Search

Egg parasitoids of the family Scelionidae are important biological control agents in many agricultural systems, including rice. Several species attack Pentatomidae. Some are used in applied biological control programs. We studied the richness, abundance, and population fluctuations of scelionids through gradients of distance from the forest near the cultivated areas and in two stages of plant development under different rice managements. The work took place in two irrigated rice crops, one with organic management (O.M.) and another with conventional management (C.M.), in the municipality of Nova Santa Rita, Rio Grande do Sul, Brazil, during the 2013/2014 and 2014/2015 seasons. The parasitoids were collected with Malaise traps placed at different distances in relation to the riparian forest surrounding the rice crop. Specimens were collected twice a month from seeding until the rice harvest. The most abundant genera were Idris, Telenomus, and Baeus. Telenomus podisi, Telenomus sp. 3, Telenomus sp. 2, and Telenomus sp. 1, were the most abundant morphospecies, and their abundance changed over the plant stages and seasons. The rice phenological stage influenced the diversity over the two seasons and, in the second one, the kind of pesticide used possibly had a negative influence on the parasitoid assemblage in conventional management. Close to the forest, there was a greater abundance of Scelionidae in the C.M. area in the first season. This was not found in the O.M. area at any crop season. The high abundance of scelionids indicates that natural biological control may be important in the rice crop, particularly in areas under organic management. [ABSTRACT FROM AUTHOR]

There is a well known algebraic process by which spreads and quasifibrations with their representative partial spreads are within PG(3, K), where K is a field that admits a quadratic field extension may be "lifted" to a corresponding spread or quasifibration, respectively. The lifted quasifibrations are derivable maximal partial spreads within P G (3 , K (τ)) , where K (τ) , denotes the associated quadratic field extension of K. In this article, we ask whether there is any sort of "lifting" process for spreads written over non-commutative skewfields. We consider where the lifting theory might extend to quasifibrations that live in PG(3, K), where K is considered to be a non-commutative skewfield. We are able to show that any non-commutative skewfield that admits a central Galois quadratic extension skewfield always may be lifted to a new semifield. This occurs, in particular, in most quaternion skewfield planes and since there is a matrix representation of a quaternion skewfield within GL(3, K), for certain fields K, there are then two mutually non-isomorphic skewfield planes constructed in mutually non-isomorphic 3-dimensional projective spaces. Taken purely algebraically, this lifting construction is similar to what might be called a Cayley–Dickson procedure, as the constructed semifields, although not algebras, are the resultant when applying this procedure to a central Galois quadratic extension quaternion division ring, thereby losing associativity. [ABSTRACT FROM AUTHOR]

The egg parasitoid Telenomus remus (Hymenoptera: Scelionidae) has been investigated for classical and applied biological control of noctuid pests, especially Spodoptera (Lepidoptera: Noctuidae) species. Although T. remus was introduced into Brazil over three decades ago for classical biological control of S. frugiperda, this wasp has not been recorded as established in corn or soybean crops. We used an integrative approach to identify T. remus, combining a taxonomic key based on the male genitalia with DNA barcoding, using a cytochrome c oxidase subunit I mitochondrial gene fragment. This is the first report of natural parasitism of T. remus on S. frugiperda and S. cosmioides eggs at two locations in Brazil. We also confirmed that the T. remus lineage in Brazil derives from a strain in Venezuela (originally from Papua New Guinea and introduced into the Americas, Africa, and Asia). The occurrence of T. remus parasitizing S. frugiperda and S. cosmioides eggs in field conditions, not associated with inundative releases, suggests that the species has managed to establish itself in the field in Brazil. This opens possibilities for future biological control programs, since T. remus shows good potential for mass rearing and egg parasitism of important agricultural pests such as Spodoptera species. [ABSTRACT FROM AUTHOR]

Trissolcus plautiae (Watanabe) is known as a major egg parasitoid of the brown-winged green bug Plautia stali Scott, which is a serious pest of various fruit trees in Japan. Although T. plautiae was synonymized with T. japonicus (Ashmead) in 1981, both scientific names have been used for the same egg parasitoid of P. stali for about the past 30 years because of their taxonomic confusion. To promote an effective IPM program for P. stali using its egg parasitoids, we attempted to resolve the confusion by the use of a variety of methods. On detailed observation of adult morphology, we found that sublateral setae on the T1 are present in T. plautiae and absent in T. japonicus, and that this morphological difference is corroborated by more subtle differences between the two species. This finding supports the view that they are different species. The view was also supported by the results of mating experiments to determine the reproductive isolation of T. plautiae from T. japonicus and DNA analysis of these two species. We conclude that T. plautiae is a cryptic species of T. japonicus and resurrect T. plautiae from T. japonicus stat. rev. [ABSTRACT FROM AUTHOR]

The article provides information regarding integers. It states that integer's notion develops as soon as the number set is expanded for the inclusion of ratio set. It also mentions the definition of complex and real integers by Richard Dedekind. It adds that Sir William Rowan Hamilton discovered quaternions integers in 1843.

