Store cotton before ginning?

Cover title.Includes bibliographical references

Assembling, storing and ginning cotton in the Mississippi Delta

The Agricultural Experiment Stations of Arizona, Arkansas, Georgia, Louisiana, Mississippi, Missouri, New Mexico, Tennessee, and Texas, cooperating.Includes bibliographical references

Letter to Sonora Dodd from Leon V. Metcalf, May 6, 1945

Letter to Sonora Dodd from Leon V. Metcalf, with envelope.https://digitalcommons.whitworth.edu/fathers-day-correspondence/1136/thumbnail.jp

Initializing a Quantum Register from Mott Insulator States in Optical Lattices

We propose and quantitatively develop two schemes to quickly and accurately generate a stable initial configuration of neutral atoms in optical microtraps by extraction from the Mott insulator state in optical lattices. We show that thousands of atoms may be extracted and stored in the ground states of optical microtrap arrays with one atom per trap in one operational process demonstrating massive scalability. The failure probability during extraction in the first scheme can be made sufficiently small (10^{-4}) to initialize a large scale quantum register with high fidelity. A complementary faster scheme with more extracted atoms but lower fidelity is also developed.Comment: 5 pages, 3 figure

Mechanical stripping vs. mechanical picking of cotton

Cover title

Early diffusion evidence of retrograde transsynaptic degeneration in the human visual system

We investigated whether diffusion tensor imaging (DTI) indices of white matter integrity would offer early markers of retrograde transsynaptic degeneration (RTD) in the visual system after stroke Objective: We investigated whether diffusion tensor imaging (DTI) indices of white matter integrity would offer early markers of retrograde transsynaptic degeneration (RTD) in the visual system after stroke. Methods: We performed a prospective longitudinal analysis of the sensitivity of DTI markers of optic tract health in 12 patients with postsynaptic visual pathway stroke, 12 stroke controls, and 28 healthy controls. We examined group differences in (1) optic tract fractional anisotropy (FA-asymmetry), (2) perimetric measures of visual impairment, and (3) the relationship between FA-asymmetry and perimetric assessment. Results: FA-asymmetry was higher in patients with visual pathway lesions than in control groups. These differences were evident 3 months from the time of injury and did not change significantly at 12 months. Perimetric measures showed evidence of impairment in participants with visual pathway stroke but not in control groups. A significant association was observed between FA-asymmetry and perimetric measures at 3 months, which persisted at 12 months. Conclusions: DTI markers of RTD are apparent 3 months from the time of injury. This represents the earliest noninvasive evidence of RTD in any species. Furthermore, these measures associate with measures of visual impairment. DTI measures offer a reproducible, noninvasive, and sensitive method of investigating RTD and its role in visual impairment

Doppler cooling with coherent trains of laser pulses and tunable "velocity comb"

We explore the possibility of decelerating and Doppler cooling of an ensemble of two-level atoms by a coherent train of short, non-overlapping laser pulses. We develop a simple analytical model for dynamics of a two-level system driven by the resulting frequency comb field. We find that the effective scattering force mimics the underlying frequency comb structure. The force pattern depends strongly on the ratio of the atomic lifetime to the repetition time and pulse area. For example, in the limit of short lifetimes, the frequency peaks of the optical force wash out. We show that laser cooling with pulse trains results in a "velocity comb", a series of narrow peaks in the velocity space

Continuous Loading of a Conservative Trap from an Atomic Beam

We demonstrate the fast accumulation of Cr atoms in a conservative potential from a magnetically guided atomic beam. Without laser cooling on a cycling transition, a single dissipative step realized by optical pumping allows to load atoms at a rate of 2*10^7 1/s in the trap. Within less than 100 ms we reach the collisionally dense regime, from which we directly produce a Bose-Einstein condensate with subsequent evaporative cooling. This constitutes a new approach to degeneracy where, provided a slow beam of particles can be produced by some means, Bose-Einstein condensation can be reached for species without a cycling transition.Comment: 4 pages, 4 figure

Probing nn-Spin Correlations in Optical Lattices

We propose a technique to measure multi-spin correlation functions of arbitrary range as determined by the ground states of spinful cold atoms in optical lattices. We show that an observation of the atomic version of the Stokes parameters, using focused lasers and microwave pulsing, can be related to $n$-spin correlators. We discuss the possibility of detecting not only ground state static spin correlations, but also time-dependent spin wave dynamics as a demonstrative example using our proposed technique.Comment: 7 pages, 4 figure

Constraining Warm Dark Matter using QSO gravitational lensing

Warm Dark Matter (WDM) has been invoked to resolve apparent conflicts of Cold Dark Matter (CDM) models with observations on subgalactic scales. In this work we provide a new and independent lower limit for the WDM particle mass (e.g. sterile neutrino) through the analysis of image fluxes in gravitationally lensed QSOs. Starting from a theoretical unperturbed cusp configuration we analyze the effects of intergalactic haloes in modifying the fluxes of QSO multiple images, giving rise to the so-called anomalous flux ratio. We found that the global effect of such haloes strongly depends on their mass/abundance ratio and it is maximized for haloes in the mass range 10^6-10^8 \Msun. This result opens up a new possibility to constrain CDM predictions on small scales and test different warm candidates, since free streaming of warm dark matter particles can considerably dampen the matter power spectrum in this mass range. As a consequence, while a ($\Lambda$)CDM model is able to produce flux anomalies at a level similar to those observed, a WDM model, with an insufficiently massive particle, fails to reproduce the observational evidences. Our analysis suggests a lower limit of a few keV ($m_{\nu} \sim 10$) for the mass of warm dark matter candidates in the form of a sterile neutrino. This result makes sterile neutrino Warm Dark Matter less attractive as an alternative to Cold Dark Matter, in good agreement with previous findings from Lyman-$\alpha$ forest and Cosmic Microwave Background analysis.Comment: One equation added, typo in eq: 5 corrected, minor changes to match the accepted version by MNRA