The responses of tsetse flies (Diptera, Glossinidae) to mobile and stationary baits

1974 ◽  
Vol 64 (4) ◽  
pp. 545-588 ◽  
Author(s):  
G. A. Vale
Keyword(s):  
Visual Stimuli ◽  
Field Studies ◽  
Nutritional State ◽  
Food Sources ◽  
Tsetse Flies ◽  
Conventional View ◽  
Initial Attraction ◽  
Food Seeking ◽  
Final Orientation

AbstractIn Rhodesia, field studies were made of the initial attraction of G. morsitans morsitans Westw. and G. pallidipes Aust. to mobile and stationary baits, using flight traps which surrounded baits or which were placed in the densest part of the attracted swarm. With stationary baits, many flies were attracted by host odour and visual stimuli assisted final orientation. With mobile baits, many flies were attracted by visual stimuli alone; odour did not increase attraction. With both mobile and stationary baits, there was no indication that major hosts are much more effective than minor ones as initial attractants, although stationary men were exceptionally poor baits, for G. pallidipes especially. The sex and species compositions of catches from stationary baits other than men were representative roughly of the inactive population—70% females of both species, and a roughly 1:4 ratio of G. morsitans to G. pallidipes. The sex and species compositions of catches from all mobile baits were biased—40% female G. morsitans, 60% female G. pallidipes, and a roughly 2:1 species ratio. Nearly all flies attracted to stationary baits were hungry whereas 10–25% of both sexes visiting mobile baits had fed recently. The use of a variety of electrocuting devices showed that compact persistent responses and alighting reactions of attracted flies were evident more for males than for females, more for G. morsitans than for G. pallidipes, more near model animals with host odour than near odourless models, more near models than near men, and more with tenerals and hungry non-tenerals than with recently fed flies. Men with mobile baits depressed greatly the alighting reactions and with stationary baits men inhibited greatly the initial attractions. Both effects of men were greater with females than with males and greater with G. pallidipes than with G. morsitans. Men were recognised by their upright appearance and odour. Only desperately hungry flies probed men whereas less-hungry flies probed an ox with men. Food-seeking flies of differing nutritional state were not shown to distinguish between mobile and stationary baits. Although the results support the conventional view that mating and feeding functions in the response to hosts occupy distinct phases of the hunger cycle, it seems necessary to modify the conventional view by placing more emphasis on the role of mobile baits as food sources and by envisaging a definite mate-seeking response by mature females.

Blame Avoidance in China's Cadre Responsibility System

2021 ◽  
pp. 1-22
Author(s):  
Jiayuan Li ◽  
Xing Ni ◽  
Rui Wang
Keyword(s):  
Qualitative Data ◽  
Performance Standards ◽  
Field Studies ◽  
Future Research ◽  
Limited Attention ◽  
Discursive Strategies ◽  
Conventional View ◽  
Blame Avoidance ◽  
Local Officials ◽  
Responsibility System

Abstract This article contends that prior research on the behaviour of Chinese local cadres pays limited attention to their motivation for avoiding blame. Using qualitative data from three field studies conducted in Guangdong province, the study focuses on blame avoidance in the cadre responsibility system, which is recognized as an important instrument for state capacity building. Our analysis uncovers three major discursive strategies used by grassroots cadres to manage blame either before or after it is apportioned: de-legitimating performance standards, re-attributing blame and transferring blame risk. We find that local cadres have a role as blame makers in shifting blame and accusations. This finding challenges the conventional view, which typically sees local officials as blame takers. The article concludes by elaborating on the wider implications of this finding and proposing avenues for future research.

Methyl mercury in zooplankton—the role of size, habitat, and food quality

2002 ◽  
Vol 59 (10) ◽  
pp. 1606-1615 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Body Size ◽  
Methyl Mercury ◽  
Size Fraction ◽  
Food Sources ◽  
Calanoid Copepods ◽  
Bacterial Food

Pathways of methyl mercury (MeHg) accumulation in zooplankton include ingestion of organic matter (OM). We analyzed fatty acid (FA) biomarkers in zooplankton to (i) investigate the effect of allochthonous and autochthonous OM ingestion on MeHg concentrations ([MeHg]) in zooplankton and (ii) examine how algal and bacterial food sources affect MeHg bioaccumulation. We partitioned bulk zooplankton samples (i.e., >500, 202, 100, and 53 μm) from Lake Lusignan (Québec) and measured [MeHg] and [FA] in each fraction. [MeHg] increased with increasing body size and was significantly higher in pelagic than in littoral macrozooplankton (>500 μm). The amount of the ingested terrestrial FA biomarker 24:0 indicated that less than 1% of the total FA in zooplankton was derived from allochthonous sources. More than 60% of the ingested FA originated from algal biomarkers and <10% from bacterial biomarkers. Relative amounts of algal-derived essential FA and bacterial FA were not associated with [MeHg] in any size fraction. In pelagic zones, the amount of MeHg in zooplankton related positively to the number of large organisms such as Calanoid copepods and Daphnia. We propose that the accumulation of MeHg in lacustrine zooplankton depends on the zooplankton habitat rather than on the quality of ingested food.

