Distributed applications are difficult to program reliably and securely. Dependently typed functional languages promise to prevent broad classes of errors and vulnerabilities, and to enable program verification to proceed side-by-side with development. However, as recursion, effects, and rich libraries are added, using types to reason about programs, specifications, and proofs becomes challenging.We present F , a full-fledged design and implementation of a new dependently typed language for secure distributed programming. Unlike prior languages, F provides arbitrary recursion while maintaining a logically consistent core; it enables modular reasoning about state and other effects using affine types; and it supports proofs of refinement properties using a mixture of cryptographic evidence and logical proof terms. The key mechanism is a new kind system that tracks several sub-languages within F and controls their interaction. F subsumes two previous languages, F7 and Fine. We prove type soundness (with proofs mechanized in Coq) and logical consistency for F .We have implemented a compiler that translates F to .NET bytecode, based on a prototype for Fine. F provides access to libraries for concurrency, networking, cryptography, and interoperability with C#, F#, and the other .NET languages. The compiler produces verifiable binaries with 60% code size overhead for proofs and types, as much as a 45x improvement over the Fine compiler, while still enabling efficient bytecode verification.To date, we have programmed and verified more than 20,000 lines of F including (1) new schemes for multi-party sessions;(2) a zero-knowledge privacy-preserving payment protocol; (3) a provenance-aware curated database; (4) a suite of 17 web-browser extensions verified for authorization properties; and (5) a cloudhosted multi-tier web application with a verified reference monitor.

Bone marrow stromal cells (BMSC) are pluripotent progenitor cells that can regenerate different skeletal tissues in response to environmental signals. In this study, we used highly porous, structurally stable three-dimensional polymer foams in conjunction with specific regulatory molecules to selectively differentiate mammalian BMSC into either cartilaginous or bone-like tissues. Bovine BMSC were expanded in monolayers and cultured on 5-mm-diameter, 2-mm-thick foams made of poly(lactic-co-glycolic acid) and poly(ethylene glycol). Constructs maintained their original size and shape for up to 4 weeks of culture and supported BMSC growth and production of extracellular matrix (ECM). By proper use of chondrogenic (dexamethasone, insulin, transforming growth factor-beta1) or osteogenic (dexamethasone, beta-glycerophosphate) medium supplements, we could control whether the generated ECM was cartilaginous (containing collagen type II and sulfated glycosaminoglycans) or bone-like (containing osteocalcin, osteonectin, and mineralized foci). After 4 weeks of cultivation, cartilaginous and bone-like ECM were uniformly distributed throughout the construct volume and respectively represented 34.2 +/- 9.3% and 12.6 +/- 3.2% of the total available area. BMSC culture on poly(lactic-co-glycolic acid)/poly(ethylene glycol) foams provides a three-dimensional model system to study the development of mesenchymal tissues in vitro and has potential applications in engineering autologous grafts for skeletal tissue repair.

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It is becoming increasingly important for applications to protect sensitive data. With current techniques, the programmer bears the burden of ensuring that the application's behavior adheres to policies about where sensitive values may flow. Unfortunately, privacy policies are difficult to manage because their global nature requires coordinated reasoning and enforcement. To address this problem, we describe a programming model that makes the system responsible for ensuring adherence to privacy policies. The programming model has two components: 1) core programs describing functionality independent of privacy concerns and 2) declarative, decentralized policies controlling how sensitive values are disclosed. Each sensitive value encapsulates multiple views; policies describe which views are allowed based on the output context. The system is responsible for automatically ensuring that outputs are consistent with the policies. We have implemented this programming model in a new functional constraint language named Jeeves. In Jeeves, sensitive values are introduced as symbolic variables and policies correspond to constraints that are resolved at output channels. We have implemented Jeeves as a Scala library using an SMT solver as a model finder. In this paper we describe the dynamic and static semantics of Jeeves and the properties about policy enforcement that the semantics guarantees. We also describe our experience implementing a conference management system and a social network.

