Tetris is Hard, Even to Approximate

In the popular computer game of Tetris, the player is given a sequence of tetromino pieces and must pack them into a rectangular gameboard initially occupied by a given configuration of filled squares; any completely filled row of the gameboard is cleared and all pieces above it drop by one row. We prove that in the offline version of Tetris, it is NP-complete to maximize the number of cleared rows, maximize the number of tetrises (quadruples of rows simultaneously filled and cleared), minimize the maximum height of an occupied square, or maximize the number of pieces placed before the game ends. We furthermore show the extreme inapproximability of the first and last of these objectives to within a factor of p^(1-epsilon), when given a sequence of p pieces, and the inapproximability of the third objective to within a factor of (2 - epsilon), for any epsilon>0. Our results hold under several variations on the rules of Tetris, including different models of rotation, limitations on player agility, and restricted piece sets.Comment: 56 pages, 11 figure

CoVault: A Secure Analytics Platform

In a secure analytics platform, data sources consent to the exclusive use oftheir data for a pre-defined set of analytics queries performed by a specificgroup of analysts, and for a limited period. If the platform is secure under asufficiently strong threat model, it can provide the missing link to enablingpowerful analytics of sensitive personal data, by alleviating data subjects'concerns about leakage and misuse of data. For instance, many types of powerfulanalytics that benefit public health, mobility, infrastructure, finance, orsustainable energy can be made differentially private, thus alleviatingconcerns about privacy. However, no platform currently exists that issufficiently secure to alleviate concerns about data leakage and misuse; as aresult, many types of analytics that would be in the interest of data subjectsand the public are not done. CoVault uses a new multi-party implementation offunctional encryption (FE) for secure analytics, which relies on a uniquecombination of secret sharing, multi-party secure computation (MPC), anddifferent trusted execution environments (TEEs). CoVault is secure under a verystrong threat model that tolerates compromise and side-channel attacks on anyone of a small set of parties and their TEEs. Despite the cost of MPC, we showthat CoVault scales to very large data sizes using map-reduce based queryparallelization. For example, we show that CoVault can perform queries relevantto epidemic analytics at scale.<br

Controlling TcT_c of Iridium films using interfacial proximity effects

High precision calorimetry using superconducting transition edge sensors requires the use of superconducting films with a suitable $T_c$, depending on the application. To advance high-precision macrocalorimetry, we require low-$T_c$ films that are easy to fabricate. A simple and effective way to suppress $T_c$ of superconducting Iridium through the proximity effect is demonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Au films fabricated by applying heat to the substrate during Ir deposition have been used in the past for superconducting sensors, we present results of $T_c$ suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayers and Ir/Pt bilayers in the range of $\sim$20-100~mK. Measurements of the relative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricated show factor of $\sim$10 higher values in the Ir/Pt case. These new films could play a key role in the development of scalable superconducting transition edge sensors that require low-$T_c$ films to minimize heat capacity and maximize energy resolution, while keeping high-yield fabrication methods.Comment: 5 journal pages, 4 figure

Polyamorous Families – Parenting Practice, Stigma and Social Regulation

As a response to the greater visibility of alternative relationship and family forms, polyamory (i.e. the practice of consensual multi-partner relationships) has recently moved to the centre of public media attention. Questions of polyamory have emerged as a major concern within law, social policy, family sociology, gender and sexuality studies. Yet certain core issues have remained underexplored. This includes the distinctive nature of polyamorous intimacy, the structure of poly household formations and the dynamics of care work within poly families. In particular, poly parenting has been subject to tabooisation and scandalisation. Governing bodies, the judiciary and educational institutions have remained largely ignorant of polyamorous relationships. Research documents the exclusions of poly families (and individuals) from access to legal provisions and protections and their common discrimination in the courts, namely in custody cases. It further highlights the discrimination of polyidentified adolescents in school and college settings and the predicament that poly families face when interacting with public institutions (including schools and kindergardens). Insights into parenting practices and the organisation of childcare is vital for understanding the transformative potential of polyamorous ways of relating. It is also important for challenging the common demonisation and stigmatisation of polyamory within conservative family politics that perceives polyamory exclusively from a harm perspective. This paper will review and critically analyse existing research on poly parenting focussing on three dimensions: (a) parenting practices, (b) social and legal discrimination, and (c) parental response to stigmatisation. The paper argues for a stronger incorporation of queer perspectives within the guiding frameworks of research into parenting in consensually non-monogamous and polyamorous relationships to highlight the transformative potential of the ‘queer bonds’ that sustain many of these practices

Controlling TcT_c of Iridium Films Using the Proximity Effect

A superconducting Transition-Edge Sensor (TES) with low-$T_c$ is essential in a high resolution calorimetric detection. With a motivation of developing sensitive calorimeters for applications in cryogenic neutrinoless double beta decay searches, we have been investigating methods to reduce the $T_c$ of an Ir film down to 20 mK. Utilizing the proximity effect between a superconductor and a normal metal, we found two room temperature fabrication recipes of making Ir-based low-$T_c$ films. In the first approach, an Ir film sandwiched between two Au films, a Au/Ir/Au trilayer, has a tunable $T_c$ in the range of 20-100 mK depending on the relative thicknesses. In the second approach, a paramagnetic Pt thin film is used to create Ir/Pt bilayer with a tunable $T_c$ in the same range. We present detailed study of fabrication and characterization of Ir-based low-$T_c$ films, and compare the experimental results to theoretical models. We show that Ir-based films with predictable and reproducible critical temperature can be consistently fabricated for use in large scale detector applications.Comment: 5 figures, accepted in the Journal of Applied Physic

The ‘heritagisation’ of the British seaside resort: The rise of the ‘old penny’ arcade.

