The variations of NPK of cowpea (Vigna unguiculata (L) Walp) leaves with tillage,plant maturity and flooding on a clay soil

Summary The NPK concentrations in cowpea leaves (cv California Blackeye No. 5) with stage of plant development did not vary significantly with tillage treatment but several features of the concentration of these different ions with age, stage of plant development, incidence of flooding and soil water content are significant.In the major rainy season when soil water content was adequate and seldom above field capacity, there was an almost linear increase in the concentration of N and P in the leaves up to 56 days after planting which coincided with fruit development. This suggested that the accumulation of N and P do take place after flowering which occurred 39 days after planting. The pattern of accumulation of N and P in the minor rainy season suggested that flooding and the occurrence of prolonged soil moisture contents above field capacity suppressed the accumulation of these two nutrients. Potassium accumulation was high in the early stages of cowpea growth and declined with age of the crop. Flooding and high soil moisture contents seem to have had little or no effect on potassium accumulation in the leaves. The pattern of accumulation of N and P suggests that the supply of these nutrients to the cowpea plant must remain high up to fruit development and that additional N and P would need to be added to the soil after a flooding event or when the soil moisture content is above field capacity for prolonged periods.     

Evaluating the Efficacy of Equine Therapy Among At-risk Youth: A Meta-analysis

The present meta-analysis examined the efficacy of equine therapy among an at-risk youth population. Seven studies quantitatively assessed the treatment effects following involvement in an equine therapy program. The random effects model was used to aggregate each study into an overall effect size. Seven effect sizes were included in the pre-versus post-comparison analysis. The results indicate a medium effect size (g = 0.714, p < 0.001, 95% CI [0.364, 1.064]). Five effect sizes were included in the treat-ment versus control comparison analysis. The results also indicate a medium effect size (g = 0.402, p = 0.002, 95% C.I. [0.149, 0.655]). Lack of consis-tently reported study variables across studies was a limitation that resulted in the inability to run moderator analyses. However, the results indicate that equine therapy is a viable alternative to conventional intervention strategies among at-risk youth.     

ATR kinase activity regulates the intranuclear translocation of ATR and RPA following ionizing radiation

Upon damage of DNA in eukaryotic cells, several repair and checkpoint proteins undergo a dramatic intranuclear relocalization, translocating to nuclear foci thought to represent sites of DNA damage and repair. Examples of such proteins include the checkpoint kinase ATR (ATM and Rad3-related) as well as replication protein A (RPA), a single-stranded DNA binding protein required in DNA replication and repair. Here, we used a microscopy-based approach to investigate whether the damage-induced translocation of RPA is an active process regulated by ATR. Our data show that in undamaged cells, ATR and RPA are uniformly distributed in the nucleus or localized to promyelocytic leukemia protein (PML) nuclear bodies. In cells treated with ionizing radiation, both ATR and RPA translocate to punctate, abundant nuclear foci where they continue to colocalize. Surprisingly, an ATR mutant that lacks kinase activity fails to relocalize in response to DNA damage. Furthermore, this kinase-inactive mutant blocks the translocation of RPA in a cell cycle-dependent manner. These observations demonstrate that the kinase activity of ATR is essential for the irradiation-induced release of ATR and RPA from PML bodies and translocation of ATR and RPA to potential sites of DNA damage.     

Enforced proximity in the function of a famous scaffold

Recent studies by Park, Zarrinipar, and Lim with reengineered Ste5 scaffold proteins underscore the fundamental importance of proximity in enzyme regulation and of keeping a proper distance for maintaining signaling specificity.     

The Characterization of Twenty Sequenced Human Genomes

We present the analysis of twenty human genomes to evaluate the prospects for identifying rare functional variants that contribute to a phenotype of interest. We sequenced at high coverage ten “case” genomes from individuals with severe hemophilia A and ten “control” genomes. We summarize the number of genetic variants emerging from a study of this magnitude, and provide a proof of concept for the identification of rare and highly-penetrant functional variants by confirming that the cause of hemophilia A is easily recognizable in this data set. We also show that the number of novel single nucleotide variants (SNVs) discovered per genome seems to stabilize at about 144,000 new variants per genome, after the first 15 individuals have been sequenced. Finally, we find that, on average, each genome carries 165 homozygous protein-truncating or stop loss variants in genes representing a diverse set of pathways.     

