Exposure Trials Research Articles

Disease on trial: Medical risk and molecular responsibility in HIV exposure and disclosure jury trials (1994–2015)

More than 30 years have passed since the first HIV-specific criminal laws were enacted, generally making it a crime for people living with HIV to have sex with another person without disclosing their HIV-status. This study examines the tensions between medicine and criminal justice discourses in the application of laws governing a once terminal disease that medicine has transformed, over the past three decades, into a manageable condition. Has medical progress affected courtroom discussion? To answer this question, the authors analyze court transcripts from nine criminal HIV nondisclosure jury trials between 1994 and 2015 in Michigan, Tennessee, and Missouri. The analysis focuses on how shifting medical discourses of risk influence the way prosecutors and counsels construct notions of individual responsibility and, thus, culpability for HIV exposure. The authors argue that antiretroviral therapy and sophisticated clinical testing technologies have led to increasingly medicalized notions of criminal responsibility that they term ‘molecular responsibility.’ Over time, arguments over the defendant’s responsibility shift from the realm of morality to incorporate the defendant’s capacity and willingness to medically control the microbiological dimension of their condition.

Efficacy of Prolonged Exposure Therapy, Sertraline Hydrochloride, and Their Combination Among Combat Veterans With Posttraumatic Stress Disorder

ImportanceMeta-analyses of treatments for posttraumatic stress disorder (PTSD) suggest that trauma-focused psychotherapies produce greater benefits than antidepressant medications alone.ObjectiveTo determine the relative efficacy of prolonged exposure therapy plus placebo, prolonged exposure therapy plus sertraline hydrochloride, and sertraline plus enhanced medication management in the treatment of PTSD.Design, Setting, and ParticipantsThe Prolonged Exposure and Sertraline Trial was a randomized, multisite, 24-week clinical trial conducted at the Veterans Affairs Ann Arbor Healthcare System, Veterans Affairs San Diego Healthcare System, Ralph H. Johnson Veterans Affairs Medical Center, and Massachusetts General Hospital Home Base Veterans Program between January 26, 2012, and May 9, 2016. Participants and clinicians were blinded to pill condition, and outcome evaluators were blinded to assignment. Participants completed assessments at weeks 0 (intake), 6, 12, 24, and 52 (follow-up). Participants (N = 223) were service members or veterans of the Iraq and/or Afghanistan wars with combat-related PTSD and significant impairment (Clinician-Administered PTSD Scale score, ≥50) of at least 3 months’ duration. Analyses were on an intent-to-treat basis.InterventionParticipants completed up to thirteen 90-minute sessions of prolonged exposure therapy by week 24. Sertraline dosage was titrated during a 10-week period and continued until week 24; medication management was manualized.Main Outcomes and MeasuresThe primary outcome was symptom severity of PTSD in the past month as assessed by the Clinician-Administered PTSD Scale score at week 24.ResultsOf 223 randomized participants, 149 completed the study at 24 weeks, and 207 (180 men and 27 women; mean [SD] age, 34.5 [8.3 years]) were included in the intent-to-treat analysis. Modified intent-to-treat analysis using a mixed model of repeated measures showed that PTSD symptoms decreased significantly during the 24 weeks (sertraline plus enhanced medication management, 33.8 points; prolonged exposure therapy plus sertraline, 32.7 points; and prolonged exposure therapy plus placebo, 29.4 points; β,–9.39; 95% CI, −11.62 to −7.16; P < .001); however, slopes did not differ by treatment group (prolonged exposure therapy plus placebo group, –9.39; sertraline plus enhanced medication management group, –10.37; and prolonged exposure therapy plus sertraline group, –9.99; P = .81).Conclusions and RelevanceNo difference in change in PTSD symptoms or symptom severity at 24 weeks was found between sertraline plus enhanced medication management, prolonged exposure therapy plus placebo, and prolonged exposure therapy plus sertraline.Trial RegistrationClinicalTrials.gov Identifier: NCT01524133

Utilizing Recirculating Aquaculture Systems to Evaluate the Impact of Oil Toxicity on Marine Fishes: Design and Operation of a Large-Scale Experimental System

