697 research outputs found
Stepfamily Instability in Germany
Separations exert a detrimental impact on different areas of life in both adults and children. Having already experienced family instability, stepfamily members are at risk of experiencing even multiple family separations across the life course. To better understand stepfamily (in)stability in Europe, we study stability risks and facilitators between stepfamilies in Germany. We pursue Cherlin's perspective of stepfamilies' destabilizing lack of institutionalization. Specifically, we assess the impact of social control in terms of social and legislative conditions, (step)parents' social roles in terms of gender roles, and customs and conventions of family life in terms of union status. We apply event history analysis to a sample of 2,166 stepfamilies, 543 of which end up separated, from the German National Educational Panel Study (NEPS). For example, we find that social and legislative liberalization might destabilize stepfamilies if it eases leaving unhappy relationships, and might stabilize stepfamilies if it alleviates stepfamilies' financial or caregiving burdens through de-familiarization. In contrast to stepfather families, stepmother families' stability appears to profit from stepmothers' and biological fathers' investment in stepfamily relationships to make up for noncomplying with gendered social roles. Overall, stepfamily stability appears to benefit from individual as well as societal pursuits of re-institutionalization
Alpha and beta diversity patterns of macro-moths reveal a breakpoint along a latitudinal gradient in Mongolia
Little is known about the diversity and distribution patterns of moths along latitudinal gradients. We studied macro-moths in Mongolia along an 860Â km latitudinal climatic gradient to gain knowledge on community composition, alpha, beta, and gamma diversity as well as underlying factors, which can be used as baseline information for further studies related to climate change. We identified 236 species of moths of ten families. Our study shows that the diversity of moths increased with the latitude, i.e., low species richness in the south and higher richness in the north. Moth community composition changed along the gradient, and we revealed a breakpoint of beta diversity that divided grassland and desert communities. In the desert, beta diversity was driven by species loss (i.e., nestedness), and few tolerant species existed with high abundance. In contrast, in the grassland, beta diversity was driven by species replacement with more unique species, (i.e., species which occurred only in one site). We found the lowest species diversity in the transitional zones dominated by few generalist species such as Agrotis ripae and Anarta trifolii. Low precipitation and an increasing number of grazing goats are drivers of species loss. We suggest different conservation strategies regarding the contrasting patterns of beta diversity in desert and grassland
Probing the Tavis-Cummings level splitting with intermediate-scale superconducting circuits
We demonstrate the local control of up to eight two-level systems interacting
strongly with a microwave cavity. Following calibration, the frequency of each
individual two-level system (qubit) is tunable without influencing the others.
Bringing the qubits one by one on resonance with the cavity, we observe the
collective coupling strength of the qubit ensemble. The splitting scales up
with the square root of the number of the qubits, which is the hallmark of the
Tavis-Cummings model. The local control circuitry causes a bypass shunting the
resonator, and a Fano interference in the microwave readout, whose contribution
can be calibrated away to recover the pure cavity spectrum. The simulator's
attainable size of dressed states with up to five qubits is limited by reduced
signal visibility, and -- if uncalibrated -- by off-resonance shifts of
sub-components. Our work demonstrates control and readout of quantum coherent
mesoscopic multi-qubit system of intermediate scale under conditions of noise
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Switching between Proton Vacancy and Excess Proton Transfer Pathways in the Reaction between 7-Hydroxyquinoline and Formate
Bifunctional or amphoteric photoacids simultaneously present donor (acidic) and acceptor (basic) properties making them useful tools to analyze proton transfer reactions. In protic solvents, the proton exchange between the acid and the base is controlled by the acidity or basicity strength and typically occurs on two different pathways known as protolysis and hydrolysis. We report here how the addition of a formate base will alter the relative importance of the possible reaction pathways of the bifunctional photoacid 7-hydroxyquinoline (7HQ), which has been recently understood to predominantly involve a hydroxide/methoxide transport mechanism between the basic proton-accepting quinoline nitrogen site toward the proton-donating OH group with a time constant of 360 ps in deuterated methanol (CD3OD). We follow the reaction dynamics by probing the IR-active marker modes of the different charged forms of photoexcited 7HQ, and of formic acid (HCOOD) in CD3OD solution. A comparison of the transient IR spectra as a function of formate concentration, and classical molecular dynamics simulations enables us to identify distinct contributions of “tight” (meaning “contact”) and “loose” (i.e., “solvent-separated”) 7HQ–formate reaction pairs in our data. Our results suggest that depending on the orientation of the OH group with respect to the quinoline aromatic ring system, the presence of the formate molecule in a proton relay pathway facilitates a net proton transfer from the proton-donating OH group of 7HQ-N* via the methanol/formate bridge toward the quinoline N site
Quantum emulation of the transient dynamics in the multistate Landau-Zener model
Quantum simulation is one of the most promising near term applications of quantum computing. Especially, systems with a large Hilbert space are hard to solve for classical computers and thus ideal targets for a simulation with quantum hardware. In this work, we study experimentally the transient dynamics in the multistate Landau-Zener model as a function of the Landau-Zener velocity. The underlying Hamiltonian is emulated by superconducting quantum circuit, where a tunable transmon qubit is coupled to a bosonic mode ensemble comprising four lumped element microwave resonators. We investigate the model for different initial states: Due to our circuit design, we are not limited to merely exciting the qubit, but can also pump the harmonic modes via a dedicated drive line. Here, the nature of the transient dynamics depends on the average photon number in the excited resonator. The greater effective coupling strength between qubit and higher Fock states results in a quasi-adiabatic transition, where coherent quantum oscillations are suppressed without the introduction of additional loss channels. Our experiments pave the way for more complex simulations with qubits coupled to an engineered bosonic mode spectrum
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