Mental workload associated with operating an agricultural sprayer: an empirical approach     

Dey AK  Mann DD 《Journal of agricultural safety and health》2011,17(2):91-110

Agricultural spraying involves two major tasks: guiding a sprayer in response to a GPS navigation device, and simultaneous monitoring of rear-attached booms under various illumination and terrain difficulty levels. The aim of the present study was to investigate the effect of illumination, task difficulty, and task level on the mental workload of an individual operating an agricultural sprayer in response to a commercial GPS lightbar, and to explore the sensitivity of the NASA-TLX and SSWAT subjective rating scales in discriminating the subjective experienced workload under various task, illumination, and difficulty levels. Mental workload was measured using performance measures (lateral root mean square error and reaction time), physiological measures (0.1 Hz power of HRV, latency of the P300 component of event-related potential, and eye-glance behavior), and two subjective rating scales (NASA-TLX and SSWAT). Sixteen male university students participated in this experiment, and a fixed-base high-fidelity agricultural tractor simulator was used to create a simulated spraying task. All performance measures, the P300 latency, and subjective rating scales showed a common trend that mental workload increased with the change in illumination from day to night, with task difficulty from low to high, and with task type from single to dual. The 0.1 Hz power of HRV contradicted the performance measures. Eye-glance data showed that under night illumination, participants spent more time looking at the lightbar for guidance information. A similar trend was observed with the change in task type from single to dual. Both subjective rating scales showed a common trend of increasing mental workload with the change in illumination, difficulty, and task levels. However, the SSWAT scale was more sensitive than the NASA-TLX scale. With the change in illumination, difficulty, and task levels, participants spent more mental resources to meet the increased task demand; hence, the illumination, task difficulty, and task level affected the mental workload of an agricultural sprayer operator operating a sprayer in response to a GPS lightbar.  相似文献   

9-cis retinoic acid improves developmental competence and embryo quality during in vitro maturation of bovine oocytes through the inhibition of oocyte tumor necrosis factor-α gene expression     

Deb GK  Dey SR  Bang JI  Cho SJ  Park HC  Lee JG  Kong IK 《Journal of animal science》2011,89(9):2759-2767

Retinoic acid (RA; all-trans RA and 9-cis RA) enhances embryo developmental competence and quality through multiple mechanisms affecting the oocyte and preimplantation embryo. Folliculogenesis and oocyte maturation are influenced by tumor necrosis factor-α (TNF-α) via inhibition of aromatase activity and estradiol secretion in granulosa cells. Retinoic acid inhibits TNF-α production in various cell lines. The aim of the present study was to determine whether oocyte TNF-α concentrations regulate developmental competence and embryo quality and if the beneficial effects of 9-cis RA are mediated through attenuation of oocyte TNF-α production. Bovine cumulus oocyte complexes collected from abattoir ovaries were matured in maturation medium in the absence (control) or presence of 5 nM 9-cis RA (RA), 100 ng/mL of recombinant bovine TNF-α (TNF), or 5 nM 9-cis RA + 100 ng/mL of recombinant bovine TNF-α (RA+TNF). Oocytes were subsequently collected for gene expression analysis or subjected to in vitro fertilization and culture. Apoptosis and gene expression were analyzed in d-8 blastocysts. Results indicated that 9-cis RA downregulated (P < 0.01) both basal and TNF-α-induced TNF-α mRNA in oocytes (1.0-fold in control, 0.4-fold in RA, 2.1-fold in TNF, and 0.7-fold in RA+TNF). The 9-cis RA increased (P < 0.001) blastocyst development rates (37.1 ± 6.9 vs. 23.6 ± 8.0%) and total cell number (138.4 ± 19.2 vs. 120.2 ± 24.5) and reduced (P < 0.001) the percentage of apoptotic cells (3.3 ± 2.0 vs. 5.6 ± 2.3%) compared with controls. Expression of caspase 3 (0.4- vs. 1.0-fold) and TNF-α (0.4- vs. 1.0-fold) mRNA was downregulated (P < 0.05) in RA-treated blastocysts compared with controls. Moreover, 9-cis RA rescued (P < 0.001) development rates (24.5 ± 11.1 vs. 15.6 ± 9.0%), increased total cell number (124.6 ± 36.5 vs. 106.9 ± 31.1), and reduced apoptosis (5.8 ± 2.0 vs. 8.1 ± 3.1%) in blastocysts exposed to TNF-α (TNF group). Caspase 3 (0.8-fold in RA+TNF vs. 2.2-fold in TNF) and TNF-α (0.3-fold in RA+TNF vs. 2.8-fold in TNF) mRNA expression was attenuated (P < 0.05) in TNF-α-treated blastocysts. In conclusion, the present study suggests that 9-cis RA exerts its beneficial roles on oocyte developmental competence and embryo quality by attenuating oocyte TNF-α mRNA expression.  相似文献   

