Circular Cluster Research Articles

Identification of Mosaic Order Area of Geometric Triangular Chiral Hexagonal Complexes in Interphase with Morphology Biosignature Pattern in the Interior of Martian Nested Impact Craters

From evolutionary miniaturization activation of ancestral larger genes stocks, an electromagnetic field derivate from cancer microscopic collision events participates in the elaboration of geometric complexes and chiral biomolecules that serve to build bodies with embryoid print as it develops during gestation. This miniaturization platform literally allows us to see what would otherwise remain completely invisible. In concordance with our observations collision extreme chaos generates in space time interval geometric scalable invariant extreme order. To determine whether our predictions are valid, we select Mars one of the planets with highest rate collision impact craters. The idea that impact events produce major geological effects that go far beyond the production of craters has recently been emphasized. We wonder if we could predict geometric chiral triangular hexagonal complexes in Martian landscape similar to those documented at microscopic, macroscopic, megascopic levels. We resolved to investigate the geomorphology patterns of more than 4000 collision impact craters in Mars landscape using images from Google Mars platforms, and HIRISE (High resolution imaging science experiment camera from the University of Arizona) based on a pattern recognition images algorithm we identified Mars mosaic order area (MOA). MOA is a circular cluster of overlap craters organized in apparent visible cycle sequential order oriented counterclockwise and consisting of nine craters that structure visible and measurable geometry in interface with biosignature morphologies in their interior not having been previously documented. Crater, therefore, is a step forward in understanding how collisions influence life, both on Earth and on other planets. We were pleased that the correctly pattern image algorithm predicted the identification of irreducible geometry matrix of GTCHC complexes in Martian impact craters. Cancer can inform astrobiology.

Effects of zonal harmonics and a circular cluster of material points on the stability of triangular equilibrium points in the R3BP

We have studied a modified version of the classical restricted three-body problem (CR3BP) where both primaries are considered as oblate spheroids and are surrounded by a homogeneous circular planar cluster of material points centered at the mass center of the system. In this dynamical model we have examined the effects of oblateness of both primaries up to zonal harmonic J 4; together with gravitational potential from the circular cluster of material points on the existence and linear stability of the triangular equilibrium points. It is found that, the triangular points are stable for 0<μ<μ c and unstable for $\mu_{c} \le \mu \le \frac{1}{2}$ , where μ c is the critical mass ratio affected by the oblateness up to J 4 of the primaries and potential from the circular cluster of material points. The coefficient J 4 has stabilizing tendency, while J 2 and the potential from the circular cluster of material points have destabilizing tendency. A practical application of this model could be the study of the motion of a dust particle near oblate bodies surrounded by a circular cluster of material points.

Stability of equilibrium points in a CR3BP with oblate bodies enclosed by a circular cluster of material points

We have investigated an improved version of the classic restricted three-body problem where both primaries are considered oblate and are enclosed by a homogeneous circular planar cluster of material points centered at the mass center of the system. In this dynamical model we have examined the effect on the number and on the linear stability of the equilibrium locations of the small particle due to both, the primaries’ oblateness and the potential created by the circular cluster. We have drawn the zero-velocity surfaces and we have found that in addition to the usual five Lagrangian equilibrium points of the classic restricted three-body problem, there exist two new collinear points L n1,L n2 due to the potential from the circular cluster of material points. Numerical investigations reveal that with the increase in the mass of the circular cluster of material points, L n2 comes nearer to the more massive primary, while L n1 moves away from it. Owing to oblateness of the bodies, L n1 comes nearer to the more massive primary, while L n2 moves towards the less massive primary. The collinear equilibrium points remain unstable, while the triangular points are stable for 0<μ<μ c and unstable for $\mu_{c} \le \mu \le \frac{1}{2}$ , where μ c is the critical mass ratio influenced by oblateness of the primaries and the potential from the circular cluster of material points. The oblateness and the circular cluster of material points have destabilizing tendency.

