Evaluation of Yield Attributing Trait of Spring Wheat Genotypes Under Normal and Late Sowing Condition

Wheat (Triticum aestivum) is the third most important cereal crop in Nepal after rice and maize. The research is carried out during the winter season in agronomic field of the Institute of Agriculture and Animal Science (IAAS), Bhairahawa, Nepal. Sowing is carried out 28th November 2020 and 24th December 2020 on alpha lattice design with two replication of twenty wheat genotype under normal and late sowing respectively. In the late sowing condition, all genotype's performance is reduced as compared to normal sowing. Under late sown condition, high temperatures reduced the days to booting (15.64%), days to heading (14.97%), days to maturity (14.16%), chlorophyll content (15.99%), plant height (8.59%), spike length (7.03%), number of spikelet per spike (9.21%), number of grain per spike (10.6%), spike weight (15.32%), effective tiller/m2 (9.92%), thousand kernel weight (10.3%) and grain yield (22.5%). NL 1420 presented higher 4118 kg/ha and 3310.5 kg/ha yield respectively and BL 4407 presented early maturity 119.2 DAS and 100.6 DAS respectively in normal sowing and late sowing condition. In a combined environment, maximum grain yield is recorded in NL1420. The result suggested that the tolerant line against the late sowing condition can be used as genetic resource for crop improvement and promote for grain yield

Relationship between Wheat Yield and Yield Attributing Character at Late Sowing Condition

Correlation coefficient and path analysis were computed between yield and yield attributing trait among twenty genotypes of wheat. The research was conducted during winter season of 2020/2021 in the agronomic field of the Institute of Agriculture and Animal Science (IAAS), Bhairahawa, Nepal to identify the traits which influence the positive and negative relation to grain yield. Twenty genotypes of wheat were sown on 24th December 2020 on alpha lattice design with two replications. It has been found that under heat stress, DTB, DTH, DTM, CLC, PH, NGPS show a non-significant positive correlation with GY. Similarly ET shows a highly significant positive correlation to GY. However, SL, SW, TKW have a non-significant negative correlation with GY. In path analysis, DTM and ET have a positive direct effect on GY and DTH, SL, CLC and NGPS have an indirect effect on GY. Hence, the ET and DTM can be used to select wheat genotype for breeding purpose and studies to improve yield of genotypes under heat stress condition

Multiple isotope and hydro-chemical techniques investigating dynamics and sources of dic within a multiple aquifer system of a groundwater fed lake catchment (Lough Gur, Ireland)

Lake groundwater discharge, isotope, biogeochemical processe

Selection of Reference Genes for Expression Analysis in Chinese Medicinal Herb Huperzia serrata

Huperzine A (HupA) is a powerful and selective inhibitor of acetylcholinesterase. It has attracted widespread attention endangering the ultimate plant sources of Lycopodiaceae family. In this study, we used Huperzia serrata, extensively used in Traditional Chinese medicine (TCM), a slow growing vascular plant as the model plant of the Lycopodiaceae family to develop and validate the reference genes. We aim to use gene expression platform to understand the gene expression of different tissues and developmental stages of this medicinal herb. Eight candidate reference genes were selected based on RNA-seq data and evaluated with qRT-PCR. The expression of L/ODC and cytochrome P450s genes known for their involvement in lycopodium alkaloid biosynthesis, were also studied to validate the selected reference genes. The most stable genes were TBP, GAPDH, and their combination (TBP + GAPDH). We report for the first time the reference gene of H. serrata’s different tissues which would provide important insights into understanding their biological functions comparing other Lycopodiaceae plants and facilitate a good biopharming approach

Transport and Retention of High Concentrated Nano-Fe/Cu Particles Through Highly Flow-Rated Packed Sand Column

