Controlled Environmental Conditions Research Articles

Examination of Horizontal Transmission of Nippostrongylus brasiliensis in Mice to Assess Biosecurity Risks.

Mice are commonly infected with Nippostrongylus brasiliensis (Nb) to study their immune responses. However, biosecurity measures have not been established for housing Nb-infected mice and rats. Transmission reportedly does not occur when infected mice are cohoused with naive mice. To test this, we inoculated female NOD. Cg-Prkdcscid Il2rgtm1Wjl /Sz(NSG;n = 12) and C57BL/6J (B6;n = 12) mice with 750 Nb L₃ larvae. These mice were then cohoused with naïve NSG ( n = 24) and B6 ( n = 24) mice (1 infected and 2 naïve mice per cage (24 cages) for 28 d in static microisolation cages that were changed every 14 d. We also did several studies to determine the conditions that favor horizontal transmission. First, we assessed in vitro development to the L₃ stage of Nb egg-containing fecal pellets maintained under 4 environmental conditions (dry, moist, soiled bedding, and control). Second, we assessed infection of naïve NSG mice ( n = 9) housed in microisolation cages that contained soiled bedding spiked with infective L₃ larvae (10,000/cage). Third, we gavaged NSG mice ( n = 3) with Nb eggs to model the potential for infection after coprophagy. We found that naïve NSG (9 of 24) and B6 (10 of 24) mice cohoused with an infected cagemate passed Nb eggs in feces as early as 1 d after cohousing and intermittently thereafter for varying periods. This shedding was presumably the result of coprophagy because adult worms were not detected in the shedding mice at euthanasia. Although eggs developed in vitro into L₃ larvae under moist and control environmental conditions, none of the NSG mice housed in cages with L₃ -spiked bedding or gavaged with eggs became infected with Nb. These findings indicate that infectious horizontal transmission does not occur when mice are housed with Nb-shedding cage mates in static microisolation cages with a 14-d cage-changing interval. Results from this study can be used to inform biosecurity practices when working with Nb-infected mice.

Detection of combined frost and drought stress in wheat using hyperspectral and chlorophyll fluorescence imaging

Immediate detection and prediction tools for interactive stresses are essential to avoid yield losses. This study investigated the capability of hyperspectral (HSI) and chlorophyll fluorescence imaging (CFI) to characterize individual and interactive frost (−4 °C) and drought (40% soil moisture content) stress responses at the booting stage of wheat under controlled environmental conditions. HSI full range reflectance (280–2500 nm), CFI, and traditional responses (leaf water content, photosynthesis, and enzymatic activity) were measured from flag leaves. The potentiality of HSI to detect cellular damage in terms of enzymatic activity was explored by developing partial least square regression (PLSR) models, and spectral indices were calculated to characterize the responses to individual and combined stresses. Reflectance in 360, 700, 1400, 1900, and 2460 nm wavebands showed the most important variables in developing PLSR models for enzymes. Superoxide dismutase, peroxidase, and ascorbate peroxidase showed the highest R2c (0.99, 0.95, and 0.98), R2v (0.94, 0.90, 0.93), and the ratio of prediction to deviation (4.04, 3.06, and 3.85). CFI decreased under individual frost and combined frost and drought stresses. Ratio vegetation stress index (RVSI), green difference vegetation index (GDVI), difference vegetation index (DVI), and normalized difference water index (NDWI) were the most important variables and could be used to detect combined frost and drought by determining enzymatic activity and reactive oxygen species (ROS), verified by PLSR models. Spectral indices and enzyme activities showed a strong correlation in determining yield losses. Hence, HSI and CFI techniques successfully detected combined frost and drought stresses for rapid quantification.

Effect of Chloride Salinization on Barley Seedlings

The influence of moderate and strong chloride salinity on seedlings of barley (Hordeum vulgare L.) Nur variety was studied under controlled environment conditions. Exposure of seedlings to both moderate (100 mM) and high concentrations (200 mM) of NaCl for 7 days led to a slowdown in the growth of their roots and shoots. At the same time, in the variant using NaCl in moderate concentration, an increase in the content of pigments was noted in the leaves of seedlings (chlorophylls and carotenoids by 25 and 22%, respectively). Also the photosynthesis rate decreased by 25% (relative to the control). In contrast, under the influence of a high concentration of NaCl, the content of pigments, as well as stomatal conductance, decreased markedly, which was accompanied by an almost twofold slowdown in the rate of photosynthesis. At the same time, transpiration was inhibited and tissue hydration decreased. It was concluded that the resistance of barley to NaCl can be judged already in the early phases of plant development. It is also noted that the most sensitive to the presence of NaCl in the root environment are easily recorded morpho-physiological indicators – the linear size of the shoot and its raw biomass.