Comprehensive Evaluation on the Development of Industry Cluster Circular Economy

In allusion to the issues for further evaluation research into the circular economy development on the industrial cluster level, the paper constructs a comprehensive evaluation index system for circular economy, combined with industrial cluster’s own characteristics. And this paper determines the index weight based on comprehensive weighted method that combines objective information entropy and subjective AHP method, and then builds a comprehensive evaluation model of circular economy industry cluster development.

Spatial and temporal epidemiology of bovine trichomoniasis and bovine genital campylobacteriosis in La Pampa province (Argentina)

The venereal diseases bovine trichomoniasis (BT) and bovine genital campylobacteriosis (BCG) cause economic losses in endemic areas like La Pampa province in Argentina, where beef cattle are usually managed extensively. This study used data compiled under a Provincial Programme for the Control and Eradication of BT and BGC (PCE) to determine the spatio-temporal distribution of these diseases and identify spatial clusters. The study population comprised 29,178 non-virgin bulls drawn from 3766 herds, tested for BT and BGC in 2010. Preputial smegma samples were cultured for BT detection, while BGC was diagnosed by direct immunofluorescence testing of these samples. Campylobacter fetus infection was detected in 1.5% of bulls and 2.3% of herds, and Tritrichomonas foetus infection was found in 1.1% of bulls and 5.1% of herds. The proportion of positive tests was highest in February for BT, while in April it was highest for BCG, and was inversely related to the number of tests, which was greatest during the breeding season (spring). An elliptical spatial cluster of high risk for BGC and a circular cluster for BT were both identified in the south of La Pampa province, which could not be explained by cattle herd density. The spatial and temporal patterns identified in this study provide baseline data for monitoring the success of BT and BGC control activities in La Pampa.

Triangular rogue wave cascades

By numerically applying the recursive Darboux transformation technique, we study high-order rational solutions of the nonlinear Schrödinger equation that appear spatiotemporally as triangular arrays of Peregrine solitons. These can be considered as rogue wave cascades and complement previously discovered circular cluster forms. In this analysis, we reveal a general parametric restriction for their existence and investigate the interplay between cascade and cluster forms. As a result, we demonstrate how to generate many more hybrid rogue wave solutions, including semicircular clusters that resemble claws.

Stability and minimum size of colloidal clusters on a liquid-air interface

A vertical force applied to each of two colloids, trapped at a liquid-air interface, induces their logarithmic pairwise attraction. I recently showed [Phys. Rev. E 79, 011407 (2009)] that in clusters of size R much larger than the capillary length λ, the attraction changes to that of a power law and is much stronger due to a many-body effect, and I derived two equations that describe the equilibrium coarse-grained meniscus profile and colloid density in such clusters. In this paper, this theory is shown also to describe small clusters with R≪ λ provided the number N of colloids therein is sufficiently large. An analytical solution for a small circular cluster with an arbitrary short-range power-law pairwise repulsion is found. The energy of a cluster is obtained as a function of its radius R and colloid number N. As in large clusters, the attraction force and energy universally scale with the distance L between colloids as L(-3) and L(-2), respectively, for any repulsion forces. The states of an equilibrium cluster, predicted by the theory, are shown to be stable with respect to small perturbations of the meniscus profile and colloid density. The minimum number of colloids in a circular cluster, which sustains the thermal motion, is estimated. For standard parameters, it can be very modest, e.g., in the range 20-200, which is in line with experimental findings on reversible clusterization on a liquid-air interface.

How small can an equilibrium colloidal cluster on a liquid-air interface be?

