WorldWideScience

Sample records for mating habits camouflage

  1. Investigation on mating habit and sexual competition ability of Helicoverpa armigera sterilized by irradiation

    International Nuclear Information System (INIS)

    Xia Darong; Yang Rongxin; Gu Weiping; Zhang Yanjun

    1999-01-01

    Mating habit and sexual competition ability of Helicoverpa armigera irradiated with 300 Gy of γ-rays were observed. The results showed that when reared in laboratory, most adults mated at 4-7 o'clock, a small proportion of adults mated at 2-3 o'clock or at 8-9 o'clock in the morning, meanwhile wild population mated two and a half hours earlier than laboratory populations did. No difference in mating habit and sexual competition ability was found between the irradiation-sterilized and normal adults except that the effective mating rate of the former was 61.6%, one third less than that of the latter ones. Most irradiation-sterilized adults mated one time in their whole lives, only a few could mate 2-3 times and even 5 times, indicating that the multi-mating characteristic of Helicoverpa armigera was not changed by irradiation. It can be concluded that irradiated sterile insect technique is feasible for integrated controlling the cotton bollworm

  2. DNA Camouflage

    Science.gov (United States)

    2016-01-08

    1 DNA Camouflage Supplementary Information Bijan Zakeri1,2*, Timothy K. Lu1,2*, Peter A. Carr2,3* 1Department of Electrical Engineering and...ll.mit.edu). Distribution A: Public Release   2 Supplementary Figure 1 DNA camouflage with the 2-state device. (a) In the presence of Cre, DSD-2[α...10 1 + Cre 1 500 1,000 length (bp) chromatogram alignment template − Cre   4 Supplementary Figure 3 DNA camouflage with a switchable

  3. Camouflage for vitiligo.

    Science.gov (United States)

    Tanioka, Miki; Miyachi, Yoshiki

    2009-01-01

    Cosmetic camouflage is indispensable for patients with vitiligo and can result in an improvement of their quality of life. Recent cosmetic advances enabled camouflage to obtain a suitable color match and keep it waterproof. However, camouflage needs some techniques. Therefore, patient education through a camouflage lesson is required to enjoy camouflage. Here the authors introduced a few tips for suitable camouflage, which were devised through camouflage lessons.

  4. Camouflage Chameleons.

    Science.gov (United States)

    Housewright, Mary Kay

    1999-01-01

    Discusses an art activity that has students create pictures in which they first trace a chameleon pattern and then add camouflage to conceal the chameleon. Explains that different materials and techniques are used for students in grades k-1 and 2-5. (CMK)

  5. Habits.

    Science.gov (United States)

    Robbins, T W; Costa, Rui M

    2017-11-20

    What is a habit? One problem with the concept of habit has been that virtually everyone has their own ideas of what is meant by such a term. Whilst not eschewing folk psychology, it is useful to re-examine dictionary definitions of 'habit'. The Oxford Dictionary of English defines habit as "a settled or regular tendency or practice, especially one that is hard to give up" and also "an automatic reaction to a specific situation". The latter, reassuringly, is not too far from what has come to be known as stimulus-response theory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. How camouflage works.

    Science.gov (United States)

    Merilaita, Sami; Scott-Samuel, Nicholas E; Cuthill, Innes C

    2017-07-05

    For camouflage to succeed, an individual has to pass undetected, unrecognized or untargeted, and hence it is the processing of visual information that needs to be deceived. Camouflage is therefore an adaptation to the perception and cognitive mechanisms of another animal. Although this has been acknowledged for a long time, there has been no unitary account of the link between visual perception and camouflage. Viewing camouflage as a suite of adaptations to reduce the signal-to-noise ratio provides the necessary common framework. We review the main processes in visual perception and how animal camouflage exploits these. We connect the function of established camouflage mechanisms to the analysis of primitive features, edges, surfaces, characteristic features and objects (a standard hierarchy of processing in vision science). Compared to the commonly used research approach based on established camouflage mechanisms, we argue that our approach based on perceptual processes targeted by camouflage has several important benefits: specifically, it enables the formulation of more precise hypotheses and addresses questions that cannot even be identified when investigating camouflage only through the classic approach based on the patterns themselves. It also promotes a shift from the appearance to the mechanistic function of animal coloration.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  7. The Art of Camouflage

    Science.gov (United States)

    Martin, Rebecca

    2010-01-01

    The zoo is a favorite field trip destination for young students. This lesson was created for use before their excursion to increase their awareness of camouflage as a pattern design in animals. In this article, the author describes how her students made an art project on camouflage. (Contains 1 online resource.)

  8. Innovative Vehicle Camouflage

    National Research Council Canada - National Science Library

    Vargo, Terrence

    2004-01-01

    The use of painted camouflage patterns on military hardware is a time-tested, cost-effective and practical countermeasure against human vision and aided vision target acquisition systems in many combat scenarios...

  9. Conservation implications of anthropogenic impacts on visual communication and camouflage.

    Science.gov (United States)

    Delhey, Kaspar; Peters, Anne

    2017-02-01

    Anthropogenic environmental impacts can disrupt the sensory environment of animals and affect important processes from mate choice to predator avoidance. Currently, these effects are best understood for auditory and chemosensory modalities, and recent reviews highlight their importance for conservation. We examined how anthropogenic changes to the visual environment (ambient light, transmission, and backgrounds) affect visual communication and camouflage and considered the implications of these effects for conservation. Human changes to the visual environment can increase predation risk by affecting camouflage effectiveness, lead to maladaptive patterns of mate choice, and disrupt mutualistic interactions between pollinators and plants. Implications for conservation are particularly evident for disrupted camouflage due to its tight links with survival. The conservation importance of impaired visual communication is less documented. The effects of anthropogenic changes on visual communication and camouflage may be severe when they affect critical processes such as pollination or species recognition. However, when impaired mate choice does not lead to hybridization, the conservation consequences are less clear. We suggest that the demographic effects of human impacts on visual communication and camouflage will be particularly strong when human-induced modifications to the visual environment are evolutionarily novel (i.e., very different from natural variation); affected species and populations have low levels of intraspecific (genotypic and phenotypic) variation and behavioral, sensory, or physiological plasticity; and the processes affected are directly related to survival (camouflage), species recognition, or number of offspring produced, rather than offspring quality or attractiveness. Our findings suggest that anthropogenic effects on the visual environment may be of similar importance relative to conservation as anthropogenic effects on other sensory modalities

  10. Visible in camouflage of military engineering application

    Science.gov (United States)

    Pu, Huan; Kang, Qing; Chen, Shanjing; Wang, Zhenggang

    2016-03-01

    Our traditional methods of disguise shortcomings, using optical material combined with traditional methods to improve the efficiency of camouflage in disguise. Present lack of effective camouflage effect evaluation system, it refers to Matlab software for optical phase camouflage effect evaluation.

  11. Optimal background matching camouflage.

    Science.gov (United States)

    Michalis, Constantine; Scott-Samuel, Nicholas E; Gibson, David P; Cuthill, Innes C

    2017-07-12

    Background matching is the most familiar and widespread camouflage strategy: avoiding detection by having a similar colour and pattern to the background. Optimizing background matching is straightforward in a homogeneous environment, or when the habitat has very distinct sub-types and there is divergent selection leading to polymorphism. However, most backgrounds have continuous variation in colour and texture, so what is the best solution? Not all samples of the background are likely to be equally inconspicuous, and laboratory experiments on birds and humans support this view. Theory suggests that the most probable background sample (in the statistical sense), at the size of the prey, would, on average, be the most cryptic. We present an analysis, based on realistic assumptions about low-level vision, that estimates the distribution of background colours and visual textures, and predicts the best camouflage. We present data from a field experiment that tests and supports our predictions, using artificial moth-like targets under bird predation. Additionally, we present analogous data for humans, under tightly controlled viewing conditions, searching for targets on a computer screen. These data show that, in the absence of predator learning, the best single camouflage pattern for heterogeneous backgrounds is the most probable sample. © 2017 The Authors.

  12. Hyperspectral discrimination of camouflaged target

    Science.gov (United States)

    Bárta, Vojtěch; Racek, František

    2017-10-01

    The article deals with detection of camouflaged objects during winter season. Winter camouflage is a marginal affair in most countries due to short time period of the snow cover. In the geographical condition of Central Europe the winter period with snow occurs less than 1/12 of year. The LWIR or SWIR spectral areas are used for detection of camouflaged objects. For those spectral regions the difference in chemical composition and temperature express in spectral features. Exploitation of the LWIR and SWIR devices is demanding due to their large dimension and expensiveness. Therefore, the article deals with estimation of utilization of VIS region for detecting of camouflaged object on snow background. The multispectral image output for the various spectral filters is simulated. Hyperspectral indices are determined to detect the camouflaged objects in the winter. The multispectral image simulation is based on the hyperspectral datacube obtained in real conditions.

  13. COSMETIC CAMOUFLAGE IN VITILIGO

    Science.gov (United States)

    Sarveswari, K N

    2010-01-01

    Vitiligo is not a life–threatening nor a contagious disease. But the disfigurement of vitiligo can be devastating to its sufferers, especially dark-skinned individuals. Available treatment options are disappointing and sufferers often use various forms of camouflage. Remedial cosmetic cover creams help conceal the blemish of vitiligo at least temporarily. A high concentration of pigment is incorporated into water–free or anhydrous foundations to give a color that matches the patient’s skin, thereby concealing vitiligo patches. The article highlights the content and technique of application of these creams. PMID:21063508

  14. How Much Does Camouflage Help?

    Science.gov (United States)

    Brunner, Regina Baron; Brunner, Carl E.

    1994-01-01

    Describes an activity which connects mathematics and science by using data analysis and studies of animal camouflage. Includes a reproducible student worksheet to be used for data collection. (11 references) (MKR)

  15. Motion camouflage in three dimensions

    OpenAIRE

    Reddy, P. V.; Justh, E. W.; Krishnaprasad, P. S.

    2006-01-01

    We formulate and analyze a three-dimensional model of motion camouflage, a stealth strategy observed in nature. A high-gain feedback law for motion camouflage is formulated in which the pursuer and evader trajectories are described using natural Frenet frames (or relatively parallel adapted frames), and the corresponding natural curvatures serve as controls. The biological plausibility of the feedback law is discussed, as is its connection to missile guidance. Simulations illustrating motion ...

  16. Active Camouflage for Infantry Headwear Applications

    Science.gov (United States)

    2007-02-01

    Figure 1: Camouflage Types 1.3.1 Visual Camouflage Visual camouflage consists of shape, surface, shine, silhouette, shadow, spacing and movement (Sen...convincing examples of active shape camouflage is the octopus , which can blend into its surroundings not only by changing colour, but also the shape...mimic its surroundings, even adjusting to changes made by movement , so that a soldier becomes nearly invisible. Humansystems® Incorporated Active

  17. A Review Paper on Camouflage Texture Evaluation

    OpenAIRE

    Amol Patil; Girraj Prasad Rathode

    2013-01-01

    Traditional evaluation method of camouflage texture effect is subjective evaluation. It’s very tedious and inconvenient to direct the texture designing. In this project, a systemic and rational method for direction and evaluation of camouflage texture designing is proposed. Camouflage consists of things such as leaves, branches, or brown and green paint, which are used to make it difficult for an enemy to see military forces and equipment. A camouflage texture evaluation method based on WSSIM...

  18. Cultural evolution of military camouflage.

    Science.gov (United States)

    Talas, Laszlo; Baddeley, Roland J; Cuthill, Innes C

    2017-07-05

    While one has evolved and the other been consciously created, animal and military camouflage are expected to show many similar design principles. Using a unique database of calibrated photographs of camouflage uniform patterns, processed using texture and colour analysis methods from computer vision, we show that the parallels with biology are deeper than design for effective concealment. Using two case studies we show that, like many animal colour patterns, military camouflage can serve multiple functions. Following the dissolution of the Warsaw Pact, countries that became more Western-facing in political terms converged on NATO patterns in camouflage texture and colour. Following the break-up of the former Yugoslavia, the resulting states diverged in design, becoming more similar to neighbouring countries than the ancestral design. None of these insights would have been obtained using extant military approaches to camouflage design, which focus solely on concealment. Moreover, our computational techniques for quantifying pattern offer new tools for comparative biologists studying animal coloration.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  19. Optimizing countershading camouflage.

    Science.gov (United States)

    Cuthill, Innes C; Sanghera, N Simon; Penacchio, Olivier; Lovell, Paul George; Ruxton, Graeme D; Harris, Julie M

    2016-11-15

    Countershading, the widespread tendency of animals to be darker on the side that receives strongest illumination, has classically been explained as an adaptation for camouflage: obliterating cues to 3D shape and enhancing background matching. However, there have only been two quantitative tests of whether the patterns observed in different species match the optimal shading to obliterate 3D cues, and no tests of whether optimal countershading actually improves concealment or survival. We use a mathematical model of the light field to predict the optimal countershading for concealment that is specific to the light environment and then test this prediction with correspondingly patterned model "caterpillars" exposed to avian predation in the field. We show that the optimal countershading is strongly illumination-dependent. A relatively sharp transition in surface patterning from dark to light is only optimal under direct solar illumination; if there is diffuse illumination from cloudy skies or shade, the pattern provides no advantage over homogeneous background-matching coloration. Conversely, a smoother gradation between dark and light is optimal under cloudy skies or shade. The demonstration of these illumination-dependent effects of different countershading patterns on predation risk strongly supports the comparative evidence showing that the type of countershading varies with light environment.

  20. Hair camouflage: A comprehensive review.

    Science.gov (United States)

    Saed, Stephanie; Ibrahim, Omer; Bergfeld, Wilma F

    2017-03-01

    Hair is venerated, cherished, and desired in societies throughout the world. Both women and men express their individual identities through their hairstyles. Healthy hair contributes to successful social assimilation, employment, and overall quality of life. Therefore, hair loss can have detrimental effects on almost every aspect of a person's life. In this review, we discuss the myriad of options that aid in concealing and camouflaging hair loss to facilitate a healthier-appearing scalp. Camouflage options for patients who suffer from hair loss include full or partial wigs, hair extensions, concealing powders and sprays, surgical tattoos, and hair transplants. We describe these modalities in detail and discuss their respective advantages and disadvantages.

  1. Camouflage, Color Schemes, and Cubism.

    Science.gov (United States)

    Guhin, Paula

    2002-01-01

    Presents an art activity where students learn about Cubism and color mixing. Explains that the students create camouflaged animals after learning about the work, "Female Torso" (Pablo Picasso). Includes directions for how to create the pictures and states that the assignment can be used with students of all ages. (CMK)

  2. Camouflage, detection and identification of moving targets.

    Science.gov (United States)

    Hall, Joanna R; Cuthill, Innes C; Baddeley, Roland; Shohet, Adam J; Scott-Samuel, Nicholas E

    2013-05-07

    Nearly all research on camouflage has investigated its effectiveness for concealing stationary objects. However, animals have to move, and patterns that only work when the subject is static will heavily constrain behaviour. We investigated the effects of different camouflages on the three stages of predation-detection, identification and capture-in a computer-based task with humans. An initial experiment tested seven camouflage strategies on static stimuli. In line with previous literature, background-matching and disruptive patterns were found to be most successful. Experiment 2 showed that if stimuli move, an isolated moving object on a stationary background cannot avoid detection or capture regardless of the type of camouflage. Experiment 3 used an identification task and showed that while camouflage is unable to slow detection or capture, camouflaged targets are harder to identify than uncamouflaged targets when similar background objects are present. The specific details of the camouflage patterns have little impact on this effect. If one has to move, camouflage cannot impede detection; but if one is surrounded by similar targets (e.g. other animals in a herd, or moving background distractors), then camouflage can slow identification. Despite previous assumptions, motion does not entirely 'break' camouflage.

  3. MATE standardization

    Science.gov (United States)

    Farmer, R. E.

    1982-11-01

    The MATE (Modular Automatic Test Equipment) program was developed to combat the proliferation of unique, expensive ATE within the Air Force. MATE incorporates a standard management approach and a standard architecture designed to implement a cradle-to-grave approach to the acquisition of ATE and to significantly reduce the life cycle cost of weapons systems support. These standards are detailed in the MATE Guides. The MATE Guides assist both the Air Force and Industry in implementing the MATE concept, and provide the necessary tools and guidance required for successful acquisition of ATE. The guides also provide the necessary specifications for industry to build MATE-qualifiable equipment. The MATE architecture provides standards for all key interfaces of an ATE system. The MATE approach to the acquisition and management of ATE has been jointly endorsed by the commanders of Air Force Systems Command and Air Force Logistics Command as the way of doing business in the future.

  4. Yerba Mate

    Science.gov (United States)

    ... high cholesterol who are also taking statin drugs. Obesity. Early research shows that taking yerba mate by mouth might cause weight loss when used in combination with guarana and damiana. Osteoporosis. Drinking a traditional yerba mate tea daily might ...

  5. Transient thermal camouflage and heat signature control

    Science.gov (United States)

    Yang, Tian-Zhi; Su, Yishu; Xu, Weikai; Yang, Xiao-Dong

    2016-09-01

    Thermal metamaterials have been proposed to manipulate heat flux as a new way to cloak or camouflage objects in the infrared world. To date, however, thermal metamaterials only operate in the steady-state and exhibit detectable, transient heat signatures. In this letter, the theoretical basis for a thermal camouflaging technique with controlled transient diffusion is presented. This technique renders an object invisible in real time. More importantly, the thermal camouflaging device instantaneously generates a pre-designed heat signature and behaves as a perfect thermal illusion device. A metamaterial coating with homogeneous and isotropic thermal conductivity, density, and volumetric heat capacity was fabricated and very good camouflaging performance was achieved.

  6. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  7. Dazzle camouflage affects speed perception.

    Directory of Open Access Journals (Sweden)

    Nicholas E Scott-Samuel

    Full Text Available Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called "dazzle camouflage". Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle.

  8. Guidelines for Camouflage Assessment Using Observers

    NARCIS (Netherlands)

    Ronconi, P.; Jacobs, P.A.M.; Mauer, E.; Huebner, G.; Dotoli, P.; Peak, J.E.; Hepfinger, L.; Balma, R.; Christopher, G.; Fleuriet, J.; Honke, T.

    2007-01-01

    The objective of SCI-095 was to advance alternative techniques for determining the camouflage effectiveness of military systems reliably at reduced cost. SCI-095 produced “Guidelines for Camouflage Assessment Using Observers” which is a standardized methodology for observerbased tests and

  9. Evaluation of camouflage effectiveness using hyperspectral images

    Science.gov (United States)

    Zavvartorbati, Ahmad; Dehghani, Hamid; Rashidi, Ali Jabar

    2017-10-01

    Recent advances in camouflage engineering have made it more difficult to detect targets. Assessing the effectiveness of camouflage against different target detection methods leads to identifying the strengths and weaknesses of camouflage designs. One of the target detection methods is to analyze the content of the scene using remote sensing hyperspectral images. In the process of evaluating camouflage designs, there must be comprehensive and efficient evaluation criteria. Three parameters were considered as the main factors affecting the target detection and based on these factors, camouflage effectiveness assessment criteria were proposed. To combine the criteria in the form of a single equation, the equation used in target visual search models was employed and for determining the criteria, a model was presented based on the structure of the computational visual attention systems. Also, in software implementations on the HyMap hyperspectral image, a variety of camouflage levels were created for the real targets in the image. Assessing the camouflage levels using the proposed criteria, comparing and analyzing the results can show that the provided criteria and model are effective for the evaluation of camouflage designs using hyperspectral images.

  10. Design and evaluation of (urban) camouflage

    NARCIS (Netherlands)

    Hogervorst, M.A.; Toet, A.; Jacobs, P.

    2010-01-01

    An international group consisting of several NATO nations participated in a trial in which urban camouflage was developed and compared. First, photographs were taken in and around a small town (arid climate). Next, the different groups derived urban camouflage patterns from these photographs. We

  11. Hair cosmetics and camouflage technics

    Directory of Open Access Journals (Sweden)

    Zahide Eriş Eken

    2014-06-01

    Full Text Available Hair is composed of a mixture of trace elements in small quantities, proteins, lipids and water. Proteins consist of helical polypeptide amino acid molecules. In the hair cells; polypeptide chains of keratin protein would be organized in filaments. In recent years, hair cosmetics showed a significant change and development. The content of shampoos which is used to cleanse the hair has enhanced significantly. Hair conditioner, hair styling products, pomades, brilliantine, and gloss sprays, hair protective products, camouflage products are most commonly used hair cosmetics. Hair shaping procedures are frequently applied.

