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Rattlesnake envenomation may lead to a multitude of clinical effects, including a late onset hemorrhage. Laboratory values such as platelets and fibrinogen are commonly used to assess the risk of developing a life-threatening bleed. To date, no specific threshold has been identified that links a lab value to the risk of bleeding. This has led to widespread practice variability among clinicians managing snake bites. In assessing risk for patients, we apply the concept that the more abnormal the lab values are, the higher the risk probably is. Late onset coagulopathies pose a unique clinical challenge because they indicate the potential risk for a life-threatening hemorrhage, yet they have been identified after hospital discharge. There are currently two antivenom (AV) products on the US market to treat rattlesnake envenomations, a Fab product, CroFab® (BTG, UK) and a F (ab')This study intended to characterize the incidence and severity of late coagulopathies reported to a Regional Poison Center (RPC) and hypothesized that late coagulopathies occur at rates higher than previously reported in the literature. Additionally, we sought to compare rates of late coagulopathy between Fab and F (ab')The investigators performed an in-depth review of all suspected snakebite envenomations from 2018 to 2020 that presented to an Arizona healthcare facility in the RPC's catchment area between January 2018 through December of 2020. Patients were excluded from analysis if they did not receive any antivenom, had an incomplete medical record with the APDIC, were diagnosed as something other than a rattlesnake bite or had a known medical history that clouded the diagnosis or assessment of a rattlesnake envenomation.In total, 522 records were reviewed of which 283 patients met the inclusion criteria. There were 149 patients who received Fab AV and 134 who received F (ab')The results from this study suggest the total rate of late onset coagulopathies may be underestimated. Additionally, our results suggest the potential that F (ab')

Social isolation and loneliness can create negative health outcomes for older adults. Informed by social capital and intergroup contact theories, our goal was to reduce these social problems using an intergenerational reverse-mentoring program. During fall 2020, we implemented an adapted, fully online version of Cyber-Seniors that encouraged undergraduate students to provide technology mentoring to local older adults in a seven-county area in rural Appalachia. We recruited gerontology students through the university and local older adults through local aging organizations. We collected data through pre-and post-tests that included validated measures (Lubben Social Network Scale-6 and UCLA 3-item loneliness scale) and open-ended questions about the program. Thirty-one students and nine older adults completed the pre-survey; twenty students and eight older adults completed the post-survey. We made comparisons using t-tests and considered p < 0.20 to indicate meaningful differences given the anticipated small sample size in this pilot project. Isolation did not change among older adults but increased among students in the family domain (p = 0.14) between baseline and follow-up. Loneliness improved between the pre- and post-tests among older adults (mean: 5.6 (SD = 2.2) to 4.1 (SD = 1.3), p = 0.17) but not among students (mean: 5.0 (SD = 1.5) to 5.2 (SD = 1.7), p = 0.73). In open-ended responses, older adults described learning new ways to interact with friends and family as a result of the program. This program was acceptable and suggested effectiveness in an important health-related domain (loneliness). While larger studies are needed to fully test the program’s impact, this pilot evaluation suggests that reverse mentoring programs can be implemented virtually and may improve social outcomes.

We developed and characterized a next-generation sequencing (NGS) technology for streamlined analysis of DNA and RNA using low-input, low-quality cancer specimens. A single-workflow, targeted NGS panel for non–small cell lung cancer (NSCLC) was designed covering 135 RNA and 55 DNA disease-relevant targets. This multiomic panel was used to assess 219 formalin-fixed paraffin-embedded NSCLC surgical resections and core needle biopsies. Mutations and expression phenotypes were identified consistent with previous large-scale genomic studies, including mutually exclusive DNA and RNA oncogenic driver events. Evaluation of a second cohort of low cell count fine-needle aspirate smears from the BATTLE-2 trial yielded 97% agreement with an independent, validated NGS panel that was used with matched surgical specimens. Collectively, our data indicate that broad, clinically actionable insights that previously required independent assays, workflows, and analyses to assess both DNA and RNA can be conjoined in a first-tier, highly multiplexed NGS test, thereby providing faster, simpler, and more economical results.

Lung cancer accounts for approximately 14% of all newly diagnosed cancers and is the leading cause of cancer-related deaths. Chimeric RNA resulting from gene fusions (RNA fusions) and other RNA splicing errors are driver events and clinically addressable targets for non-small cell lung cancer (NSCLC). The reliable assessment of these RNA markers by next-generation sequencing requires integrated reagents, protocols, and interpretive software that can harmonize procedures and ensure consistent results across laboratories. We describe the development and verification of a system for targeted RNA sequencing for the analysis of challenging, low-input solid tumor biopsies that includes reagents for nucleic acid quantification and library preparation, run controls, and companion bioinformatics software. Assay development reconciled sequence discrepancies in public databases, created predictive formalin-fixed, paraffin-embedded RNA qualification metrics, and eliminated read misidentification attributable to index hopping events on the next-generation sequencing flow cell. The optimized and standardized system was analytically verified internally and in a multiphase study conducted at five independent laboratories. The results show accurate, reproducible, and sensitive detection of RNA fusions, alternative splicing events, and other expression markers of NSCLC. This comprehensive approach, combining sample quantification, quality control, library preparation, and interpretive bioinformatics software, may accelerate the routine implementation of targeted RNA sequencing of formalin-fixed, paraffin-embedded samples relevant to NSCLC.

