Tensor product of dualizing complexes over a field

Let $k$ be a field, and let $X,Y$ be two locally noetherian $k$-schemes (respectively $k$-formal schemes) with dualizing complexes $R_X$ and $R_Y$ respectively. We show that $R_X \boxtimes_{k} R_Y$ (respectively its derived completion) is a dualizing complex over $X\times_{k} Y$ if and only if $X\times_{k} Y$ is locally noetherian of finite Krull dimension.Comment: 13 pages, final version, to appear in the Journal of Commutative Algebr

Experimental Verification of a Predicted Intronic MicroRNA in Human NGFR Gene with a Potential Pro-Apoptotic Function

Neurotrophins (NTs) are a family of secreted growth factor proteins primarily involved in the regulation of survival and appropriate development of neural cells, functioning by binding to their specific (TrkA, TtkB, and TrkC) and/or common NGFR receptor. NGFR is the common receptor of NTs, binding with low-affinity to all members of the family. Among different functions assigned to NGFR, it is also involved in apoptosis induction and tumorigenesis processes. Interestingly, some of the functions of NGFR appear to be ligand-independent, suggesting a probable involvement of non-coding RNA residing within the sequence of the gene. Here, we are reporting the existence of a conserved putative microRNA, named Hsa-mir-6165 [EBI accession#: FR873488]. Transfection of a DNA segment corresponding to the pre-mir-6165 sequence in Hela cell line caused the generation of mature exogenous mir-6165 (a ∼200,000 fold overexpression). Furthermore, using specific primers, we succeeded to detect the endogenous expression of mir-6165 in several glioma cell lines and glioma primary tumors known to express NGFR. Similar to the pro-apoptotic role of NGFR in some cell types, overexpression of pre-mir-6165 in U87 cell line resulted in an elevated rate of apoptosis. Moreover, coordinated with the increased level of mir-6165 in the transfected U87 cell line, two of its predicted target genes (Pkd1 and DAGLA) were significantly down-regulated. The latter findings suggest that some of the previously attributed functions of NGFR could be explained indirectly by co-transcription of mir-6165 in the cells

Chlamydia trachomatis Infection and Anti-Hsp60 Immunity: The Two Sides of the Coin

Chlamydia trachomatis (CT) infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60) and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human) may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician

An Anomalous Type IV Secretion System in Rickettsia Is Evolutionarily Conserved

Bacterial type IV secretion systems (T4SSs) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein) translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir). However, the Rickettsia T4SS has not been functionally characterized for its role in symbiosis/virulence, and none of its substrates are known.Superimposition of T4SS structural/functional information over previously identified Rickettsia components implicate a functional Rickettsia T4SS. virB4, virB8 and virB9 are duplicated, yet only one copy of each has the conserved features of similar genes in other T4SSs. An extraordinarily duplicated VirB6 gene encodes five hydrophobic proteins conserved only in a short region known to be involved in DNA transfer in A. tumefaciens. virB1, virB2 and virB7 are newly identified, revealing a Rickettsia T4SS lacking only virB5 relative to the vir archetype. Phylogeny estimation suggests vertical inheritance of all components, despite gene rearrangements into an archipelago of five islets. Similarities of Rickettsia VirB7/VirB9 to ComB7/ComB9 proteins of epsilon-proteobacteria, as well as phylogenetic affinities to the Legionella lvh T4SS, imply the Rickettsiales ancestor acquired a vir-like locus from distantly related bacteria, perhaps while residing in a protozoan host. Modern modifications of these systems likely reflect diversification with various eukaryotic host cells.We present the rvh (Rickettsiales vir homolog) T4SS, an evolutionary conserved transporter with an unknown role in rickettsial biology. This work lays the foundation for future laboratory characterization of this system, and also identifies the Legionella lvh T4SS as a suitable genetic model

Effects of Time and Rate of Nitrogen Fertilizer Application on NUE and Yield of Rapeseed )Brassica napus L.( as Second Crop in Paddy Fields

