Quasideterministic generation of maximally entangled states of two mesoscopic atomic ensembles by adiabatic quantum feedback

We introduce an efficient, quasideterministic scheme to generate maximally entangled states of two atomic ensembles. The scheme is based on quantum nondemolition measurements of total atomic populations and on adiabatic quantum feedback conditioned by the measurements outputs. The high efficiency of the scheme is tested and confirmed numerically for ideal photodetection as well as in the presence of losses.Comment: 7 pages, 6 figures, title changed, revised version published on Phys. Rev

A surge of late-occurring meiotic double-strand breaks rescues synapsis abnormalities in spermatocytes of mice with hypomorphic expression of SPO11

Meiosis is the biological process that, after a cycle of DNA replication, halves the cellular chromosome complement, leading to the formation of haploid gametes. Haploidization is achieved via two successive rounds of chromosome segregation, meiosis I and II. In mammals, during prophase of meiosis I, homologous chromosomes align and synapse through a recombination-mediated mechanism initiated by the introduction of DNA double-strand breaks (DSBs) by the SPO11 protein. In male mice, if SPO11 expression and DSB number are reduced below heterozygosity levels, chromosome synapsis is delayed, chromosome tangles form at pachynema, and defective cells are eliminated by apoptosis at epithelial stage IV at a spermatogenesis-specific endpoint. Whether DSB levels produced in Spo11 +/− spermatocytes represent, or approximate, the threshold level required to guarantee successful homologous chromosome pairing is unknown. Using a mouse model that expresses Spo11 from a bacterial artificial chromosome, within a Spo11 −/− background, we demonstrate that when SPO11 expression is reduced and DSBs at zygonema are decreased (approximately 40 % below wild-type level), meiotic chromosome pairing is normal. Conversely, DMC1 foci number is increased at pachynema, suggesting that under these experimental conditions, DSBs are likely made with delayed kinetics at zygonema. In addition, we provide evidences that when zygotene-like cells receive enough DSBs before chromosome tangles develop, chromosome synapsis can be completed in most cells, preventing their apoptotic elimination

La globalització i els seus efectes sobre la nostra relació amb el territori

La globalització ha normalitzat un model de vida allunyat de la dimensió local, fet que ha generat un desarrelament de la nostra identitat social de la realitat dels territoris. La promoció de nous espais del coneixement, juntament amb dinàmiques d’intel·ligència col·lectiva situada, fa emergir una inversió de tendència

Turbulence suppression by energetic particle effects in modern optimized stellarators

Turbulent transport is known to limit the plasma confinement of present-day optimized stellarators. To address this issue, a novel method to strongly suppress turbulence in such devices is proposed, namely the resonant wave-particle interaction of supra-thermal particles - e.g., from ion-cyclotron-resonance-frequency (ICRF) heating - with turbulence-driving microinstabilities like ion-temperature-gradient (ITG) modes. The effectiveness of this mechanism is demonstrated via analytic theory and large-scale gyrokinetic simulations, revealing an overall turbulence reduction by up to $80\%$. These results hold the promise of new and still unexplored stellarator scenarios with enhanced confinement and improved performance, essential for achieving burning plasmas in future devices

Redeveloping Fair Park as a catalyst for the revitalization of South Dallas

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning; and, (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 81-83).This thesis studies Fair Park, a 277 acre public park located in Dallas, Texas. Fair Park represents prevalent planning challenges - the repurposing of sites that have outlived their initial uses and the reintegration of such sites into their surrounding contexts. To better understand the site, a historical overview of the development of Fair Park from inception to its current condition is provided. Fair Park is looked at within the context of South Dallas in efforts to understand the past planning efforts and why they have succeeded/failed. A new framework for thinking about future planning efforts for Fair Park is proposed so that the site can catalyze the revitalization of South Dallas at large. Two alternative land use scenarios are provided to illustrate the site's development potential under the proposed framework. The thesis concludes with proposing a structure for moving forward with the planning and implementation of new development in Fair Park and summarizes some potential obstacles to implementation that must be carefully considered.by Giuliana Siena Di Mambro.M.B.A.M.C.P

Pore Space Topology Controls Ultrasonic Waveforms in Dry Volcanic Rocks

Pore space controls the mechanical and transport properties of rocks. At the laboratory scale, seismic modeling is usually performed in relatively homogeneous settings, and the influence of the pore space on the recorded wavefields is determined by rock-fluid interactions. Understanding this influence in dry rocks is instrumental for assessing the impact of pore topology on waves propagating in heterogeneous environments, such as volcanoes. Here, we simulated the propagation of shear waves as a function of pore space parameters in computational models built as proxies for volcanic rocks. The spectral-element simulations provide results comparable with ultrasonic experiments, and the outcome shows that the size, shape, volume, and location of pores impact amplitudes and phases. These variations intensify in waveform coda after multiple scattering. Our results confirm that pore topology is one of the primary regulators of the propagation of elastic waves in dry rocks regardless of porosity

Klippel-Feil syndrome. When using fiberoptic bronchoscopy guide, a case report

Klippel-Feil syndrome is a rare disease with congenital musculoskeletal condition characterized by faulty segmentation of cervical vertebrae and consists of cervical vertebra fusions with limitation of head movements, short neck and low posterior hairline. In several cases the syndrome is associated with cardiovascular malformations. Patients affected by Klippel-Feil syndrome could be an anesthetic challenge, not only during cardiac surgery. We are presenting a case of Klippel-Feil Syndrome in an adult patient, who was operated on for a pulmonary valve insufficiency in a previously corrected Tetralogy of Fallot Syndrome. We are going to discuss the features of this rare syndrome