A vertical force on a pair of spherical colloids trapped at a liquid-air interface induces their logarithmic pairwise attraction. However, in clusters of size R much larger than the capillary length λ, the many-body interaction dramatically changes the capillary attraction: it is much stronger and no longer logarithmic [V. M. Pergamenshchik, Phys. Rev. E 79, 011407 (2009)]. In this paper, this theory is shown to describe also small clusters with R ≪ λ if they consist of sufficiently large numbers of colloids. The analytical solution for a small circular cluster with a short range powerlaw repulsion with arbitrary exponent n is found. Irrespective of n, the attraction force and the energy scale with the distance L between colloids as L−3 and L−2 for clusters of any size. We estimate the minimum size of a cluster in which the predicted many-body capillary attraction can prevent evaporation of colloids due to their thermal motion. For standard parameters, the minimum number of colloids in a stable nonevaporating cluster can be as low as 20–200. These numbers are in accord with the experimental findings on reversible clusterization on a liquid-air interface.

Complete Genome Sequence of Carnobacterium sp. 17-4

Members of the carnobacteria have been extensively studied as probiotic cultures in aquacultures and protective cultures in seafood, diary, and meat. We report on the finished genome sequence of Carnobacterium sp. 17-4, which has been isolated from permanently cold seawater. The genetic information reveals a new circular bacteriocin biosynthesis cluster.

Hexaploid H1 (ES) cells established from octaploid H1 cells are as DNA stable as pentaploid H1 cells

Hexaploid H1 (ES) cells (6H1 cells) were established from octaploid H1 cells (8H1 cells), as were pentaploid H1 cells (5H1 cells). 6H1 cells were compared with 5H1 cells. The number of chromosomes of 6H1 cells was 115, 20 more than the 95 of 5H1 cells. The durations of G(1), S, and G(2)/M phases of 6H1 cells were 3, 7, and 6 h, respectively, almost the same as those of 5H1 cells. The cell volume of 6H1 cells was equivalent that of 5H1 cells. The morphology of 6H1 cells was flattened circular cluster, different from the spherical cluster of 5H1 cells. 6H1 cells exhibited alkaline phosphatase activity as well as 5H1 cells. The DNA content of 6H1 cells was stable and maintained for 300 days of culturing, the same as that of 5H1 cells. The DNA stability of 6H1 cells was explained using a hypothesis concerning the DNA structure of polyploid cells because the asymmetric configuration of homologous chromosomes in 6H1 cells inhibited chromosome loss.

Acoustic scattering by a cluster of small sound-soft obstacles

The scattering problem of an incident plane sound wave by a finite number of small sound-soft arbitrarily shaped obstacles is considered. First, we study the case of multiple scattering in the long wave limit. By analogy with Greenwood's approximation for the electrical constriction resistance of a circular cluster of microcontacts, we obtain an approximation for the harmonic capacity of a system of a large number of small sound-soft obstacles grouped into a spherical cluster. We generalize Greenwood's approach for the case of an arbitrary convex cluster and, as a by-product of our analysis, we elicit an approximate formula for the harmonic capacity of a convex solid. The study of the general case of multiple scattering by a cluster of small soft-sound obstacles is based on the first order asymptotic model obtained in our previous paper. We use the method of artificial small parameter for constructing Padé approximants of the scattering amplitude. Explicit formulas are derived and illustrated on several examples.

On the nature and origin of the oxalate package in Solanum sisymbriifolium anthers

This is a detailed study carried out in Solanum sisymbriifolium Lam. on the development of the circular cell cluster (CCC) during crystal deposition, as well as the composition of the crystals. Light microscopy and scanning and transmission electron microscopy (TEM) were used to characterize tissue throughout anther development. Energy dispersive X-ray analysis (EDAX) allowed the determination of the elemental composition of crystals that form in the CCC region, and infrared and x-ray diffraction analysis were used to specify the crystal salt composition. TEM analysis revealed that the crystals originated simultaneously within the vacuoles in association with a paracrystalline protein. Prior to the appearance of protein within vacuoles, protein paracrystals were visible in both rough endoplasmic reticulum and vesicles with ribosomes on their membranes. In vacuoles, paracrystals constitute nucleation sites for druse crystals formation. EDAX revealed that C, O, and Ca were the main elements, and K, Cl, Mg, P, S, and Si, the minor elements. X-ray powder diffraction of crystals detected the predominant presence of calcium oxalate, but also vestiges of calcite, quartz, and sylvite. The calcium oxalate coexisted in the three chemical forms, that is, whewellite, weddellite, and caoxite. Infrared spectrophotometry identified bands that characterize O-C-O, H-O, C-H bonds, all of calcium oxalate, and Si-O-Si, of quartz. These results were compared with studies of anthers carried out in other Solanaceae genera.

