scholarly journals Long-term effects of neonicotinoid insecticides on ants

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Daniel Schläppi ◽  
Nina Kettler ◽  
Lars Straub ◽  
Gaétan Glauser ◽  
Peter Neumann
Keyword(s):  
Chronic Exposure ◽  
Risk Assessments ◽  
Lasius Niger ◽  
Long Term Effects ◽  
Ant Colonies ◽  
Trade Off ◽  
Neonicotinoid Insecticides ◽  
Detoxification System ◽  
Ecological Risk Assessments

AbstractThe widespread prophylactic usage of neonicotinoid insecticides has a clear impact on non-target organisms. However, the possible effects of long-term exposure on soil-dwelling organisms are still poorly understood especially for social insects with long-living queens. Here, we show that effects of chronic exposure to the neonicotinoid thiamethoxam on black garden ant colonies, Lasius niger, become visible before the second overwintering. Queens and workers differed in the residue-ratio of thiamethoxam to its metabolite clothianidin, suggesting that queens may have a superior detoxification system. Even though thiamethoxam did not affect queen mortality, neonicotinoid-exposed colonies showed a reduced number of workers and larvae indicating a trade-off between detoxification and fertility. Since colony size is a key for fitness, our data suggest long-term impacts of neonicotinoids on these organisms. This should be accounted for in future environmental and ecological risk assessments of neonicotinoid applications to prevent irreparable damages to ecosystems.

scholarly journals A systematic review of neuroimaging and acute cannabis exposure in age-of-risk for psychosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lani Cupo ◽  
Eric Plitman ◽  
Elisa Guma ◽  
M. Mallar Chakravarty
Keyword(s):  
Chronic Exposure ◽  
Brain Regions ◽  
Acute Exposure ◽  
Psychotic Symptoms ◽  
Long Term Effects ◽  
Symptom Dimensions ◽  
Increased Risk ◽  
The Impact ◽  
The Brain

AbstractAcute exposure to cannabis has been associated with an array of cognitive alterations, increased risk for neuropsychiatric illness, and other neuropsychiatric sequelae including the emergence of acute psychotic symptoms. However, the brain alterations associating cannabis use and these behavioral and clinical phenotypes remains disputed. To this end, neuroimaging can be a powerful technique to non-invasively study the impact of cannabis exposure on brain structure and function in both humans and animal models. While chronic exposure studies provide insight into how use may be related to long-term outcomes, acute exposure may reveal interesting information regarding the immediate impact of use and abuse on brain circuits. Understanding these alterations could reveal the connection with symptom dimensions in neuropsychiatric disorders and, more specifically with psychosis. The purpose of the present review is to: 1) provide an update on the findings of pharmacological neuroimaging studies examining the effects of administered cannabinoids and 2) focus the discussion on studies that examine the sensitive window for the emergence of psychosis. Current literature indicates that cannabis exposure has varied effects on the brain, with the principal compounds in cannabis (delta-9-tetrahydrocannabinol and cannabidiol) altering activity across different brain regions. Importantly, we also discovered critical gaps in the literature, particularly regarding sex-dependent responses and long-term effects of chronic exposure. Certain networks often characterized as dysregulated in psychosis, like the default mode network and limbic system, were also impacted by THC exposure, identifying areas of particular interest for future work investigating the potential relationship between the two.

Challenges of Research in an Active Conflict Environment

2020 ◽  
pp. 113-126
Author(s):  
Boukary Sangaré ◽  
Jaimie Bleck
Keyword(s):  
High Risk ◽  
Armed Conflict ◽  
Risk Assessments ◽  
Security Assessment ◽  
Long Term Effects ◽  
Local Networks ◽  
Specific Safety ◽  
Conducting Research ◽  
Context Specific

This chapter highlights context-specific safety protocols and procedures of research in a highly violent context. It mentions the experience of Boukary Sangaré and Jaimie Bleck on conducting research in Central and Northern Mali across the lines of North–South collaboration. It discusses strategies of fieldwork in areas of armed conflict where the state of Mali has almost disappeared. The chapter recommends closed collaborations between foreign and local researchers to show that safety in high-risk contexts is dependent on up-to-date information from local networks that is continuously fed into the security assessment. It also cautions that risk assessments always have to consider the long-term effects of research as violent situations can be highly volatile, making what was safe yesterday potentially dangerous tomorrow.

scholarly journals Using Laboratory, Mesocosm, and Field Data In Ecological Risk Assessments for Nearshore Dispersant Use

1999 ◽  
Vol 1999 (1) ◽  
pp. 1023-1026
Author(s):  
Don Aurand ◽  
Gina Coelho
Keyword(s):  
Water Column ◽  
Ecological Risk ◽  
Field Data ◽  
The United States ◽  
Risk Assessments ◽  
Historical Records ◽  
Response Process ◽  
Trade Off ◽  
Oil Spill Response ◽  
Ecological Risk Assessments

ABSTRACT In the United States, pre-approval for dispersant use exists only in conservatively defined circumstances of water depth and/or distance off shore. Historical records suggest that most opportunities for dispersant use will occur closer to shore and in shallower water than defined in existing pre-approval areas. The issue is to determine when it is appropriate to relax these standards in order to protect sensitive nearshore habitats, despite the potential for increased ecological effects in the water column. This paper reviews selected data in the context of Ecological Risk Assessment (ERA) protocols. In some cases onshore impacts are clearly decreased by dispersant use without adversely affecting the water column. This is especially true for small- or moderate-sized spills, often not viewed as a high priority for dispersant use. In other cases, however, trade-off decisions must be made, and when the ERA approach is properly integrated into oil spill response process, it can improve the likelihood of proper use of dispersants, and assist in the identification of appropriate dispersant response capabilities.

scholarly journals Better Overeducated than Unemployed? The Short- and Long-Term Effects of an Overeducated Labour Market Re-entry

2015 ◽  
Vol 32 (2) ◽  
pp. 251-265 ◽  
Author(s):  
Jonas Voßemer ◽  
Bettina Schuck
Keyword(s):  
Continuing Education ◽  
Job Quality ◽  
Long Term Effects ◽  
Trade Off ◽  
Stepping Stone ◽  
Short And Long Term ◽  
Lock In ◽  
The Unemployed ◽  
And Training

Abstract Previous studies have shown that overeducation is inferior to adequate employment. For example, overeducated workers have lower earnings, participate less often in continuing education and training, and are less satisfied with their jobs. This article changes perspectives by asking whether it is better for the unemployed to take up a job for which they are overeducated or to remain unemployed and continue the search for adequate employment. Theoretically, we rely on the established confrontation of the stepping-stone and trap hypotheses, which make opposing predictions in terms of long-term employment chances and job quality. Using the German Socio-Economic Panel (1984–2012) and applying a dynamic propensity score matching approach, the analyses reveal an interesting trade-off. Although an overeducated re-entry increases the long-term employment chances persistently, it also implies strong lock-in effects into overeducation for up to 5 years after re-employment. In sum, the results support the stepping-stone hypothesis in terms of future employment chances, but also highlight non-negligible risks of remaining trapped in a job that is below one’s level of educational qualification.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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