Distributed applications are difficult to program reliably and securely. Dependently typed functional languages promise to prevent broad classes of errors and vulnerabilities, and to enable program verification to proceed side-by-side with development. However, as recursion, effects, and rich libraries are added, using types to reason about programs, specifications, and proofs becomes challenging.We present F ⋆ , a full-fledged design and implementation of a new dependently typed language for secure distributed programming. Unlike prior languages, F ⋆ provides arbitrary recursion while maintaining a logically consistent core; it enables modular reasoning about state and other effects using affine types; and it supports proofs of refinement properties using a mixture of cryptographic evidence and logical proof terms. The key mechanism is a new kind system that tracks several sub-languages within F ⋆ and controls their interaction. F ⋆ subsumes two previous languages, F7 and Fine. We prove type soundness (with proofs mechanized in Coq) and logical consistency for F ⋆ .We have implemented a compiler that translates F ⋆ to .NET bytecode, based on a prototype for Fine. F ⋆ provides access to libraries for concurrency, networking, cryptography, and interoperability with C#, F#, and the other .NET languages. The compiler produces verifiable binaries with 60% code size overhead for proofs and types, as much as a 45x improvement over the Fine compiler, while still enabling efficient bytecode verification.To date, we have programmed and verified more than 20,000 lines of F ⋆ including (1) new schemes for multi-party sessions; (2) a zero-knowledge privacy-preserving payment protocol; (3) a provenance-aware curated database; (4) a suite of 17 web-browser extensions verified for authorization properties; and (5) a cloudhosted multi-tier web application with a verified reference monitor.

No abstract

We present an approach for dynamic information flow control across the application and database. Our approach reduces the amount of policy code required, yields formal guarantees across the application and database, works with existing relational database implementations, and scales for realistic applications. In this paper, we present a programming model that factors out information flow policies from application code and database queries, a dynamic semantics for the underlying λ JDB core language, and proofs of termination-insensitive non-interference and policy compliance for the semantics. We implement these ideas in Jacqueline, a Python web framework, and demonstrate feasibility through three application case studies: a course manager, a health record system, and a conference management system used to run an academic workshop. We show that in comparison to traditional applications with hand-coded policy checks, Jacqueline applications have 1) a smaller trusted computing base, 2) fewer lines of policy code, and 2) reasonable, often negligible, overheads.

-A total of 360 bark-to-bark-through-pith wood strips were sampled at breast height from 180 trees in 30 open-pollinated families from two rotation-aged genetic trials to study inheritance, age-age genetic correlation, and early selection efficiency for wood quality traits in radiata pine. Wood strips were evaluated by SilviScan and annual pattern and genetic parameters for growth, wood density, microfibril angle (MFA), and stiffness (modulus of elasticity: MOE) for early to rotation ages were estimated. Annual ring growth was the largest between ages 2-5 years from pith, and decreased linearly to ages 9-10. Annual growth was similar and consistent at later ages. Wood density was the lowest near the pith, increased steadily to age 11-15 years, then was relatively stable after these ages. MFA was highest (35• ) near the pith and reduced to about 10• at age 10-15 years. MFA was almost unchanged at later ages. MOE increased from about 2.5 GPa near the pith to about 20 GPa at ages 11-15 years. MOE was relatively unchanged at later ages. Wood density and MOE were inversely related to MFA. Heritability increased from zero near the pith and stabilised at ages 4 or 5 for all four growth and wood quality traits (DBH, density, MFA and MOE). Across age classes, heritability was the highest for area-weighted density and MFA, lowest for DBH, and intermediate for MOE. Age-age genetic correlations were high for the four traits studied. The genetic correlation reached 0.8 after age 7 for most traits. Early selection for density, MFA and MOE were very effective. Selection at age 7-8 has similar effectiveness as selection conducted at rotation age for MFA and MOE and at least 80% effective for wood density.early selection / microfibril angle / modulus of elasticity / wood density / radiata pine Résumé -Efficacité d'une sélection précoce pour les propriétés du bois adulte chez le pin radiata. Cette étude a pour objectif d'estimer les paramètres génétiques (héritabilités et corrélations juvéniles-adultes) pour différentes propriétés du bois chez le pin radiata et d'évaluer l'efficacité d'une sélection précoce. Trois cent soixante échantillons diamétraux de bois ont été prélevés dans deux dispositifs génétiques adultes sur trente familles de pin radiata issues de pollinisation libre, puis analysés avec le SilviScan . Les caractéristiques annuelles de la croissance, de la densité du bois, de l'angle des microfibrilles (MFA) et de la rigidité (module d'élasticité : MOE) ont été analysées et les paramètres génétiques de ces caractères ont été estimés du stade juvénile à l'âge de la révolution. La croissance radiale est la plus forte entre 2 et 5 ans (depuis la moelle) puis décroît linéairement jusqu'à neuf-dix ans et se stabilise ensuite. La densité du bois est la plus faible près de la moelle ; elle augmente fortement jusqu'à 11-15 ans puis se stabilise. MFA est le plus élevé (35 • ) près de la moelle ; il diminue ensuite pour atteindre environ 10• vers 10-15 ans. MFA ne varie pratiquement plus au-delà de cet âge. MOE passe d...