Long-term effects on cowpea plant growth of a short-term cowpea aphid infestation

1986 ◽  
Vol 64 (8) ◽  
pp. 1727-1732 ◽  
Author(s):  
C. D. B. Hawkins ◽  
M. I. Whitecross ◽  
M. J. Aston
Keyword(s):  
Compensatory Growth ◽  
Detectable Effect ◽  
Long Term Effects ◽  
Aphid Infestation ◽  
Relative Growth Rates ◽  
Unit Leaf ◽  
Aphis Craccivora Koch ◽  
Experimental Treatments ◽  
Induced Changes

Two-week-old cowpea seedlings (Vigna unguiculata (L.) Walp.) were infested with cowpea aphids (Aphis craccivora Koch (Homoptera: Aphididae)) for 5, 10, 15, and 20 days at which time the aphids were removed with a systemic insecticide. The seedlings were then allowed to grow for another 3 months. By day 10, plant dry weights, mean relative growth rates [Formula: see text], and mean unit leaf rates (Ē) were all significantly reduced in the infested plants, and these relationships still held at day 20. Apparent decreases in photosynthesis and (or) increases in respiration were the primary causes of these reductions. There were no significant differences between control and experimental treatments for [Formula: see text] calculated from day 0, and total number of seeds and seed pods produced at the end of the study. Control plants had significantly more mature seed pods and seeds, while formerly infested plants had significantly more mature and unripe seeds per pod, more unripe seed pods and seeds produced, and greater values for [Formula: see text] from the time of aphid removal until the end of the experiment. This latter increase in [Formula: see text] indicates a form of compensatory growth. It is proposed that the compensatory growth of previously infested plants and ultimate similarity in seed production, as compared with control plants, may have resulted from aphid-induced changes via nonhormonal compounds acting as phytohormone regulators. The different durations of aphid infestation used had no detectable effect on long-term growth.

Aphid-induced changes in growth indices of three leguminous plants: unrestricted infestation

1985 ◽  
Vol 63 (12) ◽  
pp. 2454-2459 ◽  
Author(s):  
C. D. B. Hawkins ◽  
M. J. Aston ◽  
M. I. Whitecross
Keyword(s):  
Acyrthosiphon Pisum ◽  
Growth Patterns ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Unit Leaf ◽  
Aphis Craccivora Koch ◽  
The Mean ◽  
Net Assimilation ◽  
Induced Changes ◽  
And Control

The effects of various densities of cowpea aphids (Aphis craccivora Koch) and pea aphids (Acyrthosiphon pisum Harris), both Homoptera: Aphididae, on the growth of cowpea (Vigna unguiculata (L.) Walp. cv. Caloona), broad bean (Vicia faba L. cv. Aquadulce), and garden pea (Pisum sativum L. cv. Victory Freezer) seedlings were investigated. Within 10 days of infestation, aphid feeding significantly reduced plant dry weights and mean relative growth rates for the six plant–aphid combinations. In all cases except one, the mean unit leaf or net assimilation rate was also significantly reduced within 10 days. The mean leaf area ratio was the same for infested and control plants. The aphid-induced changes in host plants appear to be due to changes in photosynthesis, respiration, and translocate removal from the phloem over the 10-day period. Changes in the growth patterns of the host plant within this period are similar, but the underlying physiological effects could vary among particular plant–aphid combinations.

scholarly journals Trastuzumab in the Treatment of Pregnant Breast Cancer Patients – an Overview of the Literature

2019 ◽  
Vol 79 (06) ◽  
pp. 618-625 ◽  
Author(s):  
Sophia S. Goller ◽  
Udo R. Markert ◽  
Karolin Fröhlich
Keyword(s):  
Breast Cancer ◽  
Breast Cancers ◽  
Breast Cancer Patients ◽  
Long Term Effects ◽  
The Future ◽  
Systemic Adjuvant Therapy ◽  
Induced Changes ◽  
Available Information ◽  
Target Agent