In vivo efficacy of tamarind (Tamarindus indica) fruit extract on experimental fluoride exposure in rats     

Dey S  Swarup D  Saxena A  Dan A 《Research in veterinary science》2011,91(3):422-425

The study was undertaken to determine the efficacy of hydro-methanolic (1:1) extract of tamarind (Tamarindus indica L.) fruit pulp in removing body fluoride burden. Thirty rats were divided into five groups. Keeping no fluoride group as the control, rats of no treatment, low dose, middle dose and high dose groups received sodium fluoride orally at the rate of 200 mg per kg body weight daily for 14 weeks. Rats of low dose, middle dose and high dose group simultaneously received tamarind fruit pulp extract at three doses, viz. 25 (low), 50 (medium) and 100 mg (high) per kg body weight orally, respectively. Fluoride concentration in blood, urine and long bone of experimental rats was monitored to assess the efficacy of the extract. Mean serum fluoride concentration in fluoride exposed rats was 0.145 ± 0.009 and 0.783 ± 0.042 μg/ml on days 0 and 98. In comparison, fluoride concentrations in tamarind treated rats were 0.179 ± 0.021 and 0.633 ± 0.015; 0.179 ± 0.021 and 0.502 ± 0.025 and 0.176 ± 0.021 and 0.498 ± 0.030 μg/ml in low, medium and high dose groups, respectively on day 0 and day 98 of the experiment. There was a significant (p ? 0.01) increase in urinary fluoride excretion from day 28 onwards. The mean fluoride concentration in long bones of treated rats was significantly lower than the values recorded in fluoride exposed rats. These findings suggest that concomitant use of tamarind fruit pulp extract can reduce fluoride concentration in blood and bone and enhanced urinary excretion, indicating the ameliorative potential of fruits of tamarind in fluoride toxicity.  相似文献   

Hyperlipidaemia in trypanosomiasis of naturally infected horses: possible cachexia–anorexia syndrome?     

Muthusamy Ranjithkumar  Tauseef Ahmed Malik  Anju Saxena  Ananya Dan  Pillanatham Civalingam Sakthivel  Sahadeb Dey 《Tropical animal health and production》2013,45(2):417-421

Trypanosomiasis caused by Trypanosoma evansi commonly produces wasting disease with signs of emaciation and cachexia mainly at the end stage. The present study was conducted to explore the possible hyperlipaemia or hyperlipidaemia and its association with cachexia–anorexia in equine trypanosomiasis. Out of the fifteen confirmed animals, none of the plasma sample was opaque. There was a significant increase in plasma triglyceride, total cholesterol and blood urea nitrogen and a highly significant increase in low-density lipoprotein (LDL) levels. A mild increase in high-density lipoprotein (HDL) and very low-density lipoprotein levels were observed, while the relative percentage of HDL and LDL was altered with high significance. A moderate increase in triglyceride and highly significant increase in LDL might be the reasons for retention of appetite and lipolysis. Possible protein breakdown and presence of lipolysis might be the reasons for cachexia in equine trypanosomiasis.  相似文献   

Seroprevalence of bluetongue and presence of viral antigen and type-specific neutralizing antibodies in goats in Tripura,a state at Indo-Bangladesh border of northeastern India     