  12. Cognition and the evolution of camouflage.

    Science.gov (United States)

    Skelhorn, John; Rowe, Candy

    2016-02-24

    Camouflage is one of the most widespread forms of anti-predator defence and prevents prey individuals from being detected or correctly recognized by would-be predators. Over the past decade, there has been a resurgence of interest in both the evolution of prey camouflage patterns, and in understanding animal cognition in a more ecological context. However, these fields rarely collide, and the role of cognition in the evolution of camouflage is poorly understood. Here, we review what we currently know about the role of both predator and prey cognition in the evolution of prey camouflage, outline why cognition may be an important selective pressure driving the evolution of camouflage and consider how studying the cognitive processes of animals may prove to be a useful tool to study the evolution of camouflage, and vice versa. In doing so, we highlight that we still have a lot to learn about the role of cognition in the evolution of camouflage and identify a number of avenues for future research. © 2016 The Author(s).

  13. Evaluating camouflage design using eye movement data.

    Science.gov (United States)

    Lin, Chiuhsiang Joe; Chang, Chi-Chan; Lee, Yung-Hui

    2014-05-01

    This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  14. An empirical method for dynamic camouflage assessment

    Science.gov (United States)

    Blitch, John G.

    2011-06-01

    As camouflage systems become increasingly sophisticated in their potential to conceal military personnel and precious cargo, evaluation methods need to evolve as well. This paper presents an overview of one such attempt to explore alternative methods for empirical evaluation of dynamic camouflage systems which aspire to keep pace with a soldier's movement through rapidly changing environments that are typical of urban terrain. Motivating factors are covered first, followed by a description of the Blitz Camouflage Assessment (BCA) process and results from an initial proof of concept experiment conducted in November 2006. The conclusion drawn from these results, related literature and the author's personal experience suggest that operational evaluation of personal camouflage needs to be expanded beyond its foundation in signal detection theory and embrace the challenges posed by high levels of cognitive processing.

  15. INFLUENCE OF ART ON THE CAMOUFLAGE DESIGN

    Directory of Open Access Journals (Sweden)

    TACHEV Momchil

    2015-06-01

    Full Text Available Research is focused on the impact of artistic styles and evolution of XX-th century art upon main formal characteristic of older and modern camouflage patterns. In the beginning of the period (1915- 1918, the main principles that have been used are those of boundery and simultaneous contrast, targeting at an effect of relief and non-homogeneity and decomposition. The first stage in camouflage evolution was the attempt to “dazzle” and confuse enemy by creating a false form characteristic. It was used for big military objects –ships, planes. Armies hired a lot of artists with the task to design camouflage schemes. Due to the trend for entrenchment in World War I the first approaches for camouflage most visual parts of the soldiers body are made. Logically, these efforts follow the same principles of visual illusion developed and modified in style, close to the one which was used for the larger objects. The German army prefers geometrical styles while Great Britain and French armed forces choose more expressionistic manner for their camouflage patterns. For the creation of the camouflage patterns, several optic principles and visual illusion are being used. The target is to create a visual illusion for complexity and shape sharpness by breaking down the silhouette unity until visual illusion of merge with the nature.

  16. Propagation characteristic of THz wave in camouflage net material

    Science.gov (United States)

    Dong, Hailong; Wang, Jiachun; Chen, Zongsheng; Lin, Zhidan; Zhao, Dapeng; Liu, Ruihuang

    2017-10-01

    Terahertz (THz) radar system, with excellent potentials such as high-resolution and strong penetration capability, is promising in the field of anti-camouflage. Camouflage net is processed by cutting the camouflage net material, which is fabricated on pre-processing substrate by depositing coatings with camouflage abilities in different bands, such as visible, infrared and radar. In this paper, we concentrate on the propagation characteristic of THz wave in camouflage net material. Firstly, function and structure of camouflage net were analyzed. Then the advantage and appliance of terahertz time-domain spectroscopy (THz-TDS) was introduced. And the relevant experiments were conducted by utilizing THz-TDS. The results obtained indicate that THz wave has better penetration capacity in camouflage net material, which demonstrates the feasibility of using THz radar to detect those targets covered with camouflage net.

  17. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up......A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....

  18. Reverse Engineering Camouflaged Sequential Integrated Circuits Without Scan Access

    OpenAIRE

    Massad, Mohamed El; Garg, Siddharth; Tripunitara, Mahesh

    2017-01-01

    Integrated circuit (IC) camouflaging is a promising technique to protect the design of a chip from reverse engineering. However, recent work has shown that even camouflaged ICs can be reverse engineered from the observed input/output behaviour of a chip using SAT solvers. However, these so-called SAT attacks have so far targeted only camouflaged combinational circuits. For camouflaged sequential circuits, the SAT attack requires that the internal state of the circuit is controllable and obser...

  19. Barriers to Implementing a Single Joint Combat Camouflage Uniform

    Science.gov (United States)

    2017-12-01

    opportunities, threats (SWOT), and political, economic, social, and technological (PEST) analyses; examines the requirements and role of each of the...SUBJECT TERMS ground combat uniform, combat camouflage uniform history , combat camouflage uniform pattern, camouflage pattern testing 15. NUMBER...methodology applies strengths, weaknesses, opportunities, threats (SWOT), and political, economic, social, and technological (PEST) analyses

  20. Hardening Logic Encryption against Key Extraction Attacks with Circuit Camouflage

    Science.gov (United States)

    2017-03-01

    camouflage; obfuscation; SAT; key extraction; reverse engineering ; security; trusted electronics Introduction Integrated Circuit (IC) designs are... Circuit camouflage is hardware obfuscation technology that prevents reverse engineering of a fabricated device by utilizing a relatively small...obfuscated with circuit camouflage technology, this type of attack becomes much more difficult because a reverse engineer cannot extract a gate- level

  1. Development of Instrumental Techniques for Color Assessment of Camouflage Patterns

    Science.gov (United States)

    Fang, Gang

    2012-01-01

    Camouflage fabrics are produced on a large scale for use in the US military and other applications. One of the highest volume camouflage fabrics is known as the Universal Camouflage Pattern (UCP) which is produced for the US Department of Defense. At present, no standard measurement-based color quality control method exists for camouflage…

  2. Structured thermal surface for radiative camouflage.

    Science.gov (United States)

    Li, Ying; Bai, Xue; Yang, Tianzhi; Luo, Hailu; Qiu, Cheng-Wei

    2018-01-18

    Thermal camouflage has been successful in the conductive regime, where thermal metamaterials embedded in a conductive system can manipulate heat conduction inside the bulk. Most reported approaches are background-dependent and not applicable to radiative heat emitted from the surface of the system. A coating with engineered emissivity is one option for radiative camouflage, but only when the background has uniform temperature. Here, we propose a strategy for radiative camouflage of external objects on a given background using a structured thermal surface. The device is non-invasive and restores arbitrary background temperature distributions on its top. For many practical candidates of the background material with similar emissivity as the device, the object can thereby be radiatively concealed without a priori knowledge of the host conductivity and temperature. We expect this strategy to meet the demands of anti-detection and thermal radiation manipulation in complex unknown environments and to inspire developments in phononic and photonic thermotronics.

  3. Siim Nestor soovitab : Turbodisko. Camouflage / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2006-01-01

    Üritusest "Turbodisko" 2. dets. Tallinnas KuKu klubis, indieansambli Bad Apples heliplaadi "When Colours Become Day and Night" (plaadifirmalt Seksound) esitluskontserdist. Saksamaa futuelektroonika ansambli Camouflage albumi "Relocated" esitluskontserdist 3. dets klubis Hollywood (kontserti soojendab läti ansambel STandArt)

  4. Camouflage and Clutch Survival in Plovers and Terns

    Science.gov (United States)

    Stoddard, Mary Caswell; Kupán, Krisztina; Eyster, Harold N.; Rojas-Abreu, Wendoly; Cruz-López, Medardo; Serrano-Meneses, Martín Alejandro; Küpper, Clemens

    2016-09-01

    Animals achieve camouflage through a variety of mechanisms, of which background matching and disruptive coloration are likely the most common. Although many studies have investigated camouflage mechanisms using artificial stimuli and in lab experiments, less work has addressed camouflage in the wild. Here we examine egg camouflage in clutches laid by ground-nesting Snowy Plovers Charadrius nivosus and Least Terns Sternula antillarum breeding in mixed aggregations at Bahía de Ceuta, Sinaloa, Mexico. We obtained digital images of clutches laid by both species. We then calibrated the images and used custom computer software and edge detection algorithms to quantify measures related to three potential camouflage mechanisms: pattern complexity matching, disruptive effects and background color matching. Based on our image analyses, Snowy Plover clutches, in general, appeared to be more camouflaged than Least Tern clutches. Snowy Plover clutches also survived better than Least Tern clutches. Unexpectedly, variation in clutch survival was not explained by any measure of egg camouflage in either species. We conclude that measures of egg camouflage are poor predictors of clutch survival in this population. The behavior of the incubating parents may also affect clutch predation. Determining the significance of egg camouflage requires further testing using visual models and behavioral experiments.

  5. Strategies of Human Mating

    Directory of Open Access Journals (Sweden)

    David M. Buss

    2006-12-01

    Full Text Available Modern humans have inherited the mating strategies that led to the success of their ancestors. These strategies include long-term mating, short-term mating, extra-pair mating, mate poaching, and mate guarding. This article presents empirical evidence supporting evolution-based hypotheses about the complexities of these mating strategies. Since men and women historically confronted different adaptive problems in the mating domain, the sexes differ profoundly in evolved strategic solutions. These differences include possessing different mate preferences, different desires for short-term mating, and differences in the triggers that evoke sexual jealousy. The study of human mating is one of the “success stories” of evolutionary psychology.

  6. Thermal transmission of camouflage nets revisited

    Science.gov (United States)

    Jersblad, Johan; Jacobs, Pieter

    2016-10-01

    In this article we derive, from first principles, the correct formula for thermal transmission of a camouflage net, based on the setup described in the US standard for lightweight camouflage nets. Furthermore, we compare the results and implications with the use of an incorrect formula that have been seen in several recent tenders. It is shown that the incorrect formulation not only gives rise to large errors, but the result also depends on the surrounding room temperature, which in the correct derivation cancels out. The theoretical results are compared with laboratory measurements. The theoretical results agree with the laboratory results for the correct derivation. To summarize we discuss the consequences for soldiers on the battlefield if incorrect standards and test methods are used in procurement processes.

  7. Rockpool gobies change colour for camouflage.

    Directory of Open Access Journals (Sweden)

    Martin Stevens

    Full Text Available Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks or rapid (seconds and minutes colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white, and of different colours (red and blue and use digital image analysis and modelling of predator (avian vision to quantify colour and luminance (perceived lightness changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute, and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

  8. Rockpool gobies change colour for camouflage.

    Science.gov (United States)

    Stevens, Martin; Lown, Alice E; Denton, Alexander M

    2014-01-01

    Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

  9. Establishing the behavioural limits for countershaded camouflage.

    Science.gov (United States)

    Penacchio, Olivier; Harris, Julie M; Lovell, P George

    2017-10-20

    Countershading is a ubiquitous patterning of animals whereby the side that typically faces the highest illumination is darker. When tuned to specific lighting conditions and body orientation with respect to the light field, countershading minimizes the gradient of light the body reflects by counterbalancing shadowing due to illumination, and has therefore classically been thought of as an adaptation for visual camouflage. However, whether and how crypsis degrades when body orientation with respect to the light field is non-optimal has never been studied. We tested the behavioural limits on body orientation for countershading to deliver effective visual camouflage. We asked human participants to detect a countershaded target in a simulated three-dimensional environment. The target was optimally coloured for crypsis in a reference orientation and was displayed at different orientations. Search performance dramatically improved for deviations beyond 15 degrees. Detection time was significantly shorter and accuracy significantly higher than when the target orientation matched the countershading pattern. This work demonstrates the importance of maintaining body orientation appropriate for the displayed camouflage pattern, suggesting a possible selective pressure for animals to orient themselves appropriately to enhance crypsis.

  10. Color change, phenotypic plasticity, and camouflage

    Directory of Open Access Journals (Sweden)

    Martin eStevens

    2016-05-01

    Full Text Available The ability to change appearance over a range of timescales is widespread in nature, existing in many invertebrate and vertebrate groups. This can include color change occurring in seconds, minutes, and hours, to longer term changes associated with phenotypic plasticity and development. A major function is for camouflage against predators because color change and plasticity enables animals to match their surroundings and potentially reduce the risk of predation. Recently, we published findings (Stevens et al. 2014a showing how shore crabs can change their appearance and better match the background to predator vision in the short term. This, coupled with a number of past studies, emphasizes the potential that animals have to modify their appearance for camouflage. However, the majority of studies on camouflage and color plasticity have focused on a small number of species capable of unusually rapid changes. There are many broad questions that remain about the nature, mechanisms, evolution, and adaptive value of color change and plasticity for concealment. Here, I discuss past work and outline six questions relating to color change and plasticity, as well as major avenues for future work.

  11. Camouflage as Communicator of Survivor Mentality in Contemporary Popular Music

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2010-01-01

    Michael A. Langkjær wants to know why military style in general and camouflage in particular have become true pillars of pop and rock culture. How is this prolonged influence to be explained? He places rock and camouflage in the larger framework of "military rock" since the sixties. Contrary to w...

  12. Testing for Camouflage Using Virtual Prey and Human "Predators"

    Science.gov (United States)

    Todd, Peter A.

    2009-01-01

    Camouflage is a prevalent feature of the natural world and as such has a ready appeal to students; however, it is a difficult subject to study using real predators and prey. This paper focuses how one fundamental type of camouflage, disruptive colouration (bold markings that break up the outline of the organism), can be tested using paper…

  13. Urban camouflage assessment through visual search and computational saliency

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2013-01-01

    We present a new method to derive a multiscale urban camouflage pattern from a given set of background image samples. We applied this method to design a camouflage pattern for a given (semi-arid) urban environment. We performed a human visual search experiment and a computational evaluation study to

  14. Infrared image simulation for estimating the effectiveness of camouflage measures

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.S. [Seoul National University Graduate School, Seoul (Korea); Kauh, S.K. [Seoul National University, Seoul (Korea); Yoo, H.S. [Soong Sil University, Seoul (Korea)

    1999-08-01

    Camouflage measures in military purpose utilize the apparent temperature difference between target and background, so it is essential to develop a thermal analysis program for apparent temperature predictions and to apply some camouflage measures to real military targets for camouflage purpose. In this study, a thermal analysis program including conduction, convection and radiation is developed and the validity of radiation heat transfer terms is examined. The results show that longwave radiation along with solar radiation should be included in order to predict the apparent temperature as well as the physical temperature precisely. Longwave emissivity variation as an effective surface treatment, such as painting of a less emissive material or camouflage clothing, may provide a temperature similarity or a spatial similarity, resulting in an effective camouflage. (author). 12 refs., 15 figs., 2 tabs.

  15. Camouflage predicts survival in ground-nesting birds.

    Science.gov (United States)

    Troscianko, Jolyon; Wilson-Aggarwal, Jared; Stevens, Martin; Spottiswoode, Claire N

    2016-01-29

    Evading detection by predators is crucial for survival. Camouflage is therefore a widespread adaptation, but despite substantial research effort our understanding of different camouflage strategies has relied predominantly on artificial systems and on experiments disregarding how camouflage is perceived by predators. Here we show for the first time in a natural system, that survival probability of wild animals is directly related to their level of camouflage as perceived by the visual systems of their main predators. Ground-nesting plovers and coursers flee as threats approach, and their clutches were more likely to survive when their egg contrast matched their surrounds. In nightjars - which remain motionless as threats approach - clutch survival depended on plumage pattern matching between the incubating bird and its surrounds. Our findings highlight the importance of pattern and luminance based camouflage properties, and the effectiveness of modern techniques in capturing the adaptive properties of visual phenotypes.

  16. Quantitative habitability.

    Science.gov (United States)

    Shock, Everett L; Holland, Melanie E

    2007-12-01

    A framework is proposed for a quantitative approach to studying habitability. Considerations of environmental supply and organismal demand of energy lead to the conclusions that power units are most appropriate and that the units for habitability become watts per organism. Extreme and plush environments are revealed to be on a habitability continuum, and extreme environments can be quantified as those where power supply only barely exceeds demand. Strategies for laboratory and field experiments are outlined that would quantify power supplies, power demands, and habitability. An example involving a comparison of various metabolisms pursued by halophiles is shown to be well on the way to a quantitative habitability analysis.

  17. Habit formation.

    Science.gov (United States)

    Smith, Kyle S; Graybiel, Ann M

    2016-03-01

    Habits, both good ones and bad ones, are pervasive in animal behavior. Important frameworks have been developed to understand habits through psychological and neurobiological studies. This work has given us a rich understanding of brain networks that promote habits, and has also helped us to understand what constitutes a habitual behavior as opposed to a behavior that is more flexible and prospective. Mounting evidence from studies using neural recording methods suggests that habit formation is not a simple process. We review this evidence and take the position that habits could be sculpted from multiple dissociable changes in neural activity. These changes occur across multiple brain regions and even within single brain regions. This strategy of classifying components of a habit based on different brain signals provides a potentially useful new way to conceive of disorders that involve overly fixed behaviors as arising from different potential dysfunctions within the brain's habit network.

  18. Habit formation

    Science.gov (United States)

    Smith, Kyle S.; Graybiel, Ann M.

    2016-01-01

    Habits, both good ones and bad ones, are pervasive in animal behavior. Important frameworks have been developed to understand habits through psychological and neurobiological studies. This work has given us a rich understanding of brain networks that promote habits, and has also helped us to understand what constitutes a habitual behavior as opposed to a behavior that is more flexible and prospective. Mounting evidence from studies using neural recording methods suggests that habit formation is not a simple process. We review this evidence and take the position that habits could be sculpted from multiple dissociable changes in neural activity. These changes occur across multiple brain regions and even within single brain regions. This strategy of classifying components of a habit based on different brain signals provides a potentially useful new way to conceive of disorders that involve overly fixed behaviors as arising from different potential dysfunctions within the brain's habit network. PMID:27069378

  19. Microhabitat choice in island lizards enhances camouflage against avian predators.

    Science.gov (United States)

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-25

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.

  20. Geographic Variation in Camouflage Specialization by a Decorator Crab.

    Science.gov (United States)

    Stachowicz, John J; Hay, Mark E

    2000-07-01

    In North Carolina, the decorator crab Libinia dubia camouflages almost exclusively with the chemically noxious alga Dictyota menstrualis. By placing this alga on its carapace, the crab behaviorally sequesters the defensive chemicals of the plant and gains protection from omnivorous consumers. However, Dictyota is absent north of North Carolina, whereas Libinia occurs as far north as New England. Crabs from three northern locations where Dictyota is absent (Rhode Island, Connecticut, and New Jersey) camouflaged to match their environment, rather than selectively accumulating any one species. When D. menstrualis was offered to crabs from northern sites, they did not distinguish between it and other seaweeds for camouflage, whereas crabs from Alabama and two locations in North Carolina used D. menstrualis almost exclusively. In addition, in winter and spring, when Dictyota was seasonally absent in North Carolina, Libinia selectively camouflaged with the sun sponge Hymeniacidon heliophila, which was chemically unpalatable to local fishes. Thus, southern crabs were consistent specialists on chemically defended species for camouflage, while northern crabs were more generalized. The geographic shift in crab behavior away from specialization coincides with a reported decrease in both total predation pressure and the frequency of omnivorous consumers. These shifts in the nature and intensity of predation pressure may favor different camouflage strategies (generalist vs. specialist), contributing to the observed geographic differences in camouflage behavior.

  1. Compatibility of Mating Preferences

    OpenAIRE

    Bingol, Haluk O.; Basar, Omer

    2016-01-01

    Human mating is a complex phenomenon. Although men and women have different preferences in mate selection, there should be compatibility in these preferences since human mating requires agreement of both parties. We investigate how compatible the mating preferences of men and women are in a given property such as age, height, education and income. We use dataset of a large online dating site (N = 44, 255 users). (i) Our findings are based on the "actual behavior" of users trying to find a dat...

  2. Male mating biology

    NARCIS (Netherlands)

    Howell, Paul I.; Knols, Bart G. J.

    2009-01-01

    Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings

  3. Scattering Manipulation and Camouflage of Electrically Small Objects through Metasurfaces

    Science.gov (United States)

    Vellucci, S.; Monti, A.; Toscano, A.; Bilotti, F.

    2017-03-01

    In this paper, we discuss the intriguing possibility of tailoring the scattering response of an electrically small object for camouflage and illusion applications using metasurfaces. As a significant example, we focus our attention on the cylindrical geometry and derive the analytical conditions needed to camouflage the geometrical and electrical characteristics of dielectric and metallic cylinders coated with ideal metasurfaces. A closed-form expression of the camouflaging metasurface depending on the cylinder's characteristics is derived. Furthermore, the frequency behavior and the limitations of this technique are discussed with the aid of relevant examples. In order to overcome these limitations, a solution based on the use of lossy metasurfaces is proposed.

