Effects of pulse duration and post-exposure period on the nitrite toxicity to a freshwater amphipod

2009 ◽  
Vol 72 (7) ◽  
pp. 2005-2008 ◽  
Author(s):  
Álvaro Alonso ◽  
Julio A. Camargo
Keyword(s):  
Pulse Duration ◽  
Exposure Period ◽  
Post Exposure ◽  
Nitrite Toxicity

scholarly journals Assessment of the insecticidal activity of oral afoxolaner against Phlebotomus perniciosus in dogs

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 63
Author(s):  
Nadège Perier ◽  
Wilfried Lebon ◽  
Leon Meyer ◽  
Noua Lekouch ◽  
Nesrine Aouiche ◽  
...  
Keyword(s):  
Untreated Control ◽  
Exposure Period ◽  
Blood Feeding ◽  
Treated Group ◽  
Control Group ◽  
Untreated Control Group ◽  
Phlebotomus Perniciosus ◽  
Post Exposure ◽  
Insecticidal Efficacy ◽  
Healthy Dogs

Twelve healthy dogs were included in this laboratory efficacy study. Six dogs were randomly allocated based on body weight to an untreated control group and six to an afoxolaner (NexGard®) treated group. In the treatment group, afoxolaner was administered orally on Day 0 in accordance with label instructions. On Days 1, 14 and 28, each dog was exposed to 60 unfed female and 10 male Phlebotomus perniciosus sandflies for 1 h. At the end of each exposure period, sandflies were counted and assessed for viability and feeding status. There was no statistical difference in mortality (0.0–5.4%), nor in feeding proportion (61.6–78%) between the control and the treated groups at all 1-h post-exposure assessments. After collection, live fed and unfed sandflies were kept for viability assessments at 48 and 72 h post-exposure. In the untreated control group, the average percentages of live, fed, female sandflies after exposure, on Days 1, 14 and 28, ranged from 51% to 74% at 48 h and from 46% to 57% at 72 h, demonstrating model robustness over the 28 days of the study. Significantly fewer live fed sandflies were recorded for the afoxolaner treated group (p < 0.01). The insecticidal efficacy was 100%, 95.9% and 75.2% at 48 h post Days 1, 14 and 28 exposures, respectively, and 100%, 100% and 86.3% at 72 h post Days 1, 14, and 28 exposures, respectively. A single administration of oral afoxolaner (NexGard®) to dogs significantly killed P. perniciosus sandflies 48 and 72 h after blood feeding for 1 month.

Erratum to “Evaluation of neurobehavioral and neuroinflammatory end-points in the post-exposure period in rats sub-acutely exposed to manganese” [Toxicology 314(1) (2013) 95–99]

Toxicology ◽  
2014 ◽  
Vol 316 ◽  
pp. 75
Author(s):  
Santos Dinamene ◽  
Batoreu M. Camila ◽  
I. Tavares de Almeida ◽  
L. Davis Randall ◽  
Mateus M. Luisa ◽  
...  
Keyword(s):  
Exposure Period ◽  
End Points ◽  
Post Exposure

scholarly journals The evaluation of immunoregulatory markers in the course of neurointoxication by mercury over the post-exposure period

2019 ◽  
Vol 95 (12) ◽  
pp. 1138-1141 ◽  
Author(s):  
Galina M. Bodienkova ◽  
V. S. Rukavishnikov ◽  
E. V. Boklazhenko
Keyword(s):  
Exposure Period ◽  
Post Exposure

scholarly journals The Acute and Delayed Mortality of the Northern Krill (Meganyctiphanes norvegica) When Exposed to Hydrogen Peroxide

2020 ◽  
Vol 105 (5) ◽  
pp. 705-710
Author(s):  
Rosa H. Escobar-Lux ◽  
Ole B. Samuelsen
Keyword(s):  
Hydrogen Peroxide ◽  
Marine Ecosystem ◽  
Exposure Period ◽  
Toxicity Tests ◽  
Negative Effects ◽  
Post Exposure ◽  
The North ◽  
Acute Toxicity Tests ◽  
Risk Of Exposure ◽  
Meganyctiphanes Norvegica

Abstract Bath treatment pharmaceuticals used to control sea lice infestations in the salmonid industry, such as hydrogen peroxide (H2O2), are released directly into the environment where non-target organisms are at risk of exposure. The aim of this study was to determine the threshold concentrations for mortality of the Northern krill, Meganyctiphanes norvegica, a major component of the north Atlantic marine ecosystem. To assess the lethal effects of H2O2, we carried out a series of 1 h acute toxicity tests and assessed mortality through a 48 h post-exposure period. One-hour exposure to 170 mg/L, corresponding to 10% of the recommended H2O2 treatment, caused 100% mortality and a subsequent acute median-lethal concentration LC50 value of 32.5 mg/L. Increased mortality was observed with time in all exposed groups, resulting in successively lower LC50 values during the post-exposure period. The suggested H2O2 concentrations have the potential of causing negative effects to the Northern krill.

