Simultaneous Events Research Articles

APiX, a two-tier avalanche pixel sensor for digital charged particle detection

In this paper we present a position-sensitive detector based on the vertical integration of pairs of aligned pixels operating in Geiger-mode regime and designed for charged particle detection. This novel device exploits the coincidence between two simultaneous avalanche events to discriminate between particle-triggered detections and dark counts. This concept allows to have a reduced material budget and low power consumption in spite of a high granularity and fast timing response. A proof-of-principle prototype was designed and fabricated in a 150 nm CMOS process and vertically integrated through bump bonding. This first demonstrator has been characterized and tested with a high energy particle beams at CERN SPS/PS facilities, in different configurations, featuring a reduction of the dark-count rate (DCR) at room temperature from ∼100 kHz/mm2 to about 24 Hz/mm2 a particle detection efficiency limited only by the geometric factor. The device radiation tolerance has been investigated, via irradiation of single tiers with 10 keV X-rays up to a dose of 1 Mrad (SiO2) and with neutrons up to a fluence of 1011 cm−2. A second prototype, addressing the goal to improve the present fill-factor, has been designed, manufactured and approaches now the characterization phase. Potential applications of this sensor include high spatial resolution tracking in high-energy experiments, radiation monitoring in space and radiation imaging in nuclear medicine. A small hand-held demonstrator is under construction for radio-guided surgery.

EVALUACIÓN DEL MECANISMO DE ABSORCIÓN DE ACEITE Y PÉRDIDA DE AGUA DURANTE EL FREIDO DE TORTILLA CHIPS

Simple equation Mt/M∞ = Ktn is evaluated to describe the Fickian mechanism of oil absorption and water release during the frying of tortilla chips in nixtamalized samples with lime and without lime where Mt/M∞ is the fractional solute absorption or release, and n is the diffusional exponent characteristic of the Fickian mechanism that changes with food physical and chemical properties. For the Fickian mechanism, the exponent (n) is ≤0.50, and non-Fickian is 0.5<n<1 for slabs. Moisture releases showed a Fickian mechanism form tortilla chips with lime (n = 0.5) due to water interaction with matrix components and non-Fickian for tortilla chips without lime (n = 0.6). Oil absorption showed a Fickian mechanism for nixtamalization with lime n = 0.4 and for nixtamalization without lime, one of n = 0.3. The larger water diffusion coefficient in the tortilla chip compared to that of oil diffusion indicates that water release and oil absorption during frying is not a simultaneous event. The behavior of the water and oil diffusion is an interesting topic that, in this study, was investigated using a practical equation with potential application in food processing.

Spatio-temporal variability of binary weather patterns and precipitation amounts of short time intervals during winter period over the north-west Himalaya (NWH)

Spatio-temporal variability of binary weather patterns (precipitation event/no-precipitation event) and precipitation amounts of short time intervals of 15, 24, 48 and 72 hours (h) are examined by analysing data on the observed precipitation amount of 3377 common days of different winters (winter 1993–winter 2015) at 12 stations in the north-west Himalaya (NWH). Surface meteorological variables over the NWH are collected daily at 0300 and 1200 UTC and data on the precipitation amount collected daily at 0300 UTC are taken to conduct this study. Data on the precipitation amount collected at 0300 UTC daily represent the cumulative precipitation amount of a short time interval of the previous 15 h (1200–0300 UTC) hence the precipitation amount of the 15 h time interval is considered in addition to the precipitation amounts of 24, 48 and 72 h time intervals to examine the Spatio-temporal variability of the precipitation amounts at 12 stations over the NWH. The spatio-temporal variability in the binary weather patterns of short time intervals is examined by computing the normalised percentage differences in the observed precipitation events of short time intervals at 11 stations from corresponding observed precipitation events at a reference station and Spatio-temporal variability in the precipitation amount of short time interval at 12 stations is examined by computing Mean Absolute Differences (MADs) and Root Mean Square Differences (RMSDs) of observed precipitation amounts of short time intervals at each station from corresponding observed precipitation amounts at a reference station. Normalised percentage difference in precipitation events and MAD (RMSD) of the precipitation amount of 24 h time intervals at 11 stations from a reference station fall in the range (−) 50.0%–(+) 20.7% and 4.2–7.2 mm (12.2–18.5 mm), respectively. The maximum difference in binary weather patterns is found for 24 h time interval and simultaneous precipitation events are not found up to 72 h time interval at 12 stations over the NWH. The spatial variability of binary weather patterns is found to decrease and the spatial variability of the precipitation amount is found to increase with the increasing length of short time intervals, i.e., 15–72 h. These findings show that binary weather patterns and precipitation amounts of short time intervals exhibit large Spatio-temporal variability over the NWH. Results of this study can be useful for various applications directly (or indirectly) influenced by weather and/or precipitation amounts of short time intervals over the NWH during the winter period.

