We studied parental provisioning and chick growth rates of Cassin's auklet Ptychoramphus aleuticus at Triangle Island, British Columbia, Canada, from 1996 to 1999. Auklet reproductive performance and ocean climate conditions during these years were highly variable, and reflected in the diet composition. Chick growth was maximal when the diet was predominated by copepods, in particular Neocalanus cristatus. Provisioning and growth were high in 1999, intermediate in 1997 and poor in 1998. Exceptional was 1996, when growth was low but provisioning rates were high. Provisioning and growth were depressed late in 1997 and throughout 1998 when larval rockfish Sebastes spp. (5200 cal g ) in the nestling diet. Zooplankton surveys indicated that N. cristatus was substantially more abundant in May 1999 than in May 1998, and during 1999 the auklets foraged in areas with the highest concentrations of copepods. Through impacts on prey availability, variation in ocean climate affects the reproductive performance of Cassin's auklet. Performance tends to be favorable in years when spring is late and cold, and poor when spring is early and warm. Equations for predicting food delivery rates from 24 h mass changes of chicks were highly year-specific, precluding their application in other years or at other sites where Cassin's auklets breed. Between-year differences were also found in relationships between adult provisioning and chick growth. These were strongly positively related in 1999, positively related in 1996 and 1997, but unrelated in 1998; differences attributed to the magnitude of temporal variation in the nestling diet. Finally, we detected annual differences in parental response to chick needs. In 1999, parents delivered more food to chicks in poor condition and less to those in better condition, responses not observed in 1998. Different responses between years may have reflected variation in the availability of prey.
Comparative global proteome analyses were performed on Leptospira interrogans serovar Copenhageni grown under conventional in vitro conditions and those mimicking in vivo conditions (iron limitation and serum presence). Proteomic analyses were conducted using iTRAQ and LC-ESI-tandem mass spectrometry complemented with two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. A total of 563 proteins were identified in this study. Altered expression of 65 proteins, including upregulation of the L. interrogans virulence factor Loa22 and 5 novel proteins with homology to virulence factors found in other pathogens, was observed between the comparative conditions. Immunoblot analyses confirmed upregulation of 5 of the known or putative virulence factors in L. interrogans exposed to the in vivo-like environmental conditions. Further, ELISA analyses using serum from patients with leptospirosis and immunofluorescence studies performed on liver sections derived from L. interrogans-infected hamsters verified expression of all but one of the identified proteins during infection. These studies, which represent the first documented comparative global proteome analysis of Leptospira, demonstrated proteome alterations under conditions that mimic in vivo infection and allowed for the identification of novel putative L. interrogans virulence factors.
Tag loss in mark-recapture experiments is a violation of one of the Jolly-Seber model assumptions. It causes bias in parameter estimates and has only been dealt with in an ad hoc manner. We develop methodology to estimate tag retention and abundance in double-tagging mark-recapture experiments. We apply this methodology to walleyes (Stizostedion vitreum) in Mille Lacs, Minnesota.
Summary. Radio-tags are often used in capture-recapture studies because of their high detectability. A key assumption is that radio-tags do not cease functioning during the study. Radio-tag failure before the end of a study can lead to underestimates of survival rates. We develop a model to incorporate secondary radio-tag failure data. This model was applied to chinook smolts (Oncorhynchus tshawytscha) on the Columbia River, WA.Estimates of fish survival from this model were much larger than those from the standard Cormack-Jolly-Seber analysis.
