Duality of privacy amplification against quantum adversaries and data compression with quantum side information

We show that the tasks of privacy amplification against quantum adversaries and data compression with quantum side information are dual in the sense that the ability to perform one implies the ability to perform the other. These are two of the most important primitives in classical information theory, and are shown to be connected by complementarity and the uncertainty principle in the quantum setting. Applications include a new uncertainty principle formulated in terms of smooth min- and max-entropies, as well as new conditions for approximate quantum error correction.Comment: v2: Includes a derivation of an entropic uncertainty principle for smooth min- and max-entropies. Discussion of the Holevo-Schumacher-Westmoreland theorem remove

Psychosocial factors influencing planning for retirement : a quantitative analysis : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University, Palmerston North, New Zealand

A population approaching the end of their working life might reasonably be expected to be actively engaged in planning their retirement. This research investigates that assumption in a New Zealand population aged 55 through 70 who are currently in the work force and within ten years of being eligible for the New Zealand pension. The social and psychological factors impacting retirement planning, as determined by an examination of the literature, were identified as health and wealth. Distal to these two factors are the ramifications of income, selected occupation and career, educational choices and investment in dependents and family. Survey results from a representative sample of this population were analysed using Structural Equation Modelling to assess whether these expected planning behaviours were relevant in New Zealanders. Two equivalent models utilised the survey questions in different combinations to gain an understanding of the impact of these psychosocial determinants. The results demonstrate how all these factors impact differently on women and men but that, contrary to expectation, health does not correlate with retirement planning. The implications of these results are discussed

Status of Average-x from Lattice QCD

As algorithms and computing power have advanced, lattice QCD has become a precision technique for many QCD observables. However, the calculation of nucleon matrix elements remains an open challenge. I summarize the status of the lattice effort by examining one observable that has come to represent this challenge, average-x: the fraction of the nucleon's momentum carried by its quark constituents. Recent results confirm a long standing tendency to overshoot the experimentally measured value. Understanding this puzzle is essential to not only the lattice calculation of nucleon properties but also the broader effort to determine hadron structure from QCD.Comment: proceedings for 3rd International Workshop on Nucleon Structure at Large Bjorken

Plant dispersal across the tropical Atlantic by wind and sea currents

This review brings together evidence on the monophyly and ages of angiosperm lineages ranging across the tropical Atlantic with data on the direction, strength, and speed of sea currents and wind jets across that ocean. Mainly for pragmatic reasons (data availability), the focus is on genera, which introduces a rank-based constraint into the analysis. However, trans-Atlantic disjunctions at the genus level seemed more likely to be attributable to long-distance dispersal than those involving families or species; family-level disjunctions often may date back to the breakup of Africa and South America, and species-level disjunctions often may be anthropogenic. At least 110 genera (listed in this article) contain species on both sides of the tropical Atlantic. Molecular phylogenies and age estimates from molecular clocks are available for 11 disjunct genera, tribes, and species. Inferred directions and modes of dispersal can be related parsimoniously to water currents between Africa and South America and to exceptional westerly winds blowing from northeastern Brazil to northwest Africa. Based on diaspore morphology and inferred dispersal biology in the 110 genera, trans-Atlantic dispersal by water (in both directions) appears more common than dispersal by wind or on birds. Wind dispersal appears to have occurred in the direction from South America to West Africa but rarely in the opposite direction

Circumscription and phylogeny of the Laurales

The order Laurales comprises a few indisputed core constituents, namely Gomortegaceae, Hernandiaceae, Lauraceae, and Monimiaceae sensu lato, and an equal number of families that have recently been included in, or excluded from, the order, namely Amborellaceae, Calycanthaceae, Chloranthaceae, Idiospermaceae, and Trimeniaceae. In addition, the circumscription of the second largest family in the order, the Monimiaceae, has been problematic. I conducted two analyses, one on 82 rbcL sequences representing all putative Laurales and major lineages of basal angiosperms to clarify the composition of the order and to determine the relationships of the controversal families, and the other on a concatenated matrix of sequences from 28 taxa and six plastid genome regions (rbcL, rpl16, trnT-trnL, trnL-trnF, atpB-rbcL, and psbA-trnH) that together yielded 898 parsimony-informative characters. Fifteen morphological characters that play a key role in the evolution and classification of Laurales were analyzed on the most parsimonious molecular trees as well as being included directly in the analysis in a total evidence approach. The resulting trees strongly support the monophyly of the core Laurales (as listed above) plus Calycanthaceae and Idiospermaceae. Trimeniaceae form a clade with Illiciaceae, Schisandraceae, and Austrobaileyaceae, whereas Amborellaceae and Chloranthaceae represent isolated clades that cannot be placed securely based on rbcL alone. Within Laurales, the deepest split is between Calycanthaceae (including Idiospermaceae) and the remaining six families, which in turn form two clades, the Siparunaceae (Atherospermataceae-Gomortegaceae) and the Hernandiaceae (Monimiaceae s.str. [sensu stricto]-Lauraceae). Monimiaceae clearly are polyphyletic as long as they include Atherospermataceae and Siparunaceae. Several morphological character state changes are congruent with the molecular tree: (1) Calycanthaceae have disulculate tectate-columellate pollen, while their sister clade has inaperturate thin-exined pollen, with the exception of Atherospermataceae, which have columellate but meridionosulcate or disulcate pollen. (2) Calycanthaceae have two ventral ovules while their sister clade has solitary ovules. Within this sister clade, the Hernandiaceae (Lauraceae-Monimiaceae) have apical ovules, while the Siparunaceae (Atherospermataceae-Gomortegaceae) are inferred to ancestrally have basal ovules, a condition lost in Gomortega, the only lauralean genus with a syncarpous ovary. (3) Calycanthaceae lack floral nectaries (except for isolated nectarogeneous fields on the inner tepals), while their sister clade ancestrally has paired nectar glands on the filaments. Filament glands were independently lost in higher Monimiaceae and in Siparunaceae concomitant with pollinator changes away from nectar-foraging flies and bees to non-nectar feeding beetles and gall midges. (4) Disporangiate stamens with anthers dehiscing by two apically hinged valves are ancestral in Siparunaceae-(Atherospermataceae- Gomortegaceae) and evolved independently within Hernandiaceae and Lauraceae. Depending on the correct placement of Calycanthaceae-like fossil flowers, tetrasporangiate anthers with valvate dehiscence (with the valves laterally hinged) may be ancestral in Laurales and lost in modern Calycanthaceae and Monimiaceae