The origin of green icebergs in Antarctica

A comparison of samples from a translucent green iceberg with a core from the Ronne Ice Shelf revealed an excellent agreement in isotopic composition, crystal structure, and incorporated sediment particles. Marine shelf ice which constitutes the basal portion of some ice shelves is considered to be the source of green icebergs. It most likely results from "ice pump" processes which produce large amounts of ice platelets in the water column beneath ice shelves. These subsequently accumulate and become compacted into bubble-free, desalinated ice. Iceberg and drift-buoy trajectories indicate that green icebergs observed in the Weddell Sea originate from the Amery Ice Shelf rather than from the Ronne Ice Shelf, although the latter ice shelf is also a potential source

The Taxation of Treasury Inflation Protected Securities: Are They Tax-Disadvantaged?

Inflation is back, causing problems for taxpayers looking for safe, inflation-protected investments. This Article engages in an in-depth analysis of an understudied part of the Internal Revenue Code and associated Treasury Regulations section 1.1275-7 the inflation-indexed debt rules, asking whether Treasury Inflation Protected Securities (TIPS) can act as a suitable hedge against inflation for taxable investors. TIPS are often considered tax-disadvantaged instruments, and this Article questions the extent to which that is true. I examine TIPS relative to inflation, nominal Treasuries and I Bonds, and in doing so make three important contributions to tax scholarship. First, I present original empirical analysis on financial data from the 2003-22 period, finding that TIPS are taxed at least as favorably as nominal Treasuries on a buy-and-hold basis. Under certain assumptions, like interest withholding, the section 1.1275-7 regime imposes less onerous tax consequences on TIPS than on nominals. Second, my results confirm that the performance of TIPS relative to nominal Treasuries depends on how unanticipated inflation deviates from expected inflation. Analysis of the 2003-21 period shows that nominals outperformed TIPS on both a pre- and a post-tax basis, while analysis of the 2003-22 period shows that 10-year TIPS issued between 2012 and 2022 generally outperformed nominals precisely because of the rise in unanticipated inflation in 2021 caused by the response to COVID-19. Third, I find that since 2011 all riskless bonds have generally had negative real yields on an after-tax basis. These findings have important implications for current tax policy since they show that taxpayers cannot access positive real riskless returns on an after-tax basis. With the world in a period of rising interest rates and high inflation, this suggests that it may be time to reconsider the canonical emphasis on nominal rather than real taxation

A Tribute From Robin Morgan: Kate Millett Memorial Service

A Tribute From Robin Morgan includes the text of her tribute and a video. The tribute is read by Kathleen Turner

Stellar populations in a standard ISOGAL field in the Galactic disk

We aim to identify the stellar populations (mostly red giants and young stars) detected in the ISOGAL survey at 7 and 15micron towards a field (LN45) in the direction l=-45, b=0.0. The sources detected in the survey of the Galactic plane by the Infrared Space Observatory are characterized based on colour-colour and colour-magnitude diagrams. We combine the ISOGAL catalog with the data from surveys such as 2MASS and GLIMPSE. Interstellar extinction and distance are estimated using the red clump stars detected by 2MASS in combination with the isochrones for the AGB/RGB branch. Absolute magnitudes are thus derived and the stellar populations are identified based on their absolute magnitudes and their infrared excess. A standard approach to the analysis of ISOGAL disk observations has been established. We identify several hundred RGB/AGB stars and 22 candidate young stellar objects in the direction of this field in an area of 0.16 deg^2. An over-density of stellar sources is found at distances corresponding to the distance of the Scutum-Crux spiral arm. In addition, we determine mass-loss rates of AGB-stars using dust radiative transfer models from the literature.Comment: 48pages, 38 figures, accepted for publication in A &

Are plant breeders willing to change food systems?

Food systems is the term for the all-encompassing entity which includes the individuals involved in growing, transforming, and consuming food. From this perspective of course food is the essential core of the whole system. No food, no system. Every food item derives, directly or indirectly, from a plant. Most likely a domesticated plant, an organism that has been selected to fit and fulfill the desires of a particular group of people, a work of careful selection carried out initially by farmers and more recently by plant breeders. Wheat well exemplifies this relationship. A staple crop that has accompanied a significant amount of the human population for thousands of years, changing according to new latitudes, pathogens and tastes, today however wheat is shaped not so much by “us” but by the organized forces of the market. Refined flour is the focus of the American wheat industry, tasking breeders to develop varieties yielding high amounts of white refined flour satisfying the consumer’s demand for white bread. Breeders have the agency to shape crops, and consequently to enable cropping and food systems. Wheat has been bred to produce refined flour for over 150 years. A fact likely contributing to the current deficiency in dietary fiber experienced by the vast majority of the American population. Wheat breeders instead, could be working on developing varieties for whole grain use, overcoming technological and organoleptic concerns and limitations to its adoption. From an agronomic perspective, wheat also could be bred to overcome some of the negative externalities associated with its production, for example soil erosion. Hybridizing wheat with perennial wild relatives produces a perennial grain crop, combining potential soil health benefits and grain production. Breeders have contributed to change nutritional and agricultural landscapes in the past, will they now take the initiative to address present societal and environmental issues

