Development of an Untargeted Gas Chromatography-Mass Spectrometry (GC/MS) Method for the Detection of Drugs in Wastewater

Monitoring current illicit drug trends and consumption rates of pharmaceuticals using a non-invasive collection technique is needed to address the present drug use and the growing drug epidemic. Reliance on self-reporting drug use surveys is not always a practical measure of illicit drug use. Wastewater analysis has been used globally as a targeted method for monitoring the consumption of specific illicit drugs. Current existing analytical techniques for wastewater analysis focus on the use of targeted liquid chromatography-mass spectrometry (LC-MS) based techniques. Few gas chromatography (GC) procedures exist for wastewater analysis, and those that do concentrate their methods on a single class of drugs operating their mass spectrometer (MS) in selective ion monitoring (SIM) mode. This study aims to develop an untargeted, underivatized, full scan gas chromatography-mass spectrometry (GC/MS) method for the analysis of wastewater. Solid phase extraction (SPE) was performed with UCT mixed mode, 15 mL Clean Screen DAU columns with 500 mg sorbent to extract a 500 mL wastewater sample. Sample extracts were reconstituted in ethyl acetate and analyzed on a Shimadzu GCMS-QP2020 gas chromatograph-mass spectrometer (GC/MS) installed with an Agilent J&W HP-5MS (30 m × 0.25mm, 0.25 µm) column. Injection volume, flow rate, oven temperature, and ion source scan rate were optimized to develop an untargeted full scan method for the detection of pharmaceuticals. Calibration curves were developed for 42 targeted drugs. A 1 µL sample volume is run with a splitless injection utilizing helium as the carrier gas and the instrument operated in constant flow mode at a rate of 1.0 mL/min. The GC oven program is held at the initial temperature of 70°C for 2 min then ramped at 15°C/min to 300°C and held for 10 min for a total run time of 27.33 min. The injection port, transfer line, and source were set at 250°C, 280°C, and 200°C respectively. The MS operated in full scan mode, scanning ions from 35-550 m/z at an event time of 0.20 seconds from 3.50-27.33 minutes. Out of a 42 drug panel, over 75% of the generated calibration curves were suitable for quantitation with coefficients of determination greater than 0.9875. Limits of detection for most drugs ranged from 0.10-1.0 ng/mL, on par with many targeted liquid chromatography methods. The optimized untargeted method is able to detect a wide range of compounds in addition to those in the drug panel. The untargeted full scan MS method supports monitoring a wider range of pharmaceuticals overlooked in traditional targeted waste water methods such as changing trends in novel psychoactive substances

Identifying Bearing Rotordynamic Coefficients using an Extended Kalman Filter

An Extended Kalman Filter is developed to estimate the linearized direct and indirect stiffness and damping force coefficients for bearings in rotor-dynamic applications from noisy measurements of the shaft displacement in response to imbalance and impact excitation. The bearing properties are modeled as stochastic random variables using a Gauss-Markov model. Noise terms are introduced into the system model to account for all of the estimation error, including modeling errors and uncertainties and the propagation of measurement errors into the parameter estimates. The system model contains two user-defined parameters that can be tuned to improve the filter s performance; these parameters correspond to the covariance of the system and measurement noise variables. The filter is also strongly influenced by the initial values of the states and the error covariance matrix. The filter is demonstrated using numerically simulated data for a rotor-bearing system with two identical bearings, which reduces the number of unknown linear dynamic coefficients to eight. The filter estimates for the direct damping coefficients and all four stiffness coefficients correlated well with actual values, whereas the estimates for the cross-coupled damping coefficients were the least accurate

Photogrammetry System and Method for Determining Relative Motion Between Two Bodies

A photogrammetry system and method provide for determining the relative position between two objects. The system utilizes one or more imaging devices, such as high speed cameras, that are mounted on a first body, and three or more photogrammetry targets of a known location on a second body. The system and method can be utilized with cameras having fish-eye, hyperbolic, omnidirectional, or other lenses. The system and method do not require overlapping fields-of-view if two or more cameras are utilized. The system and method derive relative orientation by equally weighting information from an arbitrary number of heterogeneous cameras, all with non-overlapping fields-of-view. Furthermore, the system can make the measurements with arbitrary wide-angle lenses on the cameras

Activation of the Listeria monocytogenes Virulence Program by a Reducing Environment.

