Effects of Fertilization On The Growth Dominance of Inland Northwest Forests of The United States

Large trees have disproportionally large competitive advantage in access to light, which has been proposed to increase growth dominance of large trees (e.g., accounting for a larger proportion of growth than volume of a stand). Tree growth may also be limited by the availability of other resources besides light. Nutrient deficiency, especially of nitrogen, is considered common among temperate forests, including mixed-conifer forests of the Inland Northwest of the United States. Data from a long-term forest nutrition study across four Inland Northwest states were analyzed to evaluate nitrogen × potassium fertilization's effects on growth dominance over an eight-year period following treatment in a region of complex forest vegetation types and site conditions. Our results show that growth dominance varied substantially across similar plots in each fertilization treatment, and its mean values generally were at minuscule magnitudes, negative, and not significantly different from zero. We propose that this lack of a clear pattern in growth dominance was the result of the mixed-species composition where shade-tolerant species remained in lower crown positions, yet their relative growth kept pace with large trees. Limited moisture availability at dry sites may have hampered the development of growth dominance. Growth dominance also was lowered by mortality observed among relatively large trees. The largely negative growth dominance across fertilization treatments indicates that small trees maintained higher relative growth rates than large trees, even if absolute growth and size was concentrated in large trees. In the case fertilization does improve stand growth, a significant part of this improved growth will be lost in density-dependent mortality over time if not captured through biomass removals.

Fabrication of Sponges from Amnion Hydrogel to Apply as Wound Dressing

A burn is a type of injury to the skin or other tissues. It can give rise to skin defects or even death. In this study, sponges derived from amnion hydrogel were generated to apply as a wound dressing. The sponges were created by combining crosslinking and freeze-drying methods. There were three types of the obtained sponges: MGA-0 (only washed with PBS), MGA-1 (washed in glycine 1 % for one day) and MGA-2 (washed in glycine 1 % for two days). These sponges were evaluated by scanning electron microscope (SEM), mechanical test, swelling, and cytotoxicity. The tensile strength of the sponges was about 1.8 MPa, and the absorption increased during 24 h. The relative growth rates (%RGR) of MGA-0, MGA-1, and MGA-2 were 88.8, 58.2 and 67.2 %, respectively. The obtained results suggested that the MGA-0 sponge has potential for wound dressing application. HIGHLIGHTS The sponges have been manufactured from human amnion hydrogel by combining crosslinking and freeze-drying methods Through the scanning electron microscope (SEM), the surface of the obtained sponges showed a fibrous-like structure These sponges have good absorbency, the tensile strength of the sponges is about 1.8 MPa like the tensile strength of human skin, and the MGA-0 sponge is not cytotoxic GRAPHICAL ABSTRACT

Growing young catfish (Clarias gariepinus Burchell) with the application of mixed fodders with suspension of chlorella and oilseed crops cake

Aquaculture is based on the use of compound feed, which accounts for about 70–80% of costs. Due to their biological needs, metabolic characteristics and habitat, fish are more demanding on the quality of feed, the main suppliers of which in the Republic of Belarus are foreign firms. This leads to an increase in the cost of production and significantly hinders the development of aquaculture, therefore, when developing formulations of domestic mixed feeds for juvenile fish of valuable species, it is necessary to rely on the use of inexpensive, affordable and effective components. In the aquaculture of Belarus, one of the promising species for industrial production is the African catfish (Clarias gariepinus Burchell). High food plasticity makes it possible to grow it under industrial conditions, for example, in recirculating water systems, on the same artificial feed. It is known that the addition of algae to feed contributes to the normalization of metabolic processes in fish, accelerates the growth of natural beneficial microflora during digestion and strengthens the body’s immune system. On the basis of this, experimental compound feeds for juvenile African catfish were developed with the addition of chlorella, rapeseed cake and dyeing safflower to the suspension. A chemical analysis of the experimental and control feed was carried out, which revealed the ability of the developed feed to meet the needs of fish in basic nutrients on a par with the control feed. The results of growing African catfish using an experimental compound feed (KS + 3% rapeseed + 3% safflower + 3% chlorella suspension) indicated an increase in absolute and relative growth rates, as well as a decrease in the feed ratio, which made it possible to obtain the best economic effect among the applied compound feeds. This indicated the possibility of effective use of the developed compound feed with the addition of a suspension of chlorella and rapeseed and dyeing safflower cake as a full-fledged replacement for imported compound feed.