AbstractThe long-term damage of oil spills and recovery efforts on wild fishery populations are not well understood. In order to assess potential biological effects of dispersed oil exposure on Gulf of Mexico fishery populations, C-IMAGE (Center for Integrating Modeling and Analysis of the Gulf Ecosystem) scientists examined the sublethal impacts resulting from the 2010 Deepwater Horizon oil spill through a combination of field collections and controlled laboratory exposure experiments. Mote Marine Laboratory scientists and Complete Water Services, LLC (Marietta, GA), engineers partnered to design, develop, and operate a large-scale, zero-discharge, experimental oil contaminant exposure system at Mote Aquaculture Research Park in Sarasota, Florida. This exposure system is linked to a recirculating aquaculture system (RAS) designed to maintain water quality and water chemistry within acceptable parameters and to remove oil and dispersant from system water during the filtration process. Equipment was sourced to ensure that potential oil co-contaminants were not retained within the system. Water quality (oxygen, pH, salinity, temperature) and chemistry (ammonia, nitrite, nitrate, and alkalinity) parameters were monitored and controlled to maintain appropriate environmental conditions for marine fish during experimental trials. The concentrations of petroleum components throughout the system during exposure trials were monitored to ensure that the system was meeting the design parameters. Experimental trials were conducted using the exposure system with three important Gulf of Mexico marine fishes, Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), and Southern flounder (Paralichthys lethostigma). These trials examined the impacts of dispersed oil exposure on facets of fish health including gene expression, transcriptome, immune function, DNA damage, shifts in the microbiome, reproductive potential and success, and the F1 generation from exposed parents. The system was operated successfully through the trials and allowed us to maintain consistent and appropriate water quality conditions in the experimental tanks. The recirculating filtration system successfully maintained water chemistry and removed oil contaminants during the fish exposure trials. The application of the system technology applied in this study has broader applications than the study of hydrocarbon impacts and opens the door for investigation of a wide range of different contaminants.

Treatment for Anxiety and Depression via Clinical Videoconferencing: Evidence Base and Barriers to Expanded Access in Practice.

This review summarizes six decades of clinical outcome research relevant to evidence-based practices for depression and anxiety delivered via clinical videoconferencing. The authors conducted a literature search of previous systematic reviews and an updated search of publications specific to anxiety and depression. Overall, strong evidence supports the safety and clinical effectiveness of administering evidence-based psychotherapy for anxiety and depression via clinical videoconferencing among heterogeneous populations and age ranges, and in multiple care settings, with similar outcomes to in-person care. Despite the overall clinical effectiveness of the modality, the authors discuss common logistical and institutional barriers to long-term effective implementation. Future systems-level research is required to investigate replicable and sustainable models for implementing and expanding access to evidence-based psychotherapies via clinical videoconferencing.

Cellular fatty acid level regulates the effect of tolylfluanid on mitochondrial dysfunction and insulin sensitivity in C2C12 skeletal myotubes

Previous research suggests that the endocrine disrupting chemical tolylfluanid (TF) may promote metabolic dysfunction and insulin resistance in humans. The potential impact of TF on skeletal muscle metabolism has yet to be fully investigated. The purpose of this study was to determine whether TF can promote insulin resistance and metabolic dysfunction in mammalian skeletal muscle cells. C2C12 murine skeletal myotubes were exposed to 1 ppm TF for 24 h. To examine the potential effect of cellular fatty acid levels on TF-dependent regulation of mitochondrial metabolism and insulin signaling, we treated skeletal myotubes with 0.25 mM or 1.0 mM oleic acid (OA) during TF exposure trials. Tolylfluanid (1–10 ppm) reduced lipid accumulation by approximately 20% in 0.25 and 1.0 mM OA treated cells. The addition of 0.25 mM OA completely inhibited the TF-dependent reduction in maximal mitochondrial oxygen consumption rate (OCR) while 1.0 mM OA exacerbated the TF-dependent reduction in mitochondrial OCR. Exposing skeletal myotubes to 1 ppm TF promoted an 80% reduction in mitochondrial membrane potential, which was completely inhibited by 0.25 mM OA and partially inhibited by1.0 mM OA. The addition of 0.25 mM OA promoted a TF-dependent increase in insulin-dependent P-Akt (Ser473). In contrast, the addition of 1.0 mM OA promoted a significant reduction in insulin-dependent P-Akt (Ser473). Further, the addition of 1 ppm TF significantly reduced insulin-dependent mTORC1 activity regardless of OA concentration. Finally, TF significantly reduced insulin-dependent protein synthesis in the 1 mM OA treated cells only. Our results demonstrate that the effect of 1 ppm TF on mitochondrial function and insulin-dependent protein synthesis in skeletal myotubes was largely dependent upon cellular fatty acid levels.

