scholarly journals Ultrastructural evidence of a mechanosensory function of scale organs (sensilla) in sea snakes (Hydrophiinae)

2019 ◽  
Vol 6 (4) ◽  
pp. 182022 ◽  
Author(s):  
Jenna M. Crowe-Riddell ◽  
Ruth Williams ◽  
Lucille Chapuis ◽  
Kate L. Sanders
Keyword(s):  
Direct Contact ◽  
Light And Electron Microscopy ◽  
Marine Species ◽  
Mechanical Stimuli ◽  
Indirect Contact ◽  
Future Studies ◽  
Sea Snakes ◽  
Ultrastructural Evidence ◽  
Hydrodynamic Stimuli ◽  
Scale Surface

The evolution of epidermal scales was a major innovation in lepidosaurs, providing a barrier to dehydration and physical stress, while functioning as a sensitive interface for detecting mechanical stimuli in the environment. In snakes, mechanoreception involves tiny scale organs (sensilla) that are concentrated on the surface of the head. The fully marine sea snakes (Hydrophiinae) are closely related to terrestrial hydrophiine snakes but have substantially more protruding (dome-shaped) scale organs that often cover a larger portion of the scale surface. Various divergent selection pressures in the marine environment could account for this morphological variation relating to detection of mechanical stimuli from direct contact with stimuli and/or indirect contact via water motion (i.e. ‘hydrodynamic reception’), or co-option for alternate sensory or non-sensory functions. We addressed these hypotheses using immunohistochemistry, and light and electron microscopy, to describe the cells and nerve connections underlying scale organs in two sea snakes, Aipysurus laevis and Hydrophis stokesii . Our results show ultrastructural features in the cephalic scale organs of both marine species that closely resemble the mechanosensitive Meissner-like corpuscles that underlie terrestrial snake scale organs. We conclude that the scale organs of marine hydrophiines have retained a mechanosensory function, but future studies are needed to examine whether they are sensitive to hydrodynamic stimuli.

Reduce odor and NH3 emission: condensation of the carbonatation vapors

2017 ◽  
pp. 534-537
Author(s):  
Nico Antens ◽  
Jan L.M. Struijs
Keyword(s):  
Direct Contact ◽  
Waste Heat ◽  
Pilot Scale ◽  
Sugar Production ◽  
Two Stage ◽  
Indirect Contact ◽  
Nh3 Emission ◽  
Emission Limits ◽  
Plant Trials ◽  
Contact Condensation

At beet sugar production, vapors from first and second carbonatation contain a significant amount of odor components, NH3 and waste heat, which are normally directly released into the environment. Due to sustainability motivations, obligations regarding odor nuisance and expected stricter regulations regarding NH3 emission limits, Suiker Unie decided to take measures to reduce emission via the carbonatation vapors. During the 2015 beet campaign, pilot scale plant trials have been performed to investigate the effectiveness of indirect contact and direct contact condensation of these vapors. Based on this experimental work a two-stage gas scrubbing concept was designed: in the first stage main goal is condensing the vapors and reuse the heat of condensation to heat up limed juice, while the actual scrubbing takes place in the second scrubber. This two-stage gas scrubbing installation has been built at the Vierverlaten factory and was started up in the 2016 beet campaign. The background, pilot scale trials, concept of design and achieved reductions in odor and NH3 emission at industrial scale are discussed.

scholarly journals Modeling Ebola Virus Transmission Using Ferrets

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Marc-Antoine de La Vega ◽  
Geoff Soule ◽  
Kaylie N. Tran ◽  
Kevin Tierney ◽  
Shihua He ◽  
...  
Keyword(s):  
Animal Model ◽  
Direct Contact ◽  
Ebola Virus ◽  
Infected Animal ◽  
Severe Disease ◽  
Virus Transmission ◽  
Metal Mesh ◽  
Indirect Contact ◽  
Specific Antibodies ◽  
Bodily Fluids