A focal-spread of order q and type ( t, k), t > k is a partition of a vector space of dimension t + k over GF( q) by a one subspace of dimension t, the 'focus' and a partial Sperner k-spread of degree q. In this article, a complete classification is given of focal-spreads that admit a doubly transitive group on the partial Sperner k-space. [ABSTRACT FROM AUTHOR]

Purpose: A general consensus exists that severe mental illness (SMI) increases violence risk. However, a recent report claimed that SMI 'alone was not statistically related to future violence in bivariate or multivariate analyses.' We reanalyze the data used to make this claim with a focus on causal relationships between SMI and violence, rather than the statistical prediction of violence. Methods: Data are from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a two-wave study ( N = 34,653: Wave 1: 2001-2003; Wave 2: 2004-2005). Indicators of mental disorder in the year prior to Wave 1 were used to examine violence between Waves 1 and 2. Results: Those with SMI, irrespective of substance abuse status, were significantly more likely to be violent than those with no mental or substance use disorders. This finding held in both bivariate and multivariable models. Those with comorbid mental and substance use disorders had the highest risk of violence. Historical and current conditions were also associated with violence, including childhood abuse and neglect, household antisocial behavior, binge drinking and stressful life events. Conclusions: These results, in contrast to a recently published report, show that the NESARC data are consistent with the consensus view on mental disorder and violence: there is a statistically significant, yet modest relationship between SMI (within 12 months) and violence, and a stronger relationship between SMI with substance use disorder and violence. These results also highlight the importance of premorbid conditions, and other contemporaneous clinical factors, in violent behavior. [ABSTRACT FROM AUTHOR]

Contrary to popular belief, evolution is not necessarily progressive. Indeed, traits are often lost or substantially reduced in the process of evolution. In this article, we present several case studies that can be used in the classroom to illustrate both the ubiquity and diversity of cases of trait loss. Our recently acquired knowledge of genetic and developmental processes can provide insight into how traits are gained and lost through evolution. Several practical applications also emerge from studies of trait loss and degeneration, and we focus on those with medical relevance. Examining trait loss also provides perspective on the crucial differences between Darwinian evolution and social Darwinism. We encourage educators to devote greater attention to trait loss in secondary biology and undergraduate evolution courses, and discuss how such information may be best incorporated into evolution curricula. [ABSTRACT FROM AUTHOR]

The following syndrome of features occurs in several groups of phytophagous insects: (1) wingless females, (2) dispersal by larvae, (3) woody hosts, (4) extreme polyphagy, (5) high abundance, resulting in status as economic pests, (6) invasiveness, and (7) obligate parthenogenesis in some populations. If extreme polyphagy is defined as feeding on 20 or more families of hostplants, this syndrome is found convergently in several species of bagworm moths, tussock moths, root weevils, and 5 families of scale insects. We hypothesize that extreme polyphagy in these taxa results from 'niche explosion', a positive feedback loop connecting large population size to broad host range. The niche explosion has a demographic component (sometimes called the 'amplification effect' in studies of pathogens) as well as a population-genetic component, due mainly to the increased effectiveness of natural selection in larger populations. The frequent origins of parthenogenesis in extreme polyphages are, in our interpretation, a consequence of this increased effectiveness of natural selection and consequent reduced importance of sexuality. The niche explosion hypothesis makes detailed predictions about the comparative genomics and population genetics of extreme polyphages and related specialists. It has a number of potentially important implications, including an explanation for the lack of observed trade-offs between generalists and specialists, a re-interpretation of the ecological correlates of parthenogenesis, and a general expectation that Malthusian population explosions may be amplified by Darwinian effects. [ABSTRACT FROM AUTHOR]

