The paper concentrates on modeling the data that can be described by a homogeneous or non-homogeneous Poisson process. The goal is to decide whether the intensity of the process is constant or not. In technical practice, e.g., it means to decide whether the reliability of the system remains the same or if it is improving or deteriorating. We assume two situations. First, when only the counts of events are known and, second, when the times between the events are available. Several statistical tests for a detection of a change in an intensity of the Poisson process are described and illustrated by an example. We cover both the case when the time of the change is assumed to be known or unknown.
We investigated patterns of trait-based community assembly in grasslands sampled along a moisture gradient (216 species) using three continuous species-level traits (maximum species height, minimum species height, seed mass), as well as seven nominal traits (flowering phenology, fruit type, pollen vector, clonal growth organs – CGOs, branching type, leaf distribution, lateral spread), some of which are unusual in that a species may possess more than one state per trait simultaneously (e.g. CGO). Additionally, this study tests whether patterns of assembly vary with plot biomass and moisture using both presence-absence and abundance-weighted analyses (two plot sizes: 25 × 25 cm, 75 × 75 cm). Plant species in these grasslands were randomly organized with respect to both maximum and minimum species height; however, coexisting plant species had a significantly smaller mean seed mass than expected by chance, and were significantly convergent in seed mass, consistent with observations from one previous study, and with theory related to environmental or competitive filtering. These patterns were consistent across plot sizes, and were similar whether analyses were abundance-weighted or not, although partitioned analyses show that these patterns are most pronounced in wet grasslands. Grasslands were non-randomly assembled with respect to five of our ten traits including seed mass, fruit type, CGO, branching type and leaf distribution. Among these, only patterns of branching type clearly conformed to the predictions from Limiting Similarity Theory, suggesting that variation in this trait may contribute to species coexistence in these grasslands. In two cases (fruit type, branching type), results differed in significance depending on whether analysis used presence-absence or abundance data; incorporating abundance may be more relevant, however, cover-based abundance measures in small plots can bias trait representation in favour of size over ramet number. In general, patterns were consistent across the two plot sizes. For four traits (seed mass, flowering phenology, leaf distribution and lateral spread) plot-level effect sizes of our tests varied significantly with plot-level biomass production; the slope of these relationships was positive for seed mass, but negative for flowering phenology, leaf distribution and lateral spread. For seven of ten traits, plot-level effect sizes varied significantly with plot-level soil moisture, with positive regression slopes for some traits (flowering phenology, leaf distribution), and negative slopes for others (minimum height, seed mass, fruit type, pollen vector, CGO). These results indicate that community assembly rules related to different functional traits can be responsive to variation in either biomass or soil moisture, or both.
The intra- and interspecific variability in the West Palaearctic tibialis-group species of the subgenus Pandasyopthalmus (Diptera: Syrphidae: Paragus) was analysed. Novel immature and molecular characters were studied and the traditionally used adult characters reviewed with the aim of establishing the status of the most widespread taxa of the tibialis-group in the Palaearctic region. Moreover, a review of the morphology of the larvae of the subgenus Pandasyopthalmus is also presented and includes the first description of the chaetotaxy of the larval head of Syrphidae. The larval morphology showed a continuum between two extremes. There is intraspecific variability in the male genitalia characters typically used for diagnostic species identification in this group. Molecular characters of the mitochondrial cytochrome c-oxidase subunit I (COI) was invariant for the West Palaearctic Pandasyopthalmus taxa analysed. Despite the fact that no great differences were found when compared with Afrotropical tibialis-group individuals (uncorrected pairwise divergence 0.17-0.35%), the divergences of the West Palaearctic vs. Nearctic and Austral-Oriental tibialis-group taxa varied between 1.15-2.75% (uncorrected pairwise divergence). Molecular characters of the nuclear ribosomal internal transcribed spacer region (ITS2) revealed several molecular haplotypes of a dinucleotide repeat that was not constrained to morphospecies or to populations of the same geographic origin. The closely related and morphologically similar species of the tibialis-group known from the West Palaearctic region are separable in most cases only by the shape and size of male postgonites. The results of this study support the presence of a single polymorphic taxon in the West Palaearctic region (or a very recent origin of the taxa studied). Moreover larval morphology and the lack of a clear relation between ITS2 haplotypes and the geographic distribution or adult morphology, support the taxonomic implications of barcode taxonomy based on mitochondrial DNA for this species-group of Syrphidae.