Complement system biomarkers in first episode psychosis

Several lines of evidence implicate immunological/inflammatory factors in development of schizophrenia. Complement is a key driver of inflammation, and complement dysregulation causes pathology in many diseases. Here we exploredwhether complement dysregulation occurred in first episode psychosis (FEP) andwhether this provides a source of biomarkers. Eleven complement analytes (C1q, C3, C4, C5, factor B [FB], terminal complement complex [TCC], factor H [FH], FH-related proteins [FHR125], Properdin, C1 inhibitor [C1inh], soluble complement receptor 1 [CR1]) plus C-reactive protein (CRP) were measured in serum from 136 first episode psychosis (FEP) cases and 42 mentally healthy controls using established in-house or commercial ELISA. The relationship between caseness and variables (analytes measured, sex, age, ethnicity, tobacco/cannabis smoking) was tested by multivariate logistic regression. Whenmeasured individually, only TCC was significantly different between FEP and controls (p=0.01). Stepwise selection demonstrated interdependence between some variables and revealed other variables that significantly and independently contributed to distinguishing cases and controls. The finalmodel included demographics (sex, ethnicity, age, tobacco smoking) and a subset of analytes (C3, C4, C5, TCC, C1inh, FHR125, CR1). A receiver operating curve analysis combining these variables yielded an area under the curve of 0.79 for differentiating FEP from controls. This model was confirmed by multiple replications using randomly selected sample subsets. The data suggest that complement dysregulation occurs in FEP, supporting an underlying immune/inflammatory component to the disorder. Classification of FEP cases according to biological variables rather than symptoms would help stratify cases to identify those that might most benefit from therapeuticmodification of the inflammatory response

Prevalence and risk factors for myopia and other refractive errors in an adult population in southern India.

PURPOSE: To investigate prevalence and risk factors for myopia, hyperopia and astigmatism in southern India. METHODS: Randomly sampled villages were enumerated to identify people aged ≥40 years. Participants were interviewed for socioeconomic and lifestyle factors and attended a hospital-based ophthalmic examination including visual acuity measurement and objective and subjective measurement of refractive status. Myopia was defined as spherical equivalent (SE) worse than -0.75 dioptres (D), hyperopia as SE ≥+1D and astigmatism as cylinder <-0.5. RESULTS: The age-standardised prevalences of myopia, hyperopia and astigmatism were 35.6% (95% CI: 34.7-36.6), 17.0% (95% CI: 16.3-17.8) and 32.6 (29.3-36.1), respectively. Of those with myopia (n = 1490), 70% had advanced cataract. Of these, 79% had presenting visual acuity (VA) less than 6/18 and after best correction, 44% of these improved to 6/12 or better and 27% remained with VA less than 6/18. In multivariable analyses (excluding patients with advanced cataract), increasing nuclear opacity score, current tobacco use, and increasing height were associated with higher odds of myopia. Higher levels of education were associated with increased odds of myopia in younger people and decreased odds in older people. Increasing time outdoors was associated with myopia only in older people. Increasing age and female gender were associated with hyperopia, and nuclear opacity score, increasing time outdoors, rural residence and current tobacco use with lower odds of hyperopia. After controlling for myopia, factors associated with higher odds of astigmatism were age, rural residence, and increasing nuclear opacity score and increasing education with lower odds. CONCLUSIONS: In contrast to high-income settings and in agreement with studies from low-income settings, we found a rise in myopia with increasing age reflecting the high prevalence of advanced cataract

Emerging roles of chicken and viral microRNAs in avian disease

<p> Abstract</p> <p>Background</p> <p>MicroRNAs are short RNAs (~22 nt) expressed by plants, animals and viruses that regulate gene expression post-transcriptionally, and their importance is highlighted by distinct patterns of expression in many physiological processes, including development, hematopoeisis, stress resistance, and disease. Our group has characterized the microRNAs encoded by the avian herpesviruses; namely, oncogenic Marek’s disease (MD) virus (MDV1), non-oncogenic MDV (MDV2) herpesvirus of turkeys (HVT), and infectious laryngotracheitis virus (ILTV).</p> <p>Methods</p> <p>MicroRNAs encoded by the avian herpesviruses were identified using next generation sequencing technologies (454, Illumina).</p> <p>Results</p> <p>The microRNAs of each the avian herpesviruses have unique sequences, but the genomic locations are similar, in that the microRNAs tend to be clustered in the rapidly evolving repeat regions of the viral genomes. For a given viral species the microRNA sequence is highly conserved in different strains with the exception of a virulence-associated polymorphism in the putative promoter of the MDV1 microRNAs upstream of the <it>meq</it> oncogene. These microRNAs are relatively highly expressed in tumors produced by very virulent MDV1 isolates compared to tumors produced by less virulent strains. MDV1 and HVT encode homologs of the host microRNA, miR-221, which targets a gene important in cell cycle regulation. MDV1 encodes a microRNA (mdv1-miR-M4) that shares a seed sequence with miR-155, a microRNA important in immune function. Mdv-miR-M4 is highly expressed in MDV induced tumors, while miR-155 is present at very low levels.</p> <p>Conclusions</p> <p>MicroRNAs are highly conserved among different field strains of MDV1, and they are expressed in lytic and latent infections and in MDV1-derived tumors. This suggests that these small molecules are very important to the virus, and roles in immune evasion, anti-apoptosis, or proliferation are likely.</p