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Creators/Authors contains: "O’Donnell, D"

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  1. null (Ed.)
    Recent research has shown an association between monthly law enforcement drug seizure events and accidental drug overdose deaths using cross-sectional data in a single state, whereby increased seizures correlated with more deaths. In this study, we conduct statistical analysis of street-level data on law enforcement drug seizures, along with street-level data on fatal and non-fatal overdose events, to determine possible micro-level causal associations between opioid-related drug seizures and overdoses. For this purpose, we introduce a novel, modified two-process Knox test that controls for self-excitation to measure clustering of overdoses nearby in space and time following law enforcement seizures. We observe a small, but statistically significant ( p  < 0.001), effect of 17.7 excess non-fatal overdoses per 1000 law enforcement seizures within three weeks and 250 m of a seizure. We discuss the potential causal mechanism for this association along with policy implications. 
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  2. Abstract The electricE1 and magneticM1 dipole responses of the$$N=Z$$ N = Z nucleus$$^{24}$$ 24 Mg were investigated in an inelastic photon scattering experiment. The 13.0 MeV electrons, which were used to produce the unpolarised bremsstrahlung in the entrance channel of the$$^{24}$$ 24 Mg($$\gamma ,\gamma ^{\prime }$$ γ , γ ) reaction, were delivered by the ELBE accelerator of the Helmholtz-Zentrum Dresden-Rossendorf. The collimated bremsstrahlung photons excited one$$J^{\pi }=1^-$$ J π = 1 - , four$$J^{\pi }=1^+$$ J π = 1 + , and six$$J^{\pi }=2^+$$ J π = 2 + states in$$^{24}$$ 24 Mg. De-excitation$$\gamma $$ γ rays were detected using the four high-purity germanium detectors of the$$\gamma $$ γ ELBE setup, which is dedicated to nuclear resonance fluorescence experiments. In the energy region up to 13.0 MeV a total$$B(M1)\uparrow = 2.7(3)~\mu _N^2$$ B ( M 1 ) = 2.7 ( 3 ) μ N 2 is observed, but this$$N=Z$$ N = Z nucleus exhibits only marginalE1 strength of less than$$\sum B(E1)\uparrow \le 0.61 \times 10^{-3}$$ B ( E 1 ) 0.61 × 10 - 3  e$$^2 \, $$ 2 fm$$^2$$ 2 . The$$B(\varPi 1, 1^{\pi }_i \rightarrow 2^+_1)/B(\varPi 1, 1^{\pi }_i \rightarrow 0^+_{gs})$$ B ( Π 1 , 1 i π 2 1 + ) / B ( Π 1 , 1 i π 0 gs + ) branching ratios in combination with the expected results from the Alaga rules demonstrate thatKis a good approximative quantum number for$$^{24}$$ 24 Mg. The use of the known$$\rho ^2(E0, 0^+_2 \rightarrow 0^+_{gs})$$ ρ 2 ( E 0 , 0 2 + 0 gs + ) strength and the measured$$B(M1, 1^+ \rightarrow 0^+_2)/B(M1, 1^+ \rightarrow 0^+_{gs})$$ B ( M 1 , 1 + 0 2 + ) / B ( M 1 , 1 + 0 gs + ) branching ratio of the 10.712 MeV$$1^+$$ 1 + level allows, in a two-state mixing model, an extraction of the difference$$\varDelta \beta _2^2$$ Δ β 2 2 between the prolate ground-state structure and shape-coexisting superdeformed structure built upon the 6432-keV$$0^+_2$$ 0 2 + level. 
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