Effect of some feed filament parameters and weave on compressional properties of air-jet textured yarn fabrics

9-13The influence of some feed filament parameters and weave on compression and recovery behaviour of air-jet textured yarn fabrics has been studied and compared with their corresponding parent yarn fabrics. Fabric low load compression-recovery behaviour has been analysed by defining initial thickness, compression parameter, recovery parameter and resiliency. Fabrics made from coarser yarn (larger total yarn dtex) have higher initial thickness and compression parameter while lower recovery parameter and resiliency, as compared to fabrics made from finer yarn. Fabrics are woven with two woven structures, namely plain and twill weave to assess the effect of fabric structure on compression and recovery behaviour of the fabrics. Twill woven fabrics exhibit a higher value of all compressional parameters compared to their equivalent plain woven fabrics. Parent yarn fabrics exhibit a low value of all compressional properties, irrespective of change in any feed yarn characteristics as compared to their equivalent textured yarn fabrics

Effect of some feed filament parameters and weave on compressional properties of air-jet textured yarn fabrics

The influence of some feed filament parameters and weave on compression and recovery behaviour of air-jet textured yarn fabrics has been studied and compared with their corresponding parent yarn fabrics. Fabric low load compression-recovery behaviour has been analysed by defining initial thickness, compression parameter, recovery parameter and resiliency. Fabrics made from coarser yarn (larger total yarn dtex) have higher initial thickness and compression parameter while lower recovery parameter and resiliency, as compared to fabrics made from finer yarn. Fabrics are woven with two woven structures, namely plain and twill weave to assess the effect of fabric structure on compression and recovery behaviour of the fabrics. Twill woven fabrics exhibit a higher value of all compressional parameters compared to their equivalent plain woven fabrics. Parent yarn fabrics exhibit a low value of all compressional properties, irrespective of change in any feed yarn characteristics as compared to their equivalent textured yarn fabrics

Effect of linear density of feed yarn filaments and air-jet texturing process variables on compressional properties of woven fabrics

The influence of yarn feed and process parameters used in the production of air-jet textured yarn on compression and recovery behavior of air-jet textured yarn fabric has been studied. Yarn linear density per filament and air-jet texturing process parameters, such as overfeed, air pressure and texturing speed are the key factors which influence yarn structure and hence fabric properties. The individual effect of feed yarn properties and air-jet process variables in the production of air-jet textured yarn has been studied in term of potential contribution and normalized regression coefficient on fabric low load compression behavior. Fabric low load compression-recovery behavior has been analyzed by defining compression parameter, recovery parameter and resiliency. Analysis shows that most dominating factor to explain the air-jet textured yarn fabric low-load compression properties is overfeed percentage, while linear density per filament is most dominating factor affecting fabric resiliency

Effect of linear density of feed yarn filaments and air-jet texturing process variables on compressional properties of fabrics

Effect of filament fineness and process parameters employed in the production of air-jet textured yarns has been studied on the compression and recovery of union fabrics made from air-jet textured yarns as weft and twisted filament yarns as warp. Filament linear density and process parameters such as overfeed, air pressure and texturing speed affect the textured yarn structure and hence fabric properties. The individual effect of filament fineness and process variables in the production of air-jet textured yarn has been studied in terms of potential contribution and normalized regression coefficient on fabric low load compression behavior. Fabric low load compression-recovery behavior has been analyzed in terms of compression parameter, recovery parameter and resiliency. Analysis shows that most dominating factor to explain the low load compression properties of air-jet textured yarn fabric is overfeed percentage, while linear density per filament is most dominating factor affecting fabric resiliency

A comparison of hydroponic and soil-based screening methods to identify salt tolerance in the field in barley

