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Objective: Both electronic tags (e.g., acoustic and radio transmitters) and conventional external tags are used to evaluate movement and population dynamics of fish. External tags are also sometimes used to facilitate the recovery of internal electronic tags or other instrumentation because healing can make it difficult to identify fish with internal tags based on appearance alone. With both tag types, tag shedding and failure of electronic tags can affect accuracy and precision of study results. Methods: We used a decade (2011-2021) of recapture data for Walleye Sander vitreus tagged in the Laurentian Great Lakes, where fish were double-or triple-tagged with external tags (T-bar, loop, or internal anchor tags) and internal acoustic transmitters, to quantify external tag and internal transmitter shedding and transmitter failure rates. Result: In total, 1125 (33%) Walleye were recovered that had retained at least one external tag or internal transmitter. No confirmed cases of transmitter shedding were observed; 15 of 899 transmitters (2%) that were checked for functionality failed prior to the expected battery expiration. The retention of external T-bar tags 1 year after release differed depending on whether the tag was placed anterior or posterior to the secondary dorsal fin (anterior, fish length = 420 mm: 73% retention; anterior, fish length = 700 mm: 73%, posterior: 63%) but was <26% after 4 years for both tag positions and fish sizes. Internal anchor tags had an 88% 1-year retention probability and 81% 4-year retention probability. Loop tags had the highest 1-year retention (89%) but after 4 years retention (28-34% depending on agency) was comparable to that of T-bar tags. Conclusion: Better understanding of tag retention characteristics through long-term tagging studies such as this can inform study design, be considered in model design, and ultimately improve inferences from mark-recapture studies. [ABSTRACT FROM AUTHOR]

We have developed a new thermodynamic theory of the quasiliquid layer, which has been shown to be effective in modeling the phenomenon in a number of molecular systems. Here we extend our analysis to H2O ice, which has obvious implications for environmental and atmospheric chemistry. In the model, the liquid layer exists in contact with an ice defined as a two-dimensional lattice of sites. The system free energy is defined by the bulk free energies of ice Ih and liquid water and is minimized in the grand canonical ensemble. An additional configurational entropy term arises from the occupation of the lattice sites. Furthermore, the theory predicts that the layer thickness as a function of temperature depends only on the liquid activity. Two additional models are derived, where slightly different approximations are used to define the free energy. With these two models, we illustrate the connection between the quasiliquid phenomenon and multilayer adsorption and the possibility of a two-dimensional phase transition connecting a dilute low coverage phase of adsorbed H2O and the quasiliquid phase. The model predictions are in agreement with a subset of the total suite of experimental measurements of the liquid thickness on H2O ice as a function of temperature. The theory indicates that the quasiliquid layer is actually equivalent to normal liquid water, and we discuss the impact of such an identification. In particular, observations of the liquid layer to temperatures as low as 200 K indicate the possibility that the quasiliquid is, in fact, an example of deeply supercooled normal water. Finally, we briefly discuss the obvious extension of the pure liquid theory to a thermodynamic theory of interfacial solutions on ice in the environment. [ABSTRACT FROM AUTHOR]

The adsorption of HCl on the surface of H2O ice has been measured at temperatures and pressures relevant to the upper troposphere and lower stratosphere. The measured HCl surface coverage is found to be at least 100 times lower than currently assumed in models of chlorine catalyzed ozone destruction in cold regions of the upper atmosphere. Measurements were conducted in a closed system by simultaneous application of surface spectroscopy and gas phase mass spectrometry to fully characterize vapor/solid equilibrium. Surface adsorption is clearly distinguished from bulk liquid or solid phases. From 180 to 200 K, submonolayer adsorption of HCl is well described by a Bragg-Williams modified Langmuir model which includes the dissociation of HCl into H+ and Cl- ions. Furthermore, adsorption is consistent with two distinct states on the ice substrate, one in which the ions only weakly adsorb on separate sites, and another where the ions adsorb as an H+-Cl- pair on a single site with adsorption energy comparable to the bulk trihydrate. The number of substrate H2O molecules per adsorption site is also consistent with the stoichiometry of bulk hydrates under these conditions. The ionic states exist in equilibrium, and the total adsorption energy is a function of the relative population of both states. These observations and model provide a quantitative connection between the thermodynamics of the bulk and interfacial phases of HCl/H2O, and represent a consistent physicochemical model of the equilibrium system. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Optical atomic clocks require local oscillators with exceptional optical coherence owing to the challenge of performing spectroscopy on their ultranarrow-linewidth clock transitions. Advances in laser stabilization have thus enabled rapid progress in clock precision. A new class of ultrastable lasers based on cryogenic silicon reference cavities has recently demonstrated the longest optical coherence times to date. Here we utilize such a local oscillator with two strontium (Sr) optical lattice clocks to achieve an advance in clock stability. Through an anti-synchronous comparison, the fractional instability of both clocks is assessed to be 4.8 × 1 0 - 17 ∕ τ for an averaging time τ (in seconds). Synchronous interrogation enables each clock to average at a rate of 3.5 × 1 0 - 17 ∕ τ , dominated by quantum projection noise, and reach an instability of 6.6 × 10−19 over an hour-long measurement. The ability to resolve sub-10−18-level frequency shifts in such short timescales will affect a wide range of applications for clocks in quantum sensing and fundamental physics. By using an ultrastable oscillator based on a cryogenic Si cavity, the fractional instability of two Sr optical lattice clocks at 1 s reaches 4.8 × 10−17 and 3.5 × 10−17 through anti-synchronous and synchronous comparisons, respectively. [ABSTRACT FROM AUTHOR]

