Complementary Distributions Research Articles

Cluster formation induced by a cloud–cloud collision in [DBS2003]179

Abstract [DBS2003]179 is a super star cluster in the Galaxy discovered in deep near-infrared observations. We carried out CO J = 1–0 and J = 3–2 observations of the region of [DBS2003]179 with NANTEN2, ASTE, and the Mopra 22 m telescope. We identified and mapped two molecular clouds that are likely to be associated with the cluster. This association is supported by the spatial correlation with the corresponding 8$\, \mu$m Spitzer image and by a high ratio of the two transitions of $^{12}$CO(J = 3–2 and J = 1–0). The two clouds show complementary distributions in space, and bridging features connect them in velocity. We hypothesize that the two clouds collided with each other 1–2 Myr ago and that the collision compressed the interfacial layer, triggering the formation of the cluster. This offers an additional piece of evidence for a super star cluster formed by a cloud–cloud collision, alongside the four super star clusters Westerlund$\:2$, NGC 3603, RCW 38, and R 136. These findings indicate that the known super star clusters with closely associated dust emission were formed by cloud–cloud collisions, lending support to the important role of cloud–cloud collisions in high-mass star formation.

High-mass star formation in Orion possibly triggered by cloud–cloud collision. III. NGC 2068 and NGC 2071

AbstractUsing the NANTEN2 Observatory, we carried out a molecular-line study of high-mass star forming regions with reflection nebulae, NGC 2068 and NGC 2071, in Orion in the $^{13}$CO($J = 2$–1) transition. The $^{13}$CO distribution shows that there are two velocity components at ${9.0}$ and ${10.5}\:$km$\:$s$^{-1}$. The blue-shifted component is in the northeast associated with NGC 2071, whereas the red-shifted component is in the southwest associated with NGC 2068. The total intensity distribution of the two clouds shows a gap of $\sim\!\! 1\:$pc, suggesting that they are detached at present. A detailed spatial comparison indicates that the two show complementary distributions. The blue-shifted component lies toward an intensity depression to the northwest of the red-shifted component, where we find that a displacement of ${0.8}\:$pc makes the two clouds fit well with each other. Furthermore, a new simulation of non-frontal collisions shows that observations from $60^\circ$ off the collisional axis agreed well with the velocity structure in this region. On the basis of these results, we hypothesize that the two components collided with each other at a projected relative velocity of ${3.0}\:$km$\:$s$^{-1}$. The timescale of the collision is estimated to be ${0.3}\:$Myr for an assumed axis of the relative motion $60^\circ$ off the line of sight. We assume that the two most massive early B-type stars in the cloud, illuminating stars of the two reflection nebulae, were formed by collisional triggering at the interfaces between the two clouds. Given the other young high-mass star-forming regions, namely, M 42, M 43, and NGC 2024 (Fukui et al. 2018a, ApJ, 859, 166; Ohama et al. 2017, arXiv: 1706.05652), it seems possible that collisional triggering has been independently working to form O-type and early B-type stars in Orion in the last Myr over a projected distance of ∼80 pc.

Acoustic emissions in compression of building materials: q-statistics enables the anticipation of the breakdown point

In this paper we present experimental results concerning Acoustic Emission (AE) recorded during cyclic compression tests on two different kinds of brittle building materials, namely concrete and basalt. The AE inter-event times were investigated through a non-extensive statistical mechanics analysis which shows that their complementary cumulative probability distributions follow q -exponential laws. The entropic index q and the relaxation parameter β q ≡ 1∕T q , obtained by fitting the experimental data, exhibit systematic changes during the various stages of the failure process, namely (q , T q ) linearly align. The T q = 0 point corresponds to the macroscopic breakdown of the material. The slope, including its sign, of the linear alignment appears to depend on the chemical and mechanical properties of the sample. These results provide an insight on the warning signs of the incipient failure of building materials and could therefore be used in monitoring the health of existing structures such as buildings and bridges.

Detectability of cerebellar activity with magnetoencephalography and electroencephalography.

