Root uptake of lipophilic zinc-rhamnolipid complexes

This study investigated the formation and plant uptake of lipophilic metal-rhamnolipid complexes. Monorhamnosyl and dirhamnosyl rhamnolipids formed lipophilic complexes with copper (Cu), manganese (Mn), and zinc (Zn). Rhamnolipids significantly increased Zn absorption by Brassica napus var. Pinnacle roots in 65Zn-spiked ice-cold solutions, compared with ZnSO4 alone. Therefore, rhamnolipid appeared to facilitate Zn absorption via a nonmetabolically mediated pathway. Synchrotron XRF and XAS showed that Zn was present in roots as Zn-phytate-like compounds when roots were treated with Zn-free solutions, ZnSO4, or Zn-EDTA. With rhamnolipid application, Zn was predominantly found in roots as the Zn-rhamnolipid complex. When applied to a calcareous soil, rhamnolipids increased dry matter production and Zn concentrations in durum (Triticum durum L. cv. Balcali-2000) and bread wheat (Triticum aestivum L. cv. BDME-10) shoots. Rhamnolipids either increased total plant uptake of Zn from the soil or increased Zn translocation by reducing the prevalence of insoluble Zn-phytate-like compounds in roots

Southern California Seismic Network Update

The authoritative region of the Southern California Seismic Network (SCSN) extends across southern California, from the U.S./Mexico international border to Coalinga and Owens Valley in central California (Figure 1). This area contains almost 20 million inhabitants, including two of the ten largest cities in the United States (Los Angeles and San Diego) and the two largest harbors (Los Angeles and Long Beach) in the nation. SCSN also reports on earthquakes in Baja California, which could potentially cause damage in the U.S. More than fifty earthquakes (not including aftershocks) are felt each year, and an average of 1.5 events per year are potentially damaging (magnitude greater than 5.0). Immediately after a moderate or large earthquake, SCSN provides information about the size, location, and distribution of ground shaking. Emergency managers use this information to coordinate rescue operations, guide inspectors in the search for damage, and satisfy the public's need for information. The historical record of earthquake occurrences in California is important to insurers, geotechnical engineers, and city planners

Understanding arsenic dynamics in agronomic systems to predict and prevent uptake by crop plants

This review is on arsenic in agronomic systems, and covers processes that influence the entry of arsenic into the human food supply. The scope is from sources of arsenic (natural and anthropogenic) in soils, biogeochemical and rhizosphere processes that control arsenic speciation and availability, through to mechanisms of uptake by crop plants and potential mitigation strategies. This review makes a case for taking steps to prevent or limit crop uptake of arsenic, wherever possible, and to work toward a long-term solution to the presence of arsenic in agronomic systems. The past two decades have seen important advances in our understanding of how biogeochemical and physiological processes influence human exposure to soil arsenic, and this must now prompt an informed reconsideration and unification of regulations to protect the quality of agricultural and residential soils

mRNA regulation in the "C. elegans" germ line

The C. elegans germ line relies heavily on post-transcriptional regulation of gene expression but the scale of mRNA regulation in the germ line is still unknown. Germ cells initially divide mitotically, they then enter meiosis and finally differentiate into oocytes. Transcription ceases during oogenesis and does not get reactivated until the early embryo. The oocyte-to-embryo transition (OET) encompassing oocyte maturation, fertilization and early embryogenesis, therefore solely depends on maternal factors. Maternal mRNA storage describes the repression and stabilization of these factors until they are needed. At the four-cell stage, somatic blastomeres become dependent on zygotic transcription and at the same time a subgroup of maternal mRNAs (class II maternal mRNAs) gets specifically degraded. Many developmental decisions in the germ line are regulated by RNA binding proteins (RBPs). A crucial regulator is the STAR domain protein GLD-1, which is expressed in the central gonad. GLD-1 regulates many of the developmental decisions in the germ line and loss of GLD-1 prevents oogenesis and leads instead to the development of a proliferative tumor. GLD-1 binds a large number of mRNAs, and is known to repress the translation of various transcripts but the mechanism by which it does so is unknown. We found that translation initiation of many germline mRNAs is repressed, and that GLD-1 globally represses translation initiation of its targets. Importantly, we revealed an additional role of GLD-1 in stabilizing a large number of its bound mRNAs, suggesting that GLD-1 plays a central role in maternal mRNA storage. While we could not detect an interaction between GLD-1 and translation initiation factors, we observed that GLD-1 associates with components of a conserved germline RNP complex. These components include the polyA binding protein (PABP), Y-box proteins, the Sm-like protein CAR-1 and the DDX6 helicase CGH-1, which has recently been implicated in maternal mRNA protection. Interestingly we found that while CGH-1 does not influence the translational repression of investigated GLD-1 targets, CGH-1 and GLD-1 stabilize a common set of transcripts. Remarkably, these co-regulated messages nearly exclusively encode for mRNAs that are required for the oocyte-to-embryo transition. We therefore propose a two-step model where GLD-1 binding prevents translation initiation and primes many targets for CGH-1-dependent mRNA stabilization, ultimately leading to mRNA storage

Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil

Citation: Baker, Lucas R., Gary M. Pierzynski, Ganga M. Hettiarachchi, Kirk G. Scheckel, and Matthew Newville. “Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil.” Journal of Environmental Quality 43, no. 2 (2014): 488–97. https://doi.org/10.2134/jeq2013.07.0281.The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that the differences in the efficacy of Pb stabilization in contaminated soils on fluid or granular P amendment addition is due to different P reaction processes in and around fertilizer granules and fluid droplets. We used a combination of several synchrotron-based techniques (i.e., spatially resolved micro-X-ray fluorescence, micro-X-ray absorption near-edge structure spectroscopy, and micro-X-ray diffraction) to speciate Pb at two incubation times in a smelter-contaminated soil on addition of several fluid and granular P amendments. The results indicated that the Pb phosphate mineral plumbogummite was an intermediate phase of pyromorphite formation. Additionally, all fluid and granular P sources were able to induce Pb phosphate formation, but fluid phosphoric acid (PA) was the most effective with time and distance from the treatment. Granular phosphate rock and triple super phosphate (TSP) amendments reacted to generate Pb phosphate minerals, with TSP being more effective at greater distances from the point of application. As a result, PA and TSP were the most effective P amendments at inducing Pb phosphate formation, but caution needs to be exercised when adding large amounts of soluble P to the environment

Trying something new: Understanding the common practices of reforming nursing education

What are the common reforming practices of teachers when they reform nursing education? How is cultivating thinking an important reforming practice in nursing education that moves beyond teaching critical thinking? Do the Concernful Practices of Schooling Learning Teaching reveal reforming practices that illuminate engendering community as central to creating and sustaining innovation? This interpretive phenomenological and Heideggerian hermeneutical study describes two themes (common practices) of reforming nursing education: Cultivating Thinking and Enacting the Concernful Practices: Making Visible How Innovation Arises. A pattern, Unlearning and Becoming, one of the Concernful Practices, was of central importance in this study. It describes how teachers and students seek experiences where they unlearn past pedagogical practices and explore new ways of thinking and creating egalitarian communities in reforming nursing education. This study was part of a larger multi-media distance desktop faculty development study in the interpretive pedagogccs conducted by Dr. Nancy Diekelmann at the University of Wisconsin-Madison School of Nursing. In the Diekelmann study, trying something new emerged as a common practice describing pedagogical reform. In my dissertation research, I extend Diekelmann\u27s research by investigating trying something new through interviewing 15 teachers and 9 students in nursing education for their experiences of reforming in nursing education. The data I collected and hermeneutically analyzed revealed the two themes, and the pattern described in this study, and proffer reforming practices that teachers and students can extend, enhance, and sustain. Conversely, my study offers new understandings of reforming practices teachers and students should abolish because they are oppressive, disparaging, and impede reform

Functional characterization of C. elegans Y-box-binding proteins reveals tissue-specific functions and a critical role in the formation of polysomes

The cold shock domain is one of the most highly conserved motifs between bacteria and higher eukaryotes. Y-box-binding proteins represent a subfamily of cold shock domain proteins with pleiotropic functions, ranging from transcription in the nucleus to translation in the cytoplasm. These proteins have been investigated in all major model organisms except Caenorhabditis elegans. In this study, we set out to fill this gap and present a functional characterization of CEYs, the C. elegans Y-box-binding proteins. We find that, similar to other organisms, CEYs are essential for proper gametogenesis. However, we also report a novel function of these proteins in the formation of large polysomes in the soma. In the absence of the somatic CEYs, polysomes are dramatically reduced with a simultaneous increase in monosomes and disomes, which, unexpectedly, has no obvious impact on animal biology. Because transcripts that are enriched in polysomes in wild-type animals tend to be less abundant in the absence of CEYs, our findings suggest that large polysomes might depend on transcript stabilization mediated by CEY protein

Imagine

Voices from the Incarcerated

A Poem from the Heart

Voices of the Incarcerate