ABSTRACT Ebola virus (EBOV) has been responsible for sporadic outbreaks in Central Africa since 1976 and has the potential of causing social disruption and public panic as illustrated by the 2013–2016 epidemic in West Africa. Transmission of EBOV has been described to occur via contact with infected bodily fluids, supported by data indicating that infectious EBOV could be cultured from blood, semen, saliva, urine, and breast milk. Parameters influencing transmission of EBOV are, however, largely undefined in part due to the lack of an established animal model to study mechanisms of pathogen spread. Here, we investigated EBOV transmissibility in male and female ferrets. After intranasal challenge, an infected animal was placed in direct contact with a naive ferret and in contact with another naive ferret (separated from the infected animal by a metal mesh) that served as the indirect-contact animal. All challenged animals, male direct contacts, and one male indirect contact developed disease and died. The remaining animals were not viremic and remained asymptomatic but developed EBOV-glycoprotein IgM and/or IgG specific antibodies—indicative of virus transmission. EBOV transmission via indirect contact was frequently observed in this model but resulted in less-severe disease compared to direct contact. Interestingly, these observations are consistent with the detection of specific antibodies in humans living in areas of EBOV endemicity. IMPORTANCE Our knowledge regarding transmission of EBOV between individuals is vague and is mostly limited to spreading via direct contact with infectious bodily fluids. Studying transmission parameters such as dose and route of infection is nearly impossible in naturally acquired cases—hence the requirement for a laboratory animal model. Here, we show as a proof of concept that ferrets can be used to study EBOV transmission. We also show that transmission in the absence of direct contact is frequent, as all animals with indirect contact with the infected ferrets had detectable antibodies to the virus, and one succumbed to infection. Our report provides a new small-animal model for studying EBOV transmission that does not require adaptation of the virus, providing insight into virus transmission among humans during epidemics.

scholarly journals Two new marine species of Cocconeis (Bacillariophyceae) from the west coast of Sweden

2019 ◽  
Author(s):  
Adil Y. Al-Handal ◽  
Catherine Riaux-Gobin ◽  
Regine Jahn ◽  
Angela Katarina Wulff ◽  
Alison Minerovic
Keyword(s):  
West Coast ◽  
Light And Electron Microscopy ◽  
Marine Species ◽  
Benthic Diatom ◽  
Small Island ◽  
Coastal Regions ◽  
The West ◽  
Two New Species ◽  
Ulva Intestinalis ◽  
Microscopy Examination

This paper is part of a project of studying benthic diatom biodiversity on marine coastal regions of Sweden with focus on rare and less known species. Two new species of Cocconeis Ehrenb. are described from Vrångö, a small island in the west coast of Sweden. Both species were found as epiphytic on the green alga Ulva intestinalis L. Cocconeis magnoareolata Al-Handal, Riaux-Gob., R.Jahn & A.K.Wulff sp. nov. is a small species not exceeding 9 µm in length and characterized by having large subquadrangular areolae on the sternum valve. Cocconeis vrangoensis Al-Handal & Riaux-Gob. sp. nov. appears similar to some taxa of the ‘Cocconeis scutellum complex’, but differs by its stria density on both valves and variable features of the areola and valvocopula ultrastructure. Detailed descriptions based on light and electron microscopy examination, a comparison with closely related taxa, as well as a description of the habitat of both species are here presented.

Lucretius and the Salty Taste of Sea Air

2021 ◽  
Vol 69 ◽  
pp. 173-217
Author(s):  
Pamela Zinn
Keyword(s):  
Direct Contact ◽  
Water Cycle ◽  
Traditional View ◽  
Sensory Threshold ◽  
De Rerum Natura ◽  
Indirect Contact ◽  
Salty Taste

This article treats the sense of taste in Epicurean thought through the evidence in Lucretius’ De rerum natura. It reconstructs Lucretius’ account of what taste is and how it works, with a view to explaining instances like the taste of salt by the seaside, where we seem to taste at a distance. I argue that such instances are not exceptions, but examples that reveal more about the processes behind them. When analyzed in conjunction with the physiology of taste and the water cycle, the salty taste of sea air confirms the traditional view that the perception of flavor consistently occurs through direct contact with the object of perception, not through indirect contact with an intermediary. Moreover, it advances the understanding of what comes into contact, what the perceiver contributes to taste, and taste’s sensory threshold.

Mechanisms of acute ankle syndesmosis ligament injuries in professional male rugby union players: a systematic visual video analysis

2020 ◽  
pp. bjsports-2020-102281
Author(s):  
Eamonn Delahunt ◽  
Garreth Farrell ◽  
Andrew Boylan ◽  
Fearghal Kerin ◽  
Peter Tierney ◽  
...  
Keyword(s):  
Video Analysis ◽  
Direct Contact ◽  
External Rotation ◽  
Rugby Union ◽  
Qualitative Description ◽  
Ligament Injuries ◽  
Injured Limb ◽  
Indirect Contact ◽  
Injury Mechanisms ◽  
Hip Flexion