Electrophysiological signals from the cerebellum have traditionally been viewed as inaccessible to magnetoencephalography (MEG) and electroencephalography (EEG). Here, we challenge this position by investigating the ability of MEG and EEG to detect cerebellar activity using a model that employs a high‐resolution tessellation of the cerebellar cortex. The tessellation was constructed from repetitive high‐field (9.4T) structural magnetic resonance imaging (MRI) of an ex vivo human cerebellum. A boundary‐element forward model was then used to simulate the M/EEG signals resulting from neural activity in the cerebellar cortex. Despite significant signal cancelation due to the highly convoluted cerebellar cortex, we found that the cerebellar signal was on average only 30–60% weaker than the cortical signal. We also made detailed M/EEG sensitivity maps and found that MEG and EEG have highly complementary sensitivity distributions over the cerebellar cortex. Based on previous fMRI studies combined with our M/EEG sensitivity maps, we discuss experimental paradigms that are likely to offer high M/EEG sensitivity to cerebellar activity. Taken together, these results show that cerebellar activity should be clearly detectable by current M/EEG systems with an appropriate experimental setup.

The performance of the vehicular communication-clustering process

For the new wireless systems and beyond, the intelligent transportation system is considered as one of the main features that could be covered in the new research topics. Furthermore, both high-speed data transmission and data processing play a crucial role for these generations. Our work covers two main propositions in order to attain an improvement in such intelligent systems performance. A clustering algorithm is proposed and presented for grouping mobile nodes based on their speeds with some modified head assignments processes. This will be combined with a parallel-processing technique that enhances the QoS. Mainly, this work concerns enhancing the V2V data transmission and the processing speed. Thus, a wavelet processing stage has been imposed to optimize the transmitted power phenomenon. In order to check the validity of such proposition, five main efficiency factors have been investigated; namely complementary cumulative distributions, bit rates, energy efficiency, the lifetime of cluster head and the ordinary nodes reattaching-head average times.

Enhancing the LTE-based intelligent transportation system's performance

Intelligent transportation system is considered as one of the main features of the new generation wireless systems, where both of high speed data transmission and processing play a crucial role. This work presents two propositions in order to attain the performance improvement for both of data transmission and processing speed. Thus, the presented work consists of deriving a clustering algorithm based on a weighting algorithm for the head assignments processes, and emphasizing the parallel-processing technique based on variety wavelet baby functions, respectively. Accordingly, both of the data transmission speed and power will be examined.In order to verify the findings, a simulation has been done and compared with the following clustering algorithms; namely DMAC, PC, DBC, and Lower-ID DCA. This comparison is based on the following factors; namely efficiency factors involved in this investigation; namely complementary cumulative distributions, bit rates, energy efficiency, the cluster head life time and the ordinary nodes reattaching-head average times. The depicted results for the cluster head duration at 20 km/s show a remarkable system stability based on both the clustering overhead, and the cluster head duration. The attained improvements reach the 53% and 88.4% over the DBC work and the Lowest-ID DCA work, respectively.

Estimation of Land Surface Heat Fluxes Based on Landsat 7 ETM+ Data and Field Measurements over the Northern Tibetan Plateau

Land surface heat fluxes consist of the net radiation flux, soil heat flux, sensible heat flux, and latent heat flux. The estimation of these fluxes is essential to the study of energy transfer in land–atmosphere systems. In this paper, Landsat 7 ETM+ SLC-on data were applied to estimate the land surface heat fluxes on the northern Tibetan Plateau using the SEBS (surface energy balance system) model, in combination with the calculation of field measurements at CAMP/Tibet (Coordinated Enhanced Observing Period (CEOP) Asia–Australia Monsoon Project on the Tibetan Plateau) automatic weather stations based on the combinatory method (CM) for comparison. The root mean square errors between the satellite estimations and the CM calculations for the net radiation flux, soil heat flux, sensible heat flux, and latent heat flux were 49.2 W/m2, 46.3 W/m2, 68.2 W/m2, and 54.9 W/m2, respectively. The results reveal that land surface heat fluxes all present significant seasonal variability. Apart from the sensible heat flux, the satellite-estimated net radiation flux, soil heat flux, and latent heat flux exhibited a trend of summer > spring > autumn > winter. In summer, spring, autumn, and winter, respectively, the median values of the net radiation flux (631.8 W/m2, 583.0 W/m2, 404.4 W/m2, 314.3 W/m2), soil heat flux (40.9 W/m2, 37.9 W/m2, 26.1 W/m2, 20.5 W/m2), sensible heat flux (252.7 W/m2, 219.5 W/m2, 221.4 W/m2, 204.8 W/m2), and latent heat flux (320.1 W/m2, 298.3 W/m2, 142.3 W/m2, 75.5 W/m2) exhibited distinct seasonal diversity. From November to April, the in situ sensible heat flux is higher than the latent heat flux; the opposite is true between June and September, leaving May and October as transitional months. For water bodies, alpine meadows and other main underlying surface types, sensible and latent heat flux generally present contrasting and complementary spatial distributions. Due to the 15–60 m resolution of the Landsat 7 ETM+ data, the distribution of land surface heat fluxes can be used as an indicator of complex underlying surface types over the northern Tibetan Plateau.