AbstractBreast cancer is one of the most common malignancies which appear during pregnancy. Since women are increasingly not giving birth until they are at a more advanced age, it can be assumed that the incidence of pregnancy-related breast cancers will continue to increase in the future. Because of pregnancy-induced changes and conservative diagnosis, these carcinomas are frequently not detected until they are at an advanced stage and thus generally require systemic adjuvant therapy. The available data on optimal chemotherapeutic management are limited. Particularly for the use of the target agent trastuzumab which could crucially contribute to improving the prognosis in the therapy of HER2-overexpressing breast cancer in non-pregnant women, there is a lack of definitive information regarding the profile of action and safety in pregnancy as well as with regard to any long-term effects on the child. Thirty-eight pregnancies on trastuzumab for the treatment of breast cancer were able to be analysed in the literature currently available. Information can be gained from this and conclusions can be drawn which can individualise and decisively improve therapeutic options in the future for the pregnant breast cancer patient.

scholarly journals Relative Mass of Brain- and Intestinal Tissue in Juvenile Brown Trout: No Long-Term Effects of Compensatory Growth; with Additional Notes on Emerging Sex-Differences

Fishes ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 38
Author(s):  
Joacim Näslund
Keyword(s):  
Sex Differences ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Compensatory Growth ◽  
Fork Length ◽  
Relative Mass ◽  
Long Term Effects ◽  
Treatment Groups ◽  
Trade Offs

This study investigated whether compensatory growth causes long-term effects in relative brain- or intestine size in a wild, predominantly anadromous, population of brown trout (Salmo trutta). The subject fish belonged to two treatment groups; one group had undergone starvation and subsequent growth compensation, while the other were unrestricted controls. The main hypothesis that compensatory growth would negatively affect brain and intestinal size, as a consequence of growth trade-offs during the compensatory phase, could not be supported as no significant differences were detected between the treatment groups. Further exploratory analyses suggested that males and females started to diverge in both brain and intestine size at around 130 mm fork length, with females developing relatively smaller brains and larger intestines. The size at which the differences appear is a typical size for smoltification (saltwater preadaptation), and females tend to smoltify to a higher proportion than males. Smoltification is known to cause a more elongated morphology and relatively smaller heads in salmonids, and the marine lifestyle is associated with rapid growth, which could require relatively larger intestines. Hence, these emerging sex differences could be a consequence of sex-biased smoltification rates. An investigation of wild smolts of both sexes indicated no differences in brain or intestine mass between male and female smolts.

scholarly journals Long-term demographic consequences of a seed dispersal disruption

2012 ◽  
Vol 279 (1741) ◽  
pp. 3298-3303 ◽  
Author(s):  
Anna Traveset ◽  
Juan P. González-Varo ◽  
Alfredo Valido
Keyword(s):  
Long Term Effects ◽  
Ecological Processes ◽  
Cascading Effects ◽  
Island Populations ◽  
Mutualistic Interaction ◽  
Entire Plant ◽  
Local Extinctions ◽  
Long Term Consequences ◽  
Induced Changes

The loss or decline of vertebrate frugivores can limit the regeneration of plants that depend on them. However, empirical evidence is showing that this is still very scarce, as functionally equivalent species may contribute to maintain the mutualistic interaction. Here, we investigated the long-term consequences of the extinction of frugivorous lizards on the population persistence of a Mediterranean relict shrub Cneorum tricoccon (Cneoraceae). We examined the demographic parameters among 26 insular and mainland populations, which encompass the entire plant distributional range, comparing populations with lizards with those in which these are extinct, but in which alien mammals currently act as seed dispersers. Plant recruitment was found to be higher on island populations with lizards than on those with mammals, and the long-term effects of the native disperser's loss were found in all vital phases of plant regeneration. The study thus gives evidence of the cascading effects of human-induced changes in ecosystems, showing how the disruption of native ecological processes can lead to species regression and, in the long term, even to local extinctions.

scholarly journals The Impact of Sports-Related Concussions on the Language System