Upon entry into the host cell cytosol, the facultative intracellular pathogen Listeria monocytogenes coordinates the expression of numerous essential virulence factors by allosteric binding of glutathione (GSH) to the Crp-Fnr family transcriptional regulator PrfA. Here, we report that robust virulence gene expression can be recapitulated by growing bacteria in a synthetic medium containing GSH or other chemical reducing agents. Bacteria grown under these conditions were 45-fold more virulent in an acute murine infection model and conferred greater immunity to a subsequent lethal challenge than bacteria grown in conventional media. During cultivation in vitro, PrfA activation was completely dependent on the intracellular levels of GSH, as a glutathione synthase mutant (ΔgshF) was activated by exogenous GSH but not reducing agents. PrfA activation was repressed in a synthetic medium supplemented with oligopeptides, but the repression was relieved by stimulation of the stringent response. These data suggest that cytosolic L. monocytogenes interprets a combination of metabolic and redox cues as a signal to initiate robust virulence gene expression in vivoIMPORTANCE Intracellular pathogens are responsible for much of the worldwide morbidity and mortality from infectious diseases. These pathogens have evolved various strategies to proliferate within individual cells of the host and avoid the host immune response. Through cellular invasion or the use of specialized secretion machinery, all intracellular pathogens must access the host cell cytosol to establish their replicative niches. Determining how these pathogens sense and respond to the intracellular compartment to establish a successful infection is critical to our basic understanding of the pathogenesis of each organism and for the rational design of therapeutic interventions. Listeria monocytogenes is a model intracellular pathogen with robust in vitro and in vivo infection models. Studies of the host-sensing and downstream signaling mechanisms evolved by L. monocytogenes often describe themes of pathogenesis that are broadly applicable to less tractable pathogens. Here, we describe how bacteria use external redox states as a cue to activate virulence

Behavioral Mapless Navigation Using Rings

This paper presents work on the development and implementation of a novel approach to robotic navigation. In this system, map-building and localization for obstacle avoidance are discarded in favor of moment-by-moment behavioral processing of the sonar sensor data. To accomplish this, we developed a network of behaviors that communicate through the passing of rings, data structures that are similar in form to the sonar data itself and express the decisions of each behavior. Through the use of these rings, behaviors can moderate each other, conflicting impulses can be mediated, and designers can easily connect modules to create complex emergent navigational techniques. We discuss the development of a number of these modules and their successful use as a navigation system in the Trinity omnidirectional robot

The role of seasonal migration in the near-total loss of caribou on south-central Canadian Arctic Islands

