Search

AbstractBeaulieu J, Yates MC, Astorg L, Trépanier-Leroux D, Jeon H, Rudko SP, Humphries S, Fraser DJ, Cristescu ME, Derry AM. 2024. Environmental DNA for assessing impact and recovery of aquatic communities in an invaded mountain lake. Lake Reserv Manage. 40:111–131. The eradication of invasive species and associated side effects that influence the reestablishment of biological communities is a major challenge for conservation management of invaded ecosystems. We present a before-and-after-disturbance whole lake manipulation study from a high-elevation mountain lake in which we applied a 2-pronged approach to environmental DNA (eDNA) for assessing (1) impact and recovery of aquatic communities to the chemical eradication of invasive brook trout (Salvelinus fontinalis) and (2) the success of chemical eradication of the invasive fish. Using 18S and cytochrome oxidase I (COI) eDNA metabarcoding, we contribute to a paucity of literature that has comprehensively addressed nontarget effects of rotenone for invasive fish eradication on aquatic communities. We found that key trophic groups (phytoplankton, fungi, zooplankton, and macroinvertebrates) changed in community composition in response to rotenone applications. Fungi and macroinvertebrates, but not zooplankton and phytoplankton, reverted back toward pre-rotenone communities over the time scale of 2 yr. However, COI failed to detect several key species for food web reestablishment that were detected using physical specimen collection, likely due to low primer efficiency. We also found that quantitative polymerase chain reaction (qPCR), using species-specific primers, was effective for detecting brook trout presence/absence, although strong eDNA signals likely produced from carcasses in the ecosystem limited the utility of eDNA immediately following rotenone treatment. We provide specific recommendations for lake managers for the future application of eDNA approaches to monitor invasive fish eradication efforts and nontarget community effects for lake ecosystem restoration.

AbstractBeaulieu J, Trépanier-Leroux D, Fischer JM, Olson MH, Thibodeau S, Humphries S, Fraser DJ, Derry AM. 2021. Rotenone for exotic trout eradication: nontarget impacts on aquatic communities in a mountain lake. Lake Reserv Manage. 37:323–338.Rotenone is widely used in lake and reservoir management for the eradication of exotic fish. However, nontarget effects of rotenone on freshwater organisms such as zooplankton and macroinvertebrates are of concern because of the ecological importance of these organisms in aquatic food webs as a resource base for fish, especially when rotenone is applied to lakes prior to native fish reintroduction. The objective of our study was to determine the effects of rotenone on nontarget zooplankton and macroinvertebrate species assemblages in a headwater mountain lake where rotenone was applied to remove exotic brook trout (Salvelinus fontinalis; Banff, AB Canada). We found strong negative rotenone impacts on the community structure and density of crustacean zooplankton, and to a lesser extent on macroinvertebrates, lasting for at least 1 yr after the rotenone treatment. Our study offers 2 unique insights that differentiate from rotenone studies on other lakes: (1) the persistent and almost complete eradication of crustacean zooplankton in the following summers, 11 months after rotenone treatment, and (2) a considerable shift in the macroinvertebrate community composition, likely resulting from combined effects of both nontarget rotenone effects on taxon density and trophic interactions associated with the eradication of brook trout from the lake. We advocate that assisted recolonization in the restoration of aquatic food webs could play an important role in facilitating nontarget aquatic community recovery following lake rotenone treatment.