  4. Animal behaviour and algal camouflage jointly structure predation and selection.

    Science.gov (United States)

    Start, Denon

    2018-05-01

    Trait variation can structure interactions between individuals, thus shaping selection. Although antipredator strategies are an important component of many aquatic systems, how multiple antipredator traits interact to influence consumption and selection remains contentious. Here, I use a common larval dragonfly (Epitheca canis) and its predator (Anax junius) to test for the joint effects of activity rate and algal camouflage on predation and survival selection. I found that active and poorly camouflaged Epitheca were more likely to be consumed, and thus, survival selection favoured inactive and well-camouflaged individuals. Notably, camouflage dampened selection on activity rate, likely by reducing attack rates when Epitheca encountered a predator. Correlational selection is therefore conferred by the ecological interaction of traits, rather than by opposing selection acting on linked traits. I suggest that antipredator traits with different adaptive functions can jointly structure patterns of consumption and selection. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  5. Camouflage during movement in the European cuttlefish (Sepia officinalis).

    Science.gov (United States)

    Josef, Noam; Berenshtein, Igal; Fiorito, Graziano; Sykes, António V; Shashar, Nadav

    2015-11-01

    A moving object is considered conspicuous because of the movement itself. When moving from one background to another, even dynamic camouflage experts such as cephalopods should sacrifice their extraordinary camouflage. Therefore, minimizing detection at this stage is crucial and highly beneficial. In this study, we describe a background-matching mechanism during movement, which aids the cuttlefish to downplay its presence throughout movement. In situ behavioural experiments using video and image analysis, revealed a delayed, sigmoidal, colour-changing mechanism during movement of Sepia officinalis across uniform black and grey backgrounds. This is a first important step in understanding dynamic camouflage during movement, and this new behavioural mechanism may be incorporated and applied to any dynamic camouflaging animal or man-made system on the move. © 2015. Published by The Company of Biologists Ltd.

  6. Analysis of the Thermal Shielding Properties of Camouflage Materials

    National Research Council Canada - National Science Library

    Bennett, John G; Polsen, Erik S

    2007-01-01

    .... The outer surface of each panel was thermostatically controlled to the same temperature. The camouflage material covered one of the panels, while the other, uncovered, panel acted as the baseline...

  7. Experimental Investigation of Polyurethane Camouflage Coating Using Dynamic Mechanical Analysis

    National Research Council Canada - National Science Library

    Crawford, Dawn

    1999-01-01

    .... The current polyurethane solvent-based (SOL) formulation, used as a chemical-agent-resistant camouflage top coat on all military tactical vehicles, was investigated, along with newly developed water-reducible (WR...

  8. Modeling apparent color for visual evaluation of camouflage fabrics

    Science.gov (United States)

    Ramsey, S.; Mayo, T.; Shabaev, A.; Lambrakos, S. G.

    2017-08-01

    As the U.S. Navy, Army, and Special Operations Forces progress towards fielding more advanced uniforms with multi-colored and highly detailed camouflage patterning, additional test methodologies are necessary in evaluating color in these types of camouflage textiles. The apparent color is the combination of all visible wavelengths (380-760 nm) of light reflected from large (>=1m2 ) fabric sample sizes for a given standoff distance (10-25ft). Camouflage patterns lose resolution with increasing standoff distance, and eventually all colors within the pattern appear monotone (the "apparent color" of the pattern). This paper presents an apparent color prediction model that can be used for evaluation of camouflage fabrics.

  9. Using satellite imagery to evaluate land-based camouflage assets

    CSIR Research Space (South Africa)

    Baumbach, J

    2006-02-01

    Full Text Available to Evaluate Land-based Camouflage Assets J BAUMBACH, M LUBBE CSIR Defence, Peace, Safety and security, PO Box 395, Pretoria, 0001, South Africa Email: jbaumbac@csir.co.za ABSTRACT A camouflage field trial experiment was conducted. For the experiment... analysis, change detection, un-supervised classification, supervised classification and object based classification. RESULTS The following table shows a summary of the different targets, and whether it was detected ( ) or not detected (x), using...

  10. Motion dazzle and camouflage as distinct anti-predator defenses

    Directory of Open Access Journals (Sweden)

    Stevens Martin

    2011-11-01

    Full Text Available Abstract Background Camouflage patterns that hinder detection and/or recognition by antagonists are widely studied in both human and animal contexts. Patterns of contrasting stripes that purportedly degrade an observer's ability to judge the speed and direction of moving prey ('motion dazzle' are, however, rarely investigated. This is despite motion dazzle having been fundamental to the appearance of warships in both world wars and often postulated as the selective agent leading to repeated patterns on many animals (such as zebra and many fish, snake, and invertebrate species. Such patterns often appear conspicuous, suggesting that protection while moving by motion dazzle might impair camouflage when stationary. However, the relationship between motion dazzle and camouflage is unclear because disruptive camouflage relies on high-contrast markings. In this study, we used a computer game with human subjects detecting and capturing either moving or stationary targets with different patterns, in order to provide the first empirical exploration of the interaction of these two protective coloration mechanisms. Results Moving targets with stripes were caught significantly less often and missed more often than targets with camouflage patterns. However, when stationary, targets with camouflage markings were captured less often and caused more false detections than those with striped patterns, which were readily detected. Conclusions Our study provides the clearest evidence to date that some patterns inhibit the capture of moving targets, but that camouflage and motion dazzle are not complementary strategies. Therefore, the specific coloration that evolves in animals will depend on how the life history and ontogeny of each species influence the trade-off between the costs and benefits of motion dazzle and camouflage.

  11. Motion dazzle and camouflage as distinct anti-predator defenses.

    Science.gov (United States)

    Stevens, Martin; Searle, W Tom L; Seymour, Jenny E; Marshall, Kate L A; Ruxton, Graeme D

    2011-11-25

    Camouflage patterns that hinder detection and/or recognition by antagonists are widely studied in both human and animal contexts. Patterns of contrasting stripes that purportedly degrade an observer's ability to judge the speed and direction of moving prey ('motion dazzle') are, however, rarely investigated. This is despite motion dazzle having been fundamental to the appearance of warships in both world wars and often postulated as the selective agent leading to repeated patterns on many animals (such as zebra and many fish, snake, and invertebrate species). Such patterns often appear conspicuous, suggesting that protection while moving by motion dazzle might impair camouflage when stationary. However, the relationship between motion dazzle and camouflage is unclear because disruptive camouflage relies on high-contrast markings. In this study, we used a computer game with human subjects detecting and capturing either moving or stationary targets with different patterns, in order to provide the first empirical exploration of the interaction of these two protective coloration mechanisms. Moving targets with stripes were caught significantly less often and missed more often than targets with camouflage patterns. However, when stationary, targets with camouflage markings were captured less often and caused more false detections than those with striped patterns, which were readily detected. Our study provides the clearest evidence to date that some patterns inhibit the capture of moving targets, but that camouflage and motion dazzle are not complementary strategies. Therefore, the specific coloration that evolves in animals will depend on how the life history and ontogeny of each species influence the trade-off between the costs and benefits of motion dazzle and camouflage.

  12. Camouflage through colour change: mechanisms, adaptive value and ecological significance.

    Science.gov (United States)

    Duarte, Rafael C; Flores, Augusto A V; Stevens, Martin

    2017-07-05

    Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary-ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Authors.

  13. Is countershading camouflage robust to lighting change due to weather?

    Science.gov (United States)

    Penacchio, Olivier; Lovell, P George; Harris, Julie M

    2018-02-01

    Countershading is a pattern of coloration thought to have evolved in order to implement camouflage. By adopting a pattern of coloration that makes the surface facing towards the sun darker and the surface facing away from the sun lighter, the overall amount of light reflected off an animal can be made more uniformly bright. Countershading could hence contribute to visual camouflage by increasing background matching or reducing cues to shape. However, the usefulness of countershading is constrained by a particular pattern delivering 'optimal' camouflage only for very specific lighting conditions. In this study, we test the robustness of countershading camouflage to lighting change due to weather, using human participants as a 'generic' predator. In a simulated three-dimensional environment, we constructed an array of simple leaf-shaped items and a single ellipsoidal target 'prey'. We set these items in two light environments: strongly directional 'sunny' and more diffuse 'cloudy'. The target object was given the optimal pattern of countershading for one of these two environment types or displayed a uniform pattern. By measuring detection time and accuracy, we explored whether and how target detection depended on the match between the pattern of coloration on the target object and scene lighting. Detection times were longest when the countershading was appropriate to the illumination; incorrectly camouflaged targets were detected with a similar pattern of speed and accuracy to uniformly coloured targets. We conclude that structural changes in light environment, such as caused by differences in weather, do change the effectiveness of countershading camouflage.

  14. Egg-laying substrate selection for optimal camouflage by quail.

    Science.gov (United States)

    Lovell, P George; Ruxton, Graeme D; Langridge, Keri V; Spencer, Karen A

    2013-02-04

    Camouflage is conferred by background matching and disruption, which are both affected by microhabitat. However, microhabitat selection that enhances camouflage has only been demonstrated in species with discrete phenotypic morphs. For most animals, phenotypic variation is continuous; here we explore whether such individuals can select microhabitats to best exploit camouflage. We use substrate selection in a ground-nesting bird (Japanese quail, Coturnix japonica). For such species, threat from visual predators is high and egg appearance shows strong between-female variation. In quail, variation in appearance is particularly obvious in the amount of dark maculation on the light-colored shell. When given a choice, birds consistently selected laying substrates that made visual detection of their egg outline most challenging. However, the strategy for maximizing camouflage varied with the degree of egg maculation. Females laying heavily maculated eggs selected the substrate that more closely matched egg maculation color properties, leading to camouflage through disruptive coloration. For lightly maculated eggs, females chose a substrate that best matched their egg background coloration, suggesting background matching. Our results show that quail "know" their individual egg patterning and seek out a nest position that provides most effective camouflage for their individual phenotype. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Habitable Trinity

    Directory of Open Access Journals (Sweden)

    James M. Dohm

    2015-01-01

    Full Text Available Habitable Trinity is a newly proposed concept of a habitable environment. This concept indicates that the coexistence of an atmosphere (consisting largely of C and N, an ocean (H and O, and a landmass (supplier of nutrients accompanying continuous material circulation between these three components driven by the Sun is one of the minimum requirements for life to emerge and evolve. The life body consists of C, O, H, N and other various nutrients, and therefore, the presence of water, only, is not a sufficient condition. Habitable Trinity environment must be maintained to supply necessary components for life body. Our Habitable Trinity concept can also be applied to other planets and moons such as Mars, Europa, Titan, and even exoplanets as a useful index in the quest for life-containing planetary bodies.

  16. Evaluation criteria for spectral design of camouflage

    Science.gov (United States)

    Škerlind, Christina; Fagerström, Jan; Hallberg, Tomas; Kariis, Hans

    2015-10-01

    In development of visual (VIS) and infrared (IR) camouflage for signature management, the aim is the design of surface properties of an object to spectrally match or adapt to a background and thereby minimizing the contrast perceived by a threatening sensor. The so called 'ladder model" relates the requirements for task measure of effectiveness with surface structure properties through the steps signature effectiveness and object signature. It is intended to link materials properties via platform signature to military utility and vice versa. Spectral design of a surface intends to give it a desired wavelength dependent optical response to fit a specific application of interest. Six evaluation criteria were stated, with the aim to aid the process to put requirement on camouflage and for evaluation. The six criteria correspond to properties such as reflectance, gloss, emissivity, and degree of polarization as well as dynamic properties, and broadband or multispectral properties. These criteria have previously been exemplified on different kinds of materials and investigated separately. Anderson and Åkerlind further point out that the six criteria rarely were considered or described all together in one and same publication previously. The specific level of requirement of the different properties must be specified individually for each specific situation and environment to minimize the contrast between target and a background. The criteria or properties are not totally independent of one another. How they are correlated is part of the theme of this paper. However, prioritization has been made due to the limit of space. Therefore all of the interconnections between the six criteria will not be considered in the work of this report. The ladder step previous to digging into the different material composition possibilities and choice of suitable materials and structures (not covered here), includes the object signature and decision of what the spectral response should be

  17. Camouflage for patients with vitiligo vulgaris improved their quality of life.

    Science.gov (United States)

    Tanioka, Miki; Yamamoto, Yosuke; Kato, Mayumi; Miyachi, Yoshiki

    2010-03-01

    Cosmetic camouflage is important for patients with vitiligo vulgaris. However, few studies have investigated its benefit for vitiligo patients. To analyze the psychological effects on patients with vitiligo vulgaris by camouflage lessons performed in vitiligo clinics in Kyoto University Hospital and Fukui Red Cross Hospital, Dermatological Life Quality Index (DLQI) questionnaires were collected before and 1 month after camouflage lessons. Patients with vitiligo vulgaris, who visited our clinics in 2008 and had never experienced camouflage, were enrolled in this study. They took camouflage lessons and continued subsequent self-camouflage for 1 month. Control patients took no lessons and no camouflage. Camouflage improved the scores of DLQI when compared with those without camouflage (P = 0.005). Camouflage improved DLQI scores from 5.90 to 4.48. In DLQI subcategories, camouflage lessons improved a subcategory of "symptoms and feelings" (P = 0.0037). These data supported the idea that camouflage for patients with vitiligo not only covers the white patches but also improves their quality of life.

  18. Low-impact mating system

    Science.gov (United States)

    Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

    2009-01-01

    An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

  19. Colour change and camouflage in juvenile shore crabs Carcinus maenas

    Directory of Open Access Journals (Sweden)

    Martin eStevens

    2014-05-01

    Full Text Available Camouflage is perhaps the most widespread anti-predator defense in nature, with many different types thought to exist. Of these, resembling the general color and pattern of the background (background matching is likely to be the most common. Background matching can be achieved by adaptation of individual appearance to different habitats or substrates, behavioral choice, and color change. Although the ability to change coloration for camouflage over a period of hours or days is likely to be widely found among animals, few studies have quantified this against different backgrounds. Here, we test whether juvenile shore crabs (Carcinus maenas are capable of color change for camouflage by placing them on either black or white (experiment 1 or red and green (experiment 2 backgrounds. We find that crabs are capable of significant changes in brightness, becoming lighter on white backgrounds and darker on black backgrounds. Using models of predator (avian vision, we show that these differences are large enough in many individuals to lead to perceptible changes in appearance. Furthermore, comparisons of crabs with the backgrounds show that changes are likely to lead to significant improvements in camouflage and potentially reduced detection probabilities. Crabs underwent some changes on the red and green backgrounds, but visual modeling indicated that these changes were very small and unlikely to be detectable. Our experiment shows that crabs are able to adjust their camouflage by changes in brightness over a period of hours, and that this could influence detection probability by predators.

  20. Defeating crypsis: detection and learning of camouflage strategies.

    Directory of Open Access Journals (Sweden)

    Jolyon Troscianko

    Full Text Available Camouflage is perhaps the most widespread defence against predators in nature and an active area of interdisciplinary research. Recent work has aimed to understand what camouflage types exist (e.g. background matching, disruptive, and distractive patterns and their effectiveness. However, work has almost exclusively focused on the efficacy of these strategies in preventing initial detection, despite the fact that predators often encounter the same prey phenotype repeatedly, affording them opportunities to learn to find those prey more effectively. The overall value of a camouflage strategy may, therefore, reflect both its ability to prevent detection by predators and resist predator learning. We conducted four experiments with humans searching for hidden targets of different camouflage types (disruptive, distractive, and background matching of various contrast levels over a series of touch screen trials. As with previous work, disruptive coloration was the most successful method of concealment overall, especially with relatively high contrast patterns, whereas potentially distractive markings were either neutral or costly. However, high contrast patterns incurred faster decreases in detection times over trials compared to other stimuli. In addition, potentially distractive markings were sometimes learnt more slowly than background matching markings, despite being found more readily overall. Finally, learning effects were highly dependent upon the experimental paradigm, including the number of prey types seen and whether subjects encountered targets simultaneously or sequentially. Our results show that the survival advantage of camouflage strategies reflects both their ability to avoid initial detection (sensory mechanisms and predator learning (perceptual mechanisms.

  1. Masked priming for the comparative evaluation of camouflage conspicuity.

    Science.gov (United States)

    Brunyé, Tad T; Eddy, Marianna D; Cain, Matthew S; Hepfinger, Lisa B; Rock, Kathryn

    2017-07-01

    Human observer test and evaluation of camouflage patterns is critical for understanding relative pattern conspicuity against a range of background scenes. However, very few validated methodologies exist for this purpose, and those that do carry several limitations. Five experiments examined whether masked priming with a dot probe could be used to reliably differentiate camouflage patterns. In each experiment, participants were primed with a camouflaged target appearing on the left or right of the screen, and then made a speeded response to a dot probe appearing on the same (congruent) or different (incongruent) side. Across experiments we parametrically varied prime duration between 35, 42, 49, 56, and 63 ms. Results demonstrated that as prime duration increased, a response time disadvantage for incongruent trials emerged with certain camouflage patterns. Interestingly, the most conspicuous patterns showed behavioral differences at a relatively brief (49 ms) prime duration, whereas behavioral differences were only found at longer prime durations for less conspicuous patterns; this overall results pattern matched that predicted by a visual salience model. Together, we demonstrate the viability of masked priming for the test and evaluation of camouflage patterns, and correlated outcomes for saliency models and primed object processing. Published by Elsevier Ltd.

  2. Contrast, contours and the confusion effect in dazzle camouflage.

    Science.gov (United States)

    Hogan, Benedict G; Scott-Samuel, Nicholas E; Cuthill, Innes C

    2016-07-01

    'Motion dazzle camouflage' is the name for the putative effects of highly conspicuous, often repetitive or complex, patterns on parameters important in prey capture, such as the perception of speed, direction and identity. Research into motion dazzle camouflage is increasing our understanding of the interactions between visual tracking, the confusion effect and defensive coloration. However, there is a paucity of research into the effects of contrast on motion dazzle camouflage: is maximal contrast a prerequisite for effectiveness? If not, this has important implications for our recognition of the phenotype and understanding of the function and mechanisms of potential motion dazzle camouflage patterns. Here we tested human participants' ability to track one moving target among many identical distractors with surface patterns designed to test the influence of these factors. In line with previous evidence, we found that targets with stripes parallel to the object direction of motion were hardest to track. However, reduction in contrast did not significantly influence this result. This finding may bring into question the utility of current definitions of motion dazzle camouflage, and means that some animal patterns, such as aposematic or mimetic stripes, may have previously unrecognized multiple functions.

  3. Defeating crypsis: detection and learning of camouflage strategies.

    Science.gov (United States)

    Troscianko, Jolyon; Lown, Alice E; Hughes, Anna E; Stevens, Martin

    2013-01-01

    Camouflage is perhaps the most widespread defence against predators in nature and an active area of interdisciplinary research. Recent work has aimed to understand what camouflage types exist (e.g. background matching, disruptive, and distractive patterns) and their effectiveness. However, work has almost exclusively focused on the efficacy of these strategies in preventing initial detection, despite the fact that predators often encounter the same prey phenotype repeatedly, affording them opportunities to learn to find those prey more effectively. The overall value of a camouflage strategy may, therefore, reflect both its ability to prevent detection by predators and resist predator learning. We conducted four experiments with humans searching for hidden targets of different camouflage types (disruptive, distractive, and background matching of various contrast levels) over a series of touch screen trials. As with previous work, disruptive coloration was the most successful method of concealment overall, especially with relatively high contrast patterns, whereas potentially distractive markings were either neutral or costly. However, high contrast patterns incurred faster decreases in detection times over trials compared to other stimuli. In addition, potentially distractive markings were sometimes learnt more slowly than background matching markings, despite being found more readily overall. Finally, learning effects were highly dependent upon the experimental paradigm, including the number of prey types seen and whether subjects encountered targets simultaneously or sequentially. Our results show that the survival advantage of camouflage strategies reflects both their ability to avoid initial detection (sensory mechanisms) and predator learning (perceptual mechanisms).

  4. Disruptive coloration in woodland camouflage: evaluation of camouflage effectiveness due to minor disruptive patches

    Science.gov (United States)

    Selj, Gorm K.; Heinrich, Daniela H.

