2,222 research outputs found
The genetic control of ovariole number in Sitophilus oryzae L (Coleoptera, Curculionidae) is temperature sensitive
The influence of genetical and epigenetical factors on the determinism of the ovariole number was studied in Sitophilus oryzae. This weevil normally possesses 4 ovarioles with apical bacteriomes harbouring symbiotes. By selecting females with a reduced number of ovarioles, the genetic control of this trait was demonstrated with regard to the easy selection of this character and its similar transmission to the progeny by females and males. Several genes could be implicated and a weak maternal effect cannot be rejected. The character is temperature sensitive: at 30°C, abnormal females with 2 or 3 ovarioles prevail, and conversely, normal females appear at 20°C. The reduction of the number of ovarioles is correlated with a decrease in fitness (reduced progeny and lighter body weight of females). Only ovary formation seems to be affected, because a higher progeny per ovariole in abnormal females can be indicative of a normal yolk production in the fat body. Counting bacteria in ovaries shows that the regulation of symbiote number per female occurs at the ovariole itself and not within the whole insect.L’influence de facteurs génétiques et épigénétiques sur le déterminisme du nombre des ovarioles a été étudiée chez Sitophilus oryzae. Ce charançon possède normalement 4 ovarioles terminés par un bactériome apical hébergeant des symbiotes. En sélectionnant les femelles ayant un nombre réduit d’ovarioles, nous avons pu démontrer le contrôle génétique de ce caractère : sélection aisée et transmission à la descendance aussi bien par les femelles que par les mâles. Plusieurs gènes pourraient être impliqués et un léger effet maternel se manifeste par ailleurs. Le caractère est thermo-sensible : à 30°C, les femelles anormales à 2 ou 3 ovarioles sont majoritaires, alors que, à 20°C, le phénotype normal prédomine. La réduction du nombre des ovarioles est corrélée avec une diminution de la fitness (descendance réduite et poids corporel des femelles plus faible). Seule la formation de l’ovaire semble être affectée, car une fertilité plus grande par ovariole chez les femelles anormales indiquerait une production normale de vitellus dans le corps adipeux. Les dénombrements de bactéries dans les ovaires ont montré que la régulation du nombre de symbiotes par femelle intervient au niveau de l’ovariole lui-même, plutôt qu’au niveau de l’insecte entier
The genetic control of ovariole number in Sitophilus oryzae L (Coleoptera, Curculionidae) is temperature sensitive
From policy to practice: exploring practitioners' perspectives on social enterprise policy claims
Thinking about Later Life: Insights from the Capability Approach
A major criticism of mainstream gerontological frameworks is the inability of such frameworks to appreciate and incorporate issues of diversity and difference in engaging with experiences of aging. Given the prevailing socially structured nature of inequalities, such differences matter greatly in shaping experiences, as well as social constructions, of aging. I argue that Amartya Sen’s capability approach (2009) potentially offers gerontological scholars a broad conceptual framework that places at its core consideration of human beings (their values) and centrality of human diversity. As well as identifying these key features of the capability approach, I discuss and demonstrate their relevance to thinking about old age and aging. I maintain that in the context of complex and emerging identities in later life that shape and are shaped by shifting people-place and people-people relationships, Sen’s capability approach offers significant possibilities for gerontological research
Production of volatile fatty acids from slaughterhouse blood by mixed-culture fermentation
The volatile fatty acids (VFA) production potential from animal blood and the factors affecting this process were investigated in this study. In order to simulate an industrial process different operation modes, batch, fed batch and semi-continuous, were also evaluated. Due to high ammonia concentration in fermentation broth, VFA concentration up to 100 g L-1 was achieved without addition of buffer and methanogen inhibitor. In general, acetic, n-butyric and iso-valeric acids were the most predominant species, although different operational conditions affected the VFA concentration, profile, production rate and yield. The microbial community analysis was conducted on the reactors with the best performance, revealing that 70-90% of the microbial population was from the Clostridiales order with a strong presence from the Sporanaerobacter genus. These results demonstrated the feasibility of a VFA-platform bio-refinery using high-protein wastes as substrate via mixed-culture fermentation under non-sterilised conditions
A search for the decay modes B+/- to h+/- tau l
We present a search for the lepton flavor violating decay modes B+/- to h+/-
tau l (h= K,pi; l= e,mu) using the BaBar data sample, which corresponds to 472
million BBbar pairs. The search uses events where one B meson is fully
reconstructed in one of several hadronic final states. Using the momenta of the
reconstructed B, h, and l candidates, we are able to fully determine the tau
four-momentum. The resulting tau candidate mass is our main discriminant
against combinatorial background. We see no evidence for B+/- to h+/- tau l
decays and set a 90% confidence level upper limit on each branching fraction at
the level of a few times 10^-5.Comment: 15 pages, 7 figures, submitted to Phys. Rev.