Effects on brain-derived neurotrophic factor signalling of chronic mild stress, chronic risperidone and acute intracranial dopamine receptor challenges.

We have previously reported the effects of intracranial injections of dopamine D1, D2 and D3 ligands in animals subjected to the Novel Object Recognition (NOR) test following exposure to chronic mild stress (CMS) and chronic treatment with risperidone (RSP). Here, we present some molecular biological data from the same animals. It was predicted that brain-derived neurotrophic factor (BDNF) signalling in the prefrontal cortex (PFC) would reflect behavioural performance, implying an increase following acute administration of a D2 agonist or a D3 antagonist, blockade of this effect by CMS and its restoration by chronic RSP. In separate cohorts, animals were injected within the PFC or the hippocampus (HPC) with either the D1 agonist SKF-81297, the D2 agonist quinpirole or the D3 antagonist SB-277,011, following exposure to control conditions or CMS and chronic treatment with saline or RSP. Intracranial injections followed an exposure trial in the NOR test, with a retention trial 24 h later. Immediately afterwards, the animals were killed and expression of BDNF and TRKβ protein, and their respective mRNAs, was measured in PFC and HPC samples. CMS decreased the expression of TRKβ in both PFC and HPC. Several effects associated with intracranial injection were noted, but they were inconsistent and unrelated to CMS exposure. The effects of CMS on TRKβ are consistent with a decrease in BDNF signalling, albeit that expression of BDNF itself did not change significantly. There was no evidence for an involvement of the BDNF-TRKβ system in responses to RSP or dopamine ligands in animals exposed to CMS. However, there was a 24 h delay between the intracranial injection and tissue harvesting, meaning that brief early drug effects could have been missed.

Trait Persistence Moderates the Association between Gender and Change in Smoking Urge Across Repeated Cue Exposure Trials

Previous research suggests that persistence, an individual difference characteristic representing the ability and willingness to maintain engagement in challenging or aversive contexts, may relate to smoking relapse. Improving understanding of the persistence-relapse risk association could guide improvements in behavioural interventions. We explored whether persistence and gender related to change in smoking urges across multiple cue exposure trials (an analogue of extinction learning and relapse risk). Participants included abstinent smokers who completed 12 massed, 5-minute smoking cue exposure trials using guided imagery as well as olfactory, tactile, visual and motor cues associated with smoking. We used multilevel logistic growth curve modelling to explore predictor associations with change in urge. Results suggested that gender related to urge whereby males showed greater initial and sustained reactivity than females. Persistence was not associated with female urge trajectories. However, compared to males with high persistence, males with low persistence evidenced sustained urge reactivity over time. Results suggest that greater persistence relates to reduction of conditioned responding (e.g., urges) among abstinent male smokers when exposure trials include complex cues most closely related to nicotine self-administration. Because persistence is modifiable, males with low persistence may benefit from interventions that include elements designed to increase persistence in urge eliciting situations.

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri.

The killifish Nothobranchius furzeri is an emerging model organism in the field of ecotoxicology and its applicability in acute and chronic ecotoxicity testing has been demonstrated. Overall, the sensitivity of the species to toxic compounds is in the range with, or higher than, that of other model species. This work describes protocols for acute, chronic, and multigenerational bioassays of single and combined stressor effects on N. furzeri. Due to its short maturation time and life-cycle, this vertebrate model allows the study of endpoints such as maturation time and fecundity within four months. Transgenerational full life-cycle exposure trials can be performed in as little as 8 months. Since this species produces eggs that are drought-resistant and remain viable for years, the on-site culture of the species is not needed but individuals can be recruited when required. The protocols are designed to measure life-history traits (mortality, growth, fecundity, weight) and critical thermal maximum.

