scholarly journals Extrafloral nectary phenotypic plasticity is damage- and resource-dependent in Vicia faba

2006 ◽  
Vol 2 (4) ◽  
pp. 583-585 ◽  
Author(s):  
Edward B Mondor ◽  
Michelle N Tremblay ◽  
Russell H Messing
Keyword(s):  
Phenotypic Plasticity ◽  
Vicia Faba ◽  
General Pattern ◽  
Leaf Tissue ◽  
Leaf Damage ◽  
High Resource ◽  
Resource Limited ◽  
Npk Fertilizer ◽  
Resource Levels ◽  
Secretion Rates

Phenotypic plasticity enables many damaged plants to increase nectar secretion rates from extrafloral nectaries (EFNs), or in the case of broad bean, Vicia faba L., to produce additional EFNs, to attract natural enemies of herbivores. While plants benefit greatly from these defensive mutualisms, the costs of producing EFNs are largely unknown. We hypothesized that if EFN production is costly, then damaged plants with high resource levels would be able to produce more EFNs than plants that are resource-limited. Here, we show that this indirect inducible defence does follow this general pattern. Vicia faba enriched with 6 or 12 g of 14 : 14 : 14 NPK fertilizer increased EFN numbers after leaf damage by 46 and 60%, respectively, compared with nutrient-poor plants. Thus, EFN production is both damage- and resource-dependent. Analogous to direct defences, production of EFNs may limit the overall loss of leaf tissue when risk of herbivory increases.

scholarly journals Caring for Children With Life-Limiting Illness in Bloemfontein, South Africa: Challenging the Assumptions of the ‘Good Death’

2020 ◽  
pp. 003022282094409
Author(s):  
Callie Daniels-Howell
Keyword(s):  
Hospice Care ◽  
Meaning Making ◽  
Good Death ◽  
Resource Limited Settings ◽  
High Resource ◽  
Resource Limited ◽  
Resource Setting ◽  
Alternate Forms ◽  
Open Discussion ◽  
And Control

Theories of good death focused on acceptance, control, and meaning-making inform adult palliative care in high-resource settings. As children’s palliative and hospice care (CPHC) develops in resource-limited settings, critical conceptualisations of a good death for children across these diverse settings are unknown. Assessed against high-resource setting tenets of good death from carer perspectives, results suggest: carer agency is limited; advanced discussion of death does not occur; distress results from multiple burdens; basic survival is prioritised; physical pain is not an emphasised experience; and carers publicly accept death quickly while private grief continues. Hegemonic conceptions of ‘good death’ for children do not occur in contexts where agency is constrained and discussing death is taboo, limiting open discussion, acceptance, and control of dying experiences. Alternate forms of discourse and good death could still occur. Critical, grounded conceptualisations of good death in individual resource-limited settings should occur in advance of CPHC development to effectively relieve expansive suffering in these contexts.

scholarly journals Predation selects for smaller eye size in a vertebrate: effects of environmental conditions and sex

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182625 ◽  
Author(s):  
Richard Svanbäck ◽  
Frank Johansson
Keyword(s):  
Visual Acuity ◽  
Phenotypic Plasticity ◽  
Experimental Evidence ◽  
Predation Risk ◽  
Environmental Conditions ◽  
Retinal Image ◽  
The Other ◽  
Eye Size ◽  
Fish Predators ◽  
Resource Levels

Increased eye size in animals results in a larger retinal image and thus improves visual acuity. Thus, larger eyes should aid both in finding food as well as detecting predators. On the other hand, eyes are usually very conspicuous and several studies have suggested that eye size is associated with predation risk. However, experimental evidence is scant. In this study, we address how predation affects variation in eye size by performing two experiments using Eurasian perch juveniles as prey and either larger perch or pike as predators. First, we used large outdoor tanks to compare selection due to predators on relative eye size in open and artificial vegetated habitats. Second, we studied the effects of both predation risk and resource levels on phenotypic plasticity in relative eye size in indoor aquaria experiments. In the first experiment, we found that habitat altered selection due to predators, since predators selected for smaller eye size in a non-vegetated habitat, but not in a vegetated habitat. In the plasticity experiment, we found that fish predators induced smaller eye size in males, but not in females, while resource levels had no effect on eye size plasticity. Our experiments provide evidence that predation risk could be one of the driving factors behind variation in eye size within species.