Extended: In 1980 the caribou (Rangifer tarandus) on Prince of Wales, Russell, and Somerset islands represented a healthy geographic population of an Arctic-island caribou ecotype on the southern tier of Canadian Arctic Islands. Those caribou exhibited complex patterns of seasonal range occupancy, involving annual seasonal migrations between and among the three islands and Boothia Peninsula (Miller et al., 1982, 2005; Miller, 1990). A large segment of the population migrated annually from the islands to Boothia Peninsula in early winter, wintered there, and then returned to the islands in the following late winter and spring. There is no evidence for large-scale emigration of caribou anywhere in the study area (Gunn et al., 2006). Caribou on Boothia Peninsula occur as two distinct ecotypes that are genetically different from the Arctic-island ecotype that occurred on Prince of Wales, Russell, and Somerset islands (e.g., Zittlau, 2004). Both the Boothia Peninsula ecotype and the Mainland ecotype calve mostly on northern Boothia Peninsula, northwest and northeast sections respectively (Gunn et al., 2000). After summering on the peninsula, most individuals of both ecotypes migrate south of the Boothia Isthmus onto adjacent mainland areas (Gunn et al., 2000). As a result, there were about the same number of caribou wintering on Boothia Peninsula when migrant caribou from Prince of Wales, Russell, and Somerset islands wintered there, as in summer when the migrant Arctic-island caribou had returned to Prince of Wales, Russell, and Somerset islands and the migrant Boothia Peninsula and Mainland caribou ecotypes had returned from their winter ranges farther south on the mainland to their calving areas and summer ranges on Boothia Peninsula. We treat both caribou ecotypes on Boothia Peninsula as just one geographic population for our assessment. The Arctic-island caribou ecotype on Prince of Wales, Russell, and Somerset islands declined about 98% from the estimated 5097 1+ yr-old caribou in 1980 to fewer than 100 1+ yr-old caribou in 1995 (Gunn & Decker, 1984; Miller, 1997; Gunn & Dragon, 1998; Gunn et al., 2006). This loss of caribou on those islands amounts to a near-total loss of a genetically distinctive group of Arctic-island caribou (e.g., Zittlau, 2004). In contrast, the estimated number of caribou in the geographic population on Boothia Peninsula appeared to increase by 1.4-fold from 4831 to 6658 1+ yr-old caribou between 1985 and 1995, although annual harvesting pressure was heavy. It was biologically impossible for the Boothia Peninsula geographic population at its 1985 estimated size to have persisted until 1995, let alone to have increased, under the estimated average annual harvest regime of 1100 1+ yr-old caribou • yr-1. There is no evidence that the Boothia Peninsula population was underestimated in 1985. It would have required a population in 1985 at least twice as great as the calculated estimate to sustain the estimated annual harvest between 1985 and 1995. An underestimate of such magnitude is too great to be probable. In our examination of the survey results, we could find no reason to question that the calculated population estimates were not reasonable approximations. The fixed-wing aerial surveys in 1980 (Gunn & Decker, 1984), 1985 (Gunn & Ashevak, 1990), and 1995 (Gunn & Dragon, 1998) were highly comparable, well designed and executed, using standard procedures for a fixed-width, strip-transect, systematic aerial survey of caribou. One of the two observers was the same experienced survey biologist in all 3 years, the second observer in 1980 was an experienced survey biologist and in 1985 and 1995 was an experienced Inuit hunter familiar with the area, and the pilot was the same on all surveys and had flown many systematic surveys of caribou on the Canadian Arctic Archipelago and mainland Canada. Helicopter searches of known caribou ranges on Prince of Wales, Russell, and Somerset islands that were carried out in late winter 1996 under ideal viewing conditions yielded only two caribou on Somerset Island and none on Prince of Wales Island or Russell Island (Miller, 1997). In 2004, a combination aerial and ground survey of caribou by the Nunavut Wildlife Service, using a helicopter and snowmobile-mounted Inuit observers, failed to find even one caribou or any recent sign of caribou on Prince of Wales and Somerset islands (Gunn et al., 2006). Gunn et al. (2006) found no evidence that an absolute shortage of forage, relative unavailability of forage due to extreme snow and ice conditions, intraspecific competition with muskoxen (Ovibos moschatus), large-scale emigration, widespread disease, or heavy parasite burdens played a major role in the near-total loss of caribou on Prince of Wales, Russell, and Somerset islands. They did, however, conclude that both wolf (Canis lupus) predation and hunting on Prince of Wales, Russell, and Somerset islands most likely contributed to and deepened the final stage of the decline. The role of annual seasonal migration between the islands and Boothia Peninsula was not considered by Gunn et al. (2006). Therefore, we investigated how annual seasonal migration of the Arctic-island caribou ecotype from Prince of Wales, Russell, and Somerset islands to Boothia Peninsula could have played the major role by providing a yearly ongoing supply of caribou “recruits” on Boothia Peninsula to buffer the heavy annual harvest of caribou there. We carried out a series of multiple analyses of required population structure, required