107 research outputs found
Relationship between the melting Arctic Sea Ice Extent and North Atlantic Oscillation Index
Arctic Sea Ice Extent (SIE) maintains the ocean circulation at the
equilibrium and provides strong feedback in the earth's climate system. When
the Arctic Sea Ice melts in the summer, it results in the oceans absorbing and
heating up the Arctic. As Arctic SIE is melting increasing rate, the oceans
absorb and heat up further. This contributes to rising sea surface temperature,
which has a larger impact on global atmospheric pressure. Thus, the climate
scientists are alarmed that global warming will cause the polar ice caps to
melt and that may lead to a "critical instability".
In our study, we construct a phase-space using the velocity and acceleration
of the Arctic Sea Ice Extent (SIE) as two variables. From the data analysis, we
show that in recent decades the melting arctic SIE resulted in increasing
phase-space volume, i.e., the phase-line distribution function has not been
constant along the trajectories. Our aim is to investigate the effect of the
melting Arctic SIE on the climate - particularly on the North Atlantic
Oscillation (NAO) index, a measure of variability in the atmospheric pressure
at sea level. Based on a Granger causal model and a conservative Bootstrap
statistical test, we find that the changing phase-plane SIE does have a
significant (at 0.01 percent) effect on the NAO index. It indicates melting SIE
has a significant effect on the changing weather pattern of the North Atlantic
region, especially in Europe and North America. In addition, we see that the
yearly median of NAO is greater than the yearly average NAO, which indicates
that the distribution of NAO is negatively skewed, even though NAO follows
nearly a mean zero stationary process. Our statistical study hints that we will
soon see a warmer climate in Eastern USA and Northern Europe. Naturally, a
warmer northern Europe would lead to a shrinking SIE, which can be a cause of
alarm
Association between serum magnesium and obesity in postmenopausal women
Background: Obesity is a complex, multifactorial condition in which excess body weight may put a female at risk of serious health problems such as hypertension, dyslipidemia, diabetes mellitus and cardiovascular diseases. Magnesium deficiency is reported to be associated with obesity in children and adolescents. An inverse relationship has been reported between serum magnesium and estrogen levels in women. It is not known whether magnesium deficiency may have a role in genesis of obesity in women after menopause. Therefore, the present study was planned to compare serum magnesium levels in obese and non-obese postmenopausal women and to find out the relationship, if any, between serum magnesium levels and obesity.Methods: This cross-sectional study was conducted in the department of Biochemistry at National Institute of Medical Sciences and Research, Jaipur, Rajasthan on fifty subjects over a period of six months. Twenty-five obese postmenopausal women (BMI ≥ 30) having their final menstrual period at least one year prior to the study were taken as the study group and twenty-five non-obese (BMI ≤ 22.9) post-menopausal women were taken as control group. All subjects were asked to give detailed dietary history using Food Frequency Questionnaire (FFQ). Venous blood samples were collected after an overnight fast for estimation of serum total magnesium in all subjects.Results: Obese postmenopausal women had significantly higher weight (78.36±0.064kg) and BMI (32.68±1.7kg/mt2) compared to non-obese postmenopausal women (wt. 54.72±4.80kg and BMI 21.75±1.68kg/mt2). The mean±SD serum magnesium concentration found in the obese postmenopausal women was 1.40±0.45mg/dl as compared to 2.03±0.49 mg/dl in the non-obese group. Pearson’s correlation analysis showed a significant (r = -0.9) negative correlation between BMI and serum magnesium in postmenopausal women.Conclusions: Serum magnesium was lower in obese postmenopausal women as compared to that in non-obese postmenopausal women. Serum magnesium was negatively correlated with BMI. Magnesium supplementation may be useful in prevention of obesity after menopause
Heterosis study in Okra [Abelmoschus esculentus (L.) Moench] genotypes for pod yield attributes
A study was conducted at Vegetable Research Farm, Department of Horticulture, Institute of Agriculture Sciences, Banaras Hindu University, Varanasi during Spring-Summer and Rainy season of 2012 and 2013 using 12 diverse parental lines of okra and their 66 F1 hybrids (through diallel cross-excluding reciprocals) with the objective to measure the extent of heterosis over better parent and standard commercial check varieties for the purpose of judging the extent up to which heterosis can be exploited in commercial okra breeding. The extent of heterosis for five best crosses over better parent and check (48.32 % to 82.42 % and 7.13 % to 35.66 %, respectively) for yield per hectare suggested the great scope of realizing higher yield in okra through heterosis breeding. Other economic traits also recorded moderate to high level of heterosis over the better parents. The cross combination IC -282280×EC – 329380showed high heterosis over better parent and standard check for pod yield (82.42 % and 35.66 %), number of pods per plant (62.82 % and 48.54 %) and respectively. This particular cross combination eventually resulted the height magnitude of heterobeltiosis and standard heterosis for the most of the desirable growth parameters as well as yield attributing characters which may be taken for further breeding programme
Closed Form Expressions for Delay to Ramp Inputs for On-Chip VLSI RC Interconnect
In high speed digital integrated circuits, interconnects delay can be significant and should be included for accurate analysis. Delay analysis for interconnect has been done widely by using moments of the impulse response, from the explicit Elmore delay (the first moment of the impulse response) expression, to moment matching methods which creates reduced order trans impedance and transfer function approximations. However, the Elmore delay is fast becoming ineffective for deep submicron technologies, and reduced order transfer function delays are impractical for use as early-phase design metrics or as design optimization cost functions. This paper describes an approach for fitting moments of the impulse response to probability density functions so that delay can be estimated accurately at an early physical design stage. For RC trees it is demonstrated that the inverse gamma function provides a provably stable approximation. We used the PERI [13] (Probability distribution function Extension for Ramp Inputs) technique that extends delay metrics for ramp inputs to the more general and realistic non-step inputs. The accuracy of our model is justified with the results compared with that of SPICE simulations. Keywords¾ Moment Matching, On-Chip Interconnect, Probability Distribution function, Cumulative Distribution function, Delay calculation, Slew Calculation, Beta Distribution, VLSI