Success in breeding crops for yield and other quantitative traits depends on the use of methods to evaluate genotypes accurately under field conditions. Although many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. In this study, the salt tolerance, ion concentrations, and accumulation of compatible solutes of genotypes of barley with a range of putative salt tolerance were investigated using three growing conditions (hydroponics, soil in pots, and natural saline field). Initially, 60 genotypes of barley were screened for their salt tolerance and uptake of Na+, Cl–, and K+ at 150 mM NaCl and, based on this, a subset of 15 genotypes was selected for testing in pots and in the field. Expression of salt tolerance in saline solution culture was not a reliable indicator of the differences in salt tolerance between barley plants that were evident in saline soil-based comparisons. Significant correlations were observed in the rankings of genotypes on the basis of their grain yield production at a moderately saline field site and their relative shoot growth in pots at ECe 7.2 [Spearman’s rank correlation (rs)=0.79] and ECe 15.3 (rs=0.82) and the crucial parameter of leaf Na+ (rs=0.72) and Cl– (rs=0.82) concentrations at ECe 7.2 dS m−1. This work has established screening procedures that correlated well with grain yield at sites with moderate levels of soil salinity. This study also showed that both salt exclusion and osmotic tolerance are involved in salt tolerance and that the relative importance of these traits may differ with the severity of the salt stress. In soil, ion exclusion tended to be more important at low to moderate levels of stress but osmotic stress became more important at higher stress levels. Salt exclusion coupled with a synthesis of organic solutes were shown to be important components of salt tolerance in the tolerant genotypes and further field tests of these plants under stress conditions will help to verify their potential utility in crop-improvement programmes

Peat swamp forest conservation withstands pervasive land conversion to oil palm plantation in North Selangor, Malaysia

Tropical deforestation remains one of the major global challenges of the twenty-first century driven to a large extent by the conversion of land for agricultural purposes, such as palm oil production. Malaysia is one of the world’s largest palm oil producers and has seen widespread conversion to oil palm from primary forest, including peat swamp forest (PSF). This study investigates the rate and extent of pervasive oil palm expansion in and around North Selangor Peat Swamp Forest (NSPSF) over the last three decades, exploring how land conversion has affected the region’s tropical forests, and assessing the relative success of PSF conservation measures. Time-series Landsat imagery was used to assess thematic land cover change and improvement in vegetation condition since NSPSF was given protected status in 1990. The results show a near tripling in oil palm cover throughout North Selangor, from 24,930 ha in 1989 to 70,070 ha in 2016; while at the same time tropical forest cover shrank from 145,570 ha to 88,400 ha. Despite concerns over the sustainability and environmental impact of such rapid oil palm conversion at a regional level, at the local scale, NSPSF represents a relative conservation success story. Effective land stewardship by government and non-governmental organization (NGO) management actors has limited illegal encroachment of oil palm around the reserve boundary. PSF rehabilitation measures have also markedly improved vegetation condition in NSPFS’s interior. These findings have broad significance for how oil palm agriculture is managed and especially for PSF stewardship and conservation, and the approaches described here may be usefully adopted elsewhere in Southeast Asia and around the world

Additive effects of Na+ and Cl– ions on barley growth under salinity stress

Soil salinity affects large areas of the world’s cultivated land, causing significant reductions in crop yield. Despite the fact that most plants accumulate both sodium (Na+) and chloride (Cl–) ions in high concentrations in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na+ accumulation. It has previously been suggested that Cl– toxicity may also be an important cause of growth reduction in barley plants. Here, the extent to which specific ion toxicities of Na+ and Cl– reduce the growth of barley grown in saline soils is shown under varying salinity treatments using four barley genotypes differing in their salt tolerance in solution and soil-based systems. High Na+, Cl–, and NaCl separately reduced the growth of barley, however, the reductions in growth and photosynthesis were greatest under NaCl stress and were mainly additive of the effects of Na+ and Cl– stress. The results demonstrated that Na+ and Cl– exclusion among barley genotypes are independent mechanisms and different genotypes expressed different combinations of the two mechanisms. High concentrations of Na+ reduced K+ and Ca2+ uptake and reduced photosynthesis mainly by reducing stomatal conductance. By comparison, high Cl– concentration reduced photosynthetic capacity due to non-stomatal effects: there was chlorophyll degradation, and a reduction in the actual quantum yield of PSII electron transport which was associated with both photochemical quenching and the efficiency of excitation energy capture. The results also showed that there are fundamental differences in salinity responses between soil and solution culture, and that the importance of the different mechanisms of salt damage varies according to the system under which the plants were grown

Persistent neuropsychiatric symptoms after COVID-19: a systematic review and meta-analysis.

