357 research outputs found
The complete set of infinite volume ground states for Kitaev's abelian quantum double models
We study the set of infinite volume ground states of Kitaev's quantum double
model on for an arbitrary finite abelian group . It is known
that these models have a unique frustration-free ground state. Here we drop the
requirement of frustration freeness, and classify the full set of ground
states. We show that the ground state space decomposes into different
charged sectors, corresponding to the different types of abelian anyons (also
known as superselection sectors). In particular, all pure ground states are
equivalent to ground states that can be interpreted as describing a single
excitation. Our proof proceeds by showing that each ground state can be
obtained as the weak limit of finite volume ground states of the quantum
double model with suitable boundary terms. The boundary terms allow for states
which represent a pair of excitations, with one excitation in the bulk and one
pinned to the boundary, to be included in the ground state space.Comment: 27 pages, 6 figures. v2: minor corrections, some simplifications and
clarificactions adde
Nonlinear dynamic behaviour of vertical and horizontal rotors in compliant liner tilting pad journal bearings: Some design considerations
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Emotional Intelligence is a Protective Factor for Suicidal Behavior
Objective: Little is known about what factors protect against the occurrence of suicide ideation and attempts. We tested whether emotional intelligence (EI)—the ability to perceive, integrate, understand, and manage one’s emotions—decreases the likelihood of suicide ideation and attempts among those at risk. Method: Adolescents (N=54) aged 12-19 were recruited from local psychiatric clinics and the community to participate in this cross-sectional laboratory-based study. Analyses examined whether the relations between childhood sexual abuse (CSA) and suicide ideation and attempts were moderated by adolescents’ EI. These constructs were assessed using self-report, structured interviews, and performance-based tests, respectively. Results: Analyses revealed that EI is a protective factor for both suicide ideation and attempts. Specifically, CSA was strongly predictive of these outcomes among those with low EI, weakly predictive among those with medium EI, and completely unrelated among those with high EI. Follow-up analyses revealed that the protective effect of EI was driven primarily by differences in Strategic EI (i.e., ability to understand and manage emotions) but not Experiential EI (i.e., ability to perceive emotions and integrate emotions into thoughts). Conclusions: This study provides preliminary evidence that EI is a protective factor for suicide ideation and attempts. Important next steps include testing the moderating influence of EI on a wider range of stressful life events and self-injurious behaviors, as well as conducting experimental studies to determine whether enhancing EI decreases the subsequent occurrence of these behavior problems.Psycholog
On the stability of charges in infinite quantum spin systems
We consider a theory of superselection sectors for infinite quantum spin
systems, describing charges that can be approximately localized in cone-like
regions. The primary examples we have in mind are the anyons (or charges) in
topologically ordered models such as Kitaev's quantum double models and
perturbations of such models. In order to cover the case of perturbed quantum
double models, the Doplicher-Haag-Roberts approach, in which strict
localization is assumed, has to be amended. To this end we consider
endomorphisms of the observable algebra that are almost localized in cones.
Under natural conditions on the reference ground state (which plays a role
analogous to the vacuum state in relativistic theories), we obtain a braided
tensor -category describing the sectors. We also introduce a
superselection criterion selecting excitations with energy below a threshold.
When the threshold energy falls in a gap of the spectrum of the ground state,
we prove stability of the entire superselection structure under perturbations
that do not close the gap. We apply our results to prove that all essential
properties of the anyons in Kitaev's abelian quantum double models are stable
against perturbations.Comment: v2: 40 pages. Improved presentation, some corrections. v1: 37 pages.