    2016-10-01

    We present results from an observer based photosimulation study of generic camouflage patterns, intended for military uniforms, where three near-identical patterns have been compared. All the patterns were prepared with similar effective color, but were different in how the individual pattern patches were distributed throughout the target. We did this in order to test if high contrast (black) patches along the outline of the target would enhance the survivability when exposed to human observers. In the recent years it has been shown that disruptive coloration in the form of high contrast patches are capable of disturbing an observer by creating false edges of the target and consequently enhance target survivability. This effect has been shown in different forms in the Animal Kingdom, but not to the same extent in camouflaged military targets. The three patterns in this study were i) with no disruptive preference, ii) with a disruptive patch along the outline of the head and iii) with a disruptive patch on the outline of one of the shoulders. We used a high number of human observers to assess the three targets in 16 natural (woodland) backgrounds by showing images of one of the targets at the time on a high definition pc screen. We found that the two patterns that were thought to have a minor disruptive preference to the remaining pattern were more difficult to detect in some (though not all) of the 16 scenes and were also better in overall performance when all the scenes were accounted for.

  5. Research on measurement method of optical camouflage effect of moving object

    Science.gov (United States)

    Wang, Juntang; Xu, Weidong; Qu, Yang; Cui, Guangzhen

    2016-10-01

    Camouflage effectiveness measurement as an important part of the camouflage technology, which testing and measuring the camouflage effect of the target and the performance of the camouflage equipment according to the tactical and technical requirements. The camouflage effectiveness measurement of current optical band is mainly aimed at the static target which could not objectively reflect the dynamic camouflage effect of the moving target. This paper synthetical used technology of dynamic object detection and camouflage effect detection, the digital camouflage of the moving object as the research object, the adaptive background update algorithm of Surendra was improved, a method of optical camouflage effect detection using Lab-color space in the detection of moving-object was presented. The binary image of moving object is extracted by this measurement technology, in the sequence diagram, the characteristic parameters such as the degree of dispersion, eccentricity, complexity and moment invariants are constructed to construct the feature vector space. The Euclidean distance of moving target which through digital camouflage was calculated, the results show that the average Euclidean distance of 375 frames was 189.45, which indicated that the degree of dispersion, eccentricity, complexity and moment invariants of the digital camouflage graphics has a great difference with the moving target which not spray digital camouflage. The measurement results showed that the camouflage effect was good. Meanwhile with the performance evaluation module, the correlation coefficient of the dynamic target image range 0.1275 from 0.0035, and presented some ups and down. Under the dynamic condition, the adaptability of target and background was reflected. In view of the existing infrared camouflage technology, the next step, we want to carry out the camouflage effect measurement technology of the moving target based on infrared band.

  6. Transient experimental demonstration of an elliptical thermal camouflage device.

    Science.gov (United States)

    He, Xiao; Yang, Tianzhi; Zhang, Xingwei; Wu, Linzhi; He, Xiao Qiao

    2017-11-30

    The camouflage phenomenon (invisibility or illusion) of thermodynamics has attracted great attentions and many experimental demonstrations have been achieved by virtue of simplified approaches or the scattering cancellation. However, all of the experiments conducted are limited in the invisibility of spheres or two-dimensional (2D) cylinders. An ellipsoid camouflage device with a homogenous and isotropic shell is firstly reported based on the idea of the neutral inclusion and a 2D elliptical thermal camouflage device is realized by a thin-layer cloak of homogeneous isotropic material firstly. The robustness of this scheme is validated in both 2D and 3D configurations. The current work may provide a new avenue to the control of the thermal signatures and we believe this work will broaden the current research and pave a new path to the control of the path of the heat transfer.

  7. Camouflage target detection via hyperspectral imaging plus information divergence measurement

    Science.gov (United States)

    Chen, Yuheng; Chen, Xinhua; Zhou, Jiankang; Ji, Yiqun; Shen, Weimin

    2016-01-01

    Target detection is one of most important applications in remote sensing. Nowadays accurate camouflage target distinction is often resorted to spectral imaging technique due to its high-resolution spectral/spatial information acquisition ability as well as plenty of data processing methods. In this paper, hyper-spectral imaging technique together with spectral information divergence measure method is used to solve camouflage target detection problem. A self-developed visual-band hyper-spectral imaging device is adopted to collect data cubes of certain experimental scene before spectral information divergences are worked out so as to discriminate target camouflage and anomaly. Full-band information divergences are measured to evaluate target detection effect visually and quantitatively. Information divergence measurement is proved to be a low-cost and effective tool for target detection task and can be further developed to other target detection applications beyond spectral imaging technique.

  8. Habit persistence

    DEFF Research Database (Denmark)

    Vinther Møller, Stig

    2009-01-01

    This paper uses an iterated GMM approach to estimate and test the consumption based habit persistence model of Campbell and Cochrane (1999) on the US stock market. The empirical evidence shows that the model is able to explain the size premium, but fails to explain the value premium. Further...

  9. Planetary Habitability

    Science.gov (United States)

    Kasting, James F.

    1997-01-01

    This grant was entitled 'Planetary Habitability' and the work performed under it related to elucidating the conditions that lead to habitable, i.e. Earth-like, planets. Below are listed publications for the past two and a half years that came out of this work. The main thrusts of the research involved: (1) showing under what conditions atmospheric O2 and O3 can be considered as evidence for life on a planet's surface; (2) determining whether CH4 may have played a role in warming early Mars; (3) studying the effect of varying UV levels on Earth-like planets around different types of stars to see whether this would pose a threat to habitability; and (4) studying the effect of chaotic obliquity variations on planetary climates and determining whether planets that experienced such variations might still be habitable. Several of these topics involve ongoing research that has been carried out under a new grant number, but which continues to be funded by NASA's Exobiology program.

  10. Pixelated camouflage patterns from the perspective of hyperspectral imaging

    Science.gov (United States)

    Racek, František; Jobánek, Adam; Baláž, Teodor; Krejčí, Jaroslav

    2016-10-01

    Pixelated camouflage patterns fulfill the role of both principles the matching and the disrupting that are exploited for blending the target into the background. It means that pixelated pattern should respect natural background in spectral and spatial characteristics embodied in micro and macro patterns. The HS imaging plays the similar, however the reverse role in the field of reconnaissance systems. The HS camera fundamentally records and extracts both the spectral and spatial information belonging to the recorded scenery. Therefore, the article deals with problems of hyperspectral (HS) imaging and subsequent processing of HS images of pixelated camouflage patterns which are among others characterized by their specific spatial frequency heterogeneity.

  11. Analysis and research on thermal infrared properties and adaptability of the camouflage net

    Science.gov (United States)

    Cui, Guangzhen; Hu, Jianghua; Jian, Chaochao; Yang, Juntang

    2016-10-01

    As camouflage equipment, camouflage net which covers or obstruct the enemy reconnaissance and attack, have the compatibility such as optics, infrared, radar wave band performance. To improve the adaptive between the camouflage net with background in infrared wavelengths, the heat shield and heat integration requirements on the surface of the camouflage net was analyzed. The condition that satisfied the heat shield was when the average thermal infrared transmittance was less than 25.38% on camouflage screen surface. Studies have shown that camouflage nets and the background field fused together when infrared radiation temperature difference control is within the scope of ± 4K . Experiment on temperature contrast was tested in situ background, thermal camouflage spots and camouflage net with sponge material, the infrared heat maps was recorded in the period of experiment through the thermal imager. Results showed that the thermal inertia of camouflage net was markedly lower than the background and the exposed signs were obvious. It was difficult to reach camouflage thermal infrared fusion requirements by relying on camouflage spot emissivity, but sponge which mix with polymer resin can reduce target significance in the context of mottled and realize the fusion effect.

  12. Maternal influence on eggshell maculation: implications for cryptic camouflaged eggs

    Czech Academy of Sciences Publication Activity Database

    Duval, C.; Cassey, P.; Lovell, P.G.; Mikšík, Ivan; Reynolds, S.J.; Spencer, K.A.

    2016-01-01

    Roč. 157, č. 1 (2016), s. 303-310 ISSN 0021-8375 R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:67985823 Keywords : body condition * camouflage * Coturnix coturnix japonica * eggs hell maculation * Protoporphyrin Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.468, year: 2016

  13. Image feature extraction based on the camouflage effectiveness evaluation

    Science.gov (United States)

    Yuan, Xin; Lv, Xuliang; Li, Ling; Wang, Xinzhu; Zhang, Zhi

    2018-04-01

    The key step of camouflage effectiveness evaluation is how to combine the human visual physiological features, psychological features to select effectively evaluation indexes. Based on the predecessors' camo comprehensive evaluation method, this paper chooses the suitable indexes combining with the image quality awareness, and optimizes those indexes combining with human subjective perception. Thus, it perfects the theory of index extraction.

  14. Quantifying camouflage: how to predict detectability from appearance.

    Science.gov (United States)

    Troscianko, Jolyon; Skelhorn, John; Stevens, Martin

    2017-01-06

    Quantifying the conspicuousness of objects against particular backgrounds is key to understanding the evolution and adaptive value of animal coloration, and in designing effective camouflage. Quantifying detectability can reveal how colour patterns affect survival, how animals' appearances influence habitat preferences, and how receiver visual systems work. Advances in calibrated digital imaging are enabling the capture of objective visual information, but it remains unclear which methods are best for measuring detectability. Numerous descriptions and models of appearance have been used to infer the detectability of animals, but these models are rarely empirically validated or directly compared to one another. We compared the performance of human 'predators' to a bank of contemporary methods for quantifying the appearance of camouflaged prey. Background matching was assessed using several established methods, including sophisticated feature-based pattern analysis, granularity approaches and a range of luminance and contrast difference measures. Disruptive coloration is a further camouflage strategy where high contrast patterns disrupt they prey's tell-tale outline, making it more difficult to detect. Disruptive camouflage has been studied intensely over the past decade, yet defining and measuring it have proven far more problematic. We assessed how well existing disruptive coloration measures predicted capture times. Additionally, we developed a new method for measuring edge disruption based on an understanding of sensory processing and the way in which false edges are thought to interfere with animal outlines. Our novel measure of disruptive coloration was the best predictor of capture times overall, highlighting the importance of false edges in concealment over and above pattern or luminance matching. The efficacy of our new method for measuring disruptive camouflage together with its biological plausibility and computational efficiency represents a substantial

  15. Vertical visual features have a strong influence on cuttlefish camouflage.

    Science.gov (United States)

    Ulmer, K M; Buresch, K C; Kossodo, M M; Mäthger, L M; Siemann, L A; Hanlon, R T

    2013-04-01

    Cuttlefish and other cephalopods use visual cues from their surroundings to adaptively change their body pattern for camouflage. Numerous previous experiments have demonstrated the influence of two-dimensional (2D) substrates (e.g., sand and gravel habitats) on camouflage, yet many marine habitats have varied three-dimensional (3D) structures among which cuttlefish camouflage from predators, including benthic predators that view cuttlefish horizontally against such 3D backgrounds. We conducted laboratory experiments, using Sepia officinalis, to test the relative influence of horizontal versus vertical visual cues on cuttlefish camouflage: 2D patterns on benthic substrates were tested versus 2D wall patterns and 3D objects with patterns. Specifically, we investigated the influence of (i) quantity and (ii) placement of high-contrast elements on a 3D object or a 2D wall, as well as (iii) the diameter and (iv) number of 3D objects with high-contrast elements on cuttlefish body pattern expression. Additionally, we tested the influence of high-contrast visual stimuli covering the entire 2D benthic substrate versus the entire 2D wall. In all experiments, visual cues presented in the vertical plane evoked the strongest body pattern response in cuttlefish. These experiments support field observations that, in some marine habitats, cuttlefish will respond to vertically oriented background features even when the preponderance of visual information in their field of view seems to be from the 2D surrounding substrate. Such choices highlight the selective decision-making that occurs in cephalopods with their adaptive camouflage capability.

  16. Mating and Memory

    Directory of Open Access Journals (Sweden)

    Michael D. Baker

    2015-12-01

    Full Text Available The literature on sexual selection and the social brain hypothesis suggest that human cognition and communication evolved, in part, for the purpose of displaying desirable cognitive abilities to potential mates. An evolutionary approach to social cognition implies that proximate mating motives may lead people to display desirable mental traits. In signaling such traits, one can increase the likelihood of attracting a potential mate. Two experiments demonstrated that exposure to mating cues—highly attractive opposite-sex faces—led people to display enhancements in declarative memory—a process underlying a variety of abilities such as resource acquisition, intelligence, and creativity. Experiment 1 showed that men (but not women displayed enhanced memory for details of a story that was presented during exposure to highly attractive opposite-sex faces. Experiment 2 demonstrated that heightened displays of declarative memory reflect an enhancement in retrieval rather than in encoding. Findings contribute to the literatures on human mating and cognitive performance and provide novel insight into links between social processes and basic cognition.

  17. Exoplanet habitability.

    Science.gov (United States)

    Seager, Sara

    2013-05-03

    The search for exoplanets includes the promise to eventually find and identify habitable worlds. The thousands of known exoplanets and planet candidates are extremely diverse in terms of their masses or sizes, orbits, and host star type. The diversity extends to new kinds of planets, which are very common yet have no solar system counterparts. Even with the requirement that a planet's surface temperature must be compatible with liquid water (because all life on Earth requires liquid water), a new emerging view is that planets very different from Earth may have the right conditions for life. The broadened possibilities will increase the future chances of discovering an inhabited world.

  18. Sex roles and mutual mate choice matter during mate sampling.

    Science.gov (United States)

    Myhre, Lise Cats; de Jong, Karen; Forsgren, Elisabet; Amundsen, Trond

    2012-06-01

    The roles of females and males in mating competition and mate choice have lately proven more variable, between and within species, than previously thought. In nature, mating competition occurs during mate search and is expected to be regulated by the numbers of potential mates and same-sex competitors. Here, we present the first study to test how a temporal change in sex roles affects mating competition and mate choice during mate sampling. Our model system (the marine fish Gobiusculus flavescens) is uniquely suitable because of its change in sex roles, from conventional to reversed, over the breeding season. As predicted from sex role theory, courtship was typically initiated by males and terminated by females early in the breeding season. The opposite pattern was observed late in the season, at which time several females often simultaneously courted the same male. Mate-searching females visited more males early than late in the breeding season. Our study shows that mutual mate choice and mating competition can have profound effects on female and male behavior. Future work needs to consider the dynamic nature of mating competition and mate choice if we aim to fully understand sexual selection in the wild.

  19. Effectiveness estimation of camouflage measures with solar radiation and longwave radiation considered

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.S. [LG Electronics Corporation (Korea); Kauh, S.K. [Seoul National University, Seoul (Korea); Yoo, H.S. [Soongsil University, Seoul (Korea)

    1998-11-01

    Camouflage measures in military purpose utilizes the apparent temperature difference between the target and background, so it is essential to develop thermal analysis program for apparent temperature predictions and to apply some camouflage measures to real military targets for camouflage purpose. In this study, a thermal analysis program including conduction, convection and radiation is developed and the validity of radiation heat transfer terms is examined. The results show that longwave radiation along with solar radiation should be included in order to predict apparent temperature as well as physical temperature exactly. Longwave emissivity variation as an effective camouflage measures is applied to a real M2 tank. From the simulation results, it is found that an effective surface treatment, such as painting of a less emissive material or camouflage, clothing, may provide a temperature similarity or a spatial similarity, resulting in an effective camouflage. (author). 12 refs., 6 figs., 1 tab.

  20. SynchroMate

    DEFF Research Database (Denmark)

    Gibbs, M.; Vetere, F.; Bunyan, M

    2005-01-01

    ideas concerning technologies to support phatic interaction. Using the materials collected during our fieldwork as design inspirations, we developed design sketches for phatic technologies intended to support playful connection between intimates. One of these sketches – SynchroMate – is presented...

  1. Distress about mating rivals

    NARCIS (Netherlands)

    Buss, DM; Shackelford, TK; Choe, J; Buunk, BP; Dijkstra, P

    This research tested the evolutionary psychological hypothesis that men and women would be most distressed about threats from rivals who surpass them on sex-linked components of mate value. Six predictions were tested in samples from three cultures, the United States (N = 208), the Netherlands (N =

  2. Edge enhancement improves disruptive camouflage by emphasising false edges and creating pictorial relief.

    Science.gov (United States)

    Egan, John; Sharman, Rebecca J; Scott-Brown, Kenneth C; Lovell, Paul George

    2016-12-06

    Disruptive colouration is a visual camouflage composed of false edges and boundaries. Many disruptively camouflaged animals feature enhanced edges; light patches are surrounded by a lighter outline and/or a dark patches are surrounded by a darker outline. This camouflage is particularly common in amphibians, reptiles and lepidopterans. We explored the role that this pattern has in creating effective camouflage. In a visual search task utilising an ultra-large display area mimicking search tasks that might be found in nature, edge enhanced disruptive camouflage increases crypsis, even on substrates that do not provide an obvious visual match. Specifically, edge enhanced camouflage is effective on backgrounds both with and without shadows; i.e. this is not solely due to background matching of the dark edge enhancement element with the shadows. Furthermore, when the dark component of the edge enhancement is omitted the camouflage still provided better crypsis than control patterns without edge enhancement. This kind of edge enhancement improved camouflage on all background types. Lastly, we show that edge enhancement can create a perception of multiple surfaces. We conclude that edge enhancement increases the effectiveness of disruptive camouflage through mechanisms that may include the improved disruption of the object outline by implying pictorial relief.

  3. Breaking cover: neural responses to slow and fast camouflage-breaking motion.

    Science.gov (United States)

    Yin, Jiapeng; Gong, Hongliang; An, Xu; Chen, Zheyuan; Lu, Yiliang; Andolina, Ian M; McLoughlin, Niall; Wang, Wei

    2015-08-22

    Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate visual brain? We investigated this question using intrinsic-signal optical imaging of macaque V1, V2 and V4, along with computer simulations of the neural population responses. We found that camouflaged motion at low speed was processed as a direction signal by both direction- and orientation-selective neurons, whereas at high-speed camouflaged motion was encoded as a motion-streak signal primarily by orientation-selective neurons. No population responses were found to be invariant to the camouflage contours. These results suggest that the initial processing of camouflaged motion at low and high speeds is encoded as direction and motion-streak signals in primate early visual cortices. These processes are consistent with a spatio-temporal filter mechanism that provides for fast processing of motion signals, prior to full recognition of camouflage-breaking animals. © 2015 The Authors.

  4. Three-dimensional illusion thermal device for location camouflage.

    Science.gov (United States)

    Wang, Jing; Bi, Yanqiang; Hou, Quanwen

    2017-08-08

    Thermal metamaterials, proposed in recent years, provide a new method to manipulate the energy flux in heat transfer, and result in many novel thermal devices. In this paper, an illusion thermal device for location camouflage in 3-dimensional heat conduction regime is proposed based on the transformation thermodynamics. The heat source covered by the device produces a fake signal outside the device, which makes the source look like appearing at another position away from its real position. The parameters required by the device are deduced and the method is validated by simulations. The possible scheme to obtain the thermal conductivities required in the device by composing natural materials is supplied, and the influence of some problems in practical fabrication process of the device on the effect of the camouflage is also discussed.

  5. CONTEMPORARY DESIGN CONCEPTS IN CAMOUFLAGE: UNIVERSAL VERSUS SPECIALIZED

    Directory of Open Access Journals (Sweden)

    TACHEV Momchil

    2015-06-01

    Full Text Available In present days there is a strong influence of the concept incorporating increased use of low intensive colours and small “digitalized” form structures for modern army camouflage designs. It was proclaimed as a revolutionary “universal” design line. It was supposed to be superior to others patterns designs and to be optimal for most types of environment. Meanwhile, some arm forces insist on developing more limited as terrain range camouflage design but with better efficiency and specialization. These two concepts in design reflect the political and the military philosophies of the countries they represent. However, at the end for the soldiers at the battlefield it is a matter of survival.

  6. Biomimetic chromatophores for camouflage and soft active surfaces

    International Nuclear Information System (INIS)

    Rossiter, Jonathan; Yap, Bryan; Conn, Andrew

    2012-01-01

    Chromatophores are the pigment-containing cells in the skins of animals such as fish and cephalopods which have chromomorphic (colour-changing) and controllable goniochromic (iridescent-changing) properties. These animals control the optical properties of their skins for camouflage and, it is speculated, for communication. The ability to replicate these properties in soft artificial skin structures opens up new possibilities for active camouflage, thermal regulation and active photovoltaics. This paper presents the design and implementation of soft and compliant artificial chromatophores based on the cutaneous chromatophores in fish and cephalopods. We demonstrate artificial chromatophores that are actuated by electroactive polymer artificial muscles, mimicking the radially orientated muscles found in natural chromatophores. It is shown how bio-inspired chromomorphism may be achieved using both areal expansion of dielectric elastomer structures and by the hydrostatic translocation of pigmented fluid into an artificial dermal melanophore. (paper)

  7. High fitness costs of climate change-induced camouflage mismatch.

    Science.gov (United States)

    Zimova, Marketa; Mills, L Scott; Nowak, J Joshua

    2016-03-01

    Anthropogenic climate change has created myriad stressors that threaten to cause local extinctions if wild populations fail to adapt to novel conditions. We studied individual and population-level fitness costs of a climate change-induced stressor: camouflage mismatch in seasonally colour molting species confronting decreasing snow cover duration. Based on field measurements of radiocollared snowshoe hares, we found strong selection on coat colour molt phenology, such that animals mismatched with the colour of their background experienced weekly survival decreases up to 7%. In the absence of adaptive response, we show that these mortality costs would result in strong population-level declines by the end of the century. However, natural selection acting on wide individual variation in molt phenology might enable evolutionary adaptation to camouflage mismatch. We conclude that evolutionary rescue will be critical for hares and other colour molting species to keep up with climate change. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  8. Female fitness optimum at intermediate mating rates under traumatic mating.