The nature and extent of persistent neuropsychiatric symptoms after COVID-19 are not established. To help inform mental health service planning in the pandemic recovery phase, we systematically determined the prevalence of neuropsychiatric symptoms in survivors of COVID-19. For this pre-registered systematic review and meta-analysis (PROSPERO ID CRD42021239750), we searched MEDLINE, EMBASE, CINAHL and PsycINFO to 20 February 2021, plus our own curated database. We included peer-reviewed studies reporting neuropsychiatric symptoms at post-acute or later time-points after COVID-19 infection and in control groups where available. For each study, a minimum of two authors extracted summary data. For each symptom, we calculated a pooled prevalence using generalized linear mixed models. Heterogeneity was measured with I 2. Subgroup analyses were conducted for COVID-19 hospitalization, severity and duration of follow-up. From 2844 unique titles, we included 51 studies (n = 18 917 patients). The mean duration of follow-up after COVID-19 was 77 days (range 14-182 days). Study quality was most commonly moderate. The most prevalent neuropsychiatric symptom was sleep disturbance [pooled prevalence = 27.4% (95% confidence interval 21.4-34.4%)], followed by fatigue [24.4% (17.5-32.9%)], objective cognitive impairment [20.2% (10.3-35.7%)], anxiety [19.1% (13.3-26.8%)] and post-traumatic stress [15.7% (9.9-24.1%)]. Only two studies reported symptoms in control groups, both reporting higher frequencies in COVID-19 survivors versus controls. Between-study heterogeneity was high (I 2 = 79.6-98.6%). There was little or no evidence of differential symptom prevalence based on hospitalization status, severity or follow-up duration. Neuropsychiatric symptoms are common and persistent after recovery from COVID-19. The literature on longer-term consequences is still maturing but indicates a particularly high prevalence of insomnia, fatigue, cognitive impairment and anxiety disorders in the first 6 months after infection

Soil and aquifer salinization: toward an integrated approach for salinity management of groundwater

Degradation of the quality of groundwater due to salinization processes is one of the key issues limiting the global dependence on groundwater in aquifers. As the salinization of shallow aquifers is closely related to root-zone salinization, the two must be considered together. This chapter initially describes the physical and chemical processes causing salinization of the root-zone and shallow aquifers, highlighting the dynamics of these processes and how they can be influenced by irrigation and drainage practices, thus illustrating the connectivity between soil and groundwater salinization. The processes leading to aquifer salinization in both inland and coastal areas are discussed. The roles of extractive resource industries, such as mining and coal bed methane operations, in causing aquifer salinization are also outlined. Hydrogeochemical changes occurring during salinization of aquifers are examined with the aid of Piper and Mixing Diagrams. The chapter then illustrates the extent of the problem of groundwater salinization as influenced by management and policy using two case studies. The first is representative of a developing country and explores management of salt-affected soils in the Indus Valley, Pakistan, while the second looks at a developed country, and illustrates how through monitoring we can deducecauses of shallow aquifer salinity in the Namoi Catchment of NSW, Australia. Finally, there is a section on integration and conclusions where we illustrate how management to mitigate salinization needs to be integrated with policy to diminish the threat to productivity that occurs with groundwater degradation

High concentrations of Na+ and Cl– ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress

Despite the fact that most plants accumulate both sodium (Na+) and chloride (Cl–) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na+ accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na+ and to Cl– separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na+ and Cl– to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na+ and Cl–. Soils were prepared which were treated with Na+ or Cl– by using a combination of different Na+ salts and Cl– salts, respectively, or with NaCl. While this method produced Na+-dominant and Cl–-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na+ and high Cl– reduced growth of faba bean but plants were more sensitive to Cl– than to Na+. The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl– more than the concentration of Na+. The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na+ and Cl– simultaneously, but the effects of the two ions may differ. High Cl– concentration reduces the photosynthetic capacity and quantum yield due to chlorophyll degradation which may result from a structural impact of high Cl– concentration on PSII. High Na+ interferes with K+ and Ca2+ nutrition and disturbs efficient stomatal regulation which results in a depression of photosynthesis and growth. These results suggest that the importance of Cl– toxicity as a cause of reductions in growth and yield under salinity stress may have been underestimated