A new species of Physaloptera (Nematoda: Spirurida) from Proechimys gardneri (Rodentia: Echimyidae) from the Amazon rainforest and molecular phylogenetic analyses of the genus.

Nematodes of the genus Physaloptera are globally distributed and more than 100 species are known. Their life cycle involves insects, including beetles, cockroaches and crickets, as intermediate hosts. This study describes a new species of Physaloptera and reports molecular phylogenetic analyses to determine its relationships within the family Physalopteridae. Physaloptera amazonica n. sp. is described from the stomach of the caviomorph rodent Proechimys gardneri collected in the Amazon rainforest in the state of Acre, Brazil. The species is characterized by the male having the first and second pair of sessile papillae asymmetrically placed, lacking a median papilla-like protuberance between the third pairs of sessile papillae, differentiated by size and shape of the spicules, while females have four uterine branches. For both nuclear 18S rRNA and MT-CO1 gene-based phylogenies, we recovered Turgida sequences forming a clade nested within Physaloptera, thus making Physaloptera paraphyletic to the exclusion of Turgida, suggesting that the latter may have evolved from the former monodelphic ancestral state to a derived polydelphic state, or that some species of Physaloptera may belong to different genera. Relationships between most taxa within Physaloptera were poorly resolved in our phylogenies, producing multifurcations or a star phylogeny. The star-like pattern may be attributed to evolutionary processes where past simultaneous species diversification events took place. Physaloptera amazonica n. sp. formed an independent lineage, separately from the other species of Physaloptera, thus supporting the status of a new species. However, all molecular data suggested a closer relationship with other Neotropical species. In conclusion, we added a new species to this already largely diverse genus Physaloptera, bringing new insights to its phylogenetic relationships. Further analyses, adding more species and markers, should provide a better understanding of the evolutionary history of physalopterids.

Large-Scale Frequent Episode Mining from Complex Event Sequences with Hierarchies

Frequent Episode Mining (FEM), which aims at mining frequent sub-sequences from a single long event sequence, is one of the essential building blocks for the sequence mining research field. Existing studies about FEM suffer from unsatisfied scalability when faced with complex sequences as it is an NP-complete problem for testing whether an episode occurs in a sequence. In this article, we propose a scalable, distributed framework to support FEM on “big” event sequences. As a rule of thumb, “big” illustrates an event sequence is either very long or with masses of simultaneous events. Meanwhile, the events in this article are arranged in a predefined hierarchy. It derives some abstractive events that can form episodes that may not directly appear in the input sequence. Specifically, we devise an event-centered and hierarchy-aware partitioning strategy to allocate events from different levels of the hierarchy into local processes. We then present an efficient special-purpose algorithm to improve the local mining performance. We also extend our framework to support maximal and closed episode mining in the context of event hierarchy, and to the best of our knowledge, we are the first attempt to define and discover hierarchy-aware maximal and closed episodes. We implement the proposed framework on Apache Spark and conduct experiments on both synthetic and real-world datasets. Experimental results demonstrate the efficiency and scalability of the proposed approach and show that we can find practical patterns when taking event hierarchies into account.

