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The leakage of quantum information out of the two computational states of a qubit into other energy states represents a major challenge for quantum error correction. During the operation of an error-corrected algorithm, leakage builds over time and spreads through multi-qubit interactions. This leads to correlated errors that degrade the exponential suppression of the logical error with scale, thus challenging the feasibility of quantum error correction as a path towards fault-tolerant quantum computation. Here, we demonstrate a distance-3 surface code and distance-21 bit-flip code on a quantum processor for which leakage is removed from all qubits in each cycle. This shortens the lifetime of leakage and curtails its ability to spread and induce correlated errors. We report a tenfold reduction in the steady-state leakage population of the data qubits encoding the logical state and an average leakage population of less than 1 × 10−3 throughout the entire device. Our leakage removal process efficiently returns the system back to the computational basis. Adding it to a code circuit would prevent leakage from inducing correlated error across cycles. With this demonstration that leakage can be contained, we have resolved a key challenge for practical quantum error correction at scale.Physical realizations of qubits are often vulnerable to leakage errors, where the system ends up outside the basis used to store quantum information. A leakage removal protocol can suppress the impact of leakage on quantum error-correcting codes.

El objetivo de este trabajo investigativo es averiguar sobre la utilización de micro-implantes en tratamientos de ortodoncia, los cuales ayudan a la corrección de las maloclusiones dentales. La utilización de los micro-implantes es una práctica aplicada y recomendada en la actualidad por ortodoncistas, ya que pueden ser removidos con facilidad, luego de realizado el procedimiento. Se realizó una revisión bibliográfica en donde se obtuvo información necesaria sobre la utilización de microimplantes en tratamientos de ortodoncia, concluyéndose que gracias a los micro-implantes se han desarrollado un gran avance en cuanto a los tratamientos de ortodoncia, ya que estos sirven de anclaje para los movimientos ortodónticos, mejorando la estética y nivelando los dientes consiguiendo una buena oclusión dental.

Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte recognized for its genetic variability and high tolerance to salinity. The objective of this study was to evaluate the effect of NaCl on three accessions of quinoa from the Camacani germplasm bank of the National University of the Altiplano, Peru, at three NaCl concentrations (0, 200 and 400 mM) under greenhouse conditions. Four morphological variables (plant height, root length, percentage of root DM, and aerial DM), as well as seven metabolic variables (chlorophyll, proline, phenols, flavonoids, saponins, amino acids and proteins content by spectrophotometric analysis) and electrolyte leakage (EL) in leaves were analyzed. Increasing NaCl exposure was positively correlated with increases in EL, proline, and saponin, while negatively correlated with leaf protein content. In accession PECQ 20037, for example, foliar protein content varied from 18.7% at 0 mM NaCl to 10.57% at 400 mM NaCl. The results indicated that accessions PECQ 20037 and Negra Oruro tolerated the 400 mM NaCl concentration better than Sajama.

Leakage of quantum information out of computational states into higher energy states represents a major challenge in the pursuit of quantum error correction (QEC). In a QEC circuit, leakage builds over time and spreads through multi-qubit interactions. This leads to correlated errors that degrade the exponential suppression of logical error with scale, challenging the feasibility of QEC as a path towards fault-tolerant quantum computation. Here, we demonstrate the execution of a distance-3 surface code and distance-21 bit-flip code on a Sycamore quantum processor where leakage is removed from all qubits in each cycle. This shortens the lifetime of leakage and curtails its ability to spread and induce correlated errors. We report a ten-fold reduction in steady-state leakage population on the data qubits encoding the logical state and an average leakage population of less than \\(1 \\times 10^{-3}\\) throughout the entire device. The leakage removal process itself efficiently returns leakage population back to the computational basis, and adding it to a code circuit prevents leakage from inducing correlated error across cycles, restoring a fundamental assumption of QEC. With this demonstration that leakage can be contained, we resolve a key challenge for practical QEC at scale.

The present research titled “Learning strategies: cognitive-metacognitive for solving arithmetic problems in primary school teachers in public and private educational institutions.” Its objective was to compare the level of knowledge of learning strategies: cognitive and metacognitive for solving arithmetic problems in primary level teachers of public and private educational institutions in Lima 2021, showing the benefits of the application of these strategies in the resolution. of arithmetic problems, as well as the types of arithmetic problems in which we must apply it. The research method is the hypothetical deductive, basic type and with a comparative descriptive design. In the process of measuring the variable, the following instrument was used: questionnaire “Learning strategies: cognitive and metacognitive for problem solving.” The results showed that primary level teachers from public and private Educational Institutions in Lima have a level that tends to have little knowledge of learning strategies: cognitive and metacognitive, on the one hand in public institutions they obtained 42.1% low level , 36.8% very low level and for private institutions with 41.7% very low level, 33.3% low level; With these findings, it is concluded that there is no difference in the level of knowledge of learning strategies: cognitive and metacognitive for solving arithmetic problems in primary level teachers of public and private Educational Institutions in Lima - 2021.

