Survival and Reproduction of the Corn Leaf Aphid on Twelve Maize Genotypes

1967 ◽  
Vol 60 (2) ◽  
pp. 527-530 ◽  
Author(s):  
A. M. Rhodes ◽  
W. H. Luckmann
Keyword(s):  
Maize Genotypes ◽  
Corn Leaf Aphid ◽  
Survival And Reproduction

Structure-Reactivity Relationships on Substrates and Inhibitors of the Lysine Deacylase Sirtuin 2 from Schistosoma Mansoni (SmSirt2)

2019 ◽  
Author(s):  
Daria Monaldi ◽  
Dante Rotili ◽  
Julien Lancelot ◽  
Martin Marek ◽  
Nathalie Wössner ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Human Cancer ◽  
Egg Laying ◽  
Human Cancer Cells ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Emergence Of Resistance ◽  
First Time ◽  
Parasitic Life Cycle

The only drug for treatment of Schistosomiasis is Praziquantel, and the possible emergence of resistance makes research on novel therapeutic agents necessary. Targeting of Schistosoma mansoni epigenetic enzymes, which regulate the parasitic life cycle, emerged as promising approach. Due to the strong effects of human Sirtuin inhibitors on parasite survival and reproduction, Schistosoma sirtuins were postulated as therapeutic targets. In vitro testing of synthetic substrates of S. mansoni Sirtuin 2 (SmSirt2) and kinetic experiments on a myristoylated peptide demonstrated lysine long chain deacylation as an intrinsic SmSirt2 activity for the first time. Focused in vitro screening of the GSK Kinetobox library and structure-activity relationships (SAR) of identified hits, led to the first SmSirt2 inhibitors with activity in the low micromolar range. Several SmSirt2 inhibitors showed potency against both larval schistosomes (viability) and adult worms (pairing, egg laying) in culture without general toxicity to human cancer cells.<br>

Effect of phosphorus stress on the pigment and morphology of different maize genotypes

2009 ◽  
Vol 17 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Jun-Yi CHEN ◽  
Yi-Lin CAI ◽  
Li XU ◽  
Zhi-Guo YANG ◽  
Xiao-Ling GAN ◽  
...  
Keyword(s):  
Phosphorus Stress ◽  
Maize Genotypes

Root Morphology of Contrasting Maize Genotypes

2002 ◽  
Vol 94 (1) ◽  
pp. 96 ◽  
Author(s):  
Carlos Costa ◽  
Lianne M. Dwyer ◽  
Xiaomin Zhou ◽  
Pierre Dutilleul ◽  
Chantal Hamel ◽  
...  
Keyword(s):  
Root Morphology ◽  
Maize Genotypes

Brains as Engines of Association

2019 ◽  
Author(s):  
Dale Purves
Keyword(s):  
Neural Systems ◽  
Neural Function ◽  
Trial And Error ◽  
Nervous Systems ◽  
The Past ◽  
Sensing Systems ◽  
Lifetime Experience ◽  
Survival And Reproduction ◽  
Pros And Cons ◽  
And Behavior

Brains as Engines of Association seeks an operating principle of the human brain and is divided into four parts. The first part (“What Nervous Systems Do for Animals”) is intended to set the stage for understanding the emergence of neural systems as promoting what all organisms must accomplish: survival and reproduction. The second part (“Neural Systems as Engines of Association”) lays out the general argument that biological sensing systems face a daunting problem: they cannot measure the parameters of the world in the way physical instruments can. As a result, nervous systems must make and update associations (synaptic connections) on the basis of empirical success or failure over both evolutionary and individual time. The third part (“Evidence that Neural Systems Operate Empirically”) reviews evidence accumulated over the past 20 years that supports this interpretation in vision and audition, the sensory systems that have been most studied from this or any other perspective. Finally, the fourth part (“Alternative Concepts of Neural Function”) considers the pros and cons of other interpretations of how brains operate. The overarching theme is that the nervous systems of humans and every other animal operate on the basis associations between stimuli and behavior made by trial and error over species and lifetime experience.

Inbreeding reduces reproductive fitness

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Natural Selection ◽  
Inbreeding Depression ◽  
Reproductive Fitness ◽  
Heterozygote Advantage ◽  
Small Populations ◽  
Population Bottlenecks ◽  
Risk Of Extinction ◽  
Survival And Reproduction

The harmful impacts of inbreeding are generally greater in species that naturally outbreed compared to those in inbreeding species, greater in stressful than benign environments, greater for fitness than peripheral traits, and greater for total fitness compared to its individual components. Inbreeding reduces survival and reproduction (i.e., it causes inbreeding depression), and thereby increases the risk of extinction. Inbreeding depression is due to increased homozygosity for harmful alleles and at loci exhibiting heterozygote advantage. Natural selection may remove (purge) the alleles that cause inbreeding depression, especially following inbreeding or population bottlenecks, but it has limited effects in small populations and usually does not completely eliminate inbreeding depression. Inbreeding depression is nearly universal in sexually reproducing organisms that are diploid or have higher ploidies.