Pandemic fluoroquinolone resistant Escherichia coli clone ST1193 emerged via simultaneous homologous recombinations in 11 gene loci

Global growth in antibiotic resistance is a major social problem. A high level of resistance to fluoroquinolones requires the concurrent presence of at least 3 mutations in the target proteins-2 in DNA gyrase (GyrA) and 1 in topoisomerase IV (ParC), which occur in a stepwise manner. In the Escherichia coli chromosome, the gyrA and parC loci are positioned about 1 Mb away from each other. Here we show that the 3 fluoroquinolone resistance mutations are tightly associated genetically in naturally occurring strains. In the latest pandemic uropathogenic and multidrug-resistant E. coli clonal group ST1193, the mutant variants of gyrA and parC were acquired not by a typical gradual, stepwise evolution but all at once. This happened as part of 11 simultaneous homologous recombination events involving 2 phylogenetically distant strains of E. coli, from an uropathogenic clonal complex ST14 and fluoroquinolone-resistant ST10. The gene exchanges swapped regions between 0.5 and 139 Kb in length (183 Kb total) spread along 976 Kb of chromosomal DNA around and between gyrA and parC loci. As a result, all 3 fluoroquinolone resistance mutations in GyrA and ParC have simultaneously appeared in ST1193. Based on molecular clock estimates, this potentially happened as recently as <12 y ago. Thus, naturally occurring homologous recombination events between 2 strains can involve numerous chromosomal gene locations simultaneously, resulting in the transfer of distant but tightly associated genetic mutations and emergence of a both highly pathogenic and antibiotic-resistant strain with a rapid global spread capability.

Investigation of left heart flow using a numerical correlation to model heart wall motion

A three-dimensional computational fluid dynamics (CFD) method has been developed to model the flow in the left heart including atrium and ventricle. Since time resolution of the medical scans does not fit the requirements of the CFD calculations, the main challenge in a numerical simulation of heart chambers is wall motion modeling. This study employs a novel three-dimensional approximation scheme to correlate the wall boundary and grid movement in systole and diastole. It uses a geometry extracted from medical images in the literature and deformed based on the reported flow rates. The opening and closing of the mitral (MV) and the aortic valve (AV) considered as simultaneous events. Unstructured tetragonal grids were used for the meshing of the domain. The calculation was performed by a Navier–Stokes solver using the arbitrary Lagrange–Euler (ALE) formulation. Results show that the proposed correlation for the wall motion could predict the main features of heart flows.

Photochemical Reactions of Aminoazobenzene in Solutions, According to Ultrafast Vis Spectroscopy Data

Photoinduced processes (photonics) in trans-aminoazobenzene (t-AAB) are determined by analyzing literature data on transient Vis spectra upon pulsed laser excitation at λex = 400 nm. The analysis is based on the concepts of the rydimer structure of aminoazobenzene dyes, particularly t-AAB2 (the ground state of the dye). It is shown that the photochemical emergence and subsequent transformation of the transient spectra, along with the isomerization of t-AAB2 to cis-aminoazobenzene (c-AAB), are caused by simultaneous events of the splitting of t-AAB2 rydimers into monomers; the splitting of the rydimers is induced by the absorption of visible light by cations of the phenylaminyl type (chromogens of t-AAB2 rydimers). The mechanism of the process is described, which includes the formation of two types of Franck–Condon monomer pairs of t-AAB. As is shown, a pair of one type consists of two identical monomers; it relaxes into the initial t-AAB2 rydimer. A pair of the other type contains one monomer t-AAB and a doubly charged monomer with two cations of the phenylaminyl type and the absorption of visible light in the 500–750 nm range of wavelengths; the monomer dication isomerizes into c-AAB. Structural formulas of the transient electronic configurations are given that explain the photonics of t-AAB2 rydimers.

Patterns of violence and coercion with mental health among female and male trafficking survivors: a latent class analysis with mixture models.

Human trafficking is a crime and a human rights violation that involves various and simultaneous traumatic events (sexual and physical violence, coercion). Yet, it is unknown how the patterning of violence and coercion affects the mental health of female and male trafficking survivors. We conducted a cross-sectional study using a sample of 1015 female and male survivors of trafficking who received post-trafficking assistance services in Cambodia, Thailand or Vietnam. We assessed symptoms of anxiety and depression with the Hopkins Symptoms Checklist and symptoms of post-traumatic stress disorder (PTSD) with the Harvard Trauma Questionnaire. Violence was measured with questions from the World Health Organization International Study on Women's Health. Latent class analysis (LCA) was used to identify distinct patterns of violence and coercion in females and males. Novel multi-step mixture modelling techniques were employed to assess the association of the emergent classes with anxiety, depression and PTSD in females and males. LCA identified two distinct classes of violence and coercion experiences in females (class I: severe sexual and physical violence and coercion (20%); class II: sexual violence and coercion (80%)) and males (class I: severe physical violence and coercion (41%); class II: personal coercion (59%)). Females in class I had a two-fold increase in the odds of anxiety (OR = 2.10; 95% CI: 1.57-2.81) and PTSD (OR = 2.07; 95% CI: 1.03-4.17) compared with females in class II, but differences in the prevalence of anxiety, depression and PTSD were not significant when comparing males in class I to class II. Specific patterns of violence and coercion provide a more in-depth understanding of the role of gender in the experience of violence and coercion and its association with mental health in survivors of trafficking. This information could be useful to target comprehensive mental health services for female and male trafficking survivors.

