Facile NMR Relaxation Sensor for Monitoring of Biomass Degradation Products during Conversion to Biogas

The chemical and morphological composition of animal biowaste is known to limit the efficiency of methane production by bacterial anaerobic digestion (AD). To better understand these material limitations, we studied degradative changes in cattle manure’s organic complex components chemical and morphological composition during its AD to methane. This was achieved using low field 1H NMR relaxation times domain (TD) spectral mapping combined with T1 (spin-lattice) and T2 (spin-spin) TD of cattle manure biomass (CM) peaks assignment, starting from samples of initial freshly collected CM biomass sample followed by several time points sampling during 21 days cycle of the AD process. A T1-T2 relaxation TD graph giving a stable reproducible pattern of 12 peaks was generated, and assigned to different domains, whose changes during AD could be observed. These 12 peaks were assigned to TDs of crystalline nano-aggregated complexes of different degrees of crystallinity with low porosity and low hydration rate and a morphological group of amorphous domains with increased pore size, density, and higher hydration. In agreement with models of elementary cellulose fibrils, these domains were designated as three layers of cellulose consisting of interior, subsurface, and surface. The most amorphous TD volume showed good correlation with biogas production and could serve as an indicator for digestibility and cellulose conversion to a glucose intermediate during the AD process. This study demonstrated the facile and versatile usage of 2D 1H NMR T1-T2 sensorial technology in studying complex biowaste systems, with the potential for improving CM biomass conversion efficiency into bio-methane

Evaluation of trends in derived snowfall and rainfall across Eurasia and linkages with discharge to the Arctic Ocean

To more fully understand the role of precipitation in observed increases in freshwater discharge to the Arctic Ocean, data from a new archive of bias-adjusted precipitation records for the former USSR (TD9813), along with the CRU and Willmott-Matsuura data sets, were examined for the period 1936–1999. Across the six largest Eurasian river basins, snowfall derived from TD9813 exhibits a strongly significant increase until the late 1950s and a moderately significant decrease thereafter. A strongly significant decline in derived rainfall is also noted. Spatially, snowfall increases are found primarily across north-central Eurasia, an area where the rainfall decreases are most prominent. Although no significant change is determined in Eurasian-basin snowfall over the entire 64 year period, we note that interpolation from early, uneven station networks causes an overestimation of spatial precipitation, and that the local snowfall trends determined from gridded TD9813 data are likely underestimated. Yet, numerous uncertainties in historical Arctic climate data and the sparse, irregular nature of Arctic station networks preclude a confident assessment of precipitation-discharge linkages during the period of reported discharge trends

Favorable outcome of early treatment of new onset child and adolescent migraine-implications for disease modification.

There is evidence that the prevalence of migraine in children and adolescents may be increasing. Current theories of migraine pathophysiology in adults suggest activation of central cortical and brainstem pathways in conjunction with the peripheral trigeminovascular system, which ultimately results in release of neuropeptides, facilitation of central pain pathways, neurogenic inflammation surrounding peripheral vessels, and vasodilatation. Although several risk factors for frequent episodic, chronic, and refractory migraine have been identified, the causes of migraine progression are not known. Migraine pathophysiology has not been fully evaluated in children. In this review, we will first discuss the evidence that early therapeutic interventions in the child or adolescent new onset migraineur, may halt or limit progression and disability. We will then review the evidence suggesting that many adults with chronic or refractory migraine developed their migraine as children or adolescents and may not have been treated adequately with migraine-specific therapy. Finally, we will show that early, appropriate and optimal treatment of migraine during childhood and adolescence may result in disease modification and prevent progression of this disease

Shrinking II -- The Distortion of the Area Distance-Redshift Relation in Inhomogeneous Isotropic Universes

This paper and the others in the series challenge the standard model of the effects of gravitational lensing on observations at large distances. We show that due to the cumulative effect of lensing, areas corresponding to an observed solid angle can be quite different than would be estimated from the corresponding Friedmann-Lema\^{\i}tre model, even when averaged over large angular scales. This paper concentrates on the specific example of spherically symmetric but spatially inhomogeneous dust universes, the Lema\^{\i}tre-Tolman-Bondi models, and shows that radial lensing significantly distorts the area distance-redshift and density-redshift relations in these exact solutions compared with the standard ones for Friedmann-Lema\^{\i}tre models. Thus inhomogeneity may introduce significant errors into distance estimates based on the standard FL relations, even after all-sky averaging. In addition a useful new gauge choice is presented for these models, solving the problem of locating the past null cone exactly.Comment: Minor technical refinement, 16 pages, RevTex, 8 eps figure