    Directory of Open Access Journals (Sweden)

    Rolanda Lange

    Full Text Available Traumatic mating behaviors often bear signatures of sexual conflict and are then typically considered a male strategy to circumvent female choice mechanisms. In an extravagant mating ritual, the hermaphroditic sea slug Siphopteron quadrispinosum pierces the integument of their mating partners with a syringe-like penile stylet that injects prostate fluids. Traumatic injection is followed by the insertion of a spiny penis into the partner's gonopore to transfer sperm. Despite traumatic mating, field mating rates exceed those required for female fertilization insurance, possibly because costs imposed on females are balanced by direct or indirect benefits of multiple sperm receipt. To test this idea, we exposed animals to a relevant range of mating opportunity regimes and assessed the effects on mating behavior and proxies of female fitness. We find penis intromission duration to decrease with mating rates, and a female fecundity maximum at intermediate mating rates. The latter finding indicates that benefits beyond fertilization insurance can make higher mating rates also beneficial from a female perspective in this traumatically mating species.

  9. Debris-carrying camouflage among diverse lineages of Cretaceous insects.

    Science.gov (United States)

    Wang, Bo; Xia, Fangyuan; Engel, Michael S; Perrichot, Vincent; Shi, Gongle; Zhang, Haichun; Chen, Jun; Jarzembowski, Edmund A; Wappler, Torsten; Rust, Jes

    2016-06-01

    Insects have evolved diverse methods of camouflage that have played an important role in their evolutionary success. Debris-carrying, a behavior of actively harvesting and carrying exogenous materials, is among the most fascinating and complex behaviors because it requires not only an ability to recognize, collect, and carry materials but also evolutionary adaptations in related morphological characteristics. However, the fossil record of such behavior is extremely scarce, and only a single Mesozoic example from Spanish amber has been recorded; therefore, little is known about the early evolution of this complicated behavior and its underlying anatomy. We report a diverse insect assemblage of exceptionally preserved debris carriers from Cretaceous Burmese, French, and Lebanese ambers, including the earliest known chrysopoid larvae (green lacewings), myrmeleontoid larvae (split-footed lacewings and owlflies), and reduviids (assassin bugs). These ancient insects used a variety of debris material, including insect exoskeletons, sand grains, soil dust, leaf trichomes of gleicheniacean ferns, wood fibers, and other vegetal debris. They convergently evolved their debris-carrying behavior through multiple pathways, which expressed a high degree of evolutionary plasticity. We demonstrate that the behavioral repertoire, which is associated with considerable morphological adaptations, was already widespread among insects by at least the Mid-Cretaceous. Together with the previously known Spanish specimen, these fossils are the oldest direct evidence of camouflaging behavior in the fossil record. Our findings provide a novel insight into early evolution of camouflage in insects and ancient ecological associations among plants and insects.

  10. Dazzle camouflage, target tracking, and the confusion effect.

    Science.gov (United States)

    Hogan, Benedict G; Cuthill, Innes C; Scott-Samuel, Nicholas E

    2016-01-01

    The influence of coloration on the ecology and evolution of moving animals in groups is poorly understood. Animals in groups benefit from the "confusion effect," where predator attack success is reduced with increasing group size or density. This is thought to be due to a sensory bottleneck: an increase in the difficulty of tracking one object among many. Motion dazzle camouflage has been hypothesized to disrupt accurate perception of the trajectory or speed of an object or animal. The current study investigates the suggestion that dazzle camouflage may enhance the confusion effect. Utilizing a computer game style experiment with human predators, we found that when moving in groups, targets with stripes parallel to the targets' direction of motion interact with the confusion effect to a greater degree, and are harder to track, than those with more conventional background matching patterns. The findings represent empirical evidence that some high-contrast patterns may benefit animals in groups. The results also highlight the possibility that orientation and turning may be more relevant in the mechanisms of dazzle camouflage than previously recognized.

  11. Improvement of individual camouflage through background choice in ground-nesting birds

    Science.gov (United States)

    Stevens, Martin; Troscianko, Jolyon; Wilson-Aggarwal, Jared K.; Spottiswoode, Claire N.

    2017-01-01

    Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales. PMID:28890937

  12. Cuttlefish dynamic camouflage: responses to substrate choice and integration of multiple visual cues.

    Science.gov (United States)

    Allen, Justine J; Mäthger, Lydia M; Barbosa, Alexandra; Buresch, Kendra C; Sogin, Emilia; Schwartz, Jillian; Chubb, Charles; Hanlon, Roger T

    2010-04-07

    Prey camouflage is an evolutionary response to predation pressure. Cephalopods have extensive camouflage capabilities and studying them can offer insight into effective camouflage design. Here, we examine whether cuttlefish, Sepia officinalis, show substrate or camouflage pattern preferences. In the first two experiments, cuttlefish were presented with a choice between different artificial substrates or between different natural substrates. First, the ability of cuttlefish to show substrate preference on artificial and natural substrates was established. Next, cuttlefish were offered substrates known to evoke three main camouflage body pattern types these animals show: Uniform or Mottle (function by background matching); or Disruptive. In a third experiment, cuttlefish were presented with conflicting visual cues on their left and right sides to assess their camouflage response. Given a choice between substrates they might encounter in nature, we found no strong substrate preference except when cuttlefish could bury themselves. Additionally, cuttlefish responded to conflicting visual cues with mixed body patterns in both the substrate preference and split substrate experiments. These results suggest that differences in energy costs for different camouflage body patterns may be minor and that pattern mixing and symmetry may play important roles in camouflage.

  13. Developing and evaluating a target-background similarity metric for camouflage detection.

    Directory of Open Access Journals (Sweden)

    Chiuhsiang Joe Lin

    Full Text Available BACKGROUND: Measurement of camouflage performance is of fundamental importance for military stealth applications. The goal of camouflage assessment algorithms is to automatically assess the effect of camouflage in agreement with human detection responses. In a previous study, we found that the Universal Image Quality Index (UIQI correlated well with the psychophysical measures, and it could be a potentially camouflage assessment tool. METHODOLOGY: In this study, we want to quantify the camouflage similarity index and psychophysical results. We compare several image quality indexes for computational evaluation of camouflage effectiveness, and present the results of an extensive human visual experiment conducted to evaluate the performance of several camouflage assessment algorithms and analyze the strengths and weaknesses of these algorithms. SIGNIFICANCE: The experimental data demonstrates the effectiveness of the approach, and the correlation coefficient result of the UIQI was higher than those of other methods. This approach was highly correlated with the human target-searching results. It also showed that this method is an objective and effective camouflage performance evaluation method because it considers the human visual system and image structure, which makes it consistent with the subjective evaluation results.

  14. Improvement of individual camouflage through background choice in ground-nesting birds.

    Science.gov (United States)

    Stevens, Martin; Troscianko, Jolyon; Wilson-Aggarwal, Jared K; Spottiswoode, Claire N

    2017-09-01

    Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales.

  15. Social Camouflage: Interpreting Male Student Veterans' Behavior for Residence Life Professionals

    Science.gov (United States)

    Livingston, Wade G.; Scott, David A.; Havice, Pamela A.; Cawthon, Tony W.

    2012-01-01

    The term "camouflage" implies obscurity and concealment. Male student veterans who return from the military often employ a social camouflage; though some may reveal and discuss their military experience, their overriding objective is to blend in, have a "normal" college experience, and graduate. This creates challenges for housing professionals…

  16. Developing and evaluating a target-background similarity metric for camouflage detection.

    Science.gov (United States)

    Lin, Chiuhsiang Joe; Chang, Chi-Chan; Liu, Bor-Shong

    2014-01-01

    Measurement of camouflage performance is of fundamental importance for military stealth applications. The goal of camouflage assessment algorithms is to automatically assess the effect of camouflage in agreement with human detection responses. In a previous study, we found that the Universal Image Quality Index (UIQI) correlated well with the psychophysical measures, and it could be a potentially camouflage assessment tool. In this study, we want to quantify the camouflage similarity index and psychophysical results. We compare several image quality indexes for computational evaluation of camouflage effectiveness, and present the results of an extensive human visual experiment conducted to evaluate the performance of several camouflage assessment algorithms and analyze the strengths and weaknesses of these algorithms. The experimental data demonstrates the effectiveness of the approach, and the correlation coefficient result of the UIQI was higher than those of other methods. This approach was highly correlated with the human target-searching results. It also showed that this method is an objective and effective camouflage performance evaluation method because it considers the human visual system and image structure, which makes it consistent with the subjective evaluation results.

  17. Background matching and camouflage efficiency predict population density in four-eyed turtle (Sacalia quadriocellata).

    Science.gov (United States)

    Xiao, Fanrong; Yang, Canchao; Shi, Haitao; Wang, Jichao; Sun, Liang; Lin, Liu

    2016-10-01

    Background matching is an important way to camouflage and is widespread among animals. In the field, however, few studies have addressed background matching, and there has been no reported camouflage efficiency in freshwater turtles. Background matching and camouflage efficiency of the four-eyed turtle, Sacalia quadriocellata, among three microhabitat sections of Hezonggou stream were investigated by measuring carapace components of CIE L*a*b* (International Commission on Illumination; lightness, red/green and yellow/blue) color space, and scoring camouflage efficiency through the use of humans as predators. The results showed that the color difference (ΔE), lightness difference (ΔL(*)), and chroma difference (Δa(*)b(*)) between carapace and the substrate background in midstream were significantly lower than that upstream and downstream, indicating that the four-eyed turtle carapace color most closely matched the substrate of midstream. In line with these findings, the camouflage efficiency was the best for the turtles that inhabit midstream. These results suggest that the four-eyed turtles may enhance camouflage efficiency by selecting microhabitat that best match their carapace color. This finding may explain the high population density of the four-eyed turtle in the midstream section of Hezonggou stream. To the best of our knowledge, this study is among the first to quantify camouflage of freshwater turtles in the wild, laying the groundwork to further study the function and mechanisms of turtle camouflage. Copyright © 2016. Published by Elsevier B.V.

  18. Breaking camouflage and detecting targets require optic flow and image structure information.

    Science.gov (United States)

    Pan, Jing Samantha; Bingham, Ned; Chen, Chang; Bingham, Geoffrey P

    2017-08-01

    Use of motion to break camouflage extends back to the Cambrian [In the Blink of an Eye: How Vision Sparked the Big Bang of Evolution (New York Basic Books, 2003)]. We investigated the ability to break camouflage and continue to see camouflaged targets after motion stops. This is crucial for the survival of hunting predators. With camouflage, visual targets and distracters cannot be distinguished using only static image structure (i.e., appearance). Motion generates another source of optical information, optic flow, which breaks camouflage and specifies target locations. Optic flow calibrates image structure with respect to spatial relations among targets and distracters, and calibrated image structure makes previously camouflaged targets perceptible in a temporally stable fashion after motion stops. We investigated this proposal using laboratory experiments and compared how many camouflaged targets were identified either with optic flow information alone or with combined optic flow and image structure information. Our results show that the combination of motion-generated optic flow and target-projected image structure information yielded efficient and stable perception of camouflaged targets.

  19. Efficient Breeding by Genomic Mating.

    Science.gov (United States)

    Akdemir, Deniz; Sánchez, Julio I

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

  20. An optimal control strategy for two-dimensional motion camouflage with non-holonimic constraints.

    Science.gov (United States)

    Rañó, Iñaki

    2012-07-01

    Motion camouflage is a stealth behaviour observed both in hover-flies and in dragonflies. Existing controllers for mimicking motion camouflage generate this behaviour on an empirical basis or without considering the kinematic motion restrictions present in animal trajectories. This study summarises our formal contributions to solve the generation of motion camouflage as a non-linear optimal control problem. The dynamics of the system capture the kinematic restrictions to motion of the agents, while the performance index ensures camouflage trajectories. An extensive set of simulations support the technique, and a novel analysis of the obtained trajectories contributes to our understanding of possible mechanisms to obtain sensor based motion camouflage, for instance, in mobile robots.

  1. Class III camouflage treatment: what are the limits?

    Science.gov (United States)

    Burns, Nikia R; Musich, David R; Martin, Chris; Razmus, Thomas; Gunel, Erdogan; Ngan, Peter

    2010-01-01

    The purpose of this study was to determine the skeletal, dental, and soft-tissue changes in response to camouflage Class III treatment. Thirty patients (average age, 12.4 + or - 1.0 years) with skeletal Class III malocclusions who completed comprehensive nonextraction orthodontic treatment were studied. Skeletal, dental, and soft-tissue changes were determined by using published cephalometric analyses. The quality of orthodontic treatment was standardized by registering the peer assessment rating index on the pretreatment and posttreatment study models. The change in the level of gingival attachment with treatment was determined on the study casts. The results were compared with a group of untreated subjects. Data were analyzed with repeated measures analysis and paired t tests. The average change in the Wits appraisal was greater in the treated group (1.2 + or - 0.1 mm) than in the control group (-0.5 + or - 0.3 mm). The average peer assessment rating index score improved from 33.5 to 4.1. No significant differences were found for the level of gingival attachments between the treatment and control groups. The sagittal jaw relationship (ANB angle) did not improve with camouflage treatment. A wide range of tooth movements compensated for the skeletal changes in both groups. The upper and lower limits for incisal movement to compensate for Class III skeletal changes were 120 degrees to the sella-nasion line and 80 degrees to the mandibular plane, respectively. Greater increases in the angle of convexity were found in the treated group, indicating improved facial profiles. Greater increases in length of the upper lip were found in the treated group, corresponding to the changes in the hard tissues with treatment. Significant dental and soft-tissue changes can be expected in young Class III patients treated with camouflage orthodontic tooth movement. A wide range of skeletal dysplasias can be camouflaged with tooth movement without deleterious effects to the

  2. Training and transfer of training in rapid visual search for camouflaged targets.

    Directory of Open Access Journals (Sweden)

    Mark B Neider

    Full Text Available Previous examinations of search under camouflage conditions have reported that performance improves with training and that training can engender near perfect transfer to similar, but novel camouflage-type displays [1]. What remains unclear, however, are the cognitive mechanisms underlying these training improvements and transfer benefits. On the one hand, improvements and transfer benefits might be associated with higher-level overt strategy shifts, such as through the restriction of eye movements to target-likely (background display regions. On the other hand, improvements and benefits might be related to the tuning of lower-level perceptual processes, such as figure-ground segregation. To decouple these competing possibilities we had one group of participants train on camouflage search displays and a control group train on non-camouflage displays. Critically, search displays were rapidly presented, precluding eye movements. Before and following training, all participants completed transfer sessions in which they searched novel displays. We found that search performance on camouflage displays improved with training. Furthermore, participants who trained on camouflage displays suffered no performance costs when searching novel displays following training. Our findings suggest that training to break camouflage is related to the tuning of perceptual mechanisms and not strategic shifts in overt attention.

  3. Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators.

    Science.gov (United States)

    Chiao, Chuan-Chin; Wickiser, J Kenneth; Allen, Justine J; Genter, Brock; Hanlon, Roger T

    2011-05-31

    Camouflage is a widespread phenomenon throughout nature and an important antipredator tactic in natural selection. Many visual predators have keen color perception, and thus camouflage patterns should provide some degree of color matching in addition to other visual factors such as pattern, contrast, and texture. Quantifying camouflage effectiveness in the eyes of the predator is a challenge from the perspectives of both biology and optical imaging technology. Here we take advantage of hyperspectral imaging (HSI), which records full-spectrum light data, to simultaneously visualize color match and pattern match in the spectral and the spatial domains, respectively. Cuttlefish can dynamically camouflage themselves on any natural substrate and, despite their colorblindness, produce body patterns that appear to have high-fidelity color matches to the substrate when viewed directly by humans or with RGB images. Live camouflaged cuttlefish on natural backgrounds were imaged using HSI, and subsequent spectral analysis revealed that most reflectance spectra of individual cuttlefish and substrates were similar, rendering the color match possible. Modeling color vision of potential di- and trichromatic fish predators of cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged cuttlefish show good color match as well as pattern match in the eyes of fish predators. These findings (i) indicate the strong potential of HSI technology to enhance studies of biological coloration and (ii) provide supporting evidence that cuttlefish can produce color-coordinated camouflage on natural substrates despite lacking color vision.

  4. The dual function of barred plumage in birds: camouflage and communication.

    Science.gov (United States)

    Gluckman, T L; Cardoso, G C

    2010-11-01

    A commonly held principle in visual ecology is that communication compromises camouflage: while visual signals are often conspicuous, camouflage provides concealment. However, some traits may have evolved for communication and camouflage simultaneously, thereby overcoming this functional compromise. Visual patterns generally provide camouflage, but it was suggested that a particular type of visual pattern – avian barred plumage – could also be a signal of individual quality. Here, we test if the evolution of sexual dimorphism in barred plumage, as well as differences between juvenile and adult plumage, indicate camouflage and/or signalling functions across the class Aves. We found a higher frequency of female- rather than male-biased sexual dimorphism in barred plumage, indicating that camouflage is its most common function. But we also found that, compared to other pigmentation patterns, barred plumage is more frequently biased towards males and its expression more frequently restricted to adulthood, suggesting that barred plumage often evolves or is maintained as a sexual communication signal. This illustrates how visual traits can accommodate the apparently incompatible functions of camouflage and communication, which has implications for our understanding of avian visual ecology and sexual ornamentation.

  5. Experimental Evaluation of Camouflage Effectiveness in the Thermal Infrared (Experimentele Evaluatie van de Effectiviteit van Camouflage in het Thermische Infrarood)

    Science.gov (United States)

    1993-03-01

    shape distortion. For recognitio , , however, camouflage rnr’f.ure" have to adjiist the tLugek signoawuie in more detail to the background clutter...ous trees, 4m height at ±100m range 4 ag.. _!tural field (seasonal plant growing) 5 ba~e soil (ploughed rough surface) 1) concrete -, face 7 Water...surlace (small pond, Im depth) 8 Up- and down hill slopes (bare seil and grass covered). North and South facing At regular intervals, the physical

  6. Distance-dependent pattern blending can camouflage salient aposematic signals.

    Science.gov (United States)

    Barnett, James B; Cuthill, Innes C; Scott-Samuel, Nicholas E

    2017-07-12

    The effect of viewing distance on the perception of visual texture is well known: spatial frequencies higher than the resolution limit of an observer's visual system will be summed and perceived as a single combined colour. In animal defensive colour patterns, distance-dependent pattern blending may allow aposematic patterns, salient at close range, to match the background to distant observers. Indeed, recent research has indicated that reducing the distance from which a salient signal can be detected can increase survival over camouflage or conspicuous aposematism alone. We investigated whether the spatial frequency of conspicuous and cryptically coloured stripes affects the rate of avian predation. Our results are consistent with pattern blending acting to camouflage salient aposematic signals effectively at a distance. Experiments into the relative rate of avian predation on edible model caterpillars found that increasing spatial frequency (thinner stripes) increased survival. Similarly, visual modelling of avian predators showed that pattern blending increased the similarity between caterpillar and background. These results show how a colour pattern can be tuned to reveal or conceal different information at different distances, and produce tangible survival benefits. © 2017 The Author(s).

  7. Repeated evolution of camouflage in speciose desert rodents.

    Science.gov (United States)

    Boratyński, Zbyszek; Brito, José C; Campos, João C; Cunha, José L; Granjon, Laurent; Mappes, Tapio; Ndiaye, Arame; Rzebik-Kowalska, Barbara; Serén, Nina

    2017-06-14

    There are two main factors explaining variation among species and the evolution of characters along phylogeny: adaptive change, including phenotypic and genetic responses to selective pressures, and phylogenetic inertia, or the resemblance between species due to shared phylogenetic history. Phenotype-habitat colour match, a classic Darwinian example of the evolution of camouflage (crypsis), offers the opportunity to test the importance of historical versus ecological mechanisms in shaping phenotypes among phylogenetically closely related taxa. To assess it, we investigated fur (phenotypic data) and habitat (remote sensing data) colourations, along with phylogenetic information, in the species-rich Gerbillus genus. Overall, we found a strong phenotype-habitat match, once the phylogenetic signal is taken into account. We found that camouflage has been acquired and lost repeatedly in the course of the evolutionary history of Gerbillus. Our results suggest that fur colouration and its covariation with habitat is a relatively labile character in mammals, potentially responding quickly to selection. Relatively unconstrained and substantial genetic basis, as well as structural and functional independence from other fitness traits of mammalian colouration might be responsible for that observation.

  8. Shade determination using camouflaged visual shade guides and an electronic spectrophotometer.

    Science.gov (United States)

    Kvalheim, S F; Øilo, M

    2014-03-01

    The aim of the present study was to compare a camouflaged visual shade guide to a spectrophotometer designed for restorative dentistry. Two operators performed analyses of 66 subjects. One central upper incisor was measured four times by each operator; twice with a camouflaged visual shade guide and twice with a spectrophotometer Both methods had acceptable repeatability rates, but the electronic shade determination showed higher repeatability. In general, the electronically determined shades were darker than the visually determined shades. The use of a camouflaged visual shade guide seems to be an adequate method to reduce operator bias.

  9. Healthy Sleep Habits

    Science.gov (United States)

    ... Sleep Apnea Testing CPAP Healthy Sleep Habits Healthy Sleep Habits Your behaviors during the day, and especially ... team at an AASM accredited sleep center . Quick Sleep Tips Follow these tips to establish healthy sleep ...

  10. Habitable Planets for Man

    National Research Council Canada - National Science Library

    Dole, Stephen H

    2007-01-01

    ..., and discusses how to search for habitable planets. Interestingly for our time, he also gives an appraisal of the earth as a planet and describes how its habitability would be changed if some of its basic properties were altered...

  11. Rearing a reading habit

    OpenAIRE

    Sridhar, M. S.

    2009-01-01

    Discusses the importance and ways of inculcating reading habit in children at the right age, describes the five reading phases in children along with interest and the material to satiate the need, explains how four deterministic factors affect the reading habit of children, enlists motivations that are behind the reading process with tips to improve reading habit of children.

  12. Linguistic camouflage in girls with autism spectrum disorder.

    Science.gov (United States)

    Parish-Morris, Julia; Liberman, Mark Y; Cieri, Christopher; Herrington, John D; Yerys, Benjamin E; Bateman, Leila; Donaher, Joseph; Ferguson, Emily; Pandey, Juhi; Schultz, Robert T

    2017-01-01

    Autism spectrum disorder (ASD) is diagnosed more frequently in boys than girls, even when girls are equally symptomatic. Cutting-edge behavioral imaging has detected "camouflaging" in girls with ASD, wherein social behaviors appear superficially typical, complicating diagnosis. The present study explores a new kind of camouflage based on language differences. Pauses during conversation can be filled with words like UM or UH, but research suggests that these two words are pragmatically distinct (e.g., UM is used to signal longer pauses, and may correlate with greater social communicative sophistication than UH). Large-scale research suggests that women and younger people produce higher rates of UM during conversational pauses than do men and older people, who produce relatively more UH. Although it has been argued that children and adolescents with ASD use UM less often than typical peers, prior research has not included sufficient numbers of girls to examine whether sex explains this effect. Here, we explore UM vs. UH in school-aged boys and girls with ASD, and ask whether filled pauses relate to dimensional measures of autism symptom severity. Sixty-five verbal school-aged participants with ASD (49 boys, 16 girls, IQ estimates in the average range) participated, along with a small comparison group of typically developing children (8 boys, 9 girls). Speech samples from the Autism Diagnostic Observation Schedule were orthographically transcribed and time-aligned, with filled pauses marked. Parents completed the Social Communication Questionnaire and the Vineland Adaptive Behavior Scales. Girls used UH less often than boys across both diagnostic groups. UH suppression resulted in higher UM ratios for girls than boys, and overall filled pause rates were higher for typical children than for children with ASD. Higher UM ratios correlated with better socialization in boys with ASD, but this effect was driven by increased use of UH by boys with greater symptoms. Pragmatic

  13. A "Mimic Octopus" in the Atlantic: Flatfish mimicry and camouflage by Macrotritopus defilippi.

    Science.gov (United States)

    Hanlon, Roger T; Watson, Anya C; Barbosa, Alexandra

    2010-02-01

    The sand-dwelling octopus Macrotritopus defilippi was filmed or photographed in five Caribbean locations mimicking the swimming behavior (posture, style, speed, duration) and coloration of the common, sand-dwelling flounder Bothus lunatus. Each species was exceptionally well camouflaged when stationary, and details of camouflaging techniques are described for M. defilippi. Octopuses implemented flounder mimicry only during swimming, when their movement would give away camouflage in this open sandy habitat. Thus, both camouflage and fish mimicry were used by the octopuses as a primary defense against visual predators. This is the first documentation of flounder mimicry by an Atlantic octopus, and only the fourth convincing case of mimicry for cephalopods, a taxon renowned for its polyphenism that is implemented mainly by neurally controlled skin patterning, but also-as shown here-by their soft flexible bodies.

  14. Using 2D image composition to model and evaluate soldier camouflage in the visible wavelengths

    CSIR Research Space (South Africa)

    Duvenhage B

    2011-06-01

    Full Text Available The development and evaluation of camouflage systems is usually very time-consuming. Any evaluation that could be done using simulation prior to a field deployment would significantly shorten the development cycle. One could for example use...

  15. Skeletal class III camouflage by mandibular incisor extraction: A case report

    OpenAIRE

    Janardhanan Kumaresan; Tamizharasi Senthil Kumar; Senthil Kumar

    2014-01-01

    Treatment planning in orthodontics plays a key role in determining the successful treatment of any kind of malocclusion. Skeletal class III malocclusions are generally difficult to treat because of the complex nature of the skeletal and dental manifestations they produce. Mild to moderate skeletal class III malocclusions sometimes have an acceptable facial profile where orthodontic camouflage is possible. In this case report, camouflage of a mild skeletal class III is done by the extraction o...

  16. Threshold-Dependent Camouflaged Cells to Secure Circuits Against Reverse Engineering Attacks

    OpenAIRE

    Collantes, Maria I. Mera; Massad, Mohamed El; Garg, Siddharth

    2016-01-01

    With current tools and technology, someone who has physical access to a chip can extract the detailed layout of the integrated circuit (IC). By using advanced visual imaging techniques, reverse engineering can reveal details that are meant to be kept secret, such as a secure protocol or novel implementation that offers a competitive advantage. A promising solution to defend against reverse engineering attacks is IC camouflaging. In this work, we propose a new camouflaging technique based on t...

  17. Full control and manipulation of heat signatures: cloaking, camouflage and thermal metamaterials.

    Science.gov (United States)

    Han, Tiancheng; Bai, Xue; Thong, John T L; Li, Baowen; Qiu, Cheng-Wei

    2014-03-19

    Thermal camouflage and cloaking can transform an actual heat signature into a pre-controlled one. A viable recipe for controlling and manipulating heat signatures using thermal metamaterials to empower cloaking and camouflage in heat conduction is demonstrated. The thermal signature of the object is thus metamorphosed and perceived as multiple targets with different geometries and compositions, with the original object cloaked. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Acne and cosmetics: a cross-sectional, web-based questionnaire survey of the views and opinions of Italian dermatologists on the use of camouflage cosmetics in female patients.

    Science.gov (United States)

    Mastrolonardo, Mario; Bonamonte, Domenico; Karlis, Xenophon; Fortunato, Francesca; Mazzarella, Francesco; Romita, Paolo; Foti, Caterina

    2017-10-01

    Unsatisfactory response rates are not rarely observed in the management of acne and seem largely related to poor adherence to treatment. As more specifically regards management of the disease in female patients, available literature provides contradictory indications regarding permissibility of using cosmetics. In this study we aimed to narrow our investigation on the habits of non-academic dermatologists specifically with regards to allowing/not-allowing their female patients to use camouflage cosmetics. A Web-based survey was carried out by sending an e-mail containing a brief, aim-oriented questionnaire to a random, nationwide sample of 1508 Italian colleagues. Basic demographic data (sex, age and seniority of specialization), and tick box and open responses to the questionnaire underwent statistical analyses, as appropriate. The response rate was 32.9% (N.=334), this meaning 7.6% of the entire (N.=4390) Italy-based dermatologist population. The outcome between pros-and-cons standpoints was substantially split in half, in that less more than half of interviewees felt "very" or "rather" important to prohibit the use of camouflage cosmetics to their patients and only allowed the use of make-up sporadically, i.e. on "special" occasions. Camouflage cosmetics in acne patients should not be a sort of taboo for each dermatologist needing to deal with it individually in his/her day-by-day clinical practice. On the other hand, what appears to be still missing is future third-party research on the actual feasibility of cosmetics, and of camouflage products in particular. Large scale, possibly split-face controlled evaluations would be in this view a gold standard to confide in.

  19. Orthodontic Camouflage: A Treatment Option – A Clinical Case Report

    Science.gov (United States)

    Mazzini, William Ubilla; Torres, Fátima Mazzini

    2017-01-01

    Orthodontic camouflage provides an alternative treatment for angle III malocclusion since patients with limited economic resources cannot opt for orthognathic surgery, it being clear that correction will be achieved at the dental level and not at the bone complex. Objective: To determine an alternative treatment for patients who do not have the possibility of having orthognathic surgery. Clinical case: A 13-year-old female patient, dolico facial biotype with slightly concave profile, with Class III Skeletal by mandibular prognathism, anterior crossbite, anterior diastema, and large mandibular body, molar class, and canine III. Alexander technique brackets were placed; premolar extraction was not planned. Once the case was completed, the correction of the anterior crossbite was achieved, thanks to the use of the spaces that existed at the beginning of the treatment and also that a correct distalization of canines and retraction of the lower anterior segment were performed. PMID:29326524

  20. Orthodontic Camouflage: A Treatment Option - A Clinical Case Report.

    Science.gov (United States)

    Mazzini, William Ubilla; Torres, Fátima Mazzini

    2017-01-01

    Orthodontic camouflage provides an alternative treatment for angle III malocclusion since patients with limited economic resources cannot opt for orthognathic surgery, it being clear that correction will be achieved at the dental level and not at the bone complex. To determine an alternative treatment for patients who do not have the possibility of having orthognathic surgery. A 13-year-old female patient, dolico facial biotype with slightly concave profile, with Class III Skeletal by mandibular prognathism, anterior crossbite, anterior diastema, and large mandibular body, molar class, and canine III. Alexander technique brackets were placed; premolar extraction was not planned. Once the case was completed, the correction of the anterior crossbite was achieved, thanks to the use of the spaces that existed at the beginning of the treatment and also that a correct distalization of canines and retraction of the lower anterior segment were performed.

  1. Validation of the use of synthetic imagery for camouflage effectiveness assessment

    Science.gov (United States)

    Newman, Sarah; Gilmore, Marilyn A.; Moorhead, Ian R.; Filbee, David R.

    2002-08-01

    CAMEO-SIM was developed as a laboratory method to assess the effectiveness of aircraft camouflage schemes. It is a physically accurate synthetic image generator, rendering in any waveband between 0.4 and 14 microns. Camouflage schemes are assessed by displaying imagery to observers under controlled laboratory conditions or by analyzing the digital image and calculating the contrast statistics between the target and background. Code verification has taken place during development. However, validation of CAMEO-SIM is essential to ensure that the imagery produced is suitable to be used for camouflage effectiveness assessment. Real world characteristics are inherently variable, so exact pixel to pixel correlation is unnecessary. For camouflage effectiveness assessment it is more important to be confident that the comparative effects of different schemes are correct, but prediction of detection ranges is also desirable. Several different tests have been undertaken to validate CAMEO-SIM for the purpose of assessing camouflage effectiveness. Simple scenes have been modeled and measured. Thermal and visual properties of the synthetic and real scenes have been compared. This paper describes the validation tests and discusses the suitability of CAMEO-SIM for camouflage assessment.

  2. Dynamic camouflage by Nassau groupers Epinephelus striatus on a Caribbean coral reef.

    Science.gov (United States)

    Watson, A C; Siemann, L A; Hanlon, R T

    2014-11-01

    This field study describes the camouflage pattern repertoire, associated behaviours and speed of pattern change of Nassau groupers Epinephelus striatus at Little Cayman Island, British West Indies. Three basic camouflaged body patterns were observed under natural conditions and characterized quantitatively. The mean speed of pattern change across the entire body was 4.44 s (range = 0.97-9.87 s); the fastest pattern change as well as contrast change within a fixed pattern occurred within 1 s. Aside from apparent defensive camouflage, E. striatus used camouflage offensively to approach crustacean or fish prey, and three successful predation events were recorded. Although animal camouflage is a widespread tactic, dynamic camouflage is relatively uncommon and has been studied rarely in marine teleosts under natural conditions. The rapid changes observed in E. striatus suggest direct neural control of some skin colouration elements, and comparative studies of functional morphology and behaviour of colour change in other coral-reef teleosts are likely to reveal new mechanisms and adaptations of dynamic colouration. © 2014 The Fisheries Society of the British Isles.

  3. Efficacy trial of Camouflage Syringe to reduce dental fear and anxiety.

    Science.gov (United States)

    Ujaoney, S; Mamtani, M; Thakre, T; Tote, J; Hazarey, V; Hazarey, P; Kulkarni, H

    2013-12-01

    Dental fear and anxiety in early childhood are widely prevalent and contribute to dental problems and behaviour in adulthood. Novel ways to reduce dental fear and anxiety in children are needed. Our aim was to conduct an efficacy trial of a novel Camouflage Syringe to reduce dental fear and anxiety in children. randomised controlled trial of efficacy of the Camouflage Syringe. We designed a Camouflage Syringe with a toy-like appearance that veils the conventional syringe to permit topical application and injection of local anaesthesia and ensure more involvement of the patient in the treatment process. We conducted a concurrent parallel, randomised controlled trial (NCT01398007) on the efficacy of this Camouflage Syringe to reduce the dental fear and anxiety in children seeking dental treatment who required the use of local anaesthesia. Using Venham's clinical rating scale, Venham's picture test, parental stress questionnaire and recall questionnaire, the efficacy of the Camouflage Syringe to reduce dental fear and anxiety ranged from 82% to 97% for various outcomes and from 60% to 100% for prevention of related adverse outcomes. For all outcomes, the number needed to treat was close to unity. Our results strongly favour the use of Camouflage Syringe to reduce dental fear and anxiety in children.

  4. [Design of plant leaf bionic camouflage materials based on spectral analysis].

    Science.gov (United States)

    Yang, Yu-Jie; Liu, Zhi-Ming; Hu, Bi-Ru; Wu, Wen-Jian

    2011-06-01

    The influence of structure parameters and contents of plant leaves on their reflectance spectra was analyzed using the PROSPECT model. The result showed that the bionic camouflage materials should be provided with coarse surface and spongy inner structure, the refractive index of main content must be close to that of plant leaves, the contents of materials should contain chlorophyll and water, and the content of C-H bond must be strictly controlled. Based on the analysis above, a novel camouflage material, which was constituted by coarse transparent waterproof surface, chlorophyll, water and spongy material, was designed. The result of verifiable experiment showed that the reflectance spectra of camouflage material exhibited the same characteristics as those of plant leaves. The similarity coefficient of reflectance spectrum of the camouflage material and camphor leaves was 0.988 1, and the characteristics of camouflage material did not change after sunlight treatment for three months. The bionic camouflage material, who exhibited a high spectral similarity with plant leaves and a good weather resistance, will be an available method for reconnaissance of hyperspectral imaging hopefully.

  5. Color Change for Thermoregulation versus Camouflage in Free-Ranging Lizards.

    Science.gov (United States)

    Smith, Kathleen R; Cadena, Viviana; Endler, John A; Kearney, Michael R; Porter, Warren P; Stuart-Fox, Devi

    2016-12-01

    Animal coloration has multiple functions including thermoregulation, camouflage, and social signaling, and the requirements of each function may sometimes conflict. Many terrestrial ectotherms accommodate the multiple functions of color through color change. However, the relative importance of these functions and how color-changing species accommodate them when they do conflict are poorly understood because we lack data on color change in the wild. Here, we show that the color of individual radio-tracked bearded dragon lizards, Pogona vitticeps, correlates strongly with background color and less strongly, but significantly, with temperature. We found no evidence that individuals simultaneously optimize camouflage and thermoregulation by choosing light backgrounds when hot or dark backgrounds when cold. In laboratory experiments, lizards showed both UV-visible (300-700 nm) and near-infrared (700-2,100 nm) reflectance changes in response to different background and temperature treatments, consistent with camouflage and thermoregulatory functions, respectively, but with no interaction between the two. Overall, our results suggest that wild bearded dragons change color to improve both thermoregulation and camouflage but predominantly adjust for camouflage, suggesting that compromising camouflage may entail a greater potential immediate survival cost.

  6. Evaluation of camouflage pattern performance of textiles by human observers and CAMAELEON

    Science.gov (United States)

    Heinrich, Daniela H.; Selj, Gorm K.

    2017-10-01

    Military textiles with camouflage pattern are an important part of the protection measures for soldiers. Military operational environments differ a lot depending on climate and vegetation. This requires very different camouflage pattern to achieve good protection. To find the best performing pattern for given environments we have in earlier evaluations mainly applied observer trials as evaluation method. In these camouflage evaluation test human observers were asked to search for targets (in natural settings) presented on a high resolution PC screen, and the corresponding detection times were recorded. Another possibility is to base the evaluation on simulations. CAMAELEON is a licensed tool that ranks camouflaged targets by their similarity with local backgrounds. The similarity is estimated through the parameters local contrast, orientation of structures in the pattern and spatial frequency, by mimicking the response and signal processing in the visual cortex of the human eye. Simulations have a number of advantages over observer trials, for example, that they are more flexible, cheaper, and faster. Applying these two methods to the same images of camouflaged targets we found that CAMAELEON simulation results didn't match observer trial results for targets with disruptive patterns. This finding now calls for follow up studies in order to learn more about the advantages and pitfalls of CAMAELEON. During recent observer trials we studied new camouflage patterns and the effect of additional equipment, such as combat vests. In this paper we will present the results from a study comparing evaluation results of human based observer trials and CAMAELEON.

  7. Il camouflage nel campo allargato. Variazioni su Disruptive Pattern Material e Dazzle Painting nella cultura visiva contemporanea

    Directory of Open Access Journals (Sweden)

    Maite Méndez Baiges

    2016-11-01

    Full Text Available The First World War was the scenario that led to the invention and systematic use of military camouflage techniques. Between them, the two fundamental modes of static or pictorial camouflage: mimetic, known as Disruptive Pattern Material, and the naval, called Dazzle Painting. Avantgarde artists contributed to their birth. Immediately, there was the transfer of these techniques to the civilian sphere, revealing that its essentially practical essence did not prevent the exploitation of its aesthetic potential by contemporary visual culture. Throughout the twentieth and twenty-first centuries the fields of art, architecture and design continue importing and exploiting the strategies of these two types of military camouflage. This article analyzes the artistic potential of static military camouflage devised during World War I and its impact on the setting of an expanded notion of camouflage. If the camouflage was in its origins and early history a form of disclosure of modern art on a global scale, the use of DPM and Dazzle by contemporary artists, is a form of dissemination of military camouflage to civil level. We explore a double investment produced by military camouflage: providing avantgarde art with a practical sense, and providing camouflage with an aesthetic sense

  8. Size Matters: Observed and Modeled Camouflage Response of European Cuttlefish (Sepia officinalis) to Different Substrate Patch Sizes during Movement.

    Science.gov (United States)

    Josef, Noam; Berenshtein, Igal; Rousseau, Meghan; Scata, Gabriella; Fiorito, Graziano; Shashar, Nadav

    2016-01-01

    Camouflage is common throughout the phylogenetic tree and is largely used to minimize detection by predator or prey. Cephalopods, and in particular Sepia officinalis cuttlefish, are common models for camouflage studies. Predator avoidance behavior is particularly important in this group of soft-bodied animals that lack significant physical defenses. While previous studies have suggested that immobile cephalopods selectively camouflage to objects in their immediate surroundings, the camouflage characteristics of cuttlefish during movement are largely unknown. In a heterogenic environment, the visual background and substrate feature changes quickly as the animal swim across it, wherein substrate patch is a distinctive and high contrast patch of substrate in the animal's trajectory. In the current study, we examine the effect of substrate patch size on cuttlefish camouflage, and specifically the minimal size of an object for eliciting intensity matching response while moving. Our results indicated that substrate patch size has a positive effect on animal's reflectance change, and that the threshold patch size resulting in camouflage response falls between 10 and 19 cm (width). These observations suggest that the animal's length (7.2-12.3 cm mantle length in our case) serves as a possible threshold filter below which objects are considered irrelevant for camouflage, reducing the frequency of reflectance changes-which may lead to detection. Accordingly, we have constructed a computational model capturing the main features of the observed camouflaging behavior, provided for cephalopod camouflage during movement.