Abstract 154: Guideline Removal of Atropine and Survival After Adult In-Hospital Cardiac Arrest With Non-Shockable Rhythms

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Mathias J Holmberg ◽  
Ari Moskowitz ◽  
Sebastian Wiberg ◽  
Lise Witten ◽  
Anne V Grossestreuer ◽  
...  
Keyword(s):  
Time Series ◽  
Cardiac Arrest ◽  
Life Support ◽  
Interrupted Time Series ◽  
Exposure Period ◽  
Advanced Cardiac Life Support ◽  
Mean Difference ◽  
Interrupted Time Series Analysis ◽  
Post Exposure ◽  
Hospital Cardiac Arrest

Introduction: Atropine was removed from the 2010 American Heart Association’s Advanced Cardiac Life Support guidelines as routine management of non-shockable cardiac arrest, although the evidence to support or refute the use of atropine is lacking. In a previous study, atropine usage was shown to subsequently decline markedly. Whether removing atropine from the guidelines has affected survival remains unknown. Methods: Using the Get With The Guidelines®-Resuscitation registry, we included adult patients with an index in-hospital cardiac arrest between 2006-2015. Non-shockable and shockable cardiac arrest patients with high vs. low propensity score to receive atropine were separated into two cohorts. An interrupted time-series analysis was used to compare survival before (pre-exposure) and after (post-exposure) introduction of the 2010 guidelines. A difference-in-difference approach was used to compare the interrupted time-series results between the non-shockable and shockable cohorts to account for guideline changes unrelated to atropine. Results: We included 21,822 non-shockable and 4,268 shockable cardiac arrests. Patient characteristics were similar between the pre-exposure and post-exposure period. Atropine was used for 9,170 (86%) non-shockable and 733 (34%) shockable cardiac arrests in the pre-exposure period and 3,903 (35%) non-shockable and 339 (16%) shockable cardiac arrests in the post-exposure period. The change over time in survival from the pre-exposure to the post-exposure period was not significantly different for the non-shockable compared to the shockable cohort (mean difference: 2.0% [95%CI: -0.7, 4.6] per year, p = 0.15, Figure). The immediate change in survival after introducing the guidelines was also not different between the cohorts (mean difference: 3.9% [95%CI: -2.2, 10], p = 0.21, Figure). Conclusions: The removal of atropine from the 2010 guidelines was not associated with a change in survival in our analysis.

Radiofrequency radiation (900 MHz)-induced DNA damage and cell cycle arrest in testicular germ cells in swiss albino mice

2016 ◽  
Vol 33 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Neelam Pandey ◽  
Sarbani Giri ◽  
Samrat Das ◽  
Puja Upadhaya
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Germ Cell ◽  
Germ Cells ◽  
Sperm Count ◽  
Exposure Period ◽  
Swiss Albino Mice ◽  
Radiofrequency Radiation ◽  
Post Exposure ◽  
Albino Mice

Even though there are contradictory reports regarding the cellular and molecular changes induced by mobile phone emitted radiofrequency radiation (RFR), the possibility of any biological effect cannot be ruled out. In view of a widespread and extensive use of mobile phones, this study evaluates alterations in male germ cell transformation kinetics following RFR exposure and after recovery. Swiss albino mice were exposed to RFR (900 MHz) for 4 h and 8 h duration per day for 35 days. One group of animals was terminated after the exposure period, while others were kept for an additional 35 days post-exposure. RFR exposure caused depolarization of mitochondrial membranes resulting in destabilized cellular redox homeostasis. Statistically significant increases in the damage index in germ cells and sperm head defects were noted in RFR-exposed animals. Flow cytometric estimation of germ cell subtypes in mice testis revealed 2.5-fold increases in spermatogonial populations with significant decreases in spermatids. Almost fourfold reduction in spermatogonia to spermatid turnover (1C:2C) and three times reduction in primary spermatocyte to spermatid turnover (1C:4C) was found indicating arrest in the premeiotic stage of spermatogenesis, which resulted in loss of post-meiotic germ cells apparent from testis histology and low sperm count in RFR-exposed animals. Histological alterations such as sloughing of immature germ cells into the seminiferous tubule lumen, epithelium depletion and maturation arrest were also observed. However, all these changes showed recovery to varied degrees following the post-exposure period indicating that the adverse effects of RFR on mice germ cells are detrimental but reversible. To conclude, RFR exposure-induced oxidative stress causes DNA damage in germ cells, which alters cell cycle progression leading to low sperm count in mice.