We conduct a novel comprehensive investigation that seeks to prove the connection between spatial scales and timescales in surface soil moisture (SM) within the satellite footprint (~50 km). Modeled and measured point series at Yanco and Little Washita in situ networks are first decomposed into anomalies at timescales ranging from 0.5 to 128 days, using wavelet transforms. Then, their degree of spatial representativeness is evaluated on a per‐timescale basis by comparison to large spatial scale data sets (the in situ spatial average, SMOS, AMSR2, and ECMWF). Four methods are used for this: temporal stability analysis (TStab), triple collocation (TC), percentage of correlated areas (CArea), and a new proposed approach that uses wavelet‐based correlations (WCor). We found that the mean of the spatial representativeness values tends to increase with the timescale but so does their dispersion. Locations exhibit poor spatial representativeness at scales below 4 days, while either very good or poor representativeness at seasonal scales. Regarding the methods, TStab cannot be applied to the anomaly series due to their multiple zero‐crossings, and TC is suitable for week and month scales but not for other scales where data set cross‐correlations are found low. In contrast, WCor and CArea give consistent results at all timescales. WCor is less sensitive to the spatial sampling density, so it is a robust method that can be applied to sparse networks (one station per footprint). These results are promising to improve the validation and downscaling of satellite SM series and the optimization of SM networks. The spatial representativeness of in situ stations tends to increase with the timescale within the satellite footprintStations poorly represent the satellite footprint at subweekly scales, while either very well or poorly at seasonal scalesThe wavelet correlation (WCor) method is a useful tool to study the spatial scale mismatch between in situ and satellite observations

Background:The minimal structural requirements of low‐molecular‐weight heparins that determine the risk of developing heparin‐induced thrombocytopenia (HIT) are not fully defined.Objectives:The ability of enoxaparin‐derived oligosaccharides (OS) to induce platelet activation and exposure of platelet‐factor 4 (PF4) epitopes recognized by antibodies developed in HIT was studied by surface plasmon resonance (SPR) and serotonin release assay.Results:Decasaccharides with ≥ 11 sulfate groups induced platelet activation in the presence of plasma from patients with confirmed HIT. Serotonin release of > 80% without full inhibition at 100 μg mL−1was achieved with decasaccharides containing 14 or 15 sulfate groups, 2 dodecasaccharides and 2 tetradecasaccharides. An SPR method was developed using purified PF4 immobilized on carboxymethylated dextran. Antibodies from all HIT samples bound to PF4/heparin in SPR assays with resonance units (RU) ratio of 109–173 with HIT plasma vs. 88–93 with control plasma. RU ratios > 100 were measured when PF4 was pre‐incubated with OS with ≥ 10 saccharide units and one octasaccharide containing 10 sulfate groups. RU ratios > 140, similar to those measured when PF4 was pre‐incubated with unfractionated heparin or enoxaparin, were obtained with purified dodeca‐ and tetradecasaccharides. RU values strongly correlated with the number of sulfate groups in the decasaccharides tested (r = 0.93, P=0.02).Conclusions:LMWHs with fragments > 10 saccharides and a large number of sulfate groups are more likely to be associated with a higher risk of HIT. These structure‐activity relationships were independent of the ability of the OS to bind antithrombin.

Analysis of the Tcell receptor TCR repertoire by flow cytometry proved to be relevant for investigating Tcell diversity and detecting reactive cells in blood samples. We used this approach to characterize nonmalignant Tlymphocytes in lymph nodes and give insights into their origin. The TCR repertoire of CD4 and CD8 Tcells from 81 lymph nodes was analyzed with a fourcolor flow cytometer using a wide panel of 25 antiVβ monoclonal antibodies. Flow cytometry proved to be a useful and informative technique. We demonstrated a diversified TCRVβ repertoire, and only low level expansions, in 53 of the samples. They involved nearly all Vβ families, were more frequent in the CD8 subset of older patients, but were not related to pathology. No evidence could be demonstrated in favor of stimulation by common antigens. Interestingly, the TCRVβ repertoire proved to be very similar in lymph nodes and blood samples. Our results argue that in the cases studied, lymph node enlargement is mainly due to an increased homing of circulating Tcells. They also provide reference values for expression of 25 TCRVβ in lymph nodes, which could serve as a basis for further applications in diagnosis of Tcell lymphoproliferative disorders. © 2009 International Society for Advancement of Cytometry

The synthesis and characterization of diblock and triblock copolymers produced by a two-component iniferter system is reported. These materials, designed for possible water treatment applications, consist of a hydrophilic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) block and a very low surface energy poly(1,1‘-dihydroperfluorooctyl methacrylate) (PFOMA) or poly(1,1,2,2-tetrahydroperfluorooctyl acrylate) (PTAN) block. Angle-dependent X-ray spectroscopy results and water contact angle measurements indicate that the surfaces of PDMAEMA-b-PFOMA diblock copolymers consist primarily of PFOMA. Transmission electron microscopy reveals that the block copolymers are microphase-separated, exhibiting either cylindrical or layered morphologies that do not change appreciably upon exposure to water. Both water uptake and water flux increase with increasing PDMAEMA content.