Passivation of Plasmonic Colors on Bulk Silver by Atomic Layer Deposition of Aluminum Oxide.

We report the passivation of angle-independent plasmonic colors on bulk silver by atomic layer deposition (ALD) of thin films of aluminum oxide. The colors are rendered by silver nanoparticles produced by laser ablation and redeposition on silver. We then apply a two-step approach to aluminum oxide conformal film formation via ALD. In the first step, a low-density film is deposited at low temperature to preserve and pin the silver nanoparticles. In the second step, a second denser film is deposited at a higher temperature to provide tarnish protection. This approach successfully protects the silver and plasmonic colors against tarnishing, humidity, and temperature, as demonstrated by aggressive exposure trials. The processing time associated with deposition of the conformal passivation layers meets industry requirements, and the approach is compatible with mass manufacturing.

The continuous vs discontinuous use of restorative safety behaviors on symptoms of contamination fear: An experimental investigation

Background and objectivesCognitive-behavioral theorists posit that safety behaviors (SBs) interfere with important exposure processes and should be removed from therapy. However, there is growing evidence to suggest that restorative SBs (RSB; those that allow for full confrontation with a core threat) do not adversely affect exposure outcomes, and their implementation during exposure should be further examined. MethodsThe current study evaluated exposure with the continuous use of RSB (E + CONT) versus discontinuation of RSB (E + DISC), in comparison to exposure with no RSB (ERP). Sixty-seven nonclinical participants completed 15 trials of exposure in which they touched a potentially contaminated stimulus with or without RSB. Behavioral approach tasks were completed at pretreatment, post-treatment, and two-week follow-up to examine changes in subjective distress and degree of behavioral approach. ResultsThe three conditions were not different on clinical symptoms and behavioral approach at post-treatment and follow-up, indicating that the hypothesized superiority effect of E + DISC was not supported. However, ratings obtained during repeated exposure trials indicated that E + DISC evidenced greater symptom reduction following the removal of RSB. LimitationsThe use of a healthy undergraduate sample and standardization of the exposure procedure. ConclusionsAlthough findings were contrary to hypotheses, these data provide added support for the benign role of RSB as compared to conventional exposure. Furthermore, the removal of RSB may lead to more favorable process outcomes during exposure. The theoretical and clinical implications of these findings are discussed, and future directions are provided.

Effect of pre-milking teat disinfection on clinical mastitis incidence in a dairy herd in Northern Queensland, Australia.

To determine if a pre-milking teat disinfection protocol would reduce the incidence of clinical mastitis by greater than 50%. Two pre-milking routines were compared in a natural exposure trial. Cows from a single dairy herd were randomly assigned to control (n = 246) and experimental (pre-milking teat disinfection [PMTD]; n = 244) groups. For cows in the control group, the pre-milking routine involved minimal teat-washing, except for cows with wet teat contamination. For cows in the PMTD group, the pre-milking routine involved washing of all teats, dipping with a commercial 0.1% available iodine solution, allowing a minimum of 30 s contact time and then drying of the teats using disposable paper towel. Clinical cases encountered during the trial were recorded and pathogens were isolated from milk samples using standard laboratory methods. The effect of PMTD was determined using multivariable binary logistic regression. Multiparous animals in the PMTD group had higher odds of experiencing clinical mastitis overall and of experiencing clinical mastitis caused by environmental pathogens (odds ratio (OR) 1.97 and 4.11, 95% confidence interval (CI) 1.15-3.38 and 1.49-11.3, respectively). In primiparous animals, pre-milking teat disinfection did not reduce the odds of clinical mastitis by greater than 50% (OR 1.31, 95%CI 0.52-3.29). In this herd, PMTD increased the odds of clinical mastitis. The effectiveness of PMTD to prevent clinical mastitis in pasture-based systems is likely to vary greatly between herds. We therefore recommend against the wholesale use of this practice on Australian farms.

IEI-EMF provocation case studies: A novel approach to testing sensitive individuals.