SHPRH and HLTF act in a damage-specific manner to coordinate different forms of postreplication repair and prevent mutagenesis

Postreplication repair (PRR) pathways play important roles in restarting stalled replication forks and regulating mutagenesis. In yeast, Rad5-mediated damage avoidance and Rad18-mediated translesion synthesis (TLS) are two forms of PRR. Two Rad5-related proteins, SHPRH and HLTF, have been identified in mammalian cells, but their specific roles in PRR are unclear. Here, we show that HLTF and SHPRH suppress mutagenesis in a damage-specific manner, preventing mutations induced by UV and MMS, respectively. Following UV, HLTF enhances PCNA monoubiquitination and recruitment of TLS polymerase η, while also inhibiting SHPRH function. In contrast, MMS promotes the degradation of HLTF and the interactions of SHPRH with Rad18 and polymerase κ. Our data suggest not only that cells differentially utilize HLTF and SHPRH for different forms of DNA damage, but also, surprisingly, that HLTF and SHPRH may coordinate the two main branches of PRR to choose the proper bypass mechanism for minimizing mutagenesis.     

Calcium and mitochondria

The literature suggests that the physiological functions for which mitochondria sequester Ca(2+) are (1). to stimulate and control the rate of oxidative phosphorylation, (2). to induce the mitochondrial permeability transition (MPT) and perhaps apoptotic cell death, and (3). to modify the shape of cytosolic Ca(2+) pulses or transients. There is strong evidence that intramitochondrial Ca(2+) controls both the rate of ATP production by oxidative phosphorylation and induction of the MPT. Since the results of these processes are so divergent, the signals inducing them must not be ambiguous. Furthermore, as pointed out by Balaban [J. Mol. Cell. Cardiol. 34 (2002 ) 11259-11271], for any repetitive physiological process dependent on intramitochondrial free Ca(2+) concentration ([Ca(2+)](m)), a kind of intramitochondrial homeostasis must exist so that Ca(2+) influx during the pulse is matched by Ca(2+) efflux during the period between pulses to avoid either Ca(2+) buildup or depletion. In addition, mitochondrial Ca(2+) transport modifies both spatial and temporal aspects of cytosolic Ca(2+) signaling. Here, we look at the amounts of Ca(2+) necessary to mediate the functions of mitochondrial Ca(2+) transport and at the mechanisms of transport themselves in order to set up a hypothesis about how the mechanisms carry out their roles. The emphasis here is on isolated mitochondria and on general mitochondrial properties in order to focus on how mitochondria alone may function to fulfill their physiological roles even though the interactions of mitochondria with other organelles, particularly with endoplasmic and sarcoplasmic reticulum [Sci. STKE re1 (2004) 1-9], may also influence this story.     

New ionic derivatives of betulinic acid as highly potent anti-cancer agents

Betulinic acid is a natural compound with high in vitro cytotoxicity toward many cancer cells. However, the poor water solubility of this compound hampers an effective in vivo cancer study. We prepared new ionic derivatives of betulinic acid with higher water solubilities, without losing the structural integrity and functionality of this compound. As a result, these new ionic derivatives have shown much higher inhibitory effects against different cancer cell lines such as melanoma A375, neuroblastoma SH-SY5Y and breast adenocarcinoma MCF7. For A375 cell lines, the derivative 5 exhibited a low IC(50) value of 36 μM (vs 154 μM for betulinic acid); for MCF7 cell lines, the derivative 5 also exhibited a low IC(50) value of 25 μM (vs 112 μM for betulinic acid). The high cytotoxicity of these new derivatives can be linked to their greatly improved water solubility. Our assay method used little DMSO in aiding the dissolution of these derivatives to demonstrate the advantage of improved water solubility and to mimic the in vivo study conditions. The cell viability studies based on both MTT and LDH assay methods have confirmed the high inhibitory effect of our ionic derivatives of betulinic acid (particularly 4 and 5) against different cancer cells.