Late defoliation and wheat yield: Little evidence of post-anthesis source limitation

The effect of source reduction on yield and protein content of bread wheat under well-watered and mild drought stress condition in a semi-arid climate was studied. Field experiments were conducted at the Tehran University research farm during 2003–2004 and 2004–2005 growing seasons. Mild drought stress was imposed when plants were at the second node stage by repeatedly withholding watering and re-irrigating when they showed symptoms of wilting or leaf rolling. Partial defoliations (all leaf lamina other than flag leaves were removed) were imposed at booting and anthesis; complete defoliation was imposed at anthesis (defoliation treatments were applied to all plants of each plot). Drought stress caused a significant increase in the remobilization of pre-anthesis reserves to the grain. Defoliation did not significantly affect remobilization. Grain yield and 1000-grain weight was reduced slightly by drought stress, but in most cases it was not significantly reduced by defoliation. Significant changes were not observed for grain protein content between defoliated and control plots. The results suggested that grain yield of the cultivar used under the condition tested is more controlled by sink than source strength.     

Effects of hypertonic dextrose and paraffin solution as non‐antibiotic treatments of clinical endometritis on reproductive performance of high producing dairy cows

The objective of this study was to compare the reproductive performance of cows affected by clinical endometritis (CE) following treatment with an intrauterine infusion of 50% dextrose solutions (DEX) and liquid paraffin (LP) as alternative therapies with routine treatments including PGF_2α injection and intrauterine infusion of oxytetracycline (OTC). Moreover, the reproductive indices of cows treated with endometritis were compared with those of healthy ones. At postpartum reproductive tract examination (28–35 DIM) in one Iranian dairy farm, cows with CE without any selection were assigned to four groups: (a) OTC, a common treatment in Iran, was administered (5 g) to 396 cows, (b) PGF₂α (PG) was injected to 496 cows, (c) dextrose solution (DEX): intrauterine infusion of 50% dextrose solution (200 ml) was done in 427 cows, and (d) liquid paraffin (LP) was administered (100 ml) to 423 cows via intrauterine route. We further assigned 2,233 clinically healthy cows to the control group. The incidence of endometritis was 41.6% in this study. Based on the results of reproductive indices including median days to first AI, days open (DO), first service conception rate, conception rate in 2nd and 3rd services, conception rate in all three services, pregnancy rate < 100 days and pregnancy rate < 200 days, except for median days to first AI in other reproductive indexes, reproductive performance was significantly lower in LP group compared with the healthy cows and other treatment groups (p < 0.05). Except for the first service conception rate and proportion of cows pregnant before 100 days in milk (DIM), there existed no significant difference between the DEX group and the control as far as reproductive performance is concerned (p ≥ 0.05). The first service conception rate was recognizably lower in DEX group compared with OTC and PG (p < 0.05). In conclusion, the use of a non‐antibiotic special solution of dextrose 50% is a good alternative to antibiotic agents concerning the treatment of CE in dairy cows.     

Gene expression profiling in embryonic chicken ovary during asymmetric development

The reproductive system in female birds arises as bilateral asymmetrical anlagen, excluding the birds of prey. Earlier, histological and messenger RNA (mRNA) expression profile studies of several genes related to gonadal sex differentiation in chicken embryos tried to elucidate the query of this asymmetry in a scattered manner. To understand the matter precisely, we have focused on mRNA expression of a cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) in second half of the embryonic days (E10–E18). The established role of leptin in development of the embryo and its expression in the embryonic ovary also drove us to check leptin receptor (LEPR) expression in the ovary. Increased expression of FSHR and CYP19A1 in the left ovary compared with that in the right ovary was identified (P < 0.05), promoting preferential left ovarian development and functionality. Significant high expression (P < 0.05) of the apoptotic genes in the right ovary were also involved here. Leptin probably has no direct influence on ovarian asymmetry as no significant variation in gonadal mRNA expression of LEPR was observed within the same experimental days. We propose that asymmetric expression of this cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) leads to the development of dimorphic gonads during embryogenesis.     

