We investigate a paradigmatic model for quantum transport with both nearest-neighbor and infinite-range hopping coupling (independent of the position). Due to long-range homogeneous hopping, a gap ...between the ground state and the excited states can be induced, which is mathematically equivalent to the superconducting gap. In the gapped regime, the dynamics within the excited-state subspace is shielded from long-range hopping, namely it occurs as if long-range hopping would be absent. This is a cooperative phenomenon since shielding is effective over a time scale that diverges with the system size. We named this effect cooperative shielding. We also discuss the consequences of our findings on Anderson localization. Long-range hopping is usually thought to destroy localization due to the fact that it induces an infinite number of resonances. Contrary to this common lore we show that the excited states display strong localized features when shielding is effective even in the regime of strong long-range coupling. A brief discussion on the extension of our results to generic power-law decaying long-range hopping is also given. Our preliminary results confirm that the effects found for the infinite-range case are generic.
Black women's sexual harassment is often overlooked and dismissed relative to White women's harassment. In three pre-registered experiments, we test whether this neglect extends to bystander ...intervention in sexual harassment. Participants observed an ostensibly live job interview between a man manager and a Black or White woman job candidate. The manager's questions were pre-programmed to grow increasingly harassing, and participants were asked to intervene if/when they found the interview inappropriate. A meta-analysis of the three studies (N = 1487), revealed that bystanders did not differ in their threshold for intervention when sexual harassment targeted the Black vs. White woman. Despite evidence for the relative neglect of Black women in responses to sexual harassment, these data suggest that bystanders may respond similarly for Black and White women.
Tick-borne encephalitis (TBE) is one of the most important viral infections of the human central nervous system. Approximately 10,000 cases of TBE are referred to hospitals in Europe and Asia each ...year. The TBE virus (TBEV) is mainly transmitted by tick bites but also occasionally by unpasteurized goat's milk. As in endemic areas on average only 1-3 % of ticks are infected with the TBEV and the clinical manifestation rate is approximately 33 %, only approximately 1 in every 100-300 tick bites leads to disease. The incubation period varies from 5-28 days and typically has a biphasic course of fever. The TBE manifests as meningitis in approximately 50 % of patients, as meningoencephalitis in 40 % and as encephalomyelitis in 10 %. The suspected diagnosis is confirmed by the demonstration of TBEV-specific IgM and IgG antibodies in serum and the presence of elevated cell counts in cerebrospinal fluid. No specific treatment for TBE is known but it can be successfully prevented by active immunization.
We report the detection of two isomers of ethynyl cyclopentadiene (
c
-C
5
H
5
CCH), namely 1- and 2-ethynyl-1,3-cyclopentadiene, in the direction of TMC-1. We derive column densities of (1.4 ± 0.2) ...× 10
12
cm
−2
and (2.0 ± 0.4) × 10
12
cm
−2
, respectively, for these two cyclopentadiene derivatives, which imply that they are about ten times less abundant than cyclopentadiene. We also report the tentative detection of ethynyl benzene (C
6
H
5
CCH), for which we estimate a column density of (2.5 ± 0.4) × 10
12
cm
−2
. We derived abundances for the corresponding cyano derivatives of cyclopentadiene and benzene and found values significantly lower than previously reported. The rotational temperature of the ethynyl and cyano derivatives of these cycles is about 9 K, that is, very close to the gas kinetic temperature of the cloud. The abundance ratio of the 1- and 2-isomers of ethynyl cyclopentadiene is 1.4 ± 0.5, while for the two isomers of cyano cyclopentadiene it is 2.4 ± 0.6. The relative abundances of CCH over CN derivatives is 7.7 ± 2.2 for cyclopentadiene, which probably reflects the abundance ratio of the radicals CCH and CN; this ratio is only 2.1 ± 0.5 for benzene, which suggests that additional reactions besides cyano radicals with benzene are involved in the formation of benzonitrile. The formation of these cycles is reasonably well accounted for through a chemical scheme based on neutral-neutral reactions. It is predicted that benzene should be as abundant as cyclopentadiene in TMC-1.
We report the detection of fulvenallene (
c
-C
5
H
4
CCH
2
) in the direction of TMC-1 with the QUIJOTE
1
line survey. Thirty rotational transitions with
K
a
= 0,1,2,3 and
J
= 9−15 were detected. ...The best rotational temperature fitting of the data is 9 K and a derived column density is (2.7 ± 0.3) × 10
12
cm
−2
, which is only a factor of 4.4 below that of its potential precursor cyclopentadiene (
c
-C
5
H
6
), and 1.4–1.9 times higher than that of the ethynyl derivatives of cyclopentadiene. We searched for fulvene (
c
-C
5
H
4
CH
2
), a CH
2
derivative of cyclopentadiene, for which we derive a 3
σ
upper limit to its column density of (3.5 ± 0.5) × 10
12
cm
−2
. Upper limits were also obtained for toluene (C
6
H
5
CH
3
) and styrene (C
6
H
5
C
2
H
3
), the methyl and vinyl derivatives of benzene. Fulvenallene and ethynyl cyclopentadiene are likely formed in the reaction between cyclopentadiene (
c
-C
5
H
6
) and the ehtynyl radical (CCH). However, the bottom-up gas-phase synthesis of cycles in TMC-1 underestimates the abundance of cyclopentadiene by two orders of magnitude, which strengthens the need to study all possible chemical pathways to cyclisation in cold dark cloud environments, such as TMC-1. However, the inclusion of the reaction between C
3
H
3
+
and C
2
H
4
produces a good agreement between model and observed abundances.
Targeted noninvasive control of the nervous system and end-organs may enable safer and more effective treatment of multiple diseases compared to invasive devices or systemic medications. One target ...is the cholinergic anti-inflammatory pathway that consists of the vagus nerve to spleen circuit, which has been stimulated with implantable devices to improve autoimmune conditions such as rheumatoid arthritis. Here we report that daily noninvasive ultrasound (US) stimulation targeting the spleen significantly reduces disease severity in a mouse model of inflammatory arthritis. Improvements are observed only with specific parameters, in which US can provide both protective and therapeutic effects. Single cell RNA sequencing of splenocytes and experiments in genetically-immunodeficient mice reveal the importance of both T and B cell populations in the anti-inflammatory pathway. These findings demonstrate the potential for US stimulation of the spleen to treat inflammatory diseases.
We investigate collective emission from coherently driven ultracold (88)Sr atoms. We perform two sets of experiments using a strong and weak transition that are insensitive and sensitive, ...respectively, to atomic motion at 1 μK. We observe highly directional forward emission with a peak intensity that is enhanced, for the strong transition, by >10(3) compared with that in the transverse direction. This is accompanied by substantial broadening of spectral lines. For the weak transition, the forward enhancement is substantially reduced due to motion. Meanwhile, a density-dependent frequency shift of the weak transition (∼10% of the natural linewidth) is observed. In contrast, this shift is suppressed to <1% of the natural linewidth for the strong transition. Along the transverse direction, we observe strong polarization dependences of the fluorescence intensity and line broadening for both transitions. The measurements are reproduced with a theoretical model treating the atoms as coherent, interacting radiating dipoles.
We present experimental and theoretical results on formation of quantum vortices in a laser beam propagating in a nonlinear medium. Topological constrains richer than the mere conservation of ...vorticity impose an elaborate dynamical behavior to the formation and annihilation of vortex-antivortex pairs. We identify two such mechanisms, both described by the same fold-Hopf bifurcation. One of them is particularly efficient although it is not observed in the context of liquid helium films or stationary systems because it relies on the compressible nature of the fluid of light we consider and on the nonstationarity of its flow.
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