New Notions of Reduction and Non-Semantic Proofs of β-Strong Normalization in Typed λ-Calculi

Two new notions of reduction for terms of the λ-calculus are introduced and the question of whether a λ-term is beta-strongly normalizing is reduced to the question of whether a λ-term is merely normalizing under one of the new notions of reduction. This leads to a new way to prove beta-strong normalization for typed λ-calculi. Instead of the usual semantic proof style based on Girard's "candidats de réductibilité'', termination can be proved using a decreasing metric over a well-founded ordering in a style more common in the field of term rewriting. This new proof method is applied to the simply-typed λ-calculus and the system of intersection types.

Borohydride Reduction of Fluorenone

A simple experiment to demonstrate nucleophilic addition to a carbonyl. Sodium borohydride-mediated reduction of fluorenone is a fast and high-yielding reaction that is suitable for beginning students. Students isolate their fluorenol product by recrystallization and characterize it by NMR and IR.

Addendum to "New Notions of Reduction and Non-Semantic Proofs of β-Strong Normalization in Typed λ-Calculi"

This is an addendum to our technical report BUCS TR-94-014 of December 19, 1994. It clarifies some statements, adds information on some related research, includes a comparison with research be de Groote, and fixes two minor mistakes in a proof.

Beta-Reduction As Unification

We define a unification problem ^UP with the property that, given a pure lambda-term M, we can derive an instance Gamma(M) of ^UP from M such that Gamma(M) has a solution if and only if M is beta-strongly normalizable. There is a type discipline for pure lambda-terms that characterizes beta-strong normalization; this is the system of intersection types (without a "top" type that can be assigned to every lambda-term). In this report, we use a lean version LAMBDA of the usual system of intersection types. Hence, ^UP is also an appropriate unification problem to characterize typability of lambda-terms in LAMBDA. It also follows that ^UP is an undecidable problem, which can in turn be related to semi-unification and second-order unification (both known to be undecidable).

Search Space Reduction in QoS Routing

To provide real-time service or engineer constrained-based paths, networks require the underlying routing algorithm to be able to find low-cost paths that satisfy given Quality-of-Service (QoS) constraints. However, the problem of constrained shortest (least-cost) path routing is known to be NP-hard, and some heuristics have been proposed to find a near-optimal solution. However, these heuristics either impose relationships among the link metrics to reduce the complexity of the problem which may limit the general applicability of the heuristic, or are too costly in terms of execution time to be applicable to large networks. In this paper, we focus on solving the delay-constrained minimum-cost path problem, and present a fast algorithm to find a near-optimal solution. This algorithm, called DCCR (for Delay-Cost-Constrained Routing), is a variant of the k-shortest path algorithm. DCCR uses a new adaptive path weight function together with an additional constraint imposed on the path cost, to restrict the search space. Thus, DCCR can return a near-optimal solution in a very short time. Furthermore, we use the method proposed by Blokh and Gutin to further reduce the search space by using a tighter bound on path cost. This makes our algorithm more accurate and even faster. We call this improved algorithm SSR+DCCR (for Search Space Reduction+DCCR). Through extensive simulations, we confirm that SSR+DCCR performs very well compared to the optimal but very expensive solution.

Hardware reduction in digital delta-sigma modulators via error masking - part I: MASH DDSM

Two classes of techniques have been developed to whiten the quantization noise in digital delta-sigma modulators (DDSMs): deterministic and stochastic. In this two-part paper, a design methodology for reduced-complexity DDSMs is presented. The design methodology is based on error masking. Rules for selecting the word lengths of the stages in multistage architectures are presented. We show that the hardware requirement can be reduced by up to 20% compared with a conventional design, without sacrificing performance. Simulation and experimental results confirm theoretical predictions. Part I addresses MultistAge noise SHaping (MASH) DDSMs; Part II focuses on single-quantizer DDSMs..