Linear and nonlinear earthquake location approaches in a case study overview

Several seismic events are calculated by an iterative, linear algorithm relocated in a nonlinear, grid-search with a maximum-likelihood hypocenter method. The same simultaneous events separately registered by regional and local seismological networks have also been used. A verified 1D (one dimensional) velocity crustal structure model is used in both methods and in all datasets for better comparisons. Some rock quarry blasts registered by the local receiver stations as ground truths are examined by both methods. This study's main objectives were: (i) to carry out a comparative examination of the error estimates in both techniques and (ii) to generalize location assessment of the permanent low-density regional network in Central Alborz. The regional network operates under Iranian Seismological Center and its seismic data are massively applied. To reach the research goals, the dataset–method correlation matrix and the location variables were statistically processed. It was shown that the estimated earthquake epicenters by the linear and nonlinear methods are approximately similar for well-located events in each network. For dense-proper distribution of the seismic stations, the elliptical error estimates have lower amounts and consequently the seismicity pattern is more reliable. The difference between subsurface seismicity patterns resulting from the above-mentioned approaches in the studied area is presented. Some depth calculation errors for the same recorded events are higher in the regional network. The correlation comparisons demonstrated that the nonlinear approach and the locally-constrained data may be closer to reality and more convincing. The nonlinear application is more plausible due to all of the possible solutions and less elliptical error estimates under the Gaussian distribution assumption. Subsequently, the combination of the nonlinear method, proper location criteria, and appropriate crustal velocity structure can effectively improve some of the earthquake location estimates in the regional catalogue. As a result, this procedure can be useful in seismicity concept evaluations.

Why the whole is more than the sum of its parts: Salience-driven overestimation in aggregated tactile sensations.

Experimental psychology often studies perception analytically, reducing its focus to minimal sensory units, such as thresholds or just noticeable differences in a single stimulus. Here, in contrast, we examine a synthetic aspect: how multiple inputs to a sensory system are aggregated into an overall percept. Participants in three experiments judged the total stimulus intensity for simultaneous electrical shocks to two digits. We tested whether the integration of component somatosensory stimuli into a total percept occurs automatically, or rather depends on the ability to consciously perceive discrepancy among components (Experiment 1), whether the discrepancy among these components influences sensitivity or/and perceptual bias in judging totals (Experiment 2), and whether the salience of each individual component stimulus affects perception of total intensity (Experiment 3). Perceptual aggregation of two simultaneous component events occurred both when participants could perceptually discriminate the two intensities, and also when they could not. Further, the actual discrepancy between the stimuli modulated both participants' sensitivity and perceptual bias: increasing discrepancies produced a systematic and progressive overestimation of total intensity. The degree of this bias depended primarily on the salience of the stronger stimulus in the pair. Overall, our results suggest that important nonlinear mechanisms contribute to sensory aggregation. The mind aggregates component inputs into a coherent and synthetic perceptual experience in a salience-weighted fashion that is not based on simple summation of inputs.

A reduced-order multiscale model of a free-radical semibatch emulsion polymerization process

Free-radical emulsion polymerization is a heterogeneous process where simultaneous and competitive physicochemical events occur over a wide range of time/length scales. Although a highly accurate representation of the process is possible by multiscale modeling, common approaches face several issues, including the stochastic nature of finer scales, the timely exchange of information between scales, and the high computational load for the model solution. In this work, a reduced-order computationally-tractable multiscale model is proposed while preserving a good predictive capability. The model integrates microscopic-scale calculations based on kinetic Monte Carlo simulations (stochastic), a mesoscopic-scale representation of the particle size distribution through a novel statistical approach and a deterministic description of the macroscopic-scale. The proposed model resulted in faster satisfactory predictions (compared to the model based on the Fokker Planck Equation) of traditional macro and mesoscopic variables, along with the average number of free radicals and secondary nucleation on a microscopic scale.

