Supersymmetry enhancement by monopole operators

We describe a method which allows one to study hidden symmetries in a large class of strongly coupled supersymmetric gauge theories in three dimensions. We apply this method to the ABJM theory and to the infrared limit of N=4 SQCD with adjoint and fundamental matter. We show that the U(N) ABJM model with Chern-Simons level k=1 or k=2 has hidden N=8 supersymmetry. Hidden supersymmetry is also shown to occur in N=4 d=3 SQCD with one fundamental and one adjoint hypermultiplet. The latter theory, as well as the U(N) ABJM theory at k=1, are shown to have a decoupled free sector. This provides evidence that both models are dual to the infrared limit of N=8 U(N) super-Yang-Mills theory.Comment: 29 pages, late

Instanton operators in five-dimensional gauge theories

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are creditedN.L. is supported in part by STFC grant ST/J002798/1. C.P. is a Royal Society Research Fellow.N.L. is supported in part by STFC grant ST/J002798/1. C.P. is a Royal Society Research Fellow.N.L. is supported in part by STFC grant ST/J002798/1. OPen Aceess funded by SCOAP

A two-domain elevator mechanism for sodium/proton antiport

Sodium/proton (Na+/H+) antiporters, located at the plasma membrane in every cell, are vital for cell homeostasis1. In humans, their dysfunction has been linked to diseases, such as hypertension, heart failure and epilepsy, and they are well-established drug targets2. The best understood model system for Na+/H+ antiport is NhaA from Escherichia coli1, 3, for which both electron microscopy and crystal structures are available4, 5, 6. NhaA is made up of two distinct domains: a core domain and a dimerization domain. In the NhaA crystal structure a cavity is located between the two domains, providing access to the ion-binding site from the inward-facing surface of the protein1, 4. Like many Na+/H+ antiporters, the activity of NhaA is regulated by pH, only becoming active above pH 6.5, at which point a conformational change is thought to occur7. The only reported NhaA crystal structure so far is of the low pH inactivated form4. Here we describe the active-state structure of a Na+/H+ antiporter, NapA from Thermus thermophilus, at 3 Å resolution, solved from crystals grown at pH 7.8. In the NapA structure, the core and dimerization domains are in different positions to those seen in NhaA, and a negatively charged cavity has now opened to the outside. The extracellular cavity allows access to a strictly conserved aspartate residue thought to coordinate ion binding1, 8, 9 directly, a role supported here by molecular dynamics simulations. To alternate access to this ion-binding site, however, requires a surprisingly large rotation of the core domain, some 20° against the dimerization interface. We conclude that despite their fast transport rates of up to 1,500 ions per second3, Na+/H+ antiporters operate by a two-domain rocking bundle model, revealing themes relevant to secondary-active transporters in general

Refined Checks and Exact Dualities in Three Dimensions

We discuss and provide nontrivial evidence for a large class of dualities in three-dimensional field theories with different gauge groups. We match the full partition functions of the dual phases for any value of the couplings to underpin our proposals. We focus on two classes of models. The first class, motivated by the AdS/CFT conjecture, consists of necklace U(N) quiver gauge theories with non chiral matter fields. We also consider orientifold projections and establish dualities among necklace quivers with alternating orthogonal and symplectic groups. The second class consists of theories with tensor matter fields with free theory duals. In most of these cases the R-symmetry mixes with IR accidental symmetries and we develop the prescription to include their contribution into the partition function and the extremization problem accordingly.Comment: 38 pages, 3 figure, using jheppu

Maternal angiotensinogen (AGT) haplotypes, fetal renin (REN) haplotypes and risk of preeclampsia; estimation of gene-gene interaction from family-triad data

Background Preeclampsia is a debilitating disorder affecting approximately 3% of pregnant women in the Western world. Although inconclusive, current evidence suggests that the renin-angiotensin system may be involved in hypertension. Therefore, our objective was to determine whether the genes for placental renin (REN) and maternal angiotensinogen (AGT) interact to influence the risk of preeclampsia. Methods Three haplotype-tagging SNPs (htSNPs) covering REN (rs5705, rs1464818, and rs3795575) and another three covering AGT (rs2148582, rs2478545 and rs943580) were genotyped in 99 mother-father-child triads of preeclampsia pregnancies. We estimated relative risks (RR) conferred by maternal AGT and fetal REN haplotypes using HAPLIN, a statistical software designed to detect multi-marker transmission distortion among triads. To assess a combined effect of maternal AGT and fetal REN haplotypes, the preeclamptic triads were first stratified by presence/absence of maternal AGT haplotype C-T-A and tested for an effect of fetal REN across these strata. Results We found evidence that mothers carrying the most frequent AGT haplotype, C-T-A, had a reduced risk of preeclampsia (RR of 0.4, 95% CI = 0.2-0.8 for heterozygotes and 0.6, 95% CI = 0.2-1.5 for homozygotes). Mothers homozygous for AGT haplotypes t-c-g and C-c-g appeared to have a higher risk, but only the former was statistically significant. We found only weak evidence of an overall effect of fetal REN haplotypes and no support for our hypothesis that an effect of REN depended on whether the mother carried the C-T-A haplotype of AGT (p = 0.33). Conclusion Our findings indicate that the mother's AGT haplotypes affect her risk for developing preeclampsia. However, this risk is not influenced by fetal REN haplotypes.publishedVersio