Epidemiology and control of frontier malaria in Brazil: lessons from community-based studies in rural Amazonia

We describe the epidemiology of malaria in a frontier agricultural settlement in Brazilian Amazonia. We analysed the incidence of slide-confirmed symptomatic infections diagnosed between 2001 and 2006 in a cohort of 531 individuals (2281.53 person-years of follow-up) and parasite prevalence data derived from four cross-sectional surveys. Overall, the incidence rates of Plasmodium vivax and P. falciparum were 20.6/100 and 6.8/100 person-years at risk, respectively, with a marked decline in the incidence of both species (81.4 and 56.8%, respectively) observed between 2001 and 2006. PCR revealed 5.4-fold more infections than conventional microscopy in population-wide cross-sectional surveys carried out between 2004 and 2006 (average prevalence, 11.3 vs. 2.0%). Only 27.2% of PCR-positive (but 73.3% of slide-positive) individuals had symptoms when enrolled, indicating that asymptomatic carriage of low-grade parasitaemias is a common phenomenon in frontier settlements. A circular cluster comprising 22.3% of the households, all situated in the area of most recent occupation, comprised 69.1% of all malaria infections diagnosed during the follow-up, with malaria incidence decreasing exponentially with distance from the cluster centre. By targeting one-quarter of the households, with selective indoor spraying or other house-protection measures, malaria incidence could be reduced by more than two-thirds in this community.

A power comparison of generalized additive models and the spatial scan statistic in a case-control setting

BackgroundA common, important problem in spatial epidemiology is measuring and identifying variation in disease risk across a study region. In application of statistical methods, the problem has two parts. First, spatial variation in risk must be detected across the study region and, second, areas of increased or decreased risk must be correctly identified. The location of such areas may give clues to environmental sources of exposure and disease etiology. One statistical method applicable in spatial epidemiologic settings is a generalized additive model (GAM) which can be applied with a bivariate LOESS smoother to account for geographic location as a possible predictor of disease status. A natural hypothesis when applying this method is whether residential location of subjects is associated with the outcome, i.e. is the smoothing term necessary? Permutation tests are a reasonable hypothesis testing method and provide adequate power under a simple alternative hypothesis. These tests have yet to be compared to other spatial statistics.ResultsThis research uses simulated point data generated under three alternative hypotheses to evaluate the properties of the permutation methods and compare them to the popular spatial scan statistic in a case-control setting. Case 1 was a single circular cluster centered in a circular study region. The spatial scan statistic had the highest power though the GAM method estimates did not fall far behind. Case 2 was a single point source located at the center of a circular cluster and Case 3 was a line source at the center of the horizontal axis of a square study region. Each had linearly decreasing logodds with distance from the point. The GAM methods outperformed the scan statistic in Cases 2 and 3. Comparing sensitivity, measured as the proportion of the exposure source correctly identified as high or low risk, the GAM methods outperformed the scan statistic in all three Cases.ConclusionsThe GAM permutation testing methods provide a regression-based alternative to the spatial scan statistic. Across all hypotheses examined in this research, the GAM methods had competing or greater power estimates and sensitivities exceeding that of the spatial scan statistic.