BackgroundThe mechanisms of acute ankle syndesmosis ligament injuries in professional rugby union are not well understood.AimTo describe the mechanisms of acute ankle syndesmosis ligament injuries in male professional rugby union players using systematic visual video analysis.MethodsAll time-loss acute ankle syndesmosis ligament injuries identified via retrospective analysis of the Leinster Rugby injury surveillance database across the 2013/2014 to 2017/2018 seasons were considered as potentially eligible for inclusion. Three Chartered Physiotherapists (analysts) independently assessed all videos with a final consensus meeting convened to describe the injury mechanisms. One of the analysts developed a qualitative description of each injury mechanism.ResultsThirteen acute ankle syndesmosis injuries were included in this study. The most common biomechanical presentation of the injured limb was characterised by hip flexion, knee flexion, knee valgus, ankle dorsiflexion, pronation and external rotation of the foot. Six of the included injuries (46%) were the result of an external load application to the injured limb (ie, direct contact injuries). In the other seven instances (54%), the injury was the result of a collapse of the injured player’s body mass over the injured ankle joint, while tackling or being tackled, without direct contact to the injured limb (ie, indirect contact injuries).ConclusionInjuries incurred while tackling were exclusively the result of suboptimal tackle mechanics. A majority of injuries incurred while being tackled involved a posterior tackle, which often resulted in a posterior collapse of the injured player’s centre of mass over a fixed externally rotated foot.

scholarly journals Systematic video analysis of ACL injuries in professional male football (soccer): injury mechanisms, situational patterns and biomechanics study on 134 consecutive cases

2020 ◽  
Vol 54 (23) ◽  
pp. 1423-1432 ◽  
Author(s):  
Francesco Della Villa ◽  
Matthew Buckthorpe ◽  
Alberto Grassi ◽  
Alberto Nabiuzzi ◽  
Filippo Tosarelli ◽  
...  
Keyword(s):  
Video Analysis ◽  
Direct Contact ◽  
Acl Injury ◽  
Injury Pattern ◽  
Biomechanical Analysis ◽  
Knee Valgus ◽  
Mechanical Perturbation ◽  
Indirect Contact ◽  
Acl Injuries ◽  
Injury Mechanisms

BackgroundA few small studies have reported on the mechanisms of ACL injury in professional male football.AimTo describe the mechanisms, situational patterns and biomechanics (kinematics) of ACL injuries in professional male football matches.MethodsWe identified 148 consecutive ACL injuries across 10 seasons of professional Italian football. 134 (90%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 107 cases. Three independent reviewers evaluated each video. ACL injury epidemiology (month), timing within the match and pitch location at the time of injury were also reported.Results59 (44%) injuries were non-contact, 59 (44%) were indirect contact and 16 (12%) were direct contact. Players were frequently perturbed immediately prior to injury. We identified four main situational patterns for players who suffered a non-contact or an indirect contact injury: (1) pressing and tackling (n=55); (2) tackled (n=24); (3) regaining balance after kicking (n=19); and (4) landing from a jump (n=8). Knee valgus loading (n=83, 81%) was the dominant injury pattern across all four of these situational patterns (86%, 86%, 67% and 50%, respectively). 62% of the injuries occurred in the first half of the matches (p<0.01). Injuries peaked at the beginning of the season (September–October) and were also higher at the end of the season (March–May).Conclusions88% of ACL injuries occurred without direct knee contact, but indirect contact injuries were as frequent as non-contact injuries, underlying the importance of mechanical perturbation. The most common situational patterns were pressing, being tackled and kicking.

Contact — but not foul play — dominates injury mechanisms in men’s professional handball: a video match analysis of 580 injuries

2020 ◽  
Vol 54 (16) ◽  
pp. 984-990 ◽  
Author(s):  
Patrick Luig ◽  
Werner Krutsch ◽  
Thomas Henke ◽  
Christian Klein ◽  
Hendrik Bloch ◽  
...  
Keyword(s):  
Direct Contact ◽  
Knee Injuries ◽  
Central Zone ◽  
Ankle Injuries ◽  
Common Mechanism ◽  
Match Analysis ◽  
Severe Injuries ◽  
Indirect Contact ◽  
Injury Mechanisms ◽  
Video Material