proportion of females producing calves, required proportion of calves surviving to yearlings, allowable annual harvest, and resultant annual harvest shortfall (the number of caribou lost annually at the estimated level of annual harvest or the number of additional caribou required annually from beyond Boothia Peninsula to sustain the annual harvest) in relation to the required size of the 1985 caribou population on Boothia Peninsula. We derived the annual harvest estimates from data presented in Gunn et al. (1986) and Jingfors (1986), which yielded a per capita mean annual harvest of 3.1 caribou • person-1 • yr-1 throughout the Kitikmeot region and at Taloyoak. We believe the extrapolated annual harvest estimates are conservative, as we did not inflate them to account for the 1.6-fold increase in the human population at Taloyoak between 1980 and 1995 and the Inuit hunters did not report any lack of caribou or hardships in obtaining them during that time. Inuit hunters prefer the meat of Arctic-island caribou to that of either the Boothia Peninsula ecotype or the Mainland ecotype. Thus, individuals of the Arctic-island caribou ecotype were shot each winter while they wintered on Boothia Peninsula in preference to both the Boothia Peninsula and the Mainland caribou ecotypes. Although caribou are killed year-round and there is no restriction on how many can be killed, most caribou hunting takes place during winter, when hunters can travel longer distances and haul carcasses back to the settlements more easily by snow machines. Our analyses and assessment of the changes over time in the sizes of the two caribou populations under consideration led us to three primary conclusions. 1) It was biologically impossible for the 4831 1+ yr-old caribou estimated on Boothia Peninsula in 1985 to have sustained the estimated average annual harvest of 1100 1+ yr-old animals for 10 years: the caribou population on the Boothia Peninsula would have been in a steady state of decline and, with the population performing at expected levels, would have been reduced to a remnant or even extirpated as early as 1992. 2) Although the estimated harvest level was unsustainable by the Boothia Peninsula population, the decline was masked by an annual winter infusion of the migrant Arctic-island caribou ecotype from Prince of Wales, Somerset and Russell islands onto Boothia Peninsula during the peak annual hunting period: without the infusion of caribou from the islands, the Inuit of Taloyoak could only have realized, on average, about two-fifths of the estimated annual harvests between 1985 and 1995 without the Boothia Peninsula population entering into a steady state of decline. 3) Migrant Arctic-island caribou from Prince of Wales, Russell, and Somerset islands wintered each year on Boothia Peninsula and this resulted in the persistence of caribou on the Boothia Peninsula, but led to the simultaneous near-demise of the caribou in the Prince of Wales, Russell, and Somerset islands geographic population. The caribou resource within the entire Prince of Wales-Russell-Somerset islands-Boothia Peninsula complex must be managed as a single unit. Effective management is not possible without ongoing assessment of the annual harvest combined with periodic monitoring of population size being carried out on all of those three islands and on Boothia Peninsula at the same times. To date this has not happened. A serious effort should be made to obtain annual harvest statistics yearly and population estimates every 3 years. The interval between population surveys could be stretched to 5 years if the budget demands it, but 6-10 years or more between surveys should be viewed as totally unacceptable. All population surveys should be carried out in July, to obtain population estimate and sex and age composition of the population at the same time during each year and long enough after June calving to get a good measure of the early survival of calves. If any evidence is obtained for large-scale ingress or egress, the population should be surveyed the following July and the magnitude and direction of population change determined and evaluated in relation to current annual harvest estimates. The population should be surveyed the following July after every exceptionally severe winter when a major die-off is probable due to extremely unfavorable snow and ice conditions. All responsible parties (renewable resource agencies and Inuit users) must have the will to act on the findings obtained from the monitoring efforts. Most importantly, they must take the necessary actions in a timely manner, if the findings indicate that the Boothia Peninsula caribou population is in a state of decline. Setting hunting regulations and enforcing harvest limits that are not agreed to by the Inuit users is not practical; therefore, only self-restraint by Inuit hunters will safeguard this valuable renewable caribou resource. The conservation of this hunted caribou population is complicated because preserving only a relatively few caribou is not a satisfactory goal. There must be enough caribou in the population to sustain the desired level of annual harvest or the annual harvest must be quickly adjusted downward to the sustainable level. Otherwise, with a steadily growing human population at Taloyoak, the future of the geographic population of caribou on Boothia Peninsula is not promising and most likely its continual use as a valuable renewable resource is in jeopardy. For further details on this subject see Miller et al. (2007)