2018 ◽  
Vol 1 (1) ◽  
pp. 36-46
Author(s):  
Patrick S Ledwidge
Keyword(s):  
Brain Activity ◽  
Brain Regions ◽  
Functional Brain Imaging ◽  
Long Term Effects ◽  
Brain Potentials ◽  
Language System ◽  
Induced Changes ◽  
The Impact ◽  
Language Network

Sports-related Concussions (SRC) and their potential long-term effects are a growing concern among athletes and their families. Research utilizing functional brain imaging/recording techniques (e.g., fMRI, ERP) seeks to explain how neurocognitive brain activity changes in the days and years following SRC. Although language deficits are documented following non-sports related concussion there remains a striking lack of research on how SRCs may influence the language system and their supporting neural mechanisms. Neuroimaging findings, however, demonstrate that SRCs alter structural and functional pathways within the frontotemporal language network. Brain regions included in this network generate language-related event-related brain potentials (ERPs), including the N400 and P600. ERPs have been used to demonstrate long-term neurocognitive alterations associated with concussion and may also provide objective and robust markers of SRC-induced changes to the language system.

Periphyton response to long-term nutrient enrichment in a shaded headwater stream

2005 ◽  
Vol 62 (9) ◽  
pp. 2033-2045 ◽  
Author(s):  
Jennifer L Greenwood ◽  
Amy D Rosemond
Keyword(s):  
Growth Rates ◽  
Nutrient Enrichment ◽  
Algal Species ◽  
Light Availability ◽  
Algal Growth ◽  
Detectable Effect ◽  
Long Term Effects ◽  
Tree Canopies ◽  
Periphyton Biomass

We maintained elevated but moderate concentrations of nitrogen and phosphorus continuously for 2 years in a heavily shaded headwater stream and compared effects on stream periphyton with a reference stream. Both streams were sampled for 1 year before treatment. Some measures of periphyton biomass (ash-free dry mass and chlorophyll a) responded positively to enrichment. Increased chlorophyll a was likely a result of higher chlorophyll per cell, as total algal biovolume did not change with enrichment. These differences were greatest during high-light months (November-May), when cellular growth rates (a proxy for production) were also highest with enrichment. Algal assemblages were dominated by diatoms and remained similar between the treatment and reference streams throughout the enrichment period. Although nutrients stimulated algal growth rates, the long-term effects of nutrient addition on periphyton biomass were small in magnitude compared with other published values and were potentially suppressed by light availability and invertebrate consumption. These and other factors may have also been important in limiting the algal species pool and thus a taxonomic response to enrichment. Our results indicate that in headwater streams with intact tree canopies, chronic nutrient enrichment at moderate concentrations may have little detectable effect on benthic algal composition or periphyton biomass. Although nutrients stimulated algal growth rates, the long-term effects of nutrient addition on periphyton biomass were small in magnitude compared with other published values and were potentially suppressed by light availability and invertebrate consumption. These and other factors may have also been important in limiting the algal species pool and thus a taxonomic response to enrichment. Our results indicate that in headwater streams with intact tree canopies, chronic nutrient enrichment at moderate concentrations may have little detectable effect on benthic algal composition or periphyton biomass.

Long-term effects of anthropogenic habitat disturbance on a lizard assemblage inhabiting coastal dunes in Argentina

2000 ◽  
Vol 78 (9) ◽  
pp. 1653-1660 ◽  
Author(s):  
Laura E Vega ◽  
Patricio J Bellagamba ◽  
Lee A Fitzgerald
Keyword(s):  
Relative Abundance ◽  
Habitat Structure ◽  
Coastal Dunes ◽  
Microhabitat Use ◽  
Long Term Effects ◽  
Drastic Reduction ◽  
Anthropogenic Habitat ◽  
The Mean ◽  
Induced Changes

