D3B4F4A9F47

Multimodal diffusion model for increments of electroencephalogram data

AbstractWe propose a new strictly stationary strong mixing diffusion model with marginal multimodal (three-peak) distribution and exponentially decaying autocorrelation function for modeling of increments of electroencephalogram data collected from Ugandan children during coma from cerebral malaria. We treat the increments as discrete-time observations and construct a diffusion process where the stationary distribution is viewed as a mixture of three non-central generalized Gaussian distributions and we state some important properties related to the moments of this mixture. We estimate the distribution parameters using the expectation-maximization algorithm, where the added shape parameter is estimated using the higher order statistics approach based on an analytical relationship between the shape parameter and kurtosis. The derived estimates are then used for prediction of subsequent neurodevelopment and cognition of cerebral malaria survivors using the elastic net regression. We compare different predictive models and determine whether additional information obtained from multimodality of the marginal distributions can be used to improve the prediction.

A checklist of the dacine fruit flies (Diptera, Tephritidae, Dacinae) of Mozambique

Here we present a checklist of all records of dacine fruit flies (Diptera: Tephritidae: Dacinae) from Mozambique, based on verified specimen records in natural history collections and literature records. In total, 57 Dacinae species are recorded from Mozambique, of which only one is considered endemic. This relatively low species diversity compared to other African countries appears to be related to incomplete sampling. For each species the localities from which it was recorded are given (including geocoordinates), or a general distribution is provided. The checklist is discussed briefly in terms of species richness, endemism and geographic distribution.

Bayesian Analysis of Change Point Problems Using Conditionally Specified Priors

In data analysis, change point problems correspond to abrupt changes in stochastic mechanisms generating data. The detection of change points is a relevant problem in the analysis and prediction of time series. In this paper, we consider a class of conjugate prior distributions obtained from conditional specification methodology for solving this problem. We illustrate the application of such distributions in Bayesian change point detection analysis with Poisson processes. We obtain the posterior distribution of model parameters using general bivariate distribution with gamma conditionals. Simulation from the posterior are readily implemented using a Gibbs sampling algorithm. The Gibbs sampling is implemented even when using conditional densities that are incompatible or only compatible with an improper joint density. The application of such methods will be demonstrated using examples of simulated and real data.

Hierarchical Reliability Modelling and Analysis of Life Support System of Fighter Aircraft

The paper proposes a hierarchical reliability modelling and assessment approach for a life support system (LSS) that provides oxygen to the pilot and is employed in a combat aircraft. The system has the primary function of generating oxygen onboard, and it has a backup gaseous oxygen tank as redundancy. An emergency oxygen bottle is also part of the ejection seat for emergency use. Both backup oxygen and emergency oxygen have a fixed capacity and a fixed duration of oxygen supply. Therefore, it is crucial to assess the reliability of the LSS to ensure its safety and effectiveness of this LSS during a mission by the combat aircraft. The proposed reliability model of LSS is developed as a two-level hierarchical model, that captures the inherent randomness in the operation of the system. At the lowest level of the hierarchy, Markov chains are used to model the events that may lead to the failure of the LSS. The events include the failure of individual components, the depletion of backup oxygen, and the depletion of emergency oxygen. The Markov chains consider the interactions between individual components and events during the mission profile. At the top level of the hierarchy, a fault tree is used to model the interactions between various events during the mission profile. The fault tree considers the interactions between individual events and the effects of redundancy on the reliability of the LSS. The results of the Markov chains at the lower level are exported to the higher level modelled via fault tree to find the overall system reliability. The reliability model is further extended to incorporate the deterministic nature of the LSS due to the fixed capacity of the backup tank and emergency bottle. The work addresses the modelling of six different scenarios of LSS operations. The modelling of these scenarios is achieved using Semi-Markov Processes (SMP), which allow the state holding time to be a general distribution.

Stragglers of the thick disc

Young alpha-rich (YAR) stars have been detected in the past as outliers to the local age − [α/Fe] relation. These objects are enhanced in α-elements, but they are apparently younger than typical thick disc stars. Here, we study the global kinematics and chemical properties of YAR giant stars in the APOGEE DR17 survey and show that they have properties similar to those of the standard thick disc stellar population. This leads us to conclude that YAR are rejuvenated thick disc objects, and the most likely explanation is that they are evolved blue stragglers. This is confirmed by their position in the Hertzsprung–Russel diagram (HRD). Extending our selection to dwarfs allowed us to obtain the first general straggler distribution in an HRD of field stars. We also compared the elemental abundances of our sample with those of standard thick disc stars and found that our YAR stars are shifted in oxygen, magnesium, sodium, and the slow neutron-capture element cerium. Although we detected no sign of binarity for most objects, the enhancement in cerium may be a signature of a mass transfer from an asymptotic giant branch companion. The most massive YAR stars suggest that mass transfer from an evolved star may not be the only plausible formation pathway and that other scenarios, such as collision or coalescence, should be considered.