Responses of tsetse flies (Diptera: Glossinidae) to odour-baited trees

1991 ◽  
Vol 81 (3) ◽  
pp. 323-331 ◽  
Author(s):  
G. A. Vale
Keyword(s):  
Field Studies ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Free Standing ◽  
Model Trees ◽  
Clear Effect

AbstractField studies in Zimbabwe elucidated how trees might be enhanced as baits for controlling Glossina morsitans morsitans Westwood and G. pallidipes Austen. Catches from electrocuting devices at the bases of trees were near nil when sampling tsetse flies landing on the trunk but much greater when sampling them flying within 1 m of the trunk. Catches increased 5–8 times when 2 m2 of the trunk were blackened and given odour of acetone, 1-octen-3-ol, 3-n-propyl phenol and 4-methyl phenol, but were still only ca. 30% of the catches from an odour-baited, free-standing, 1 × 1 m screen of black cloth. The upright trunk of real and model trees hindered their attractiveness but leaves and branches 5 m above ground had no clear effect. Real and artificial stumps of trees were as effective as the screen if they were 1 m2, compact and sharply outlined. The practical and biological implications of the results are discussed, with particular reference to the use of insecticide-treated netting with modified tree stumps as baits for control.

scholarly journals Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory

2018 ◽  
Vol 18 (18) ◽  
pp. 13321-13328
Author(s):  
Pertti Hari ◽  
Steffen Noe ◽  
Sigrid Dengel ◽  
Jan Elbers ◽  
Bert Gielen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Boreal Forests ◽  
Co2 Flux ◽  
Field Studies ◽  
Co2 Assimilation ◽  
Co2 Fluxes ◽  
New Era ◽  
Evergreen Forests ◽  
Transition Times

Abstract. Photosynthesis provides carbon for the synthesis of macromolecules to construct cells during growth. This is the basis for the key role of photosynthesis in the carbon dynamics of ecosystems and in the biogenic CO2 assimilation. The development of eddy-covariance (EC) measurements for ecosystem CO2 fluxes started a new era in the field studies of photosynthesis. However, the interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in transition times such as the spring and autumn. We apply two theoretical needle-level equations that connect the variation in the light intensity, stomatal action and the annual metabolic cycle of photosynthesis. We then use these equations to predict the photosynthetic CO2 flux in five Scots pine stands located from the northern timberline to Central Europe. Our result has strong implications for our conceptual understanding of the effects of the global change on the processes in boreal forests, especially of the changes in the metabolic annual cycle of photosynthesis.

scholarly journals Analysis of the Role of Parent’s Lifestyle by the Authoritative Parenting Style in Girls of Grade Three of High School in Zahedan: A Cross Sectional Study

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Azam Akbarizadeh ◽  
Khadijeh Khoeini
Keyword(s):  
High School ◽  
Parenting Style ◽  
Field Studies ◽  
Cross Sectional Study ◽  
Sample Volume ◽  
Authoritative Parenting ◽  
Cross Sectional ◽  
Authoritative Parenting Style ◽  
Political Economic

Background: Every family applies a certain educational style in individual and social education of their children. These styles are influenced by many factors, including cultural, social, political, economic styles, etc. The parents’ lifestyle is one of styles that have a great impact on parenting. In this regard, the goal of present research is analysis of the role of parent’s lifestyle by the authoritative parenting style. Methods: The research method is descriptive-analytic based on library, documentary and field studies. Statistical Society of the research is all intelligent girls of grade three in high school of Zahedan during 2015-2016 school years. Cochran formula has been used to determine the sample volume which 311 people were estimated. Spearman statistical methods and multiple regressions have been used to analyze the data. Results: The results of the research show that the lifestyle and its components have a significant correlation with authoritative parenting style and can predict it. Conclusion: The findings of this study, while having applicable aspects in this domain, can be helpful in planning supplementary remedial procedures.

scholarly journals The Role Of NGOs In Community Development In Balochistan

2016 ◽  
Vol 4 (1) ◽  
pp. 123-135
Author(s):  
Siraj Bashir
Keyword(s):  
Community Development ◽  
Social Services ◽  
Field Studies ◽  
Living Standard ◽  
Development Programs ◽  
Governmental Organizations ◽  
Local Resources ◽  
Non Governmental Organizations ◽  
Private Organization