Humulus lupulus L. Strobilus Photosynthetic Capacity and Carbon Assimilation.

The economic value of Humulus lupulus L. (hop) is recognized, but the primary metabolism of the hop strobilus has not been quantified in response to elevated CO2. The photosynthetic contribution of hop strobili to reproductive effort may be important for growth and crop yield. This component could be useful in hop breeding for enhanced performance in response to environmental signals. The objective of this study was to assess strobilus gas exchange, specifically the response to CO2 and light. Hop strobili were measured under controlled environment conditions to assess the organ's contribution to carbon assimilation and lupulin gland filling during the maturation phase. Leaf defoliation and bract photosynthetic inhibition were deployed to investigate the glandular trichome lupulin carbon source. Strobilus-level physiological response parameters were extrapolated to estimate strobilus-specific carbon budgets under current and future atmospheric CO2 conditions. Under ambient atmospheric CO2, the strobilus carbon balance was 92% autonomous. Estimated strobilus carbon uptake increased by 21% from 415 to 600 µmol mol-1 CO2, 14% from 600 to 900 µmol mol-1, and another 8%, 4%, and 3% from 900 to 1200, 1500, and 1800 µmol mol-1, respectively. We show that photosynthetically active bracts are a major source of carbon assimilation and that leaf defoliation had no effect on lupulin production or strobilus photosynthesis, whereas individual bract photosynthesis was linked to lupulin production. In conclusion, hop strobili can self-generate enough carbon assimilation under elevated CO2 conditions to function autonomously, and strobilus bracts are the primary carbon source for lupulin biosynthesis.

Pyrolytic conversion of human hair to fuel: performance evaluation and kinetic modelling.

There are several environmental and human health impacts if human hair waste is not adequately disposed of. In this study, pyrolysis of discarded human hair was carried out. This research focused on the pyrolysis of discarded human hair under controlled environmental conditions. The effects of the mass of discarded human hair and temperature on bio-oil yield were studied. The proximate and ultimate analyses and calorific values of disposed of human hair, bio-oil, and biochar were determined. Further, chemical compounds of bio-oil were analyzed using a gas chromatograph and a mass spectrometer. Finally, the kinetic modeling and behavior of the pyrolysis process were characterized through FT-IR spectroscopy and thermal analysis. Based on the optimized mass of disposed of human hair, 250g had a better bio-oil yield of 97% in the temperature range of 210-300°C. The different parameters of bio-oil were: pH (2.87), specific gravity (1.17), moisture content (19%), heating value (19.34MJ/kg), and viscosity (50 CP). C (56.4%), H (6.1%), N (0.16%), S (0.01%), O (38.4%), and Ash (0.1%) were discovered to be the elemental chemical composition of bio-oil (on a dry basis). During breakdown, the release of different compounds like hydrocarbons, aldehydes, ketones, acids, and alcohols takes place. According to the GC-MS results, several amino acids were discovered in the bio-oil, 12 abundant in the discarded human hair. The FTIR and thermal analysis found different concluding temperatures and wave numbers for functional groups. Two main stages are partially separated at about 305°C, with maximum degradation rates at about 293oC and 400-4140°C, respectively. The mass loss was 30% at 293 0C and 82% at temperatures above 293 0C. When the temperature reached 4100C, the entire bio-oil from discarded human hair was distilled or thermally decomposed.

Test Method for Studying the Shrinkage Effect under Controlled Environmental Conditions for Concrete Reinforced with Coconut Fibres.