Proteomic approach to oxidative stress in Daphnia magna

The keystone aquatic organism Daphnia magna is extensively used to assess the toxicity of chemicals. This has recently lead to an increase in the omics literature focusing on daphnids, an increase fuelled by the sequencing of the Daphnia pulex genome. Yet, no omics study has looked directly at oxidative stress (OS) in daphnids, even though OS is of primary importance in the response of aquatic organisms to their changing environment and is often induced by anthropogenic xenobiotics. This thesis thus focuses on the application of redox-proteomics, the study of the oxidative modification of proteins, to D. magna Specifically, daphnids were exposed to copper or paraquat, two well studied prooxidants, and protein carbonyls were labelled with fluorescein-5-thiosemicarbazide prior to twodimensional electrophoresis (2DE). This showed clearly that both compounds affect a different portion of the proteome. The identified proteins indicated that energy metabolism was affected by paraquat, while copper induced a reduction of the heat shock response (heat shock proteins, proteases and chaperones) a counterintuitive result which may be adaptative to metal toxicity in arthropods. The same approach was then applied to the study of the toxicity mechanism of silver nanoparticles (AgNP), an increasingly utilised form of silver with expected environmental toxicity, and its comparison to silver nitrate. The results demonstrate that, although less toxic than silver ions, AgNP toxicity functions through a different mechanism. AgNP toxicity is thus not a product of silver dissolution and increased protein carbonylation indicates that AgNP cause OS. Interestingly three of the four tested compounds altered vitellogenin levels and oxidation. Vitellogenins could thus represent an interesting subproteome for the detection of stress in daphnids. Finally, an experiment with oxidised BSA demonstrates the applicability of solid phase hydrazide in the enrichment of undigested carbonylated proteins.

Anticipatory vigilance: A classic grounded theory of risk reduction and management in the perioperative setting

This research aimed to investigate the main concern facing nurses in minimising risk within the perioperative setting and to generate an explanatory substantive theory of how they resolve this through anticipatory vigilance. In the context of the perioperative setting, nurses encounter challenges in minimising risks for their patients on a continuous basis. Current explanations of minimising risk in the perioperative setting offers insights into how perioperative nurses undertake their work. Currently research in minimising risk is broadly related to dealing with errors as opposed to preventing them. To date, little is known about how perioperative nurses practice and maintain safety. This study was guided by the principles of classic grounded theory as described by Glaser (1978, 1998, 2001). Data was collected through individual unstructured interviews with thirty seven perioperative nurses (with varying lengths of experiences of working in the area) and thirty three hours of non-participant observation within eight different perioperative settings in the Republic of Ireland. Data was simultaneously collected and analysed. The theory of anticipatory vigilance emerged as the pattern of behaviour through which nurse’s deal with their main concern of minimising risk in a high risk setting. Anticipatory vigilance is enacted through orchestrating, routinising and momentary adapting within a spirit of trusting relations within the substantive area of the perioperative setting. This theory of offers an explanation on how nurses resolve their main concern of minimising risk within the perioperative setting. The theory of anticipatory vigilance will be useful to nurses in providing a comprehensive framework of explanation and understanding on how nurses deal with minimising risk in the perioperative setting. The theory links perioperative nursing, risk and vigilance together. Clinical improvements through understanding and awareness of the theory of anticipatory vigilance will result in an improved quality environment, leading to safe patient outcomes.