Community Development (CD) is an approach aimed at improving the quality of life of the community. The approach for improvement can be achieved through a number of ways and organizations which includes, the Governmental and Non-Governmental Organizations (NGOs). Non- Governmental Organizations (NGOs) "a private organization that pursue activities to reduce suffering, promote the interest of the poor , protect the environment, provide basic social services or undertake community development". This paper discusses the role and contribution of NGOs towards development in Balochistan. NGOs have several projects, programs and roles which support people to bring development in communities. In addition, NGOs mobilize the communities to be self-dependent. The study includes interviews, document analysis and field studies with staffs and the beneficiaries of NGOs. The study helps the communities to find out their own problems and solve them according to their own local resources. Recommendations made as to the best practices of community development programs for NGOs to improve the living standard of people in province of Balochistan.

scholarly journals Application of immobilized mycelium-based pellets for the removal of organochlorine compounds: a review

2021 ◽  
Author(s):  
J. C. V. Pereira ◽  
M. P. Serbent ◽  
E. Skoronski
Keyword(s):  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Field Studies ◽  
Organochlorine Compounds ◽  
Environmental Persistence ◽  
Factors Affecting ◽  
Materials Used ◽  
Immobilization Techniques ◽  
Enzymatic Machinery

Abstract Organochlorines have diverse structures and applications and are included in the list of persistent organic pollutants (POPs) due to their toxicity and environmental persistence. The reduced capacity of conventional wastewater treatment plants to remove these compounds encourages the development of cost-effective and efficient remediation approaches. Fungal biotechnology can contribute to the development of these technologies through their enzymatic machinery but faces several drawbacks related to the use of dispersed mycelium. In this sense, investigations concerning the degradation of organochlorines using immobilized fungi demonstrated an increase in contaminants removal efficiency compared with degradation by free cells. Despite this interest, the mechanisms of immobilized fungi have not been comprehensively reviewed. In this paper, recent advances of laboratory and field studies in organochlorine compounds removal by fungi were reviewed, focusing on the role of immobilization techniques. Firstly, the mechanisms of organochlorines bioconversion by fungi and the factors affecting enzyme activity are elucidated and discussed in detail. Then, the main targeted compounds, fungi, technics, and materials used for immobilization are discussed, as well as their advantages and limitations. Furthermore, critical points for future studies of the fungi immobilization for organochlorines removal are proposed.

scholarly journals The role of termite CH<sub>4</sub> emissions on ecosystem scale: a case study in the Amazon rain forest

2020 ◽  
Author(s):  
Hella van Asperen ◽  
João Rafael Alves-Oliveira ◽  
Thorsten Warneke ◽  
Bruce Forsberg ◽  
Alessandro Carioca de Araujo ◽  
...  
Keyword(s):  
Rain Forest ◽  
Emission Factor ◽  
Field Studies ◽  
Ch4 Emission ◽  
Termite Mound ◽  
Flux Chamber ◽  
Termite Mounds ◽  
Ch4 Emissions ◽  
Amazon Rain Forest

Abstract. The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in-situ CH4 emission measurements of termite mounds and termite mound sub samples, performed in the Amazon rain forest. Emissions of five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser, measuring CH4 and CO2. In addition, the emission of mound sub samples was measured, after which termites were counted, so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0–34.8 nmol mound−1 s−1 for CH4 and between 1.6–13.5 μmol mound−1 s−1 for CO2. A termite emission factor of 0.32 μmol CH4 gtermite−1 h−1 was found, which is twice as high as the only other reported average value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 50–120 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystems CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local termite mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1 on average emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite density numbers, resulting in an estimate of termite emitted CH4 of ~1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this Terra Firme ecosystem.

scholarly journals The role of new stress protectors in the formation of production process of oat culture during cultivation in anthropogenically polluted areas

2020 ◽  
Vol 23 ◽  
pp. 03011
Author(s):  
Yuliya M. Andriyanova ◽  
Irina V. Sergeyeva ◽  
Nataliya N. Gusakova ◽  
Yuliya M. Mokhonko
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Negative Impact ◽  
Field Studies ◽  
Amylolytic Enzymes ◽  
Cereal Products ◽  
Oat Seeds ◽  
Lead Zinc

Stress protectors (adaptogens) are among the most important factors that regulate growth processes at all stages of plant development. This article presents results of field studies of the effect of new synthetic plant growth regulators of stress protectors (adaptogens) on the elements of productivity and yield of spring oats of the Skakun variety. The obtained results during the research showed that all the studied derivatives of peredazinones are adaptogens and they contribute to an increased productivity and increased yield of spring oats. We studied the effect of pre-sowing treatment of seeds with new synthetic plant growth regulators of stress protectors on the quality indicators of cereal production of Skakun oats (protein, starch and amylolytic enzymes content in the cereal). Pre-sowing treatment of oat seeds increases the amount of protein in the cereal up to 15%, starch – up to 25%, amylase – up to 20%. We proved the ability of stress protectors to minimize the negative impact of heavy metals (lead, zinc) on agrophytocenoses, which will make it possible to obtain environmentally friendly cereal products when cultivating oats in anthropogenically polluted areas of the Saratov Oblast.

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