We studied abundance and habitat use in two species of Liolaemus (Squamata: Tropiduridae) at a coastal dune site in eastern Argentina before and 7 years after a road was built at the site. Before disturbance, lizards exhibited similar abundances and a wide segregation in microhabitat use. Liolaemus multimaculatus used flat dunes scarcely covered by Spartina ciliata, while Liolaemus gracilis used the grass Panicum racemosum as cover. After disturbance, the mean number of L. multimaculatus detected by month was significantly less than that observed in the predisturbance period, owing to a drastic reduction in S. ciliata microhabitat patches. The mean number of L. gracilis was similar to that seen during the first period. These differences were clearly linked to habitat loss at the site. We concluded that human impact on the habitat structure of foredunes induced changes in the structure of the lizard assemblage, including shifts in the relative abundance of species and the proportional use of their preferred microhabitats.

scholarly journals Evaluation of short-, mid- and long-term effects of toe clipping on a wild rodent

2015 ◽  
Vol 42 (2) ◽  
pp. 143 ◽  
Author(s):  
Benny Borremans ◽  
Vincent Sluydts ◽  
Rhodes H. Makundi ◽  
Herwig Leirs
Keyword(s):  
Detectable Effect ◽  
Small Rodent ◽  
Mastomys Natalensis ◽  
Long Term Effects ◽  
Wild Rodent ◽  
Ethical Guidelines ◽  
Free Living ◽  
First Time ◽  
Multimammate Mice

Context Toe clipping is a widely used method for permanent marking of small mammals, but its effects are not well known, despite the ethical and scientific implications. Most studies do not find any clear effects, but there is some indication that toe clipping can affect survival in specific cases. Although effects on survival are arguably the most important, more subtle effects are also plausible, yet very few studies have included body condition and none has investigated effects on mobility. Aims We analysed the effects of toe clipping on free-living Mastomys natalensis, a common, morphologically and behaviourally intermediate small rodent. Methods Using a 17-year capture–mark–recapture dataset, we compared movement, body weight and survival between newly and previously clipped animals, and tested whether any of these parameters correlated with the number of clipped toes. Key results No evidence for a correlation between total number of clips and any of the variables was found. Newly clipped animals had a slightly smaller weight change and larger travel distance than did those that were already clipped, and we show that this is most likely due to stress caused by being captured, clipped and handled for the first time rather than to the actual clipping. Conclusions The combination of trapping, handling and marking has a detectable effect on multimammate mice; however, there is no evidence for a clear effect of toe clipping. Implications Our study suggests a re-evaluation of ethical guidelines on small-mammal experiments, so as to reach a rational, fact-based decision on which marking method to use.

Interactions between aphid infestation and plant growth and uptake of nitrogen and phosphorus by three leguminous host plants

1986 ◽  
Vol 64 (10) ◽  
pp. 2362-2367 ◽  
Author(s):  
C. D. B. Hawkins ◽  
M. I. Whitecross ◽  
M. J. Aston
Keyword(s):  
Acyrthosiphon Pisum ◽  
Dry Weight ◽  
P Uptake ◽  
Nitrogen And Phosphorus ◽  
Aphid Infestation ◽  
Unit Leaf ◽  
Pea Aphids ◽  
Aphis Craccivora Koch ◽  
Aphid Feeding ◽  
Species Specific

The effects of cowpea aphids (Aphis craccivora Koch) and pea aphids (Acyrthosiphon pisum (Harris)), both Homptera: Aphididae, on nitrogen (N) and phosphorus (P) uptake by and growth of cowpea (Vigna unguiculata (L.) Walp. cv. Caloona), broad bean (Vicia faba L. cv. Aquadulce), and garden pea (Pisum sativum L. cv. Victory Freezer) seedlings were investigated. After 10 days of aphid infestation, all leaf areas were significantly lower in infested plants, and plant dry weight, mean relative growth rate, and unit leaf rate were significantly lower in all plant–aphid combinations except for pea – pea aphids. The mean leaf area ratio was the same for infested and control plants indicating that infested plants did not reallocate their assimilate resources in response to aphid feeding. The accumulation of N and P as a percentage of plant dry weight did not differ between control and infested plants and was specific to the species examined. However, control plants all had greater absolute amounts of N and P after 10 days. Even though the responses of the plants to aphid feeding were similar, the accumulation of N and P appears to be a plant species specific phenomenon.

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