Association of genetic and epigenetic modification in MTHFR gene with coronary artery disease patients in North Indian population
Background: Methylene tetra hydro folate reductase (MTHFR) gene polymorphism C677T (rs180113) and DNA methylation in promoter region of MTHFR gene may contribute to the development of coronary artery disease however the results have been inconsistent across studies with different populations, so the aim of our study is to explore the association of polymorphism in MTHFR gene and methylation in promoter region with coronary artery disease (CAD) and other risk factor (lipid profile, homocysteine, vitamin B12 and folic acid levels)Â leading to CAD in of north Indian population.
Methods: Total 100 CAD patients and 100 healthy controls were enrolled in the study. Genotyping of rs1801133 SNP (C677T) is done by PCR-RFLP and DNA methylation study in promoter region by methylation specific PCR. Lipid profile analysis by automated chemistry analyzers, serum homocysteine, folic acid and vitamin B12 was assayed by ELISA.
Results: As per our finding the T allele (OR=3.03, 95% CI=1.74-5.27) and hyper methylation in promoter region of MTHFR increases the odds of coronary artery disease, (OR=3.05, 95% CI=1.7-5.6). Study participants with CT and TT genotype had significantly higher homocysteine (Hcy) (p=0.001), lower folic acid level (p=0.0), and HDL levels (p<0.0001) than those with CC genotype. The study subjects with hyper methylated promoter region have a significantly high homocystenemia levels (p=0.001).
Conclusions: The TT genotype of the MTHFR C677T gene polymorphism and hyper methylation in promoter region of MTHFR, is associated with CAD and can be useful in identification of new biomarkers, development of preventive and therapeutic strategies for CAD.
Comparison of obstetric outcomes of pregnancies after donor oocyte IVF: Three-arm age-matched retrospective cohort study
Background: Oocyte donation has become widely used as a treatment option for infertile couples. The few available studies report conflicting evidence about the risk of hypertensive disorders in donor oocyte pregnancies after adjusting for maternal age and it is unclear whether pregnancy complications and obstetric risks are due to oocyte donation or to confounding factors such as maternal age. The aim of the present study was to evaluate and compare obstetric complications between women who conceived after oocyte donation and age-matched control women with spontaneous conception and self oocyte IVF conception.Methods : The present study comprised of women aged 20-45 years conceived from oocyte donation (n=104) between 1/12/2010 to 15/10/2017. Two age-matched control groups—Self oocyte IVF (n=150) and the other containing women who conceived spontaneously (n=312) were used for comparison of obstetric and perinatal outcomes.Results: Mean maternal age was statistically significantly higher in the Donor oocyte IVF group as compared to  self oocyte ivf and spontaneous conception group. Miscarriage, first trimester bleeding, pregnancy induced hypertension and gestational diabetes mellitus was significantly higher in Donor oocyte IVF group as compared to self-oocyte and spontaneous conception group (p=0.001). Using multiple logistic regression analysis age class adjusted PIH and GDM incidence was significantly higher in donor oocyte group as compared to spontaneous conception (P=0.010).There was significant variation in perinatal outcomes between the three groups.Conclusion: Oocyte donation should be treated as an independent risk factor for miscarriage, first trimester bleeding, hypertensive disorder and gestational diabetes mellitus in pregnancy
Effect of cardiac surgery on maternal and perinatal outcome in rheumatic heart disease with pregnancy: a comparative study
Background: Rheumatic heart disease remains the commonest heart disease in India with mitral stenosis being the most common lesion and is associated with significant maternal and perinatal mortality and morbidity. The objective of this study was to compare maternal and perinatal outcome in women with rheumatic heart valvular disease who had no surgery or had percutaneous balloon mitral valvuloplasty (PBMV) or had valvular replacement surgery.Methods: It was a retrospective study in 113 women with rheumatic heart disease with various valvular lesion admitted in the hospital in previous 10 years. There were 58 (51.35%) patients without cardiac surgery (Group 1), 24 (21.23%) with PTMC (Group 2) and 31 (27.43%) with valve replacement surgery (Group 3). Maternal and perinatal outcome were compared in three groups.Results: The baseline characteristics were similar in the three group. In cardiac complications New York Heart Association (NYHA) deterioration was significantly higher (24.1%) in non-operated group (Group 1) as compared to Group 2 (12.3%) and Group 3 (16.1%). There was no difference in Group 2 and Group 3. Need of cardiac medication (digoxin) was also highest (67.2%) in Group 1 as compared to Group 2 (24.6%) (p = 0.002) and Group 3 (38.7%) (p = 0.001) but no difference in Group 2 and Group 3. Anticoagulant were given to significantly higher number (54.8% of cases in Group 3 (valve replacement) as compared to Group 1 (3.4%) and Group 2 (12.5%). There was no significant difference in obstetric events and mode of delivery in the three groups. Similarly, there was no difference in fetal outcome in the three groups as regard to mean birth weight, APGAR score, fetal growth restriction, fetal or neonatal death or congenital anomalies in the three groups.Conclusions: Cardiac surgery before or during pregnancy did not significantly improve maternal or perinatal outcome. Only cardiac events and need of medication was reduced with surgery. Hence surgery should be performed judiciously in selected cases
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Increasing Endoglin Deletion in Endothelial Cells Exacerbates the Severity of Brain Arteriovenous Malformation in Mouse.