An ALMA View of Molecular Filaments in the Large Magellanic Cloud. II. An Early Stage of High-mass Star Formation Embedded at Colliding Clouds in N159W-South

Abstract We have conducted ALMA CO isotopes and 1.3 mm continuum observations toward filamentary molecular clouds of the N159W-South region in the Large Magellanic Cloud with an angular resolution of ∼0.″25 (∼0.07 pc). Although the previous lower-resolution (∼1″) ALMA observations revealed that there is a high-mass protostellar object at an intersection of two line-shaped filaments in 13CO with the length scale of ∼10 pc, the spatially resolved observations, in particular, toward the highest column density part traced by the 1.3 mm continuum emission, the N159W-South clump, show complicated hub-filamentary structures. We also discovered that there are multiple protostellar sources with bipolar outflows along the massive filament. The redshifted/blueshifted components of the 13CO emission around the massive filaments/protostars have complementary distributions, which is considered to be possible evidence for a cloud–cloud collision. We propose a new scenario in which the supersonically colliding gas flow triggers the formation of both the massive filament and protostars. This is a modification of the earlier scenario of cloud–cloud collision, by Fukui et al., that postulated the two filamentary clouds occur prior to the high-mass star formation. A recent theoretical study of the shock compression in colliding molecular flows by Inoue et al. demonstrates that the formation of filaments with hub structure is a usual outcome of the collision, lending support for the present scenario. The theory argues that the filaments are formed as dense parts in a shock compressed sheet-like layer, which resembles “an umbrella with pokes.”

Multiply broken power-law densities as survival functions: An alternative to Pareto and lognormal fits

Survival functions defined by multiply broken power-law densities are introduced to model firm-size data sets of four historical censuses reported in Montebruno et al., Physica A 523 (2019) 858. The survival functions (complementary cumulative distributions) are obtained by least-squares regression. The probability distributions are inferred from the analytic survival functions. The mean firm growth, the growth volatility and entropy evolution are calculated over a 30-year period covered by the censuses. A representation of the survival functions as single power-law density with varying exponent depending on firm size is derived. Index functions (i.e. rescaled logarithmic derivatives of survival functions) are used to demonstrate that neither Pareto power laws nor lognormal densities can accurately reproduce the tails of the firm-size distributions. Like the survival functions, the empirical rank–size relations of the four censuses also admit representation by broken power-law densities. A generating mechanism for empirically obtained broken power-law densities, based on the Fokker–Planck equation, is proposed as well.

Three divisions of the mouse caudal striatum differ in the proportions of dopamine D1 and D2 receptor-expressing cells, distribution of dopaminergic axons, and composition of cholinergic and GABAergic interneurons

