Are South African women willing and able to apply the new Food-Based Dietary Guidelines? Lessons for nutrition educators

Background Consumer testing was a prime consideration in developing specific South African food-based dietary guidelines (FBDGs) which were nationally adopted in 2003. Objectives This study aimed to determine the consumer's ability to apply the FBDGs appropriately, in terms of identifying foods/drinks according to the FBDG food categories; perceived importance of and barriers to applying each FBDG; and planning a typical day's meals to reflect the FBDGs. Design A cross-sectional study of 333 women from different cultural and socio-economic backgrounds. Setting: KwaZulu-Natal, South Africa. Methods Data collection comprised focus-group discussions (n = 103) and structured individual interviews (n = 230). Results The identification of foods/drinks according to the FBDG food categories reflected a high level of comprehension by participants of these food categories. Participants from all study samples endorsed the importance of applying the FBDGs, predominantly for health reasons. Participants cited barriers to the application of the FBDGs as affordability, availability, household taste preferences, routine food-purchasing habits, time constraints, traditional/ habitual food-preparation methods, and persistent attitudes. Only three FBDGs were mentioned as difficult to apply, namely, “fruits/ vegetables”, “foods from animals” and “legumes”. Meal plans did reflect the FBDGs, illustrating the flexibility of their use across cultural and socio-economic differences. Conclusions Consumer testing of the FBDGs was mainly positive. The study has highlighted areas of confusion regarding certain concepts, terminology and misconceptions, and has identified barriers to application. These concerns can be addressed through the reformulation and retesting of certain dietary guidelines, and the provision of explanatory consumer information and health-worker training materials. SAJCN Vol. 21 (2) 2008: pp. 17-2

Polariton Condensation and Lasing

The similarities and differences between polariton condensation in microcavities and standard lasing in a semiconductor cavity structure are reviewed. The recent experiments on "photon condensation" are also reviewed.Comment: 23 pages, 6 figures; Based on the book chapter in Exciton Polaritons in Microcavities, (Springer Series in Solid State Sciences vol. 172), V. Timofeev and D. Sanvitto, eds., (Springer, 2012

The centrosome and spindle as a ribonucleoprotein complex

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Chromosome Research 19 (2011): 367-376, doi:10.1007/s10577-011-9186-7.The presence of nucleic acids in centrosomes and the spindle have been proposed, observed, and reported since the 1950s. Why did the subject remain, perhaps even until today, such a controversial issue? The explanation is manifold, and includes legitimate concern over contamination from other cellular compartments in biochemical preparations. With a typically high background of cytoplasmic ribosomes, even microscopic images of stained intact cells could be difficult to interpret. Also, evidence for RNA and DNA in centrosomes accumulated for approximately 40 years but was interspersed with contradictory studies, primarily regarding the presence of DNA (reviewed in Johnson and Rosenbaum, 1991; Marshall and Rosenbaum, 2000). Perhaps less tangible but still a likely cause for lingering controversy is that the presence of nucleic acids in the spindle or centrosomes will require us to look differently at these structures from a functional, and more to the point, evolutionary standpoint.This work was supported by grants from the NIH (GM088503) and NSF (MCB0843092) to MCA

Origins, diversity and naturalization of Eucalyptus globulus (Myrtaceae) in California

Eucalyptus globulus is native to southeastern Australia, including the island of Tasmania, but is one of the most widely grown hardwood forestry species in the world and is naturalized on several continents. We studied its naturalization in California, where the species has been planted for over 150 years. We sampled 70 E. globulus trees from 53 locations spanning the entire range of the species in California to quantify the genetic variation present and test whether particular genotypes or native origin affect variation in naturalization among locations. Diversity and native affinities were determined based on six nuclear microsatellite markers and sequences from a highly variable chloroplast DNA region (JLA+). The likely native origin was determined by DNA-based comparison with a range-wide native stand collection. Most of California’s E. globulus originated from eastern Tasmania. Genetic diversity in California is greatly reduced compared with that of the native Australian population, with a single chloroplast haplotype occurring in 66% of the Californian samples. Throughout California, the degree of E. globulus naturalization varies widely but was not associated with genotype or native origin of the trees, arguing that factors such as local climate and disturbance are more important than pre-introduction evolutionary history

The Escherichia coli transcriptome mostly consists of independently regulated modules

Underlying cellular responses is a transcriptional regulatory network (TRN) that modulates gene expression. A useful description of the TRN would decompose the transcriptome into targeted effects of individual transcriptional regulators. Here, we apply unsupervised machine learning to a diverse compendium of over 250 high-quality Escherichia coli RNA-seq datasets to identify 92 statistically independent signals that modulate the expression of specific gene sets. We show that 61 of these transcriptomic signals represent the effects of currently characterized transcriptional regulators. Condition-specific activation of signals is validated by exposure of E. coli to new environmental conditions. The resulting decomposition of the transcriptome provides: a mechanistic, systems-level, network-based explanation of responses to environmental and genetic perturbations; a guide to gene and regulator function discovery; and a basis for characterizing transcriptomic differences in multiple strains. Taken together, our results show that signal summation describes the composition of a model prokaryotic transcriptome

Cancer cells exploit an orphan RNA to drive metastatic progression.