The etiology of Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is controversial. While the majority of studies have indicated that there is no relationship between EMF exposure and symptoms reported by IEI-EMF sufferers, concerns about methodological issues have been raised. Addressing these concerns, the present experiment was designed as a series of individual case studies to determine whether there is a relationship between radiofrequency-electromagnetic field (RF-EMF) exposure and an IEI-EMF individual's self-reported symptoms. Three participants aged 44-64 were tested during a series of sham and active exposure trials (2 open-label trials; 12 randomized, double-blind, counterbalanced trials), where symptom severity and exposure detection were scored using 100 mm visual analogue scales. The RF-EMF exposure was a 902-928 MHz spread spectrum digitally modulated signal with an average radiated power output of 1 W (0.3 W/m2 incident power density at the participant). In the double-blind trials, no significant difference in symptom severity or exposure detection was found for any of the participants between the two conditions. Belief of exposure strongly predicted symptom severity score for all participants. Despite accounting for several possible limitations, the present experiment failed to show a relationship between RF-EMF exposure and an IEI-EMF individual's symptoms. Bioelectromagnetics. 39:132-143, 2018. © 2017 Wiley Periodicals, Inc.

Glyphosate has limited short-term effects on commensal bacterial community composition in the gut environment due to sufficient aromatic amino acid levels.

Recently, concerns have been raised that residues of glyphosate-based herbicides may interfere with the homeostasis of the intestinal bacterial community and thereby affect the health of humans or animals. The biochemical pathway for aromatic amino acid synthesis (Shikimate pathway), which is specifically inhibited by glyphosate, is shared by plants and numerous bacterial species. Several invitro studies have shown that various groups of intestinal bacteria may be differently affected by glyphosate. Here, we present results from an animal exposure trial combining deep 16S rRNA gene sequencing of the bacterial community with liquid chromatography mass spectrometry (LC-MS) based metabolic profiling of aromatic amino acids and their downstream metabolites. We found that glyphosate as well as the commercial formulation Glyfonova®450 PLUS administered at up to fifty times the established European Acceptable Daily Intake (ADI=0.5mg/kg body weight) had very limited effects on bacterial community composition in Sprague Dawley rats during a two-week exposure trial. The effect of glyphosate on prototrophic bacterial growth was highly dependent on the availability of aromatic amino acids, suggesting that the observed limited effect on bacterial composition was due to the presence of sufficient amounts of aromatic amino acids in the intestinal environment. A strong correlation was observed between intestinal concentrations of glyphosate and intestinal pH, which may partly be explained by an observed reduction in acetic acid produced by the gut bacteria. We conclude that sufficient intestinal levels of aromatic amino acids provided by the dietalleviates the need for bacterial synthesis of aromatic amino acids and thus prevents an antimicrobial effect of glyphosate invivo. It is however possible that the situation is different in cases of human malnutrition or in production animals.

Integrating biological treatment mechanisms into randomized clinical trials: Design of PROGrESS (PROlonGed ExpoSure and Sertraline Trial)

Increased emphasis on mechanisms of treatment effectiveness, biomarker predictors, and objective indicators of treatment response has sparked interest in integrated, translational treatment outcomes trials. The PROlonGed ExpoSure and Sertraline Trial (PROGrESS) is one such randomized controlled trial (RCT) focused on a key question in clinical management of posttraumatic stress disorder (PTSD) - the comparative and combined effectiveness of medication and psychotherapy. PROGrESS employs a state of the art trial design to examine psychotherapy and medication effects across three conditions: 1) Prolonged Exposure (PE) plus pill placebo, 2) Sertraline (SERT) plus Enhanced Medication Management (EMM), and 3) Combined treatment (PE/SERT). Innovative measures will capture potential biomarker predictors and indicators of treatment response within and across these three treatment conditions in Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) service members and veterans with PTSD. Assessments include clinician-rated measures, self-report outcome measures, saliva for salivary cortisol and cortisol response to awakening at six assessment points, blood at baseline and week 24 for genetic and genomic analysis, as well as resting state connectivity and emotion processing and regulation using functional Magnetic Resonance Imaging (fMRI) paradigms in a subsample of veterans. Accordingly, the current study is designed to provide pragmatic clinical direction for the delivery of PTSD treatment through its primary outcomes in an effectiveness design, and will also provide informative results to elucidate underlying mechanisms and biomarkers involved in PTSD treatment response.

