526 research outputs found

    Silent genes and rare males: A fresh look at pheromone blend response specificity in the European corn borer moth, Ostrinia nubilalis

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    The response of male moths from two pheromone races of the European corn borer, Ostrinia nubilalis, was measured in a flight tunnel assay to different ratios of structurally different compounds that comprise the sex pheromone of the Asian corn borer, Ostrinia furnacalis. For both O. nubilalis races, between 1 and 5% of the males completed upwind flights to two different blends of the O. furnacalis pheromone components (the 2:1 Z/E12-14:OAc female-produced blend, and a 97:3 Z/E mix), confirming that rare males exist in the O. nubilalis populations that can detect and respond to mixtures of the O. furnacalis pheromone components. Rare males that responded to the O. furnacalis blends also responded to their own O. nubilalis blends (97:3 or 1:99 Z/E11-14:OAc), indicating that rare O. nubilalis males are not preferentially sensitive to mixtures of the O. furnacalis compounds, but rather that they have a broad range of response specificity, which includes recognition of a wide range of conspecific female-produced ratios, and also recognition of heterospecific mixtures. The results support the hypothesis that saltational shifts in pheromone blend composition (Roelofs et al., 2002) can lead to the evolution of a new species-specific communication system, in part because the broad response specificity of some males includes the ability to respond in an agonistic manner to novel mixtures of compounds. Abbreviation: / E race: using a 1:99 Z/E11-14:Oac blend Z race: using a 97:3 Z/E11-14:OAc blend Z/E-11: the European corn borer, O. nubilalis, blends (Z/E11-14:OAc). Z/E-12: the Asian corn borer, O. furnacalis, blend (Z/E12-14:OAc). bivoltine: one generation per year univoltine: two generations per yea

    Editorial Statement

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    Editorial Statement

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    Editorial Statement

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    Editorial Statement

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    Randomised prospective study for the effect of therapy on residual beta cell function in type-1 diabetes mellitus [ISRCTN70703138]

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    BACKGROUND: Newly diagnosed insulin-dependent diabetes mellitus is characterised by a temporary recovery of endogeneous insulin ("remission") after the beginning of medical treatment with subcutaneous insulin injections. Although most diabetologists think, that insulin reserve is related to reduced occurrence of diabetic long-term complications, such as eye, nerve and kidney disease, there is only one prospective controlled clinical study (the DCCT) addressing this question, however as secondary hypothesis. METHODS/DESIGN: Therefore, we composed a trial consisting of two cohorts with two therapeutic options within each cohort (conventional versus intensive therapy) and a three-year follow-up. In one group the patients are randomly assigned to the treatment regimes to test the statistical alternative hypothesis if variable insulin dosage is superior to fixed insulin injection in preserving insulin reserve measured by C-peptide in serum. Another group includes patients who prefer one of the two therapies, decline randomisation, but consent to follow-up. Apart from the determination of insulin reserve as a biological parameter a second primary endpoint was defined as 'therapeutic failure' according to the criteria of the European Association for the Study of Diabetes. Patients pass a training program to help them self-manage diabetes. A standardised protocol is being set up to minimize centre effects and bias of health care providers. Potential patient dependent bias will be investigated by questionnaires measuring psychic coping processes of people with diabetes. Management of visit dates is directly navigated by the database. Automated visit-reminders are mailed to patients and caregivers to optimise the number of visits on schedule. Data quality is regularly monitored and centres are informed on the results of continuous data management

    Small-amplitude normal modes of a vortex in a trapped Bose-Einstein condensate

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    We consider a cylindrically symmetric trap containing a small Bose-Einstein condensate with a singly quantized vortex on the axis of symmetry. A time-dependent variational Lagrangian analysis yields the small-amplitude dynamics of the vortex and the condensate, directly determining the equations of motion of the coupled normal modes. As found previously from the Bogoliubov equations, there are two rigid dipole modes and one anomalous mode with a negative frequency when seen in the laboratory frame.Comment: 4 pages, no figures, Revte

    Vortex stabilization in a small rotating asymmetric Bose-Einstein condensate

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    We use a variational method to investigate the ground-state phase diagram of a small, asymmetric Bose-Einstein condensate with respect to the dimensionless interparticle interaction strength γ\gamma and the applied external rotation speed Ω\Omega. For a given γ\gamma, the transition lines between no-vortex and vortex states are shifted toward higher Ω\Omega relative to those for the symmetric case. We also find a re-entrant behavior, where the number of vortex cores can decrease for large Ω\Omega. In addition, stabilizing a vortex in a rotating asymmetric trap requires a minimum interaction strength. For a given asymmetry, the evolution of the variational parameters with increasing Ω\Omega shows two different types of transitions (sharp or continuous), depending on the strength of the interaction. We also investigate transitions to states with higher vorticity; the corresponding angular momentum increases continuously as a function of Ω\Omega

    Stability of a vortex in a small trapped Bose-Einstein condensate

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    A second-order expansion of the Gross-Pitaevskii equation in the interaction parameter determines the thermodynamic critical angular velocity Omega_c for the creation of a vortex in a small axisymmetric condensate. Similarly, a second-order expansion of the Bogoliubov equations determines the (negative) frequency omega_a of the anomalous mode. Although Omega_c = -omega_a through first order, the second-order contributions ensure that the absolute value |omega_a| is always smaller than the critical angular velocity Omega_c. With increasing external rotation Omega, the dynamical instability of the condensate with a vortex disappears at Omega*=|omega_a|, whereas the vortex state becomes energetically stable at the larger value Omega_c. Both second-order contributions depend explicitly on the axial anisotropy of the trap. The appearance of a local minimum of the free energy for a vortex at the center determines the metastable angular velocity Omega_m. A variational calculation yields Omega_m=|\omega_a| to first order (hence Omega_m also coincides with the critical angular velocity Omega_c to this order). Qualitatively, the scenario for the onset of stability in the weak-coupling limit is the same as that found in the strong-coupling (Thomas-Fermi) limit.Comment: 8 pages, RevTe

    Int J Environ Res Public Health

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    This scoping study aims to explore the relationships between urban green spaces (UGSs) and the onset, remission and recovery of cancer. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (protocol published in 2018). Eligibility criteria for papers were: (1) to be concerned with UGSs, (2) reporting effects of UGSs on cancer-related outcomes including direct or indirect measures, (3) reporting randomized controlled trials, prospective cohort studies, case studies, observational studies, non-comparative studies, (4) in English or French. The search covered primary studies in the published and unpublished (grey) literatures searching by hand and electronic databases (MEDLINE, Green File, Cumulative Index to Nursing and Allied Health Literature and ScienceDirect). Among 1703 records screened by two reviewers independently, 29 were included for qualitative synthesis. We classify the cancers concerned and the effects reported i.e., protective effect, risk or without association. The most investigated cancers are bladder, breast and lung cancer. Our study also identified contributing factors and their mediating effects between UGSs and cancer. Even though the strength of the evidence of the associations between UGSs and cancer is still weak due to the low number of studies and their design, results highlight the wide variety of possible mediating factors between the use of green spaces and cancer occurrence, remission and/or prevention. Knowledge gaps and future research perspectives should be oriented to qualitative research on protective factors with an attention to equity in UGS access and use
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