St. Matthew Island reindeer crash revisited: Their demise was not nigh—but then, why did they die?

Twenty-nine yearling reindeer (Rangifer tarandus) were released on St. Matthew Island in the Bering Sea Wildlife Refuge in 1944: 24 females and five males. They were reported to have increased to 1350 reindeer by summer 1957 and to 6000 by summer 1963. The 6000 reindeer on St. Matthew Island in summer 1963 were then reduced by 99% to 42 by summer 1966. The evidence suggests that after growing at a high average annual rate of lamda = 1.32 for 19 years, the entire die-off occurred in winter 1963—64, making it the largest single-year crash ever recorded in any R. tarandus population. Although a supposedly meaningful decline in successful reproduction and early survival of calves was originally reported for the population between 1957 and 1963, our reevaluation indicates this is an error resulting from the wrong sample being used in the between-year comparison. The quantitative data indicate no meaningful change occurred, and the calf:cow ratio was about 60 calves:100 cows in both 1957 and 1963. Calf production and survival were high up to the crash, and in the die-off population the age distribution (72%, 1—3 years old) and the sex ratio (69 males:100 females) reflected a still fast-growing R. tarandus population. All of these parameters do not support the hypothesis that the limited abundance of the absolute food supply was at a lethal level between 1957 and 1963 or in winter 1963—64. We now know from other studies that a high density of R. tarandus is not a prerequisite for a major single-year winter die-off. Existing population dynamics data do not support lack of lichens as a major causative factor in this single-year crash. If a decline had been caused by the limitation of the absolute food supply, it would have followed a multi-year pattern—it would not have been a single-year event. There was no evidence of a sudden, massive, island-wide loss of the absolute food supply, or that its nutritional value was inadequate for sustaining the reindeer. Mean weights of reindeer by sex and age class declined between 1957 and 1963, but only to levels similar to those of mainland reindeer. The reindeer population on St. Matthew Island undoubtedly was or soon would have been seriously influenced by heavy use of the lichens and the future did not bode well for continued population growth. Although the food supply through interaction with climatic factors was proposed as the dominant population-regulating mechanism, a general acceptance that only density-dependent food-limitation was necessary to cause the crash remains strong in some quarters. We challenge this; we believe that the winter weather was the all-important factor that led to the premature, extreme, and exceptionally rapid, near total single-year loss of 99% of the reindeer on St. Matthew Island in winter 1963—64

Conservation of Peary caribou based on a recalculation of the 1961 aerial survey on the Queen Elizabeth Islands, Arctic Canada

The estimate of 25 845 Peary caribou (Rangifer tarandus pearyi) on the Queen Elizabeth Islands (QEI) in the Canadian High Arctic in summer 1961 is the only nearly range-wide 'benchmark' for the past number of caribou. No variances or confidence intervals were calculated for this estimate and no estimates were calculated for Peary caribou on the three major islands of Ellesmere, Devon, and Axel Heiberg. We reexamined the 1961 raw data by grouping the QEI into five island-complexes ('eco-units') and calculating, for each unit, the estimated number of caribou and the standard error, and the 95% confidence interval of the estimate, using a 'bootstrap' technique with 100 000 replications. Our goal was to provide an ecological basis for evaluating subsequent changes in numbers rather than relying on single-island evaluations. Our bootstrap reanalysis produced an estimate of 28 288 ± 2205 SE with a 95% CI of 20 436—37 031 Peary caribou on the QEI in summer 1961. Substantial differences in density were apparent among the five eco-units, with about a 50-fold difference from 0.01 caribou • km-2 in the Eastern eco-unit to 0.5 caribou • km-2 in the Northwestern eco-unit. The 1961 findings, with our subsequent reexamination, are crucial to any evaluation of trends for the number of Peary caribou on the QEI and the relative importance of individual eco-units for these animals. These findings also allow a more accurate evaluation of the magnitude of the subsequent decline of Peary caribou on the QEI during the last four decades and may help predict future potential levels for caribou in each of the five eco-units

Near-Total Loss of Caribou on South-Central Canadian Arctic Islands and the Role of Seasonal Migration in their Demise