To determine the proper nitrogen fertilizer rates and its application time for achieving to high nitrogen use efficiency and grain yield of rapeseed cultivar Hyola 401, a research work was carried out at paddy fields of Rice Research Institute of Iran in Rasht during 2005-2007 cropping seasons. A factorial experiment was conducted in randomized complete blocks design with three replications. The first factor was nitrogen fertilizer rate at five levels of 0, 60, 120, 180 and 240 kg N ha-1 from urea source. Second factor was fertilizer application time at five levels of all fertilizer at planting; 1/3 at planting + 2/3 in stem elongation; 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering; 1/3 in 3-4 leaf stages + 1/3 in stem elongation +1/3 before flowering and 1/4 at planting + 1/4 in 3-4 leaf stages +1/4 in stem elongation + 1/4 before flowering.  In this experiment, some important traits such as oil content, oil and grain yields, nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), nitrogen physiological efficiency (NPE) and nitrogen apparent recovery fraction (NRF) were calculated. The results of the combined analysis of variance showed Significant difference was observed between nitrogen rates in all traits except in seed oil content. Application of 60 kg N ha-1 produced the maximum NAE, NUE and NPE with values of 12.45, 25.54 and 35.92 kg kg-1, respectively and application of 240 and 180 kg N ha-1 with average production of 2505 and 2596 kg ha-1, respectively showed the highest grain yield. Nitrogen application time of 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering had the highest grain yield and NRF with average of 2155.3 kg ha-1 and 38.91 %. According to the results of the present experiment, it seems application of 180 kg N ha-1 produced the maximum NRF and grain and oil yields. Also, third application time decreases nitrogen loss resulting from leaching, denitrification and sublimation due to availability and proper use of nitrogen during plant growth and increases rapeseed yield by increase in nitrogen absorption

Effect of Time and Concentration of Nitrogen Fertilizer Foliar Spraying as Complementary of Soil Nutrition on Dry Matter Remobilization and Seed and Oil Yield of Rapeseed (Brassica napus L.)

In order to evaluate the effect of concentration and time of foliar spraying of nitrogen fertilizer as complementary of soil nutrition on dry matter remobilization and seed and oil yield of rapeseed (Hyola401), an experiment was conducted in complete randomized block design with 16 treatments and three replications in two years (2008-2010) in Rice Research Institute of Iran (Rasht). In this experiment, nitrogen concentration (from urea source) at two levels (5 and 10 ppm) and application time in seven levels including 1-seedling stage at 6-8 leaves 2: beginning of stem elongation, 3: prior to flowering, 4: 6-8 leaves + stem elongation, 5: 6-8 leaves + prior to flowering, 6: stem elongation+ prior to flowering, 7: 6-8 leaves + stem elongation+ prior to flowering plus two control treatments including zero nitrogen fertilizer and conventional fertilization (180 kg.ha-1) at seed sowing, stem elongation and prior to flowering in equal rates, were considered. Results showed that foliar application of nitrogen (10 ppm) in 6-8 leaves+stem elongation+prior to flowering stage had the highest dry matter remobilization (612.2 g.m-2), current rate of photosynthesis (3074 g.m-2), and grain yield (3686.2 kg.ha-1). Calculation of regression coefficients showed that dry matter remobilization had linear and positive relationship with grain yield (r2=0.95**). According to the results of the present experiment, it seems that foliar application of nitrogen (10 ppm) at 6-8 leaves + stem elongation+ prior to flowering stage and stem elongation+ prior to flowering stage increases dry matter remobilization, seed and oil yields

Effect of Different Nitrogen Levels on Current Rate of Photosynthesis and Dry Matter Remobilization inTwo Cultivars of Rapeseed (Brassica napus L.)

To study the effect of different amounts of nitrogen fertilizer on dry matter remobilization in two cultivars of rapeseed a factorial experiment was conducted in complete randomized block design with three replications in the 2010-2012 years in Rasht, Iran. The experimental factors were two cultivars of rapeseed (Sarigol and Hayola308) and nitrogen fertilizer rate (from urea source) at five levels of 0, 50, 100, 150 and 200 kg ha-1 of N as 1/3 at planting 1/3 at stem elongation 1/3 before flowering. The results indicated that in the second year a higher dry matter remobilization (400 g m-2), current photosynthesis (1750 g m-2) and grain and oil yield (2149.8 and 927.2 kg ha-1 respectively) was achieved. Between nitrogen rates, application of 200 kg N ha-1 led to the highest current photosynthesis, dry matter remobilization, grain and oil yield. Hayola308 cultivar with 150 and 200 kg ha-1 of N indicated the highest oil yield (1518 and 1333 kg ha-1, respectively) and dry matter remobilization (531.5 and 492.4 g m-2 respectively). According to the results of the present experiment, it seems that cultivar Hayola308 with application of 150 kg N ha-1 can increase the current rate of photosynthesis, dry matter remobilization and oil yield of rapeseed, due to increase in the photosynthetic surfaces