Models of planetary rings

The Voyager occultations provide several uniform and high quality data sets for Saturn, Uranus, and Neptune. These data are intercompared, and theoretical models for the particle sizes and the particle transport are developed. The major topics covered include: ring size distribution, torques and resonances, and satellite wakes

The prevalence of platelet activating factor acetylhydrolase single nucleotide polymorphisms in relationship to necrotizing enterocolitis in Northwest Louisiana infants

PURPOSE: Studies documented that platelet activating factor (PAF) and the enzyme platelet activating factor acetylhydrolase (PAFAH) play a very important role in the pathogenesis of neonatal necrotizing enterocolitis (NEC). In this retrospective, case-controlled pilot study, the authors investigated the prevalence of single nucleotide polymorphisms (Ile198Thr and Ala379Val) of the PAFAH gene. SUBJECTS AND METHODS: We screened 570 blood samples from both Caucasian and African-American preterm infants in the Northwest Louisiana population for the above mentioned PAFAH gene polymorphisms. Out of 570 infants, 36 had stage I or II NEC based on diagnostic coding, the International Classification of Diseases, 9th revision, Clinical Modification, 2009 (ICD-9-CM). The remaining infants without an ICD-9-CM diagnosis of NEC were recruited as control population. The DNA was isolated and restriction fragment length polymorphism microplate polymerase chain reaction assay was performed. RESULTS: Variants of the PAFAH gene polymorphism (Ile198Thr and Ala379Val) frequencies were not significantly different between the infants with NEC and the control group (P value of 0.26 by either multiple logistic regression analysis or the Cochran-Mantel-Haenszel test). CONCLUSIONS: This is the first study of its kind in exploring the relationship between NEC and single nucleotide polymorphisms in the coding genes of the enzyme PAFAH. Our preliminary data demonstrated that adjusted for the effect of race, PAFAH polymorphisms (Ile198Thr and Ala379Val) have no significant effect on NEC

Assessing the Time Variability of Jupiter's Tropospheric Properties from 1996 to 2011

We acquired and analyzed mid-infrared images of Jupiter's disk at selected wavelengths from NASA's Infrared Telescope Facility (IRTF) from 1996 to 2011, including a period of large-scale changes of cloud color and albedo. We derived the 100-300 mbar temperature structure, together with tracers of vertical motion: the thickness of a 600- mbar cloud layer, the 300-mbar abundance of the condensable gas NH3, and the 400- mbar para- vs. ortho-H2 ratio. The biggest visual change was detected in the normally dark South Equatorial Belt (SEB) that 'faded' to a light color in 2010, during which both cloud thickness and NH3 abundance rose; both returned to their pre-fade levels in 2011, as the SEB regained its normal dark color. The cloud thickness in Jupiter's North Temperate Belt (NTB) increased in 2002, coincident with its visible brightening, and its NH3 abundance spiked in 2002-2003. Jupiter's Equatorial Zone (EZ), a region marked by more subtle but widespread color and albedo change, showed high cloud thickness variability between 2007 and 2009. In Jupiter's North Equatorial Belt (NEB), the cloud thickened in 2005, then slowly decreased to a minimum value in 2010-2011. No temperature variations were associated with any of these changes, but we discovered temperature oscillations of approx.2-4 K in all regions, with 4- or 8-year periods and phasing that was dissimilar in the different regions. There was also no detectable change in the para- vs. ortho-H2 ratio over time, leading to the possibility that it is driven from much deeper atmospheric levels and may be time-invariant. Our future work will continue to survey the variability of these properties through the Juno mission, which arrives at Jupiter in 2016, and to connect these observations with those made using raster-scanned images from 1980 to 1993 (Orton et al. 1996 Science 265, 625)

S100A6 Amyloid Fibril Formation Is Calcium-modulated and Enhances Superoxide Dismutase-1 (SOD1) Aggregation