Indian Ocean Dipole drives malaria resurgence in East African highlands

Malaria resurgence in African highlands in the 1990s has raised questions about the underlying drivers of the increase in disease incidence including the role of El-Niño-Southern Oscillation (ENSO). However, climatic anomalies other than the ENSO are clearly associated with malaria outbreaks in the highlands. Here we show that the Indian Ocean Dipole (IOD), a coupled ocean-atmosphere interaction in the Indian Ocean, affected highland malaria re-emergence. Using cross-wavelet coherence analysis, we found four-year long coherent cycles between the malaria time series and the dipole mode index (DMI) in the 1990s in three highland localities. Conversely, we found a less pronounced coherence between malaria and DMI in lowland localities. The highland/lowland contrast can be explained by the effects of mesoscale systems generated by Lake Victoria on its climate basin. Our results support the need to consider IOD as a driving force in the resurgence of malaria in the East African highlands

Aspects of superconformal multiplets in D > 4

SCOAP

Optimizing Taq Polymerase Concentration for Improved Signal-to-Noise in the Broad Range Detection of Low Abundance Bacteria

BACKGROUND:PCR in principle can detect a single target molecule in a reaction mixture. Contaminating bacterial DNA in reagents creates a practical limit on the use of PCR to detect dilute bacterial DNA in environmental or public health samples. The most pernicious source of contamination is microbial DNA in DNA polymerase preparations. Importantly, all commercial Taq polymerase preparations inevitably contain contaminating microbial DNA. Removal of DNA from an enzyme preparation is problematical. METHODOLOGY/PRINCIPAL FINDINGS:This report demonstrates that the background of contaminating DNA detected by quantitative PCR with broad host range primers can be decreased greater than 10-fold through the simple expedient of Taq enzyme dilution, without altering detection of target microbes in samples. The general method is: For any thermostable polymerase used for high-sensitivity detection, do a dilution series of the polymerase crossed with a dilution series of DNA or bacteria that work well with the test primers. For further work use the concentration of polymerase that gave the least signal in its negative control (H(2)O) while also not changing the threshold cycle for dilutions of spiked DNA or bacteria compared to higher concentrations of Taq polymerase. CONCLUSIONS/SIGNIFICANCE:It is clear from the studies shown in this report that a straightforward procedure of optimizing the Taq polymerase concentration achieved "treatment-free" attenuation of interference by contaminating bacterial DNA in Taq polymerase preparations. This procedure should facilitate detection and quantification with broad host range primers of a small number of bona fide bacteria (as few as one) in a sample

Vascular endothelial growth factor as a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD

BACKGROUND: Several studies have indicated that one of the most potent mediators involved in pulmonary vascular remodeling is vascular endothelial growth factor (VEGF). This study was designed to determine whether airway VEGF level reflects pulmonary vascular remodeling in patients with bronchitis-type of COPD. METHODS: VEGF levels in induced sputum were examined in 23 control subjects (12 non-smokers and 11 ex-smokers) and 29 patients with bronchitis-type of COPD. All bronchitis-type patients performed exercise testing with right heart catheterization. RESULTS: The mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) after exercise were markedly increased in all bronchitis-type patients. However, both parameters after exercise with breathing of oxygen was significantly lower than in those with breathing of room air. To attenuate the effect of hypoxia-induced pulmonary vasoconstriction during exercise, we used the change in mPAP or PVR during exercise with breathing of oxygen as a parameter of pulmonary vascular remodeling. Change in mPAP was significantly correlated with VEGF level in induced sputum from patients with chronic bronchitis (r = 0.73, p = 0.0001). Moreover, change in PVR was also correlated with VEGF level in those patients (r = 0.57, p = 0.003). CONCLUSION: A close correlation between magnitude of pulmonary hypertension with exercise and VEGF level in bronchitis-type patients could be observed. Therefore, these findings suggest the possibility that VEGF level in induced sputum is a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD