The Iterated Weakest Link

We outline a model for security investment that reflects dynamic interaction between a defender, who faces uncertainty, and an attacker, who repeatedly targets the weakest link. Using the model, we derive and compare optimal security investment over multiple periods, exploring the delicate balance between proactive and reactive security investment.     

The fundamentals of barriers to reverse engineering and their implementation into mechanical components

Reverse engineering is a common design strategy in industry. It is a term that has come to encompass a large array of engineering and design activities in the literature; however, in its basic form, reverse engineering is simply the process of extracting information about a product from the product itself. Depending on its use, it may or may not be advantageous to utilize a reverse engineering strategy. As with any rational decision, reverse engineering is only favorable when the benefits from its use outweigh the investment. Therefore, a general understanding of the principles that increase the difficulty or investment required to reverse engineer mechanical products would be helpful for everyone affected by reverse engineering activities. In this paper, we articulate and explore these fundamental principles after reviewing examples from the literature and from our own experience. We then use the principles as a basis for the development of a methodology to build barriers to reverse engineering into new products.     

Application of Semiochemicals to Assess the Biodiversity of Subcortical Insects following an Ecosystem Disturbance in a Sub-boreal Forest

From 2000 through 2003 we used semiochemical-baited traps in northeastern Minnesota, USA, to assess changes in assemblages of subcortical forest insects after a catastrophic wind storm in 1999 and subsequent (1999–2000) fuel-reduction activities (salvage-logging and prescribed-burning). We determined the regional efficacy of fifteen semiochemical blends (pheromones and kairomones) as attractants for target and non-target subcortical insect species (Coleoptera: Anthribidae, Buprestidae, Cerambycidae, Cleridae, Cucujidae, Curculionidae, Histeridae, Nemonychidae, Salpingidae, Scolytidae, Tenebrionidae, and Hymenoptera: Siricidae). During the four summers, we trapped 86,471 subcortical insects (143 species) in baited and unbaited Lindgren funnel traps, and 500 beetles (44 species) in baited and unbaited pitfall traps. We report 23 new state collection records of subcortical insects from Minnesota. Trap catches of subcortical insects were greatest in the wind-disturbed areas 2 years after the event, and declined thereafter. Similar trends were observed for subcortical insects in the burned areas. Both wind-disturbance and burning increased the subcortical insect species richness and diversity on the landscape. The subcortical insect species compositions of the salvaged and burned forest areas differed from those of the undisturbed and wind-disturbed areas. Trap catches of subcortical insects in response to semiochemical treatments also varied with year of sampling and land-area treatment. The greatest diversity of subcortical beetle species was in traps baited with attractants for the scolytids, Dendroctonus valens [(+)-α-pinene and (−)-β-pinene] and Dryocoetes spp. [exo-brevicomin and (−)-α-pinene], perhaps reflecting the generic nature of the baits. The most distinct species compositions were collected in response to the woodborer and Dendroctonus simplex baits, whereas the species compositions in traps with the D. valens and Dryocoetes spp. baits, and the unbaited funnel trap were the most similar. The variation in trap catch with time and across landscapes suggests that the responses of subcortical insects to semiochemicals are more complex than previously appreciated.     

The use of bovine serum protein as an oral support therapy following coronavirus challenge in calves

The objective of this experiment was to investigate the therapeutic efficacy of a supplemental bovine serum protein blend fed to calves challenged with virulent coronavirus. Twelve Holstein bull calves (approximately 3 wk of age) were allocated by initial body weight to Control (n = 5) and treated (n = 7) groups. On d 0, all calves were orally challenged with 1 x 10(7) plaque-forming units of virulent coronavirus isolate. Infection was allowed to progress for 24 h before treatment was started. On d 1, treated calves began receiving 160 g of dry bovine serum powder (16 g IgG) mixed into milk replacer powder (67 g) at both an a.m. and p.m. feeding. Control calves received only milk replacer powder (227 g) at both feedings. Response to coronavirus challenge and dietary treatment was monitored prior to a.m. and p.m. feeding by the collection of multiple clinical measures. Fecal consistency was decreased by coronavirus challenge but was not affected by dietary treatment. Mean daily rectal temperature and heart rate were not affected by dietary treatment. Average packed cell volume was higher in treated calves than in control (35.0 and 27.0%). Coronavirus challenge resulted in an immediate increase in respiration rate, decreasing by d 7. Control calves tended to have a greater average respiration rate compared with treated (28.7 vs. 26.8 breaths/min). Treated calves had a higher average feed intake than control (0.57 vs. 0.44 kg/d). These data suggest that bovine-serum supplemented milk replacer may decrease the severity of disease in young calves exposed to coronavirus.     