Snakebite severity corresponds to size of snake because the amount of venom a snake injects is positively associated with snake size. Because fang marks are often present on snakebite patients, we tested whether the relationship between snake length and distance between fang puncture wounds can be generalized for rattlesnakes of genus Crotalus.We measured 2 interfang distances from 79 rattlesnakes of both sexes, 5 species, and varying body length: 1) distance between fang bases in anesthetized snakes, and 2) distance between fang punctures in a membrane-covered beaker bitten defensively.Statistical analyses supported our 2 hypotheses, that 1) body size-related fang divergence during fang protraction (ie, anterolateral movement during fang erection), and 2) the relationship between snake length and interfang distance are similar between the sexes and among different rattlesnake species. We therefore derived a general equation to estimate snake length based on distance between fang marks, and recommended 5 snake size categories: very small (10 mm), small (10-15 mm), medium (15-20 mm), large (20-25 mm), and very large (25 mm).The distance between fang marks on a snakebite patient may be used to estimate the size or size category of the offending snake, which in some cases may have predictive value for overall clinical severity of a given envenomation. Assessing interfang distance from puncture wounds can improve snakebite research and anticipation of snakebite severity.

Artículo 10 páginas, 3 figuras 1 tabla, Understanding the origin and maintenance of phenotypic variation, particularly across a continuous spatial distribution, represents a key challenge in evolutionary biology. For this, animal venoms represent ideal study systems: they are complex, variable, yet easily quantifiable molecular phenotypes with a clear function. Rattlesnakes display tremendous variation in their venom composition, mostly through strongly dichotomous venom strategies, which may even coexist within a single species. Here, through dense, widespread population-level sampling of the Mojave rattlesnake, Crotalus scutulatus, we show that genomic structural variation at multiple loci underlies extreme geographical variation in venom composition, which is maintained despite extensive gene flow. Unexpectedly, neither diet composition nor neutral population structure explain venom variation. Instead, venom divergence is strongly correlated with environmental conditions. Individual toxin genes correlate with distinct environmental factors, suggesting that different selective pressures can act on individual loci independently of their co-expression patterns or genomic proximity. Our results challenge common assumptions about diet composition as the key selective driver of snake venom evolution and emphasize how the interplay between genomic architecture and local-scale spatial heterogeneity in selective pressures may facilitate the retention of adaptive functional polymorphisms across a continuous space., Funding: Leverhulme Trust Grant RPG 2013-315 to WW, Santander Early Career Research Scholarship to GZ, Ministerio de Economía y Competitividad Grant BFU2013-42833-P to JJC.

MicroLink Devices has developed a solar sheet technology with very high specific power for specific use on solar aircraft. These solar sheets have specific powers in excess of 1500 W/kg (AM0) which is an enabling technology for solarpowered unmanned aircraft that require maximum power generation in a format of minimum weight. This was achieved by maximizing the solar power generated by the solar sheet and minimizing the weight of the solar cells and packaging.

MicroLink Devices has developed two-terminal monolithic three-junction (3J) GaInP/GaAs/GaInAs epitaxial liftoff (ELO) solar cells with certified 37.75 ± 0.53% AM1.5G 1-Sun power conversion efficiency at 25°C. Additionally, MicroLink is developing two-terminal monolithic four-junction (4J) ELO solar cells based on GaInP/GaAs/GaInAs/GaInAs subcells with a peak preliminary AM0 1-Sun efficiency of 34.31%. All of these ELO solar cells were manufactured entirely with production tools and processes on reusable 150 mm diameter GaAs substrates.

MicroLink Devices has developed flexible, lightweight, high efficiency III-V inverted metamorphic multi-junction (IMM) solar cells that are attractive for mobile, terrestrial, airborne, and space applications. The solar cells are detached from their 6-inch diameter GaAs growth substrates using the epitaxial lift-off (ELO) technique, making the cells flexible and lightweight, and enabling reuse of the growth substrate. MicroLink’s ELO triple-junction solar cells have achieved NREL-certified 37.75% AM1.5G 1-Sun power conversion efficiency.

MicroLink Devices has developed triple-junction (3J) GaInP/GaAs/GaInAs epitaxial lift-off (ELO) 20 cm2 solar cells achieving >3 kW/kg specific power and >30% AMO (>34% AM1.5G) 1-Sun power conversion efficiency. These cells were manufactured using volume mass-production tools and processes. Preliminary reliability testing of bare cells and laminated arrays showed no appreciable degradation.

A prominent feature of gliding flight in snakes of the genus Chrysopelea is the unique cross-sectional shape of the body, which acts as the lifting surface in the absence of wings. When gliding, the flying snake Chrysopelea paradisi morphs its circular cross-section into a triangular shape by splaying its ribs and flattening its body in the dorsoventral axis, forming a geometry with fore–aft symmetry and a thick profile. Here, we aimed to understand the aerodynamic properties of the snake's cross-sectional shape to determine its contribution to gliding at low Reynolds numbers. We used a straight physical model in a water tunnel to isolate the effects of 2D shape, analogously to studying the profile of an airfoil of a more typical flyer. Force measurements and time-resolved (TR) digital particle image velocimetry (DPIV) were used to determine lift and drag coefficients, wake dynamics and vortex-shedding characteristics of the shape across a behaviorally relevant range of Reynolds numbers and angles of attack. The snake's cross-sectional shape produced a maximum lift coefficient of 1.9 and maximum lift-to-drag ratio of 2.7, maintained increases in lift up to 35 deg, and exhibited two distinctly different vortex-shedding modes. Within the measured Reynolds number regime (Re=3000–15,000), this geometry generated significantly larger maximum lift coefficients than many other shapes including bluff bodies, thick airfoils, symmetric airfoils and circular arc airfoils. In addition, the snake's shape exhibited a gentle stall region that maintained relatively high lift production even up to the highest angle of attack tested (60 deg). Overall, the cross-sectional geometry of the flying snake demonstrated robust aerodynamic behavior by maintaining significant lift production and near-maximum lift-to-drag ratios over a wide range of parameters. These aerodynamic characteristics help to explain how the snake can glide at steep angles and over a wide range of angles of attack, but more complex models that account for 3D effects and the dynamic movements of aerial undulation are required to fully understand the gliding performance of flying snakes.