Summary. Batch marking provides an important and efficient way to estimate the survival probabilities and population sizes of wild animals. It is particularly useful when dealing with animals that are difficult to mark individually. For the first time, we provide the likelihood for extended batch-marking experiments. It is often the case that samples contain individuals that remain unmarked, due to time and other constraints, and this information has not previously been analyzed. We provide ways of modeling such information, including an open N-mixture approach. We demonstrate that models for both marked and unmarked individuals are hidden Markov models; this provides a unified approach, and is the key to developing methods for fast likelihood computation and maximization. Likelihoods for marked and unmarked individuals can easily be combined using integrated population modeling. This allows the simultaneous estimation of population size and immigration, in addition to survival, as well as efficient estimation of standard errors and methods of model selection and evaluation, using standard likelihood techniques. Alternative methods for estimating population size are presented and compared. An illustration is provided by a weather-loach data set, previously analyzed by means of a complex procedure of constructing a pseudo likelihood, the formation of estimating equations, the use of sandwich estimates of variance, and piecemeal estimation of population size. Simulation provides general validation of the hidden Markov model methods developed and demonstrates their excellent performance and efficiency. This is especially notable due to the large numbers of hidden states that may be typically required
Syphilis is a sexually transmitted disease caused by Treponema pallidum subsp. pallidum; it can be effectively treated with penicillin yet remains prevalent worldwide, due in part to the shortcomings of current diagnostic tests. Here we report the production of soluble recombinant versions of three novel diagnostic candidate proteins, Tp0326, Tp0453, and a Tp0453-Tp0326 chimera. The sensitivities of these recombinant proteins were assessed by screening characterized serum samples from primary, secondary, and latent stages of infection (n ؍ 169). The specificities were assessed by screening false positives identified with the standard diagnostic testing algorithm (n ؍ 21), samples from patients with potentially cross-reactive infections (Leptospira spp., Borrelia burgdorferi, Helicobacter pylori, Epstein-Barr virus, hepatitis B virus, hepatitis C virus, or cytomegalovirus) (n ؍ 38), and samples from uninfected individuals (n ؍ 11). The sensitivities of Tp0326, Tp0453, and the Tp0453-Tp0326 chimera were found to be 86%, 98%, and 98%, respectively, and the specificities were 99%, 100%, and 99%. In a direct comparison, the Captia syphilis (T. pallidum)-G enzyme immunoassay (Trinity Biotech) was used to screen the same serum samples and was found to have a sensitivity of 98% and a specificity of 90%. In particular, Tp0453 and the chimera exhibited superior accuracy in classifying analytical false-positive samples (100%, compared to 43% for the Captia assay). These findings identify Tp0453 and the Tp0453-Tp0326 chimera as novel syphilis-specific diagnostic candidates that surpass the performance of a currently available diagnostic enzyme immunoassay test for syphilis and that allow accurate detection of all stages of infection.
Monitoring the dynamics of the productivity of ocean water and how it affects fisheries is essential for management. It requires data on proper spatial and temporal scales, which can be provided by operational ocean colour satellites. However, accurate productivity data from ocean colour imagery is only possible with proper validation of, for instance, the atmospheric correction applied to the images. In situ water reflectance data are of great value due to the requirements for validation and reflectance is traditionally measured with the Surface Acquisition System (SAS) solar tracker system. Recently, an application for mobile devices, "HydroColor", was developed to acquire water reflectance data. We examined the accuracy of the water reflectance measures acquired by HydroColor with the help of both trained and untrained citizens, under different environmental conditions. We used water reflectance data acquired by SAS solar tracker and by HydroColor onboard the BC ferry Queen of Oak Bay from July to September 2016. Monte Carlo permutation F tests were used to assess whether the differences between measurements collected by SAS solar tracker and HydroColor with citizens were significant. Results showed that citizen HydroColor measurements were accurate in red, green, and blue bands, as well as red/green and red/blue ratios under different environmental conditions. In addition, we found that a trained citizen obtained higher quality HydroColor data especially under clear skies at noon.
In capture–recapture studies, recycled individuals occur when individuals lose all of their tags and are recaptured as though they were new individuals. Typically, the effect of these recycled individuals is assumed negligible. Through a simulation‐based study of double‐tagging experiments, we examined the effect of recycled individuals on parameter estimates in the Jolly–Seber model with tag loss (Cowen & Schwarz, 2006). We validated the simulation framework using long‐term census data of elephant seals. Including recycled individuals did not affect estimates of capture, survival, and tag‐retention probabilities. However, with low tag‐retention rates, high capture rates, and high survival rates, recycled individuals produced overestimates of population size. For the elephant seal case study, we found population size estimates to be between 8% and 53% larger when recycled individuals were ignored. Ignoring the effects of recycled individuals can cause large biases in population size estimates. These results are particularly noticeable in longer studies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.