scholarly journals Adaptive mechanisms driving maladaptive pain: how chronic ongoing activity in primary nociceptors can enhance evolutionary fitness after severe injury

2019 ◽  
Vol 374 (1785) ◽  
pp. 20190277 ◽  
Author(s):  
Edgar T. Walters
Keyword(s):  
Chronic Pain ◽  
Motor Impairment ◽  
Low Frequency ◽  
Severe Injury ◽  
Ongoing Activity ◽  
Pain Mechanisms ◽  
Bodily Injury ◽  
Adaptive Mechanisms ◽  
Survival And Reproduction ◽  
Ongoing Pain

Chronic pain is considered maladaptive by clinicians because it provides no apparent protective or recuperative benefits. Similarly, evolutionary speculations have assumed that chronic pain represents maladaptive or evolutionarily neutral dysregulation of acute pain mechanisms. By contrast, the present hypothesis proposes that chronic pain can be driven by mechanisms that evolved to reduce increased vulnerability to attack from predators and aggressive conspecifics, which often target prey showing physical impairment after severe injury. Ongoing pain and anxiety persisting long after severe injury continue to enhance vigilance and behavioural caution, decreasing the heightened vulnerability to attack that results from motor impairment and disfigurement, thereby increasing survival and reproduction (fitness). This hypothesis is supported by evidence of animals surviving and reproducing after traumatic amputations, and by complex specializations that enable primary nociceptors to detect local and systemic signs of injury and inflammation, and to maintain low-frequency discharge that can promote ongoing pain indefinitely. Ongoing activity in nociceptors involves intricate electrophysiological and anatomical specializations, including inducible alterations in the expression of ion channels and receptors that produce persistent hyperexcitability and hypersensitivity to chemical signals of injury. Clinically maladaptive chronic pain may sometimes result from the recruitment of this powerful evolutionary adaptation to severe bodily injury. This article is part of the Theo Murphy meeting issue ‘Evolution of mechanisms and behaviour important for pain’.

scholarly journals A Preliminary Assessment of Amblyseius andersoni (Chant) as a Potential Biocontrol Agent against Phytophagous Mites Occurring on Coniferous Plants

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 664
Author(s):  
Ewa Puchalska ◽  
Stanisław Kamil Zagrodzki ◽  
Marcin Kozak ◽  
Brian G. Rector ◽  
Anna Mauer
Keyword(s):  
Biocontrol Agent ◽  
Mass Rearing ◽  
Predator Population ◽  
Preliminary Assessment ◽  
Amblyseius Andersoni ◽  
Food Items ◽  
Oligonychus Ununguis ◽  
Potential Biocontrol Agent ◽  
Pine Pollen ◽  
Survival And Reproduction

Development, survival and reproduction of Ambyseius andersoni (Chant), a predatory mite widely distributed in Europe, were assessed on different food items. These included two key pests of ornamental coniferous plants, i.e., Oligonychus ununguis (Jacobi) and Pentamerismus taxi (Haller) and pollen of Pinus sylvestris L. The rationale behind these experiments was to provide a preliminary assessment of the potential of A. andersoni as a biocontrol agent of the above phytophagous arthropods and evaluate pine pollen as an alternative food source for the predator. Under laboratory conditions (23 ± 0.5 °C, 70 ± 10% RH and 16L:8D) A. andersoni was able to feed, develop and reproduce on all tested diets. The shortest development time (egg to female) was obtained when the predator fed on P. taxi (mean = 5.12 d) and the longest was on pine pollen (mean = 6.55 d). The rm value was significantly higher on both tested prey (0.166 on P. taxi and 0.160 on O. ununguis) than on pollen (0.139). Thus, we do not recommend pine pollen for mass rearing of A. andersoni; however, we conclude that pollen may provide sufficient sustenance for the predator population under field conditions when prey are absent. The potential of A. andersoni as a biocontrol agent of O. ununguis and P. taxi is discussed.

scholarly journals Production Performance of Moina macrocopa (Straus 1820) (Crustacea, Cladocera) Cultured in Different Salinities: The Effect on Growth, Survival, Reproduction, and Fatty Acid Composition of the Neonates

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 105
Author(s):  
Amirah Yuslan ◽  
Sharifah Najuwa ◽  
Atsushi Hagiwara ◽  
Mazlan A. Ghaffar ◽  
Hidayu Suhaimi ◽  
...  
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Production Performance ◽  
Reproduction Rate ◽  
Moina Macrocopa ◽  
Polyunsaturated Fatty Acid Content ◽  
Survival And Reproduction

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8.

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