Oxidation-reduction potential and its influence on Cheddar cheese quality

Oxidation-reduction (redox) potential is a fundamental physicochemical parameter that affects the growth of microorganisms in dairy products and contributes to a balanced flavour development in cheese. Even though redox potential has an important impact on the quality of dairy products, it is not usually monitored in dairy industry. The aims of this thesis were to develop practical methods for measuring redox potential in cheese, to provide detailed information on changes in redox potential during the cheesemaking and cheese ripening and how this parameter is influenced by starter systems and to understand the relationship between redox potential and cheese quality. Methods were developed for monitoring redox potential during cheesemaking and early in ripening. Changes in redox potential during laboratory scale manufacture of Cheddar, Gouda, Emmental, and Camembert cheeses were determined. Distinctive kinetics of reduction in redox potential during cheesemakings were observed, and depended on the cheese technology and starter culture utilised. Redox potential was also measured early in ripening by embedding electrodes into Cheddar cheese at moulding together with the salted curd pieces. Using this approach it was possible to monitor redox potential during the pressing stage. The redox potential of Emmental cheese was also monitored during ripening. Moreover, since bacterial growth drives the reduction in redox potential during cheese manufacture and ripening, the ability of Lactococcus lactis strains to affect redox potential was studied. Redox potential of a Cheddar cheese extract was altered by bacterial growth and there were strain-specific differences in the nature of the redox potential/time curves obtained. Besides, strategies to control redox potential during cheesemaking and ripening were developed. Oxidizing or reducing agents were added to the salted curd before pressing and results confirmed that a negative redox potential is essential for the development of sulfur compounds in Cheddar cheese. Overall, the studies described in this thesis gave an evidence of the importance of the redox potential on the quality of dairy products. Redox potential could become an additional parameter used to select microorganisms candidate as starters in fermented dairy products. Moreover, it has been demonstrated that the redox potential influences the development of flavour component. Thus, measuring continuously changes in redox potential of a product and controlling, and adjusting if necessary, the redox potential values during manufacture and ripening could be important in the future of the dairy industry.

Reduction of quantity smoked predicts future cessation among older smokers.

AIM: To examine whether smokers who reduce their quantity of cigarettes smoked between two periods are more or less likely to quit subsequently. STUDY DESIGN: Data come from the Health and Retirement Study, a nationally representative survey of older Americans aged 51-61 in 1991 followed every 2 years from 1992 to 1998. The 2064 participants smoking at baseline and the first follow-up comprise the main sample. MEASUREMENTS: Smoking cessation by 1996 is examined as the primary outcome. A secondary outcome is relapse by 1998. Spontaneous changes in smoking quantity between the first two waves make up the key predictor variables. Control variables include gender, age, education, race, marital status, alcohol use, psychiatric problems, acute or chronic health problems and smoking quantity. FINDINGS: Large (over 50%) and even moderate (25-50%) reductions in quantity smoked between 1992 and 1994 predict prospectively increased likelihood of cessation in 1996 compared to no change in quantity (OR 2.96, P<0.001 and OR 1.61, P<0.01, respectively). Additionally, those who reduced and then quit were somewhat less likely to relapse by 1998 than those who did not reduce in the 2 years prior to quitting. CONCLUSIONS: Reducing successfully the quantity of cigarettes smoked appears to have a beneficial effect on future cessation likelihood, even after controlling for initial smoking level and other variables known to impact smoking cessation. These results indicate that the harm reduction strategy of reduced smoking warrants further study.

THE DEVELOPMENT AND FEASIBILITY OF A BRIEF RISK REDUCTION INTERVENTION FOR NEWLY HIV-DIAGNOSED MEN WHO HAVE SEX WITH MEN.

Men who have sex with men (MSM) represent more than half of all new HIV infections in the United States. Utilizing a collaborative, community based approach, a brief risk reduction intervention was developed and pilot tested among newly HIV-diagnosed MSM receiving HIV care in a primary care setting. Sixty-five men, within 3 months of diagnosis, were randomly assigned to the experimental condition or control condition and assessed at baseline, 3-month, and 6-month follow-up. Effect sizes were calculated to explore differences between conditions and over time. Results demonstrated the potential effectiveness of the intervention in reducing risk behavior, improving mental health, and increasing use of ancillary services. Process evaluation data demonstrated the acceptability of the intervention to patients, clinic staff, and administration. The results provide evidence that a brief intervention can be successfully integrated into HIV care services for newly diagnosed MSM and should be evaluated for efficacy.