The original description of Crotalus scutulatus (Chordata: Reptilia: Squamata: Viperidae) was published in 1861 by Robert Kennicott, who did not identify a type specimen or a type locality. We review the history of specimens purported to be the type(s) and various designations of type locality. We provide evidence that ANSP 7069 (formerly one of two specimens of USNM 5027) is the holotype and that the appropriate type locality is Fort Buchanan, near present-day Sonoita, in Santa Cruz County, Arizona.

We have developed an InGaP solar cell structure capable of operating at 450°C under N 2 ambient. This structure has been annealed for over 70h without degradation in room temperature performance. This type of structure has applications in hybrid solar energy plants which combine photovoltaic and thermal collection systems to maximize overall conversion efficiency. We anticipate that this device will be able to achieve up to 17% efficiency at 400°C and 500x concentration based on simulations with incorporated optical and electrical high-temperature semiconductor parameters.

Efforts to develop engineered tendons and ligaments have focused on the use of a biomaterial scaffold and a stem cell source. However, the ideal scaffold microenvironment to promote stem cell differentiation and development of organized extracellular matrix is unknown. Through electrospinning, fibre scaffolds can be designed with tailorable architectures to mimic the intended tissue. In this study, the effects of fibre diameter and orientation were examined by electrospinning thin mats, consisting of small ( 2 µm) diameter fibres with either random or aligned fibre orientation. C3H10T1/2 model stem cells were cultured on the six different electrospun mats, as well as smooth spin-coated films, and the morphology, growth and expression of tendon/ligament genes were evaluated. The results demonstrated that fibre diameter affects cellular behaviour more significantly than fibre alignment. Initially, cell density was greater on the small fibre diameter mats, but similar cell densities were found on all mats after an additional week in culture. After 2 weeks, gene expression of collagen 1α1 and decorin was increased on all mats compared to films. Expression of the tendon/ligament transcription factor scleraxis was suppressed on all electrospun mats relative to spin-coated films, but expression on the large-diameter fibre mats was consistently greater than on the medium-diameter fibre mats. These results suggest that larger-diameter fibres (e.g. > 2 µm) may be more suitable for in vitro development of a tendon/ligament tissue. Copyright © 2012 John Wiley & Sons, Ltd.

The rapid and accurate recognition of dangerously venomous snakes following bites is crucial to making appropriate decisions regarding first aid, evacuation, and treatment. Past recommendations for identification of dangerous North American pit vipers have often required subjective determinations of head shape or relied on traits shared with some nondangerous species (elliptical pupils and undivided subcaudal scales). Heat-sensitive facial pits are diagnostic but require close examination of the dangerous head, and cephalic traits are useless when working with a decapitated carcass. Exclusive of cephalic traits, pit vipers north of Mexico can be recognized by the combination of keeled middorsal scales and undivided subcaudal scales. The order of colored rings is usually suggested to identify coral snakes in the United States, yet extension of the colored rings across the ventral scales must be added as an essential identifying factor to ensure elimination of all harmless look-alikes. A novel 3-step flow chart is presented that allows dangerous snakes in the United States and Canada to be recognized quickly and dependably without relying on cephalic traits. This process cannot be used in other countries, however, due to greater variability of these characteristics in snakes from other parts of the world. Finally, close examination of potentially venomous snakes is extraordinarily dangerous and steps to safeguard those making such observations are discussed.

The reproductive ecology of Mohave rattlesnakes Crotalus scutulatus was investigated in the western Mohave Desert using radiotelemetry from August 2001 to November 2004. This paper documents reproductive behavior across successive seasons in the context of seasonal timing, mean daily movement, home range, body temperature and relationship with abiotic factors such as time of day, temperature, precipitation, photoperiod and microhabitat. This population of C. scutulatus used a bimodal mating system, with reproductive behavior occurring in late summer/fall (21 August to 7 October), interrupted by 4 months of cold weather, and concluding in the spring (16 March to 16 May). Drought apparently curtailed courtship and copulation during the 2002 activity season, but the pregnancy rates in 2002 and 2003 were not significantly affected. Communal denning was not detected and there was no indication of seasonal migration. Autumnal and vernal movements appeared to be driven by reproductive effort, predominantly males engaged in prolonged mate searching. Sexual maturity was achieved at 2.0 years/600 mm snout–vent length (SVL) for females, and 1.5 years/400 mm SVL for males.

The U.S. Environmental Protection Agency’s (USEPA) current ambient water quality criteria (AWQC) for cyanide were developed in 1984. Since this time, additional research on cyanide toxicity and analytical chemistry has suggested that cyanide AWQC values need to be updated to reflect the current state-of-the-science and to ensure that the methods for implementing the cyanide AWQC reflect the bioavailable and toxic forms of cyanide. Therefore, the Water Environment Research Foundation (WERF) sponsored a reassessment of the AWQC for cyanide by initiating a thorough review of the current scientific literature on cyanide and conducting additional laboratory studies to further understand cyanide chemistry and toxicity. Consistent with the USEPA’s draft strategy for developing AWQC, this evaluation also considered whether the cyanide AWQC are protective of benthos, threatened and endangered (T&E) species, and aquatic-dependent wildlife. This reassessment of AWQC for cyanide resulted in proposed freshwater acute and chronic criteria of 23 and 4.8 µg CN/L, respectively, which are comparable to the current freshwater acute and chronic criteria of 22 and 5.2 µg CN/L (free cyanide). For saltwater organisms, the reassessment resulted in proposed acute and chronic criteria of 20 and 4.1 µg CN/L (free cyanide), respectively, compared to the current saltwater acute and chronic criteria which are both 1.0 µg CN/L. The difference in the current and proposed saltwater criteria values is attributed to recent cyanide toxicity testing with several crab species in the genus Cancer and the copepod Acartia tonsa, which suggests this genus is not as sensitive to cyanide as previous cyanide toxicity testing indicated. A sediment-based cyanide criterion does not appear warranted if it is assumed that benthic organisms are not inordinately more sensitive to cyanide than the water column organisms that drive the basis for the proposed freshwater and saltwater criteria (the available cyanide toxicity data do not suggest that they would be), and given that bioavailable forms of cyanide are not expected to accumulate appreciably in sediment. Cyanide should thus be effectively regulated based on water column-based criteria and concentrations. Based on a combination of available empirical and estimated cyanide toxicity values for T&E species, the proposed freshwater criteria appear to be protective