Correction to Perruchet et al. (2006).

Reports an error in "Do We Need Algebraic-Like Computations? A Reply to Bonatti, Pena, Nespor, and Mehler (2004)" by Pierre Perruchet, Ronald Peereman, and Michael D. Tyler (Journal of Experimental Psychology: General, 2006[May], 135(2), 322-326). The page numbers that Dr. Perruchet cited from Dr. Bonatti et al.'s article were printed incorrectly. These page numbers should appear as follows in the correction. (The following abstract of this article originally appeared in record 2006-06642-011.) L. L. Bonatti, M. Pena, M. Nespor, and J. Mehler (see record 2006-06642-010) argued that P. Perruchet, M. D. Tyler, N. Galland, and R. Peereman (see record 2004-21166-008) confused the notions of segmentation and generalization by ignoring the evidence for generalization in M. Pena, L. L. Bonatti, M. Nespor, and J. Mehler (see record 2002-06215-001). In this reply, the authors reformulate and complement their initial arguments, showing that their way of dealing with segmentation and generalization is not due to confusion or ignorance but rather to the fact that the tests used in Pena et al. make it likely that neither segmentation nor generalization were captured in their experiments. Finally, the authors address the challenge posed by Pena et al. of accounting for the whole pattern of their results without invoking rule-based, algebraic-like computations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oracle Erp and Network Computing Architecture: Implementation and Performance

Enterprise resource planning (ERP) systems enable firms to attain information technology integration. Such integration results in a uniform information system across the entire organization, thus augmenting performance. in this article, the issues and performance of Oracle ERP are discussed based on perspicacious exploratory analyses conducted in two manufacturing firms located in Ohio and Wisconsin. the factors of influence to implement Oracle ERP systems, various issues involved in the process of implementation, and performance of the systems are discussed in detail. the triangulation technique was used to make sure that the qualitative and quantitative findings were congruent. the results of the quantitative analysis and details of the constructs and items identified to measure the constructs are explained elsewhere by the first author. Oracle ERP systems enabled these firms to perform better by simplifying and streamlining their information retrieval and dissemination processes. Oracle's Web-based network computing architecture (NCA) offers many advantages, such as higher scalability and better coordination with suppliers and customers. These case studies provided a foundation for future research to build theoretical models.     

Modeling the combined effect of static and varying phase distortions on the performance of adaptive optical systems

The end-to-end performance achieved by an adaptive optical (AO) imaging system is determined by a combination of the residual time-varying phase distortions associated with atmospheric turbulence and the quasi-static unsensed and uncorrectable aberrations in the optical system itself. Although the effects of these two errors on the time-averaged Strehl ratio and the time-averaged optical transfer function (OTF) of the AO system are not formally separable, such an approximation is found to be accurate to within a few percent for a range of representative residual wave-front errors. In these calculations, we combined static optical system aberrations and time-varying residual phase distortion characteristics of a deformable mirror fitting error, wave-front sensor noise, and anisoplanatism. The static aberrations consist of focus errors of varying magnitudes as well as a combination of unsensed and uncorrectable mirror figure errors derived from modeling by the Gemini 8-Meter Telescopes Project. The overall Strehl ratios and OTF's that are due to the combined effect of these error sources are well approximated as products of separate factors for the static and time-varying aberrations, as long as the overall Strehl ratio that is due to both errors is greater than approximately 0.1. For lower Strehl ratios, the products provide lower bounds on the actual values of the Strehl ratio and the OTF. The speckle transfer function is also well approximated by a product of two functions, but only where AO compensation is sufficiently good that speckle imaging techniques are usually not required.     

