Search

Much effort has been devoted to predicting fish migration routes to assist target species migration, and yet, fish migration science and practice remain imperfect. This study aimed to predict the migration paths of Gymnocypris przewalskii at the river confluence in the Qinghai Lake basin. The authors proposed an approach for fish migration route prediction, which involves a hydrodynamic module, a habitat model and a fish migration module. The TELEMAC‐MASCARET system was used to simulate hydrodynamic conditions and statistical analyses were carried out. During the flood season, G. przewalskii migrates downstream, whereas during the migratory season, they migrate upstream. The results indicate that flow velocity was the most significant hydrodynamic parameter affecting fish migration behaviour. The optimal flow velocity range for the target fish species was between 0.7 and 1.7 m/s. The impact of water depth was only observed in low discharge situations. Besides, the temperature plays a vital role in determining fish migration and abundance. However, the results reveal that in the morning hours, the temperature exhibits a range of 10°C to 16°C, and in the noon, the average temperature ranges from 16°C to 19°C, with a maximum temperature reaching 23°C. These temperature variations enable fish to migrate towards the tributary offering a more favourable water temperature during route selection at a river confluence. The study concludes that future research should consider incorporating the swimming capacity of the focal fish species to provide insights into fish migration patterns. [ABSTRACT FROM AUTHOR]

Channel constructions significantly impact river hydrodynamics, subsequently influencing river ecosystems. To mitigate the negative influence of channel construction and protect fish habitat, it is essential to evaluate fish habitat suitability through the integration of hydrodynamic and habitat models. This study models channel constructions on both the left and right riverbanks to evaluate habitat suitability for Four Major Chinese Carps and the Chinese sturgeon. Initially, flow velocity, water depth and grain size are simulated, followed by an assessment of habitat conditions using the Habitat Suitability Index (HSI) for three distinct construction strategies. Results reveal that constructing channels on the left bank mitigates adverse effects on fish habitat, while constructions on the right bank and both riverbanks lead to habitat degradation. Long‐term effects on riverbed elevation and fish habitat suitability post‐construction were also investigated. Notably, the Four Major Chinese Carps consistently demonstrate greater suitability for the studied river, regardless of flow rate or construction strategies, in comparison to the Chinese sturgeon. These findings underscore diverse responses to channel construction, providing valuable insights for identifying critical habitat areas for endemic fish conservation. This research presents a robust framework for assessing fish ecology in river systems, offering support for conservation decision‐makers. [ABSTRACT FROM AUTHOR]

Flowering time and growth period are key agronomic traits which directly affect soybean (Glycine max (L.) Merr.) adaptation to diverse latitudes and farming systems. The FLOWERING LOCUS T (FT) homologs GmFT2a and GmFT5a integrate multiple flowering regulation pathways and significantly advance flowering and maturity in soybean. Pinpointing the genes responsible for regulating GmFT2a and GmFT5a will improve our understanding of the molecular mechanisms governing growth period in soybean. In this study, we identified the Nuclear Factor Y‐C (NFY‐C) protein GmNF‐YC4 as a novel flowering suppressor in soybean under long‐day (LD) conditions. GmNF‐YC4 delays flowering and maturation by directly repressing the expression of GmFT2a and GmFT5a. In addition, we found that a strong selective sweep event occurred in the chromosomal region harboring the GmNF‐YC4 gene during soybean domestication. The GmNF‐YC4Hap3 allele was mainly found in wild soybean (Glycine soja Siebold & Zucc.) and has been eliminated from G. max landraces and improved cultivars, which predominantly contain the GmNF‐YC4Hap1 allele. Furthermore, the Gmnf‐yc4 mutants displayed notably accelerated flowering and maturation under LD conditions. These alleles may prove to be valuable genetic resources for enhancing soybean adaptability to higher latitudes. [ABSTRACT FROM AUTHOR]

