Majorana Physics Through the Cabibbo Haze

We present a model in which the Supersymmetric Standard Model is augmented by the family symmetry \bs{\m Z_7 \rtimes \m Z_3}. Motivated by $SO(10)$, where the charge two-thirds and neutral Dirac Yukawa matrices are related, we propose, using family symmetry, a special form for the seesaw Majorana matrix; it contains a squared correlated hierarchy, allowing it to mitigate the severe hierarchy of the quark sector. It is reproduced naturally by the invariant operators of \bs{\m Z_7 \rtimes \m Z_3}, with the hierarchy carried by familon fields. In addition to relating the hierarchy of the $\Delta I_{\rm w}=1/2$ to the $\Delta I_{\rm w}=0$ sector, it contains a Gatto-Sartori-Tonin like relation, predicts a normal hierarchy for Tri-bimaximal and Golden Ratio mixings, and gives specific values for the light neutrino masses.Comment: 33 pages, 1 figure. This revised version omits a section where a particular linear combination of dimension-five operators was mistakenly claimed to produce the special form of the Majorana matrix. The main changes are to the Introduction, Sec. 5.1 of the previous version, and Summary and Conclusions. In addition to minor changes throughout, we have corrected an erroneous sign in Eq. 1

Density, structure and dynamics of water: the effect of Van der Waals interactions

It is known that ab initio molecular dynamics (AIMD) simulations of liquid water, based on the generalized gradient approximation (GGA) to density functional theory (DFT), yield structural and diffusive properties in reasonable agreement with experiment only if artificially high temperatures are used in the simulations. The equilibrium density, at normal conditions, of DFT water has been recently shown by Schmidt et al. [J. Phys. chem. B, 113, 11959 (2009)] to be underestimated by different GGA functionals for exchange and correlation, and corrected by the addition of interatomic pair potentials to describe van derWaals (vdW) interactions. In this contribution we present a DFTAIMD study of liquid water using several GGA functionals as well as the van der Waals density functional (vdW-DF) of Dion et al. [Phys. Rev. Lett. 92, 246401(2004)]. As expected, we find that the density of water is grossly underestimated by GGA functionals. When a vdW-DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections. We analyze the origin of the density differences between all the functionals. We show that the vdW-DF increases the population of non-H-bonded interstitial sites, at distances between the first and second coordination shells. However, it excessively weakens the H-bond network, collapsing the second coordination shell. This structural problem is partially associated to the choice of GGA exchange in the vdW-DF. We show that a different choice for the exchange functional is enough to achieve an overall improvement both in structure and diffusivity.Comment: 11 pages, 9 figures, submitted. Revised versio

Long-term calorie restriction in humans is not associated with indices of delayed immunologic aging: A descriptive study.

BACKGROUND: Delayed immunologic aging is purported to be a major mechanism through which calorie restriction (CR) exerts its anti-aging effects in non-human species. However, in non-obese humans, the effect of CR on the immune system has been understudied relative to its effects on the cardiometabolic system. OBJECTIVE: To examine whether CR is associated with delayed immunologic aging in non-obese humans. METHODS: We tested whether long-term CR practitioners (average 10.03 years of CR) evidenced decreased expression of T cell immunosenescence markers and longer immune cell telomeres compared to gender-, race/ethnicity-, age-, and education-matched "healthy" Body Mass Index (BMI) and "overweight"/"obese" BMI groups. RESULTS: Long-term human CR practitioners had lower BMI (p <  0.001) and fasting glucose (p <  0.001), as expected. They showed similar frequencies of pre-senescent cells (CD8+CD28- T cells and CD57 and PD-1 expressing T cells) to the comparison groups. Even after adjusting for covariates, including cytomegalovirus status, we observed shorter peripheral blood mononuclear cell telomeres in the CR group (p = 0.012) and no difference in granulocyte telomeres between groups (p = 0.42). CONCLUSIONS: We observed no clear evidence that CR as it is currently practiced in humans delays immune aging related to telomere length or T cell immunosenescent markers

