The 22-Year Hale Cycle in Cosmic Ray Flux – Evidence for Direct Heliospheric Modulation

Abstract The ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar-cycle variation in cosmic rays is highly correlated with the strength of the heliospheric magnetic field. Differences in GCR flux during alternate solar cycles yield a 22-year cycle, known as the Hale Cycle, which is thought to be due to different particle drift patterns when the northern solar pole has predominantly positive (denoted as qA>0 cycle) or negative (qA0 cycles than for qA0 and more sharply peaked for qA0 solar cycles, when the difference in GCR flux is most apparent. This suggests that particle drifts may not be the sole mechanism responsible for the Hale Cycle in GCR flux at Earth. However, we also demonstrate that these polarity-dependent heliospheric differences are evident during the space-age but are much less clear in earlier data: using geomagnetic reconstructions, we show that for the period of 1905 – 1965, alternate polarities do not give as significant a difference during the declining phase of the solar cycle. Thus we suggest that the 22-year cycle in cosmic-ray flux is at least partly the result of direct modulation by the heliospheric magnetic field and that this effect may be primarily limited to the grand solar maximum of the space-age

Groups and semigroups with a one-counter word problem

We prove that a finitely generated semigroup whose word problem is a one-counter language has a linear growth function. This provides us with a very strong restriction on the structure of such a semigroup, which, in particular, yields an elementary proof of a result of Herbst, that a group with a one-counter word problem is virtually cyclic. We prove also that the word problem of a group is an intersection of finitely many one-counter languages if and only if the group is virtually abelian

Decorin-evoked paternally expressed gene 3 (PEG3) is an upstream regulator of the transcription factor EB (TFEB) in endothelial cell autophagy.

Macroautophagy is a fundamental and evolutionarily conserved catabolic process that eradicates damaged and aging macromolecules and organelles in eukaryotic cells. Decorin, an archetypical small leucine-rich proteoglycan, initiates a protracted autophagic program downstream of VEGF receptor 2 (VEGFR2) signaling that requires paternally expressed gene 3 (PEG3). We have discovered that PEG3 is an upstream transcriptional regulator of transcription factor EB (TFEB), a master transcription factor of lysosomal biogenesis, for decorin-evoked endothelial cell autophagy. We found a functional requirement of PEG3 for TFEB transcriptional induction and nuclear translocation in human umbilical vein endothelial and PAER2 cells. Mechanistically, inhibiting VEGFR2 or AMP-activated protein kinase (AMPK), a major decorin-activated energy sensor kinase, prevented decorin-evoked TFEB induction and nuclear localization. In conclusion, our findings indicate a non-canonical (nutrient- and energy-independent) mechanism underlying the pro-autophagic bioactivity of decorin via PEG3 and TFEB

An Investigation of Techniques for the Separation of Hydrogen and Deuterium: Part I: Zone Refining of Mixtures of Ordinary and Heavy Water; Part II: The Reaction of Iron with Mixtures of Ordinary and Heavy Water; Part III: Gas Chromatography with Hydrogen and Deuterium Samples

The separation factor for a single fractional crystallization in the H2O-D2O system is much too small, and the required freezing rate is too slow for a batch process to give a useful separation of the isotopic forms of water. The purpose of this work was to continue some preliminary experiments on zone refining in the H2O-D2O system and to attempt to determine whether or not the technique would be useful for the separation of heavy water from ordinary water

Franklin D. Roosevelt and Abraham Lincoln: Competing Perspectives on Two Great Presidencies

Threatened with destruction Crises and the rise of great American statesmen Democratic governance is difficult under any circumstances but none more than during wartime. President George W. Bush is currently confronting this reality. For solace he could do worse than turn to the ...

Linear and nonlinear optical properties of metal-dielectric multilayer structures

The object of the present research is to design and fabricate metal-dielectric thin film multilayer structures that make use of the nonlinear optical (NLO) response of Ag for efficient nonlinear absorption for sensor protection. These structures employ structural resonances to overcome the challenges of reflection and absorption that limit access to this large NLO response. The research consists of three parts: first, we present a comprehensive analysis of the contributions to the nonlinear optical response of Ag. Second, we present a systematic investigation of the linear optical properties of Metal-Dielectric Photonic Band-Gap (MDPBG) structures, including optimization of the structure for a particular transmittance spectrum. Third, we study the linear and nonlinear optical properties of Induced Transmission Filters (ITFs). Each of these parts includes experimental results backed by modeling and simulation.Ph.D.Committee Chair: Bernard Kippelen; Committee Member: David Citrin; Committee Member: Farrokh Ayazi; Committee Member: Gee-Kung Chang; Committee Member: Ken Sandhag

Manufactured History?: Study Exposes Conflict Of Myth And Fiction Surrounding Lee

Manufactured history? Study exposes conflict of myth and fiction surrounding Lee For decades no Civil War figure, not even Abraham Lincoln, has surpassed the reputation of Robert E. Lee. Lee has been portrayed as outshining all others on both sides of the conflict not only in sol...