The design of an efficient field-scale remediation based on the use of nanoscale zero valent iron (NZVI) requires an accurate assessment of the mobility of such particles in saturated porous media, both during injection in the subsurface (short-term mobility) and later (long-term mobility). In this study, the mobility of highly concentrated dispersions of bimetallic Fe/Cu nanoparticles (d50= 70±5 nm) in sand-packed columns (0.5 m length and 0.025 m inner diameter) was studied. In particular, the influence of flow rate (V = 5×10-4, 1×10-3, 2×10-3 m/s) and injected particle concentrations (2, 5, 8, 12 g/l) was addressed. Breakthrough curves and water pressure drop along the column, averaged effective porosity and final distribution of retained particles along the column were measured. Experimental results evidenced a good mobility of the Fe/Cu particles, with significant breakthrough in all explored experimental conditions of flow rate and C0, without requiring the addition of any stabilizing agent. Clogging phenomenon of the column and also the pore pressure variation during injection period are strongly affected by injected concentration. Clogging due to deposition of particles following a ripening dynamics was observed in particular for C0= 8 and 12 g/l. The experimental data were 23 modeled using the E-MNM1D software. The study has implications for field injection of bimetallic nanoparticles, suggesting that particular care is to be devoted when selecting injection concentration, to avoid porous medium clogging and control the radius of influenc

A large outbreak of COVID-19 in a UK prison, October 2020 to April 2021

Prisons are susceptible to outbreaks. Control measures focusing on isolation and cohorting negatively affect wellbeing. We present an outbreak of coronavirus disease 2019 (COVID-19) in a large male prison in Wales, UK, October 2020 to April 2021, and discuss control measures. We gathered case-information, including demographics, staff-residence postcode, resident cell number, work areas/dates, test results, staff interview dates/notes and resident prison-transfer dates. Epidemiological curves were mapped by prison location. Control measures included isolation (exclusion from work or cell-isolation), cohorting (new admissions and work-area groups), asymptomatic testing (case-finding), removal of communal dining and movement restrictions. Facemask use and enhanced hygiene were already in place. Whole-genome sequencing (WGS) and interviews determined the genetic relationship between cases plausibility of transmission. Of 453 cases, 53% (n = 242) were staff, most aged 25–34 years (11.5% females, 27.15% males) and symptomatic (64%). Crude attack-rate was higher in staff (29%, 95% CI 26–64%) than in residents (12%, 95% CI 9–15%). Whole-genome sequencing can help differentiate multiple introductions from person-to-person transmission in prisons. It should be introduced alongside asymptomatic testing as soon as possible to control prison outbreaks. Timely epidemiological investigation, including data visualisation, allowed dynamic risk assessment and proportionate control measures, minimising the reduction in resident welfare

Transport and deposition of functionalized CdTe nanoparticles in saturated porous media

Comprehensive understanding of the transport and deposition of engineered nanoparticles (NPs) in subsurface is required to assess their potential negative impact on the environment. We studied the deposition behavior of functionalized quantum dot (QD) NPs (CdTe) in different types of sands (Accusand, ultrapure quartz, and iron-coated sand) at various solution ionic strengths (IS). The observed transport behavior in ultrapure quartz and iron-coated sand was consistent with conventional colloid deposition theories. However, our results from the Accusand column showed that deposition was minimal at the lowest IS (1 mM) and increased significantly as the IS increased. The effluent breakthrough occurred with a delay, followed by a rapid rise to the maximum normalized concentration of unity. Negligible deposition in the column packed with ultrapure quartz sand (100 mM) and Accusand (1 mM) rules out the effect of straining and suggests the importance of surface charge heterogeneity in QD deposition in Accusand at higher IS. Data analyses further show that only a small fraction of sand surface area contributed in QD deposition even at the highest IS (100 mM) tested. The observed delay in breakthrough curves of QDs was attributed to the fast diffusive mass transfer rate of QDs from bulk solution to the sand surface and QD mass transfer on the solid phase. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis were used to examine the morphology and elemental composition of sand grains. It was observed that there were regions on the sand covered with layers of clay particles. EDX spectra collected from these regions revealed that Si and Al were the major elements suggesting that the clay particles were kaolinite. Additional batch experiments using gold NPs and SEM analysis were performed and it was observed that the gold NPs were only deposited on clay particles originally on the Accusand surface. After removing the clays from the sand surface, we observed negligible QD deposition even at 100 mM IS. We proposed that nanoscale charge heterogeneities on clay particles on Accusand surface played a key role in QD deposition. It was shown that the value of solution IS determined the extent to which the local heterogeneities participated in particle deposition