Caribou (Rangifer tarandus) on the south-central Canadian Arctic Islands (Prince of Wales, Somerset, and Russell islands) declined by 98% sometime between 1980 and 1995—a near-total loss of a known genetically distinctive group of Arctic Island caribou. In contrast, caribou on the adjacent Boothia Peninsula seemingly increased by 38% from 1985 to 1995, while experiencing heavy annual hunting pressure. Our evaluation leads us to three primary conclusions. 1) It would have been biologically impossible for the estimated 1985 population on Boothia Peninsula (4831 ± 543 SE caribou one year old or older) to sustain the estimated annual harvest of 1100 one year old or older animals without continual annual ingress of caribou from beyond Boothia Peninsula. Our analysis of the 540 possible combinations of population parameters indicates that at any size within ± 2 SE of the 1985 estimate (3745–5917 caribou one year old or older), the Boothia Peninsula caribou population would have gone to “mathematical extirpation”: 99% of the combinations by 1995 and 100% by 1999. 2) The continued unsustainable level of harvest was masked by the annual winter infusion of migrant caribou onto Boothia Peninsula from Prince of Wales, Somerset, and Russell islands. 3) Caribou persisted on Boothia Peninsula, but only because of the simultaneous near elimination of the Arctic Island caribou ecotype in the Prince of Wales, Somerset, and Russell islands geographic population. This caribou resource cannot be properly conserved without adequate monitoring and periodic estimates of population sizes and annual harvest rates throughout the entire Prince of Wales, Somerset, and Russell islands-Boothia Peninsula complex.Entre 1980 et 1995, le nombre de caribous (Rangifer tarandus) du centre-sud de l’archipel Arctique canadien (îles du Prince-de-Galles, Somerset et Russell) a chuté de 98 %, ce qui représente la perte quasi totale d’un groupe génétiquement distinct de caribou de l’archipel Arctique. Par contre, il semblerait qu’entre 1985 et 1995, le caribou de la péninsule de Booth s’est accru de 38 %, malgré l’énorme pression exercée par la chasse tous les ans. Trois conclusions dérivent de notre évaluation. 1) Du point de vue biologique, il aurait été impossible pour la population estimée de la péninsule de Booth en 1985 (4 831 ± 543 (écart type) caribous d’un an ou plus) de soutenir la récolte annuelle estimée de 1 100 bêtes d’un an ou plus sans apport annuel continuel de caribous provenant d’ailleurs que la péninsule de Booth. Notre analyse des 540 combinaisons possibles de paramètres de population laisse croire que tout écart de ± 2 de l’écart-type des estimations de 1985 (3745–5917 caribous d’un an ou plus) de la population de caribous de la péninsule de Booth aurait fait l’objet d’une « extirpation mathématique » : 99 % des combinaisons vers 1995 et 100 % vers 1999. 2) Le taux continuellement insoutenable de récolte était masqué par l’infusion hivernale annuelle de caribous en migration sur la péninsule de Booth provenant des îles du Prince-de-Galles, Somerset et Russell. 3) Le caribou a persisté sur la péninsule de Booth, mais seulement en raison de la quasi-élimination simultanée de l’écotype du caribou de l’archipel arctique en ce qui a trait à la population géographique des îles du Prince-de-Galles, Somerset et Russell. Cette ressource en caribou ne peut être bien conservée sans la surveillance adéquate et l’estimation périodique de l’effectif de la population et des taux de récolte annuels à l’échelle de tout le complexe des îles du Prince-de-Galles, Somerset et Russell ainsi que de la péninsule de Booth

3D-XY critical fluctuations of the thermal expansivity in detwinned YBa2Cu3O7-d single crystals near optimal doping

The strong coupling of superconductivity to the orthorhombic distortion in YBa2Cu3O7-d makes possible an analysis of the superconducting fluctuations without the necessity of subtracting any background. The present high-resolution capacitance dilatometry data unambiguously demonstrate the existence of critical, instead of Gaussian, fluctuations over a wide temperature region (+/- 10 K) around Tc. The values of the amplitude ratio A+/A-=0.9-1.1 and the leading scaling exponent |alpha|<0.018, determined via a least-squares fit of the data, are consistent with the 3D-XY universality class. Small deviations from pure 3D-XY behavior are discussed.Comment: 11 pages including three figure