We attempted to determine how accurately members of the public can identify venomous snakes. Six different snakes indigenous to southern California were displayed in cages for 265 people to view at a street fair. These included 4 nonvenomous snakes and 2 venomous snakes. People were asked whether the snake was venomous and the name of the snake, if they knew it. Overall, people recognized whether a snake was venomous or nonvenomous 81% of the time. They were most accurate at identifying rattlesnakes as being venomous (95%) but incorrectly identified nonvenomous snakes as being venomous 25% of the time. Men were more accurate than women, and adults were more accurate than children. Subjects were less well able to identify the exact species of snakes. The results suggest that there may be no need to capture, kill, or bring a snake to the hospital for identification, at least in this geographic area.

To maintain acceptable turbine airfoil temperatures, film cooling is typically used whereby coolant, extracted from the compressor, is injected through component surfaces. In manufacturing a turbine, the first stage vanes are cast in either single airfoils or double airfoils. As the engine is assembled, these singlets or doublets are placed in a turbine disk in which there are inherent gaps between the airfoils. The turbine is designed to allow outflow of high-pressure coolant rather than hot gas ingestion. Moreover, it is quite possible that the singlets or doublets become misaligned during engine operation. It has also become of interest to the turbine community as to the effect of corrosion and deposition of particles on component heat transfer. This study uses a large-scale turbine vane in which the following two effects are investigated: the effect of a midpassage gap on endwall film cooling and the effect of roughness on endwall film cooling. The results indicate that the midpassage gap was found to have a significant effect on the coolant exiting from the combustor-turbine interface slot. When the gap is misaligned, the results indicate a severe reduction in the film-cooling effectiveness in the case where the pressure side endwall is below the endwall associated with the suction side of the adjacent vane.

Southern Pacific rattlesnake (Crotalus helleri ) venom is not 1 of the 4 venoms used to produce Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV). There is currently no published clinical experience regarding the efficacy of this new antivenom for confirmed C helleri envenomation, and animal data suggest greatly diminished efficacy. We assessed the efficacy of FabAV for patients with confirmed C helleri envenomation.We conducted a prospective observational study of 23 consecutive rattlesnake envenomations that were treated with FabAV at our center. Patients were excluded if the species of snake could not be confirmed, if FabAV antivenom was not given, or if Antivenin (Crotalidae) polyvalent (equine) was given. We collected serial physical examination and laboratory data over a 24-hour period to serially evaluate the severity score and performed follow-up to evaluate delayed reactions.There were 15 patients who received FabAV and had the species of rattlesnake confirmed (9 C helleri, 4 C scutulatus scutulatus, 1 C mitchellii pyrrhus, 1 C ruber ruber ). C helleri envenomations demonstrated similar improvement in serial snakebite severity scores to those of other species. Three patients treated with scheduled dosing had recurrence of progressive swelling (2 C helleri and 1 C mitchellii pyrrhus ) during the 24-hour study period.We observed similar improvement in FabAV-treated patients with C helleri envenomation compared with those of other species and conclude that this treatment in standard doses appears efficacious for bites by this species. Progressive swelling may recur despite scheduled dosing.

This study examined relationships between hazard quotients (HQ) and probabilistic estimates of aquatic ecological risk. Questions addressed included the magnitude at which an HQ equates to significant risk, and the factors influencing the HQ-risk relationship. The analysis was based upon predicted exposure concentrations (PEC) for copper, hypothetical predicted no effect concentrations (PNEC) distributions, and measured PNEC data for aquatic species acutely and chronically exposed to copper, ammonia, cadmium, cyanide, dieldrin, DDT, phenanthrene, silver. and zinc. The cumulative PNEC and PEC distributions differed in slopes and magnitudes. The relationship between HQ and probabilistic risk, both of which were computed using conventional techniques, depended on the slopes of the PNEC and PEC distributions. Hazard quotients equaling 1.0 affected ∼ 5% of the species because they were based on PNECs intended to protect 5% of the species. Hazard quotients greater than 1.0 depended on PNEC slope. For example, H...

From the Department of Surgery, Division of Emergency Medicine, University of Utah, Salt Lake City, UT (Drs Caravati, Fuller, Kanaan, Ray, and Stewart); Department of Surgery, Division of General Surgery, University of Utah, Salt Lake City, UT (Dr Russell); Department of Surgery, Division of Emergency Medicine, Stanford University School of Medicine, Stanford, CA (Dr Norris); Department of Biological Sciences, California State University, Sacramento, CA (Mr Cardwell); Department of Toxinology, Women’s and Children’s Hospital, North Adelaide, South Australia, Australia (Dr Weinstein); and the East Carolina University Brody School of Medicine, Greenville, NC (Dr Bush).

