A new code for Fourier-Legendre analysis of large datasets: first results and a comparison with ring-diagram analysis

Fourier-Legendre decomposition (FLD) of solar Doppler imaging data is a promising method to estimate the sub-surface solar meridional flow. FLD is sensible to low-degree oscillation modes and thus has the potential to probe the deep meridional flow. We present a newly developed code to be used for large scale FLD analysis of helioseismic data as provided by the Global Oscillation Network Group (GONG), the Michelson Doppler Imager (MDI) instrument, and the upcoming Helioseismic and Magnetic Imager (HMI) instrument. First results obtained with the new code are qualitatively comparable to those obtained from ring-diagram analyis of the same time series.Comment: 4 pages, 2 figures, 4th HELAS International Conference "Seismological Challenges for Stellar Structure", 1-5 February 2010, Arrecife, Lanzarote (Canary Islands

The Critical Exponent is Computable for Automatic Sequences

The critical exponent of an infinite word is defined to be the supremum of the exponent of each of its factors. For k-automatic sequences, we show that this critical exponent is always either a rational number or infinite, and its value is computable. Our results also apply to variants of the critical exponent, such as the initial critical exponent of Berthe, Holton, and Zamboni and the Diophantine exponent of Adamczewski and Bugeaud. Our work generalizes or recovers previous results of Krieger and others, and is applicable to other situations; e.g., the computation of the optimal recurrence constant for a linearly recurrent k-automatic sequence.Comment: In Proceedings WORDS 2011, arXiv:1108.341

THE IMPACT OF COGNITIVE FUNCTION ON PATIENT LANGUAGE AND QUALITY OF LIFE OUTCOMES FOR STROKE SURVIVORS WITH APHASIA WHO PARTICIPATE IN AN INTENSIVE COMPREHENSIVE APHASIA PROGRAM (ICAP)

Background: Aphasia is an acquired language disorder that impairs communication, across all modalities of language (i.e., reading, writing, speaking, and comprehension). Aphasia most commonly results from damage to the left hemisphere of the brain (e.g., stroke, traumatic brain injury). Cognitive function including attention, memory, and executive functioning may negatively impact patient outcomes during post-acute rehabilitation of aphasia. Intensive Comprehensive Aphasia Programs (ICAPs) provide intensive, evidence-based and holistic treatment for a cohort of stroke survivors. The impact of these cognitive functions on language outcomes following participation in an ICAP has not been explored. Aims: To investigate the impact of extralinguistic cognition and the implementation of a novel cognitive education intervention on language outcomes following for stroke survivors with aphasia who participate in an ICAP. Methods & Procedures: Eight adult stroke survivors with chronic aphasia participated in a 4-week ICAP implemented by graduate students during the Summer of 2022. Participants in the experimental group received cognitive education about attention, memory, executive functioning domains, external cognitive strategies, and internal cognitive strategies. Participants were matched by age and gender into a control or experimental group. Cognitive function, linguistic function, communicative participation, and quality of life was assessed before and after the ICAP. Outcomes & Results: Paired sample t-tests were used to compare pre- and post-ICAP performance on language measures within and across groups. Pearson’s r correlation coefficients were used to evaluate the relationship between pre-ICAP extralinguistic cognition and language-based outcomes. Statistically significant change was observed in the experimental group pre- to post- ICAP language outcomes and between the experimental group and the experimental group for language change scores. Low and moderate correlation between the pre-ICAP extralinguistic cognitive abilities and language change scores was observed. Conclusions: This pilot study suggests that providing cognitive education during an ICAP may positively impact language outcomes for participants with post-stroke aphasia

Experimental evidence for excess entropy discontinuities in glass-forming solutions

Glass transition temperatures T_g are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO_3)_2), malonic acid, raffinose, and ammonium bisulfate (NH_4HSO_4) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T_g of multi-component systems can be predicted using mixing rules. However, the experimentally observed T_g in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T_g. The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account

Electron donor contributions to denitrification in the Elk Valley Aquifer, North Dakota

Six denitrification tracer tests were performed over eight and a half years in in situ mesocosms (ISMs) in the Elk Valley Aquifer (EVA) in east-central North Dakota. Groundwater samples were analyzed to determine how much nitrate was lost beyond that explained by dilution of the bromide tracer. Additional losses were attributed to denitrification. The denitrification rates varied from 0.10 to 0.23 mg N/L/day for the six tests. In general, the major electron donors for denitrification are organic carbon (OC), pyrite (FeS2), and ferrous iron silicate minerals. In the EVA tracer tests, increases in sulfate indicated that the oxidation of pyrite explained a significant of the denitrification. The contributions of the three electron donors varied between tests and from test to test with pyrite, ferrous iron from silicate minerals, and OC apparently contributing 38-84%, 1-3%, and 14-59% to denitrification, respectively

Renormalization and blow up for charge one equivariant critical wave maps

We prove the existence of equivariant finite time blow up solutions for the wave map problem from 2+1 dimensions into the 2-sphere. These solutions are the sum of a dynamically rescaled ground-state harmonic map plus a radiation term. The local energy of the latter tends to zero as time approaches blow up time. This is accomplished by first "renormalizing" the rescaled ground state harmonic map profile by solving an elliptic equation, followed by a perturbative analysis