Dam construction and operation can result in serious disturbances to the downstream flow regime and fluvial process, river morphology and the river's ecological condition worldwide. To understand the effects of discharge and sedimentation on fish habitats and ecosystems, an ecohydraulic approach was applied to one of the mega hydropower schemes in the downstream Lancang River (Tibet). The approach comprised a dam operation module with high flow and sediment transport and the application of a dynamic fish habitat model for assessing habitat fragmentation of two targeted fish species: Schizothorax prenanti (S. prenanti) and Schizothorax davidi (S. davidi). The hydrodynamics of the river system and the assessed fish habitat show a significant impact of dam construction and operation on the downstream riverine ecosystem, in which fish habitats were found rapidly deteriorated with the destruction of feeding and reproductive grounds. To improve fish habitat after dam construction, the sediment supplement was applied to the river and shown to be a useful restoration strategy, which recovers the habitat fragmentation of target fish. Our model not only is useful to predict dam operation impacts on the Lancang River's ecological status but also shows great potential in mitigating hydropower‐induced environmental impacts and developing river conservation guidelines worldwide. [ABSTRACT FROM AUTHOR]

Dam construction alters the hydrodynamic conditions, consequently impacting the swimming behavior of fish. To explore the effect of flow hydrodynamics on fish swimming behavior, five endemic fish species in the upper Yangtze River basin were selected. Through high‐speed video visualization and computer analysis, these species' swimming patterns under different flow velocities (0.1–1.2 m/s) were investigated. The kinematic and morphological characteristics of the fish were presented. The principal component analysis was used to analyse the main factors influencing the swimming ability of fish and to determine the correlation coefficients among fish behavior indicators. Fish exhibited three different swimming patterns under different flow velocities. Low velocity (0.1–0.3 m/s) corresponds to free motion, middle velocity (0.4–0.7 m/s) corresponds to cruising motion, and high velocity corresponds to stress motion (0.8–1.2 m/s). The fish kinematic index curves were obtained, and four of five fish species showed two extreme points, which means the optimal and adverse swimming strategies can be determined. With the increase in flow velocity, the tail‐beat frequency showed an increasing trend, whereas the tail‐beat angle and amplitude showed a decreasing trend. Morphological and kinematic parameters were the two main indexes that affect the swimming ability of fish, which accounts for 41.9% and 26.9%, respectively. [ABSTRACT FROM AUTHOR]

An ecohydraulic model system was developed to evaluate the effects of the Da‐Wei dam construction and possible fish restoration strategies. The ecohydraulic model system consists of a hydrodynamic model, a hydromorphology model, a habitat model, and the logistic and matrix population models. The effects of dam construction and fish stocking strategy on fish habitat and population status were studied in the Jiao‐Mu River, providing the modeled ecological status of Schizothorax prenanti and Schizothorax plagiostomus heckel populations within the river segment. The two fish species richness, fish age structures, and fish density distributions were predicted. Based on the fish number prediction, the optimal number of fish to stock was evaluated with the population models, and an optimal fish stocking proposition was worked out. The results indicated that the two fish species habitat quality and fish richness would decrease due to the hydropower dam construction, and the fish stocking strategy could make up the fish species ecological status. The findings could facilitate the quantity and quality assessment of a dam development plan and increase the success rate of fish restoration. [ABSTRACT FROM AUTHOR]