Part I of this series demonstrated the Near-IR (NIR) method of determining the heat-set temperature (HST) of carpet yarn on bobbins in the laboratory, using a remote fiber optic probe. Part II describes an at-line NIR technique to determine the HST of carpet yarn bobbins at three manufacturing sites. At-line NIR measurement of HST is expanded to evaluate the influence of machinery and yarn processing factors, environmental factors, and quality differences. Optimized Suessen and Superba HST at-line NIR calibrations are developed in the laboratory and successfully transferred and verified on the manufacturing floor. Very good agreement is obtained between the stated HSTS and NIR-determined HSTS for samples with a wide range of HSTS and routine production samples, which exhibit quality differences in manufacturing. The major influence on NIR-determined HST results is the temperature and %RH in the manufacturing area; the NIR calibration can be readily adjusted with a control bobbin to offset these environmental effects without loss of method accuracy. An analytical methodology is presented for developing and transfering (verifying and validating) NIR measurements from a laboratory to an at-line analysis in the manufacturing area. Operational concerns and other procedural details include sample matrix effects, data treatment, temperature and environmental impacts, instrument parameters, and details of the experimental process.

†Parametrix, 5808 Lake Washington Boulevard Northeast, Suite 200, Kirkland, Washington 98033, USA‡Shell Oil Products Company, 777 Walker Street, P.O. Box 2099, Houston Texas 77252, USA(Received 21 May 1999; Accepted 14 February 2000)Abstract—A site-specific marine water–quality criterion for cyanide was developed for Puget Sound, Washington, USA. The U.S.Environmental Protection Agency (U.S. EPA) national cyanide water-quality criterion is driven by toxicity data for the eastern rockcrab, Cancer irroratus, a species not resident to the U.S. western coast (West Coast). The reported LC50 forC. irroratus is sixtimes lower than any other marine species tested. Cyanide acute toxicity tests were conducted using first stage zoeae of all fourspecies of Cancer spp. resident to Puget Sound to develop a site-specific criterion for this water body. Testing with Puget SoundCancer spp. reveals sensitivities 24 times less, on average, than C. irroratus. Recalculation of the Puget Sound water-qualitycriterion for cyanide, by substituting the new Cancer spp. data for the C. irroratus data, results in water-quality criterion protectingmarine life against acute and chronic toxicity of 9.4 and 2.9 mg/L cyanide, compared to the U.S. EPA national value of 1.0mg/Lfor both acute and chronic toxicity.Keywords—Cyanide Site-specific criterion Cancer irroratus Puget SoundINTRODUCTION

Mojave rattlesnake (Crotalus scutulatus scutulatus) identification has important diagnostic and therapeutic implications. Envenomation by certain populations of Mojave rattlesnakes may cause a different clinical presentation than that caused by other rattlesnakes. Specifically, Mojave rattlesnake envenomation may cause fewer local effects and more neurologic effects (including respiratory difficulty) than are typically seen after bites from other types of rattlesnake. Thus, it is useful for clinicians to distinguish the Mojave rattlesnake from other rattlesnakes in order to prevent underestimation of severe envenomation because of the lack of local tissue injury. Patients suspected to have been bitten by Mojave rattlesnakes may need more aggressive treatment with antivenin as well as more intensive supportive care. In addition, patients suspected to have been bitten by Mojave rattlesnakes should be closely monitored for an extended observation period, as venom effects may be delayed or prolonged. Mojave rattlesnakes may be particularly difficult to distinguish from Western Diamondback rattlesnakes (Crotalus atrox) because of their similarity in appearance and overlapping ranges. The purpose of this report is to provide clinicians with key characteristics which may assist in distinguishing Mojave rattlesnakes from Western Diamondback and other rattlesnakes.

In this review, we sought to assess from a study of the literature whether five in organic metals (viz., cadmium, copper, lead, nickel, and zinc) bio magnify in aquatic food webs. We also examined whether accumulated metals were toxic to consumers/predators and whether the essential metals (Cu and Zn and possibly Ni) behaved differently from non-essential ones (Cd and Pb). Biomagnification potential was indexed by the magnitude of single and multiple trophic transfers in food chains. In this analysis, we used three lines of evidence-laboratory empirical, biokinetic modeling, and field studies-to make assessments. Trophic transfer factors, calculatedfrom lab studies, field studies, and biokinetic modeling, were generally congruent.Results indicated that Cd, Cu, Pb, and Zn generally do not biomagnify in food chains consisting of primary producers, macro invertebrate consumers, and fish occupying TL 3 and higher. However, bio magnification of Zn (TTFs of 1-2) is possible for circumstances in which dietary Zn concentrations are below those required for metabolism. Cd, Cu, Ni, and Zn may biomagnify in specific marine food chains consisting of bivalves, herbivorous gastropods, and barnacles at TL2 and carnivorous gastropods at TL3. There was an inverse relationship between TTF and exposure concentration for Cd, Cu, Pb, and Zn, a finding that is consistent with previous reviews of bioconcentration factors and bioaccumulation factors for metals. Our analysis also failed to demonstrate a relationship between the magnitude of TTFsand dietary toxicity to consumer organisms. Consequently, we conclude that TTFs for the metals examined are not an inherently useful predictor of potential hazard(i.e., toxic potential) to aquatic organisms. This review identified several uncertainties or data gaps, such as the relatively limited data available for nickel, reliance upon highly structured food chains in laboratory studies compared to the unstructured food webs found in nature, and variability in TTFs between the organisms found in different habitats, and years sampled.