Growth Properties and Ion Distribution in Different Tissues of Bread Wheat Genotypes (Triticum aestivum L.) Differing in Salt Tolerance

Four bread wheat genotypes differing in salt tolerance were selected to evaluate ion distribution and growth responses with increasing salinity. Salinity was applied when the leaf 4 was fully expanded. Sodium (Na⁺), potassium (K⁺) concentrations and K⁺/Na⁺ ratio in different tissues including root, leaf‐3 blade, flag leaf sheath and flag leaf blade at three salinity levels (0, 100 and 200 mm NaCl), and also the effects of salinity on growth rate, shoot biomass and grain yield were evaluated. Salt‐tolerant genotypes (Karchia‐65 and Roshan) showed higher growth rate, grain yield and shoot biomass than salt‐sensitive ones (Qods and Shiraz). Growth rate was reduced severely in the first period (1–10 days) after salt commencements. It seems after 20 days, the major effect of salinity on shoot biomass and grain yield was due to the osmotic effect of salt, not due to Na⁺‐specific effects within the plant. Grain yield loss in salt‐tolerant genotypes was due to the decline in grain size, but the grain yield loss in salt‐sensitive ones was due to decline in grain number. Salt‐tolerant genotypes sequestered higher amounts of Na⁺ concentration in root and flag leaf sheath and maintained lower Na⁺ concentration with higher K⁺/Na⁺ ratios in flag leaf blade. This ion partitioning may be contributing to the improved salt tolerance of genotypes.     

Simulating Escherichia coli O157:H7 transmission to assess effectiveness of interventions in Dutch dairy-beef slaughterhouses

Beef contamination with Escherichia coli O157:H7 (VTEC) is an important food-safety issue. To investigate the effectiveness of interventions against VTEC in Dutch beef industrial slaughterhouses that slaughter 500 dairy cattle per day, a Monte Carlo simulation model was built. We examined seven carcass-antimicrobial interventions, namely: hot-water wash, lactic-acid rinse, trim, steam-vacuum, steam-pasteurization, hide-wash with ethanol and gamma irradiation, and their combinations. The estimated daily prevalence of contaminated beef-carcass quarters as the output of the model was 9.2%. Contaminated was defined as containing one or more CFU on the surface of a carcass quarter at the end of the quartering stage. Single interventions (except irradiation) could reduce the prevalence to from 6.2% to 1.7%, whereas the combination of interventions could lower it to from 1.2% to 0.1%. The most powerful intervention was irradiation, which could reduce the prevalence to <0.1%. The results of this study indicate that application of single interventions might be useful, although not sufficient. Hence, a combination of interventions along the slaughter process is the more promising approach to reduce the prevalence of contaminated beef quarters.     

Marine-Derived Indole Alkaloids and Their Biological and Pharmacological Activities

Novel secondary metabolites from marine macroorganisms and marine-derived microorganisms have been intensively investigated in the last few decades. Several classes of compounds, especially indole alkaloids, have been a target for evaluating biological and pharmacological activities. As one of the most promising classes of compounds, indole alkaloids possess not only intriguing structural features but also a wide range of biological/pharmacological activities including antimicrobial, anti-inflammatory, anticancer, antidiabetic, and antiparasitic activities. This review reports the indole alkaloids isolated during the period of 2016–2021 and their relevant biological/pharmacological activities. The marine-derived indole alkaloids reported from 2016 to 2021 were collected from various scientific databases. A total of 186 indole alkaloids from various marine organisms including fungi, bacteria, sponges, bryozoans, mangroves, and algae, are described. Despite the described bioactivities, further evaluation including their mechanisms of action and biological targets is needed to determine which of these indole alkaloids are worth studying to obtain lead compounds for the development of new drugs.     

Spatial association between primary Middle East respiratory syndrome coronavirus infection and exposure to dromedary camels in Saudi Arabia

Middle East respiratory syndrome coronavirus (MERS‐CoV) is an emerging zoonotic disease. Exposure to dromedary camels (Camelus dromedaries) has been consistently considered the main source of primary human infection. Although Saudi Arabia reports the highest rate of human MERS‐CoV infection and has one of the largest populations of dromedary camels worldwide, their spatial association has not yet been investigated. Thus, this study aimed to examine the correlation between the spatial distribution of primary MERS‐CoV cases with or without a history of camel exposure reported between 2012 and 2019 and dromedary camels at the provincial level in Saudi Arabia. In most provinces, a high proportion of older men develop infections after exposure to camels. Primary human infections during spring and winter were highest in provinces characterized by seasonal breeding and calving, increased camel mobilization and camel–human interactions. A strong and significant association was found between the total number of dromedary camels and the numbers of primary camel‐exposed and non‐exposed MERS‐CoV cases. Furthermore, spatial correlations between MERS‐CoV cases and camel sex, age and dairy status were significant. Via a cluster analysis, we identified Riyadh, Makkah and Eastern provinces as having the most primary MERS‐CoV cases and the highest number of camels. Transmission of MERS‐CoV from camels to humans occurs in most primary cases, but there is still a high proportion of primary infections with an ambiguous link to camels. The results from this study include significant correlations between primary MERS‐CoV cases and camel populations in all provinces, regardless of camel exposure history. This supports the hypothesis of the role of an asymptomatic human carrier or, less likely, an unknown animal host that has direct contact with both infected camels and humans. In this study, we performed a preliminary risk assessment of prioritization measures to control the transmission of infection from camels to humans.     