The greater part of the striatum is composed of striosomes and matrix compartments, but we recently demonstrated the presence of a region that has a distinct structural organization in the ventral half of the mouse caudal striatum (Miyamoto et al. in Brain Struct Funct 223:4275–4291, 2018). This region, termed the tri-laminar part based upon its differential immunoreactivities for substance P and enkephalin, consists of medial, intermediate, and lateral divisions. In this study, we quantitatively analyzed the distributions of both projection neurons and interneurons in each division using immunohistochemistry. Two types of projection neurons expressing either the dopamine D1 receptor (D1R) or D2 receptor (D2R) showed complementary distributions throughout the tri-laminar part, but the proportions significantly differed among the three divisions. The proportion of D1R-expressing neurons in the medial, intermediate, and lateral divisions was 88.6 ± 8.2% (651 cells from 3 mice), 14.7 ± 3.8% (1025 cells), and 49.3 ± 4.5% (873 cells), respectively. The intermediate division was further characterized by poor innervation of tyrosine hydroxylase immunoreactive axons. The numerical density of choline acetyltransferase immunoreactive neurons differed among the three divisions following the order from the medial to lateral divisions. In contrast, PV-positive somata were distributed throughout all three divisions at a constant density. Two types of GABAergic interneurons labeled for nitric oxide synthase and calretinin showed the highest cell density in the medial division. The present results characterize the three divisions of the mouse caudal striatum as distinct structures, which will facilitate studies of novel functional loops in the basal ganglia.

Analysis of molecular orientation in polymeric spherulite using polarized micro attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging

Micro ATR-FTIR spectroscopic imaging enables the visualization of two-dimensional chemical distribution at a higher spatial resolution than macro-transmission FTIR imaging approach. In this study, micro ATR-FTIR imaging was applied for analysis of a specific morphology in a spherulite of poly(3-hydroxybutyrate) (PHB). The PHB spherulites crystallized at an isothermal condition, showed the fine band structure due to the twisting lamellar crystals during the spherulite growth under the polarized optical microscope (POM). In addition, the band structure observed in the PHB spherulite was the double band pattern in which the higher and lower birefringence banded areas alternatively appear due to the three-dimensional orientation of crystallographic axes and the biaxial refractive index ellipsoid of PHB crystalline structure. Micro ATR-FTIR spectroscopic imaging was employed for detecting the double band structure in the PHB spherulite. However, the obtained spectral images did not indicate any band structures.To detect the difference of molecular orientation among the double band structures, the micro ATR-FTIR imaging was performed with a linear polarizer at four different angles.The mean values of absorbance in each measured area changed depending on the polarizer angle. The in-plane molecular orientation to the tangential direction of spherulite, caused by the dependence of the average absorbance on the polarizer angles, was determined by the position of measured area in the spherulite and the linear dicroism of each of the spectral band used. To visualize the small difference of molecular orientation in the double band structure, micro ATR-FTIR images of the dichroic differences at three spectral bands were calculated from two different sets of polarizer angles. The micro ATR-FTIR images representing the dichroic differences displayed their corresponding distributions among three spectral bands. The complementary distributions of the dichroic difference were caused by the crystallographic orientation of b- and c-axes and were successfully visualized to reveal the pattern with the features less than 10 μm in size. The results achieved in this study were due to two advantages of the polarized micro ATR-FTIR imaging: the high spatial resolution of micro ATR-FTIR imaging technique, and the high sensitivity of polarization measurements. Thus, this work demonstrates the power of this spectroscopic approach for such analytical investigation.

Formation of the Active Star-forming Region LHA 120-N 44 Triggered by Tidally Driven Colliding H i Flows

Abstract The second most active site of high-mass star formation next to R136 in the Large Magellanic Cloud (LMC) is N44. We carried out a detailed analysis of H i at 60″ resolution by using the ATCA and Parkes data. We presented decomposition of the H i emission into two velocity components (the L and D components) with a velocity separation of ∼60 km s−1. In addition, we newly defined the I component whose velocity is intermediate between the L and D components. The D component was used to derive the rotation curve of the LMC disk, which is consistent with the stellar rotation curve. Toward the active cluster-forming region of LHA 120-N 44, the three velocity components of H i gas show signatures of dynamical interaction, including bridges and complementary spatial distributions. We hypothesize that the L and D components have been colliding with each other since 5 Myr ago, and the interaction triggered formation of the O and early-B stars ionizing N44. In the hypothesis, the I component is interpreted as decelerated gas in terms of momentum exchange in the collisional interaction of the L and D components. In the N44 region, the Planck submillimeter dust optical depth is correlated with the H i intensity, which is well approximated by a linear regression. We found that the N44 region shows a significantly steeper regression line than in the bar region, indicating less dust abundance in the N44 region, which is ascribed to the tidal interaction between the LMC and the SMC 0.2 Gyr ago.

