Confirmed resistance to aryloxyphenoxypropionate herbicides in Phalaris minor populations in Iran

Phalaris minor (littleseed canary grass) is a major weed in wheat fields in some parts of Iran. Diclofop‐methyl, fenoxaprop‐P‐ethyl, and clodinafop‐propargyl are three acetyl coenzyme A carboxylase (ACCase)‐inhibiting herbicides that are commonly used to control this grass in wheat fields. Thirty‐four P. minor populations with suspected resistance to ACCase‐inhibiting herbicides were sampled from wheat fields in the provinces of Fars and Golestan in Iran. The dose–response assays that were conducted under controlled greenhouse conditions indicated that 14 populations were resistant to fenoxaprop‐P‐ethyl, seven populations were resistant to both fenoxaprop‐P‐ethyl and diclofop‐methyl, and three populations were resistant to fenoxaprop‐P‐ethyl, diclofop‐methyl, and clodinafop‐propargyl. These populations showed different levels of resistance to the applied herbicides, compared to the susceptible population. These results suggest that different mechanisms of resistance could be involved. The enzyme assay revealed that the existence of modified ACCase in the three most‐resistant populations (AR, MR4, and SR3) is responsible for the resistance of these populations.     

Sum rules and interlayer conductivity of high-Tc cuprates

Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition.     

Breeding for pre-harvest sprouting resistance in bread wheat under rainfed conditions

Pre-harvest sprouting in wheat is the germination of seeds within the spikes when rains occur after or during grain ripening, which occurs commonly in the barani tract of Pakistan. Therefore, 10 cultivars and five advanced lines of spring bread wheat were evaluated for pre-harvest sprouting resistance. After natural rainfall, seeds were immediately collected from the wet spikes and tested for germinating ability. Three different germination tests were applied to hand-threshed seed: (1) spikes threshed on the day of sampling and germination tested immediately, (2) spikes threshed on the day of sampling and germination tested 1 week later, and (3) spikes threshed 1 week after sampling and germination test immediately after threshing. Seeds and spikes kept for 1 week were place on blotting paper at room temperature. Cultivars BARS-09, 09FJ17, Doukkala-12, NARC-09 and Ouassou-20 exhibited higher sprouting resistance while other genotypes were susceptible to pre-harvest sprouting in each of the three tests. A diallel crossing was conducted with six susceptible and two resistant genotypes to assess the genetic behavior of pre-harvest sprouting resistance. The combining ability (CA) demonstrated a higher proportion of additive genetic effects for sprouting resistance, because of higher variance of general and specific CA for both parameters under study. Doukkala-12 and BARS-09 showed increased pre-harvest sprouting resistance in their F₁ descendants.     

Numerical investigation on self-priming process of self-priming pump

In order to investigate the self-priming process of self-priming pump, an unsteady simulation was conducted where the Navier-Stokes equations were used with the Lagrangian-Eularian model. In course of this investigation, the volume fractions, pressure distribution and self-priming time were carried out. By analyzing the volume, velocity and pressure distribution of the gas-liquid two-phase flow at different time, the two-phase content via the variation law of the two-phase flow in the pump was carried out. By monitoring and analyzing the gas-liquid flow at the outlet of the pump, the self-priming time and crucial periods were given. Two phenomena were mainly characterized by the self-priming process such as the gas-liquid mixing and separation, which occur in the early stage of self-priming process. During that period the gas-liquid mixing clouds appear on the outer edge of the impeller, and the instantaneous void fraction at the inlet and outlet of the impeller decreases obviously. It was also established from the transient study that the effects of gas have a major influence on the hydraulic performance of the pump at the early stage of operation. To increase the usage of self-priming pump and to also understand the energy conversion of the pump it is very essential to investigate and establish the basic working principle of the self-priming pump.     

Precision phenotyping of contrasting potato(Solanum tuberosum L.) varieties in a novel aeroponics system for improving nitrogen use efficiency: In search of key traits and genes