Overtone vibration–laser double resonance studies of DF(v=1–3) energy transfer yield self-relaxation rate constants for v=1, 2 and 3 of k1=(0.37±0.06)×10-12 cm3 mol-1 s-1, k2=(22.0±2.0)×10-12 cm3 mol-1 s-1, and k3=(17.0±1.8)×10-12 cm3 mol-1 s-1, respectively. The approach also directly measures the relative importance of vibration-to-vibration (V–V) and vibration-to-translation-and-rotation (V–T,R) energy transfer. The fraction of DF(v) molecules relaxing by V–V energy transfer is 1.1±0.1 and 0.72±0.10 for v=2 and v=3, respectively. Essentially all of the vibrational energy transfer in v=2 occurs via the V–V mechanism. The slower relaxation of DF(v=3) compared to DF(v=2), in contrast to simple scaling law predictions, reflects the decreasing influence of the V–V mechanism, even though it is still the primary relaxation pathway for DF(v=3). Comparison with HF self-relaxation qualitatively indicates that V–R energy transfer is important in V–T,R relaxation of DF(v=1). [ABSTRACT FROM AUTHOR]

Overtone vibration-laser double resonance measurements determine the vibrational relaxation rates of DF(v=1) and HF(v=1) by the DF dimer. Both monomers are efficiently relaxed by the dimer at a rate that is 20% of the gas kinetic rate. The similarity of the rate constants for the two systems, which have very different energy defects, indicates that the relaxation occurs by collision complex formation and energy redistribution, rather than direct vibration-to-vibration energy transfer from the monomer to the dimer. [ABSTRACT FROM AUTHOR]

Overtone vibration-laser double resonance directly measures the relative importance of vibration-to-vibration and vibration-to-translation-and-rotation energy transfer for HF(v=3 and v=4) at room temperature. The fraction of HF(v) molecules relaxing by V–V energy transfer is 0.44±0.05 and 0.16±0.05 for v=3 and v=4, respectively, compared to 0.59±0.10 for v=2. These measurements show that V–T,R energy transfer is the dominant relaxation mechanism for HF(v≥3) and the observed decreased amount of V–V energy transfer for higher initially excited vibrational levels is in good agreement with a chemiluminescence measurement and several theoretical calculations. The data demonstrate that the magnitude of the energy defects for the component pathways primarily determines the energy transfer mechanism for HF(v=2–4). [ABSTRACT FROM AUTHOR]

The temperature dependencies of the total self-relaxation rate constants for the vibrational deactivation of HF(v=2) and HF(v=1) and the state-to-state vibration-to-vibration (V–V) and vibration-to-translation-and-rotation (V-T,R) energy transfer components of the HF(v=2) self-relaxation process are measured using the overtone vibration excitation-laser double resonance technique. The total self-relaxation rate constants vary inversely with temperature. The much weaker temperature dependence of HF(v=2) self-relaxation compared to that of HF(v=1) arises from the significant role of the V–V energy transfer route. Competition between energetics and collision duration results in a weaker inverse variation with temperature for the slightly endothermic V–V route than for the exothermic V-T,R route for HF(v=2). The branching ratio for V–V energy transfer increases slightly with temperature and the data suggest that two quantum relaxation processes constitute no more than 10% of the total self-relaxation of HF(v=2). The available temperature dependence data on self-relaxation of HF(v=1–5) form a consistent picture in which the energetics of the V–V and V-T,R relaxation pathways control their relative contributions to the total energy transfer. [ABSTRACT FROM AUTHOR]

Overtone vibration–laser double resonance measurements determine the vibrational relaxation rate of HF(v=1) by HF dimers. Vibration-to-vibration energy transfer from the excited monomer to the dimer followed by vibrational predissociation of the dimer provides an efficient pathway for vibration-to-translation energy transfer that deexcites the monomer at 40% of the gas kinetic collision rate. Analysis of the pressure dependence of the observed decay constants using a simple kinetic model establishes a rough upper limit of 10 ns on the predissociation lifetime of the collisionally excited dimer. [ABSTRACT FROM AUTHOR]

