1,813 research outputs found
Banded mongooses avoid inbreeding when mating with members of the same natal group
Inbreeding and inbreeding avoidance are key factors in the evolution of animal societies, influencing dispersal and reproductive strategies which can affect relatedness structure and helping behaviours. In cooperative breeding systems, individuals typically avoid inbreeding through reproductive restraint and/or dispersing to breed outside their natal group. However, where groups contain multiple potential mates of varying relatedness, strategies of kin recognition and mate choice may be favoured. Here, we investigate male mate choice and female control of paternity in the banded mongoose (Mungos mungo), a cooperatively-breeding mammal where both sexes are often philopatric and mating between relatives is known to occur. We find evidence suggestive of inbreeding depression in banded mongooses, indicative of a benefit to avoiding breeding with relatives. Successfully breeding pairs were less related than expected under random mating, which appeared to be driven by both male choice and female control of paternity. Male banded mongooses actively guard females to gain access to mating opportunities, and this guarding behaviour is preferentially directed towards less closely related females. Guard-female relatedness did not affect the guard’s probability of gaining reproductive success. However, where mate-guards are unsuccessful they lose paternity to males that are less related to the females than themselves. Together our results suggest that both sexes of banded mongoose use kin discrimination to avoid inbreeding. Although this strategy appears to be rare among cooperative breeders, it may be more prominent in species where relatedness to potential mates is variable, and/or where opportunities for dispersal and mating outside of the group are limited
Towards a 4d/2d correspondence for Sicilian quivers
We study the 4d/2d AGT correspondence between four-dimensional instanton
counting and two-dimensional conformal blocks for generalized SU(2) quiver
gauge theories coming from punctured Gaiotto curves of arbitrary genus. We
propose a conformal block description that corresponds to the elementary SU(2)
trifundamental half-hypermultiplet, and check it against Sp(1)-SO(4) instanton
counting.Comment: 39 pages, 11 figure
Counting Exceptional Instantons
We show how to obtain the instanton partition function of N=2 SYM with
exceptional gauge group EFG using blow-up recursion relations derived by
Nakajima and Yoshioka. We compute the two instanton contribution and match it
with the recent proposal for the superconformal index of rank 2 SCFTs with E6,
E7 global symmetry.Comment: 16 pages, references adde
Bootstrapping the superconformal index with surface defects
The analytic properties of the N = 2 superconformal index are given a
physical interpretation in terms of certain BPS surface defects, which arise as
the IR limit of supersymmetric vortices. The residue of the index at a pole in
flavor fugacity is interpreted as the index of a superconformal field theory
without this flavor symmetry, but endowed with an additional surface defect.
The residue can be efficiently extracted by acting on the index with a
difference operator of Ruijsenaars-Schneider type. By imposing the
associativity constraints of S-duality, we are then able to evaluate the index
of all generalized quiver theories of type A, for generic values of the three
superconformal fugacities, with or without surface defects.Comment: 60 pages, 7 figure
Energy- and flux-budget (EFB) turbulence closure model for the stably stratified flows. Part I: Steady-state, homogeneous regimes
We propose a new turbulence closure model based on the budget equations for
the key second moments: turbulent kinetic and potential energies: TKE and TPE
(comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent
fluxes of momentum and buoyancy (proportional to potential temperature).