Social impact technology dissemination in rural southern India

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.CD-ROM contains PDF of thesis.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 84-89).Despite their growing popularity, bottom-up, innovation-based development efforts are failing to make a significant social impact at the Bottom of the Pyramid (BOP). Merely inventing widgets for development - like affordable solar lanterns, improved cookstoves, and bicycle-powered machines - is not enough. They must move from the lab to the land, into the hands of the people they are intended to benefit. Innovations in scalable, sustainable models for social impact technology dissemination are desperately needed, lest these technologies be designed in vain. In this thesis, I first discuss previous failures in social impact technology dissemination, beginning with the Appropriate Technology movement and continuing with the efforts of multinational corporations that have tried selling into the BOP. Through field research in southern India, I then analyze the current efforts and experiments of small and medium enterprises. Although there are pockets of relative success in the field, there is no truly outstanding scalable and financially sustainable model for dissemination. There are multiple reasons for this, including the expenses taken on by manufacturers when they attempt to establish and operate their own distribution channels and the lack of technology aggregation, which has the potential to lower dissemination costs. Finally, I describe my experiences co-founding Essmart, a rural distributor of social impact technologies. This effort is based directly on my field research. Essmart's goals are to bridge the gap between global manufacturers of social impact technologies and rural end users. The venture gives rural retail stores access to technologies that improve their customers' lives. Through months of reflective practice, I have come to recognize the importance of building mutually beneficial and mutually dependent relationships with BOP stakeholders. This is one of the most important ways to create and ensure social impact at the Bottom of the Pyramid through innovation.by Diana M. Jue.M.C.P

Consensus of self-driven agents with avoidance of collisions

In recent years, many efforts have been addressed on collision avoidance of collectively moving agents. In this paper, we propose a modified version of the Vicsek model with adaptive speed, which can guarantee the absence of collisions. However, this strategy leads to an aggregated state with slowly moving agents. We therefore further introduce a certain repulsion, which results in both faster consensus and longer safe distance among agents, and thus provides a powerful mechanism for collective motions in biological and technological multi-agent systems.Comment: 8 figures, and 7 page

Alcohol consumption and leukocyte telomere length.

The relationship between alcohol consumption and mortality generally exhibits a U-shaped curve. The longevity observed with moderate alcohol consumption may be explained by other confounding factors, and, if such a relationship is present, the mechanism is not well understood. Indeed, the optimal amount of alcohol consumption for health has yet to be determined. Leukocyte telomere length is an emerging quantifiable marker of biological age and health, and a shorter telomere length is a predictor of increased mortality. Because leukocyte telomere length is a quantifiable and objectively measurable biomarker of aging, we sought to identify the amount of alcohol consumption associated with the longest telomere length and least telomere length attrition. Among over 2,000 participants from two distinct cohort studies, we found no pattern of alcohol consumption that was associated with longer telomere length or less telomere length attrition over time. Binge drinking may reduce telomere length. Using telomere length as a marker of age and health, these data fail to demonstrate any benefits of alcohol consumption, even when consumed in moderation

Quantum delayed-choice experiment with a beam splitter in a quantum superposition

A quantum system can behave as a wave or as a particle, depending on the experimental arrangement. When for example measuring a photon using a Mach-Zehnder interferometer, the photon acts as a wave if the second beam-splitter is inserted, but as a particle if this beam-splitter is omitted. The decision of whether or not to insert this beam-splitter can be made after the photon has entered the interferometer, as in Wheeler's famous delayed-choice thought experiment. In recent quantum versions of this experiment, this decision is controlled by a quantum ancilla, while the beam splitter is itself still a classical object. Here we propose and realize a variant of the quantum delayed-choice experiment. We configure a superconducting quantum circuit as a Ramsey interferometer, where the element that acts as the first beam-splitter can be put in a quantum superposition of its active and inactive states, as verified by the negative values of its Wigner function. We show that this enables the wave and particle aspects of the system to be observed with a single setup, without involving an ancilla that is not itself a part of the interferometer. We also study the transition of this quantum beam-splitter from a quantum to a classical object due to decoherence, as observed by monitoring the interferometer output.Comment: 9 pages, 7 figures, Accepted by Physical Review Letter