  9. A study of Class III treatment: orthodontic camouflage vs orthognathic surgery.

    Science.gov (United States)

    Georgalis, Katherine; Woods, Michael G

    2015-11-01

    To evaluate the differences in pretreatment and post-treatment characteristics of Class III patients treated with orthodontic camouflage or orthognathic surgery, and to compare the range of skeletal, dental and soft tissue changes that are likely to occur with treatment, with particular reference to the influence of extractions on the resultant incisor angulations. Pretreatment and post-treatment cephalograms of 31 Class III orthodontically-camouflaged patients and 36 Class III surgical patients (without genioplasty) were obtained from one specialist practice. From the surgical group, 26 pre-surgical lateral cephalograms were also obtained. Inclusion criteria for the two groups were at least three of the following: (1) an ANB angle of 1 degree or less, (2) a Wits appraisal less than -4 mm, (3) an incisal overjet ≤ 0 mm, and (14) a Class III molar relationship. All lateral cephalograms were traced and digitised and a number of skeletal, dental and soft tissue variables were measured. The camouflage and surgical groups were also divided into premolar extraction and non-extraction subgroups to allow for a specific analysis of extraction effects. Before treatment, the surgical group demonstrated, on average, a more severe skeletal discrepancy and increased dental compensations, compared with the orthodontically camouflaged group. After treatment, the mean SNA angle was greater, the ANB angle was more positive, the Wits appraisal was closer to ideal and the lower incisors were less retroclined in the surgery group. There was a small mean reduction in horizontal chin projection in the surgery group compared with a small increase in the camouflage group. The mentolabial fold and the lower lip curve were deeper, on average, and the lips less retrusive after surgery. There was a mean increase in upper incisor proclination during treatment in both the surgical and camouflage groups with a greater increase in the camouflage group. There was a significant reduction in upper

  10. Male mate choice and female response in relation to mating status and time since mating

    OpenAIRE

    Douglass H. Morse

    2010-01-01

    Models of sperm allocation predict that male mating behavior will vary with a female's reproductive condition and with information about her present and likely future status available to a male. Tests across a wide taxonomic range have shown that males allocate more sperm to previously mated females than to virgins but that in a minority of instances this allocation pattern is reversed. To investigate the basis for this discrepancy I ran sequential pairings of the crab spider Misumena vatia (...

  11. Habitability: A Review.

    Science.gov (United States)

    Cockell, C S; Bush, T; Bryce, C; Direito, S; Fox-Powell, M; Harrison, J P; Lammer, H; Landenmark, H; Martin-Torres, J; Nicholson, N; Noack, L; O'Malley-James, J; Payler, S J; Rushby, A; Samuels, T; Schwendner, P; Wadsworth, J; Zorzano, M P

    2016-01-01

    Habitability is a widely used word in the geoscience, planetary science, and astrobiology literature, but what does it mean? In this review on habitability, we define it as the ability of an environment to support the activity of at least one known organism. We adopt a binary definition of "habitability" and a "habitable environment." An environment either can or cannot sustain a given organism. However, environments such as entire planets might be capable of supporting more or less species diversity or biomass compared with that of Earth. A clarity in understanding habitability can be obtained by defining instantaneous habitability as the conditions at any given time in a given environment required to sustain the activity of at least one known organism, and continuous planetary habitability as the capacity of a planetary body to sustain habitable conditions on some areas of its surface or within its interior over geological timescales. We also distinguish between surface liquid water worlds (such as Earth) that can sustain liquid water on their surfaces and interior liquid water worlds, such as icy moons and terrestrial-type rocky planets with liquid water only in their interiors. This distinction is important since, while the former can potentially sustain habitable conditions for oxygenic photosynthesis that leads to the rise of atmospheric oxygen and potentially complex multicellularity and intelligence over geological timescales, the latter are unlikely to. Habitable environments do not need to contain life. Although the decoupling of habitability and the presence of life may be rare on Earth, it may be important for understanding the habitability of other planetary bodies.

  12. Space Station Habitability Research

    Science.gov (United States)

    Clearwater, Yvonne A.

    1988-01-01

    The purpose and scope of the Habitability Research Group within the Space Human Factors Office at the NASA/Ames Research Center is described. Both near-term and long-term research objectives in the space human factors program pertaining to the U.S. manned Space Station are introduced. The concept of habitability and its relevancy to the U.S. space program is defined within a historical context. The relationship of habitability research to the optimization of environmental and operational determinants of productivity is discussed. Ongoing habitability research efforts pertaining to living and working on the Space Station are described.

  13. Nest covering in plovers: How modifying the visual environment influences egg camouflage.

    Science.gov (United States)

    Troscianko, Jolyon; Wilson-Aggarwal, Jared; Spottiswoode, Claire N; Stevens, Martin

    2016-10-01

    Camouflage is one of the most widespread antipredator defences, and its mechanistic basis has attracted considerable interest in recent years. The effectiveness of camouflage depends on the interaction between an animal's appearance and its background. Concealment can therefore be improved by changes to an animal's own appearance, by behaviorally selecting an optimal background, or by modifying the background to better match the animal's own appearance. Research to date has largely focussed on the first of these mechanisms, whereas there has been little work on the second and almost none on the third. Even though a number of animal species may potentially modify their environment to improve individual-specific camouflage, this has rarely if ever been quantitatively investigated, or its adaptive value tested. Kittlitz's plovers (Charadrius pecuarius) use material (stones and vegetation) to cover their nests when predators approach, providing concealment that is independent of the inflexible appearance of the adult or eggs, and that can be adjusted to suit the local surrounding background. We used digital imaging and predator vision modeling to investigate the camouflage properties of covered nests, and whether their camouflage affected their survival. The plovers' nest-covering materials were consistent with a trade-off between selecting materials that matched the color of the eggs, while resulting in poorer nest pattern and contrast matching to the nest surroundings. Alternatively, the systematic use of materials with high-contrast and small-pattern grain sizes could reflect a deliberate disruptive coloration strategy, whereby high-contrast material breaks up the telltale outline of the clutch. No camouflage variables predicted nest survival. Our study highlights the potential for camouflage to be enhanced by background modification. This provides a flexible system for modifying an animal's conspicuousness, to which the main limitation may be the available

  14. On the Habitability of Aquaplanets

    OpenAIRE

    Rolando Cardenas; Noel Perez; Jesus Martinez-Frias; Osmel Martin

    2014-01-01

    An Aquatic Habitability Index is proposed, based on Quantitative Habitability Theory, and considering a very general model for life. It is a primary habitability index, measuring habitability for phytoplankton in the first place. The index is applied to some case studies, such as the habitability changes in Earth due to environmental perturbations caused by asteroid impacts.

  15. On the Habitability of Aquaplanets

    Directory of Open Access Journals (Sweden)

    Rolando Cardenas

    2014-08-01

    Full Text Available An Aquatic Habitability Index is proposed, based on Quantitative Habitability Theory, and considering a very general model for life. It is a primary habitability index, measuring habitability for phytoplankton in the first place. The index is applied to some case studies, such as the habitability changes in Earth due to environmental perturbations caused by asteroid impacts.

  16. Your Child's Habits

    Science.gov (United States)

    ... older. For those who don't, simple behavior modification can help them break the habit. However, for those who start hair pulling as ... in your mirror. Do you bite your nails? Studies suggest that nail biting may ... kids engage in habits to attract attention or to manipulate their parents. ...

  17. MATE. Multi Aircraft Training Environment

    DEFF Research Database (Denmark)

    Hauland, G.; Bove, T.; Andersen, Henning Boje

    2002-01-01

    A medium fidelity and low cost training device for pilots, called the Multi Aircraft Training Environment (MATE), is developed to replace other low fidelity stand-alone training devices and integrate them into a flexible environment, primarily aimed attraining pilots in checklist procedures....../models to be simulated) and with possibilities for including various forms of intelligent computer assistance. This training concept and the technology are not specific toaviation, but can be used to simulate various types of control panels in different domains. The training effectiveness of pilots' procedure training...... in the MATE prototype was compared with the effects of traditional training that included the use of realaircraft. The experimental group (EXP) trained the pre-start checklist and the engine start checklist for the Saab 340 commuter aircraft in a MATE prototype. The control group (CTR) trained the same...

  18. Car-use habits

    DEFF Research Database (Denmark)

    Møller, Berit Thorup; Thøgersen, John

    2008-01-01

    It is often claimed that many drivers use their private car rather habitually. The claim gains credibility from the fact that travelling to many everyday destinations fulfils all the prerequisites for habit formation: it is recurring, performed under stable circumstances and produces rewarding...... consequences. Since the decision is made quite automatically and only one choice alternative is considered (the habitually chosen one), behaviour guided by habit is difficult to change. The implications of car use habits for converting drivers to commuters using public transportation is analysed based...... to do so, car use habit, and the interaction between the two, confirms the theory-derived hypothesis that car use habits act as an obstacle to the transformation of intentions to commute by public transportation into action....

  19. Emotional benefit of cosmetic camouflage in the treatment of facial skin conditions: personal experience and review.

    Science.gov (United States)

    Levy, Lauren L; Emer, Jason J

    2012-01-01

    Recent studies highlighting the psychological benefits of medical treatment for dermatological skin conditions have demonstrated a clear role for medical therapy in psychological health. Skin conditions, particularly those that are overtly visible, such as those located on the face, neck, and hands, often have a profound effect on the daily functioning of those affected. The literature documents significant emotional benefits using medical therapy in conditions such as acne, psoriasis, vitiligo, and rosacea, but there is little evidence documenting similar results with the use of cosmetic camouflage. Here we present a review highlighting the practical use of cosmetic camouflage makeup in patients with facial skin conditions and review its implications for psychological health. A search of the Medline and Scopus databases was performed to identify articles documenting the emotional benefit of cosmetic camouflage. Cosmetic camouflage provides a significant emotional benefit for patients with facial skin conditions, and this is substantiated by a literature review and personal experience. More clinical studies are needed to assess and validate the findings reported here. Patients with visible skin conditions have increased rates of depression, anxiety, and decreased self-esteem. It is prudent for us to consider therapies that can offer rapid and dramatic results, such as cosmetic camouflage.

  20. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Science.gov (United States)

    Conroy-Beam, Daniel; Buss, David M

    2016-01-01

    Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  1. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Directory of Open Access Journals (Sweden)

    Daniel Conroy-Beam

    Full Text Available Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294 we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  2. Camouflaged target detection based on polarized spectral features

    Science.gov (United States)

    Tan, Jian; Zhang, Junping; Zou, Bin

    2016-05-01

    The polarized hyperspectral images (PHSI) include polarization, spectral, spatial and radiant features, which provide more information about objects and scenes than traditional intensity or spectrum ones. And polarization can suppress the background and highlight the object, leading to the high potential to improve camouflaged target detection. So polarized hyperspectral imaging technique has aroused extensive concern in the last few years. Nowadays, the detection methods are still not very mature, most of which are rooted in the detection of hyperspectral image. And before using these algorithms, Stokes vector is used to process the original four-dimensional polarized hyperspectral data firstly. However, when the data is large and complex, the amount of calculation and error will increase. In this paper, tensor is applied to reconstruct the original four-dimensional data into new three-dimensional data, then, the constraint energy minimization (CEM) is used to process the new data, which adds the polarization information to construct the polarized spectral filter operator and takes full advantages of spectral and polarized information. This way deals with the original data without extracting the Stokes vector, so as to reduce the computation and error greatly. The experimental results also show that the proposed method in this paper is more suitable for the target detection of the PHSI.

  3. ANALYSIS OF CAMOUFLAGE COVER SPECTRAL CHARACTERISTICS BY IMAGING SPECTROMETER

    Directory of Open Access Journals (Sweden)

    A. Y. Kouznetsov

    2016-03-01

    Full Text Available Subject of Research.The paper deals with the problems of detection and identification of objects in hyperspectral imagery. The possibility of object type determination by statistical methods is demonstrated. The possibility of spectral image application for its data type identification is considered. Method. Researching was done by means of videospectral equipment for objects detection at "Fregat" substrate. The postprocessing of hyperspectral information was done with the use of math model of pattern recognition system. The vegetation indexes TCHVI (Three-Channel Vegetation Index and NDVI (Normalized Difference Vegetation Index were applied for quality control of object recognition. Neumann-Pearson criterion was offered as a tool for determination of objects differences. Main Results. We have carried out analysis of the spectral characteristics of summer-typecamouflage cover (Germany. We have calculated the density distribution of vegetation indexes. We have obtained statistical characteristics needed for creation of mathematical model for pattern recognition system. We have shown the applicability of vegetation indices for detection of summer camouflage cover on averdure background. We have presented mathematical model of object recognition based on Neumann-Pearson criterion. Practical Relevance. The results may be useful for specialists in the field of hyperspectral data processing for surface state monitoring.

  4. Habitable Zones in the Universe

    OpenAIRE

    Gonzalez, G.

    2005-01-01

    Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review...

  5. Mate choice screening in captive solitary carnivores

    DEFF Research Database (Denmark)

    Noer, Christina Lehmkuhl; Balsby, Thorsten Johannes Skovbjerg; Anistoroaei, Razvan

    2017-01-01

    Mate choice studies suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose among potential mates, deemed genetically suitable based on studbook data, might improve breeding management in production ...

  6. Camouflage of moderate Class III malocclusions with extraction of lower second molars and mandibular cervical headgear.

    Science.gov (United States)

    Mora, Diego Rey; Oberti, Giovanni; Ealo, Martha; Baccetti, Tiziano

    2007-01-01

    Orthodontic camouflage in patients with slight or moderate skeletal Class III malocclusions, can be obtained through different treatment alternatives. The purpose of this paper is to present a treatment that has not been described in the literature and which consists of the extraction of lower second molars and distal movement of the posterior segments by means of mandibular cervical headgear (MCH) and fixed appliances as a camouflage alternative. The force applied by the MCH was 250 gr per side (14hr/day). The total treatment time was 1 1/2 years. the extraction of lower second molars along with the use of mandibular cervical headgear is a good treatment alternative for camouflage in moderate Class III patients in order to obtain good occlusal relationships without affecting facial esthetics or producing marked dental compensations.

  7. Camouflaging in a complex environment--octopuses use specific features of their surroundings for background matching.

    Directory of Open Access Journals (Sweden)

    Noam Josef

    Full Text Available Living under intense predation pressure, octopuses evolved an effective and impressive camouflaging ability that exploits features of their surroundings to enable them to "blend in." To achieve such background matching, an animal may use general resemblance and reproduce characteristics of its entire surroundings, or it may imitate a specific object in its immediate environment. Using image analysis algorithms, we examined correlations between octopuses and their backgrounds. Field experiments show that when camouflaging, Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer.

  8. CAMOUFLAGE AND ITS IMPACT ON AUSTRALIA IN WWII: AN ART HISTORIAN’S PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Ann Elias

    2016-03-01

    Full Text Available The impact of modern camouflage on Australian military practices and on the public imagination intensified during the Second World War. A new organisation was created to support national security through concealment and deception. Its core members were civilians and included a zoologist who specialised in animal camouflage as well as a group of Australia’s leading artists who specialised in optical tricks and visual illusions. While concealment and deception remain central to contemporary approaches to national security (i.e. part of a counterintelligence strategy, the history outlined here draws attention to ethical conflicts and conceptual struggles in relation to camouflage and warfare that were important in WWII, but may seem quaint today.

  9. UAS stealth: target pursuit at constant distance using a bio-inspired motion camouflage guidance law.

    Science.gov (United States)

    Strydom, Reuben; Srinivasan, Mandyam V

    2017-09-21

    The aim of this study is to derive a guidance law by which an unmanned aerial system(s) (UAS) can pursue a moving target at a constant distance, while concealing its own motion. We derive a closed-form solution for the trajectory of the UAS by imposing two key constraints: (1) the shadower moves in such a way as to be perceived as a stationary object by the shadowee, and (2) the distance between the shadower and shadowee is kept constant. Additionally, the theory presented in this paper considers constraints on the maximum achievable speed and acceleration of the shadower. Our theory is tested through Matlab simulations, which validate the camouflage strategy for both 2D and 3D conditions. Furthermore, experiments using a realistic vision-based implementation are conducted in a virtual environment, where the results demonstrate that even with noisy state information it is possible to remain well camouflaged using the constant distance motion camouflage technique.

  10. Camouflage design and head measurement characteristic of Indonesian armoured vehicle helmet

    Science.gov (United States)

    Sya'bana, Yukhi Mustaqim Kusuma; Sanjaya, K. H.

    2017-01-01

    In this paper discussed camouflage design helmet for armored vehicles with comparing head measurement of Indonesian anthropometric. Design process conduct with considering of design aspects involves function, materials, operational, technology, user, and appearance (camouflage). As an application of Indonesian National Army that qualifies factors needs: safety, comfort, practical and service. MIL-H-44099A Military Specification: Helmet, Ground Troops And Parachutists is minimum limitation standard of military helmet production. Head measurement for product design process guide is presented. Model simulation and helmet measurement using the design for ego and design for more types ergonomics concept. Appearance shape concept is engaging camouflage towards background and environment to deceive enemy viewpoint. Helmet prototype has tested ergonomically to an Indonesian National Army soldier and stated that the helmet size is a comfort and fitted on the head when in use.

  11. Protecting artificial team-mates

    DEFF Research Database (Denmark)

    Merritt, Timothy; McGee, Kevin

    2012-01-01

    Previous research on conversational, competitive, and cooperative systems suggests that people respond differently to humans and AI agents in terms of perception and evaluation of observed team-mate behavior. However, there has not been research examining the relationship between participants' pr...

  12. Diet-induced mating preference in Drosophila

    OpenAIRE

    Rosenberg, Eugene; Zilber-Rosenberg, Ilana; Sharon, Gil; Segal, Daniel

    2018-01-01

    Diet-induced mating preference was initially observed by Dodd (1). Subsequently, we reported that diet-induced mating preference occurred in Drosophila melanogaster. Treatment of the flies with antibiotics abolished the mating preference, suggesting that fly-associated commensal bacteria were responsible for the phenomenon (2). The hypothesis was confirmed when it was shown that colonizing antibiotic-treated flies with Lactobacillus plantarum reestablished mating preference in multiple-choice...

  13. Shape, colour plasticity, and habitat use indicate morph-specific camouflage strategies in a marine shrimp.

    Science.gov (United States)

    Duarte, Rafael C; Stevens, Martin; Flores, Augusto A V

    2016-10-18

    Colour and shape polymorphisms are important features of many species and may allow individuals to exploit a wider array of habitats, including through behavioural differences among morphs. In addition, differences among individuals in behaviour and morphology may reflect different strategies, for example utilising different approaches to camouflage. Hippolyte obliquimanus is a small shrimp species inhabiting different shallow-water vegetated habitats. Populations comprise two main morphs: homogeneous shrimp of variable colour (H) and transparent individuals with coloured stripes (ST). These morphs follow different distribution patterns between their main algal habitats; the brown weed Sargassum furcatum and the pink-red weed Galaxaura marginata. In this study, we first investigated morph-specific colour change and habitat selection, as mechanisms underlying camouflage and spatial distribution patterns in nature. Then, we examined habitat fidelity, mobility, and morphological traits, further indicating patterns of habitat use. H shrimp are capable of changing colour in just a few days towards their algal background, achieving better concealment in the more marginal, and less preferred, red weed habitat. Furthermore, laboratory trials showed that habitat fidelity is higher for H shrimp, whereas swimming activity is higher for the ST morph, aligned to morphological evidence indicating these two morphs comprise a more benthic (H) and a more pelagic (ST) life-style, respectively. Results suggest that H shrimp utilise a camouflage strategy specialised to a limited number of backgrounds at any one time, whereas ST individuals comprise a phenotype with more generalist camouflage (transparency) linked to a more generalist background utilisation. The coexistence within a population of distinct morphotypes with apparently alternative strategies of habitat use and camouflage may reflect differential responses to substantial seasonal changes in macroalgal cover. Our findings

  14. The evolution of pattern camouflage strategies in waterfowl and game birds.

    Science.gov (United States)

    Marshall, Kate L A; Gluckman, Thanh-Lan

    2015-05-01

    Visual patterns are common in animals. A broad survey of the literature has revealed that different patterns have distinct functions. Irregular patterns (e.g., stipples) typically function in static camouflage, whereas regular patterns (e.g., stripes) have a dual function in both motion camouflage and communication. Moreover, irregular and regular patterns located on different body regions ("bimodal" patterning) can provide an effective compromise between camouflage and communication and/or enhanced concealment via both static and motion camouflage. Here, we compared the frequency of these three pattern types and traced their evolutionary history using Bayesian comparative modeling in aquatic waterfowl (Anseriformes: 118 spp.), which typically escape predators by flight, and terrestrial game birds (Galliformes: 170 spp.), which mainly use a "sit and hide" strategy to avoid predation. Given these life histories, we predicted that selection would favor regular patterning in Anseriformes and irregular or bimodal patterning in Galliformes and that pattern function complexity should increase over the course of evolution. Regular patterns were predominant in Anseriformes whereas regular and bimodal patterns were most frequent in Galliformes, suggesting that patterns with multiple functions are broadly favored by selection over patterns with a single function in static camouflage. We found that the first patterns to evolve were either regular or bimodal in Anseriformes and either irregular or regular in Galliformes. In both orders, irregular patterns could evolve into regular patterns but not the reverse. Our hypothesis of increasing complexity in pattern camouflage function was supported in Galliformes but not in Anseriformes. These results reveal a trajectory of pattern evolution linked to increasing function complexity in Galliformes although not in Anseriformes, suggesting that both ecology and function complexity can have a profound influence on pattern evolution.