Trophic transfer (biotransference—Dallinger et al. 1987) results from passage of a contaminant through food chains as a result of uptake only from water (bioconcentration), only from diet (dietary accumulation), or from a combination of these (bioaccumulation) (Biddinger and Gloss 1984; Davis and Foster 1958; Macek et al. 1979; Suedel et al. 1994). Trophic transfer factors (TTFs) are analogous to bioaccumulation (accumulation) factors, the original terms used to describe steady-state tissue residues in an organism resulting from both water and dietary uptake pathways (Boroughs et al. 1957). TTFs are the same as biomagnification factors and also meet the definition of biomagnification when TTFs exceeding 1.0 are observed through three or more trophic levels as a result of at least two trophic transfers (Biddinger and Gloss 1984). Most investigators have assumed TTFs result mainly from dietary accumulation (Baptist and Lewis 1967; Mathews and Fisher 2008; Reinfelder et al. 1998), although it is not possible to distinguish aqueous from dietary uptake in field studies. Moreover, the relative importance of the diet and aqueous uptake pathways is context-dependent, varying with exposure duration, metal bioavailability, and the species and their prey. Application of the aquatic TTF concept, as currently understood, may have first been proposed by Baptist and Lewis (1967), and the term had been widely adopted by the early 1990s (Baudin and Nucho 1992; Dillon et al. 1995; Garnier-Laplace et al. 1997; Suedel et al. 1994).

Efforts to develop engineered tendons and ligaments have focused on the use of a biomaterial scaffold and a stem cell source. However, the ideal scaffold microenvironment to promote stem cell differentiation and development of organized extracellular matrix is unknown. Through electrospinning, fibre scaffolds can be designed with tailorable architectures to mimic the intended tissue. In this study, the effects of fibre diameter and orientation were examined by electrospinning thin mats, consisting of small (1 µm), medium (1-2 µm) or large (2 µm) diameter fibres with either random or aligned fibre orientation. C3H10T1/2 model stem cells were cultured on the six different electrospun mats, as well as smooth spin-coated films, and the morphology, growth and expression of tendon/ligament genes were evaluated. The results demonstrated that fibre diameter affects cellular behaviour more significantly than fibre alignment. Initially, cell density was greater on the small fibre diameter mats, but similar cell densities were found on all mats after an additional week in culture. After 2 weeks, gene expression of collagen 1α1 and decorin was increased on all mats compared to films. Expression of the tendon/ligament transcription factor scleraxis was suppressed on all electrospun mats relative to spin-coated films, but expression on the large-diameter fibre mats was consistently greater than on the medium-diameter fibre mats. These results suggest that larger-diameter fibres (e.g.2 µm) may be more suitable for in vitro development of a tendon/ligament tissue.

The measurement of turbulent flows becomes problematic when considering a dispersed multiphase flow, which typically requires special techniques focusing on the simultaneous resolution of both the carrier and discrete phases present in the flowfield. The method presented in this paper, a multi-parametric particle pairing algorithm for particle tracking velocimetry (MP3-PTV), provides a powerful and flexible technique for the measurement of multiphase flows. Combined with a traditional Particle Image Velocimetry (PIV) system, the MP3-PTV employs a variable pair-matching algorithm which utilizes displacement preconditioning in combination with estimated particle size and intensity to match particle pairs between successive images. To improve the method’s efficiency, a new particle identification and segmentation routine was also developed. Validation of the new method was performed on two artificial data sets: a traditional single-phase flow published by the Visualization Society of Japan (VSJ) and an in-house generated multiphase flow having a bi-modal distribution of particles diameters. On the VSJ data set, the newly presented segmentation routine delivered a two-fold increase in identifying particles compared to other published methods. For the simulated multiphase flow data set, measurement efficiency of the dispersed phase improved from 9% to 41% for MP3-PTV as compared to traditional hybrid PTV.Copyright © 2011 by ASME

Screening of biomaterial and tissue systems in vitro, for guidance of performance in vivo, remains a major requirement in the field of tissue engineering. It is critical to understand how culture stimulation affects both tissue construct maturation and function, with the goal of eliminating resource-intensive trial-and-error screening and better matching specifications for various in vivo needs. In this article a multifunctional and robust bioreactor design that addresses this need is presented. The design enables a range of mechanical inputs, durations, and frequencies to be applied in coordination with noninvasive optical assessments. A variety of biomaterial systems, including micro- and nano-fiber and porous sponge biomaterials, as well as cell-laden tissue engineering constructs were used in validation studies to demonstrate the versatility and utility of this new bioreactor design. The silk-based biomaterials highlighted in these studies offered several unique optical signatures for use in label-free nondestructive imaging that allowed for sequential profiling. Both short- and long-term culture studies were conducted to evaluate several practical scenarios of usage: on a short-term basis, the authors demonstrate that construct cellularity can be monitored by usage of nonpermanent dyes; on a more long-term basis, the authors show that cell ingrowth can be monitored by green-fluorescent protein (GFP)-labeling, and construct integrity probed with concurrent load/displacement data. The ability to nondestructively track cells, biomaterials, and new matrix formation without harvesting designated samples at each time point will lead to less resource-intensive studies and should enhance our understanding and the discovery of biomaterial designs related to functional tissue engineering.

Gas turbines for aircraft are designed for operation with a clean inlet air flow. This ideal operational condition is often violated during take-off and landing, where the probability of particle ingestion is high, with sand and dirt being the most commonly observed foreign particles. Current research on particle ingestion has identified several mechanisms that contribute to performance degradation in the turbine: erosion of internal and external surfaces, and flow blockages of film-cooling holes and internal cooling passages. The focus of the study given in this paper is to present a method that identifies the motion of foreign particles within an internal ribbed passage. The method uses a high-resolution, flow field interrogation method known as time-resolved digital particle image velocimetry (TRDPIV). Observations from the two-phase flows showed that particle collisions occurred more frequently on the upstream surface of the ribs, especially in the inlet region. Results from these collisions included substantial particle breakup, and a particle rebounding phenomenon between the upper and lower walls. Comparisons are made to large eddy simulation predicted particle trajectories indicating some agreement, as well as phenomena that are not predicted due to the inherent assumption of the modeling.

