Linear Types, Protocols, and Processes in Classical F°

Session types and typestate both promise a type system that can reason about protocol adherence. The complexity budgets of most programming languages, however, do not allow for new forms of types aimed at specific problem domains--even domains as broad as these. Classical F◦ --read F-pop --is a typed λ-calculus based on classical (i.e., full) linear logic, wherein session types arise naturally from the interaction between the usual sums, products, and implications of linear logic and a simple process model, with the dualizing negation of classical logic naturally accounting for how a protocol is seen by each of a channel\u27s endpoints. Classical F◦ expressions evaluate to processes, reminiscent of those in the π-calculus, that communicate over channels, but source expressions, rather than including processes and channels, employ only two novel control operators that account for process creation and communication. F◦ is introduced by way of its intuitionistic fragment, which even on its own can account for typestate: the combination of linearity and polymorphism leads to natural encodings of many programmer-specified protocols. In fact, any protocol expressible as a regular language can be encoded in an intuitionistic F◦ type. F◦ distinguishes between linear and unrestricted types by using kinds together with a notion of subkinding, avoiding the pitfalls of approaches based on type qualifiers or modalities; kinds are related by a subkinding order that allows unrestricted types to be treated as though they were linear. Soundness for intuitionistic and classical F◦ is proved both in the standard operational sense of preservation and progress and for an augmented semantics that shows more directly that the expected properties of linearity are preserved. This establishes the absence of deadlocks in closed, well-typed F◦ programs; it also guarantees that such programs will not leak processes as long as their result types are unrestricted

Automobile Liability Insurance in Nebraska—An Asset or Liability for the Out-of-State Defendant?

The ever-increasing use of the automobile by the American public has caused a corresponding increase in the amount of litigation resulting from this use. When this litigation involves a traffic accident occurring outside the jurisdiction of the state courts where the plaintiff brings suit, particular problems arise. One possible method of obtaining jurisdiction over a nonresident defendant for an out-of-state accident is to use the defendant\u27s automobile liability policy alleging it to be an asset. If the insurance company is doing business in the plaintiff\u27s state this asset may then be asserted as establishing the basis of a quasi in rem proceeding, thus allowing the plaintiff the convenience of his home forum. This comment examines the feasibility of obtaining this method of jurisdiction in Nebraska; (1) by using the policy of insurance to establish an administration proceeding in those cases where the defendant is deceased, and (2) by garnishing the insurance policy as an asset of the defendant in all other applicable cases

Nutrition and Cancer

The development and treatment of cancer presents a complex interaction between tumor and host. Provision of nutrients not only enables the maintenance of nutritional status, but also provides substrates and signals for immunity, tumor metabolism and protection of the host from treatment toxicities. Fat is one dietary element that has been explored for its role in cancer development. While the bulk of these studies have been observational or experimental, the evidence assembled suggests that dietary lipids behave uniquely to prevent or promote cancers. An additional aspect of cancer development is the role of adipose tissue as a source of, and a responder to, inflammatory signals that may be involved in tumor development. This Special Issue of Nutrients focuses on fat and cancer. The contributors to this Special Issue are well-recognized leaders in the field of cancer and have unique areas of focus including metabolism, immunology, biochemistry, epidemiology and nutrition. Each contribution highlights the latest research in these areas and what is known about fat and cancer with topics ranging from diet and cancer prevention, mechanisms of n-3 fatty acids on tumor development and the role of adipose tissue in cancer development and progression

Lolliproc: to Concurrency from Classical Linear Logic via Curry-Howard and Control

While many type systems based on the intuitionistic fragment of linear logic have been proposed, applications in programming languages of the full power of linear logic-including double-negation elimination-have remained elusive. Meanwhile, linearity has been used in many type systems for concurrent programs-e.g., session types-which suggests applicability to the problems of concurrent programming, but the ways in which linearity has interacted with concurrency primitives in lambda calculi have remained somewhat ad-hoc. In this paper we connect classical linear logic and concurrent functional programming in the language Lolliproc, which provides simple primitives for concurrency that have a direct logical interpretation and that combine to provide the functionality of session types. Lolliproc features a simple process calculus “under the hood” but hides the machinery of processes from programmers. We illustrate Lolliproc by example and prove soundness, strong normalization, and confluence results, which, among other things, guarantees freedom from deadlocks and race conditions

ABash: Finding Bugs in Bash Scripts

This paper describes the design and implementation of ABash, a tool for statically analyzing programs written in the bash scripting language. Although it makes no formal guarantees against missed errors or spurious warnings (largely due to the highly dynamic nature of bash scripts), ABash is useful for detecting certain common program errors that may lead to security vulnerabilities. In experiments with 49 bash scripts taken from popular Internet repositories, ABash was able to identify 20 of them as containing bugs of varying severity while yielding only a reasonable number of spurious warnings on both these scripts and the generally bug-free initialization scripts of the Ubuntu Linux distribution. ABash works by performing abstract interpretation of a bash script via an abstract semantics that accounts for shell variable expansion. The analysis is also parameterized by a collection of signatures that describe external program interfaces (for Unix commands, etc.), yielding an easily configurable and extensible framework for finding bugs in bash scripts

Fish oil supplementation and maintaining muscle mass in chronic disease: state of the evidence

PURPOSE OF REVIEW: Providing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the form of fish oils, to benefit muscle is an emerging area of interest. The aim of this work was to evaluate the current literature that has assessed muscle mass as an outcome during a fish oil intervention in any chronic disease. RECENT FINDINGS: The vast majority of studies published in the last 3 years (12 of 15) have been conducted in the oncological setting, in patients undergoing treatment for cancers of the gastrointestinal tract, breast, head and neck, lung, cervix, and hematological cancers. Three studies were conducted in patients with chronic obstructive pulmonary disease (COPD). Fish oil was provided as part of nutrient mixtures in 12 studies and as capsules in three studies. SUMMARY: Overall, the evidence for an effect of fish oil supplementation on muscle mass in patients with cancer undergoing treatment and in COPD remains unequivocal and reveals limited new knowledge in the area of fish oil supplementation in the cancer setting. Recent literature continues to provide mixed evidence on the efficacy of fish oil on muscle mass and function. The present review highlights challenges in comparing and interpreting current studies aimed at testing fish oil supplementation for muscle health

Photoluminescence of Ce3+ and Eu2+ in low-P ternesite from the Negev Desert, Israel

For the first time, the photoluminescence of ions of Ce3+ and Eu2+ in natural low-P ternesite has been measured. The emission bands of Ce3+ ions at 405, 426, and 440 nm and the corresponding excitation wavelengths suggest the presence of Ce3+ ions in three different cationic sites. In the photoluminescence spectra of Eu2+, emission bands at 530 and 620 nm can be seen that originate from two different cationic sites. In addition, it is demonstrated that an energy transfer occurs between Ce3+ and Eu2+ ions situated in those cationic sites where the force of the crystallic field is weakest. The photoluminescence spectra were obtained for a thin section sample with low contents of these two elements (41.2 ppm Ce, 2.11 ppm Eu)