Analysis of Shot Noise at Finite Temperatures in Fractional Quantum Hall Edge States

We investigate shot noise at {\it finite temperatures} induced by the quasi-particle tunneling between fractional quantum Hall (FQH) edge states. The resulting Fano factor has the peak structure at a certain bias voltage. Such a structure indicates that quasi-particles are weakly {\it glued} due to thermal fluctuation. We show that the effect makes it possible to probe the difference of statistics between $\nu=1/5,{}2/5$ FQH states where quasi-particles have the same unit charge.Finally we propose a way to indirectly obtain statistical angle in hierarchical FQH states.Comment: 5 pages, 3 figure

Quasi-Particle Tunneling in Anti-Pfaffian Quantum Hall State

We study tunneling phenomena at the edge of the anti-Pfaffian quantum Hall state at the filling factor $\nu=5/2$. The edge current in a single point-contact is considered. We focus on nonlinear behavior of two-terminal conductance with the increase in negative split-gate voltage. Expecting the appearance of the intermediate conductance plateau we calculate the value of its conductance by using the renormalization group (RG) analysis. Further, we show that non-perturbative quasi-particle tunneling is effectively described as perturbative electron tunneling by the instanton method. The two-terminals conductance is written as a function of the gate voltage. The obtained results enable us to distinguish the anti-Pfaffian state from the Pfaffian state experimentally.Comment: 5 pages, 4 figure

Vitamin D pathway-related gene polymorphisms and their association with metabolic diseases: a literature review

Purpose: Given that the relationship between vitamin D status and metabolic diseases such as obesity and type 2 diabetes (T2D) remains unclear, this review will focus on the genetic associations, which are less prone to confounding, between vitamin D-related single nucleotide polymorphisms (SNPs) and metabolic diseases. Methods: A literature search of relevant articles was performed on PubMed up to December 2019. Those articles that had examined the association of vitamin D-related SNPs with obesity and/or T2D were included. Two reviewers independently evaluated the eligibility for the inclusion criteria and extracted the data. In total, 73 articles were included in this review. Results: There is a lack of research focussing on the association of vitamin D synthesis-related genes with obesity and T2D; however, the limited available research, although inconsistent, is suggestive of a protective effect on T2D risk. While there are several studies that investigated the vitamin D metabolism-related SNPs, the research focussing on vitamin D activation, catabolism and transport genes is limited. Studies on CYP27B1, CYP24A1 and GC genes demonstrated a lack of association with obesity and T2D in Europeans; however, significant associations with T2D were found in South Asians. VDR gene SNPs have been extensively researched; in particular, the focus has been mainly on BsmI (rs1544410), TaqI (rs731236), ApaI (rs7975232) and FokI (rs2228570) SNPs. Even though the association between VDR SNPs and metabolic diseases remain inconsistent, some positive associations showing potential effects on obesity and T2D in specific ethnic groups were identified. Conclusion: Overall, this literature review suggests that ethnic-specific genetic associations are involved. Further research utilizing large studies is necessary to better understand these ethnic-specific genetic associations between vitamin D deficiency and metabolic diseases

Follow the Networks

On February 27, 1994, three Costa Rican engineers took an afternoon flight from San José to Managua, Nicaragua. The timing for this trip was good in more ways than one. Little by little, more than a decade of war in the region was coming to an end. The trip had a single purpose: participate in Nicaragua’s connection to the Internet. In Managua, a group of collaborators who had worked for months to establish this link awaited them. For almost three years, they had been making plans together for Nicaragua’s Internet connection through Costa Rica via an analog microwave link built in the late 60s, a decade in which the concept of Central American integration had flourished. From Costa Rica, Nicaragua would be connected to Homestead, Florida through a satellite antenna. This goal was achieved the very next day and was celebrated enthusiastically. A public event was held at the Nicaraguan university that led this initiative. After a series of training and work sessions with their Nicaraguan counterparts, the Costa Rican engineers returned to San José on March 2. Only four months later, they would repeat this process in a different setting: the new site was Panama, but the purpose and procedures were almost identical.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro de Investigación en Comunicación (CICOM