27 research outputs found
Generational Mass Splitting of Neutrinos in High Temperature Gauge Theory
We calculate the generational mass splitting of neutrinos in high temperature
gauge theory when the temperature
is above GeV and the gauge symmetry is restored. We consider the case of
neutrinos that are massless at tree level as well as the case of neutrinos with
tree-level mass and large mixing.Comment: 12 Pages, JHU-TIPAC-940008/INFNCA-TH-94-
Sexual development of wild and mass-reared male Queensland fruit flies in response to natural food sources
Diet has a profound influence on the fitness of adult tephritid flies. Mass-reared flies are provided yeast hydrolysate as a rich source of nutrition that supports rapid sexual development and mating success. In contrast, wild tephritid flies often live in environments where food may be hard to find,
and these are the conditions that sexually immature mass-reared sterile males encounter when released into the field during sterile insect technique campaigns. The effect of natural food sources (bat guano, bird droppings, citrus pollen, and wheat pollen) on the sexual development of adult mass-reared fertile, mass-reared sterile, and wild male Queensland fruit flies, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), was determined bymeasuring ejaculatory apodeme size. Inclusion of yeast hydrolysate in the adult diet was associated with faster growth of the ejaculatory apodeme in comparison with all other diets. Effects of diet were far less pronounced in mass-reared males, which may indicate reduced nutritional requirements, whereas the ejaculatory apodeme of wild males fed
on natural sources of food or sucrose alone did not increase in size over the first 20 days of adult life
Geographic variation and plasticity in climate stress resistance among southern African populations of Ceratitis capitate (Weidemann) (Diptera: Tephritidae)
Traits of thermal sensitivity or performance are typically the focus of species distribution modelling. Among-population trait variation, trait plasticity, population connectedness and the possible climatic covariation thereof are seldom accounted for. Here, we examine multiple climate stress resistance traits, and the plasticity thereof, for a globally invasive agricultural pest insect, the Mediterranean
fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). We also accounted for body size and population genetic connectivity among distinct populations from diverse bioclimatic regions across southern Africa. Desiccation resistance, starvation resistance, and critical thermal minimum (CTmin) and maximum (CTmax) of C. capitata varied between populations. For thermal tolerance traits, patterns of flexibility in response to thermal acclimation were suggestive of beneficial acclimation, but this was not the case for desiccation or starvation resistance. Population differences in measured traits were larger than those associated with acclimation, even though gene flow was high. Desiccation resistance was weakly but positively affected by growing degree-days. There was also a weak positive relationship between CTmin and temperature seasonality, but CTmax was weakly but negatively affected by the same
bioclimatic variable. Our results suggest that the invasive potential of C. capitata may be supported by adaptation of tolerance traits to local bioclimatic conditions
Magnetic properties of neutrinos in high temperature SU(2)XU(1) gauge theory
We calculate the finite temperature self-energy for neutrinos in the presence
of a constant magnetic field in a medium in the unbroken
model. We obtain the exact dispersion relation for such neutrinos and find that
the thermal effective mass is modified by the magnetic field. We also find a
simple analytic expression for the dispersion relation and obtain the index of
refraction for large neutrino momentum.Comment: 13 pp, RevTeX, no figure
Sex differences in developmental response to yeast hydrolysate supplements in adult Queensland fruit fly
Post-teneral dietary supplements have been found to improve mating performance of male Bactrocera
tryoni (Froggatt) (Diptera: Tephritidae) (Q-fly) and show considerable promise for enhancement
of sterile insect technique (SIT) programmes even when applied within the current 48 h
pre-release holding period. However, Q-flies are released as a bisexual strain, and the positive effects
of a diet including yeast hydrolysate for males may also boost reproductive development and sexual
performance of females. Increased prevalence of mature sterile females can substantially dilute SIT
efficacy as mating capacity of sterile males is largely depleted by sterile females rather than the relatively
rare wild females. Here, we demonstrate that providing yeast hydrolysate for 48 h after adult
emergence, emulating the current pre-release holding period of Q-fly SIT, leads to a significant
increase in reproductive development and sexual performance inmale Q-flies. In contrast, female Qflies
with access to yeast hydrolysate for 48 h had ovaries that were poorly developed and, particularly
at younger ages, were less likely to mate and remate than females with continuous, ad libitum access
to yeast hydrolysate. Our findings suggest that addition of yeast hydrolysate into the pre-release diet
of Q-flies could be a cost-effective means of releasing a bisexual strain with competitive males but
with sexually immature females, thereby rendering it operationallymore similar to a unisexual strain
Practicing Imperfect Forgiveness
Forgiveness is typically regarded as a good thing - even a virtue - but acts of forgiveness can vary widely in value, depending on their context and motivation. Faced with this variation, philosophers have tended to reinforce everyday concepts of forgiveness with strict sets of conditions, creating ideals or paradigms of forgiveness. These are meant to distinguish good or praiseworthy instances of forgiveness from problematic instances and, in particular, to protect the self-respect of would-be forgivers. But paradigmatic forgiveness is problematic for a number of reasons, including its inattention to forgiveness as a gendered trait. We can account for the values and the risks associated with forgiving far better if we treat it as a moral practice and not an ideal
Recommended from our members
Compulsators: Principles and Applications
The authors discuss work being done on reducing and tailoring generator internal impedances in order to maximise their transient response. The work is taking place at the centre for Electromechanics at The University of Texas at Austin (CEM-UT). The resulting pulsed generators draw on the energy stored kinetically in the rotor inertia to generate extremely high power levels for short periods of time. Two classes of pulsed generators have been developed at CEM-UT: homopolar generators (single pulse) and compensated pulsed alternators or compulsators (repetitively pulsed). The authors discuss the developments of these two types of pulsed generators at CEM-UT and their principles and applicationsCenter for Electromechanic
Time-course for attainment and reversal of acclimation to constant temperature in two Ceratitis species
Acclimation in the thermal tolerance range of insects occurs when they are exposed to novel temperatures in the laboratory. In contrast to the large number of studies that have tested for the ability of insects to acclimate, relatively few have sought to determine the time-course for attainment and reversal of thermal acclimation. In this study the time required for the Mediterranean fruit fly, Ceratitis capitata Wiedemann, and the Natal fruit fly, Ceratitis rosa Karsch, to acclimate to a range of constant temperatures was tested by determining the chill-coma recovery time and heat knock-down time of flies that had been exposed to novel benign temperatures for different durations. The time required for reversal of acclimation for both Ceratitis species was also determined after flies had been returned to the control temperature. Acclimation to 31 °C for only one day significantly improved the heat knock-down time of C. capitata, but also led to slower recovery from chill-coma. Heat knock-down time indicated that acclimation was achieved after only one day in C. rosa, but it took three days for C. rosa to exhibit a significant acclimation response to a novel temperature of 33 °C when measured using chill-coma recovery time. Reversal of acclimation after return to initial temperature conditions was achieved after only one day in both C. capitata and C. rosa. Adult C. capitata held at 31.5 °C initially exhibited improved heat knock-down times but after 9 days the heat knock-down time of these flies had declined to levels not significantly different from that of control flies held at the baseline temperature of 24 °C. In both Ceratitis species, heat knock-down time declined with age whereas chill-coma recovery time increased with age, indicating an increased susceptibility to high and low temperatures, respectively. © 2011 Elsevier Ltd. All rights reserved.Article in Pres
Marking Bactrocera dorsalis
Daylight fluorescent pigment powders are frequently used to self-mark tephritid flies that
are released in sterile insect technique programmes and for studies on their population
ecology, movement and behaviour. This study was conducted to determine the effects of
pigment colour and dose in marking the Oriental fruit fly, Bactrocera dorsalis (Hendel)
(Diptera: Tephritidae). Six pigment colours (Astral Pink 1, Blaze 5, Stellar Green 8, Lunar
Yellow 27, Comet Blue 60 and Invisible Blue 70) were applied to pupae at doses of 0, 2, 4, or
6 g/l. Under laboratory conditions, pigment colour had a small but significant effect on the
number of partially emerged and deformed adults; the fewest of these were observed when
flies were marked with Astral Pink 1. Pigment concentration, on the other hand, had no
effect on adult emergence, partial emergence, deformed adults and mortality on the last day
of eclosion. There was no significant effect of pigment colour on adult survival under laboratory
and semi-field conditions. Under laboratory conditions, however, there was an effect of
pigment concentration on adult survival depending on pigment colour. Visibility under an
ultraviolet light and persistence of marks was significantly affected by pigment colour and
concentration when observed under laboratory conditions, but not under semi-field conditions.
Regardless of colour or dose, pigments used in the study were visible for at least 14
days, but began to fade by 21 days after adult eclosion. To mark B. dorsalis under temperate,
warmsummer African conditions, all pigment colours tested in this study may be applied at
2–4 g/l pupae. Recaptures ofmarkedandreleased fliesmaybe underestimated as the flies age.Citrus Research International
(project 1075), Hortgro Science, and the
South African Table Grape Industry as well as the The South
African Government through its Technology and
Human Resources for Industry Programme(THRIP;
project TP1207132909).http://www.journals.co.za/content/journal/entohttp://www.entsocsa.co.za/Publications.htmam2017Zoology and Entomolog
Sex differences in developmental response to yeast hydrolysate supplements in adult Queensland fruit fly
Please help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]