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

Do different survey methods affect physicians’ stated work preferences? Findings from a discrete choice experiment in Eastern China

ObjectivesThis study aimed to examine the impact of online and offline survey methods on the participation of physicians in discrete choice experiment (DCE) surveys in Eastern China and explore their attitudes towards primary healthcare work.MethodsThe study involved active doctors practicing at secondary or county-level general hospitals in Eastern China, who completed a DCE questionnaire either online or offline. A mixed logit model was used to analyze the data, considering the relative importance of various job attributes.ResultsThis study found that online surveys save costs and offline surveys help increase the response rate for questionnaires. The validity rate for the completed questionnaires was high (>90%) across both research methods. A mixed logit model simulation analysis revealed that compensation packages were the dominant influence on doctors’ choices. The online survey showed that doctors were more likely to choose to work in village health centers if their salary was flat (β = 1.330), while the offline survey showed that doctors were also more likely to choose village health centers when their salary was increased by 10% (β = 1.095). Work organization and public recognition also had a significant effect on doctors’ primary job choices (p < 0.05).ConclusionThe study concluded that remuneration, work organization, and public recognition are key factors affecting physicians’ willingness to work in primary healthcare settings. For respondents with higher education and cognitive abilities, online surveys are recommended for DCE research

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

Effects of Salix psammophila on Groundwater Recharge in a Semiarid Area of North China

Study region: The semiarid Mu Us Sandy Land (MUSL) was selected for this study. It is in the farming-pastoral ecotone of north China and functions as an eco-environmental barrier. Study focus: Afforestation can mitigate desertification and soil erosion by improving hydrologic condition, which is particularly true for semiarid and arid regions. However, little is known about the quantitative response of hydrologic improvement to afforestation level that can be measured by leaf area index (LAI). The objective was to setup and use a physically-based model to quantitatively assess the dynamics of water fluxes from Salix psammophila afforestation in the MUSL. New hydrological insights for the region: Across the assessment period of 28 April to 3 October 2016, the total transpiration was determined to be about 294.4 mm. As LAI increased, while the transpiration tended to increase and the evaporation to decrease, the evapotranspiration tended to increase with increase of LAI until LAI =2.0 and then plateaued for LAI \u3e2.0. On the other hand, the recharge rate tended to decrease with increase of LAI until LAI =2.0 and then plateaued for LAI \u3e2.0. Overall, the impacts of Salix psammophila afforestation on soil-water replenishment and groundwater recharge would plateau for LAI \u3e2.0, mandating a good balance between solving large-scope eco-environmental problems by Salix psammophila afforestation and sustaining water resources in the long run

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

Efficient removal of Pb(II) and Cd(II) from aqueous solutions by mango seed biosorbent

Abundant fruit waste materials can be utilized as sustainable biosorbents for heavy metal removal from aqueous solutions. In this study, mango seed (MS) comprising seed kernel and shell showed the maximum adsorption capacities of 263.4 mg-Pb/g at pH 5.0 and 93.7 mg-Cd/g at pH 7.5. The best fitting of the adsorption isotherms to the Redlich-Peterson model indicated multilayer adsorption of Pb(II) and Cd(II) on the heterogeneous surface of MS. The adsorption was rapid with 93% of Pb(II) and 78% of Cd(II) adsorption accomplished within 10 min. More than 99% of the sequestered Pb(II) and 88% of the sequestered Cd(II) were recovered by desorption using 0.2 M HNO3, and the regenerated MS maintained 96–97% of the adsorption capacities. A combination of physicochemical and spectroscopic approaches showed that carboxyl, hydroxyl, amine, and ether groups were the binding sites; electrostatic attraction, microprecipitation, complexation, and ion exchange (with Ca2+ and Mg2+) jointly contributed to the adsorption. The seed kernel which has a more amorphous structure and a higher ion exchange capability favored higher Pb(II) and Cd(II) adsorption compared with the seed shell which contains a higher content of crystalline cellulose. These findings imply the application potential of MS for heavy metal removal and provide important information for the (bio)sorbent development.</p