Masses and Interactions of q-Fermionic Knots

The q-electroweak theory suggests a description of elementary particles as solitons labelled by the irreducible representations of SU_q(2). Since knots may also be labelled by the irreducible representations of SU_q(2), we study a model of elementary particles based on a one-to-one correspondence between the four families of Fermions (leptons, neutrinos, (-1/3) quarks, (2/3) quarks) and the four simplest knots (trefoils). In this model the three particles of each family are identified with the ground and first two excited states of their common trefoil. Guided by the standard electroweak theory we calculate conditions restricting the masses of the fermions and the interactions between them. In its present form the model predicts a fourth generation of fermions as well as a neutrino spectrum. The same model with q almost equal to 1 is compatible with the Kobayashi-Maskawa matrix. Depending on the test of these predictions, the model may be refined.Comment: 40 pages, 2 figures, latex forma

The Female Perspective of Mating in A. femoralis, a Territorial Frog with Paternal Care – A Spatial and Genetic Analysis

The adaptive significance of sequential polyandry is a challenging question in evolutionary and behavioral biology. Costs and benefits of different mating patterns are shaped by the spatial distribution of individuals and by genetic parameters such as the pairwise relatedness between potential mating partners. Thus, females should become less choosy as costs of mating and searching for mates increase. We used parentage assignments to investigate spatial and genetic patterns of mating across a natural population of the Neotropical frog Allobates femoralis, a species characterized by male territoriality and care and female iteroparity. There was no correlation between genetic and spatial distances between adult individuals across the population. In 72% of cases, females mated with males available within a radius of 20 m. Mean pairwise relatedness coefficients of successful reproducers did not differ from random mating but had a lower variance than expected by chance, suggesting maximal reproductive output at intermediate genetic divergence. We also found evidence for selection in favor of more heterozygous individuals between the embryo and adult stage. The level of sequential polyandry significantly increased with the number of spatially available males. Females that had more candidate males also produced more adult progeny. We hypothesize that the benefits associated with female multiple mating outweigh the costs of in- and outbreeding depression, and consequently precluded the evolution of ‘choosy’ mate selection in this species

Acoustic orientation in the great crested newt (Triturus cristatus)

We carried out laboratory experiments to determine whether orientation during migration in the great crested newt (Triturus cristatus) is influenced by acoustic information. Newts retrieved during the aquatic breeding seasons (adults), as well as during the terrestrial phase after breeding (adults and juveniles), were subjected to calls from sympatric (Rana temporaria and Bufo bufo) and allopatric (Lithobates catesbeianus) anurans. In addition to natural stimuli, we also used modified anuran calls (continuous sound with inter-note intervals removed), white noise with and without envelop, and a heterochthonous sound (pile driving). In a circular arena, adult newts retrieved both during their aquatic and terrestrial phase orientated towards the B. bufo stimulus, and migrated at random directions when exposed to the other calls; the lack of orientation towards the sympatric R. temporaria parallels a largely non-overlapping breeding season. Inexperienced juveniles did not orientate towards anuran calls, suggesting that phonotactic responses could be learned. Both aquatic as well as terrestrial adults significantly moved away from a white noise envelop. The results suggest different degrees of heterospecific call attraction across life stages, and provide evidence that unnatural sound might have an adverse effect on breeding migrations

Robust excitation of C-band quantum dots for quantum communication

Building a quantum internet requires efficient and reliable quantum hardware, from photonic sources to quantum repeaters and detectors, ideally operating at telecommunication wavelengths. Thanks to their high brightness and single-photon purity, quantum dot (QD) sources hold the promise to achieve high communication rates for quantum-secured network applications. Furthermore, it was recently shown that excitation schemes, such as longitudinal acoustic phonon-assisted (LA) pumping, provide security benefits by scrambling the coherence between the emitted photon-number states. In this work, we investigate further advantages of LA-pumped quantum dots with emission in the telecom C-band as a core hardware component of the quantum internet. We experimentally demonstrate how varying the pump energy and spectral detuning with respect to the excitonic transition can improve quantum-secured communication rates and provide stable emission statistics regardless of network-environment fluctuations. These findings have significant implications for general implementations of QD single-photon sources in practical quantum communication networks

An experimental assessment of detection dog ability to locate great crested newts ( Triturus cristatus ) at distance and through soil

Detection dogs are increasingly used to locate cryptic wildlife species, but their use for amphibians is still rather underexplored. In the present paper we focus on the great crested newt (Triturus cristatus), a European species which is experiencing high conservation concerns across its range, and assess the ability of a trained detection dog to locate individuals during their terrestrial phase. More specifically, we used a series of experiments to document whether a range of distances between target newts and the detection dog (odour channelled through pipes 68 mm in diameter) affects the localisation, and to assess the ability and efficiency of target newt detection in simulated subterranean refugia through 200 mm of two common soil types (clay and sandy soil, both with and without air vents to mimic mammal burrows, a common refuge used by T. cristatus). The detection dog accurately located all individual T. cristatus across the entire range of tested distances (0.25 m– 2.0 m). The substrate trials revealed that the detection dog could locate individuals also through soil. Contrary to existing studies with detection dogs in human forensic contexts, however, detection was generally slower for T. cristatus under sandy soil compared to clay soil, particularly when a vent was absent. Our study provides a general baseline for the use of detection dogs in locating T. cristatus and similar amphibian species during their terrestrial phase

