A History of the Eastern Larch Beetle, \u3ci\u3eDendroctonus Simplex\u3c/i\u3e (Coleoptera: Scolytidae), in North America

The eastern larch beetle, Dendroctonus simplex, is reputedly a secondary pest but may attack and kill tamarack and ornamental larches throughout Canada, the northeastern United Stales, and Alaska. Isolated infestations of this pest have been reported for over 100 years. The first recorded widespread outbreaks of D. simplex started in eastern Canada and the northeastern United States as well as in Alaska in the mid-1970s. During the outbreak in the Atlantic provinces, in excess of 1.4 million m3 of tamarack was killed. No damage estimates are available for Quebec and the United States. Insect defoliators were the most common factors predisposing tamarack to beetle attack

Wood borer control in spruce logs with p-dichlorobenzene and plastic sheeting (Coleoptera: Cerambycidae)

Fumigation under plastic sheeting of white spruce (Picea glauca (Moench) Voss) logs with crystalline p-dichlorobenzene (PDB) for 26 days killed more than 95% of cerambycid and other wood borer larvae under the bark and in the wood, at the lowest dosage of 8g of chemical per cubic meter of log plus air space volume. The long treatment-duration promoted the discoloration of logs by stain fungi. When treatments were shortened to 2, 4 and 7 days, and the PDB was dissolved in trichloroethylene, the lowest dosage at the shortest duration killed more than 80% of the wood borer larvae

Fabrication of cartilage-inspired hydrogel/entangled polymer–elastomer structures possessing poro-elastic properties

The ability to replicate the load-bearing properties of articular cartilage is attractive for many engineering applications, particularly bearings where low friction, low wear, and high durability are required. Hydrogels are widely used materials spanning many diverse applications owing to their lubricity and unique mechanical/chemical properties. The poor mechanical characteristics of conventional hydrogels, especially their compressive behavior, limit their application in load-bearing applications despite their favorable properties such as poro/viscoelasticity and lubricity. This paper demonstrates a cartilage-inspired approach to produce a structure that benefits from water-swelling resistant and ultrafast recovery behavior of elastomers as well as the stress-relaxation and energy dissipation properties of hydrogels. A method is presented in this work to fabricate interconnected macro-porous elastomers based on sintering poly(methyl methacrylate) beads. The porous elastomer imparted structural support and resilience to its composite with an infused-grafted hydrogel. At 30% strain and depending upon the strain rate, the composite exhibited a load-bearing behavior that was 14–19 times greater than that of pristine hydrogel and approximately 3 times greater than that of the porous elastomer. The equilibrium elastic modulus of the composite was 452 kPa at a strain range of 10%–30%, which was close to the values reported for the modulus of cartilage tested with similar experimental parameters defined in this study. The dissipated energy for the composite at strain rates of 1 and 10–3 s–1 was enhanced by 25-, 25-, 5-, and 15-fold as compared to that for the pristine hydrogel and the porous elastomer, respectively. The cyclic loading tests at two strain rates showed that the composite immediately recovers its load-bearing properties with the maximum load recovery staying above 95% of its initial values throughout the testing. The permeability of the structures was measured experimentally, and the results showed a decrease of permeability by 3 orders of magnitude following hydrogel grafting

Robust and High-Performance Soft Inductive Tactile Sensors based on the Eddy-Current Effect

Tactile sensors are essential for robotic systems to interact safely and effectively with the external world, they also play a vital role in some smart healthcare systems. Despite advances in areas including materials/composites, electronics and fabrication techniques, it remains challenging to develop low cost, high performance, durable, robust, soft tactile sensors for real-world applications. This paper presents the first Soft Inductive Tactile Sensor (SITS) which exploits an inductance-transducer mechanism based on the eddy-current effect. SITSs measure the inductance variation caused by changes in AC magnetic field coupling between coils and conductive films. Design methodologies for SITSs are discussed by drawing on the underlying physics and computational models, which are used to develop a range of SITS prototypes. An exemplar prototype achieves a state-of-the-art resolution of 0.82 mN with a measurement range over 15 N. Further tests demonstrate that SITSs have low hysteresis, good repeatability, wide bandwidth, and an ability to operate in harsh environments. Moreover, they can be readily fabricated in a durable form and their design is inherently extensible as highlighted by a 4x4 SITS array prototype. These outcomes show the potential of SITS systems to further advance tactile sensing solutions for integration into demanding real-world applications

A predictive model for discrete cell gravure roll coating

A heterogeneous multiscale model for discrete cell gravure roll coating is presented along with experimental results for the purpose of model validation. The cell volume, generalized cell shape, and the gravure patterning are considered in the model which is based on a multiscale description of the flow in the coating bead. The inclusion of a web-to-roll contact term accounts for the special gravure case when the web-roll separation tends to zero. The results show how the coating bead responds to changes in operating conditions. These are presented as profile plots of the fluid properties and coating bead shape