Riffle‐pool constructions are common practice in river management and fish conservation, but insufficient science exists to guide objective design of riffle‐pool. Understanding the spatial design of a riffle‐pool in river systems has significant value because it can provide important information to ameliorate aquatic species decline. In this study, six types of riffle‐pool structures were designed to assess hydrodynamic and riverbed morphology effects on stream habitat status. A two‐dimensional ecohydraulic model was used to assess the roles of different riffle‐pool designs in river habitat conditions. The natural flow condition and three types of flood flow conditions were applied to the six types of riffle‐pool structures to evaluate the habitat quality and the sustainability of the riffle‐pool design in mountain rivers. The long‐term impacts of the hydrodynamic and hydromorphology conditions on river physical habitat status were also analysed. The results indicate substantial differences in habitat quality among six riffle‐pool structures. It was found that narrow riffle‐pool construction yielded the best performance for the fish habitat, which had the best habitat quality among six riffle‐pool designs with the smallest pool area. In the same riffle‐pool structure, the habitat suitability in the riffle‐pool sequence will primarily increase more rapidly and then decrease gradually along with the discharge increase. Under the flood discharge scenarios, low flood discharge could improve riffle‐pool habitat quality, while high flood discharge could fragment the riffle‐pool habitat quality further. The long‐term hydrodynamic conditions have the same effects on all six cases. Overall, low discharge and smaller pool design would be beneficial to the river system, which could help maintain habitat diversity of mountain rivers. This analysis could provide valuable information for river management and decision‐making, which could assist in designing better mountain river habitats to promote conservation and rehabilitation of endangered biota. [ABSTRACT FROM AUTHOR]

Breast cancer is the highest incidence among female cancers in the world, but the approved clinical drugs have strong side effects, and some even have carcinogenic effects. Lonidamine has attracted much attention due to its stronger inhibitory effect and smaller side effects for breast cancer, but its low bioavailability limits its clinical application. To overcome this challenge, we hope to further enhance its effect of inhibiting cancer cell proliferation and increase its bioavailability by modifying the structure of lonidamine. After continuous efforts, we designed and synthesized two drug molecules 18a (YRL‐01) and 18b (YRL‐02) with higher inhibitory activity than lonidamine based on the structure‐based drug design strategy, with IC50 values of 45 μM and 53 μM, respectively. Subsequent molecular docking experiments showed that these two molecules should act by targeting the estrogen receptoralpha (ERα). We believe that the research results will provide meaningful guidance for the design and development of innovative drugs against breast cancer in the future. [ABSTRACT FROM AUTHOR]

Non‐obstructive azoospermia is one of the most common causes of male infertility, but there is still no specific treatment drug. Given that the Oct4 (Octamer‐binding transcription factor 4) has an important regulatory effect on spermatogenesis, activating it can effectively promote spermatogenesis, so it is of great value to develop Oct4‐targeted drug design and elucidating its mechanism of action. Here, we screened out the Oct4‐targeted drug molecule NBMA (N‐benzyl‐4‐methoxy‐2‐(1‐(4‐(trifluoromethyl)phenyl)vinyl)aniline) by computer‐assisted technology, and found that it has a significant promoting effect on spermatogenesis in the established mouse azoospermia model. Subsequently, through transcriptome sequencing and enrichment analysis, real‐time fluorescent quantitative PCR (qPCR) and western blot experiments revealed that NBMA promotes the differentiation of spermatogonial stem cells by activating the Oct4 pathway, thereby promoting spermatogenesis. This study proves that NBMA is a molecule with great potential to be developed as a therapeutic drug for azoospermia. It also shows that computer‐assisted, chemical and biological multidisciplinary methods play a very important role in innovative drug discovery. [ABSTRACT FROM AUTHOR]

Day length has an important influence on flowering and growth habit in many plant species. In crops such as soybean, photoperiod sensitivity determines the geographical range over which a given cultivar can grow and flower. The soybean genome contains ~10 genes homologous to FT, a central regulator of flowering from Arabidopsis thaliana. However, the precise roles of these soybean FTs are not clearly. Here we show that one such gene, GmFT2b, promotes flowering under long‐days (LDs). Overexpression of GmFT2b upregulates expression of flowering‐related genes which are important in regulating flowering time. We propose a 'weight' model for soybean flowering under short‐day (SD) and LD conditions. Furthermore, we examine GmFT2b sequences in 195 soybean cultivars, as well as flowering phenotypes, geographical distributions and maturity groups. We found that Hap3, a major GmFT2b haplotype, is associated with significantly earlier flowering at higher latitudes. We anticipate our assay to provide important resources for the genetic improvement of soybean, including new germplasm for soybean breeding, and also increase our understanding of functional diversity in the soybean FT gene family. In an effort to understand the molecular genetic basis of flowering time in soybean, we have isolated and characterized GmFT2b, a soybean FT gene homolog. We used overexpression and CRISPR/Cas9‐induced targeted gene mutations to show that GmFT2b regulates flowering in soybean, but only under long days. We also sequenced this gene from 195 soybean cultivars in different maturity groups (MGs). Our analysis showed that one GmFT2b haplotype, Hap3, is found only in early‐maturing cultivars in MGs 0–2, and correlates with their ability to flower in environments located at high latitudes in northeastern China. [ABSTRACT FROM AUTHOR]