Carcinoids of unknown origin: comparative analysis with foregut, midgut, and hindgut carcinoids

The purpose of this study was to analyze our results of surgical treatment of arthrogryposis of the elbow and to compare our tendon transfer results using range of motion (ROM) criteria versus functional use criteria. Eighteen tendon transfers for elbow flexion in 14 children with arthrogryposis with an average follow-up period of 4 years (range, 1-14 years) and 6 elbow capsulotomies with triceps lengthening in 6 children with arthrogryposis with an average follow-up period of 5 years (range, 2-9 years) were evaluated. Each child was assessed by a questionnaire regarding functional use of the upper extremity, physical examination of ROM and strength, and a videotaped activities of daily living evaluation. Tendon transfer results were classified and compared using 2 methods of evaluation: postoperative strength and ROM and effective functional use of the tendon transfer to perform activities of daily living. The 6 elbow capsulotomies improved from an average preoperative arc of 17 degrees of motion (average extension, -2 degrees; average flexion, 19 degrees) to an average final follow-up arc of 67 degrees (average extension, -25 degrees; average flexion, 92 degrees). The 18 tendon transfers evaluated by strength and ROM criteria showed 9 triceps to biceps transfers in 9 arms (7 good, 1 fair, and 1 poor), 5 pectoralis to biceps transfers in 4 arms (1 good, 3 fair, and 1 poor), and 4 latissimus dorsi to biceps transfers in 3 arms (2 good and 2 fair). Evaluation by functional use criteria gave the same result in 13 transfers and downgraded the result in 5; the downgraded results were due to resultant flexion contracture or limited functional use because the transfer was in the nondominant arm. Based on this review, optimal surgical candidates for tendon transfer are children older than 4 years, who have full passive ROM of the elbow in the dominant arm, and at least grade 4 strength of the muscle to be transferred.     

Par-4 is a mediator of neuronal degeneration associated with the pathogenesis of Alzheimer disease

Prostate apoptosis response-4 (Par-4) is a protein containing both a leucine zipper and a death domain that was isolated by differential screening for genes upregulated in prostate cancer cells undergoing apoptosis. Par-4 is expressed in the nervous system, where its function is unknown. In Alzheimer disease (AD), neurons may die by apoptosis, and amyloid beta-protein (A beta) may play a role in this. We report here that Par-4 expression is increased in vulnerable neurons in AD brain and is induced in cultured neurons undergoing apoptosis. Blockade of Par-4 expression or function prevented neuronal apoptosis induced by Ab and trophic factor withdrawal. Par-4 expression was enhanced, and mitochondrial dysfunction and apoptosis exacerbated, in cells expressing presenilin-1 mutations associated with early-onset inherited AD.     

Energy use in Minnesota State-owned facilities

This paper describes and analyzes the contents of a large data base containing information on monthly energy use at state-owned facilities in Minnesota. The data base, managed by the State Department of Administration, includes information on 42 community colleges, state universities, hospitals, prisons, and the St. Paul Capitol Complex. The data span a seven year period (1972 – 1978) and include about 3,500 observations.Several data base management issues are discussed. These include errors and their correction, development of simple and consistent definitions for key terms, and collection of information on key determinants of energy use at these facilities.Total annual energy use at these 42 institutions averaged 245 kBtu/ft² (2.78 GJ/m²) for 1978. Fossil fuels accounted for 56% of this total; electricity accounted for the remainder. Energy use at the Capitol Complex, hospitals and prisons was higher than average.Regression equations were developed to predict monthly heating fuel use and total energy use. These equations show that more than 60% of the variation in energy use per unit floorspace can be explained by a few variables: heating degree days; electricity and fossil fuel prices; number of buildings; number of boilers; facility age; and whether or not the facility is all electric.