Here we performed a systematic search to identify breast-cancer-specific small noncoding RNAs, which we have collectively termed orphan noncoding RNAs (oncRNAs). We subsequently discovered that one of these oncRNAs, which originates from the 3' end of TERC, acts as a regulator of gene expression and is a robust promoter of breast cancer metastasis. This oncRNA, which we have named T3p, exerts its prometastatic effects by acting as an inhibitor of RISC complex activity and increasing the expression of the prometastatic genes NUPR1 and PANX2. Furthermore, we have shown that oncRNAs are present in cancer-cell-derived extracellular vesicles, raising the possibility that these circulating oncRNAs may also have a role in non-cell autonomous disease pathogenesis. Additionally, these circulating oncRNAs present a novel avenue for cancer fingerprinting using liquid biopsies

MAGE-A cancer/testis antigens inhibit MDM2 ubiquitylation function and promote increased levels of MDM4

Melanoma antigen A (MAGE-A) proteins comprise a structurally and biochemically similar sub-family of Cancer/Testis antigens that are expressed in many cancer types and are thought to contribute actively to malignancy. MAGE-A proteins are established regulators of certain cancer-associated transcription factors, including p53, and are activators of several RING finger-dependent ubiquitin E3 ligases. Here, we show that MAGE-A2 associates with MDM2, a ubiquitin E3 ligase that mediates ubiquitylation of more than 20 substrates including mainly p53, MDM2 itself, and MDM4, a potent p53 inhibitor and MDM2 partner that is structurally related to MDM2. We find that MAGE-A2 interacts with MDM2 via the N-terminal p53-binding pocket and the RING finger domain of MDM2 that is required for homo/hetero-dimerization and for E2 ligase interaction. Consistent with these data, we show that MAGE-A2 is a potent inhibitor of the E3 ubiquitin ligase activity of MDM2, yet it does not have any significant effect on p53 turnover mediated by MDM2. Strikingly, however, increased MAGE-A2 expression leads to reduced ubiquitylation and increased levels of MDM4. Similarly, silencing of endogenous MAGE-A expression diminishes MDM4 levels in a manner that can be rescued by the proteasomal inhibitor, bortezomid, and permits increased MDM2/MDM4 association. These data suggest that MAGE-A proteins can: (i) uncouple the ubiquitin ligase and degradation functions of MDM2; (ii) act as potent inhibitors of E3 ligase function; and (iii) regulate the turnover of MDM4. We also find an association between the presence of MAGE-A and increased MDM4 levels in primary breast cancer, suggesting that MAGE-A-dependent control of MDM4 levels has relevance to cancer clinically

CMB Telescopes and Optical Systems

The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

Amputation-induced reactive oxygen species are required for successful Xenopus tadpole tail regeneration.

Understanding the molecular mechanisms that promote successful tissue regeneration is critical for continued advancements in regenerative medicine. Vertebrate amphibian tadpoles of the species Xenopus laevis and Xenopus tropicalis have remarkable abilities to regenerate their tails following amputation, through the coordinated activity of numerous growth factor signalling pathways, including the Wnt, Fgf, Bmp, Notch and TGF-β pathways. Little is known, however, about the events that act upstream of these signalling pathways following injury. Here, we show that Xenopus tadpole tail amputation induces a sustained production of reactive oxygen species (ROS) during tail regeneration. Lowering ROS levels, using pharmacological or genetic approaches, reduces the level of cell proliferation and impairs tail regeneration. Genetic rescue experiments restored both ROS production and the initiation of the regenerative response. Sustained increased ROS levels are required for Wnt/β-catenin signalling and the activation of one of its main downstream targets, fgf20 (ref. 7), which, in turn, is essential for proper tail regeneration. These findings demonstrate that injury-induced ROS production is an important regulator of tissue regeneration

Elevated O-GlcNAc-dependent signaling through inducible mOGT expression selectively triggers apoptosis

O-linked N-acetylglucosamine transferase (OGT) catalyzes O-GlcNAc addition to numerous cellular proteins including transcription and nuclear pore complexes and plays a key role in cellular signaling. One differentially spliced isoform of OGT is normally targeted to mitochondria (mOGT) but is quite cytotoxic when expressed in cells compared with the ncOGT isoform. To understand the basis of this selective cytotoxicity, we constructed a fully functional ecdysone-inducible GFP–OGT. Elevated GFP–OGT expression induced a dramatic increase in intracellular O-GlcNAcylated proteins. Furthermore, enhanced OGT expression efficiently triggered programmed cell death. Apoptosis was dependent upon the unique N-terminus of mOGT, and its catalytic activity. Induction of mOGT expression triggered programmed cell death in every cell type tested including INS-1, an insulin-secreting cell line. These studies suggest that deregulated activity of the mitochondrially targeted mOGT may play a role in triggering the programmed cell death observed with diseases such as diabetes mellitus and neurodegeneration