S100A6 is a small EF-hand calcium- and zinc-binding protein involved in the regulation of cell proliferation and cytoskeletal dynamics. It is overexpressed in neurodegenerative disorders and a proposed marker for Amyotrophic Lateral Sclerosis (ALS). Following recent reports of amyloid formation by S100 proteins, we investigated the aggregation properties of S100A6. Computational analysis using aggregation predictors Waltz and Zyggregator revealed increased propensity within S100A6 helices HI and HIV. Subsequent analysis of Thioflavin-T binding kinetics under acidic conditions elicited a very fast process with no lag phase and extensive formation of aggregates and stacked fibrils as observed by electron microscopy. Ca2+ exerted an inhibitory effect on the aggregation kinetics, which could be reverted upon chelation. An FT-IR investigation of the early conformational changes occurring under these conditions showed that Ca2+ promotes anti-parallel β-sheet conformations that repress fibrillation. At pH 7, Ca2+ rendered the fibril formation kinetics slower: time-resolved imaging showed that fibril formation is highly suppressed, with aggregates forming instead. In the absence of metals an extensive network of fibrils is formed. S100A6 oligomers, but not fibrils, were found to be cytotoxic, decreasing cell viability by up to 40%. This effect was not observed when the aggregates were formed in the presence of Ca2+. Interestingly, native S1006 seeds SOD1 aggregation, shortening its nucleation process. This suggests a cross-talk between these two proteins involved in ALS. Overall, these results put forward novel roles for S100 proteins, whose metal-modulated aggregation propensity may be a key aspect in their physiology and function

Communication Strategy, Central Banking and Credibility Bonus - A Study dealing with Impossible Trinity in Indian Context

The Communication strategy for central banks is traditionally interlinked with one of theirimportant mandates – conduct of monetary policy. Credibility to central bank actions inthe process is achieved by keeping the market expectations more closely synchronisedwith its own, through the art of communication. However, the management of“Impossible Trinity” in the context of Emerging Market Economies expands the scope ofcommunication strategy of central banks to horizons other than the conduct of monetarypolicy. The paper, therefore, examines a pertinent research question - How did themanagement of “Impossible Trinity” impact the communication strategiesadopted by Reserve Bank of India (RBI) and the credibility of its actions amongstthe market participants? The paper reviews the RBI’s efforts to demystify its policystances since past few years under the policy options thrown up by the impossible trinityand its perceived impact on market participants. The Case study, drawn from existingacademic literature, variety of RBI publications and speeches of RBI senior officials,review of media reports, can constitute an important contribution to the emergingresearch area in the South Asian central banking

Anti-tau antibody reduces insoluble tau and decreases brain atrophy

OBJECTIVE: We previously found a strong reduction in tau pathology and insoluble tau in P301S tau transgenic mice following intracerebroventricular infusion of the anti-tau antibody HJ8.5. We sought to determine the effects of HJ8.5 in the same model following peripheral administration. METHODS: The primary objective was to determine if HJ8.5 administered at a dose of 50 mg kg(−1) week(−1) by intraperitoneal (IP) injection to 6-month-old P301S mice for 3 months would influence phospho-tau (p-tau) accumulation, tau insolubility, and neurodegeneration. RESULTS: Treatment with HJ8.5 at 50 mg/kg showed a very strong decrease in detergent-insoluble tau. Importantly, HJ8.5 significantly reduced the loss of cortical and hippocampal tissue volumes compared to control treated mice. HJ8.5 treatment reduced hippocampal CA1 cellular layer staining with the p-tau antibody AT8 and thio-S-positive tau aggregates in piriform cortex and amygdala. Moreover, mice treated with HJ8.5 at 50 mg/kg showed a decrease in motor/sensorimotor deficits compared to vehicle-treated mice. Some effects of HJ8.5, including reduction in brain atrophy, and p-tau immunostaining were also seen with a dose of 10 mg kg(−1) week(−1). In BV2-microglial cells, we observed significantly higher uptake of P301S tau aggregates in the presence of HJ8.5. HJ8.5 treatment also resulted in a large dose-dependent increase of tau in the plasma. INTERPRETATION: Our results indicate that systemically administered anti-tau antibody HJ8.5 significantly decreases insoluble tau, decreases brain atrophy, and improves motor/sensorimotor function in a mouse model of tauopathy. These data further support the idea that anti-tau antibodies should be further assessed as a potential treatment for tauopathies