Amusement arcades have long been a key component of the British seaside resort. For almost a century, they enjoyed popularity and success and became established as a quintessential feature of the British seaside holiday. However, the advent of home-based video games along with recent gambling legislation has led to a decline of the seaside amusement arcade sector. Arcades gained a reputation as unsavoury places and their appearance and fortunes often mirrored those of the resorts in which they were located. However, over the past decade, a new variant of the seaside amusement arcade has appeared, featuring mechanical machines working on pre-decimal currency. Such ‘old penny arcades’ frequently describe themselves as museums or heritage centres and they offer an experience based on a nostalgic affection for the ‘traditional’ seaside holiday. They have appeared in the context of an increasing interest in the heritage of the British seaside resort and constitute one element of the ‘heritagisation’ of such resorts. This paper argues that such arcades can be important elements of strategies to reposition and rebrand resorts for the heritage tourism market

Facing polyamorous lives: translation and validation of the attitudes towards polyamory scale in a Portuguese sample

© 2018, © 2018 College of Sexual and Relationship Therapists. Consensual Non-Monogamies (CNMs) have been receiving the attention of academics, however attitudes towards polyamory (ATP) are still a new field of research. We aim at studying the reliability and validity of the ATP scale in a Portuguese sample. The present analysis utilized cross-sectional data from 609 volunteers that completed the online survey with a socio-demographic questionnaire; the ATP scale; the Modern Heterosexism subscale of the Multidimensional Scale of Attitudes Toward Lesbians and Gay Men; the Rosenberg Self-Esteem Scale; and the Willingness to Engage in Non-Monogamy Scale. After randomly splitting the sample (1:1) for cross-validation purposes, Exploratory (EFA) and Confirmatory factor analysis (CFA) were conducted using Principal Axis Factoring (PAF) and Maximum Likelihood Estimation, respectively. Cronbach's alpha and item-total correlations were used to determine the internal consistency of the scale. Feasibility and acceptability were examined in terms of missing values, floor and ceiling effects. The ATP proved to be reliable (Cronbach’s alpha >.80). In the current study, the final structure of the scale, proved through CFA, included 6 items aggregated in a single factor. This final 6-item measure proved to have convergent, divergent and concurrent criterion validity. Implications for research in polyamory and CNMs are discussed

Sexual Priming, Gender Stereotyping, and Likelihood to Sexually Harass: Examining the Cognitive Effects of Playing a Sexually-Explicit Video Game

The present study examines the short-term cognitive effects of playing a sexually explicit video game with female “objectification” content on male players. Seventy-four male students from a university in California, U.S. participated in a laboratory experiment. They were randomly assigned to play either a sexually-explicit game or one of two control games. Participants’ cognitive accessibility to sexual and sexually objectifying thoughts was measured in a lexical decision task. A likelihood-to-sexually-harass scale was also administered. Results show that playing a video game with the theme of female “objectification” may prime thoughts related to sex, encourage men to view women as sex objects, and lead to self-reported tendencies to behave inappropriately towards women in social situations

The heterogeneity of family: Responses to representational invisibility by LGBTQ parents

This article draws on qualitative research data collected in semi-structured interviews conducted during 2013 and 2014 with 30 lesbian, gay, bisexual, trans, and queer (LGBTQ) parents living in England and Scotland. It explores how LGBTQ parents respond to media representations of families like theirs, and build narratives of family identity from limited cultural resources. Media, encompassing a range of cultural representational resources, including advertisements, television, books and films, produces specific knowledges about LGBTQ families. Participants argued that popular entertainment media (including Modern Family) offered a limited range of representations of LGBTQ parents and concretizes knowledge about the shape of families. I argue that available representations fail to acknowledge the diversity of non-heterosexual family forms and that this representational gap results in socio-cultural invisibility. I explore the responses LGBTQ parents had to such gaps and how they negotiated, or rejected representational meanings in order to consolidate new narratives of family

Infection-Associated Nuclear Degeneration in the Rice Blast Fungus Magnaporthe oryzae Requires Non-Selective Macro-Autophagy

addresses: School of Biosciences, University of Exeter, Exeter, Devon, United Kingdom.notes: PMCID: PMC3308974Freely-available open access article.The rice blast fungus Magnaporthe oryzae elaborates a specialized infection structure called an appressorium to breach the rice leaf surface and gain access to plant tissue. Appressorium development is controlled by cell cycle progression, and a single round of nuclear division occurs prior to appressorium formation. Mitosis is always followed by programmed cell death of the spore from which the appressorium develops. Nuclear degeneration in the spore is known to be essential for plant infection, but the precise mechanism by which it occurs is not known