IL-15-driven clonal expansion of TLR9-primed human B-CLL is characterized by activation of AKT and STAT5, downstream elevation of cyclin D2 and repression of DNA damage response mediators, ATM and TP53BP

Abstract Clonal expansion of B cell chronic lymphocytic leukemia (B-CLL) is linked to mutagenesis and occurs within lymphoid tissues. CpG DNA (ODN-2006) and IL-15, a cytokine found within stromal cells of B-CLL-infiltrated tissues, manifest striking synergy in promoting in vitro growth of B-CLL cells (J Immunol 195:901–923, 2015). Synergy is in part explained by an ODN-induced, NF-kB (p65)-dependent elevation of IL-15Rα and IL-2/15Rβ (CD122) mRNA and protein (J Immunol 201:1570–1585, 2018). Most recently, we examined the downstream consequences of IL-15 signaling through experiments involving intracellular immunofluorescence staining, pharmacologic inhibitors, RT-PCR, and western blotting. Levels of activated pAKTSer473 and pSTAT5Tyr694 were significantly elevated soon after IL-15 exposure to ODN-primed B-CLL cells; furthermore, STAT5 remained activated throughout cycling. Pharmacologic inhibitors of PI-3K or STAT5 blocked IL-15-driven growth, indicating the functional relevance of these pathways. RT-PCR experiments +/− these inhibitors show that IL-15 signaling in B-CLL is characterized by PI-3K &amp; STAT5-dependent rise in cyclin-D2 and repression of two important DNA damage response (DDR) mediators, ATM and TP53BP1, known to dampen growth and facilitate DNA repair. Repression of the latter two proteins was confirmed by western blotting and immunofluorescence studies. We conclude that IL-15 signaling in TLR9-primed B-CLL can provoke a rapid burst in growth via mechanisms resembling those recently described in CD8 T cells. Nonetheless, because dividing B-CLL cells additionally upregulate the mutagenic enzyme, AICDA (Blood 120: 4802–4811, 2012), these simultaneous events may augment B-CLL mutagenesis.

The mode of mitosis is dramatically modified by deletion of a single nuclear pore complex gene in Aspergillus nidulans

Nuclear pore complex (NPC) proteins (Nups) play multiple roles during mitosis. In this study we expand these roles and reveal that in Aspergillus nidulans, compromising the core Nup84-120 subcomplex of the NPC modifies the mitotic behavior of the nuclear envelope (NE). In wildtype cells, the NE undergoes simultaneous double pinching events to separate daughter nuclei during mitotic exit, whereas in Nup84-120 complex mutants, only one restriction of the NE is observed. Investigating the basis for this modified behavior of the NE in Nup deleted cells uncovered previously unrealized roles for core Nups in mitotic exit. During wildtype anaphase, the NE surrounds the two separating daughter DNA masses which typically flank the central nucleolus, to form three distinct nuclear compartments. In contrast, deletion of core Nups frequently results in early nucleolar eviction from the mitotic nucleus, in turn causing an uncharacteristic dumbbell-shaped NE morphology of anaphase nuclei with a nuclear membrane bridge connecting the two forming G1 nuclei. Importantly, the absence of the nucleolus between the separating daughter nuclei during anaphase delays chromosome segregation and progression into G1 as nuclei remain connected by chromatin bridges. Proteins localizing to late segregating chromosome arms are observed between forming daughter nuclei, and the mitotic spindle fails to resolve in a timely manner. These chromatin bridges are occupied by the Aurora kinase until nuclei have fully separated, suggesting involvement of Aurora in monitoring mitotic spindle and nuclear membrane resolution during mitotic exit. Our findings thus reveal a novel requirement for core Nups in mediating nucleolar positioning during mitosis, which dictates the pattern of NE fissions during karyokinesis and facilitates normal chromosome segregation. The findings additionally demonstrate that the mode of mitosis can be dramatically modified by deletion of a single NPC gene and reveals surprising fluidity in mitotic mechanisms.