With increasing population, degrading soil health, limited arable land area, and high cost of nitrogen(N) fertilizers, improving nitrogen use efficiency(NUE) of potato is an inevitable approach to save the environment and achieve sufficient tuber yields with less N fertilizer supply. Recently, we have developed an aeroponics system to study NUE in potato using genomics, physiology, and breeding approaches. This study aims on precision phenotyping of plants of two distinct potato varieties(Kufri Gaurav, N efficient; Kufri Jyoti, N inefficient) in the novel aeroponics system. Plants were grown in aeroponics under controlled conditions with low N(0.75 mmol L~(-1) NO_3~-) and high N(7.5 mmol L~(–1) NO_3~-) levels. Plant biomass, root traits, total chlorophyll content, and plant N were increased with increasing N supply, whereas higher NUE parameters namely NUE, agronomic NUE(Ag NUE), N uptake efficiency(NUp E), harvest index(HI), and N harvest index(NHI) were observed at low N. An NUE efficient cv. Kufri Gaurav showed higher tuber dry weight, fresh tuber yield, tuber number per plant, early start of tuber harvesting, root traits, stolon traits, NUE parameters, and higher amino acid(aspartic acid and asparagine) content at low N supply. Higher expression of nitrate reductase(NR), nitrite reductase(NIR), and asparagine synthetase(AS) genes was observed in the leaf tissues of Kufri Gaurav at high N. Thus, aeroponics-based precision phenotyping enables identification of NUE efficient genotypes based on key traits and genes involved in improving NUE in potato. Further, this study suggests that the potential of aeroponics can be utilized to investigate N biology in potato under different N regimes.     

Chlamydial infection in a colony of captive koalas

Forty three koalas in a captive colony were investigated for the presence of Chlamydia psittaci infection and associated disease. Swabs were taken from conjunctivae and urogenital sites for cell culture isolation of C psittaci and for cytological examination (direct smears) for chlamydial inclusions and evidence of inflammation. On the basis of cell culture isolation, 28 samples from 25 koalas were positive for C psittaci (that is, infected). Three koalas were positive from both sites, 5 from conjunctivae alone and 17 from urogenital sites alone. Seven of the 8 koalas with positive conjunctival swabs had overt signs of conjunctivitis, but only 3 of the 20 koalas with positive urogenital swabs had overt signs of 'wet bottom' (continual urine soiling due to cystitis) or purulent discharge. However, 5 of the 20 with positive urogenital swabs had past episodes of 'wet bottom'. Moreover, examination of direct cytological smears showed evidence of inflammation (neutrophils) in 7 of 8 koalas with positive conjunctival swabs and 17 of 20 with positive urogenital swabs. Chlamydial inclusions were rarely identified with surety on direct cytological smears. In the 18 koalas without chlamydia, one had overt conjunctivitis while 2 had past episodes of conjunctivitis. The koala with conjunctivitis at the time of sampling had a prior history of 'wet bottom'. Examination of direct cytological smears revealed 2 of the chlamydial negative koalas had high numbers of neutrophils in urogenital smears. It was concluded that C psittaci infection may cause overt or sub-clinical disease, with the former developing when the koalas were stressed through management procedures or concomitant disease.     

Assessment of dry matter and protein digestibilities of selected raw ingredients by discus fish (Symphysodonaequifasciata) using in vivo and in vitro methods

The reliability of several in vitro steps as compared with the conventional in vivo method to determine the dry matter and protein digestibilities of several raw ingredient by discus juveniles was assessed. In vitro studies were conducted based on a 12-h digestion method and measurement of pH drop involving four different substrate–enzyme mixtures, namely the Lazo single enzyme, Hsu multi-enzyme, Saterlee multi-enzyme and discus extract enzyme system. Results from both methods showed that fishmeal was highly digestible in terms of dry matter (67.22–87.52%) and protein (76.8–91.18%). With the exception of poultry offal meal, findings also indicate that discus digests dry matter in feedstuffs of animal origin (fish meal and beef heart) more efficiently compared with plant materials (soybean and wheat meal) with no obvious trend observed for protein digestibility in any of the ingredients tested. Apparent digestibility coefficients of not less than 40% suggest that all the ingredients tested were potential ingredients for development of formulated feed for discus culture. A comparison between the different in vitro enzyme systems tested showed that the Saterlee method, which used commercial mammalian and bacterial enzymes, was best in terms of its ability to differentiate the digestibilities of the various ingredients and correlation ( r ²=0.85–0.90) with the in vivo results. The use of a crude enzyme extract from discus digestive tract also provided values consistent with in vivo and Saterlee in vitro methods ( r ²=0.72–0.87), indicating the potential and need for further investigation to develop a more accurate in vitro assay based on discus digestive enzymes.     

The effect of level of feed intake on the pharmacokinetic disposition and efficacy of ivermectin in sheep

The kinetic disposition of orally administered [³H]-Ivermectin (IVM) was examined in sheep in which the feed intake was maintained at either 800 or 400 g/day. The [³H]-metabolites were almost completely associated with particulate digesta in the rumen. In the low feed intake group the digesta flow was slower than in sheep on high feed intake. This resulted in an extended residence time and greater availability of IVM and its metabolites. The anthelmintic efficacy of IVM was then examined in sheep in which feed intake was reduced from 800 g/day to 400g/36h prior to and 36 h after IVM administration. In sheep with reduced intake 97% of IVM-resistant Haemonchus contortus were removed, compared with 53% in sheep maintained on high feed intake.