Endoglin (ENG) mutation causes type 1 hereditary hemorrhagic telangiectasia (HHT1). HHT1 patients have arteriovenous malformations (AVMs) in multiple organs, including the brain. In mice, Eng deletion induced by R26RCreER or SM22αCre leads to AVM development in the brain and other organs. We hypothesized that an increase in Eng- negative ECs will enhance AVM severity. To increase EC Eng deletion, we used a codon-improved cre (icre), which is more potent in recombination of the floxed alleles than the wild-type (WT) cre. R26RCreER;Engf/f mice that have a Rosa promoter driving and tamoxifen (TM)-inducible WT cre expression globally, and PdgfbiCreER;Engf/f mice that have a Pdgfb promoter driving and TM-inducible icre expression in ECs were treated with three intra-peritoneal injections of TM (2.5 mg/25 g of body weight) to delete Eng globally or in the ECs. AAV-VEGF was stereotactically injected into the brain to induce brain focal angiogenesis and brain AVM. We found that icre caused more Eng deletion in the brain, indicated by a lower level of Eng proteins (p < 0.001) and fewer Eng-positive ECs (p = 0.01) than mice with WT cre. Mice with icre-mediated Eng deletion have more abnormal vessels (p = 0.02), CD68+ macrophages (p = 0.002), and hemorrhage (p = 0.04) and less vascular pericyte and smooth muscle coverage than mice with WT cre. In addition, arteriovenous shunts were detected in the intestines of icre mice, a phenotype that has not been detected in WT cre mice before. RNA-seq analysis showed that 8 out of the 10 top upregulated pathways identified by gene ontology (GO) analysis are related to inflammation. Therefore, the increase in Eng deletion in ECs exacerbates AVM severity, which is associated with enhanced inflammation. Strategies that can reduce Eng-negative ECs could be used to develop new therapies to reduce AVM severity for HHT1 patients
Molecular diversity and pathogenic variability in Colletotrichum capsici of chilli (Capsicum annuum) in Haryana
The fruit rot of chilli (Capsicum annuum L.), caused by Colletotrichum capsici, is the most serious disease of chilli in India. Fourteen isolates of C. capsici collected from different locations in Haryana state were investigated for molecular variations along with their virulence pattern. Different levels of virulence were expressed dividing isolates into four groups. Out of 33 primers, 22 exhibited DNA polymorphism producing a total of 108 bands with an average of 4.90 bands per primer. At an arbitrary cut-off at 45% similarity level of dendrogram, the isolates were clustered into two main clusters. The grouping of the isolates based on RAPDs was in general neither in agreement with their pathogenicity on different host cultivars nor with the geographical location of the isolate. The information may be helpful in improving chilli fruit rot resistance and varietal deployment strategies essential for effective disease management
Cancer stem cell, chromosomal instability, and cancer immunity
Cancer stem cells (CSCs) are a unique population of tumor cells with stem cell-like properties. They are believed to be involved in drug resistance, potential therapy failure, tumor relapse after treatment, and ultimately reduced overall survival of cancer patients. One of the causal factors that may lead to CSC formation is chromosomal instability (CIN), a dynamic event leading to numerical and structural changes in the chromosomes. The CIN is also proposed to aid the maintenance of CSCs, contribute towards their heterogeneity, and facilitate their immune escape. However, the role of CIN in the modulation of the immune system in tumors remains contradictory. Studies have revealed that it can lead to both activation and suppression of the immune system. Previous literature suggests that the CIN, CSCs, and cancer immunity (3Cs), interact with and complement each other to create a pro-tumor environment. However, the mechanisms underlying such an interaction are poorly understood. So, in this review article, an attempt has been made to understand the nature of the interaction between the triad of CIN, CSC, and the immune response in tumors and some of the pathways governing the same. Understanding the above may be a positive step towards the complete cure for malignant diseases
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