Fitness cost of vancomycin-resistant Enterococcus faecium plasmids associated with hospital infection outbreaks

Background Vancomycin resistance is mostly associated with Enterococcus faecium due to Tn1546-vanA located on narrow- and broad-host plasmids of various families. This study’s aim was to analyse the effects of acquiring Tn1546-carrying plasmids with proven epidemicity in different bacterial host backgrounds. Methods Widespread Tn1546-carrying plasmids of different families RepA_N (n = 5), Inc18 (n = 4) and/or pHTβ (n = 1), and prototype plasmids RepA_N (pRUM) and Inc18 (pRE25, pIP501) were analysed. Plasmid transferability and fitness cost were assessed using E. faecium (GE1, 64/3) and Enterococcus faecalis (JH2-2/FA202/UV202) recipient strains. Growth curves (Bioscreen C) and Relative Growth Rates were obtained in the presence/absence of vancomycin. Plasmid stability was analysed (300 generations). WGS (Illumina-MiSeq) of non-evolved and evolved strains (GE1/64/3 transconjugants, n = 49) was performed. SNP calling (Breseq software) of non-evolved strains was used for comparison. Results All plasmids were successfully transferred to different E. faecium clonal backgrounds. Most Tn1546-carrying plasmids and Inc18 and RepA_N prototypes reduced host fitness (–2% to 18%) while the cost of Tn1546 expression varied according to the Tn1546-variant and the recipient strain (9%–49%). Stability of Tn1546-carrying plasmids was documented in all cases, often with loss of phenotypic resistance and/or partial plasmid deletions. SNPs and/or indels associated with essential bacterial functions were observed on the chromosome of evolved strains, some of them linked to increased fitness. Conclusions The stability of E. faecium Tn1546-carrying plasmids in the absence of selective pressure and the high intra-species conjugation rates might explain the persistence of vancomycin resistance in E. faecium populations despite the significant burden they might impose on bacterial host strains.

Effect of regulated deficit irrigation (RDI) on the vegetative growth of pear variety Triunfo de Viena (Pyrus communis L.)

One of the consequences of a water deficit in the vegetative growth is the modification of the plant vigor, which determines the extent and the rate of growth and lengthening in shoots, which, in this phase, is more important than fruit growth, which is very slow in terms of dry mass accumulation. The objective of this research was to determine the effect on the vegetative growth of the pear variety Triunfo de Viena (Pyrus communis L) of regulated deficit irrigation (RDI), which was compared with a control irrigated at 100% crop evapotranspiration (ETc). The irrigation treatments consisted of the application of watering regimes of 74 and 48% ETc in treatment T2 and 60 and 27% ETc in treatment T3 in 2014 and 2015, respectively, during the period of rapid fruit growth with the same watering regime used in T1 (control) applied during the rest of the season. The irrigation reduction used in T2 and T3 represented water savings of 26% and 40% in 2014 and 52% and 73% in 2015, respectively. In the deficit treatments, there were no significant differences with respect to the control for the length, or absolute and relative growth rates (AGR and RGR) of the shoots. The weight of the wood from the fructification pruning had a significant difference between T3 and the control.

Production Potential of Allelopathic Rice, Cymbopogon, Desmodium, Mucuna and Maize

Allelochemicals regulate the productivity of crop ecosystems. A screen house experiment was conducted (2016) at the National Crops Resources Research Institute, Namulonge, Uganda to determine the effects of NERICA 1 rice (an interspecific hybrid between Oryza sativa and O. glaberrima species), Cymbopogon nardus (C), Desmodium uncinatum (D), Mucuna pruriens (Mc) and LONGE 6H, Zea mays (Mz) on crop relative growth rates (RGR), nitrogen (N), phosphorus (P) and potassium (K) nutrient levels. One field study was conducted on a farm (2017) to establish the allelopathic interactive effects of RCDMcMz on Striga hermonthica (a parasitic weed), crop competition and productivity. Data was collected on striga, RMz growth, nutrient levels and yield. Potted rice reduced (30%-47%) in root length but Mz leaf length increased (31% & 15%) with Mc & D. RMc reduced (73%) striga and increased rice RGR (14-42 days). RD similarly reduced (67%) striga. RC increased (96%, 44% & 73%) rice NPK uptake, RGR (14-42 days), reduced (57%) striga and increased (1.56) the combined land equivalent ratio (CLER) and rice grain yields. RMz reduced (16%, 38% & 38%) rice NPK reserves, RGR (14-42 days), CLER (1.0), grain yields and increased (36%) striga. RD recorded higher CLER (1.56). MzMc reduced (15% & 27%) maize P uptake and NP uptake increased (42% & 9.3%) under MzC & MzD (73% & 29%). RMc increased rice RGR (14-42 days). Maize RGR (14-28 days) increased under MzD, MzMc & MzC and reduced (28-42 days) under MzD, RC & MzMc.. The ecosystems’ productivity was attributed to allelopathy.