The epidemiology of injuries across the weight-training sports

Background: Weight-training sports, including weightlifting, powerlifting, bodybuilding, strongman, Highland Games, and CrossFit, are weight-training sports that have separate divisions for males and females of a variety of ages, competitive standards, and bodyweight classes. These sports may be considered dangerous because of the heavy loads commonly used in training and competition. Objectives: Our objective was to systematically review the injury epidemiology of these weight-training sports, and, where possible, gain some insight into whether this may be affected by age, sex, competitive standard, and bodyweight class. Methods: We performed an electronic search using PubMed, SPORTDiscus, CINAHL, and Embase for injury epidemiology studies involving competitive athletes in these weight-training sports. Eligible studies included peer-reviewed journal articles only, with no limit placed on date or language of publication. We assessed the risk of bias in all studies using an adaption of the musculoskeletal injury review method. Results: Only five of the 20 eligible studies had a risk of bias score ≥75 %, meaning the risk of bias in these five studies was considered low. While 14 of the studies had sample sizes >100 participants, only four studies utilized a prospective design. Bodybuilding had the lowest injury rates (0.12–0.7 injuries per lifter per year; 0.24–1 injury per 1000 h), with strongman (4.5–6.1 injuries per 1000 h) and Highland Games (7.5 injuries per 1000 h) reporting the highest rates. The shoulder, lower back, knee, elbow, and wrist/hand were generally the most commonly injured anatomical locations; strains, tendinitis, and sprains were the most common injury type. Very few significant differences in any of the injury outcomes were observed as a function of age, sex, competitive standard, or bodyweight class. Conclusion: While the majority of the research we reviewed utilized retrospective designs, the weight-training sports appear to have relatively low rates of injury compared with common team sports. Future weight-training sport injury epidemiology research needs to be improved, particularly in terms of the use of prospective designs, diagnosis of injury, and changes in risk exposure

Translation of the FMR1 mRNA is not influenced by AGG interruptions

The fragile X mental retardation 1 (FMR1) gene contains a CGG-repeat element within its 5′ untranslated region (5′UTR) which, for alleles with more than ∼40 repeats, increasingly affects both transcription (up-regulation) and translation (inhibition) of the repeat-containing RNA with increasing CGG-repeat length. Translational inhibition is thought to be due to impaired ribosomal scanning through the CGG-repeat region, which is postulated to form highly stable secondary/tertiary structure. One striking difference between alleles in the premutation range (55–200 CGG repeats) and those in the normal range (<∼40 repeats) is the reduced number/absence of ‘expansion stabilizing’ AGG interruptions in the larger alleles. Such interruptions, which generally occur every 9–11 repeats in normal alleles, are thought to disrupt the extended CGG-repeat hairpin structure, thus facilitating translational initiation. To test this hypothesis, we have measured the translational efficiency of CGG-repeat mRNAs with 0–2 AGG interruptions, both in vitro (rabbit reticulocyte lysates) and in cell culture (HEK-293 cells). We demonstrate that the AGG interruptions have no detectable influence on translational efficiency in either a cell-free system or cell culture, indicating that any AGG-repeat-induced alterations in secondary/tertiary structure, if present, do not involve the rate-limiting step(s) in translational initiation

A multiscale method for optimising surface topography in elastohydrodynamic lubrication (EHL) using metamodels

The frictional performance of a bearing is of significant interest in any mechanical system where there are lubricated surfaces under load and in relative motion. Surface topography plays a major role in determining the coefficient of friction for the bearing because the size of the fluid film and topography are of a comparable order. The problem of optimising topography for such a system is complicated by the separation in scales between the size of the lubricated domain and that of the topography, which is of at least one order of magnitude or more smaller. This paper introduces a multiscale method for optimising the small scale topography for improved frictional performance of the large scale bearing. The approach fully couples the elastohydrodynamic lubrication at both scales between pressure generated in the lubricant and deformation of the bounding surfaces. Homogenised small scale data is used to inform the large scale model and is represented using Moving Least Squares metamodels calibrated by cross validation. An optimal topography for a minimum coefficient of friction for the bearing is identified and comparisons made of local minima in the response, where very different topographies with similar frictional performance are observed. Comparisons of the optimal topography with the smooth surface model demonstrated the complexity of capturing the non-linear effect of topography and the necessity of the multiscale method in capturing this. Deviations from the smooth surface model were quantified by the metamodel coefficients and showed how topographies with a similar frictional performance have very different characteristics

lmmature forms, genitalia, and notes on the biology of Anelaphus albofasciatus Linnell. (Coleoptera: Cerambycidae)

Volume: 48Start Page: 21End Page: 2

Design and analysis of lid closure bolts for packages used to transport radioactive materials

The design criterion recommended by the U.S. Department of Energy for Category I radioactive packaging is found in Section III, Division 1, of the ASME Boiler and Pressure Vessel Code. This criterion provides material specifications and allowable stress limits for bolts used to secure lids of containment vessels. This paper describes the design requirements for Category I containment vessel lid closure bolts, and provides an example of a bolting stress analysis. The lid-closure bolting stress analysis compares calculations based on handbook formulas with an analysis performed with a finite-element computer code. The results show that the simple handbook calculations can be sufficiently accurate to evaluate the bolt stresses that occur in rotationally rigid lid flanges designed for metal-to-metal contact