SU(2)-in-SU(1,1) Nested Interferometer for Highly Sensitive, Loss-Tolerant Quantum Metrology

We present experimental and theoretical results on a new interferometer topology that nests a SU(2) interferometer, e.g., a Mach-Zehnder or Michelson interferometer, inside a SU(1,1) interferometer, i.e., a Mach-Zehnder interferometer with parametric amplifiers in place of beam splitters. This SU(2)-in-SU(1,1) nested interferometer (SISNI) simultaneously achieves high signal-to-noise ratio (SNR), sensitivity beyond the standard quantum limit (SQL) and tolerance to photon losses external to the interferometer, e.g., in detectors. We implement a SISNI using parametric amplification by four-wave mixing (FWM) in Rb vapor and a laser-fed Mach-Zehnder SU(2) interferometer. We observe path-length sensitivity with SNR 2.2 dB beyond the SQL at power levels (and thus SNR) 2 orders of magnitude beyond those of previous loss-tolerant interferometers. We find experimentally the optimal FWM gains and find agreement with a minimal quantum noise model for the FWM process. The results suggest ways to boost the in-practice sensitivity of high-power interferometers, e.g., gravitational wave interferometers, and may enable high-sensitivity, quantum-enhanced interferometry at wavelengths for which efficient detectors are not available.Comment: 6 pages + 4 of supplemental material, 5 figure

Održivost i odgovornost potrošača: poslije zelene i etičke potrošnje

Purpose – Most literature regarding sustainable behavior is based on the assumption that the reduction of consumption is inherently positive (mainly in the form of positive environmental consequences) and based on ethical considerations. However, the issue of the social consequences of this reduction and self-interested intentions in consumption is not generally open to debate. This paper aims to identify dimensions of sustainable and responsible consumer behavior, distinguish between the two concepts, and present consumer obstacles to acting responsibly in all aspects that a sustainability agenda would suggest. Design/Methodology/Approach – The paper includes a literature review, proposes a framework of responsible and sustainable consumption (RSCB), and offers a set of propositions to achieve responsible and sustainable consumption. Insights from personal interviews with consumers are added for the sake of additional understanding of the concepts presented. Findings and implications – Through the RSCB framework, we show the potential trade-off decisions consumers have to make in order to implement sustainability and responsibility issues in everyday consumer decision processes. Struggles between doing what is good for them and what is good for the environment and society could be a reason why consumers have difficulties achieving responsible and sustainable consumption. Limitations – Qualitative study based on a small sample of personal interviews does not allow for generalizations. Originality – A research gap in understanding the dimensions of sustainable and responsible consumer actions in terms of their emphasis (environmental and social) and intentions (self-interest and other-interest) is addressed. By understanding those two dimensions of behavior, managers and consumers can resolve consumer sustainability and responsibility dilemmas that arise from a one-dimensional view in order to move sustainability research and practice forward.Svrha – Većina se literature o održivom ponašanju zasniva na pretpostavci da je smanjenje potrošnje samo po sebi pozitivno (uglavnom zbog pozitivnih posljedica na okoliš) i temeljeno na etičkim razmatranjima. Međutim, pitanje o društvenim posljedicama tog smanjenja i namjerama iz vlastitog interesa, općenito nije otvoreno za raspravu. Cilj rada jest identificirati dimenzije održivog i odgovornog ponašanja potrošača, razlikovati ta dva koncepta i predstaviti prepreke za odgovorno djelovanje potrošača u svim aspektima koji bi se mogli odnositi na održivost. Metodološki pristup – Rad uključuje pregled literature, predlaže okvir održive i odgovorne potrošnje te nudi niz prijedloga za postizanje odgovorne i održive potrošnje. Dodani su uvidi iz osobnih intervjua s potrošačima radi boljeg razumijevanja prikazanih koncepata. Rezultati i implikacije – Kroz predloženi okvir pokazujemo potencijalne kompromisne odluke potrošača koje oni trebaju donijeti kako bi implementirali održiva i odgovorna pitanja u svakodnevnom procesu odlučivanja. Borbe između onoga što je dobro za njih i što je dobro za okoliš i društvo, mogle bi biti razlogom zašto potrošači imaju problema u postizanju odgovorne i održive potrošnje. Ograničenja – Kvalitativno istraživanje temeljeno na malom uzorku osobnih intervjua ne dozvoljava poopćavanje. Doprinos – Adresiran je istraživački jaz u razumijevanju dimenzija održivog i odgovornog djelovanja potrošača u pogledu naglašavanja (okoliša i društva) te namjera (vlastitog interesa i interesa drugih). Razumijevanjem tih dviju dimenzija ponašanja, menadžeri i potrošači mogu riješiti potrošačeve dileme o održivosti i odgovornosti koje proizlaze iz jednodimenzionalnog pogleda te unaprijediti istraživanja i praksu održivosti

Silicic ash beds bracket Emeishan Large Igneous Province to < 1 m.y. at ~ 260 Ma

This research was supported by the Open Fund (PLC201404) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology), the National Natural Science Foundation of China (41502109), Project funded by China Postdoctoral Science Foundation (2015 M582528) and the Fundamental Research Funds for the Central Universities, Chengdu University of Technology.Claystone beds directly below and above the Emeishan basalts in SW China formed around the Guadalupian-Lopingian (G-L) boundary. Zircons from both levels give U–Pb ages of ~ 260 Ma, and are identical within-error to ages reported for the Emeishan Large Igneous Province (LIP). The claystones lack Nb-Ta anomalies on primitive mantle normalized elemental diagrams; zircons from these claystones have a geochemical affinity to within-plate-type magmas. These features, combined with the strong negative Eu anomalies in the zircons and high Al2O3/TiO2 ratios, indicate that claystones around the G-L boundary have a silicic volcanic component related to Emeishan LIP. Zircons from the underlying claystone bed have much higher U/Yb and Th/Nb ratios and lower εHf(t) values than those overlying the LIP, suggesting that early-stage silicic volcanic rocks had a higher crustal contamination or assimilation during magmatic processes. In terms of stratigraphic correlation, our data demonstrate that silicic eruptions occurred not only at the end, but also at the beginning of the Emeishan LIP, and the overall duration of the main basaltic phase was short (< 1 m.y).PostprintPeer reviewe

An integrated neuroimaging-omics approach for the gut-brain communication pathways in Alzheimer’s disease

A key role of the gut microbiota in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD), has been identified over the past decades. Increasing clinical and preclinical evidence implicates that there is bidirectional communication between the gut microbiota and the central nervous system (CNS), which is also known as the microbiota-gut-brain axis. Nevertheless, current knowledge on the interplay between gut microbiota and the brain remains largely unclear. One of the primary mediating factors by which the gut microbiota interacts with the host is peripheral metabolites, including blood or gut-derived metabolites. However, mechanistic knowledge about the effect of the microbiome and metabolome signaling on the brain is limited. Neuroimaging techniques, such as multi-modal magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET), have the potential to directly elucidate brain structural and functional changes corresponding with alterations of the gut microbiota and peripheral metabolites in vivo. Employing a combination of gut microbiota, metabolome, and advanced neuroimaging techniques provides a future perspective in illustrating the microbiota-gut-brain pathway and further unveiling potential therapeutic targets for AD treatments

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson {\it et al.} [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fan-like electron outflow region including three well-collimated electron jets appears. The ($>1$ MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS