The impacts of taxes on firm entry rates along state borders

This paper uses a regression discontinuity approach to estimate the impacts of taxes on firm entry rates between neighboring states. We utilize matched county pairs as an approximate bandwidth around the discontinuity in state policies imposed at their border. This estimation strategy controls for unobserved location specific determinants of firm entry, as well as policy responses to shocks shared across borders. We estimate this impact using a sample of 107 state-border pairs between 1999 and 2009. We add to the literature by using the large array of top marginal tax rates, including property, income, sales, corporate, capital gains, workers compensation, and unemployment insurance tax rates. This controls for joint changes in tax rates that governments may implement to accomplish policy goals. Our results indicate that property, sales, and income taxes have the largest negative effect on firm start up rates

Development of a simulated round of golf

Purpose The aim of this study was to develop a laboratory-based treadmill simulation of the on-course physiological demands of an 18-hole round of golf and to identify the underlying physiological responses. Methods Eight amateur golfers completed a round of golf during which heart rate (HR), steps taken, and global positioning system (GPS) data were assessed. The GPS data were used to create a simulated discontinuous round on a treadmill. Steps taken and HR were recorded during the simulated round. Results During the on-course round, players covered a mean (±SD) of 8,251 ± 450 m, taking 12,766 ± 1,530 steps. The mean exercise intensity during the on-course round was 31.4 ± 9.3% of age-predicted heart rate reserve (%HRR) or 55.6 ± 4.4% of age-predicted maximum HR (%HRmax). There were no significant differences between the simulated round and the on-course round for %HRR (P = .537) or %HR max (P = .561) over the entire round or for each individual hole. Furthermore, there were no significant differences between the two rounds for steps taken. Typical error values for steps taken, HR, %HRmax, and %HRR were 1,083 steps, ±7.6 b·min?1, ±4.5%, and ±8.1%, respectively. Conclusion Overall, the simulated round of golf successfully recreated the demands of an on-course round. This simulated round could be used as a research tool to assess the extent of fatigue during a round of golf or the impact of various interventions on golfers

The Mrs1 Splicing Factor Binds the bI3 Group I Intron at Each of Two Tetraloop-Receptor Motifs

Most large ribozymes require protein cofactors in order to function efficiently. The yeast mitochondrial bI3 group I intron requires two proteins for efficient splicing, Mrs1 and the bI3 maturase. Mrs1 has evolved from DNA junction resolvases to function as an RNA cofactor for at least two group I introns; however, the RNA binding site and the mechanism by which Mrs1 facilitates splicing were unknown. Here we use high-throughput RNA structure analysis to show that Mrs1 binds a ubiquitous RNA tertiary structure motif, the GNRA tetraloop-receptor interaction, at two sites in the bI3 RNA. Mrs1 also interacts at similar tetraloop-receptor elements, as well as other structures, in the self-folding Azoarcus group I intron and in the RNase P enzyme. Thus, Mrs1 recognizes general features found in the tetraloop-receptor motif. Identification of the two Mrs1 binding sites now makes it possible to create a model of the complete six-component bI3 ribonucleoprotein. All protein cofactors bind at the periphery of the RNA such that every long-range RNA tertiary interaction is stabilized by protein binding, involving either Mrs1 or the bI3 maturase. This work emphasizes the strong evolutionary pressure to bolster RNA tertiary structure with RNA-binding interactions as seen in the ribosome, spliceosome, and other large RNA machines

Clustering in mixing flows

We calculate the Lyapunov exponents for particles suspended in a random three-dimensional flow, concentrating on the limit where the viscous damping rate is small compared to the inverse correlation time. In this limit Lyapunov exponents are obtained as a power series in epsilon, a dimensionless measure of the particle inertia. Although the perturbation generates an asymptotic series, we obtain accurate results from a Pade-Borel summation. Our results prove that particles suspended in an incompressible random mixing flow can show pronounced clustering when the Stokes number is large and we characterise two distinct clustering effects which occur in that limit.Comment: 5 pages, 1 figur

SHAPE Analysis of Long-Range Interactions Reveals Extensive and Thermodynamically Preferred Misfolding in a Fragile Group I Intron RNA †

Most functional RNAs require proteins to facilitate formation of their active structures. In the case of the yeast bI3 group I intron, splicing requires binding by two proteins, the intron-encoded bI3 maturase and the nuclear encoded Mrs1. Here, we use selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry coupled with analysis of point mutants to map long-range interactions in this RNA. This analysis reveals two critical features of the free RNA state. First, the catalytic intron is separated from the flanking exons via a stable anchoring helix. This anchoring helix creates an autonomous structural domain for the intron and functions to prevent misfolding with the flanking exons. Second, the thermodynamically most stable structure for the free RNA is not consistent with the catalytically active conformation as phylogenetically conserved elements form stable, non-native structures. These results highlight a fragile bI3 RNA for which binding by protein cofactors functions to promote extensive secondary structure rearrangements that are an obligatory prerequisite for forming the catalytically active tertiary structure

