harsh environments
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Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 202
Author(s):  
María Laura Foschi ◽  
Mariano Juan ◽  
Bernardo Pascual ◽  
Nuria Pascual-Seva

The caper is a shrub that adapts to harsh environments when it is established, but it presents serious difficulties in its propagation, both by cuttings and by seeds. Its seeds have low germination percentages, and germination is a very slow process. Significant increases in germination have been obtained with scarification and with the addition of gibberellic acid (GA3) to the substrate, leading to the hypothesis that they have possible physical and physiological dormancy. However, the only way to examine the water-impermeability of the cover is through imbibition analysis. This study analyzes the imbibition, viability, and germination of two seed lots, obtained in different years and evaluated immediately after their collection (FS) and after being stored (7 °C) for one month (DS) and one year (SS). The seed moisture content stabilizes from the fourth day, exceeding in all cases 31% in all three seed states tested (FS, DS and SS). This allows the germination of all viable seeds, only with the addition of GA3 to the germination substrate, without the need for scarification, so that caper seeds exclusively appear to present a physiological latency. Germination decreased in storage, even with just one month. With the GA3 addition, high germination values were obtained (up to 95% in FS).


2022 ◽  
Author(s):  
Zhiqiang Shao ◽  
Yalin Wu ◽  
Shuang Wang ◽  
Yan Wang ◽  
Zhiqiang Sun ◽  
...  

2022 ◽  
Author(s):  
Allison E. Johnson ◽  
Joseph F. Welklin ◽  
Ian R. Hoppe ◽  
Daizaburo Shizuka

Cooperatively breeding species exhibit a range of social behaviors associated with different costs and benefits to group-living, often in association with different environmental conditions. For example, species in which collective-care of offspring reduces the cost of reproduction are more common in harsh environments (true cooperative breeding), while species that collectively defend resources are present in benign environments (family-living). Here, we examine whether environment also shapes sociality within cooperatively-breeding species. We illustrate that Purple-backed Fairywrens, which primarily gain intrinsic, or collective-care benefits, have larger groups in hot, dry environments and smaller groups in cool, wet environments, whereas Superb Fairywrens which primarily gain extrinsic, or resource defense benefits, exhibit the opposite trend. We suggest differences in the costs and benefits of sociality contribute to these opposing ecogeographic patterns, demonstrating that comparisons of intraspecific patterns of social variation across species can provide insight into how ecology shapes transitions between social systems.


2022 ◽  
Author(s):  
Joshua Hargis ◽  
William E. Swain ◽  
Daniel R. Guildenbecher ◽  
Sean P. Kearney ◽  
Daniel R. Richardson
Keyword(s):  

2022 ◽  
Author(s):  
Lihua Zhao ◽  
Tianhao Li ◽  
Bijie Wang ◽  
Ke Chen ◽  
Xiao Hu ◽  
...  

Poly(siloxane-carborane)s are a class of polymeric materials which can be used for harsh environments. Poly(cyclosiloxane-carborane)s were prepared through hydrosilylation of cyclosiloxane and vinyl modified carborane cage. The structure of as-prepared...


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 20
Author(s):  
Gamal A. El-Hiti ◽  
Dina S. Ahmed ◽  
Emad Yousif ◽  
Omar S. A. Al-Khazrajy ◽  
Mustafa Abdallh ◽  
...  

The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers. Recently, polyphosphates, Schiff bases, and organometallic complexes were synthesized and used as potential ultraviolet absorbers for polymeric materials. They reduced the damage caused by accelerated and natural ultraviolet aging, which was confirmed by inspecting the surface morphology of irradiated polymeric films. For example, atomic force microscopy revealed that the roughness factor of polymers’ irradiated surfaces was improved significantly in the presence of ultraviolet absorbers. In addition, the investigation of the surface of irradiated polymers using scanning electron microscopy showed a high degree of homogeneity and the appearance of pores that were different in size and shape. The current work surveys for the first time the use of newly synthesized, ultraviolet absorbers as additives to enhance the photostability of polymeric materials and, in particular, polyvinyl chloride and polystyrene, based mainly on our own recent work in the field.


2021 ◽  
Vol 14 (1) ◽  
pp. 195-206
Author(s):  
Z. Abdullahi ◽  
A.A. Abdulrahman

Samples of Jatropha curcas, a non-edible biodiesel plant, which tolerates harsh environments was collected from an industrial area with high anthropogenic activities (Challawa Industrial area, Kano, Nigeria)and sorted into leaves, stems and roots. The aim is to assess the potentials of Jatropha curcas in accumulation and translocation of six Potentially Toxic Elements (PTEs) (Zn, Cu, Cd, Cr, Pb and Ni) from the soil media. Atomic Absorption Spectroscopy (AAS) was used to assess the concentrations. The bioaccumulation/ transfer of metals from roots to shoots and from soil to roots were evaluated in terms of translocation (TF) and bioconcentration factor (BCF). TF values of 1.02, 4.92, 2.68, 3.73, 1.5 and 3.19 for Zn, Cu, Cd, Cr, Pb and Ni respectively indicate that J. curcas was efficient in translocation of PTEs from roots to shoots. This is an indication that the plant is therefore suitable for phytoextraction of Zn, Cu, Cd, Cr, Pb and Ni. But CF value of 0.66 and 0.70 for Cu and Pb on the other hand shows that J. curcas is less able to translocate these two metals (Cu and Pb) indicating ineffective transfer. This show that J. curcas may be suitable a candidate for phytostabilization of Copper and lead in contaminated soils in the study area.


GPS Solutions ◽  
2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Min Li ◽  
Tianhe Xu ◽  
Meiqian Guan ◽  
Fan Gao ◽  
Nan Jiang
Keyword(s):  

2021 ◽  
Vol 153 (A1) ◽  
Author(s):  
M Lamas ◽  
L Carral

This paper considers the structures used today in the maritime and ocean industries to accommodate people in semi- permanent accommodation at sea: the floating hotels, or flotels. They have mainly been developed to support the activities of the offshore oil & gas industry, although in coastal areas they are widely used for several purposes, mainly as commercial hotels, but with a quite different philosophy of use. The objective of the paper is to show how the term flotel is used to denominate very different craft that, while serving the same purpose (provide floating accommodation), have a totally different configuration according to the place where they are located: in protected waters in coastal areas (where the craft are sometimes called coastels), in benign and shallow waters of the open ocean or in the harsh environments of deep waters, etc.


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