Optical properties of intracloud and cloud-to-ground discharges derived from JEM-GLIMS lightning observations

We developed a new method to distinguish the lightning discharge type using lightning data obtained by JEM-GLIMS spaced-based mission and ground-based lightning network that are JLDN, NLDN, WWLLN, and GEON. As a first step, we selected 1057 lightning events detected by the JEM-GLIMS cameras (LSI) and spectrophotometers (PH) in 2014. Then, we compared the JEM-GLIMS optical data to the ground-based lightning data in order to check the simultaneous detection of JEM-GLIMS lightning events by the ground-based lightning networks, and finally we identified the discharge type of the JEM-GLIMS lightning events. We succeed in identifying 941 simultaneous lightning events and found that 582, 93, and 266 lightning events were IC, +CG, and -CG discharges, respectively. As a next step, we calculated intensity ratios between blue and red PH channels, i.e., 337nm/762 nm, 316nm/762 nm, 392nm/762 nm, 337nm/(599–900 nm), 316nm/(599–900 nm), and 392nm/(599–900 nm) for the 941 lightning events in order to specify the optical characteristics of IC, +CG, and -CG discharges. It is found that the PH intensity ratio of +CG discharges is the highest and that the PH intensity ratio of IC and -CG discharges is smaller than that of +CG discharge. We also found that the characteristics of the LSI intensity ratio are almost comparable to those of the PH intensity ratio. As the differences of the 337nm/762 nm, 337nm/(599–900 nm), and 392nm/(599–900 nm) ratio of IC, +CG, and -CG discharges are relatively large, these three ratios are a useful proxy for classifying the discharge types for additional 7349 lightning events detected by JEM-GLIMS in order to estimate the global ratio between IC and CG discharges (Z ratio).

TCTAP C-152 Simultaneous Embolic Events in Both Arterial Systems Causing Cardiogenic Shock

### Patient Initials or Identifier Number C.C.J. ### Relevant Clinical History and Physical Exam This was a 37-year-old man who received V-P shunt in his childhood for congenital hydrocephalus. He had no traditional CAD risk factors except smoking. He presented to the emergency department for

Comparison of Two Automatic Identification Algorithms for Cyclones Affecting the Changjiang River–Huaihe River Valleys

In this study, two commonly used automated methods of detecting cyclones in the lower troposphere were compared with respect to various features of cyclone activity. The first method is based on the neighbor cyclone center point (NCP), while the second method is the cyclone area algorithm (CAA), which relies on the detection of the outermost enclosed contour to identify the horizontal structure of a cyclone. We obtained climatologies of cyclones that affected the Changjiang River–Huaihe River Valleys (CHV) of China (derived from ERA-Interim data for 1979–2015) and compared their structures. We found that the distribution of the track and the cyclogenesis locations of influential cyclones (ICs) showed a consistent spatial pattern between the NCP and CAA. However, there were still notable differences between the statistical features of cyclone activity derived by the NCP and CAA: (1) Only &lt;46% of cyclones shared the same cyclone center between these two schemes. (2) ICs derived from the CAA typically had longer lifetimes and travel distances, with stronger central intensities than those from the NCP. (3) The track of ICs by the CAA with high resolution was consistent with that of ICs by the low-resolution CAA as well as the low-resolution NCP. However, compared to other methods, the high-resolution NCP presented large deviations during the early cyclone stage. The involvement of open systems in the NCP resulted in weaker cyclone intensities and increased uncertainty in cyclone tracking. On the other hand, more cyclones with stronger intensities and longer lifetimes coming from the midlatitudes were detected using the CAA. In addition, the short-lifetime ICs (&lt;18 h) found using the CAA were active (39%) in the CHV, and were typically excluded by the NCP. These ICs had comparable center intensity and showed a good correlation with the occurrence of simultaneous rainfall events.

