Double-countershading as a means of camouflage in larvae of Orange-tip Anthocharis cardamines (Linnaeus, 1758) (Lepidoptera: Pieridae)

2021 ◽  
Vol 72 (3) ◽  
pp. 199-202
Author(s):  
Clive Craik
Keyword(s):  
Surface Effect ◽  
Food Plant ◽  
Defence Mechanisms ◽  
Bird Predation ◽  
Plant Availability ◽  
Lighting Conditions ◽  
Mustard Oils ◽  
Anthocharis Cardamines

In Shaw & Otto (2020), Shaw described larvae of the butterfly, Orange-tip Anthocharis cardamines (Linnaeus, 1758), that were visually obvious yet apparently immune to bird predation. He speculated that mustard oils in the foodplants may render them distasteful to birds so that being conspicuous is of little consequence, allowing them to bask in sunshine possibly to aid digestion. In contrast, I argue that in certain lighting conditions larger larvae of Orange-tip can be very well camouflaged. These two different defence mechanisms are not mutually exclusive and each may come into play under different conditions of lighting, larval age and/or food-plant availability. For disguise the larvae make use of double-countershading in what Süffert (1932) called the 'two-surface effect'. Here I briefly describe its mechanism along with that of the better-known ordinary (single) countershading. Photographs are shown of both.

The biology of the external surfaces of helminth parasites

1980 ◽  
Vol 79 (1-3) ◽  
pp. 145-172
Author(s):  
L. H. Chappell
Keyword(s):  
Surface Effect ◽  
Parenchymal Cell ◽  
Biological Properties ◽  
Published Data ◽  
Helminth Parasites ◽  
Transport Mechanisms ◽  
Defence Mechanisms ◽  
Canal System ◽  
Surface Transport ◽  
Host Parasite

SynopsisThe biological properties of the surface of helminth parasites are examined under three headings, morphology, digestive-absorptive function and defence. The concept of the host-parasite interface is explored.Platyhelminth parasites are covered by a syncytial tegument with sunken parenchymal cell bodies. The surface is either microvillous or deeply folded, presenting a large surface area relative to volume. The acanthocephalan surface is structurally unique, possessing a branching pore-canal system. The majority of nematodes are surrounded by a thick cuticle composed of distinct layers; exceptions include the entomophilic nematodes.The absorptive properties of the surface of helminth parasites are discussed and the published data on transtegumental transport of nutrient molecules examined. Most nematodes are impermeable to small molecules, but all other helminths utilise surface transport mechanisms. Cestodes and acanthocephalans lack a gut and the tegument becomes the major site of nutrient uptake.Surface-bound enzymes have been described in several helminths and indicate the possible extent of surface digestion by parasites. Binding of host digestive enzymes to the helminth surface may also serve a protective as well as nutritional function.Surface defence mechanisms are described whereby physiological interactions between host and parasite at the helminth surface effect evasion of the host's defences. The essence of these mechanisms is surface disguise.

The Effect of Pentosan Polysulphate (SP54) on the Fibrinolytic Enzyme System - A Human Volunteer and Experimental Animal Study

1985 ◽  
Vol 54 (04) ◽  
pp. 833-837 ◽  
Author(s):  
N A Marsh ◽  
P M Peyser ◽  
L J Creighton ◽  
M Mahmoud ◽  
P J Gaffney
Keyword(s):  
Plasminogen Activator ◽  
Surface Effect ◽  
Ex Vivo ◽  
Vena Cava ◽  
Tissue Type ◽  
Similar Response ◽  
Small Contribution ◽  
Thrombosis Model ◽  
Pentosan Polysulphate

SummaryPentosan polysulphate causes an increase in plasminogen activator activity in plasma both after oral ingestion and after subcutaneous injection. The effect is greatest after 3 h and has disappeared by 6 h. Repeat doses by mouth over 5 days elicit a similar response. The recorded increase in activity is due largely to the release of tissue-type plasminogen activator (tPA) from the endothelium according to the antigen assay although there could be a small contribution from Factor XH-related “intrinsic” fibrinolysis induced in vitro. SP54 enhances activity ex vivo by a non-specific surface effect, and this phenomenon may contribute the increased levels of activity seen in vitro. Administration of SP54 to animals elicits a similar increase in activator activity, the intramuscular route being slightly more effective. Results with an inferior vena cava thrombosis model in the rat suggest that pentosan polysulphate may induce a thrombolytic effect.