Besides the concept of TTE, we take into account the non-gradient correction to
the traditional buoyancy flux formulation. The proposed model grants the
existence of turbulence at any gradient Richardson number, Ri. Instead of its
critical value separating - as usually assumed - the turbulent and the laminar
regimes, it reveals a transition interval, 0.1< Ri <1, which separates two
regimes of essentially different nature but both turbulent: strong turbulence
at Ri<<1; and weak turbulence, capable of transporting momentum but much less
efficient in transporting heat, at Ri>1. Predictions from this model are
consistent with available data from atmospheric and lab experiments, direct
numerical simulation (DNS) and large-eddy simulation (LES).Comment: 40 pages, 6 figures, Boundary-layer Meteorology, resubmitted, revised
versio
Soil-atmosphere exchange of nitrous oxide, methane and carbon dioxide in a gradient of elevation in the coastal Brazilian Atlantic forest
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Soils of tropical forests are important to the global budgets of greenhouse gases. The Brazilian Atlantic Forest is the second largest tropical moist forest area of South America, after the vast Amazonian domain. This study aimed to investigate the emissions of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) fluxes along an altitudinal transect and the relation between these fluxes and other climatic, edaphic and biological variables (temperature, fine roots, litterfall, and soil moisture). Annual means of N2O flux were 3.9 (+/- 0.4), 1.0 (+/- 0.1), and 0.9 (+/- 0.2) ng N cm(-2) h(-1) at altitudes 100, 400, and 1000 m, respectively. On an annual basis, soils consumed CH4 at all altitudes with annual means of -1.0 (+/- 0.2), -1.8 (+/- 0.3), and -1.6 (+/- 0.1) mg m(-2) d(-1) at 100 m, 400 m and 1000 m, respectively. Estimated mean annual fluxes of CO2 were 3.5, 3.6, and 3.4 mu mol m(-2) s(-1) at altitudes 100, 400 and 1000 m, respectively. N2O fluxes were significantly influenced by soil moisture and temperature. Soil-atmosphere exchange of CH4 responded to changes in soil moisture. Carbon dioxide emissions were strongly influenced by soil temperature. While the temperature gradient observed at our sites is only an imperfect proxy for climatic warming, our results suggest that an increase in air and soil temperatures may result in increases in decomposition rates and gross inorganic nitrogen fluxes that could support consequent increases in soil N2O and CO2 emissions and soil CH4 consumption.83733742Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2005/57549-8]FAPESP [FAPESP 03/12595-7
Vortex counting from field theory
The vortex partition function in 2d N = (2,2) U(N) gauge theory is derived
from the field theoretical point of view by using the moduli matrix approach.
The character for the tangent space at each moduli space fixed point is written
in terms of the moduli matrix, and then the vortex partition function is
obtained by applying the localization formula. We find that dealing with the
fermionic zero modes is crucial to obtain the vortex partition function with
the anti-fundamental and adjoint matters in addition to the fundamental chiral
multiplets. The orbifold vortex partition function is also investigated from
the field theoretical point of view.Comment: 21 pages, no figure
Introduction to the functional RG and applications to gauge theories
These lectures contain an introduction to modern renormalization group (RG)
methods as well as functional RG approaches to gauge theories. In the first
lecture, the functional renormalization group is introduced with a focus on the
flow equation for the effective average action. The second lecture is devoted
to a discussion of flow equations and symmetries in general, and flow equations
and gauge symmetries in particular. The third lecture deals with the flow
equation in the background formalism which is particularly convenient for
analytical computations of truncated flows. The fourth lecture concentrates on
the transition from microscopic to macroscopic degrees of freedom; even though
this is discussed here in the language and the context of QCD, the developed
formalism is much more general and will be useful also for other systems.Comment: 60 pages, 14 figures, Lectures held at the 2006 ECT* School
"Renormalization Group and Effective Field Theory Approaches to Many-Body
Systems", Trento, Ital
Selection for Heterozygosity Gives Hope to a Wild Population of Inbred Wolves
Recent analyses have questioned the usefulness of heterozygosity estimates as measures of the inbreeding coefficient (f), a finding that may have dramatic consequences for the management of endangered populations. We confirm that f and heterozygosity is poorly correlated in a wild and highly inbred wolf population. Yet, our data show that for each level of f, it was the most heterozygous wolves that established themselves as breeders, a selection process that seems to have decelerated the loss of heterozygosity in the population despite a steady increase of f. The markers contributing to the positive relationship between heterozygosity and breeding success were found to be located on different chromosomes, but there was a substantial amount of linkage disequilibrium in the population, indicating that the markers are reflecting heterozygosity over relatively wide genomic regions. Following our results we recommend that management programs of endangered populations include estimates of both f and heterozygosity, as they may contribute with complementary information about population viability
Glatiramer Acetate Treatment Normalizes Deregulated microRNA Expression in Relapsing Remitting Multiple Sclerosis
The expression of selected microRNAs (miRNAs) known to be involved in the regulation of immune responses was analyzed in 74 patients with relapsing remitting multiple sclerosis (RRMS) and 32 healthy controls. Four miRNAs (miR-326, miR-155, miR-146a, miR-142-3p) were aberrantly expressed in peripheral blood mononuclear cells from RRMS patients compared to controls. Although expression of these selected miRNAs did not differ between treatment-naïve (n = 36) and interferon-beta treated RRMS patients (n = 18), expression of miR-146a and miR-142-3p was significantly lower in glatiramer acetate (GA) treated RRMS patients (n = 20) suggesting that GA, at least in part, restores the expression of deregulated miRNAs in MS
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