Inspired by Rakonczai et al. [8], we use autocopulas for the testing of linearity against Markov-switching type of nonlinearity and remaining nonlinearity. They applied this autocopula approach to testing heteroscedasticity in AR-ARCH model. Given a strictly stationary time series Yt, a k-lag autocopula is a bivariate joint distribution function of the random vector (Yt, Yt-k). Our contribution is in extending the idea to test the linearity against Markov-switching type of nonlinearity and remaining nonlinearity [5,6] in order to avoid classical, time-consuming tests.
The aim of this paper is the analysis of temporal changes in multipath propagation errors on the pseudorange GNSS signal used for positioning, and its behavior during the calendar year (the quality of signal depends on e.g. foliage of trees, changes reflectivity surfaces due to rain or snow, etc.). The analysis was performed on data measured on a stationary point at Geodetic Observatory Pecný at Ondřejov, where one day was chosen as a constant time unit. Given the relatively highly unfavorable configuration of the experiment, RMS value of multipath is up to 60 cm on C1 and 40 cm on C2. These values vary with different weather conditions between 10 and 20 cm.
Leafrollers can experience high levels of indigenous parasitism in organically managed apple orchards and the augmentative release of specific parasitoid species to suppress these secondary pests may be advantageous in orchards converting to non-chemical pest management. Caged and uncaged releases of two ichneumonid [Apophua simplicipes (Cresson) and Glypta variegata Dasch] and two braconid (Macrocentrus linearis Nees and Apanteles polychrosidis Viereck) koinobiont endoparasitoids of the obliquebanded leafroller, Choristoneura rosaceana (Lepidoptera: Tortricidae) on host-infested potted apple trees were conducted to assess the parasitoids' abilities to find and successfully parasitize sentinel hosts under orchard conditions. Seasonal timing of the trials varied for each parasitoid species, based on their relative performance under simulated summer/fall conditions in laboratory trials. After the release of five or fifty parasitoid females, the mean percent parasitism of leafroller larvae collected from infested trees ranged from 0 to 75% depending on the parasitoid species involved. Although caged releases tended to increase the percentage of live parasitized hosts in release treatments, uncaged releases provided a more realistic assessment of the parasitoid's ability to seek and find hosts within an infested area over a longer period. Release of the large, solitary A. simplicipes, had the most significant impact on the host population density.
Sex and gender matter in all aspects of life. Humans exhibit sexual dimorphism in anatomy, physiology, but also pathology. Many of the differences are due to sex chromosomes and, thus, genetics, other due to endocrine factors such as sex hormones, some are of social origin. Over the past decades, huge number of scientific studies have revealed striking sex differences of the human brain with remarkable behavioral and cognitive consequences. Prenatal and postnatal testosterone influence brain structures and functions, respectively. Cognitive sex differences include especially certain spatial and language tasks, but they also affect many other aspects of the neurotypical brain. Sex differences of the brain are also relevant for the pathogenesis of neuropsychiatric disorders such as autism spectrum disorders, which are much more prevalent in the male population. Structural dimorphism in the human brain was welldescribed, but recent controversies now question its importance. On the other hand, solid evidence exists regarding gender differences in several brain functions. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences in healthy individuals and people in the autism spectrum.
Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by impairment in social communication and presence of stereotyped/restricted behaviors. Children with ASD very often demonstrate co-morbid psychiatric problems, problems known to be affected by testosterone in neurotypical populations. However, there are few reports investigating relationships between testosterone and psychiatric conditions in children with ASD. The aim of this study was to determine the relationship between plasmatic levels of testosterone and behavioral/emotional problems in pre-pubertal boys with ASD. The study sample consisted of 31 pre-pubertal boys (ages 3-10) with ASD. Parents completed the Nisonger Child Behavior Rating Form (NCBRF) to assess specific behavioral/emotional problems as observed in the previous 2 months. Plasmatic testosterone levels were determined in boys according to standardized procedures. It was found that there were positive correlations between testosterone levels and the conduct problems subscale (p=0.034, rs=0.382) of NCBRF and also between testosterone levels and the hyperactive subscale (p=0.025, rs=0.402) of NCBRF. Findings in this study are in line with research conducted in the neurotypical population. This is the first large study investigating testosterone and emotional/behavioral problems in ASD and warrants further research in this field in order to clarify the etiopathogenesis of psychiatric co-morbidities and improve their treatment., A. Pivovarciova, J. Durdiakova, S. Hnilicova, D. Filcikova, D. Ostatnikova., and Obsahuje bibliografii
Karcinom žaludku je ve světě druhou nejčastější příčinou úmrtí na malignitu. V rámci jednotlivých stadií může být prognóza nádoru velmi rozdílná, proto se zájem onkologů upíná k hledání nových prognostických a prediktivních markerů, jako je např. HER-2/neu (HER2). Po jeho stimulaci dochází k nastartování signální dráhy, vedoucí ke zvýšené proliferaci, zablokování apoptózy, ztrátě diferenciace a zvýšení invazivity nádoru. HER2 je negativním prognostickým faktorem, sdruženým s vyšší invazivitou, postižením serózy, metastazováním do uzlin a kratším přežitím, i negativním prediktivním faktorem a cílem pro biologickou léčbu trastuzumabem. Existují dvě metody detekce HER2 – imunohistochemie (IHC) a in situ hybridizace (ISH). Pozitivita HER2 se u karcinomu žaludku pohybuje v rozmezí 6,8–34 % (průměrně 17,6 %) při stanovení IHC, resp. 7,1–42,6 % (průměrně 19,2 %) pomocí ISH. HER2 je častěji přítomen v intestinálním, než v difuzním typu karcinomu. Při stanovení HER2 platí některá specifika – za pozitivní považovány jak buňky s kompletní, tak s pouze bazolaterální expresí proteinu, vzhledem k častěji nehomogenní expresi je dolní hranice v resekátech 10 % pozitivních buněk, ale u endobioptických vzorků je vyžadována přítomnost alespoň jedné skupiny barvících se (2+ nebo 3+) neoplastických buněk., Gastric carcinoma is the second cause of cancer related death worldwide. Prognosis significantly varies among patients within the same stage, therefore oncologists urge for identification of new prognostic and predictive markers, such as HER-2/neu (HER2). Stimulation of HER2 triggers molecular pathway resulting in increased proliferation, blocked apoptosis, loss of differentiation and increased tumor invasion. HER2 is a negative prognostic factor, associated with increased invasiveness, serosal involvement, lymph-node metastases and shorter survival, as well as a negative predictive marker and target for trastuzumab treatment. There are two methods of HER2 detection – immunohistochemistry (IHC) and in situ hybridisation (ISH). Positivity of HER2 in gastric cancer ranges from 6,8 to 34 % (mean 17,6 %) in IHC detection, and 7,1–42,6 % (mean 19,2 %) in ISH detection, respectively. HER2 is more often positive in intestinal than in diffuse type. HER2 detection in gastric carcinoma shows certain specific features – positive cells show either complete or incomplete basolateral (Ushaped) membranous expression. Due to more frequent inhomogenity of tumor population, the threshold has been set at 10 % of positive cells in resection specimens, but even one cohesive cluster of positive (2+ or 3+) neoplastic cells is sufficient in biopsy samples., Aleš Ryška, Tomáš Rozkoš, Jan Laco, and Lit.: 24