Conjugate relay zones: geometry of displacement transfer between opposed-dipping normal faults

Overlapping opposed-dipping normal faults can have complementary displacement distributions, indicating transfer of displacement between them in the same way as at relay zones between faults with the same dip direction. We constrain the mechanism by which displacement is transferred between opposed-dipping faults by examining the geometries of faulted horizons and fault throw distributions at these conjugate relay zones.Structure contour maps of horizons offset by overlapping opposed-dipping faults from different extensional settings display a consistent pattern. Above the line of intersection between the conjugate faults the deformed horizon is flat between converging faults and displacement transfer is reflected in changes in footwall elevation. Below the line of fault intersection the mutual footwall is flat and elevation changes occur in the hanging walls of the divergent faults. These elevation changes can be explained as a simple superposition of the deformation fields of two faults that have retarded lateral propagation due to the presence of the other synchronous fault, irrespective of whether the two faults actually intersect. The observed patterns of horizon elevation strongly resemble those seen at boundaries between adjacent basin-scale half-graben of opposed polarity.

A New Class of Beta-Complementary Exponential Power Series Distributions

Abstract In this paper, we introduce a new class of beta-complementary exponential power series distributions, which is obtained by replacing the cumulative distribution function of the complementary exponential power series distributions in the logit of a beta random variable. This new class of distributions contains some new submodels, such as beta-complementary exponential geometric, beta-complementary exponential Poisson, beta-complementary exponential binomial, beta-complementary exponential logarithmic, and complementary exponential power series distributions. A general class of distributions is presented and some various properties are obtained in this paper. We characterize the beta-complementary exponential geometric distribution as one of the most applicable distributions in this class. Some mathematical properties of the beta-complementary exponential geometric distribution are reached in terms of the corresponding properties of the complementary exponential geometric and beta exponential distributions. We present expressions for the probability density function, cumulative distribution function, moment generating function, and moments. The estimation of parameters is approached by the maximum likelihood estimation procedure, and the expected information matrix is derived. The flexibility of the distribution is illustrated in application of a real data set.

Joint transform correlator-based optical cryptosystem with innovative arrangement of input

Speckle noise is a common issue in optical encryption domain. In this paper, by introducing two complementary checkerboard distributions, we demonstrate an innovative arrangement of input to reduce speckle noise in joint transform correlator (JTC)-based optical cryptosystem. No increase of hardware and complexity in the optical implementation of our proposal. The proposal can effectively improve the quality of reconstructed object and take full advantage of space in input plane. Furthermore, our proposal makes it possible to achieve level-to-level administration of keys, which can be used to implement multiuser authentication in practical application.

Biogeography and early emergence of the genusDidelphis(Didelphimorphia, Mammalia)

AbstractThe genusDidelphiscomprises six species of relatively large‐sized New World marsupials ranging from Argentina to Canada. Most of the diversity of the genus occurs in the Neotropical region, where two groups of species are currently recognized: theDidelphis marsupialisgroup, includingD. marsupialisandD. aurita,and theD. albiventrisgroup comprisingD. albiventris,D. imperfectaandD. pernigra. The genus also includesD. virginiana,the only livingDidelphisspecies reaching the Nearctic region.Didelphis'wide latitudinal distribution, wide range of environments in which it can be found as well as the disjunct, and spatially complementary distributions shown by its species raise some questions regarding the historical biogeography of the genus and how it relates to the geological and climatic events of the Plio‐Pleistocene. The present study is aimed at answering biogeographic and historical questions concerning the evolution ofDidelphis.We employed molecular methods to infer a multi‐locus time‐calibrated phylogeny including allDidelphisspecies which served as a framework for biogeographic analyses. Our results suggest that the basalmost divergence inDidelphisis an event older than previously thought, probably having taken place at some point betweenca.4.3 and 7.4 Mya following a vicariant event. Our results also suggest a northern South American origin for the genus, and that it possibly expanded its range to North America before the GABI. Climatic‐driven modifications in Neotropical environments during the late Pliocene and early Pleistocene favored the dispersion to new ecosystems triggering the emergence of new lineages.