This study proposes a novel test method and corresponding procedure to evaluate how coconut fibres affect crack propagation rates resulting from plastic shrinkage during the accelerated drying of concrete slabs. The experiment employed concrete plate specimens, which were used to simulate slab structural elements with a surface dimension notably greater than their thickness. These slabs were reinforced with coconut fibre with 0.5%, 0.75%, and 1% fibre content. A wind tunnel was designed to simulate two significant climate parameters (wind speed and air temperature), which could impact the cracking behaviour of surface elements. The proposed wind tunnel allowed air temperature to be controlled alongside wind speed while monitoring moisture loss and the cracking propagation process. During testing, a photographic recording method was used to evaluate cracking behaviour, with the total crack length serving as a parameter to assess the impact of fibre content on the crack propagation of slab surfaces. Additionally, crack depth was measured using ultrasound equipment. The results indicate that the proposed test method was appropriate for future research, allowing for the evaluation of the effect of natural fibres on the plastic shrinkage behaviour of surface elements under controlled environmental conditions. Based on initial studies and the results obtained through the proposed test method, concrete containing 0.75% fibre content exhibited significantly reduced crack propagation on slab surfaces, as well as a reduction in the crack depth caused by plastic shrinkage during the early age of the concrete.

Growth and Quality of Leaf and Romaine Lettuce Grown on a Vertical Farm in an Aquaponics System: Results of Farm Research

The integration of indoor vertical cultivation with a recirculating aquaculture system into an aquaponic system has the potential to become one of the most effective sustainable production systems for fish and leafy vegetables. In this study, lettuce was produced on rafts in a coupled recirculation aquaponic system in the plant factory under controlled environmental conditions. The aims of this study were to evaluate the yield, mineral status, and health-promoting bioactive compounds of leaf and romaine lettuce cultivars grown in a recirculating aquaponic system. The yield and biometric parameters and quality parameters of lettuce leaves (nitrate, mineral, L-ascorbic acid, carotenoid, phenolic compound, and total polyphenolic contents) were examined. Monitoring of the water in the aquaponic system showed a low concentration of nitrates, phosphorus (P), potassium (K), and magnesium (Mg), but the proportion of mineral nutrients as well as pH were stable throughout the lettuce cultivation period. The heads of romaine lettuce ‘Yakina’, ‘Pivotal’, and ‘Waygo’ reached a fresh weight of 86 g, on average, 23% higher than the leaf lettuce ‘Nordice’ over a three-week cultivation period. Despite the low nutrient concentration in the aquaponic solution, the nutrient status of the romaine lettuces ‘Yakina’ and ‘Pivotal’ was within the optimal range. The concentrations of chlorophyll a and carotenoids in ‘Yakina’ and ‘Pivotal’ were higher than those in ‘Nordice’ and ‘Waygo’. The nitrate, phosphorus, and potassium contents in the leaves of ‘Nordice’ and ‘Waygo’ were below the optimal range; however, their polyphenol concentrations were the highest. Our results indicate that the effectiveness of aquaponic cultivation of lettuce in terms of biomass production and the nutritional and health-promoting value of lettuce depends on the plant genotype.

Gene B5 in Cotton Confers High and Broad Resistance to Bacterial Blight and Conditions High Amounts of Sesquiterpenoid Phytoalexins.

Bacterial blight resistance gene B5 has received little attention since it was first described in 1950. A near-isogenic line (NIL) of Gossypium hirsutum cotton, AcB5, was generated in an otherwise bacterial-blight-susceptible 'Acala 44' background. The introgressed locus B5 in AcB5 conferred strong and broad-spectrum resistance to bacterial blight. Segregation patterns of test crosses under Oklahoma field conditions indicated that AcB5 is likely homozygous for resistance at two loci with partial dominance gene action. In controlled-environment conditions, two of the four copies of B5 were required for effective resistance. Contrary to expectations of gene-for-gene theory, AcB5 conferred high resistance toward isogenic strains of Xanthomonas citri subsp. malvacearum carrying cloned avirulence genes avrB4, avrb7, avrBIn, avrB101, and avrB102, respectively, and weaker resistance toward the strain carrying cloned avrb6. The hypothesis that each B gene, in the absence of a polygenic complex, triggers sesquiterpenoid phytoalexin production was tested by measurement of cadalene and lacinilene phytoalexins during resistant responses in five NILs carrying different B genes, four other lines carrying multiple resistance genes, as well as susceptible Ac44E. Phytoalexin production was an obvious, but variable, response in all nine resistant lines. AcB5 accumulated an order of magnitude more of all four phytoalexins than any of the other resistant NILs. Its total levels were comparable to those detected in OK1.2, a highly resistant line that possesses several B genes in a polygenic background.