Cluster Analysis of Mortality in an Area of Campania Region (Italy), with Intense Environmental Pressure due to Waste

ISEE-0818 Background and Objective: Different health effects have been repeatedly associated with residence close to waste landfill sites. The Campania region experienced a long period waste crisis including widespread illegal practice of dumping toxic and urban waste. In that area, statistically significant clusters of mortality by lung, liver, gastric, kidney and bladder cancers and of selected congenital malformations have been reported (Fazzo et al. 2008); many of these outcomes resulted spatially correlated with an intensity index of waste-related exposure (Martuzzi et al. 2009). The objective is to investigate whether non-cancer mortality causes show a tendency for clustering in the waste dumping areas. Methods: Cluster analyses of causes of death (ICD-9) were performed for diabetes (250), circulatory (390–459), myocardial infarction (410–414), cerebrovascular (430–438), respiratory (460–519), digestive (520–579), cirrhosis (571), urogenital (580–629). The unit of the study consists of the 196 municipalities of the Provinces of Naples and Caserta. Mortality data were retrieved from the Italian National Institute of Statistics for 1994–2001. Cluster analysis by Spatial Scan Statistics using 5 km maximum radius of circular cluster was performed. The population resident in the provinces of Naples and Caserta, excluding Naples, was used as standard. For each gender SMR was standardized for age and deprivation index. Results: Among 15 statistically significant most likely clusters emerged, 11 included sub-areas at higher waste risk: mortality due to diabetes, circulatory, myocardial infarction, cerebrovascular diseases for men and women, respiratory for women, digestive and cirrhosis for men. The observed/expected ratio ranged from 1.2 for myocardial infarction in men and women to 2.9 for cerebrovascular causes in women. Conclusion: The clustering results indicate associations between some non-cancer mortality causes and residence in waste disposal areas similar to those described for cancer mortality. Many other risk factors can play a role and ad-hoc analytical studies need to be carried out.

Sound scattering by anisotropic metafluids based on two-dimensional sonic crystals

Multiple-scattering theory is here employed to study the scattering of sound by a fluidlike cylinder characterized by an anisotropic mass density tensor. A derivation of the $t$ matrix associated to such acoustic material nonexisting in nature is here comprehensively derived, and the result is employed to study the pressure field produced by plane sound waves impinging the cylinder. It is also shown that an acoustic metamaterial or metafluid can be engineered to exactly match the dynamical properties of the anisotropic fluid by using a circular cluster made of a two-dimensional sonic crystal with a nonisotropic lattice.

Strong collective attraction in colloidal clusters on a liquid-air interface

It is shown that in a cluster of many colloids, trapped at a liquid-air interface, the well-known vertical-force-induced pairwise logarithmic attraction changes to a strongly enhanced power-law attraction. In large two-dimensional clusters, the attraction energy scales as the inverse square of the distance between colloids. The enhancement is given by the ratio eta = (square of the capillary length) / (interface surface area per colloid) and can be as large as 10;{5} . This explains why a very small vertical force on colloids, which is too weak to bring two of them together, can stabilize many-body structures on a liquid-air interface. The profile of a cluster is shown to consist of a large slow collective envelope modulated by a fast low-amplitude perturbation due to individual colloids. A closed equation for the slow envelope, which incorporates an arbitrary power-law repulsion between colloids, is derived. For example, this equation is solved for a large circular cluster with the hard-core colloid repulsion. It is suggested that the predicted effect is responsible for mysterious stabilization of colloidal structures observed in experiments on a surface of isotropic liquid and nematic liquid crystal.

Inclusion of heat transfer computations for particle laden flows

A newly developed direct numerical simulation method has been used to study the dynamics of nonisothermal cylindrical particles in particulate flows. The momentum and energy transfer equations are solved to compute the effects of heat transfer in the sedimentation of particles. Among the effects examined is the drag force on nonisothermal particles, which we found strongly depends on the Reynolds and Grashof numbers. It was observed that heat advection between hotter particles and fluid causes the drag coefficient of particles to significantly increase at relatively low Reynolds numbers. For Grashof number of 100, the drag enhancement effect diminishes when the Reynolds number exceeds 50. On the contrary, heat advection with colder particles reduces the drag coefficient for low and medium Reynolds number (Re&amp;lt;50) for Grashof number of −100. We used this numerical method to study the problem of a pair of hot particles settling in a container at different Grashof numbers. In isothermal cases, such a pair of particles would undergo the well-known drafting-kissing-tumbling (DKT) motion. However, it was observed that the buoyancy currents induced by the hotter particles reverse the DKT motion of the particles or suppress it altogether. Finally, the sedimentation of a circular cluster of 172 particles in an enclosure at two different Grashof numbers was studied and the main features of the results are presented.