Cell aggregation in monolayer culture: Clues to a universal kinetics

Aggregation of animal cells in culture comprises a series of motility, collision and adhesion processes of basic relevance for tissue engineering, bioseparations, oncology research and in vitro drug testing. In the present paper, we characterize the aggregation kinetics of normal and cancer cells in culture by determining their cluster size distribution functions. Our experiments reveal that the complementary cumulative distributions for eight cell lines from epithelial and mesenchymal origins are described by stretched exponential functions. Also, we find that as time evolves and the cell density increases, a dynamical phase transition occurs from an aggregation regime described by monotonically decreasing cluster size distributions to another one in which these distributions are nonmonotonic, exhibiting local maxima at large cluster sizes. Subtly, the universality of the stretched exponential distributions admits distinct cluster growth processes controlled by motility and adhesion traits of the cells.

Families of complementary distributions

Each continuous distribution on (0,1), with cumulative distribution function F say, has a complementary distribution which is the distribution with cumulative distribution function F−1. Some basic general properties of complementary distributions are given.A particular focus of this article is then the construction of families of distributions, each based on a given F and indexed by a single additional parameter, which are closed under complementarity; properties of these families of distributions are explored, as are those of a particular special case.

A New Look at the Molecular Gas in M42 and M43: Possible Evidence for Cloud–Cloud Collision that Triggered Formation of the OB Stars in the Orion Nebula Cluster

Abstract The Orion Nebula Cluster toward the H ii region M42 is the most outstanding young cluster at the smallest distance (410 pc) among the rich high-mass stellar clusters. By newly analyzing the archival molecular data of the 12CO(J = 1–0) emission at 21″ resolution, we identified at least three pairs of complementary distributions between two velocity components at 8 and 13 km s−1. We present a hypothesis that the two clouds collided with each other and triggered formation of the high-mass stars, mainly toward two regions including the nearly 10 O stars in M42 and the B star, NU Ori, in M43. The timescale of the collision is estimated to be ∼0.1 Myr by a ratio of the cloud size and velocity corrected for projection, which is consistent with the age of the youngest cluster members less than 0.1 Myr. The majority of the low-mass cluster members were formed prior to the collision in the last Myr. We discuss the implications of the present hypothesis and the scenario of high-mass star formation by comparing with the other eight cases of triggered O-star formation via cloud–cloud collision.

Large-scale CO J = 1–0 observations of the giant molecular cloud associated with the infrared ring N35 with the Nobeyama 45 m telescope

Abstract We report an observational study of the giant molecular cloud (GMC) associated with the Galactic infrared ring-like structure N35 and two nearby H ii regions G024.392+00.072 (H ii region A) and G024.510−00.060 (H ii region B), using the new CO J = 1–0 data obtained as a part of the FOREST Unbiased Galactic Plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) project at a spatial resolution of 21″. Our CO data reveals that the GMC, with a total molecular mass of 2.1 × 106 M⊙, has two velocity components of over ∼10–15 km s−1. The majority of molecular gas in the GMC is included in the lower-velocity component (LVC) at ∼110–114 km s−1, while the higher-velocity components (HVCs) at ∼118–126 km s−1 consist of three smaller molecular clouds which are located near the three H ii regions. The LVC and HVCs show spatially complementary distributions along the line-of-sight, despite large velocity separations of ∼5–15 km s−1, and are connected in velocity by the CO emission with intermediate intensities. By comparing the observations with simulations, we discuss a scenario where collisions of the three HVCs with the LVC at velocities of ∼10–15 km s−1 can provide an interpretation of these two observational signatures. The intermediate-velocity features between the LVC and HVCs can be understood as broad bridge features, which indicate the turbulent motion of the gas at the collision interfaces, while the spatially complementary distributions represent the cavities created in the LVC by the HVCs through the collisions. Our model indicates that the three H ii regions were formed after the onset of the collisions, and it is therefore suggested that the high-mass star formation in the GMC was triggered by the collisions.