AimWe aimed to identify patterns and mechanisms of injury situations in men’s professional handball by means of video match analysis.MethodsModerate and severe injuries (absence of >7 days) sustained in competition in one of six seasons (2010 to 2013 and 2014 to 2017) in men’s professional handball were prospectively analysed with a newly developed standardised observation form. Season 2013 to 2014 was excluded because of missing video material.Results580 injuries were identified: 298 (51.4%) contact injuries, 151 (26.0%) indirect contact injuries and 131 (22.6%) non-contact injuries. Head (87.5%), hand (83.8%), shoulder (70.2%) and ankle (62.9%) injuries were mainly sustained during direct contact. Typical contact injuries included collision with an opponent’s upper extremity or torso, and ankle injuries mainly consisted of foot-to-foot collisions. A large proportion (41.7%) of knee injuries were caused by indirect contact, whereas thigh injuries mainly occurred (56.4%) through non-contact mechanism. Wing (56.9%) and pivot (58.4%) players had the highest proportion of contact injuries, whereas backcourt players had a high proportion of indirect contact injuries (31.5%) and goalkeepers of non-contact injuries (48.9%). The injury proportion of foul play was 28.4%. Most injuries occurred in the central zone between the 6-metre and 9-metre lines (26.1%) and during the last 10 min of each match half (OR 1.71, p=0.016).ConclusionsIn men’s professional handball in a league setting, contact — but not foul play — was the most common mechanism associated with moderate and severe injuries. Head, hand, shoulder and ankle injury were mainly sustained during direct contact.

Effect of direct and indirect contact with mental illness on dangerousness and social distance

2017 ◽  
Vol 64 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Minhwa Lee ◽  
Mikyung Seo
Keyword(s):  
Mental Illness ◽  
Standard Deviation ◽  
Interaction Effect ◽  
Social Distance ◽  
Direct Contact ◽  
Indirect Contact ◽  
Independent Variables ◽  
Main Effect ◽  
Dependent Variables ◽  
Two Independent Variables

Background: This study is based on the contact hypothesis that contact with mental illness is the most effective anti-stigma strategy. Aims: This study aims to analyze which form of contact can most effectively decrease the dangerousness and social distance associated with schizophrenia, depression and alcoholism. Method: In total, 573 Korean adults ( Mage = 43.71 years, standard deviation ( SD) = 13.41; 54.1% male, 45.9% female) were surveyed about randomly assigned vignettes of schizophrenia, depression and alcoholism. The participants were questioned on the dangerousness and social distance associated with the assigned vignette, as well as direct and indirect contact experience with the mental illness. Two-way analysis of variance (ANOVA) was used to determine the main effect and interaction effect that the type of mental illness and contact experience have on the two dependent variables (dangerousness and social distance). Results: The findings show that the type of mental illness has a significant main effect on dangerousness and social distance, but contact type only has a significant main effect on social distance. Moreover, the two independent variables (mental illness subtype and contact experience) have an interaction effect on two dependent variables (dangerousness and social distance). Therefore, the anti-stigma effect of contact varies according to the type of mental illness. Conclusion: Our findings suggest that appropriate anti-stigma strategies are required for each type of mental illness. Considering that opportunities for direct contact with persons with mental illness are highly limited, it is necessary to actively utilize indirect contact.

scholarly journals Sibling Relation, Ethnic Prejudice, Direct and Indirect Contact: There is a Connection?

2015 ◽  
Vol 11 (4) ◽  
pp. 664-676 ◽  
Author(s):  
Sara Alfieri ◽  
Elena Marta
Keyword(s):  
Young People ◽  
Direct Contact ◽  
Ad Hoc ◽  
Indirect Contact ◽  
Ethnic Prejudice ◽  
Mixed Anova

The literature on the socialisation of prejudice has concentrated on “vertical” processes (from parents to children), ignoring siblings’ contribution. This work aims to investigate the effect of contact (direct or indirect) with the outgroup that young people experience a) directly or b) indirectly through older or younger siblings’ friendships. Our hypotheses are a) that young people with friends in the outgroup will report lower prejudice levels (direct contact), as will young people who have older or younger siblings with friends in the outgroup (indirect contact); b) that other forms of contact such as having classmates/coworkers, neighbours, or employees are not effective in reducing either direct or indirect prejudice. 88 sibling dyads were administered the blatant and subtle prejudice questionnaire (Pettigrew & Meertens, 1995) and some ad hoc items aimed at investigating the typology of the contact experienced. The analysis of mixed ANOVA reveals that the first hypothesis was partially confirmed in that prejudice (subtle for the younger sibling and blatant for the older one) decreases in a statistically significant way only when there is the co-presence of direct and indirect contact. The second hypothesis is fully confirmed as no statistically significant differences emerged between the groups.

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