A flexibly shaped spatial scan statistic for detecting clusters

BackgroundThe spatial scan statistic proposed by Kulldorff has been applied to a wide variety of epidemiological studies for cluster detection. This scan statistic, however, uses a circular window to define the potential cluster areas and thus has difficulty in correctly detecting actual noncircular clusters. A recent proposal by Duczmal and Assunção for detecting noncircular clusters is shown to detect a cluster of very irregular shape that is much larger than the true cluster in our experiences.MethodsWe propose a flexibly shaped spatial scan statistic that can detect irregular shaped clusters within relatively small neighborhoods of each region. The performance of the proposed spatial scan statistic is compared to that of Kulldorff's circular spatial scan statistic with Monte Carlo simulation by considering several circular and noncircular hot-spot cluster models. For comparison, we also propose a new bivariate power distribution classified by the number of regions detected as the most likely cluster and the number of hot-spot regions included in the most likely cluster.ResultsThe circular spatial scan statistics shows a high level of accuracy in detecting circular clusters exactly. The proposed spatial scan statistic is shown to have good usual powers plus the ability to detect the noncircular hot-spot clusters more accurately than the circular one.ConclusionThe proposed spatial scan statistic is shown to work well for small to moderate cluster size, up to say 30. For larger cluster sizes, the method is not practically feasible and a more efficient algorithm is needed.

Differentiation and degeneration of cells that play a major role in tobacco anther dehiscence

Dehiscence is the terminal step in anther development that releases pollen grains from the wall of each theca at a specific site between the two locules. In tobacco, two groups of cells—the circular cell cluster and the stomium—are required for anther dehiscence and define the position at which pollen is released. The processes responsible for the differentiation of the circular cell cluster and the stomium from cells in specific anther regions are unknown. Nor is it understood what initiates the programmed degeneration of these cell types that ultimately is responsible for pollen release from the anther. We characterized stomium and circular cell cluster differentiation and degeneration using both light and transmission electron microscopy throughout anther development, from the emergence of stamen primordia to anther dehiscence at flower opening. We observed that histological changes within primordium L1 and L2 cells destined to become the stomium and circular cell cluster occur at the same time after the differentiation of surrounding locule regions. Sub-epidermal cells that differentiate into the circular cell cluster divide, enlarge, and generate vacuoles with calcium oxalate crystals prior to any detectable changes in pre-stomium epidermal cells. Differentiation and division of cells that generate the stomium occur after cell degeneration initiates in the circular cell cluster. Prior to dehiscence, the stomium consists of a small set of cytoplasmically dense cells that are easily distinguished from their larger, highly vacuolate epidermal neighbors. Plasmodesmata connections within and between cells of the stomium and circular cell cluster were observed at different developmental stages, suggesting that these cells communicate with each other. Circular cell cluster and stomium cell death is programmed developmentally and occurs at different times. Degeneration of the circular cell cluster occurs first, contributes to the formation of a bilocular anther, and generates the site of anther wall breakage. The stomium cell death process is complete at flower opening and provides an opening for pollen release from each theca. We used laser capture microdissection and real-time quantitative reverse-transcription polymerase chain reactions to demonstrate that stomium cells can be isolated from developing anthers and studied for the presence of specific mRNAs. Our data suggest that a cascade of unique gene expression events throughout anther development is required for the dehiscence program, and that the differentiation of the stomium and circular cell cluster in the interlocular region of the anther probably involves cell signaling processes.