Some results were first reported in the dissertation of MC, arXiv:1708.0503
Response of Invasive Longhorn Beetles (Coleoptera: Lamiinae) to Known Cerambycid Aggregation-Sex Pheromones in the Puna District of Hawaii Island
The Queensland longhorn borer (QLB; Acalolepta aesthetica [Olliff 1890]; Coleoptera: Cerambycidae: Lamiinae: Monochamini) and plumeria long- horn borer (PLB; Lagocheirus obsoletus [Thomson 1778] = Lagocheirus undatus [Voet 1778]; Coleoptera: Cerambycidae: Lamiinae: Acanthocini) are invasive longhorn beetle species that have become established on the island of Hawaii. Both QLB and PLB are polyphagous. Known hosts of QLB include cacao, citrus, kukui, and breadfruit in Hawaii, and QLB are known to attack live, healthy trees. Currently the beetle occurs in the Puna district of the island, but its range is expanding. PLB is a pest of plumeria and other ornamental plants throughout the state of Hawaii and elsewhere. As a first step towards developing a monitoring tool for these invasive beetles, we tested four known aggregation-sex pheromones of cerambycids in this subfamily—monochamol, fuscumol acetate, fuscumol, and geranylacetone—that have proven effective for attracting more than 30 lamiine species in different areas of the world. When tested in panel traps, these compounds individually and in a blend attracted 9 QLB total, which was not significantly different than the 5 QLB captured in solvent control traps. In contrast, traps baited with one of the tested compounds, fuscumol acetate, captured significantly more PLB than solvent blank control traps. We discuss future research directions for developing attractants using chemical ecology approaches to monitor QLB and PLB
Spotlight on 3-K For All: New York Citys 3-K for All Supports Mothers Labor Force Participation
New York City's 3-K for All program was first introduced to a few districts beginning in 2017 and was gradually made available to all districts by 2021. The rollout prioritized the highest-need districts for prekindergarten services. This report focuses on the role of New York City's 3-K in supporting mothers' labor force participation and employment.Using data from the Early Childhood Poverty Tracker, which repeatedly surveyed the same New York City families with young children from 2017 to 2021, the report investigates whether 3-K availability was associated with increased labor force participation and employment among mothers of preschool-age children in New York City
Chemokine Signaling Directs Trunk Lymphatic Network Formation along the Preexisting Blood Vasculature
SummaryThe lymphatic system is crucial for fluid homeostasis, immune responses, and numerous pathological processes. However, the molecular mechanisms responsible for establishing the anatomical form of the lymphatic vascular network remain largely unknown. Here, we show that chemokine signaling provides critical guidance cues directing early trunk lymphatic network assembly and patterning. The chemokine receptors Cxcr4a and Cxcr4b are expressed in lymphatic endothelium, whereas chemokine ligands Cxcl12a and Cxcl12b are expressed in adjacent tissues along which the developing lymphatics align. Loss- and gain-of-function studies in zebrafish demonstrate that chemokine signaling orchestrates the stepwise assembly of the trunk lymphatic network. In addition to providing evidence for a lymphatic vascular guidance mechanism, these results also suggest a molecular basis for the anatomical coalignment of lymphatic and blood vessels
Spotlight on Early Childhood Education: Participation in Pre-K before and during the COVID-19 pandemic
The earliest educational experiences of children's lives are critical for their development and lay the foundation for their future achievement and well-being. For children from families facing socioeconomic disadvantage, high-quality public preschool (typically referred to as pre-K) is particularly important because of its potential to close educational opportunity gaps. Early childhood programs like preschool are also beneficial for parents because they allow parents to work or pursue education, while ensuring that children are well cared for in an enriching environment.Families in New York City are attuned to the importance of early education in large part due to the emphasis that the city has placed on its full-day universal pre-K program, known as Pre-K for All for four-year-old children. Pre-K for All is one of the largest pre-K programs in the country, serving an average of 70,000 children annually (about 65% of all New York City four-year-olds) prior to 2020. The COVID-19 pandemic tremendously disrupted New Yorkers' lives, and early education programs (including pre-K for All programs) faced difficult challenges during the height of the pandemic and in its wake. The Poverty Tracker surveyed families and their participation in Pre-K programs before and during the COVID-19 pandemic
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