Telomere length predicts for outcome to FCR chemotherapy in CLL

We have previously shown that dividing patients with CLL into those with telomeres inside the fusogenic range (TL-IFR) and outside the fusogenic range (TL-OFR) is powerful prognostic tool. Here, we used a high-throughput version of the assay (HT-STELA) to establish whether telomere length could predict for outcome to fludarabine, cyclophosphamide, rituximab (FCR)-based treatment using samples collected from two concurrent phase II studies, ARCTIC and ADMIRE (n = 260). In univariate analysis, patients with TL-IFR had reduced progression-free survival (PFS) (P < 0.0001; HR = 2.17) and shorter overall survival (OS) (P = 0.0002; HR = 2.44). Bifurcation of the IGHV-mutated and unmutated subsets according to telomere length revealed that patients with TL-IFR in each subset had shorter PFS (HR = 4.35 and HR = 1.48, respectively) and shorter OS (HR = 3.81 and HR = 2.18, respectively). In addition, the OS of the TL-OFR and TL-IFR subsets were not significantly altered by IGHV mutation status (P = 0.61; HR = 1.24 and P = 0.41; HR = 1.47, respectively). In multivariate modeling, telomere length was the dominant co-variable for PFS (P = 0.0002; HR = 1.85) and OS (P = 0.05; HR = 1.61). Taken together, our data suggest that HT-STELA is a powerful predictor of outcome to FCR-based treatment and could be used to inform the design of future risk-adapted clinical trials

Hard Burst Emission from the Soft Gamma Repeater SGR 1900+14

We present evidence for burst emission from SGR 1900+14 with a power-law high energy spectrum extending beyond 500 keV. Unlike previous detections of high energy photons during bursts from SGRs, these emissions are not associated with high-luminosity burst intervals. Not only is the emission hard, but the spectra are better fit by Band's GRB function rather than by the traditional optically-thin thermal bremsstrahlung model. We find that the spectral evolution within these hard events obeys a hardness/intensity anti-correlation. Temporally, these events are distinct from typical SGR burst emissions in that they are longer (~ 1 s) and have relatively smooth profiles. Despite a difference in peak luminosity of > 1E+11 between these bursts from SGR 1900+14 and cosmological GRBs, there are striking temporal and spectral similarities between the two kinds of bursts, aside from spectral evolution. We outline an interpretation of these events in the context of the magnetar model.Comment: 11 pages (text and figures), submitted to ApJ Letters, corrected erroneous hardness ratio

An overview of the extratropical storm tracks in CMIP6 historical simulations

The representation of the winter and summer extratropical storm tracks in both hemispheres is evaluated in detail for the available models in the 6th phase of the Coupled Model Intercomparison Project (CMIP6). The state of the storm tracks from 1979-2014 is compared to that in ERA5 using a Lagrangian objective cyclone tracking algorithm. It is found that the main biases present in the previous generation of models (CMIP5) still persist, albeit to a lesser extent. The equatorward bias around the SH is much reduced and there appears to be some improvement in mean biases with the higher resolution models, such as the zonal tilt of the North Atlantic storm track. Low resolution models have a tendency to under-estimate the frequency of high intensity cyclones with all models simulating a peak intensity that is too low for cyclones in the SH. Explosively developing cyclones are under-estimated across all ocean basins and in both hemispheres. In particular the models struggle to capture the rapid deepening required for these cyclones. For all measures, the CMIP6 models exhibit an overall improvement compared to the previous generation of CMIP5 models. In the NH most improvements can be attributed to increased horizontal resolution, whereas in the SH the impact of resolution is less apparent and any improvements are likely a result of improved model physics

Gravitational waveforms for neutron star binaries from binary black hole simulations

Gravitational waves from binary neutron star (BNS) and black-hole/neutron star (BHNS) inspirals are primary sources for detection by the Advanced Laser Interferometer Gravitational-Wave Observatory. The tidal forces acting on the neutron stars induce changes in the phase evolution of the gravitational waveform, and these changes can be used to constrain the nuclear equation of state. Current methods of generating BNS and BHNS waveforms rely on either computationally challenging full 3D hydrodynamical simulations or approximate analytic solutions. We introduce a new method for computing inspiral waveforms for BNS/BHNS systems by adding the post-Newtonian (PN) tidal effects to full numerical simulations of binary black holes (BBHs), effectively replacing the non-tidal terms in the PN expansion with BBH results. Comparing a waveform generated with this method against a full hydrodynamical simulation of a BNS inspiral yields a phase difference of < 1 radian over ~ 15 orbits. The numerical phase accuracy required of BNS simulations to measure the accuracy of the method we present here is estimated as a function of the tidal deformability parameter ⋋