Efficiency and durability of a self-cleaning coating on concrete and stones under both natural and artificial ageing trials

Abstract This study aimed to test the performance under long-term working conditions of a commercial self-cleaning coating, a water-based TiO 2 sol, on three building materials important in recent and older European heritage; Portland limestone, Woodkirk sandstone and concrete. First, the compatibility of the coating (effect on petrophysical properties) with the substrates was demonstrated by examining aesthetic properties and water vapour permeability of the building materials and secondly, the self-cleaning ability of the TiO 2 nanoparticles in degrading artificial stain (rhodamine B) under UV light was evaluated. Finally, the durability (lasting performance) of photocatalytic activity was assessed during one year of outdoor exposure trial and 2000 h of accelerated ageing in a chamber with UV radiation and condensation cycles. Results showed that photocatalytic activity was unaltered on concrete, whereas on sandstone, particularly after artificial ageing, it was reduced due to the removal of nanoparticles from the surface. On limestone, a decrease of TiO 2 content was observed but photodegradation efficiency (ability to perform as self-cleaner) seemed not to be affected.

Evaluating the Effects of Open Shelters on Limestone Deterioration at Archaeological Sites in Different Climatic Locations

ABSTRACTOpen shelters have been proposed as suitable preservation strategies for a variety of heritage sites. However, no concerted attempt has yet been made to analyze their performance in a range of climatic conditions. This study aims to quantify limestone deterioration outside and inside the shelters at two archaeological sites, Hagar Qim (Malta) and the Bishop’s Palace (England), to obtain information on their impact. A simple methodology based on exposure trials and non-destructive tests was used. Globigerina limestone blocks were exposed at both sites from July 2013 to July 2014. Changes in appearance, weight, hardness, color, and moisture content of the blocks in addition to temperature and the likelihood of NaCl crystallization and freeze-thaw events were assessed over the year. This research shows that while deterioration rate is reduced as microclimatic conditions are moderated, open shelters do not completely prevent limestone deterioration at either site, especially in relation to salt weathering.

Minimum lethal concentration of sodium hypochlorite for the amphibian pathogen Batrachochytrium dendrobatidis.

Sodium hypochlorite (NaOCl) is the active ingredient in household bleach and is commonly used as a disinfectant to clean equipment contaminated by the amphibian pathogen Batrachochytrium dendrobatidis (Bd) in lab husbandry and field studies. We conducted a series of replicated exposure trials using a single Global Pandemic Lineage Bd isolate from Panama (JEL 310) and concentrations of NaOCl ranging from 0.006% to 0.6% for exposure times ranging from 30 seconds to 15 minutes to determine the minimum lethal concentration of NaOCl for this isolate of Bd. Sodium hypochlorite completely killed Bd at a concentration of 0.03% during a 15-minute exposure time, while 0.12% NaOCl was effective at all exposure times (30s-15min).

Histopathological changes in the gonads, liver, and kidney of Glossogobius giuris exposed to sub-lethal concentration of diazinon

The organophosphorus insecticide, diazinon that is widely used in agricultural field and private industrial premises to control pests, easily accumulates in aquatic ecosystems and exerts toxic effects on aquatic animals. The study aimed to evaluate the acute toxicity (LC50) of diazinon on Glossogobius giuris and histopathological alterations of its gonads, liver and kidney due to the effect of this insecticide. G. giuris were exposed to different concentrations of diazinon ranging from 0.00025 ppm to 2.048 ppm with parallel untreated control. At the doses of 0.0005 ppm, 0.001 ppm, 0.002 ppm, and 0.004 ppm 40%, 50%, 70%, and 90% mortality of G. giuris were observed within 96 hrs, respectively, whereas, 100% mortality was observed at doses above 0.008 ppm. Based on probit analysis, the LC50 value of diazinon for 96 hrs of exposure on G. giuris was found as 0.001 ppm. During the exposure trial several behavioral alterations including restlessness, sudden and quick movements, loss of equilibrium, increased opercular activities and paralysis were observed in the fish. The histopathological changes observed in the tissues of G. giuris indicate that sub lethal concentration as well as higher concentration caused moderate to severe alterations in the liver, kidney as well as gonads. Kidney was found to be the most seriously affected organ compared to gonads and liver. Major histopathological changes like fragmentation of testis and ovary with ruptured wall, karyolysis, hypertrophy, pyknosis and degenerative changes such as necrosis of tubular and haematopoietic cells of kidney, necrotic hepatocytes, pyknosis, hypertrophy, haemorrhage and vacuolation were observed in the liver cells. The present study demonstrated that diazinon is highly toxic especially to G. giuris and thus, indiscriminate use of this insecticide in the agriculture and industrial sectors should be strictly controlled.Progressive Agriculture 27 (4): 530-538, 2016