Conserving biological diversity in a changing climate poses major challenges for land managers and society. Effective adaptive strategies for dealing with climate change require a socio-ecological systems perspective. We highlight some of the projected ecological responses to climate change in the Pacific Northwest, U.S.A and identify possible adaptive actions that federal forest managers could take. The forest landscape, ownership patterns and recent shift toward ecologically based forest management provide a good starting place for conserving biological diversity under climate change. Nevertheless, undesirable changes in species and ecosystems will occur and a number of adaptive actions could be undertaken to lessen the effects of climate change on forest ecosystems. These include: manipulation of stand and landscape structure to increase ecological resistance and resilience; movement of species and genotypes; and engaging in regional, multi-ownership planning to make adaptive actions more effective. Although the language and goals of environmental laws and policies were developed under the assumption of stable climate and disturbance regimes, they appear to be flexible enough to accommodate many adaptive actions. It is less certain, however, if sufficient social license and economic capacity exist to undertake these actions. Given the history of contentious and litigious debate about federal forest management in this region, it is likely that some of these actions will be seen as double-edge swords, spurring social resistance, especially where actions involve cutting trees. Given uncertainties and complexity, collaborative efforts that promote learning (e.g. adaptive management groups) must be rejuvenated and expanded. [ABSTRACT FROM AUTHOR]

The bilinear flocks of Cherowitzo are generalized to a large variety of bilinear flocks of the cone $${\mathcal{C}_q}$$ . Using these ideas, net replacements of certain Hughes-Kleinfeld planes of order q are obtained that construct every André plane in PG(3, q). [ABSTRACT FROM AUTHOR]

The Suetake planes and the simple full non-square André planes are shown to be exactly those finite translation planes that are coupled with a semifield plane. Also, the Suetake planes are never generalized André planes. [ABSTRACT FROM AUTHOR]

New classes of mutually disjoint hyper-reguli of order q n, for n > 2, are determined, which are not André hyper-reguli if n > 3. If n is odd, each hyper-regulus permits at least two replacements and if q is odd and ( n, q−1) = 1, there are ( q−1)/2 mutually disjoint hyper-reguli each of which may be replaced at least two ways. Each of the possible 2( q-1)/2 translation planes constructed is not André or generalized André. There are also new constructions of mixed subgeometry partitions. [ABSTRACT FROM AUTHOR]

Background: Population-based cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute (NCI) are mainly based on medical records and administrative information. Individual-level socioeconomic data are not routinely reported by cancer registries in the United States because they are not available in patient hospital records. The U.S. representative National Longitudinal Mortality Study (NLMS) data provide self-reported, detailed demographic and socioeconomic data from the Social and Economic Supplement to the Census Bureau's Current Population Survey (CPS). In 1999, the NCI initiated the SEER-NLMS study, linking the population-based SEER cancer registry data to NLMS data. The SEER-NLMS data provide a new unique research resource that is valuable for health disparity research on cancer burden. We describe the design, methods, and limitations of this data set. We also present findings on cancer-related health disparities according to individual-level socioeconomic status (SES) and demographic characteristics for all cancers combined and for cancers of the lung, breast, prostate, cervix, and melanoma.Methods: Records of cancer patients diagnosed in 1973-2001 when residing 1 of 11 SEER registries were linked with 26 NLMS cohorts. The total number of SEER matched cancer patients that were also members of an NLMS cohort was 26,844. Of these 26,844 matched patients, 11,464 were included in the incidence analyses and 15,357 in the late-stage diagnosis analyses. Matched patients (used in the incidence analyses) and unmatched patients were compared by age group, sex, race, ethnicity, residence area, year of diagnosis, and cancer anatomic site. Cohort-based age-adjusted cancer incidence rates were computed. The impact of socioeconomic status on cancer incidence and stage of diagnosis was evaluated.Results: Men and women with less than a high school education had elevated lung cancer rate ratios of 3.01 and 2.02, respectively, relative to their college educated counterparts. Those with family annual incomes less than $12,500 had incidence rates that were more than 1.7 times the lung cancer incidence rate of those with incomes $50,000 or higher. Lower income was also associated with a statistically significantly increased risk of distant-stage breast cancer among women and distant-stage prostate cancer among men.Conclusions: Socioeconomic patterns in incidence varied for specific cancers, while such patterns for stage were generally consistent across cancers, with late-stage diagnoses being associated with lower SES. These findings illustrate the potential for analyzing disparities in cancer outcomes according to a variety of individual-level socioeconomic, demographic, and health care characteristics, as well as by area measures available in the linked database. [ABSTRACT FROM AUTHOR]

A classification is given of all projective translation planes of order q 2 that admit a collineation group G admitting a two-transitive orbit of q + 1 points. [ABSTRACT FROM AUTHOR]

A new class of translation planes of order q n that admit very small affine homology groups is constructed. These planes are constructed by the replacement of a new hyper-regulus that cannot be an André hyper-regulus. Hence, the planes cannot be André or generalized André. [ABSTRACT FROM AUTHOR]