Gas turbines are not generally designed for operation with a particle laden inlet flow but, in fact, are commonly operated in unclean environments resulting in dirt, sand, and other debris ingestion. In addition to the negative effects within the main gas path, for aeroengines these particles are pulled into the coolant system where they can clog cooling passages and erode internal surfaces. Unlike previous research that focused on deposition and erosion within the main gas path, this study evaluated blocking in a double wall liner whereby both impingement and film-cooling holes were simulated. Double wall liners are commonly used in the combustor and turbine for combined internal and external cooling of metal components. Specifically, sand blockages were evaluated through comparisons of measured flowrates for a particular pressure ratio across the liner. Four liner geometries were tested whereby the coolant hole size and orientation were varied in test coupons. At ambient temperature, blocking was shown to be a function of the impingement flow area. A significant rise in blocking was observed as sand and metal temperatures were increased. The overlap between the impingement and film-cooling holes was also found to have a significant effect.

Gas turbines for aircraft are designed for operation with a clean inlet air flow. This ideal operational condition is often violated during take-off and landing, where the probability of particle ingestion is high with sand and dirt being the most commonly observed foreign particles. Current research on particle ingestion has identified several mechanisms that contribute to performance degradation in the turbine: erosion of internal and external surfaces; and flow blockages of film-cooling holes and internal cooling passages. The focus of the study given in this paper is to present a method that identifies the motion of foreign particles within an internal ribbed passage. The method uses a high-resolution, flowfield interrogation method known as Time-Resolved Digital Particle Image Velocimetry (TRDPIV). Observations from the two-phase flows showed that particle collisions occurred more frequently on the upstream surface of the ribs, especially in the inlet region. Results from these collisions included substantial particle breakup and a particle rebounding phenomenon between the upper and lower walls. Comparisons are made to LES predicted particle trajectories indicating some agreement, but also phenomena that are not predicted due to the inherent assumption of the modeling.

Ambient concentrations of metals in surface waters have become an important consideration when establishing water quality criteria and conducting risk assessments. This study sought to estimate amounts of zinc that may be released into freshwater considering ambient concentrations, toxicity thresholds, and bioavailability. Cumulative distribution functions of ambient zinc concentrations were compared statistically for streams and lakes in Europe, North America, and South America to identify differences among mean distribution variables (e.g., slopes, intercepts, and inflection points). Results illustrated that most of the distributions among sites differed significantly. These differences illustrate the variability in ambient zinc concentrations in surface waters because of geographic location, regional geology, and anthropogenic influence. Additionally, water quality data were used to estimate bioavailable zinc concentrations in ambient surface waters (based on predictions using biotic ligand models). The amount of dissolved metal that could be added to surface waters without exceeding toxicity thresholds was calculated by subtracting ambient surface water concentrations from chronic no observable effect concentrations (NOEC; reproduction for Daphnia magna) or 10% effective concentrations (EC10; growth rate for Pseudokirchneriella subcapitata). Because ambient dissolved-zinc concentrations were, on average, below predicted effects thresholds, an average of 57.1 +/- 175 microg/L (+/- SD) of zinc could be added before exceeding the D. magna chronic NOEC or the P. subcapitata chronic EC10. However, numerous sites (17%) were identified as having ambient zinc concentrations in excess of these toxicity thresholds. This article uses existing biotic ligand models for zinc to estimate the potential magnitudes and variabilities of bioavailable zinc concentrations in fresh surface waters from different regions of the world.

Gas turbines are not generally designed for operation with a particle laden inlet flow but, in fact, are commonly operated in unclean environments resulting in dirt, sand, and other debris ingestion. In addition to the negative effects within the main gas path, for aeroengines these particles are pulled into the coolant system where they can clog cooling passages and erode internal surfaces. Unlike previous research that focused on deposition and erosion within the main gas path, this study evaluated blocking in a double wall liner whereby both impingement and film-cooling holes were simulated. Double wall liners are commonly used in the combustor and turbine for combined internal and external cooling of metal components. Specifically, sand blockages were evaluated through comparisons of measured flowrates for a particular pressure ratio across the liner. Four liner geometries were tested whereby the coolant hole size and orientation were varied in test coupons. At ambient temperature, blocking was shown to be a function of the impingement flow area. A significant rise in blocking was observed as sand and metal temperatures were increased. The overlap between the impingement and film-cooling holes was also found to have a significant effect.

Wall-mounted roughness features, such as ribs, are often placed along the walls of a channel to increase the convective surface area and to augment heat transfer and mixing by increasing turbulence. Depending on the relative roughness size and orientation, the ribs also have varying degrees of increased pressure losses. Designs that use ribs to promote heat transfer encompass the full range of having only a few streamwise ribs, which do not allow fully developed flow conditions, to multiple streamwise ribs, which do allow the flow to become fully developed. The majority of previous studies have focused on perturbing the geometry of the rib with little attention to the spatially and temporally varying flow characteristics and their dependence on the Reynolds number. A staggered rib-roughened channel study was performed using time-resolved digital particle image velocimetry (TRDPIV). Both the developing (entry region) and a fully developed region were interrogated for three Reynolds numbers of 2,500, 10,000, and 20,000. The results indicate that the flow was more sensitive to Reynolds number at the inlet than within the fully developed region. Despite having a similar mean-averaged flowfield structure over the full Reynolds number range investigated, the population and distribution of coherent structures and turbulent dissipation within the fully developed region were also found to be Reynolds number dependent. Exploring the time-accurate flow characteristics revealed that in addition to vortices shed from the rib shear layer, the region of the rib wake was governed by a periodic process of bursting of the wake vortices resulting in the intermittent ejection of the inter-rib recirculation region into the core flow. This periodic process was the driving mechanism resulting in mixing and heat transfer augmentation. A quadrant-splitting burst analysis was also performed to determine the characteristic frequency and duration of inter-rib bursting as well as the wake shedding frequency, both of which were determined to be Reynolds number dependent.