An experimental assessment of detection dog ability to locate great crested newts (Triturus cristatus) at distance and through soil

Detection dogs are increasingly used to locate cryptic wildlife species, but their use for amphibians is still rather underexplored. In the present paper we focus on the great crested newt (Triturus cristatus), a European species which is experiencing high conservation concerns across its range, and assess the ability of a trained detection dog to locate individuals during their terrestrial phase. More specifically, we used a series of experiments to document whether a range of distances between target newts and the detection dog (odour channelled through pipes 68 mm in diameter) affects the localisation, and to assess the ability and efficiency of target newt detection in simulated subterranean refugia through 200 mm of two common soil types (clay and sandy soil, both with and without air vents to mimic mammal burrows, a common refuge used by T. cristatus). The detection dog accurately located all individual T. cristatus across the entire range of tested distances (0.25 m-2.0 m). The substrate trials revealed that the detection dog could locate individuals also through soil. Contrary to existing studies with detection dogs in human forensic contexts, however, detection was generally slower for T. cristatus under sandy soil compared to clay soil, particularly when a vent was absent. Our study provides a general baseline for the use of detection dogs in locating T. cristatus and similar amphibian species during their terrestrial phase

Time-bin entanglement at telecom wavelengths from a hybrid photonic integrated circuit

Mass-deployable implementations for quantum communication require compact, reliable, and low-cost hardware solutions for photon generation, control and analysis. We present a fiber-pigtailed hybrid photonic circuit comprising nonlinear waveguides for photon-pair generation and a polymer interposer reaching 68dB of pump suppression and photon separation with >25dB polarization extinction ratio. The optical stability of the hybrid assembly enhances the quality of the entanglement, and the efficient background suppression and photon routing further reduce accidental coincidences. We thus achieve a 96(-8,+3)% concurrence and a 96(-5,+2)% fidelity to a Bell state. The generated telecom-wavelength, time-bin entangled photon pairs are ideally suited for distributing Bell pairs over fiber networks with low dispersion

High Evolutionary Potential Maintained in Common Frog ( Rana temporaria ) Populations Inhabiting Urban Drainage Ponds

Urbanisation leading to habitat change and fragmentation is a recognised global threat to biodiversity. However, it may also offer opportunities for some species. Genetic diversity, one of the three components of biodiversity, is often overlooked in conservation planning and policy. In the present study, we used a panel of seven microsatellite markers to compare the genetic structure of 34 common frog (Rana temporaria) populations residing in urban and suburban drainage ponds in Inverness (Scotland) with populations from rural surroundings. As a main finding, the levels of genetic variation were indiscernible between (sub)urban and rural populations. Significant isolation-by-distance was observed only for rural populations, with measures of pairwise genetic differentiation (Fst) that were, on average, lower than those in urban and suburban areas. The mean numbers of alleles remained stable between two temporal sets of samples collected at intervals broadly representing one R. temporaria generation, but with a tendency of decreasing allelic richness, irrespectively of the site characteristics. Taking these results together, our study revealed that the elevated levels of differentiation between R. temporaria populations inhabiting (sub)urban drainage ponds did not lead to increased levels of genetic erosion. Our findings support the importance of well-designed blue–green infrastructure in urban landscapes for the retention of within-species genetic diversity and can help to inform future biodiversity management policies

The "Peer" in "Peer Review"

Gad Perry1, Jaime Bertoluci2, Bruce Bury3, Robert W. Hansen4, Robert Jehle5, John Measey6, Brad R. Moon7, Erin Muths8, and Marco A. L. Zuffi9,* 1 Texas Tech University, Lubbock, TX, USA; Journal of Herpetology. 2 Universidade de Sao Paulo, Brazil; Phyllomedusa. 3 USGS, Corvallis, OR, USA; Herpetological Conservation and Biology. 4 Clovis, CA, USA; Herpetological Review. 5 University of Salford, Greater Manchester, UK; Herpetological Journal. 6 University of the Western Cape, South Africa; African Journal of Herpetology. 7 University of Louisiana at Lafayette, LA, USA; Herpetologica. 8 USGS, Fort Collins, CO, USA; Journal of Herpetology. 9 Museum Natural History, University of Pisa, Italy; Acta Herpetologica

Nuclear factor κB-inducing kinase activation as a mechanism of pancreatic β cell failure in obesity

The nuclear factor κB (NF-κB) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic β cell dysfunction in the metabolic syndrome. Whereas canonical NF-κB signaling is well studied, there is little information on the divergent noncanonical NF-κB pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-κB-inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of β cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-κB components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive β cell-intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to β cell failure. These studies reveal that NIK contributes a central mechanism for β cell failure in diet-induced obesity