In the United States, public housing is a Federal program intended to provide housing to low-income residents with a highly subsidized rental unit to both alleviate rent burden and stabilize a household. This subsidy enables households to spend their money on basic necessities such as food and transportation. However altruistic, eventually Federal investment in public housing decreased, resulting in dilapidated units, concentrated poverty, violence, and overall disinvestment. Public housing came to symbolize the government’s failure to create successful low-income developments. Specifically, in the city of Los Angeles, the early ground-breaking history of public housing is largely unknown. The city’s public housing agency, the Housing Authority of the City of Los Angeles (HACLA), strove to make housing a human right. HACLA provided housing for the poor, disregarded discriminatory Federal stipulations, and used public housing as a means to integrate races. These ideals were manifested into the Garden Apartments building type—low-density housing built amongst swaths of green communal spaces. These spaces connected residents to the outside, and to their surrounding community. As Los Angeles’ public housing developments pass the seventy-year-old mark, all demonstrate their age. Federal funds for public housing are still dwindling, and HACLA cannot adequately maintain its properties. As a result of this deferred maintenance and lack of investment, HACLA has resorted to “remuddling” or demolishing their public housing. The initial ideals of public housing—to make housing a human right, to uplift families out of poverty, to eliminate racial segregation, and to create communities—underlines the significance of these properties and their role in Los Angeles’ history. By recognizing and harnessing the initial intentions for these developments, and their current role in housing the poor, this thesis argues that heritage conservation has the potential of being a valuable tool in simultaneously uplifting the physical structure of these developments and strengthening community development.

Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the \"arrow of time\" that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time that go beyond established paradigms for characterizing phases, either in or out of equilibrium. On present-day NISQ processors, the experimental realization of this physics is challenging due to noise, hardware limitations, and the stochastic nature of quantum measurement. Here we address each of these experimental challenges and investigate measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping, to avoid mid-circuit measurement and access different manifestations of the underlying phases -- from entanglement scaling to measurement-induced teleportation -- in a unified way. We obtain finite-size signatures of a phase transition with a decoding protocol that correlates the experimental measurement record with classical simulation data. The phases display sharply different sensitivity to noise, which we exploit to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realize measurement-induced physics at scales that are at the limits of current NISQ processors.

Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles. The lack of general solutions for the 3-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multi-particle bound states. In a ring of 24 superconducting qubits, we develop a high fidelity parameterizable fSim gate that we use to implement the periodic quantum circuit of the spin-1/2 XXZ model, an archetypal model of interaction. By placing microwave photons in adjacent qubit sites, we study the propagation of these excitations and observe their bound nature for up to 5 photons. We devise a phase sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the common wisdom that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with \\(\\mathbb{Z}_2\\) parity symmetry. Remarkably, we find that any multi-qubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment.

The purpose of this dissertation research study was to evaluate an adaptation of the Bookmark Method in order to establish new reading growth standards in Guatemala for the early elementary grades. For this Bookmark Method adaptation, data from the longitudinal test results collected by the USAID Lifelong Learning Project in the Western Highlands of Guatemala was used to vertically-link items of three existing NAC (Pruebas Nacionales de Lectura) reading tests of the Ministry of Education of Guatemala for first, second, and third grades. After vertically linking two grade levels of the test scores (first and second; second and third), an Ordered Item Booklet (OIB) was created that contained the items of two adjacent grade-level tests. Immediately afterwards, a standard Bookmark workshop was carried out with selected elementary teachers that used the above-described OIB to establish three new cut scores or growth standards to apply to four new levels of growth in reading. To establish the new growth standards, the cut-off points set by participating teachers during such workshops were applied to student scores in the grade level they were enrolled in for 2016. Such scores corresponded to the ones that had been linked to the previous grade level. Results of the adaptation were evaluated by using different validity sources of information. The first validity source was a correlation of results of the adaptation with a different growth model. Results from applying the adapted Bookmark Method yielded a classification similar to the classification found in the normative model Student Growth Percentile (SGP). The second validity source was to understand the overall experience of teachers in the adapted Bookmark workshop through interviews. Results from interviews showed teachers had a comfortable and engaging experience during the workshop. The third validity source was to estimate agreement between teacher panelists. Agreement among teacher panelists varied widely on the items that represented the standard (implied cut-score).¿ In Guatemala, the Bookmark Method could be use as an alternative to establish growth standards that communicate effectively the standard of growth from one grade to the next in early grades; however, consequential validity of results must be considered.