Evaluation of the efficiency of TaqMan duplex real-time PCR assay for non-invasive pre-natal assessment of foetal sex in equine

Accurate diagnosis of foetal sex in pregnant mare is helpful for many breeders, both for private or commercial purposes. In this study, in order to pre-natal foetal sexing in equine, we used TaqMan duplex real-time PCR to detect the specific regions of SRY and TSPY genes on extracted cell-free foetal DNA from maternal blood. Peripheral blood samples from 50 pregnant Arabian mares with singleton foetuses were collected. Cell-free foetal DNA was extracted from maternal plasma, and duplex real-time PCR assays were performed with TaqMan probes and primers. Amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as control of DNA extraction procedure. From the 50 sampled mares, 28 cases had female and 22 mares had male foetuses. The final results for 46 samples were conclusive, and from them, 43 cases were predicted correctly. Sensitivity, specificity and accuracy of the test were 90.48%, 96% and 93.48%, respectively. In conclusion, a TaqMan duplex real-time PCR was set up to pre-natal detection of foetal sex in equine. The method was fast and decreased the false-positive and false-negative results. The technique can be used as a routine procedure in farms by collecting only a blood sample.     

Effects of irrigation strategies and soils on field grown potatoes: Root distribution

Root distribution of field grown potatoes (cv. Folva) was studied in 4.32 m² lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm root per cm³ soil) compared with root development in fully irrigated (FI) potatoes. Highest RLD existed in the top 30-40 cm of the ridge below which it decreased sharply. The RLD was distributed homogenously along the ridge and furrow but heterogeneously across the ridge and furrow with highest root density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30-70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below the furrows compared with the corresponding layers below the ridges. The RLD values in the soil profile of the ridges and the furrows followed the Gerwitz and Page model: RLD = α × exp(−β × z). The highest value of surface root density (α) and rate of change in density (β) was found in coarse sand while the lowest values of α and β were found in the sandy loam and loamy sand. The model estimated the effective rooting depth in coarse sand and sandy loam quite well but did slightly overestimate it in the loamy sand. Statistical analysis showed that one α and β value can be used for each soil irrespective of the irrigation treatment. Thus, the effective rooting depths corresponding to root length densities of 0.1 and 0.25 cm cm⁻³ for sandy loam, loamy sand, and coarse sand soils were 99, 141, and 94 cm, and 80, 115, and 78 cm, respectively, calculated from top of the ridge. The findings of this study can be used in practice for efficient use of water and nutrients in the field.     

Effect of Schlafen 2 on natural killer and T cell development from common T/natural killer progenitors

Natural Killer (NK) cells are thought to develop from common lymphoid progenitors in the bone marrow. Even though thymus is not essential for NK cell development, T-cell/natural killer-cell (T/NK) precursors, DN1 (CD44+CD25-) and DN2 (CD44+CD25+) when cultured on an OP9 stroma, give rise to some NK1.1 cells. Genes of the Schlafen (Slfn) family are involved in hematopoietic and immune processes. The contribution of the Slfn genes in NK cell development from Double Negative (DN) cells is unknown. We transduced DN1 and DN2 progenitors prepared from C57BL/6 (B6) mouse thymus with Schlafen 1 (Slfnl) and Schlafen 2 (Slfn2) genes using Mig retroviral vector containing the Green Fluorescent Protein (GFP) gene and cultured those transduced progenitors on OP9 and OP9 stroma expressing the Notch ligand Delta-like 1 (OP9-DL 1) with appropriate cytokines to see if they affect generating NK and T-cells differently. Maturation of both NK and T cells from immature T/NK thymocytes hampered by Slfn1 and Slfn2 transduction but we got a small number of Slfn1 and Slfn2 expressing cells upon culture of transduced DN progenitors on stroma cells. There was no difference between Slfn1 expressing (GFP+) and none expressing T cells regarding CD3 expression but all mature NK cells were from Slfn1 negative population. Slfn2 completely blocked maturation of T cells but there was no difference between Slfn2 expressing and none expressing NK cells. Based on our findings both Slfn1 and Slfn2 interfere with maturation of DN2 progenitors but T cell development is more sensitive to Slfn2 expression than NK cell.