Parity Symmetry in QED3

Schwinger-Dyson equations are used to study spontaneous chiral and parity symmetry breaking of three dimensional quantum electrodynamics with two-component fermions. This theory admits a topological photon mass that explicitly breaks parity symmetry and generates a fermion mass. We show that the pattern of symmetry breaking maintains parity but breaks chiral symmetry. We also find that chiral symmetry is restored at a critical number of fermion flavours in our truncation scheme. The Coleman-Hill theorem is used to demonstrate that the results are reasonably accurate.Comment: 11 pages, 5 figure

Simple Non-Markovian Microscopic Models for the Depolarizing Channel of a Single Qubit

The archetypal one-qubit noisy channels ---depolarizing, phase-damping and amplitude-damping channels--- describe both Markovian and non-Markovian evolution. Simple microscopic models for the depolarizing channel, both classical and quantum, are considered. Microscopic models which describe phase damping and amplitude damping channels are briefly reviewed.Comment: 13 pages, 2 figures. Title corrected. Paper rewritten. Added references. Some typos and errors corrected. Author adde

Mitochondrial heteroplasmy in an avian hybrid form (Passer italiae: Aves, Passeriformes)

Mitochondrial heteroplasmy is the result from biparental transmission of mitochondrial DNA (mtDNA) to the offspring. In such rare cases, maternal and paternal mtDNA is present in the same individual. Though recent studies suggested that mtDNA heteroplasmy might be more common than previously anticipated, that phenomenon is still poorly documented and was mostly detected in case studies on hybrid populations. The Italian sparrow, Passer italiae is a homoploid hybrid form that occurs all across the Italian Peninsula mostly under strict absence of either of its parent species, the house sparrow (P. domesticus) and the Spanish sparrow (P. hispaniolensis). In this study, we document a new case of mitochondrial heteroplasmy from two island populations of P. italiae (Ustica and Lipari). Our analysis was based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) that allows for a clear distinction between mitochondrial lineages of the two parental species. We amplified and sequenced the mitochondrial ND2 gene with specifically designed primer combinations for each of the two parental species. In two of our study populations, a single individual carried two different ND2 haplotypes from each of the two parental lineages. These findings contribute to current knowledge on the still poorly documented phenomenon of paternal leakage in vertebrates

Beyond the stand: Reviewing landscape fragmentation dynamics on biodiversity and ecosystem services in Southeast Asia

Forest and agriculture landscapes dominate across Southeast Asia. Agricultural systems are highly diverse ranging from traditional swidden and agroforestry, to the more recent intensive industrial oil palm plantations. These management approaches have fabricated distinct fragmented landscapes that could yield significantly varying impacts on biodiversity and ecosystem services. Our systematic styled review compares fragmentation in industrial oil palm (IOP) and smallholder agroforestry (SH) landscapes, and how this influences biodiversity (soil fauna, avifauna, and vegetation) and ecosystem services in Southeast Asia. Two literature searches were carried out capturing fragmentation studies in IOP and SH settings. After devising a selection criteria, we identified relevant studies, assessed the type of landscape metrics used, and synthesized research findings. After screening 2301 studies, 26 passed our selection criteria; avifauna was the most widely studies group for biodiversity outcomes (n=9), and isolation was the most popular landscape measure (n=13). 50% of studies focused on IOP in Malaysia and none focused on IOP in Indonesia despite being the world's largest oil palm producer. We found too few studies on interactions between ecosystem services and landscape dynamics to draw meaningful comparative findings. Studies in SH systems provided cases of well-connected and diverse forest-agriculture mosaics that successfully supported all biodiversity. In IOP landscapes, we found mixed effects, which depended on the dispersal range of species, their adaptive ability along habitat gradients, and how actors managed forest fragments. Land use research is dominated by land use level comparisons, and rarely do studies measure landscape interactions, which is evident in the lack of studies in our review. Few studies addressed more complex, yet important measures, such as the permeability and pattern of the landscape matrix1. Assessing fragmentation processes over time addresses the resilience of landscapes to different agricultural practices1, and the critical threshold that determines the recoverability of forests and biodiversity². Understanding these underlying recovery mechanisms contributes to supporting sustainable restoration efforts and agroforestry intensification programs. The current Southeast Asian trend in which landscapes are moving away from swidden and agroforestry practices to industrial plantations could significantly impact biodiversity and ecosystem health. We recommend the following for future research: i) Greater accountability of landscape metrics in assessing spatial interactions with biodiversity and ecosystem services, particularly in smallholder agroforestry systems, and how this can facilitate integrated management of agricultural landscapes. ii) Review threshold studies in the context of landscape dynamics to increase our understanding of resilience in fragmented landscapes, and what role this has for restoration efforts

Sub-10 nm colloidal lithography for integrated spin-photo-electronic devices

Colloidal lithography [1] is how patterns are reproduced in a variety of natural systems and is used more and more as an efficient fabrication tool in bio-, opto-, and nano-technology. Nanoparticles in the colloid are made to form a mask on a given material surface, which can then be transferred via etching into nano-structures of various sizes, shapes, and patterns [2,3]. Such nanostructures can be used in biology for detecting proteins [4] and DNA [5,6], for producing artificial crystals in photonics [7,8] and GHz oscillators in spin-electronics [9-14]. Scaling of colloidal patterning down to 10-nm and below, dimensions comparable or smaller than the main relaxation lengths in the relevant materials, including metals, is expected to enable a variety of new ballistic transport and photonic devices, such as spin-flip THz lasers [15]. In this work we extend the practice of colloidal lithography to producing large-area, near-ballistic-injection, sub-10 nm point-contact arrays and demonstrate their integration in to spin-photo-electronic devices.Comment: 15 pages, 5 figure