Bioaccumulation and ecotoxicity of carbon nanotubes

Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review indicate that CNT do not cross biological barriers readily. When internalized, only a minimal fraction of CNT translocate into organism body compartments. The reported CNT toxicity depends on exposure conditions, model organism, CNT-type, dispersion state and concentration. In the ecotoxicological tests, the aquatic organisms were generally found to be more sensitive than terrestrial organisms. Invertebrates were more sensitive than vertebrates. Single-walled CNT were found to be more toxic than double-/multi-walled CNT. Generally, the effect concentrations documented in literature were above current modeled average environmental concentrations. Measurement data are needed for estimation of environmental no-effect concentrations. Future studies with benchmark materials are needed to generate comparable results. Studies have to include better characterization of the starting materials, of the dispersions and of the biological fate, to obtain better knowledge of the exposure/effect relationships

Gravity-driven transport of three engineered nanomaterials in unsaturated soils and their effects on soil pH and nutrient release

The gravity-driven transport of TiO2, CeO2, and Cu(OH)2 engineered nanomaterials (ENMs) and their effects on soil pH and nutrient release were measured in three unsaturated soils. ENM transport was found to be highly limited in natural soils collected from farmland and grasslands, with the majority of particles being retained in the upper 0-3 cm of the soil profile, while greater transport depth was seen in a commercial potting soil. Physical straining appeared to be the primary mechanism of retention in natural soils as ENMs immediately formed micron-scale aggregates, which was exacerbated by coating particles with Suwannee River natural organic matter (NOM) which promote steric hindrance. Small changes in soil pH were observed in natural soils contaminated with ENMs that were largely independent of ENM type and concentration, but differed from controls. These changes may have been due to enhanced release of naturally present pH-altering ions (Mg(2+), H(+)) in the soil via substitution processes. These results suggest ENMs introduced into soil will likely be highly retained near the source zone

Continuum-based models and concepts for the transport of nanoparticles in saturated porous media: A state-of-the-science review

Environmental applications of nanoparticles (NP) increasingly result in widespread NP distribution within porous media where they are subject to various concurrent transport mechanisms including irreversible deposition, attachment/detachment (equilibrium or kinetic), agglomeration, physical straining, site-blocking, ripening, and size exclusion. Fundamental research in NP transport is typically conducted at small scale, and theoretical mechanistic modeling of particle transport in porous media faces challenges when considering the simultaneous effects of transport mechanisms. Continuum modeling approaches, in contrast, are scalable across various scales ranging from column experiments to aquifer. They have also been able to successfully describe the simultaneous occurrence of various transport mechanisms of NP in porous media such as blocking/straining or agglomeration/deposition/detachment. However, the diversity of model equations developed by different authors and the lack of effective approaches for their validation present obstacles to the successful robust application of these models for describing or predicting NP transport phenomena. This review aims to describe consistently all the important NP transport mechanisms along with their representative mathematical continuum models as found in the current scientific literature. Detailed characterizations of each transport phenomenon in regards to their manifestation in the column experiment outcomes, i.e., breakthrough curve (BTC) and residual concentration profile (RCP), are presented to facilitate future interpretations of BTCs and RCPs. The review highlights two NP transport mechanisms, agglomeration and size exclusion, which are potentially of great importance in controlling the fate and transport of NP in the subsurface media yet have been widely neglected in many existing modeling studies. A critical limitation of the continuum modeling approach is the number of parameters used upon application to larger scales and when a series of transport mechanisms are involved. We investigate the use of simplifying assumptions, such as the equilibrium assumption, in modeling the attachment/detachment mechanisms within a continuum modelling framework. While acknowledging criticisms about the use of this assumption for NP deposition on a mechanistic (process) basis, we found that its use as a description of dynamic deposition behavior in a continuum model yields broadly similar results to those arising from a kinetic model. Furthermore, we show that in two dimensional (2-D) continuum models the modeling efficiency based on the Akaike information criterion (AIC) is enhanced for equilibrium vs kinetic with no significant reduction in model performance. This is because fewer parameters are needed for the equilibrium model compared to the kinetic model. Two major transport regimes are identified in the transport of NP within porous media. The first regime is characterized by higher particle-surface attachment affinity than particle-particle attachment affinity, and operative transport mechanisms of physicochemical filtration, blocking, and physical retention. The second regime is characterized by the domination of particle-particle attachment tendency over particle-surface affinity. In this regime although physicochemical filtration as well as straining may still be operative, ripening is predominant together with agglomeration and further subsequent retention. In both regimes careful assessment of NP fate and transport is necessary since certain combinations of concurrent transport phenomena leading to large migration distances are possible in either case