Optimal root oxygen release from two macrophytes Saururus cernuus L. and Pistia stratiotes L. varies with light and temperature in simulated constructed wetlands microcosms

Different environmental factors influence photosynthesis, transpiration, stomatal conductance, and oxygen released from macrophytes' roots. We measured several physiological parameters of Saururus cernuus L. (Lizard's Tail) and Pistia stratiotes L. (Water Cabbage) by exposing the plants to various controlled environmental conditions. The oxygen released from the plant roots was also used to treat the chemical and biological oxygen demand in wastewater in microcosms. This work determined that photosynthetic rate and oxygen release were dependent not only on the plant species but also on the light intensity exposed. The highest rate of photosynthesis differed considerably between the two plants, as S. cernuus required more light intensity than P. stratiotes. Maximum root oxygen release was at peak photosynthesis, thus correlated with light intensity. The temperature had an effect on stomatal conductance, photosynthesis rate, and transpiration rate was affected by the wind speed. For the highest stomatal conductance and photosynthesis, P. stratiotes required a higher temperature than S. cernuus. Stomatal conductance also influenced the oxygen released from plant roots. Furthermore, a relationship was determined between physiological processes and their potential to release oxygen from the roots where the reduction in COD and BOD measured at the end of the experiment was largely attributed to the oxygen that the macrophytes added to the substrate through their roots. The results of this study provide a good benchmark for plant scientists to predict the physiological processes of plants in response to different environmental conditions to control the negative impacts of harsh environmental conditions on plants' ability to release oxygen in their rhizosphere and to improve the efficiency of CW.

CH4 transport in wetland plants under controlled environmental conditions – untangling the impacts of phenology versus other factors

CH4 transport in wetland plants under controlled environmental conditions – untangling the impacts of phenology versus other factors

An Alternative Method to Evaluate Resistance to Pear Scab (Venturia nashicola).

Two pear cultivars with different degrees of resistance to Venturia nashicola were evaluated on the basis of a disease severity rating for pear scab resistance under controlled environmental condition. Two inoculation techniques were tested: the procedure for inoculation by dropping conidia suspension of V. nashicola; the procedure by deposition of agar plug on the abaxial surface of pear leaves. All tested cultivars resulted in blight symptoms on the inoculated leaves and became spread to uninoculated region or other leaves. Although both methods provide satisfactory infection of V. nashicola on pear leaves, the mycelial plug method of inoculation was more reliable than the spray inoculation method for the evaluation of pear scab disease resistance. The incubation period of V. nashicola in the resistant pear cultivar, Greensis was longer than that in the susceptible cultivar, Hwasan.

Production of, Factors Affecting, Gene Regulations, and Challenges in Tissue Cultured Plant through Soilless Culture.

Soilless culture also known as water based culture and substrate based culture has immense potential to grow tissue cultured plants in a closed and controlled environment system. This review analyzes the various factors that affect the vegetative growth, reproductive growth, metabolic processes, and gene regulatory functions of tissue cultured plants and the suitability of soilless culture for tissue culture plants. Experiments show that morphological and reproductive abnormalities are mitigated in tissue cultured plants by gene regulation in a closed and controlled environment system. Various factors of a soilless culture influence gene regulation and enhance cellular, molecular, and biochemical processes and compensate constraints in tissue cultured plants in closed and controlled environment conditions. The soilless culture can be utilized to harden and grow tissue culture plants. The tissue cultured plants counter water logging problems and are supplied with nutrients at 7 day intervals in the water based culture. It is necessary to analyze the involvement of regulatory genes in detail in combating challenges of tissue cultured plants in soilless cultures under closed systems. Detailed studies are also required to determine anatomy, genesis, and function of microtuber cells in tissue cultured plants.

Stability and suitability of genotypes and environment to Ascochyta blight of chickpea.

