A Design Strategy for Deadlock-Free Concurrent Systems

When building concurrent systems, it would be useful to have a collection of reusable processes to perform standard tasks. However, without knowing certain details of the inner workings of these components, one can never be sure that they will not cause deadlock when connected to some particular network. Here we describe a hierarchical method for designing complex networks of communicating processeswhich are deadlock-free.We use this to define a safe and simple method for specifying the communication interface to third party software components. This work is presented using the CSP model of concurrency and the occam2.1 programming language

Alien Registration- Welch, Martin (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24604/thumbnail.jp

Differences in Student Misbehavior After Completing In-School Suspension Between Rural High School and Suburban High School Students

This study investigated the differences that exist in rural and suburban high school student misbehavior after completing in-school suspension (ISS) in Alabama\u27s Mobile County Public School System. The independent variables of rural or suburban, gender, and ethnicity were used to determine the differences of the various groups. The archival discipline data of students assigned to ISS during the 2008-2009 school year were analyzed. Out of the 821 students assigned to ISS, 146 (17.8%) were not referred to the office again during the school year. There was a statistically significant relationship between rural or suburban and office referral after attending ISS. Suburban students (21.8%) were less likely to be referred to the office again than rural students (13.9%). No statistical differences were discovered between gender and misbehavior. A statistically significant relationship was found between ethnicity and office referral. All of the Asian students were referred to the office after attending ISS while 37.5% of Hispanic students received no additional office referrals. Black and Caucasian students were referred to the office again at about the same rate of just over 80%. Teacher demographic information and perceptions were gathered via questionnaire administered during the fall semester of 2009. Out of the combined total of 208 teachers at the two schools, 104 of them responded to the questionnaire. They were mostly middle-aged, Caucasian, and female with a master\u27s degree. Teachers indicated that they supported ISS but believed it needed to be improved. They were unsure how to improve the alternative discipline program. The instructors were also uncertain as to whether parents supported ISS and if the amount of counseling and academic support provided to students in the program needed to be increased. The educators disagreed that ISS students should only be assigned to students once a year and that the program deterred student misbehavior

Arming the troops: Post-translational modification of extracellular bacterial proteins

Funder: The Evelyn TrustFunder: The Cystic Fibrosis TrustFunder: British Lung Foundation; FundRef: https://doi.org/10.13039/501100000351Protein secretion is almost universally employed by bacteria. Some proteins are retained on the cell surface, whereas others are released into the extracellular milieu, often playing a key role in virulence. In this review, we discuss the diverse types and potential functions of post-translational modifications (PTMs) occurring to extracellular bacterial proteins

A Continuous-Flow Model for in vitro Cultivation of Mixed Microbial Populations Associated With Cystic Fibrosis Airway Infections.

The airways of people with cystic fibrosis (CF) provide a nutrient-rich environment which favours colonisation by a variety of bacteria and fungi. Although the dominant pathogen associated with CF airway infections is Pseudomonas aeruginosa, it is becoming increasingly clear that inter-species interactions between P. aeruginosa and other colonists in the airways may have a large impact on microbial physiology and virulence. However, there are currently no suitable experimental models that permit long-term co-culture of P. aeruginosa with other CF-associated pathogens. Here, we redress this problem by describing a "3R's-compliant" continuous-flow in vitro culture model which enables long-term co-culture of three representative CF-associated microbes: P. aeruginosa, Staphylococcus aureus and Candida albicans. Although these species rapidly out-compete one another when grown together or in pairs in batch culture, we show that in a continuously-fed setup, they can be maintained in a very stable, steady-state community. We use our system to show that even numerically (0.1%) minor species can have a major impact on intercellular signalling by P. aeruginosa. Importantly, we also show that co-culturing does not appear to influence species mutation rates, further reinforcing the notion that the system favours stability rather than divergence. The model is experimentally tractable and offers an inexpensive yet robust means of investigating inter-species interactions between CF pathogens

WITNESS ANONYMITY AT THE INTERNATIONAL CRIMINAL COURT: DUE PROCESS FOR DEFENDANTS, WITNESSES OR BOTH?

The question of how far and in what way to extend protection to witnesses in trials has manifested itself in institutions as diverse as the European Court of Human Rights (ECHR), the Committee of the International Covenant on Civil and Political Rights (ICCPR), the ad hoc criminal tribunals (International Criminal Tribunal for the former Yugoslavia, International Criminal Tribunal for Rwanda, the Special Court for Sierra Leone), and most recently the International Criminal Court (ICC). This is not surprising; as David Lusty has pointed out in his seminal analysis of the use of anonymous accusers, the question has arisen in almost every legal deliberative body for the past two thousand years

Does the Clam Mya truncata Regenerate Its Siphon after Predation by Walrus? An Experimental Approach

Walrus (Odobenus rosmarus) prey extensively on the bivalve Mya truncata, removing the siphons. We performed a simple experiment whereby the siphons from 27 M. truncata were removed, 33 controls were left intact, and the clams left on the sea bottom for a year. All the damaged Mya died; all but 2 controls lived. We conclude that M. truncata whose siphons have been grazed by walrus die, leaving over half the clam to predators or scavengers.

Ciprofloxacin binding to GyrA causes global changes in the proteome of Pseudomonas aeruginosa.

Ciprofloxacin is one of the most widely-used antibiotics, and has proven especially effective at controlling infections associated with the opportunistic human pathogen, Pseudomonas aeruginosa. In this work, we show that sub-inhibitory concentrations of ciprofloxacin induce discrete changes in the intracellular proteome. Central metabolism and cell envelope-associated functions are particularly affected. In spite of the low magnitude of the intracellular proteomic changes, we found that sub-lethal concentrations of ciprofloxacin had substantial effects on motility and exoprotein secretion. Crucially, the proteomic and phenotypic modulations that we observed were absolutely dependent upon the presence of wild-type GyrA; an isogenic strain of P. aeruginosa carrying a ciprofloxacin-insensitive form of GyrA (a T83→I mutant) did not display ciprofloxacin-dependent changes unless complemented with wild-type gyrA in trans. These results show that the diverse effects of sub-inhibitory ciprofloxacin on the cell are routed through its primary target in the cell, DNA gyrase.This work was supported by BBSRC grants BB/C500252/1 and BB/M019411/1

Determinacy of refinements to the difference hierarchy of co-analytic sets

In this paper we develop a technique for proving determinacy of classes of the form ω²-Π¹₁+Γ (a refinement of the difference hierarchy on Π¹₁ lying between ω²-Π¹₁ and (ω²+1)-Π¹₁) from weak principles, establishing upper bounds for the determinacy- strength of the classes ω²-Π¹₁+Σ^0_α for all computable α and of ω²-Π¹₁+Δ¹₁. This bridges the gap between previously known hypotheses implying determinacy in this region