Evidence for an excess of B -> D(*) Tau Nu decays
Based on the full BaBar data sample, we report improved measurements of the
ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or
mu. These ratios are sensitive to new physics contributions in the form of a
charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) =
0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0
sigma and 2.7 sigma, respectively. Taken together, our results disagree with
these expectations at the 3.4 sigma level. This excess cannot be explained by a
charged Higgs boson in the type II two-Higgs-doublet model. We also report the
observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.Comment: Expanded section on systematics, text corrections, improved the
format of Figure 2 and included the effect of the change of the Tau
polarization due to the charged Higg
Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni
This document is the Accepted Manuscript version of the following article: Thomas Siegert, et al, ‘Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni’, Nature: International Journal of Science, Vol. 531: 341-343, March 2016, DOI: https://doi.org/10.1038/nature16978. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.Microquasars1, 2, 3, 4 are stellar-mass black holes accreting matter from a companion star5 and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 106 to 1010 solar masses. Accretion in microquasars varies on much shorter timescales than in quasars and occasionally produces exceptionally bright X-ray flares6. How the flares are produced is unclear, as is the mechanism for launching the relativistic jets and their composition. An emission line near 511 kiloelectronvolts has long been sought in the emission spectrum of microquasars as evidence for the expected electron–positron plasma. Transient high-energy spectral features have been reported in two objects7, 8, but their positron interpretation9 remains contentious. Here we report observations of γ-ray emission from the microquasar V404 Cygni during a recent period of strong flaring activity10. The emission spectrum around 511 kiloelectronvolts shows clear signatures of variable positron annihilation, which implies a high rate of positron production. This supports the earlier conjecture that microquasars may be the main sources of the electron–positron plasma responsible for the bright diffuse emission of annihilation γ-rays in the bulge region of our Galaxy11. Additionally, microquasars could be the origin of the observed megaelectronvolt continuum excess in the inner Galaxy.Peer reviewe
Search for the decay modes D^0 → e^+e^-, D^0 → μ^+μ^-, and D^0 → e^±μ∓
We present searches for the rare decay modes D^0→e^+e^-, D^0→μ^+μ^-, and D^0→e^±μ^∓ in continuum e^+e^-→cc events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468  fb^(-1). These decays are highly Glashow–Iliopoulos–Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D^0→μ^+μ^- channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman–Cousins method, we set the following 90% confidence level intervals on the branching fractions: B(D^0→e^+e^-)<1.7×10^(-7), B(D^0→μ^+μ^-) within [0.6,8.1]×10^(-7), and B(D^0→e^±μ^∓)<3.3×10^(-7)
Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar
We study the process with
initial-state-radiation events produced at the PEP-II asymmetric-energy
collider. The data were recorded with the BaBar detector at center-of-mass
energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454
. We investigate the mass
distribution in the region from 3.5 to 5.5 . Below 3.7
the signal dominates, and above 4
there is a significant peak due to the Y(4260). A fit to
the data in the range 3.74 -- 5.50 yields a mass value
(stat) (syst) and a width value (stat)(syst) for this state. We do not
confirm the report from the Belle collaboration of a broad structure at 4.01
. In addition, we investigate the system
which results from Y(4260) decay
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