Ascochyta blight (AB) is a major biotic constraint to chickpea production internationally. The disease caused by the phytopathogenic fungus Ascochyta rabiei is highly favored by prolonged spells of low temperature and high humidity. The disease scenario is expected to aggravate in the near future as a result of rapidly changing climatic conditions and the emergence of fungicide-resistant pathogen strains. Tapping into host-plant resistance is the most logical way to preempt such a crisis. Presently, high levels of stable resistance against AB are yet to be identified from the chickpea gene pool. The present study was aimed at facilitating this process through multi-environment testing of chickpea genotypes. Using the GGE biplot analysis method, we could identify three genotypes, viz., ICCV 16508, ICCV 16513, and ICCV 16516, from the International Ascochyta Blight Nursery, which showed consistent moderate resistance reactions across all the tested environments. Moreover, we were able to evaluate the test locations for their suitability to support AB screening trials. Ludhiana and Palampur locations were identified as the most ideal for continual screening in the future. Controlled environment screening at the ICRISAT location offered to reduce large plant populations to small meaningful sizes through initial screening under controlled environment conditions. This study will further improve the scope of phenotyping and sources of stable resistance to be utilized in future AB resistance breeding programs.

Definition of a thermal comfort rating scale for mountaneering boots

This study investigates the thermal insulation and moisture management of three types of mountaneering boots and simulated hiking activities under controlled environmental conditions with two elite athletes. Temperature and humidity were determined with six wireless probes placed on the most exposed parts of the foot (hallux, middle toe, little toe, dorsum, ankle and sole). Thermal images were taken to record the thermal insulation of each sample. Methodologically, the study aims to simulate every movement and activity of alpinism in order to realistically evaluate the conditions of use of this kind of footwear (also taking into account the lacing pressure exerted on the foot). Based on the results obtained, in a further step it will be possible to define the best solution in terms of combination of materials by creating a comfort scale for hiking boots.

Tissue Culture—A Sustainable Approach to Explore Plant Stresses

Plants are constantly faced with biotic or abiotic stress, which affects their growth and development. Yield reduction due to biotic and abiotic stresses on economically important crop species causes substantial economic loss at a global level. Breeding for stress tolerance to create elite and superior genotypes has been a common practice for many decades, and plant tissue culture can be an efficient and cost-effective method. Tissue culture is a valuable tool to develop stress tolerance, screen stress tolerance, and elucidate physiological and biochemical changes during stress. In vitro selection carried out under controlled environment conditions in confined spaces is highly effective and cheaper to maintain. This review emphasizes the relevance of plant tissue culture for screening major abiotic stresses, drought, and salinity, and the development of disease resistance. Further emphasis is given to screening metal hyperaccumulators and transgenic technological applications for stress tolerance.

Three-dimensional printability of bismuth alloys with low melting temperatures

Equipment that can produce high thermal energy and provide controlled environmental conditions is required to use metals in three-dimensional (3D) printing technology. As a result, the costs of this equipment are relatively high. However, the potential for using simpler equipment for the 3D printing of alloys with low melting temperatures is remarkable. In this study, the printability of parts from low melting temperature alloys with a 3D printer using the fused deposition modeling (FDM) technique was investigated. Alloys with chemical compositions of Bi50Pb26.7Sn13.3CD10 and Bi50Pb25Sn25 were fabricated by FDM. The physical and mechanical properties of samples fabricated by FDM and conventional casting were then investigated. According to the data obtained, samples produced using FDM have lower tensile strength compared to traditional casting but show a greater elongation.

Symptom Assessment of Patients with Allergic Rhinitis Using an Allergen Exposure Chamber

Allergen exposure chambers (AECs) are clinical facilities that allow the exposure of participants to allergenic and non-allergenic airborne particles. They provide stable particle concentrations under controlled environmental conditions. This is of great importance both for diagnostic purposes and for the monitoring of treatment effects. Here, a protocol and the technical prerequisites for performing a safe and effective allergen challenge in subjects sensitized to airborne allergens (i.e., house dust mite [HDM]) in the ALL-MED AEC are presented. With this method, triggering allergic symptoms corresponds to natural exposure. This can be used for an allergy diagnosis or as a plausible endpoint in clinical trials, particularly for allergen immunotherapy (AIT). A controlled environment (temperature, humidity, and carbon dioxide [CO2]) in the chamber must be maintained. Allergen particles must be dispersed evenly within the AEC at stable levels throughout the challenge. For this presentation, allergic rhinitis (AR) patients sensitive to HDM allergens were enrolled. AR symptoms were assessed by the following parameters: total nasal symptom score (TNSS), acoustic rhinometry (ARM), peak nasal inspiratory flow (PNIF), and nasal secretion weight. The safety of the procedure was assessed by the peak expiratory flow rate (PEFR) and the forced expiratory volume in the first second (FEV1). The allergic subjects developed symptoms within 120 min of the trial. On average, the most intense symptoms appeared after 60-90 min and, after reaching a plateau, remained stable until the end of the trial.

