Linkage of modules over Cohen-Macaulay rings

Inspired by the works in linkage theory of ideals, the concept of sliding depth of extension modules is defined to prove the Cohen-Macaulyness of linked module if the base ring is merely Cohen-Macaulay. Some relations between this new condition and other module-theory conditions such as G-dimension and sequentially Cohen-Macaulay are established. By the way several already known theorems in linkage theory are improved or recovered by new approaches.Comment: 12 Page

Plane Cremona maps: saturation and regularity of the base ideal

One studies plane Cremona maps by focusing on the ideal theoretic and homological properties of its homogeneous base ideal ("indeterminacy locus"). The {\em leitmotiv} driving a good deal of the work is the relation between the base ideal and its saturation. As a preliminary one deals with the homological features of arbitrary codimension 2 homogeneous ideals in a polynomial ring in three variables over a field which are generated by three forms of the same degree. The results become sharp when the saturation is not generated in low degrees, a condition to be given a precise meaning. An implicit goal, illustrated in low degrees, is a homological classification of plane Cremona maps according to the respective homaloidal types. An additional piece of this work relates the base ideal of a rational map to a few additional homogeneous "companion" ideals, such as the integral closure, the $\boldsymbol\mu$-fat ideal and a seemingly novel ideal defined in terms of valuations.Comment: New version only 36 pages, one typo correcte

Open loci of ideals with applications to Birational maps

In this work we show that the loci of ideals in principal class, ideals of grade at least two, and ideals of maximal analytic spread are Zariski open sets in the parameter space. As an application, we show that the set of birational maps of {\it clear polynomial degree} $d$ over an arbitrary projective variety $X$, denoted by \Bir(X)_{d}, is a constructible set. This extends a previous result by Blanc and Furter.Comment: 19 pg

A note on quasi-Gorenstein rings

In this paper, after giving a criterion for a Noetherian local ring to be quasi-Gorenstein, we obtain some sufficient conditions for a quasi- Gorenstein ring to be Gorenstein. In the course, we provide a slight generalization of a theorem of Evans and Griffith.Comment: To appear in Arch. Mat

Seroepidemiology of Toxoplasma gondii infection in immunodeficiency patients in Kashan and Qom during 2014-2015

Background: Toxoplasma gondii is an opportunistic parasitic protozoon, which is a causative agent of serious complications such as encephalitis in immunodeficiency patients. Considering insufficient data on toxoplasmosis in these patients, the present study was conducted to determine the seroepidemiology of T. gondii among immunodeficiency patients. Materials and Methods: This cross-sectional study was conducted on cancer, ADIS, hemodialysis and renal transplant patients (case group) and healthy persons (control group) in Kashan and Qom cities. Totally, 317 serum samples were collected from the case group and 120 samples from the control group. The ELISA method was used to determine the anti-T. gondii IgG and IgM antibodies. Results: Totally, 60.3 of the samples from the case and 33.3 from the control groups were positive for anti-T. gondii IgG (P<0.001). In the case group, only 2 persons (0.6) were positive for anti-T. gondii IgM. The anti-T. gondii IgG detected in immunodeficiency patients was 55.2 in Kashan and 68 in Qom, which were higher than in the control group (P<0.001, P<0.006, respectively). The highest prevalence of T. gondii were seen in 40-59 years old (49.8) and illiterate (60) patients. There was a meaningful correlation between toxoplasmosis and blurry vision and dermal rash (P=0.001 and P=0.003, respectively). Conclusion: The prevalence of T. gondii was higher in different immunodeficiency patients compared to healthy persons. Screening examinations were recommended for the diagnosis and treatment of patients to prevent serious side-effects and health education

Selective β2 adrenergic agonist increases Cx43 and miR-451 expression via cAMP-Epac

It has been demonstrated that connexin 43 (Cx43) and microRNAs have significant roles in glioma. Cyclic adenosine monophosphate (cAMP) is suggested to be a regulator of connexins and microRNAs. However, it remains elusive whether cAMP and exchange protein directly activated by cAMP (Epac2), have a regulatory effect on Cx43 and microRNA-451 (miR-451) in astrocytoma cells. We treated 1321N1 astrocytoma cells with a selective β2 adrenergic agonist and a selective Epac activator with and without adenyl cyclase and protein kinase A inhibition. Cx43 and miR-451 expression were measured. Next, we evaluated the effect of miR-451 overexpression on Cx43 expression. Cell proliferation was measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results demonstrated that cAMPE-pac2 increased Cx43 and miR-451 expression. However, the alteration of miR-451 expression required a higher dose of drugs. Overexpression of miR-451 had no significant effect on Cx43 expression. The MTT assay showed that cAMP-Epac stimulation and miR-451 overexpression had a synergic inhibitory effect on cell proliferation. These findings may expand our understanding of the molecular biology of glioma and provide new potential therapeutic targets