De  Ankan  Das  Tapan Kumar  Chand  Karam  Debnath  Bikas Chandra  Dey  Saikat  Hemadri  Divakar  Barman  Nagendra Nath  Chaudhary  Jitendra Kumar  Muthuchelvan  Dhanavelu  Saxena  Arpit  Tewari  Neha  Chauhan  Ankita  Lohumi  Ankita  Biswas  Sanchay Kumar 《Tropical animal health and production》2019,51(1):261-265

Tropical Animal Health and Production - Bluetongue (BT) is a notifiable multiple species transboundary viral disease of domestic and wild ruminants. Though the disease is enzootic in India, little...  相似文献   

Mechanical site preparation for forest restoration     

Löf  Magnus  Dey  Daniel C.  Navarro  Rafael M.  Jacobs  Douglass F. 《New Forests》2012,43(5-6):825-848

New Forests - Forest restoration projects have become increasingly common around the world and planting trees is almost always a key component. Low seedling survival and growth may result in...  相似文献   

The pathogenicity of Amidostomum infection in the goose     

K Enigk  H Schanzel  A Dey Hazra 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1969,16(9):784-798

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An observation on the pH changes of haemorrhagic septicaemia alum adjuvant vaccine under different methods of preparation and storage.     

P K Mohapatra  P C Dey  D N Mohanty  S P Kar 《The Indian veterinary journal》1979,56(3):246-247

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Seedborne infection ofAscochyta rabiei in chickpea and its transmission to aerial plant parts     

S. K. Dey  Gurdip Singh 《Phytoparasitica》1994,22(1):31-37

Ascochyta blight of chickpea (Cicer arietinum L.), caused byAscochyta rabiei (Pass.) Labrousse, was found to be both externally as well as internally seedborne in nature, with the external infection being predominant. The pathogen was located primarily on or in the seed coat and in very few cases penetrated into the cotyledons and rarely, to the embryo. Seedling infection resulted from both externally as well as internally seedborne inoculum. The mode of fungal transmission from seed to the foliar plant parts was strictly non-systemic in nature.  相似文献   

Effect of elevated carbon dioxide on growth,nutrient partitioning,and uptake of major nutrients by soybean under varied nitrogen application levels     

Narendra K. Lenka  Sangeeta Lenka  K. K. Singh  Ajay Kumar  Satish B. Aher  Dharmendra Singh Yashona  Pradip Dey  Pawan Kumar Agrawal  A. K. Biswas  Ashok Kumar Patra 《植物养料与土壤学杂志》2019,182(4):509-514

Rising carbon dioxide (CO₂) concentration causes fertilization effects resulting in enhanced crop biomass and yields and thus likely enhances nutrient demand of plants. Hence, this field study was carried out to investigate the effects of elevated CO₂ and N on biomass yield, nutrient partitioning, and uptake of major nutrients by soybean (Glycine max L.) using open‐top chambers (OTCs) of 4 m × 4 m size. Soybean was grown in OTCs under two CO₂ [ambient and elevated (535 ± 36.9 mg L^?1)] and four N levels during July to October 2016. The four N levels were N₀, N₅₀, N₁₀₀, and N₁₅₀ referring to 0, 50, 100, and 150% recommended dose of N. Both CO₂ and N significantly affected biomass and grain yield, though the interaction was non‐significant. CO₂ enrichment produced 30–65% higher biomass and 26–59% higher grain yield under various N levels. As compared to the optimum N application (N₁₀₀), the CO₂‐mediated increment in biomass yield decreased with either lower or higher N application, with the response being lowest at N₁₅₀. As compared to ambient concentration, elevated CO₂ resulted in significant reduction of seed P concentration at all N application levels but at N₁₅₀, an opposite trend was observed. The decrease in seed P was maximum at N₀ and N₅₀ (7–9%) and by 3% at N₁₀₀, whereas there was a gain of 7.5% at N₁₅₀. The seed N and K concentrations were not affected either by CO₂ or N application. Total N, P, and K uptake at harvest were significantly affected by CO₂ and N, but not by CO₂ × N interaction. Elevated CO₂ resulted higher uptake of N by 18–61%, P by 23–62%, and K by 22–62% under various N treatments.  相似文献