Field‐Based Estimates of Thermal Tolerance Limits for Trout: Incorporating Exposure Time and Temperature Fluctuation

We used temperature and fish data from streams across Michigan and Wisconsin to estimate upper thermal tolerance limits for brook trout Salvelinus fontinalis and brown trout Salmo trutta. Tolerance limits were estimated for the maximum daily mean temperature (MEANT), maximum daily maximum temperature (MAXT), and maximum daily temperature range (RNGT) at exposure lengths of 1, 3, 7, 14, 21, 28, 35, 42, 49, 56, and 63 d. We found no difference in the upper thermal tolerance limit for brook and brown trout. For time periods of 1–14 d, the upper temperatures tolerated by trout decreased rapidly from 25.3°C to 22.5°C for MEANT and from 27.6°C to 24.6°C for MAXT. For time periods from 21 to 63 d, the upper temperatures tolerated by trout declined more gradually from 22.1°C to 21.0°C for MEANT and from 24.2°C to 22.9°C for MAXT. The 7‐d upper tolerance limit was 23.3°C for MEANT and 25.4°C for MAXT. The maximum RNGT tolerated by trout varied as a function of mean temperature and length of exposure. Our findings suggest that chronic temperature effects as well as temperature fluctuation play an important role in limiting salmonid distributions and therefore should be considered when developing management objectives and water quality standards.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141436/1/tafs0365.pd

A River Valley Segment Classification of Michigan Streams Based on Fish and Physical Attributes

Water resource managers are frequently interested in river and stream classification systems to generalize stream conditions and establish management policies over large spatial scales. We used fish assemblage data from 745 river valley segments to develop a two‐level, river valley segment‐scale classification system of rivers and streams throughout Michigan. Regression tree analyses distinguished 10 segment types based on mean July temperature and network catchment area and 26 segment types when channel gradient was also considered. Nonmetric multidimensional scaling analyses suggested that fish assemblages differed among segment types but were only slightly influenced by channel gradient. Species that were indicative of specific segment types generally had habitat requirements that matched segment attributes. A test of classification strength using fish assemblage data from an additional 77 river valley segments indicated that the classification system performed significantly better than random groupings of river valley segments. Our classification system for river valley segments overcomes several weaknesses of the classifications previously used in Michigan, and our approach may prove beneficial for developing classifications elsewhere.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141625/1/tafs1621.pd

A Comparison of Statistical Approaches for Predicting Stream Temperatures Across Heterogeneous Landscapes 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73725/1/j.1752-1688.2009.00341.x.pd

Microwave-assisted Acid-catalyzed Hydrolysis of Hemicelluloses in Rice Husk into Xylose

The development of an environmentally benign process for the hydrolysis of hemicelluloses into xylose could be one of the key technologies for making full use of biomass in the future. This paper studies dilute acid hydrolysis of hemicelluloses in rice husk (RH) into xylose using microwave radiation. Fourier transform infrared-attenuated total reflection spectroscopy was employed to quantitatively analyze xylose. The influences of hydrolysis parameters such as temperature, time, acid concentration, and ratio of RH to sulfuric acid on the yield of xylose in acid hydrolysis of RH were also investigated. The optimum hydrolysis conditions of hemicelluloses in RH to xylose are as follows: 4 wt% of H2SO4 concentration, 150 °C hydrolysis temperature, 25 min reaction time, and 1:7 ratio of RH (g) to H2SO4 (mL). Under optimum hydrolysis conditions, a yield of 32.96% xylose is obtained

Functional miR-142a-3p induces apoptosis and macrophage polarization by targeting tnfaip2 and glut3 in grass carp (Ctenopharyngodon idella)

In the process of microbial invasion, the inflammation reaction is induced to eliminate the pathogen. However, un-controlled or un-resolved inflammation can lead to tissue damage and death of the host. MicroRNAs (miRNAs) are the signaling regulators that prevent the uncontrolled progress of an inflammatory response. Our previous work strongly indicated that miR-142a-3p is related to the immune regulation in grass carp. In the present study, we found that the expression of miR-142a-3p was down-regulated after infection by Aeromonas hydrophila. tnfaip2 and glut3 were confirmed as be the target genes of miR-142a-3p, which were confirmed by expression correlation analysis, gene overexpression, and dual luciferase reporter assay. The miR-142a-3p can reduce cell viability and stimulate cell apoptosis by targeting tnfaip2 and glut3. In addition, miR-142a-3p also regulates macrophage polarization induced by A. hydrophila. Our results suggest that miR-142a-3p has multiple functions in host antibacterial immune response. Our research provides further understanding of the molecular mechanisms between miRNAs and their target genes, and provides a new insights for the development of pro-resolution strategies for the treatment of complex inflammatory diseases in fish.31802285, CARROS-45-03info:eu-repo/semantics/publishedVersio

Reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes: preparation of functionalized vinylcyclopropanes and cycloheptadienes

The reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes toward olefin metathesis, cycloaddition, and mild oxidations (MnO2 or mCPBA) was examined. Cycloaddition reactions were observed to occur with modest diastereoselectivity (33−63% de). Decomplexation of the (3-pentenediyl) ligand may be accomplished by oxidation with either CAN or alkaline hydrogen peroxide to afford vinylcyclopropanecarboxylates or divinylcyclopropanecarboxylates. Reduction of the latter, followed by Cope rearrangement generates cycloheptadienylmethanols. These studies demonstrate that (2-alkenyl-3-pentene-1,5-diyl)iron complexes can serve as organometallic scaffolds for the preparation of a wide variety of structural motifs containing up to 5 contiguous stereocenters

Simultaneous Determination of Selegiline, Desmethylselegiline, R/S-methamphetamine, and R/S-amphetamine on Dried Urine Spots by LC/MS/MS: Application to a Pharmacokinetic Study in Urine

Objective: Chiral analysis is a crucial method to differentiate selegiline intake from drug abuse. A dried urine spot (DUS) analytical method based on spotting urine samples (10 μL) onto dried spot collection cards, and followed by air-drying and extraction, was developed and validated for the determination of selegiline, desmethylselegiline, R/S-methamphetamine, and R/S-amphetamine.Methods: Methanol (0.5 mL) was found to be the ideal extraction solvent for target extraction from DUSs under orbital-horizontal stirring on a lateral shaker at 1,450 rpm for 30 min. Determinations were performed by direct electrospray ionization tandem mass spectrometry (ESI-MS/MS) under positive electrospray ionization conditions using multiple reaction monitoring mode. The chromatographic system consisted of a ChirobioticTM V2 column (2.1 × 250 mm, 5 μm) and a mobile phase of methanol containing 0.1% (v/v) glacial acetic acid and 0.02% (v/v) ammonium hydroxide.Results and conclusions: The calibration curves were linear from 50 to 5,000 ng/mL, with r > 0.995 for all analytes, imprecisions ≤ 15% and accuracies between −11.4 and 11.7%. Extraction recoveries ranged from 48.6 to 105.4% with coefficients of variation (CV) ≤ 13.7%, and matrix effects ranged from 45.4 to 104.1% with CV ≤ 10.3%. The lower limit of quantification was 50 ng/mL for each analyte. The present method is simple, rapid (accomplished in 12 min), sensitive, and validated by a pharmacokinetic study in human urine collected after a single oral administration of SG