521 research outputs found
The Cloze Procedure and Informal Reading Inventory: A Correlative Study
This study compared the cloze procedure and informal reading inventory at reading levels ranging from third through seventh grade. Twenty-four elementary students, judged by their teachers as not having reading difficulties, were selected from fourth, fifth, and sixth grade classes and. administered the two test instruments. The correlations, at each reading level were not significant at the .01 level as determined by the Pearson Product-Moment formula. Recommendations included the use of more subjects and suggestions for additional research
Who You Gonna Call?: Creating a Call List for Your Facility\u27s Disaster Plan
Preservation can involve responding to active and pressing matters. But not all buildings are lost to the bulldozer. Many are lost to natural and human disasters like storms and water. A Disaster Plan is a common document used by museums and history organizations. Learn how to develop a contact list for a Disaster Response Plan so you know whom to call when disaster strikes
Root architecture and productivity of three grass species under salt stress
Salinity not only directly affects above-ground plant growth and development but also root system architecture and functioning. The mature root system of grasses is composed of primary and seminal roots with their laterals and crown roots. The root structure strongly influences the plant's ability to take up water and nutrients, thereby affecting plant health and tolerance to abiotic stress. Three grass species, Lolium perenne, Festuca rubra and Puccinellia maritima from habitats with different salinities, were screened for salt-induced changes in root architecture. Scans of roots were used to quantify root's structural and architectural traits using the RootNav software package. The results show that: 1) salinity affects root system architecture differently in the three grass species studied: in Festuca rubra and Puccinellia maritima salinity promoted primary root growth; 2) seminal root length of Lolium perenne and Puccinellia maritima was stimulated significantly by salinity, whereas in F. rubra no stimulation occurred up to 150 mM NaCl and seminal root length was inhibited at 200 mM; And 3) salinity inhibited lateral root growth in L. perenne, but promoted lateral root growth in both F. rubra and P. maritima
Tolerance to environmental stresses:Do fungal endophytes mediate plasticity in <i>Solanum dulcamara</i>?
Salinity imposes constraints on plant growth and development. Efforts have been made to develop salt-tolerant crops by different methods, the outcomes have not yet been sufficiently satisfactory. Plants depend on their symbiotic partners such as fungal symbionts to cope with stress conditions such as salinity. Bittersweet nightshade (Solanum dulcamara) has a wide ecological amplitude. Although S. dulcamara is becoming a model plant species, its associated fungal symbionts have hardly been studied. Here we propose that its symbiotic, endophytic fungi may be responsible for S. dulcamara's wide ecological amplitude. We examined the composition of endophytic fungal communities in S. dulcamara from contrasting habitats, i.e., dry and wet regions. We developed a method to select potential isolates based on their ability to colonize, grow and impart tolerance under stress conditions. The isolates identified from this study could potentially be used to improve crop productivity under suboptimal conditions
Effect of culture conditions on the performance of lignocellulose-degrading synthetic microbial consortia
In this study, we examined a synthetic microbial consortium, composed of two selected bacteria, i.e., Citrobacter freundii so4 and Sphingobacterium multivorum w15, next to the fungus Coniochaeta sp. 2T2.1, with respect to their fate and roles in the degradation of wheat straw (WS). A special focus was placed on the effects of pH (7.2, 6.2, or 5.2), temperature (25 versus 28 °C), and shaking speed (60 versus 180 rpm). Coniochaeta sp. 2T2.1 consistently had a key role in the degradation process, with the two bacteria having additional roles. Whereas temperature exerted only minor effects on the degradation, pH and shaking speed were key determinants of both organismal growth and WS degradation levels. In detail, the three-partner degrader consortium showed significantly higher WS degradation values at pH 6.2 and 5.2 than at pH 7.2. Moreover, the two bacteria revealed up to tenfold enhanced final cell densities (ranging from log8.0 to log9.0 colony forming unit (CFU)/mL) in the presence of Coniochaeta sp. 2T2.1 than when growing alone or in a bacterial bi-culture, regardless of pH range or shaking speed. Conversely, at 180 rpm, fungal growth was clearly suppressed by the presence of the bacteria at pH 5.2 and pH 6.2, but not at pH 7.2. In contrast, at 60 rpm, the presence of the bacteria fostered fungal growth. In these latter cultures, oxygen levels were significantly lowered as compared to the maximal levels found at 180 rpm (about 5.67 mg/L, ~ 62% of saturation). Conspicuous effects on biomass appearance pointed to a fungal biofilm–modulating role of the bacteria
Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance
Developments in adaptation to salinity at the crop level
The domestication of halophytic species and their use in agriculture has been tested by several authors to replace or supplement the vegetation of saline rangelands. In adopting plants that were originally gathered in nature for controlled cultivation under farmers’ care, the selection favored plant species that were fast-growing, performed well in the absence of other competition and disturbed soil, did not have extensive defense traits, such as thorns or toxins, and produced many seeds. Most of the saline agriculture crops have only recently been entered into breeding and selection programs, although several studies have been done on what people can consider landraces, many of the traits associated with elite varieties have not been systematically studied yet
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