Let S k denote a set of k reguli in a Desarguesian affine plane $$\sum_{q^2}$$ of order q 2. It is shown that, for every odd integer s > 1, there is a corresponding set S s k of k reguli in any Desarguesian plane $$\sum_{q^{2s}}$$ of order q 2 s such the line intersection properties of the reguli of S s k are inherited from those of S k . Hence, sets of mutually disjoint reguli in $$\sum_{q^2}$$ ‘lift’ to sets of mutually disjoint reguli in $$\sum_{q^{2s}}$$ . Thus, the existence of a subregular spread in PG(3, q) produces an infinite class of subregular spreads in spaces PG(3, q s ). [ABSTRACT FROM AUTHOR]

Johnson showed that the only doubly transitive parallelisms of PG(3, q) are exactly the two regular parallelisms in PG(3, 2). This article completely generalizes this result to doubly transitive t-parallelisms of arbitrary finite projective spaces. [ABSTRACT FROM AUTHOR]

New classes of subregular planes are constructed that admit elation groups or Baer groups of order > 2. Further, we construct a variety of large dimension translation planes admitting many elations. [ABSTRACT FROM AUTHOR]

Every semifield plane with spread in PG(3, K), where K is a field admitting a quadratic extension K +, is shown to admit a transitive parabolic unital. [ABSTRACT FROM AUTHOR]

The translation planes of order 81 admitting SL(2, 5), generated by affine elations, are completely determined. There are seven mutually non-isomorphic translation planes, of which five are new. Each of these planes may be derived producing another set of seven mutually non-isomorphic translation planes admitting SL(2, 5), where the 3-elements are Baer. Of this latter set, five planes are new. [ABSTRACT FROM AUTHOR]

Using ‘fusion’ methods on finite semifields, a variety of partitions (flocks) of Segre varieties by caps are obtained. The partitions arise from semifield planes and are thus called “semifield flat flocks”. Furthermore, the finite transitive semifield flat flocks are completely determined. [ABSTRACT FROM AUTHOR]

A classification is given of all spreads in PG(3, q), q = p r, p odd, whose associated translation planes admit linear collineation groups of order q( q +1) such that a Sylow p-subgroup fixes a line and acts non-trivially on it. [ABSTRACT FROM AUTHOR]

A complete classification of the semifield spreads of order q4 that triply-retract to mixed partitions of PG(3, q²) is given. [ABSTRACT FROM AUTHOR]

A complete classification of the semifield spreads of order q4 that triply-retract to mixed partitions of PG(3, q²) is given. [ABSTRACT FROM AUTHOR]

A question raised by Ostrom on the existence of hyper-reguli that are not André hyper-reguli is completely determined for hyper-reguli of order $q^{t}$ where t is composite. Various new types of ‘generalized André replacements’ are constructed that produce many new classes of generalized André planes. In general, for t=ds, new non-André quasi-subgeometry partitions are constructed of ${\it PG}(s-1,q^{d})$ by quasi-subgeometries isomorphic to PG$(ds/e-1,q^{e})$, for various divisors e of d. When $d=2$, this produces new non-André sub-geometry partitions of PG $(2s-1,q^{2})$ by subgeometries isomorphic to PG $(2s-1,q)$ and PG$(s-1,q^{2})$. [ABSTRACT FROM AUTHOR]

New and old results on parallelisms of projective spaces are surveyed. [ABSTRACT FROM AUTHOR]

Translation planes of order q2 containing non-Desarguesian Baer subplanes are used to construct transversal-free translation nets with very small deficiencies. Also, a generalization of the ideas of Bruen shows that any non-Desarguesian spread in PG(3, q) produces a transversal-free net of small deficiency. [ABSTRACT FROM AUTHOR]

From illustrative examples of research on the best-studied group of species to date, Drosophila melanogaster and its closest relatives, we argue that selection is multifarious, but often hidden. Selective fixation of new, highly advantageous alleles is the most parsimonious explanation for a typical pattern of molecular variation observed in genomic regions characterized by very low recombination: drastically reduced DNA sequence variation within species and typical levels of sequence divergence among species. At the same time, the identity of the gene (or genes) influenced by selection is not just difficult to discern; it may be impossible. Studies of the genetic basis of reproductive isolation demonstrate that, although the D. melanogaster complex species appear virtually identical, dozens of currently unidentified genes contribute to hybrid sterility. We argue that these findings are best explained by selectively-driven functional divergence and demonstrate the multifarious nature of selection. Although multifarious selection certainly occurs, the exact characters responsible for differences in survival and reproductive success are unknown. We do not see these inherent limits as a cause for despair or a problem for evolutionary biology. Instead, we hope to raise awareness of these complexities of evolution by highlighting both the progress and the limitations of characterizing multifarious natural selection. [ABSTRACT FROM AUTHOR]