s Feature Editor: Steven A. Seifert, MD, FACMT, FACEP JOURNAL OF MEDICAL TOXICOLOGY ■ VOLUME 2, NUMBER 1 ■ MARCH 2006 29 From “Snakebites in the New Millennium: A State-of-the-Art Symposium” University of Nebraska Medical Center, October 21–23, 2005

To protect hot turbine components, cooler air is bled from the high pressure section of the compressor and routed around the combustor where it is then injected through the turbine surfaces. Some of this high pressure air also leaks through the mating gaps formed between assembled turbine components where these components experience expansions and contractions as the turbine goes through operational cycles. This study presents endwall adiabatic effectiveness levels measured using a scaled up, two-passage turbine vane cascade. The focus of this study is evaluating the effects of thermal expansion and contraction for the combustor-turbine interface. Increasing the mass flow rate for the slot leakage between the combustor and turbine showed increased local adiabatic effectiveness levels while increasing the momentum flux ratio for the slot leakage dictated the coverage area for the cooling. With the mass flow held constant, decreasing the combustor-turbine interface width caused an increase in uniformity of coolant exiting the slot, particularly across the pressure side endwall surface. Increasing the width of the interface had the opposite effect thereby reducing coolant coverage on the endwall surface.

To maintain acceptable turbine airfoil temperatures, film-cooling is typically used whereby coolant, extracted from the compressor, is injected through component surfaces. In manufacturing a turbine, the first stage vanes are cast in either single airfoils or double airfoils. As the engine is assembled, these singlets or doublets are placed in a turbine disk in which there are inherent gaps between the airfoils. The turbine is designed to allow outflow of high pressure coolant rather than hot gas ingestion. Moreover, it is quite possible that the singlets or doublets become misaligned during engine operation. It has also become of interest to the turbine community as to the effect of corrosion and deposition of particles on component heat transfer. This study uses a large scale turbine vane in which the following two effects are investigated: the effect of a mid-passage gap on endwall film-cooling and the effect of roughness on endwall film-cooling. The results indicate that the mid-passage gap was found to have a significant effect on the coolant exiting from the combustor-turbine interface slot. When the gap is misaligned, the results indicate a severe reduction in the film-cooling effectiveness in the case where the pressure side endwall is below the endwall associated with the suction side of the adjacent vane.

The purpose of this study was to develop a site-specific water quality standard for selenium in the Great Salt Lake, Utah, USA. The study examined the bioavailability and toxicity of selenium, as selenate, to biota resident to the Great Salt Lake and the potential for dietary selenium exposure to aquatic dependent birds that might consume resident biota. Because of its high salinity, the lake has limited biological diversity with bacteria, algae, diatoms, brine shrimp, and brine flies being the only organisms present in the main (hypersaline) portions of the lake. To evaluate their sensitivity to selenium, a series of acute and chronic toxicity studies were conducted on brine shrimp (Artemia franiciscana), brine fly (Ephydra cinerea), and a hypersaline alga (Dunaliella viridis). The resulting acute and chronic toxicity data indicated that resident species are more selenium tolerant than many freshwater species. Because sulfate is known to reduce selenate bioavailability, this selenium tolerance is thought to result in part from the lake's high ambient sulfate concentrations (5,800 mg/L). The acute and chronic test results were compared to selenium concentrations expected to occur in a mining effluent discharge located at the south end of the lake. Based on these comparisons, no appreciable risks to resident aquatic biota were projected. Field and laboratory data collected on selenium bioaccumulation in brine shrimp demonstrated a linear relationship between water and tissue selenium concentrations. Applying a dietary selenium threshold of 5 mg/kg dry weight for aquatic birds to this relationship resulted in an estimate of 27 microg/L Se in water as a safe concentration for this exposure pathway and an appropriate chronic site-specific water quality standard. Consequently, protection of aquatic birds represents the driving factor in determining a site-specific water quality standard for selenium.

Mojave toxin (MT) was detected in five of 25 Crotalus helleri (Southern Pacific rattlesnake) sampled using anti-MT antibodies and nucleotide sequence analysis. All of the venoms that were positive for MT were collected from Mt San Jacinto in Riverside Co., California. Since this population is geographically isolated from C. scutulatus scutulatus (Mojave rattlesnake), it is unlikely that this finding is due to recent hybridization. MT concentration differences between C. helleri and C. s. scutulatus reflected the presence of ‘isoforms’ of the toxin in the venom. Whereas C. s. scutulatus generally has several isoforms of the toxin (detected by Western blotting), only one ‘isoform’ that focused at pI 5.1 was detected in C. helleri. Both acidic and basic subunits of MT sequences were obtained from C. helleri DNA with primers specific for MT, but only from snakes that had MT in their venom. The sequence identity of the C. helleri acidic subunit to the C. s. scutulatus subunit was 84.9%, whereas the sequence identity of the C. helleri basic subunit was 97% to the C. s. scutulatus basic subunit. Using casein, fibrin, and hide powder azure as substrates, assays for proteolytic activity suggested that C. helleri possesses several different types of metalloproteinases in their venom. However, proteolytic activity was not detected, or present in reduced amounts, in specimens having MT. Clinical neurotoxicity following envenomation by certain populations of C. helleri may be due to MT.

We determined the chronic toxicity of arsenic (sodium arsenate) to the Great Salt Lake brine shrimp, Artemia franciscana. Chronic toxicity was determined by measuring the adverse effects of arsenic on brine shrimp growth, survival, and reproduction under intermittent flow-through conditions. The study commenced with