Phase Spaces, Parity Operators, and the Born–Jordan Distribution

Phase spaces as given by the Wigner distribution function provide a natural description of infinite-dimensional quantum systems. They are an important tool in quantum optics and have been widely applied in the context of time–frequency analysis and pseudo-differential operators. Phase-space distribution functions are usually specified via integral transformations or convolutions which can be averted and subsumed by (displaced) parity operators proposed in this work. Building on earlier work for Wigner distribution functions (Grossmann in Commun Math Phys 48(3):191–194, 1976. https://doi.org/10.1007/BF01617867), parity operators give rise to a general class of distribution functions in the form of quantum-mechanical expectation values. This enables us to precisely characterize the mathematical existence of general phase-space distribution functions. We then relate these distribution functions to the so-called Cohen class (Cohen in J Math Phys 7(5):781–786, 1966. https://doi.org/10.1063/1.1931206) and recover various quantization schemes and distribution functions from the literature. The parity operator approach is also applied to the Born–Jordan distribution which originates from the Born–Jordan quantization (Born and Jordan in Z Phys 34(1):858–888, 1925. https://doi.org/10.1007/BF01328531). The corresponding parity operator is written as a weighted average of both displacements and squeezing operators, and we determine its generalized spectral decomposition. This leads to an efficient computation of the Born–Jordan parity operator in the number-state basis, and example quantum states reveal unique features of the Born–Jordan distribution.

Spatiotemporal distribution and particle–water partitioning of polycyclic aromatic hydrocarbons in Bohai Sea, China

The Bohai Sea is one of the most polluted marine areas in China with polycyclic aromatic hydrocarbons (PAHs) due to its unique hydrological and geographical environment. To investigate differences in PAH concentrations, composition, and particle–water partitioning before and after the rainy reason, water samples were collected during two surveying voyages covering most of the area of the Bohai Sea. Total and dissolved PAH concentrations were higher during the June voyage (total PAHs: 32.29 ± 15.18 ng/L, dissolved PAHs: 31.25 ± 15.26 ng/L) than the August voyage (total PAHs: 15.98 ± 6.39 ng/L, dissolved PAHs: 11.21 ± 5.59 ng/L). The opposite trend was observed for particulate PAHs (June: 1.04 ± 1.01 ng/L, August: 4.78 ± 2.96 ng/L). Among particulate PAHs, an unusually high proportion (65.07%) of low-molecular-weight (LMW) PAHs was observed during the August voyage, which was significantly higher than the proportion during the June voyage (21.86%). This high proportion was inconsistent with the general distribution of PAHs in the aquatic environment according to their physicochemical properties. The excess LMW PAHs adsorbed on suspended particulate matter arose mainly from soil affected by the petrochemical industry of the Bohai Economic Rim, and were carried with particles on runoff into the Bohai Sea during the rainy season. An estimated 5.49 t of LMW PAHs transitioned from the particulate phase to the dissolved phase during the rainy season. This transfer of LMW PAHs from coastal soil to the water column may be an important source of PAHs in the Bohai Sea.

Population norms for the EQ-5D-3L and EQ-5D-5L in Romania

BackgroundThe majority of patient reported outcome measures (PROMs) don’t have population norms in Romania. This is the case with the EQ-5D as well. Therefore, we aimed to estimate population norms for the Romanian versions of the EQ-5D-5L, EQ-5D-3L, their indexes, and the EQ-VAS.MethodsA cross-sectional survey was conducted in all regions of Romania from November 2018 to November 2019. A three-stage probability sampling procedure stratified by region and settlement size was used to select a representative sample. Interviews were computer-assisted and conducted in respondents’ homes by trained interviewers. Health status was assessed with the EQ-5D-5L, the EQ-5D-3L and the EQ VAS. Descriptive statistics were used to estimate population norms by age groups and sex for the EQ-5D-5L, the EQ-5D-3L, their indexes and the EQ VAS. Population norms were weighted using survey weights. Indexes for the EQ-5D questionnaires were estimated using the recently developed Romanian value sets.ResultsData from 1,649 interviews was analysed in the present study. Survey weights were used so that sex and place of residence ratios for the weighted sample matched the Romanian general population distribution. Participants’ mean age was 47.4 years (SE = 1.157) and 50.3% of them reported being in good health. The dimension for which people reported the highest number of problems for both questionnaires was the pain/discomfort dimension. Men aged 35 plus reported fewer problems with pain/discomfort than women for both the EQ-5D-5L and EQ-5D-3L. Health decreased with age as shown by the decrease from age group 18–24 to age group 75 plus in the indexes of both questionnaires: from 0.977 (SE = 0.005) to 0.765 (SE = 0.017) for EQ-5D-5L and from 0.981 (SE = 0.005) to 0.784 (SE = 0.019) for EQ-5D-3L. There was 29.9 points drop in the EQ VAS score between the youngest and oldest group.ConclusionsPopulation norms for the Romanian versions of the EQ-5D-5L, EQ-5D-3L, their indexes, and the EQ VAS are now available. These can now be used as reference values by healthcare professionals, researchers and decision-makers leading to a further development of health-related quality of life research in Romania.

HIV models with non‐exponential probability distributed infection progression

Existing HIV infection dynamics models are based on the classical target cell‐infected cell‐free virus compartment model. In fact, in order to facilitate modeling and dynamical analysis, these models assume that the probability of infected cells staying in different infection stages obeys an exponential distribution. However, this does not accurately describe the process of HIV infection from target cells to budding of virus, that is, fusion‐reverse transcription‐reproductivity formation‐budding process. Therefore, to expand the idea of HIV modeling, in this paper, we first establish the HIV integral‐differential equation model that obeys the general distribution, and then degenerate the model into a subclass ODEs model under the assumption of gamma distribution. Finally, an equivalent age structure model is given, and numerical simulations are conducted to describe the integral‐differential equations model. It is worth mentioning that ODEs models with subclasses can provide good numerical implementations for age structure as well as other PDEs HIV models. This is another important purpose of our work.

A general size-biased distribution

Abstract We generalize a size-biased distribution related to the Riemann xi-function using the work of Ferrar. Some analysis and properties of this more general distribution are offered as well.