Forecasting counting and time statistics of compound Cox processes: a focus on intensity phase type process, deletions and simultaneous events

Compound Cox processes (CCP) are flexible marked point processes due to the stochastic nature of their intensity. This paper states closed-form expressions of their counting and time statistics in terms of the intensity and of the mean processes. They are forecast by means of principal components prediction models applied to the mean process in order to reach attainable results. A proposition proves that only weak restrictions are needed to estimate the probability of a new occurrence. Additionally, the phase type process is introduced, which important feature is that its marginal distributions are phase type with random parameters. Since any non-negative variable can be approximated by a phase-type distribution, the new stochastic process is proposed to model the intensity process of any point process. The CCP with this type of intensity provides an especially general model. Several simulations and the corresponding study of the estimation errors illustrate the results and their accuracy. Finally, an application to real data is performed; extreme temperatures in the South of Spain are modeled by a CPP and forecast.

Genetics and Ecological Niche Define Species Boundaries in the Dwarf Milkweed Clade (Asclepias: Asclepiadoideae: Apocynaceae)

Premise of research. Recently diverged taxa may not exhibit strong morphological or DNA sequence differences, making evaluating species boundaries difficult. Finer-scale markers and alternate analytical methods can be used to address species status in these closely related taxa. The dwarf milkweeds have been variably treated as including between one and four species, but no comprehensive assessment of this group has been conducted. Little is known regarding the population genetics of these four putative species, three of which are of conservation concern.Methodology. We used microsatellite markers, population genetic and genetic structure analyses, ecological niche modeling, and approximate Bayesian computation to explore species circumscription and relationships in the group.Pivotal results. Moderate genetic differentiation was detected among four putative species of Asclepias. Genetic clustering revealed four distinct clusters corresponding to the allopatric distributions of the four previously described morphological species. The ecological niche of each of the four dwarf milkweed species is strongly influenced by different sets of bioclimatic variables. Projections of potential suitable habitat in the past indicated that there might have been suitable habitat for all four species by the mid-Holocene, but projections of potential suitable habitat during the Last Glacial Maximum suggest that the current ecological niche of two of the four species was not present at that time. A coalescent scenario of a simultaneous four-way divergence event best fits the data.Conclusions. Multiple lines of evidence reinforce the hypothesis that the dwarf milkweed clade is composed of four morphologically similar but genetically and ecologically distinct species.

Модели времени для сложных распределенных дискретных систем

The impetus for writing this article was the thesis about the inadequacy of using linearly-ordered time models in describing processes in complex discrete systems characterized by the presence of components with independent behavior between the moments of their interaction, with recursively defined, hierarchically organized, varying (dynamic) structure unlimited in complexity, and with non-deterministic behavior. The cause-and-effect relationships between possible events in a distributed multicomponent system leading to changes in its state determine, among other things, the minimally necessary partial order in the set of time instants corresponding to possible events in the system. The time universe is understood to mean the class of isomorphic finite partially-strictly ordered sets as a necessary basic formalism. The above-mentioned concept differs from other well-known formalizations (such as acyclic digraphs, Hasse diagrams, etc.) in that it uses a strictly partial order under the assumption that the set of simultaneous events in the system can be considered as one complex event. The presence of the above-mentioned features of complex systems generates the need to analyze the sets of time universes both in view of possible non-determinism in the behavior of systems and as a consequence of changes resulting from events associated with the system structure itself and the cause-and-effect relationships acting in it. The problem of developing a constructive description—with different degrees of complexity—of time universe sets, primarily infinite ones, which is similar to specifying formal languages as sets of words in a certain alphabet. The authors have solved a similar problem in the theory of directed relationships - the basic formalism for constructing declarative programming languages using the network representation of directed relationships. The key point of such solution is to correctly define the operation of substituting a network into another network instead of some element thereof, which plays the role of entering the network variable into the network structure and has the same specifications as the substituted network. The T-network and T-network language notions introduced in the article, i.e., sets of T-networks, are used to constructively specify the sets of time universes in modeling parallel processes in systems. The main syntactic difference between T-networks and networks of directed relationships is the requirement that T-networks shall not contain cycles, which is ensured by fulfilling certain proposed restrictions posed to network components. The correctness of the substitution operation with respect to these restrictions is proven. The substitution operation can be used both for hierarchically constructing T-networks and for multivariate and recursive assignment of T-network sets. Application of the substitution operation for defining a representative class of context-free T-network languages using context-free T-network grammars is described. A simple grammar example describing the time model for parallel recursive calculation of a definite integral is given, and further research lines are pointed out.