Aftereffects from Virtual Environment Exposure: How Long do They Last?

1998 ◽  
Vol 42 (21) ◽  
pp. 1476-1480 ◽  
Author(s):  
Kay M. Stanney ◽  
Robert S. Kennedy
Keyword(s):  
Virtual Environment ◽  
Well Being ◽  
Exposure Period ◽  
Post Exposure ◽  
Environment Exposure ◽  
Before And After ◽  
Exposure Levels ◽  
Hand Coordination ◽  
Oculomotor Disturbances ◽  
Very High

The duration of the aftereffects from virtual environment (VE) exposure are not well characterized to date. Yet information concerning the incidence and enduring nature of these effects is essential to delimit the effective and safe use of VE technology. This study examined the aftereffects from VE exposure after three different exposure periods ranging from 15 to 45 minutes. Sixty participants were randomly assigned to one of the exposure periods, twenty to each condition. Sickness symptomatology, eye-hand coordination, and postural stability were measured before and after exposure. There were five measurements taken after exposure at 15 minute intervals. The results from the sickness symptomatology have been analyzed to date and show significantly higher symptomatology that persists for the entire post-exposure period in which measurements were taken. One hour after exposure the Total Severity of symptoms were 12 times higher than pre-exposure levels. Examining the three sub-dimensions of these symptoms indicated that one hour after exposure Nausea symptoms were 10x's higher, Oculomotor disturbances were 7x's higher and Disorientation was 95x's higher than pre-exposure levels. The very high levels of reported Disorientation are consistent with other studies that indicate that VE systems engender high levels of dizziness and vertigo upon post-exposure. The tangible and persistent aftereffects raise concerns for the safety and well being of VE system users and suggest that their activities should be monitored upon post exposure.

scholarly journals CHARACTERISTICS OF DISTURBANCES IN NEUROPHYSIOLOGICAL AND PSYCHO-EMOTIONAL STATUS OF PATIENTS WITH VIBRATION DISEASE IN THE POSTEXPOSURE PERIOD

2016 ◽  
Vol 1 (6) ◽  
pp. 98-102
Author(s):  
Лахман ◽  
Oleg Lakhman ◽  
Катаманова ◽  
Elena Katamanova ◽  
Кулешова ◽  
...  
Keyword(s):  
Exposure Period ◽  
Control Group ◽  
Bioelectrical Activity ◽  
Length Of Service ◽  
Local Vibration ◽  
Afferent Pathways ◽  
Post Exposure ◽  
Vibration Disease ◽  
Upper And Lower Extremities ◽  
The Mean

The article presents the results of the studies of the central and peripheral nervous systems, psychoemotional status of patients with vibration disease associated with exposure to the local vibration in the post-exposure period. The stud-ies were performed in patients with vibration disease (n=18) who do not work in the contact with the local vibration at present. The mean age of the patients was 50.7±5.4years, the mean length of service in the contact with local vibration –17.9±2.8years, the mean post-exposure period – 5.2±2.2years. 30male persons having no contact with industrial hazard were comprised the control group. Electroencephalography, electroneuromyography, recording of somatosensory evoked potentials were carried out and patients’ personality peculiarities were studied. The changes of the brain bioelectrical activity, disorders of the autonomic and afferent regulation of the cerebral level, dysfunc-tion in diencephalic structures, disorders of the subcortical and cortical structures of the central afferent pathways; demyelization of the peripheral nerves of the upper and lower extremities were set in patients with vibration disease in the post-exposure period. Psychological studies have shown that patients with vibration disease in the post-exposure period preserve such psychological peculiarities as neuroticism manifested with inner tension, nervousness and chronic feeling of discomfort; depressive tendencies being a sign of the existing distress, and anxious-hypochondriac features in the structure of personality traits. All of the above result in formation of stable uncompensated clinical conditions observed in patients with vibration disease caused by local vibration exposure, even after the termination of harmful production factors.

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