Research into the Effect of Photometric Flicker Event on the Perception of Office Workers

2019 ◽  
pp. 22-27
Author(s):  
Cenk Yavuz ◽  
Ceyda Aksoy Tırmıkç ◽  
Burcu Çarklı Yavuz
Keyword(s):  
Experimental Work ◽  
Psychological Problems ◽  
Office Workers ◽  
Questionnaire Study ◽  
Fast Growing ◽  
Lighting Conditions ◽  
Lighting Systems ◽  
Enormous Number

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.

Senior Living - Lighting, Circadian Rhythm and Dementia I

2019 ◽  
pp. 4-8
Author(s):  
Tadej Glažar ◽  
Marjeta Zupancic ◽  
Samo Kralj ◽  
Robert Peternelj
Keyword(s):  
The Elderly ◽  
Living Environment ◽  
Elderly Persons ◽  
Light Spectrum ◽  
Average Life Expectancy ◽  
The Real Estate ◽  
Lighting Conditions ◽  
Light Levels ◽  
Joint Fracture ◽  
Lease Contracts

The Real Estate Fund of Pension and Disability Insurance (Nepremicninski Sklad) in Slovenia, founded in1997 is the owner of 3255 properties in 116 locations throughout the country and is intended for solving housing issues of pensioners of 65 years or older and other elderly persons who are allowed independently to live. The lease contracts are concluded for an indefinite period of time. The aim and vision of the Fund is to improve the quality of life for the elderly tenants by adapting the living environment, the flats and surroundings according to the physical needs of aging tenants. Homes for seniors often have low light levels and poor light spectrum caused by fluorescent or incandescent lighting. Demographic changes in most European countries show rising average life expectancy which means that the number of people with weak visual capacity or visual impairment is increasing. Equally the risks of injuries due to poor lighting conditions are increasing, e.g. missing a step resulting in a hip joint fracture. Better lighting conditions are of critical importance for aging population, as stated also in the recently published CIE227:2017. To facilitate safe environment for the elderly, the Fund in 2013 initiated a lighting research study that should provide facts and evidence for a lighting standard for their own premises.

UJI TARIK HIDRODINAMIKMODEL KAPAL BERSAYAP WiSE DENGAN LAMBUNG DASAR BERSTEP

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Iskendar Iskendar ◽  
Andi Jamaludin ◽  
Paulus Indiyono
Keyword(s):  
Comparative Study ◽  
Model Test ◽  
Hydrodynamic Model ◽  
Surface Effect ◽  
Center Of Gravity ◽  
Test Results ◽  
Flat Bottom ◽  
Towing Tank ◽  
Test Models ◽  
Wetted Surface Area

This paper describes hydrodynamic model tests of Wing in Surface Effect (WiSE) Craft. These craft  was fitted with  stephull  form in different location on longitudinal flat bottom (stepedhull planning craft) to determine the influences of sticking and porpoising motion performances. These motions are usually occured when the craft start to take-off from water surfaces. The test models with scale of 1 : 7 were comprised of 4 (four) stephull models and 1 (one) non-stephull model  as a comparative study. The hydrodynamic  tests were performed with craft speed of 16 – 32 knots (prototype values) in Towing Tank at UPT. Balai Pengkajian dan Penelitian Hidrodinamika (BPPH), BPPT, Surabaya. The resistance (drag) was measured by dynamo meter and the trim of model (draft changing at fore and aft  of model due to model speed) was measured by trim meter. By knowing the value of model trim, the wetted surface area can be determined. Then, the lift forces were calculated based on these measured values. The model test results were presented on tables and curves.  Test results show that models  with step located far away from center of gravity of the WiSE craft tend to porpoising and sticking condition, except if the step location on the below of these center of gravity. While model without step tends to sticking conditions.

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