Translation planes with spreads in PG(3, q) that admit 'many homologies' (more than q + 1 axes) of odd order u are completely classified. [ABSTRACT FROM AUTHOR]

Despite the recent synthesis of developmental genetics and evolutionary biology, current theories of adaptation are still strictly phenomenological and do not yet consider the implications of how phenotypes are constructed from genotypes. Given the ubiquity of regulatory genetic pathways in developmental processes, we contend that study of the population genetics of these pathways should become a major research program. We discuss the role divergence in regulatory developmental genetic pathways may play in speciation, focusing on our theoretical and computational investigations. We also discuss the population genetics of molecular co-option, arguing that mutations of large effect are not needed for co-option. We offer a prospectus for future research, arguing for a new synthesis of the population genetics of development. [ABSTRACT FROM AUTHOR]

We investigate finite affine planes π of even order possessing a parabolic oval Ω (|Ω ∩ l[sub ∞]| = 1) and a collineation group G which leaves Ω invariant and acts 2-transitively on its affine points. The main attention is devoted to translation planes. The odd order case has already been considered by Enea and Korchmaros in [5]. Our main result shows that if π has even ordern ≠ 2[sup 6] and possesses two 2-transitive parabolic ovals which share at least two, but not all their affine points, then π is Desarguesian. [ABSTRACT FROM AUTHOR]

Constructions are given of various classesof maximal partial spreads in PG(3,2 r) whose partialspreads consist of q/2 reguli sharing a line. Further,characterization results are given for the main classes of constructedmaximal partial spreads. [ABSTRACT FROM AUTHOR]

In this article, the parallelisms whichadmit doubly transitive groups are completely classified as thetwo regular parallelisms in $$PG\left( {3,2} \right)$$ . [ABSTRACT FROM AUTHOR]

Discusses connections between Desarguesian partial parallelisms of deficiency. Translation planes admitting an isomorphic collineation group which is generated by Baer collineations; Infinite class of regular parallelisms; Construction of regular parallelisms using a cyclic group.

Discusses translation planes admitting a nonsolvable doubly transitive line-sized orbit. Classification of all finite translation plans of order that admit a collineation group; Inducement of a nonsolvable doubly transitive collineation group on a set of affine points; Collineation group that could act doubly transitive on a parabolic oval.

Determines the structure of the collineation groups in vector space nets over skewfields. Structure theory of a point-Baer collineation; Definition of a direct product of affine planes; Uses of the term kernel of a translation plane.

Examines the bilinear forms of quadratic cones. Presentation of the elliptic coordinates of bilinear flocks; Construction of bilinear planes by net replacement; Discussion of replacement theory.

We compare mortality differences for specific and general categories of occupations using a national cohort of approximately 380,000 persons aged 25-64 from the U.S. National Longitudinal Mortality Study. Based on comparisons of relative risk obtained from Cox proportional-hazards model analyses, higher risk is observed in moving across the occupational spectrum from the technical, highly skilled occupations to less-skilled and generally more labor-intensive occupations. Mortality differences obtained for social status groups of specific occupations are almost completely accounted for by adjustments for income and education. Important differences are shown to exist for selected specific occupations beyond those accounted for by social status, income, and education. High-risk specific occupations include taxi drivers, cooks, longshoremen, and transportation operatives. Low-risk specific occupations include lawyers, natural scientists, teachers, farmers, and a variety of engineers. [ABSTRACT FROM AUTHOR]

The Desarguesian, Hall, and Hering translation planes of order q2 are characterized as exactly those translation planes of odd order with spreads in PG (3,q) that admit a linear collineation group with infinite orbits one of length q+1 and i of length (q-q) /i for i=1 or 2. [ABSTRACT FROM AUTHOR]

We investigate autotopisms and isotopisms of generalized twisted field planes. A revision of Albert′s results is developed using a mixture of group-theoretical and algebraic methods. In particular, transitivity conditions of the autotopism group on the nonvertex points of one or more sides of the autotopism triangle are determined. Also, correlations and polarities in generalized twisted field planes are examined in detail. These results allow us to obtain several improvements of recent results in semifield planes. [ABSTRACT FROM AUTHOR]