A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions

Conservation agriculture involves reduced tillage, permanent soil cover and crop rotations to enhance soil fertility and to supply food from a dwindling land resource. Recently, conservation agriculture has been promoted in Southern Africa, mainly for maize-based farming systems. However, maize yields under rain-fed conditions are often variable. There is therefore a need to identify factors that influence crop yield under conservation agriculture and rain-fed conditions. Here, we studied maize grain yield data from experiments lasting 5 years and more under rain-fed conditions. We assessed the effect of long-term tillage and residue retention on maize grain yield under contrasting soil textures, nitrogen input and climate. Yield variability was measured by stability analysis. Our results show an increase in maize yield over time with conservation agriculture practices that include rotation and high input use in low rainfall areas. But we observed no difference in system stability under those conditions. We observed a strong relationship between maize grain yield and annual rainfall. Our meta-analysis gave the following findings: (1) 92% of the data show that mulch cover in high rainfall areas leads to lower yields due to waterlogging; (2) 85% of data show that soil texture is important in the temporal development of conservation agriculture effects, improved yields are likely on well-drained soils; (3) 73% of the data show that conservation agriculture practices require high inputs especially N for improved yield; (4) 63% of data show that increased yields are obtained with rotation but calculations often do not include the variations in rainfall within and between seasons; (5) 56% of the data show that reduced tillage with no mulch cover leads to lower yields in semi-arid areas; and (6) when adequate fertiliser is available, rainfall is the most important determinant of yield in southern Africa. It is clear from our results that conservation agriculture needs to be targeted and adapted to specific biophysical conditions for improved impact

SMAR1 binds to T(C/G) repeatvand inhibits tumor progression by regulating miR-371-373 cluster

Chromatin architecture and dynamics are regulated by various histone and non-histone proteins. The matrix attachment region binding proteins (MARBPs) play a central role in chromatin organization and function through numerous regulatory proteins. In the present study, we demonstrate that nuclear matrix protein SMAR1 orchestrates global gene regulation as determined by massively parallel ChIPsequencing. The study revealed that SMAR1 binds to T(C/G) repeat and targets genes involved in diverse biological pathways. We observe that SMAR1 binds and targets distinctly different genes based on the availability of p53. Our data suggest that SMAR1 binds and regulates one of the imperative microRNA clusters in cancer and metastasis, miR-371-373. It negatively regulates miR-371-373 transcription as confirmed by SMAR1 overexpression and knockdown studies. Further, deletion studies indicate that a ~200 bp region in the miR-371-373 promoter is necessary for SMAR1 binding and transcriptional repression. Recruitment of HDAC1/mSin3A complex by SMAR1, concomitant with alteration of histone marks results in downregulation of the miRNA cluster. The regulation of miR-371-373 by SMAR1 inhibits breast cancer tumorigenesis and metastasis as determined by in vivo experiments. Overall, our study highlights the binding of SMAR1 to T(C/G) repeat and its role in cancer through miR-371-37

p53 Target Gene SMAR1 Is Dysregulated in Breast Cancer: Its Role in Cancer Cell Migration and Invasion

Tumor suppressor SMAR1 interacts and stabilizes p53 through phosphorylation at its serine-15 residue. We show that SMAR1 transcription is regulated by p53 through its response element present in the SMAR1 promoter. Upon Doxorubicin induced DNA damage, acetylated p53 is recruited on SMAR1 promoter that allows activation of its transcription. Once SMAR1 is induced, cell cycle arrest is observed that is correlated to increased phospho-ser-15-p53 and decreased p53 acetylation. Further we demonstrate that SMAR1 expression is drastically reduced during advancement of human breast cancer. This was correlated with defective p53 expression in breast cancer where acetylated p53 is sequestered into the heterochromatin region and become inaccessible to activate SMAR1 promoter. In a recent report we have shown that SMAR1 represses Cyclin D1 transcription through recruitment of HDAC1 dependent repressor complex at the MAR site of Cyclin D1 promoter. Here we show that downmodulation of SMAR1 in high grade breast carcinoma is correlated with upregulated Cyclin D1 expression. We also established that SMAR1 inhibits tumor cell migration and metastases through inhibition of TGFβ signaling and its downstream target genes including cutl1 and various focal adhesion molecules. Thus, we report that SMAR1 plays a central role in coordinating p53 and TGFβ pathways in human breast cancer

Toward Smart Implant Synthesis: Bonding Bioceramics of Different Resorbability to Match Bone Growth Rates

This work was partially funded by the European Union (Project MARMED - 2011-1/164), the Spanish Government and FEDER (CICYT MAT2006-10481) by Xunta de Galicia (CN2012/292)

Subclavian Vein Thrombosis

Subclavian vein thrombosis (SCVT) is a condition where a blood clot forms in the subclavian vein. SCVT can occur from multiple etiologies and is a potentially life-threatening pathology if not treated in a timely manner. SCVT occurs due to either a primary etiology or a secondary etiology. Primary thrombosis is further delineated as effort induced (Paget-Schroetter syndrome) or idiopathic (frequently associated with undiagnosed malignancy). Secondary subclavian vein thrombosis is associated with catheters or lines in the vein. While primary thrombosis is rare, the incidence of secondary thrombosis continues to rise as a consequence of complex cardiac devices and long term central venous catheters (CVC) placement in cancer patients. SCVT has high rates of acute mortality and long term disability without proper and timely treatment. Early diagnosis and treatment are essential in preventing fatal acute complications, such as pulmonary embolism and long term morbidity related to venous inflow restriction