Efficacy of a high free iodine barrier teat disinfectant for the prevention of naturally occurring new intramammary infections and clinical mastitis in dairy cows

Using a natural exposure trial design, the goal of our study was to evaluate the clinical efficacy of an iodine teat disinfectant with barrier properties and a high level of free iodine relative to a conventional iodine teat disinfectant with no barrier properties and low levels of free iodine. During the 18 wk of the trial, quarter milk samples were collected every 2 wk from 385 dairy cows from 2 herds. Cows on both farms were assigned in a balanced way according to milk yield, number of lactation, days in milk, somatic cell count (SCC) and microbiology culture pretrial into one of following groups: nonbarrier post milking teat disinfectant (NBAR; n = 195 cows; 747 quarters) or barrier postmilking teat disinfectant (BAR; n = 190 cows; 728 quarters). Afterward, at each scoring date every 2 wk, milk SCC was quantified in samples from all mammary quarters and microbiologic culture was only performed on milk samples with SCC >200,000 cells/mL for multiparous cows and SCC >100,000 cells/mL for primiparous cows. A new intramammary infection (NIMI) was defined when a quarter had milk SCC <200,000 cells/mL for multiparous cows and <100,000 cells/mL for primiparous without microorganism isolation, and in a subsequent sampling visit had milk SCC >200,000 cells/mL for multiparous cows and >100,000 cells/mL for primiparous cows, and positive microorganism isolation. A quarter could have several NIMI, but only 1 case per specific pathogen was considered. The most frequently isolated microorganism group on both farms was Streptococcus spp. (6.25% of total mammary quarters), followed by coagulase-negative staphylococci (3.6%) and Corynebacterium spp. (1.5%). In the present study, an interaction occurred between treatment and week of trial on the incidence risk of NIMI. Quarters disinfected with BAR had 54 and 37% lower odds of NIMI than quarters disinfected with NBAR at 8 and 16 wk of the trial, respectively; whereas at other weeks of the study both products had similar incidence risks of NIMI. Overall, teats disinfected with BAR had 46% lower odds of acquiring a clinical mastitis than those disinfected with NBAR. We concluded that the postmilking teat disinfectant with barrier properties and higher free iodine content reduced the risk of clinical mastitis, although differences in new infections were detected at only weekly time points.

Escaping aversive exposure

This research examined human defensive reactivity when exposure to an aversive event could be escaped but not entirely avoided. Prolonged visual cues indicated whether exposure to an upcoming aversive (i.e., disgusting) picture could be terminated after onset (escaped) or not, or that a neutral go signal would appear. Acoustically elicited startle reflexes were measured during each cue interval, as were cardiac and skin conductance activity. Early in the cuing interval, startle reflexes were potentiated during both escape and inescapable exposure trials, compared to the simple motor context. Later in the interval, reflexes remained potentiated for both escapable and inescapable trials, with potentiation further enhanced when aversive exposure could not be escaped compared to when exposure could be escaped. Heart rate deceleration in the cuing interval indicated increased vigilance when preparing any (escape or neutral) action, whereas skin conductance responding indicated enhanced sympathetic action mobilization particularly in an escape context. These data suggest that startle reflexes engaged in an escape context reflect both motor-related response inhibition and aversive potentiation, and they indicate that defensive motivation is engaged whenever aversive exposure is guaranteed, regardless of whether it can be escaped or not.