Effects of soil amendments on leaf anatomical characteristics of marigolds cultivated in cadmium-spiked soils

The marigolds (Tagetes spp.) in this study were classified as excluders for cadmium (Cd); however, their leaves also accumulated substantial Cd content. Among the experimental treatments (i.e., control, cattle manure, pig manure, and leonardite which served as soil amendments), pig manure resulted in significantly increased growth performance for all marigold cultivars as seen by relative growth rates (119–132.3%) and showed positive effects on leaf anatomy modifications, e.g., thickness of spongy and palisade mesophyll, size of vein area and diameter of xylem cells. This may be due to substantially higher essential nutrient content, e.g., total nitrogen (N) and extractable phosphorus (P), in pig manure that aided all marigold cultivars, particularly the French cultivar which exhibited the highest relative growth rate (132.3%). In the Cd-only treatment, cell disorganization was observed in vascular bundles as well as in palisade and spongy mesophyll, which may have been responsible for the lowest plant growth performance recorded in this study, particularly among the American and Honey cultivars (RGR = 73% and 77.3%, respectively).

Spatiotemporal invasion dynamics of SARS-CoV-2 lineage B.1.1.7 emergence

Understanding the causes and consequences of the emergence of SARS-CoV-2 variants of concern is crucial to pandemic control yet difficult to achieve, as they arise in the context of variable human behavior and immunity. We investigate the spatial invasion dynamics of lineage B.1.1.7 by jointly analyzing UK human mobility, virus genomes, and community-based PCR data. We identify a multi-stage spatial invasion process in which early B.1.1.7 growth rates were associated with mobility and asymmetric lineage export from a dominant source location, enhancing the effects of B.1.1.7’s increased intrinsic transmissibility. We further explore how B.1.1.7 spread was shaped by non-pharmaceutical interventions and spatial variation in previous attack rates. Our findings show that careful accounting of the behavioral and epidemiological context within which variants of concern emerge is necessary to interpret correctly their observed relative growth rates.

Characterization of resistance and fitness cost of Descurainia sophia L. populations from Henan and Xinjiang, China

Descurainia sophia L. is a notorious weed in winter wheat field and has serious resistance to tribenuron-methyl. Xinjiang is a main wheat production region in China with no information on D. sophia resistance to tribenuron-methyl. Here, resistance levels of D. sophia populations to tribenuron-methyl from Xinjiang and Henan were investigated. In addition, homozygous mutation subpopulations of high resistant D. sophia populations from Xinjiang and Henan were generated and then cross-resistance and fitness cost were determined. Results showed that 5 out of 31 populations from Xinjiang developed resistance to tribenuron-methyl, including two high resistant populations (X30 and X31). While 10 out of 11 populations from Henan showed resistance to tribenuron-methyl, including three high resistant populations (H5, H6 and H7). X30 and X31 shared the same mutation type of Pro197Thr in ALS1, while the mutation type of ALS1 in H5, H6 and H7 were Pro197Ser, Pro197His and Pro197Ala, respectively. The homozygous mutation subpopulations (SX30, SX31, SH5, SH6, SH7) showed cross-resistance to flucarbazone-sodium, bensulfuron methyl and flumetsulam. Under monoculture condition, relative growth rates of SX30, SX31 were higher than susceptible population (SX13), while that in SH5, SH6, SH7 were almost same with SX13. When mix planted with SX13, SX30 and SX31 displayed weaker competitiveness than SX13, while SH5, SH6, SH7 showed stronger competitiveness than SX13. The results suggested that D. sophia from Xinjiang had low resistance frequency to tribenuron-methyl and the high resistant populations had fitness costs.

Effects of dissolved oxygen concentrations on growth, survival and gonadal development of freshwater pearl mussel Lamellidens marginalis

The present study was conducted to evaluate the effects of dissolved oxygen concentrations on growth, survival and gonadal development of freshwater pearl mussel (Lamellidens marginalis). Twenty adult L. marginalis were exposed to each of the five different concentrations of dissolved oxygen (DO) i.e (T0, no aeration), and T1, T2, T3 and T4 with one, two, three and four air stone aerators, respectively in fifteen glass aquaria each containing 10L of pond water. DO concentrations were significantly higher in all the treatments compared to the control but there were no significant differences among the treatments. There were significant differences in the growth and survival rates between control and treatments. The relative growth rates (%) were significantly higher in the highest oxygen concentration (T4) compared to other treatments. The survival rate was zero in control (T0), whereas it was 66.67%, 70.00%, 71.67% and 73.33%, respectively for T1, T2, T3 and T4. On day-30, oocytes in T0 were found to be smaller in size, with developing acini and no previtellogenic oocytes; whereas in T1, T2, T3 and T4, previtellogenic oocytes and larger acini were evident. On day-60, vitellogenic oocytes along with few under-developed oocytes started to detach from the acini walls, as well as some already started migration to germinal duct on day-90. This indicates that ovaries of all the treatments were ripe and were ready to spawn between day-60 and -90. On day-30, secondary spermatocytes were observed in testicular acini in case of T0, whereas more developed and dense spermatids were evident in T1, T2, T3 and T4. These results indicate that testes were in late development stages in T0, whereas they were ripe in all the treatments. The current findings indicate that hypoxia slows down growth, reduces survival rate and retards development of reproductive organs in L. marginalis.