Fusarium grosmichelii causes wilt disease on Tibouchina seecandra in China

Tibouchina seecandra is an evergreen shrub, a popular ornamental plant in China. From 2020 to 2021, a wilt disease was observed in T. seecandra in Guangdong province, China. The diseased plants showed typical wilt symptoms including drying out of lower leaves, plant dieback, and total death of the plant. When the diseased stems were sectioned, discolouration of vascular bundles was observed. At the commercial nurseries, the natural disease incidence reached almost 50%, leading to severe economic losses. The putative pathogen was isolated from symptomatic T. seecandra stems. Fusarium grosmichelii was identified as the causal agent by using morphology and molecular phylogeny of multi-loci (DNA-directed RNA polymerase II subunit, translation elongation factor1-alpha, and beta-tubulin) sequence data. Artificial inoculation assays were conducted on potted T. seecandra seedlings under controlled environmental conditions. The results showed that the fungus could produce wilt symptoms in T. seecandra which is similar to those observed in the field. The putative pathogen was re-isolated and Koch's postulates were fulfilled. This study provides the first report of F. grosmichelii causing T. seecandra wilt disease worldwide. Furthermore, these results will contribute to the knowledge of pathogenic Fusarium species on ornamental plants.

Selection for Sustainable Preservation through In Vitro Propagation of Mature Pyrus spinosa Genotypes Rich in Total Phenolics and Antioxidants

Pyrus spinosa Forssk. (almond-leaved pear) is a wild-growing native tree of the hilly countryside of Greece, which has recently gained interest for its valuable endogenous substances. In the present work, the determination of the total phenol content (TPC) and antioxidant capacity (AC) was carried out during 2021 and 2022 in leaves from 32 genotypes of mature wild-growing trees at four different locations of Central Macedonia District, Greece: Agia Anastasia, Chalkidiki, Lagadas and Pieria. The measurements taken from the leaf samples of all genotypes revealed a strong positive linear correlation between TPC and AC (R2 = 0.772). Two genotypes from Agia Anastasia, coded as AA2 and AA3, were comparatively the richest in TPC (44.86 for AA2 and 46.32 mg GAE/g fresh weight for AA3) and AC (70.31 and 71.21 μg AAE/g fresh weight for the same genotypes). For these two genotypes of high TPC and AC, an efficient micropropagation protocol was developed to preserve and multiply this valuable germplasm. Newly emerged shoot tips were excised from winter shoots and, after disinfestation, they were established on a modified Murashige and Skoog (MS) nutrient medium with 5 μΜ of 6-Benzyloaminopurine (BAP). For shoot multiplication, explants from clean cultures were transferred to Pear Medium 1 with 5 μΜ of BAP. The effect of the nutrient medium was tested by using five different nutrient media (modified MS, Pear Medium 1, Pear Medium 2, DKW and WPM) supplemented with 5 μΜ of BAP. Pear Medium 1 was the most effective in shoot formation. Among the four different BAP concentrations (0, 5, 10 and 20 μΜ) used in Pear Medium 1, 5 μΜ of BAP resulted in the production of the significantly highest number of shoots (22.7 shoots per explant, 2.4 cm long). The exposure of cultures to 10 μmol·m−2·s−1 for one week under light irradiance followed by 35 μmol·m−2·s−1 for four weeks increased both the number and length of the shoots produced. A 20-s dip of the shoot bases into 49.0 μΜ of Indole-3-butyric acid (IBA) in EtOH equally affected rooting in a modified rooting MS (79%) and Pear Medium 1 (80%). The root system developed better in the modified rooting MS medium (mean number of roots of 2.7 with a length of 3.9 cm). The acclimatization of the plantlets was successfully carried out (high survival rates five weeks after their establishment) on a perlite substrate under controlled environmental conditions.

Cross‐disciplinary insights into the mechanisms of plant cold hardiness: From molecules to ecosystems

Cross‐disciplinary insights into the mechanisms of plant cold hardiness: From molecules to ecosystems