Trauma

2020 ◽  
pp. 197-228
Author(s):  
Sarah Hodges ◽  
Sanja Janjanin ◽  
Judith Kendell ◽  
Nur Lubis ◽  
David Nott ◽  
...  
Keyword(s):  
Road Traffic ◽  
Damage Control ◽  
Head Injuries ◽  
Damage Control Surgery ◽  
Armed Conflicts ◽  
Difficult Patient ◽  
Middle Income ◽  
Middle Income Countries ◽  
High Resource ◽  
Resource Limited

In low- and middle-income countries, trauma, often from road traffic collisions, is one of the leading causes of morbidity and mortality. The approach to treating trauma in resource limited settings can be quite different to that in high-resource settings, requiring a lot of improvisation. The concepts of damage control surgery and resuscitation are covered, as are considerations for difficult patient groups such as head injuries, burns, and spinal injuries. The injury patterns seen as a result of armed conflicts (gun shots, blast injuries) will be unfamiliar to most anaesthetists and are also addressed in the chapter.

Screening eucalypts for frost tolerance in breeding programs

1992 ◽  
Vol 22 (9) ◽  
pp. 1271-1277 ◽  
Author(s):  
C.A. Raymond ◽  
J.V. Owen ◽  
K.G. Eldridge ◽  
C.E. Harwood
Keyword(s):  
Data Analysis ◽  
Genetic Selection ◽  
Leaf Tissue ◽  
Frost Tolerance ◽  
Leaf Damage ◽  
Alternative Methods ◽  
Small Samples ◽  
Leaf Discs ◽  
Relative Conductivity ◽  
Highly Correlated

Improvements in a laboratory technique and statistical methods for screening eucalypts for relative frost tolerance using small samples of leaf tissue are described. As a contribution to more efficient genetic selection in a breeding program, these methods aim to provide reliable estimates of relative frost tolerance for ranking genotypes and to allow partitioning of total variation into components due to provenances, families, and individuals. Examination of sampling strategies indicated that four leaf discs per seedling at three frosting temperatures and 10 seedlings per family provided highly reliable estimates of frost tolerance. Mean relative conductivity values were found to be highly correlated with mean leaf damage sustained by a seedling across the whole range of values. Alternative methods of data analysis are compared. Estimation of LD50 values (the temperature at which 50% of leaf discs would be killed) and calculation of percent survival of leaf discs were found to be less efficient means of data analysis than directly analysing relative conductivity values. The nature of genetic control of frost tolerance and the assumptions underlying such nondestructive screening techniques are examined.

The Reproductive Ecology of Canavalia rosea (Fabaceae) on Anak Krakatau, Indonesia

1993 ◽  
Vol 41 (5) ◽  
pp. 591 ◽  
Author(s):  
CL Gross
Keyword(s):  
Plant Species ◽  
Breeding System ◽  
Fruit Set ◽  
Fold Increase ◽  
Fruiting Phenology ◽  
Resource Limited ◽  
Pioneer Plant ◽  
Floral Visitors ◽  
Low Levels ◽  
Resource Levels

Pioneer plant species are expected to have higher fruit-to-flower ratios than plants found in more established habitats. This was not found to be the case with Canavalia rosea on Anak Krakatau, Indonesia. Canavalia rosea is a pantropical pioneer plant species of beach habitats. On Anak Krakatau fruit-set in C. rosea in July 1992 ranged between 10 and 19% and a study of pollination and resource levels was undertaken to determine the cause of low fruit-to-flower ratios. An examination of flowering and fruiting phenology, breeding system and floral visitors revealed that low fruit-set in the population could not be explained by either a lack of pollinators or low levels of deposited pollen. Experimental removal of pods resulted in a near five-fold increase in fruit-set on subsequent flowers on treated plants compared with natural levels, indicating that fruit-set was resource limited. Low fruit-to-flower ratios do not detract from the colonising success of this species however, because individual plants flower prolifically year-round ensuring a constant production of propagules.