Summary: Flowering time is a key agronomic trait that directly influences the successful adaptation of soybean (Glycine max) to diverse latitudes and farming systems. GmFT2a and GmFT5a have been extensively identified as flowering activators and integrators in soybean. Here, we identified two quantitative trait loci (QTLs) regions harbouring GmFT2a and GmFT5a, respectively, associated with different genetic effects on flowering under different photoperiods. We analysed the flowering time of transgenic plants overexpressing GmFT2a or GmFT5a, ft2a mutants, ft5a mutants and ft2aft5a double mutants under long‐day (LD) and short‐day (SD) conditions. We confirmed that GmFT2a and GmFT5a are not redundant, they collectively regulate flowering time, and the effect of GmFT2a is more prominent than that of GmFT5a under SD conditions whereas GmFT5a has more significant effects than GmFT2a under LD conditions. GmFT5a, not GmFT2a, was essential for soybean to adapt to high latitude regions. The ft2aft5a double mutants showed late flowering by about 31.3 days under SD conditions and produced significantly increased numbers of pods and seeds per plant compared to the wild type. We speculate that these mutants may have enormous yield potential for the tropics. In addition, we examined the sequences of these two loci in 202 soybean accessions and investigated the flowering phenotypes, geographical distributions and maturity groups within major haplotypes. These results will contribute to soybean breeding and regional adaptability. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: An eco‐hydraulic model is described, namely, “WW‐Eco‐tools.” The model is composed of hydro‐morpho‐dynamic, habitat, and population models. Fish habitat suitability models assess habitat quality, based on abiotic parameters, namely, flow velocity, depth, and substratum data. These are all derived from a hydro‐morpho‐dynamic model. The relationships between parameters and habitat features are represented as suitability index curves (SI curves) or fuzzy rules. To dynamically simulate fish species, two different population models are developed. The first is converted from a logistic population concept. Its model parameters are related to time‐dependent fish habitat conditions, namely, weighted usable areas and an overall suitability index. The second model is based on a matrix population concept, with numbers as the only state vector. Age‐specific fecundities and survival rates depend on the habitat qualities defined in the matrix population model. The eco‐hydraulic model provides very promising results, highlighting the fundamental role of temporal variability of hydro‐morphological parameters in structuring habitat and populations of fish species. Using this software to anticipate water management changes, simulated population trends can help decision‐makers optimize management measures. [ABSTRACT FROM AUTHOR]

The sterically bulky Schiff-base ligand 1 (L1H) was treated with CH3MgI in toluene to give the unexpected homoleptic magnesium complex 2 (L1MgL1) in good yield. However, the reaction of sterically more bulky ligand 3 (L2H) with CH3MgI in diethyl ether yielded the desired heteroleptic magnesium iodide 4 [L2MgI(OEt2)], which was further reduced with sodium to produce the Mg-Na heterodimetallic complex 5. The crystal structures of all new magnesium complexes were determined by single-crystal X-ray diffraction. All new magnesium complexes have been investigated as catalysts for the hydrosilylation of ketones with (EtO)3SiH. The study showed that catalytic activity of the Mg-Na dimetallic complex 5 is superior to those of monometallic magnesium complexes 2 and 4 and is applicable to a series of subatrates. [ABSTRACT FROM AUTHOR]