Objective:We describe a new human bladder carcinoma cell line (DAG–1) established from a resected bladder cancer fragment and maintained in culture for more than 5 years and over 300 passages. Methods and Results:Immunological, biochemical and molecular analysis showed that the DAG–1 cells (62 chromosomes) express the cytokeratines 8, 13, 18 and 20 that confirm their epithelial origin as well as numerous cytokine and cytokine receptor mRNAs. They secrete tissue–type plasminogen activator (t–PA), urokinase–type plasminogen activator (u–PA), plasminogen activator inhibitors (PAI–1 and PAI–2), and express u–PA receptors (u–PAR/CD87) at their surface. DAG–1 cells are resistant to TNFα– and IFNγ–induced apoptosis, two cytokines secreted in the urine of Calmette–Guérin bacillus–treated patients and involved in the tumor regression. Conclusion:The DAG–1 cell line is a useful tool, both in vitro and in vivo, to study the progression of bladder tumors and their mechanisms of resistance to immunotherapy in relation with PAI–2 and antioxidant enzymes.

Abstract: The generalized gamma (GG) distribution has a density function that can take on many possible forms commonly encountered in hydrologic applications. This fact has led many authors to study the properties of the distribution and to propose various estimation techniques (method of moments, mixed moments, maximum likelihood etc.). We discuss some of the most important properties of this flexible distribution and present a flexible method of parameter estimation, called the ldquogeneralized method of momentsrdquo (GMM) which combines any three moments of the GG distribution. The main advantage of this general method is that it has many of the previously proposed methods of estimation as special cases. We also give a general formula for the variance of theT-year eventX T obtained by the GMM along with a general formula for the parameter estimates and also for the covariances and correlation coefficients between any pair of such estimates. By applying the GMM and carefully choosing the order of the moments that are used in the estimation one can significantly reduce the variance ofT-year events for the range of return periods that are of interest.

Desmoplastic small round cell tumor is an aggressive neoplasm first described in 1991. Recently, a reciprocal translocation t( 11 ;22)(p 13 ;q 12) has been characterized by conventional cytogenetic studies and molecular analysis. This translocation involves the Ewing’s sarco- ma gene on chromosome 22 and the Wilms’ tumor gene WT1 on chromosome 11. The chimeric transcript corre- sponding to the fusion gene could be detected by the re- verse transcriptase-polymerase chain reaction (RT- PCR). Using an anti-WTl antibody, the WT1 part of the putative chimeric protein could be recognized by im- munohistochemistry. We describe two well-character- ized cases of intraabdominal desmoplastic small round cell tumor in two male patients aged 14 and 28 with both RT-PCR analysis and immunostaining for WT1. In this report, we insist on the necessity to increase the RT- PCR analysis in DSRCT in order to obtain a precise dif- ferential diagnosis. In addition, WT1 immunostaining may serve as a useful diagnostic marker for DSRCT.

A single-input/single-output (SISO) GPC algorithm and an ARX model identification routine were programmed on a graphical computing environment in the form of a portable “module.” Although attractive from an end-user (operator) standpoint, the selected platforms presented some programming challenges. The whole GPC module (controller and identification) was implemented on an industrial control system and applied to many sulfide flotation circuits in the Brunswick Mining concentrator (New Brunswick, Canada). The performance of the GPC controller is good on all the flotation circuits on which it is applied. Significant reductions of grade variance are reported and the controller exhibits good load and servo response.

MCL is a well-described clinicobiological entity that presents the worst prognosis of the small-cell lymphomas. No treatment is known as the reference treatment. On the basis, first, of cinicobiological similarities between MCLs and multiple myelomas and, second, of our experience of chiorambucil in high intermittent dose in MCLs, we have treated MCL with the VAD regimen both with and without chiorambucil.