scholarly journals Initial decomposition of floating leaf blades of waterlilies: causes, damage types and impacts

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7158 ◽  
Author(s):  
Peter F. Klok ◽  
Gerard van der Velde
Keyword(s):  
Leaf Tissue ◽  
Nutrient Status ◽  
Phytopathogenic Fungi ◽  
Leaf Length ◽  
Leaf Damage ◽  
Invertebrate Species ◽  
Nymphaea Alba ◽  
Mechanical Factors ◽  
Floating Leaves ◽  
Floating Leaf

The initial decomposition of large floating-leaved macrophytes, such as waterlilies, can be studied by following changes in leaf damage and area loss of leaf blades tagged in their natural environment. This approach was taken in the present study to examine the initial decomposition patterns of floating leaf blades of Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida C. Presl at three freshwater sites differing in nutrient status, alkalinity and pH. Floating leaf blades of the three plant species were tagged and numbered within established replicate plots and the leaf length, percentages and types of damage and decay of all tagged leaves were recorded weekly during the growing season. Microbial decay, infection by phytopathogenic fungi (Colletotrichum nymphaeae) and oomycetes (Pythium sp.), consumption by pond snails, and mechanical factors were the most important causes of leaf damage. Several types of succession comprising different causes of damage were distinguished during the season. For example, young floating leaves are affected by more or less specialized invertebrate species consuming leaf tissue, followed by non-specialized invertebrate species feeding on the damaged floating leaves. In the two investigated hardwater lakes the seasonal patterns of initial decomposition differed between Nymphaea and Nuphar.

scholarly journals Assessment of Azotobacter chroococcum’s Ability to Produce Hydrolytic Enzymes and Enhance Growth of Vicia faba

2019 ◽  
Vol 16 (1) ◽  
pp. 0034
Author(s):  
Hutaf A. A Alsalim
Keyword(s):  
Vicia Faba ◽  
Root Length ◽  
Plant Root ◽  
Control Plant ◽  
Hydrolytic Enzymes ◽  
Shoot Length ◽  
Control Treatment ◽  
Sterile Soil ◽  
Npk Fertilizer ◽  
Growth Indicators

A. chroococcum isolate was examined for its ability to produce the hydrolytic enzymes chitinase, pectinase, protease, and lipase, in an effort to enhance the growth of fava bean (Vicia faba). Biological experiment was conducted in pots with complete random design (CRD). The experiment includes three treatments: control (plant without treatment) (P), NPK fertilizer (plant + fertilizer) (PF), and A. chroococcum inoculum (plant + A. chroococcum) (PA). These treatments were performed with sterile and non-sterile soil, which were planted with fava beans. At the end of experiment (seven weeks from planting), length and weight of plant shoot and plant root were calculated. The results show that the isolate was able to produce chitinase, pectinase, protease, and lipase enzymes. Plant growth increased with fertilizer and A. chroococcum inoculum addition. Fertilizer treatments (PF) were the best growth indicators, with the averages of shoot length and weight, and root length and weight of 19.52 cm, 15.55 gm, 19.93 cm, and 10.52 gm respectively.  The averages of these indicators in A. chroococcum treatment (PA) were 16.4 cm, 8.85 gm, 17.52 cm, and 6.88 gm respectively. The percentages of increase caused by A. chroococcum inoculum addition (PA) in contrast with control treatment (P) were 12.83% and 34.4% in plant shoot length and weight respectively, and 60.98% and 38.99% in plant root length and weight. In general, growth indicators were higher in non-sterile than sterile soil, but these increases were not significant

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