Human dimensions of bycatch reduction technology: Current assumptions and directions for future research

Bycatch reduction technology (BRT) modifies fishing gear to increase selectivity and avoid capture of non-target species, or to facilitate their non-lethal release. As a solution to fisheries-related mortality of non-target species, BRT is an attractive option; effectively implemented, BRT presents a technical 'fix' that can reduce pressure for politically contentious and economically detrimental interventions, such as fisheries closures. While a number of factors might contribute to effective implementation, our review of BRT literature finds that research has focused on technical design and experimental performance of individual technologies. In contrast, and with a few notable exceptions, research on the human and institutional context of BRT, and more specifically on how fishers respond to BRT, is limited. This is not to say that fisher attitudes are ignored or overlooked, but that incentives for fisher uptake of BRT are usually assumed rather than assessed or demonstrated. Three assumptions about fisher incentives dominate: (1) economic incentives will generate acceptance of BRT; (2) enforcement will generate compliance with BRT; and (3) 'participation' by fishers will increase acceptance and compliance, and overall support for BRT. In this paper, we explore evidence for and against these assumptions and situate our analysis in the wider social science literature on fisheries. Our goal is to highlight the need and suggest focal areas for further research. © Inter-Research 2008.

Reduction of malaria prevalence by indoor residual spraying: a meta-regression analysis.

Indoor residual spraying (IRS) has become an increasingly popular method of insecticide use for malaria control, and many recent studies have reported on its effectiveness in reducing malaria burden in a single community or region. There is a need for systematic review and integration of the published literature on IRS and the contextual determining factors of its success in controlling malaria. This study reports the findings of a meta-regression analysis based on 13 published studies, which were chosen from more than 400 articles through a systematic search and selection process. The summary relative risk for reducing malaria prevalence was 0.38 (95% confidence interval = 0.31-0.46), which indicated a risk reduction of 62%. However, an excessive degree of heterogeneity was found between the studies. The meta-regression analysis indicates that IRS is more effective with high initial prevalence, multiple rounds of spraying, use of DDT, and in regions with a combination of Plasmodium falciparum and P. vivax malaria.

THE STEAM-JET AEROSOL COLLECTOR

A new principle of sampling aerosol particles by means of steam injection with the consequent collection of grown droplets has been established. An air stream free of water-soluble gases is rapidly mixed with steam. The resulting supersaturation causes aerosol particles to grow into droplets. The droplets containing dissolved aerosol species are then collected by two cyclones in series. The solution collected in the cyclones is constantly pumped out and can be on- or off-line analysed by means of ion chromatography or flow injection analysis. On the basis of the new sampling principle a prototype of an aerosol sampler was designed which is capable of sampling particles quantitatively down to several nanometres in diameter. The mass sampling efficiency of the instrument was found to be 99\%. The detection limit of the sampler for ammonium, sulphate, nitrate and chloride ions is below 0.7 mu g m(-3). By reduction of an already identified source of contamination, much lower detection limits can be achieved. During measurements the sampler proved to be stable, working without any assistance for extended periods of time. Comparison of the sampler with filter packs during measurements of ambient air aerosols showed that the sampler gives good results.

G protein signaling and vein graft intimal hyperplasia: reduction of intimal hyperplasia in vein grafts by a Gbetagamma inhibitor suggests a major role of G protein signaling in lesion development.

Vein grafting results in the development of intimal hyperplasia with accompanying changes in guanine nucleotide-binding (G) protein expression and function. Several serum mitogens that act through G protein-coupled receptors, such as lysophosphatidic acid, stimulate proliferative pathways that are dependent on the G protein betagamma subunit (Gbetagamma)-mediated activation of p21ras. This study examines the role of Gbetagamma signaling in intimal hyperplasia by targeting a gene encoding a specific Gbetagamma inhibitor in an experimental rabbit vein graft model. This inhibitor, the carboxyl terminus of the beta-adrenergic receptor kinase (betaARK(CT)), contains a Gbetagamma-binding domain. Vein graft intimal hyperplasia was significantly reduced by 37% (P<0.01), and physiological studies demonstrated that the normal alterations in G protein coupling phenotypically seen in this model were blocked by betaARK(CT) treatment. Thus, it appears that Gbetagamma-mediated pathways play a major role in intimal hyperplasia and that targeting inhibitors of Gbetagamma signaling offers novel intraoperative therapeutic modalities to inhibit the development of vein graft intimal hyperplasia and subsequent vein graft failure.