Objective: We report a method using functional-molecular databases and network modelling to identify hypothetical mRNA--miRNA interaction networks regulating intestinal epithelial barrier function. The model forms a data-analysis component of our cell culture experiments, which produce RNA expression data from Nanostring Technologies nCounter® system. The epithelial tight-junction (TJ) and actin cytoskeleton interact as molecular components of the intestinal epithelial barrier. Upstream regulation of TJ-cytoskeleton interaction is effected by the Rac/Rock/Rho signaling pathway and other associated pathways which may be activated or suppressed by extracellular signaling from growth factors, hormones, and immune receptors. Pathway activations affect epithelial homeostasis, contributing to degradation of the epithelial barrier associated with osmotic dysregulation, inflammation, and tumor development. The complexity underlying miRNA--mRNA interaction networks represents a roadblock for prediction and validation of competing-endogenous RNA network function. Results: We developed a network model to identify hypothetical co-regulatory motifs in a miRNA--mRNA interaction network related to epithelial function. A mRNA--miRNA interaction list was generated using KEGG and miRWalk2.0 databases. R-code was developed to quantify and visualize inherent network structures. We identified a sub-network with a high number of shared, targeting miRNAs, of genes associated with cellular proliferation and cancer, including c-MYC and Cyclin D. [ABSTRACT FROM AUTHOR]

A rudimentary understanding of age, growth, and life-span is lacking for many non-game fishes. Growth characteristics of the central mudminnow ( Umbra limi) have not yet been accurately described using reliable hard part analysis. The utility of scales and otoliths as ageing structures and quantified growth was examined in one lake and one stream population of central mudminnow. Scales were found to be of no utility in determining age due to inconsistent formation of yearly annuli and a high incidence of regenerated scales, while otoliths were easily extracted and considered to be an accurate ageing structure. Ages determined from scales were low compared to those from otoliths, and the difference in age interpreted from the two structures increased with fish age. A power function was fitted to describe the length-weight relationship for this species ( a = 0.0069, b = 3.175). Von Bertalanffy growth parameters were estimated and compared for each population (Lake: L∞ = 114.20 mm, K = 0.30, t0 = −0.93; Stream: L∞ = 77.59 mm, K = 0.63, t0 = −0.76). The lake population showed greater size at age compared to the stream population, especially at older ages, and achieved a larger maximum size. Growth rate was also greater in the lake population (Lake: 1.74; Stream: 1.09 g year−1). Females were larger at age than males in both populations, however all individuals greater than age 3 were males. This work represents the first successful account of central mudminnow growth using hard part analysis. [ABSTRACT FROM AUTHOR]

The earliest evidence for animal life comes from the fossil record of 24-isopropylcholestane, a sterane found in Cryogenian deposits, and whose precursors are found in modern demosponges, but not choanoflagellates, calcareans, hexactinellids, or eumetazoans. However, many modern demosponges are also characterized by the presence of siliceous spicules, and there are no convincing demosponge spicules in strata older than the Cambrian. This temporal disparity highlights a problem with our understanding of the Precambrian fossil record – either these supposed demosponge-specific biomarkers were derived from the sterols of some other organism and are simply retained in modern demosponges, or spicules do not primitively characterize crown-group demosponges. Resolving this issue requires resolving the phylogenetic placement of another group of sponges, the hexactinellids, which not only make a spicule thought to be homologous to the spicules of demosponges, but also make their first appearance near the Precambrian/Cambrian boundary. Using two independent analytical approaches and data sets – traditional molecular phylogenetic analyses and the presence or absence of specific microRNA genes – we show that demosponges are monophyletic, and that hexactinellids are their sister group (together forming the Silicea). Thus, spicules must have evolved before the last common ancestor of all living siliceans, suggesting the presence of a significant gap in the silicean spicule fossil record. Molecular divergence estimates date the origin of this last common ancestor well within the Cryogenian, consistent with the biomarker record, and strongly suggests that siliceous spicules were present during the Precambrian but were not preserved. [ABSTRACT FROM AUTHOR]

NBI-6024 is an altered peptide ligand (APL) corresponding to the 9–23 amino acid region of the insulin B chain (B(9−23)), an epitope recognized by inflammatory interferon-γ-producing T helper (Th)1 lymphocytes in type 1 diabetic patients. Immunomodulatory effects of NBI-6024 administration in recent-onset diabetic patients in a phase I clinical trial (NBI-6024-0003) were measured in peripheral blood mononuclear cells using the enzyme-linked immunosorbent spot assay. Analysis of the mean magnitude of cytokine responses to B(9−23) and NBI-6024 for each cohort showed significant increases in interleukin-5 responses (a Th2 regulatory phenotype) in cohorts that received APL relative to those receiving placebo. A responder analysis showed that Th1 responses to B(9−23) and NBI-6024 were observed almost exclusively in the placebo-treated diabetic population but not in nondiabetic control subjects and that APL administration (five biweekly subcutaneous injections) significantly and dose-dependently reduced the percentage of patients with these Th1 responses. The results of this phase I clinical study strongly suggest that NBI-6024 treatment shifted the Th1 pathogenic responses in recent-onset type 1 diabetic patients to a protective Th2 regulatory phenotype. The significance of these findings on the clinical outcome of disease is currently under investigation in a phase II multidose study. [ABSTRACT FROM AUTHOR]