  15. Determination of mating frequency by radiotracer technique

    International Nuclear Information System (INIS)

    Hamid Miah, M.A.

    1978-01-01

    Radioisotope ( 32 P) was used to study the frequency of mating of an insect. The radioactivity counts correlated positively with the number of matings. Radioactivity was also detected from the eggs and excised embryos. This work suggests that radioisotope like ( 32 P) may be conveninently used to detect virginity and mating frequency of female insects without killing them. (author)

  16. BUFO PARDALIS (ANURA: BUFONIDAE): MATING CALL AND ...

    African Journals Online (AJOL)

    the calls of one of these species, Bufo pardalis. Hewitt, were not analysed by Tandy & Keith. (1972). Furthennore there is some confusion in the literature regarding the mating call of this species. For these reasons this mating call is here clarified. The mating call of B. pardaiis was first described by Ranger (in Hewitt 1935) as ...

  17. Use of makeup, hairstyles, glasses, and prosthetics as adjuncts to scar camouflage.

    Science.gov (United States)

    Sidle, Douglas M; Decker, Jennifer R

    2011-08-01

    Scars after facial trauma or surgery can be a source of distress for patients, and facial plastic surgeons are frequently called upon to help manage them. Although no technique can remove a scar, numerous treatment modalities have been developed to improve facial scar appearance with varying levels of invasiveness. This article reviews techniques that camouflage scars without surgical intervention. Topical scar treatments, camouflage cosmetics, use of hairstyling and glasses, and facial prosthetics are discussed. In addition, professional counseling is provided on selection and application of topical cosmetics for use as part of an office practice. 2011 Elsevier Inc. All rights reserved.

  18. Skeletal class III camouflage by mandibular incisor extraction: A case report

    Directory of Open Access Journals (Sweden)

    Janardhanan Kumaresan

    2014-01-01

    Full Text Available Treatment planning in orthodontics plays a key role in determining the successful treatment of any kind of malocclusion. Skeletal class III malocclusions are generally difficult to treat because of the complex nature of the skeletal and dental manifestations they produce. Mild to moderate skeletal class III malocclusions sometimes have an acceptable facial profile where orthodontic camouflage is possible. In this case report, camouflage of a mild skeletal class III is done by the extraction of a single mandibular incisor, which helped in maintaining the profile of the patient and also in the correction of crowding in the mandibular anterior region.

  19. Consumption Habits and Humps

    DEFF Research Database (Denmark)

    Kraft, Holger; Munk, Claus; Seifried, Frank Thomas

    2017-01-01

    We show that the optimal consumption of an individual over the life cycle can have the hump shape (inverted U-shape) observed empirically if the preferences of the individual exhibit internal habit formation. In the absence of habit formation, an impatient individual would prefer a decreasing...... consumption path over life. However, because of habit formation, a high initial consumption would lead to high required consumption in the future. To cover the future required consumption, wealth is set aside, but the necessary amount decreases with age which allows consumption to increase in the early part...... of life. At some age, the impatience outweighs the habit concerns so that consumption starts to decrease. We derive the optimal consumption strategy in closed form, deduce sufficient conditions for the presence of a consumption hump, and characterize the age at which the hump occurs. Numerical examples...

  20. Habitability: CAMELOT 4

    Science.gov (United States)

    Alequin, W.; Barragan, A.; Carro, M.; Garcia, F.; Gonzalez, I.; Mercado, J. A.; Negron, N.; Lopez, D.; Rivera, L. A.; Rivera, M.

    1990-01-01

    During 1988 to 1989 the NASA/USRA Advanced Design Program sponsored research and design efforts aimed at developing habitability criteria and at defining a habitability concept as a useful tool in understanding and evaluating dwellings for prolonged stays in extraterrestrial space. The Circulating Auto sufficient Mars-Earth Luxurious Orbital Transport (CAMELOT) was studied as a case in which the students would try to enhance the quality of life of the inhabitants by applying architectural design methodology. The study proposed 14 habitability criteria considered necessary to fulfill the defined habitability concept, which is that state of equilibrium that results from the interaction between components of the Individual Architecture Mission Complex, which allows a person to sustain physiological homeostatis, adequate performance, and acceptable social relationships. Architecture, design development, refinements and revisions to improve the quality of life, new insights on artificial gravity, form and constitution problems, and the final design concept are covered.

  1. Consumption Habits and Humps

    DEFF Research Database (Denmark)

    Kraft, Holger; Munk, Claus; Seifried, Frank Thomas

    We show that the optimal consumption of an individual over the life cycle can have the hump shape (inverted U-shape) observed empirically if the preferences of the individual exhibit internal habit formation. In the absence of habit formation, an impatient individual would prefer a decreasing...... consumption path over life. However, because of habit formation, a high initial consumption would lead to high required consumption in the future. To cover the future required consumption, wealth is set aside, but the necessary amount decreases with age which allows consumption to increase in the early part...... of life. At some age, the impatience outweighs the habit concerns so that consumption starts to decrease. We derive the optimal consumption strategy in closed form, deduce sufficient conditions for the presence of a consumption hump, and characterize the age at which the hump occurs. Numerical examples...

  2. Habitability and the Multiverse

    Science.gov (United States)

    Sandora, M. E.

    2017-11-01

    Are the laws of physics set to maximize the habitability of the universe? We study how plate tectonics, core and mantle composition, homochirality, photosynthesis, and planet size depend on physics, and make predictions for where life will be found.

  3. Food Habits Database (FHDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Food Habits Database has two major sources of data. The first, and most extensive, is the standard NEFSC Bottom Trawl Surveys Program. During these...

  4. A Review of Habit Reversal with Childhood Habit Disorders.

    Science.gov (United States)

    Woods, Douglas W.; Miltenberger, Raymond G.

    1996-01-01

    This paper first reviews four classes of habit disorders in children: motor and vocal tics, nervous habits, stuttering, and Tourette's disorder. It then describes the habit reversal procedure and reviews the literature on its use and variations to treat each of the four classes of habit disorders. Emphasis is on simplified versions of the original…

  5. Eating habits of students

    OpenAIRE

    Hoyer, Silvestra; Zupančič, Andreja

    2015-01-01

    The article deals with eating habits of students. Its purpose was to ascertaineating habits of students living outside their primary home and are under different forms of stress. Methods: the pattern is represented by students living in student homer where they can cook and prepare their own meals. In the research, 81 students living in the students home on Cesta v Mestni log in Ljubljana. The inquiry was composed from 34 questions. The data were processed with Microsoft Excel. Body mass inde...

  6. Hygiene habits through time

    OpenAIRE

    Kalan, Petra

    2013-01-01

    In this work I did a research about hygiene habits of people and their home environment. The work presents how the hygiene habits changed in people home environment through time. The work presents changes of the body hygiene standards adopted by people from the middle ages onward. Todays customs are quite different from the ones we had some time ago. Moreover, hygiene of living environment has also changes which resulted into lower death rate and death illness related to bad hygiene among pop...

  7. Females use self-referent cues to avoid mating with previous mates

    OpenAIRE

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-01-01

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that...

  8. Individual differences in valuing mates' physical attractiveness.

    Science.gov (United States)

    Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

    2006-10-01

    To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

  9. Self-Perceived Mate Value, Facial Attractiveness, and Mate Preferences: Do Desirable Men Want It All?

    Science.gov (United States)

    Arnocky, Steven

    2018-01-01

    Ten years ago, Buss and Shackelford demonstrated that high mate value (i.e., physically attractive) women held more discerning mate preferences relative to lower mate value women. Since then, researchers have begun to consider the equally important role of men's sexual selectivity in human mate choice. Yet, little research has focused on whether high mate value men are similarly choosy in their mate preferences. In a sample of 139 undergraduate men, relationships between self-perceived mate value as well as female-rated facial attractiveness were examined in relation to men's expressed mate preferences. Results showed that self-perceived mate value was unrelated to men's facial attractiveness as rated by women. Men who believed they were of high mate value were more likely than lower mate value men to prefer to marry at a younger age; to have a spouse who was younger than them; and to have a partner who was sociable, ambitious, high in social status, with good financial prospects, a desire for children, health, good looks, and mutual attraction. Objective male facial attractiveness was generally unrelated to heightened mate preferences, with the exception of heightened preference for similar religious background and good physical health. Findings suggest that men who perceive themselves as high in overall mate value are selective in their mate choice in a manner similar to high mate value women.

  10. Mate Value Discrepancy and Mate Retention Behaviors of Self and Partner.

    Science.gov (United States)

    Sela, Yael; Mogilski, Justin K; Shackelford, Todd K; Zeigler-Hill, Virgil; Fink, Bernhard

    2017-10-01

    This study investigated the relationship between perceived mate value discrepancy (i.e., the difference between an individual's mate value and their partner's mate value) and perceived frequency of mate retention performed by an individual relative to his or her partner. In two studies, participants in long-term, exclusive, sexual, heterosexual relationships reported their own, and their partner's, mate value and mate retention. Samples included 899 community members (Study 1) and 941 students and community members (Study 2). In Study 1, we documented that individuals with higher self-perceived short-term mate value, and who perceive their partner to have lower (vs. higher) short-term mate value, perform less frequent Benefit-Provisioning mate retention, controlling for the partner's Benefit-Provisioning mate retention. In Study 2, we documented that individuals who perceive that they could less easily replace their partner, and who perceive their partner could more (vs. less) easily replace them, perform more frequent mate retention (Benefit-Provisioning and Cost-Inflicting), controlling for the partner's mate retention. These results highlight the importance of assessing perceived discrepancies in mate value (notably, regarding the replaceability of self and partner with another long-term mate) and perceived mate retention behaviors of self, relative to partner, between men and women in long-term relationships. © 2016 Wiley Periodicals, Inc.

  11. Corticotropin-releasing factor critical for zebrafish camouflage behavior is regulated by light and sensitive to ethanol.

    Science.gov (United States)

    Wagle, Mahendra; Mathur, Priya; Guo, Su

    2011-01-05

    The zebrafish camouflage response is an innate "hard-wired" behavior that offers an excellent opportunity to explore neural circuit assembly and function. Moreover, the camouflage response is sensitive to ethanol, making it a tractable system for understanding how ethanol influences neural circuit development and function. Here we report the identification of corticotropin-releasing factor (CRF) as a critical component of the camouflage response pathway. We further show that ethanol, having no direct effect on the visual sensory system or the melanocytes, acts downstream of retinal ganglion cells and requires the CRF-proopiomelanocortin pathway to exert its effect on camouflage. Treatment with ethanol, as well as alteration of light exposure that changes sensory input into the camouflage circuit, robustly modifies CRF expression in subsets of neurons. Activity of both adenylyl cyclase 5 and extracellular signal-regulated kinase (ERK) is required for such ethanol-induced or light-induced plasticity of crf expression. These results reveal an essential role of a peptidergic pathway in camouflage that is regulated by light and influenced by ethanol at concentrations relevant to abuse and anxiolysis, in a cAMP-dependent and ERK-dependent manner. We conclude that this ethanol-modulated camouflage response represents a novel and relevant system for molecular genetic dissection of a neural circuit that is regulated by light and sensitive to ethanol.

  12. Mate attraction, retention and expulsion.

    Science.gov (United States)

    Miner, Emily J; Shackelford, Todd K

    2010-02-01

    Sexual selection theory and parental investment theory have guided much of the evolutionary psychological research on human mating. Based on these theories, researchers have predicted and found sex differences in mating preferences and behaviors. Men generally prefer that their long-term partners are youthful and physically attractive. Women generally prefer that their long-term partners have existing resources or clear potential for securing resources and display a willingness to invest those resources in children the relationship might produce. Both men and women, however, desire long-term partners who are kind and intelligent. Once a partner is obtained, men and women act in sex-specific ways to ensure the continuation and exclusivity of the relationship. Men, in particular, engage in behaviors designed to prevent, correct, and anticipate their partner's sexual infidelity. Relationships dissolve for evolutionarily-relevant reasons: infidelity, childlessness, and infertility. The discussion addresses directions for future research.

  13. Females use self-referent cues to avoid mating with previous mates.

    Science.gov (United States)

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-12-07

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry.

  14. Camouflage and individual variation in shore crabs (Carcinus maenas from different habitats.

    Directory of Open Access Journals (Sweden)

    Martin Stevens

    Full Text Available Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas, a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat. We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile. Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this.

  15. Perception of visual texture and the expression of disruptive camouflage by the cuttlefish, Sepia officinalis

    Science.gov (United States)

    Kelman, E.J; Baddeley, R.J; Shohet, A.J; Osorio, D

    2007-01-01

    Juvenile cuttlefish (Sepia officinalis) camouflage themselves by changing their body pattern according to the background. This behaviour can be used to investigate visual perception in these molluscs and may also give insight into camouflage design. Edge detection is an important aspect of vision, and here we compare the body patterns that cuttlefish produced in response to checkerboard backgrounds with responses to backgrounds that have the same spatial frequency power spectrum as the checkerboards, but randomized spatial phase. For humans, phase randomization removes visual edges. To describe the cuttlefish body patterns, we scored the level of expression of 20 separate pattern ‘components’, and then derived principal components (PCs) from these scores. After varimax rotation, the first component (PC1) corresponded closely to the so-called disruptive body pattern, and the second (PC2) to the mottle pattern. PC1 was predominantly expressed on checkerboards, and PC2 on phase-randomized backgrounds. Thus, cuttlefish probably have edge detectors that control the expression of disruptive pattern. Although the experiments used unnatural backgrounds, it seems probable that cuttlefish display disruptive camouflage when there are edges in the visual background caused by discrete objects such as pebbles. We discuss the implications of these findings for our understanding of disruptive camouflage. PMID:17389219

  16. Cephalopod dynamic camouflage: bridging the continuum between background matching and disruptive coloration

    Science.gov (United States)

    Hanlon, R.T.; Chiao, C.-C.; Mäthger, L.M.; Barbosa, A.; Buresch, K.C.; Chubb, C.

    2008-01-01

    Individual cuttlefish, octopus and squid have the versatile capability to use body patterns for background matching and disruptive coloration. We define—qualitatively and quantitatively—the chief characteristics of the three major body pattern types used for camouflage by cephalopods: uniform and mottle patterns for background matching, and disruptive patterns that primarily enhance disruptiveness but aid background matching as well. There is great variation within each of the three body pattern types, but by defining their chief characteristics we lay the groundwork to test camouflage concepts by correlating background statistics with those of the body pattern. We describe at least three ways in which background matching can be achieved in cephalopods. Disruptive patterns in cuttlefish possess all four of the basic components of ‘disruptiveness’, supporting Cott's hypotheses, and we provide field examples of disruptive coloration in which the body pattern contrast exceeds that of the immediate surrounds. Based upon laboratory testing as well as thousands of images of camouflaged cephalopods in the field (a sample is provided on a web archive), we note that size, contrast and edges of background objects are key visual cues that guide cephalopod camouflage patterning. Mottle and disruptive patterns are frequently mixed, suggesting that background matching and disruptive mechanisms are often used in the same pattern. PMID:19008200

  17. Color constrains depth in da Vinci stereopsis for camouflage but not occlusion.

    Science.gov (United States)

    Wardle, Susan G; Gillam, Barbara J

    2013-12-01

    Monocular regions that occur with binocular viewing of natural scenes can produce a strong perception of depth--"da Vinci stereopsis." They occur either when part of the background is occluded in one eye, or when a nearer object is camouflaged against a background surface in one eye's view. There has been some controversy over whether da Vinci depth is constrained by geometric or ecological factors. Here we show that the color of the monocular region constrains the depth perceived from camouflage, but not occlusion, as predicted by ecological considerations. Quantitative depth was found in both cases, but for camouflage only when the color of the monocular region matched the binocular background. Unlike previous reports, depth failed even when nonmatching colors satisfied conditions for perceptual transparency. We show that placing a colored line at the boundary between the binocular and monocular regions is sufficient to eliminate depth from camouflage. When both the background and the monocular region contained vertical contours that could be fused, some observers appeared to use fusion, and others da Vinci constraints, supporting the existence of a separate da Vinci mechanism. The results show that da Vinci stereopsis incorporates color constraints and is more complex than previously assumed.

  18. Camouflage and individual variation in shore crabs (Carcinus maenas) from different habitats.

    Science.gov (United States)

    Stevens, Martin; Lown, Alice E; Wood, Louisa E

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this.

  19. Fast Adaptive Thermal Camouflage Based on Flexible VO₂/Graphene/CNT Thin Films.

    Science.gov (United States)

    Xiao, Lin; Ma, He; Liu, Junku; Zhao, Wei; Jia, Yi; Zhao, Qiang; Liu, Kai; Wu, Yang; Wei, Yang; Fan, Shoushan; Jiang, Kaili

    2015-12-09

    Adaptive camouflage in thermal imaging, a form of cloaking technology capable of blending naturally into the surrounding environment, has been a great challenge in the past decades. Emissivity engineering for thermal camouflage is regarded as a more promising way compared to merely temperature controlling that has to dissipate a large amount of excessive heat. However, practical devices with an active modulation of emissivity have yet to be well explored. In this letter we demonstrate an active cloaking device capable of efficient thermal radiance control, which consists of a vanadium dioxide (VO2) layer, with a negative differential thermal emissivity, coated on a graphene/carbon nanotube (CNT) thin film. A slight joule heating drastically changes the emissivity of the device, achieving rapid switchable thermal camouflage with a low power consumption and excellent reliability. It is believed that this device will find wide applications not only in artificial systems for infrared camouflage or cloaking but also in energy-saving smart windows and thermo-optical modulators.

  20. Reducing Sand Fly Numbers in Leishmania Endemic Regions in Kenya with Insecticide Treated Camouflage Screening

    Science.gov (United States)

    Current US military operations in deserts face persistent threats from sand flies that transmit human Leishmania. Methods to reduce the risk of human infection from leishmaniasis by reducing the number of sand fly vectors were investigated in Kenya. Bifenthrin treated and un-treated camouflage netti...

  1. Relative advantages of dichromatic and trichromatic color vision in camouflage breaking.

    Science.gov (United States)

    Troscianko, Jolyon; Wilson-Aggarwal, Jared; Griffiths, David; Spottiswoode, Claire N; Stevens, Martin

    2017-01-01

    There is huge diversity in visual systems and color discrimination abilities, thought to stem from an animal's ecology and life history. Many primate species maintain a polymorphism in color vision, whereby most individuals are dichromats but some females are trichromats, implying that selection sometimes favors dichromatic vision. Detecting camouflaged prey is thought to be a task where dichromatic individuals could have an advantage. However, previous work either has not been able to disentangle camouflage detection from other ecological or social explanations, or did not use biologically relevant cryptic stimuli to test this hypothesis under controlled conditions. Here, we used online "citizen science" games to test how quickly humans could detect cryptic birds (incubating nightjars) and eggs (of nightjars, plovers and coursers) under trichromatic and simulated dichromatic viewing conditions. Trichromats had an overall advantage, although there were significant differences in performance between viewing conditions. When searching for consistently shaped and patterned adult nightjars, simulated dichromats were more heavily influenced by the degree of pattern difference than were trichromats, and were poorer at detecting prey with inferior pattern and luminance camouflage. When searching for clutches of eggs-which were more variable in appearance and shape than the adult nightjars-the simulated dichromats learnt to detect the clutches faster, but were less sensitive to subtle luminance differences. These results suggest there are substantial differences in the cues available under viewing conditions that simulate different receptor types, and that these interact with the scene in complex ways to affect camouflage breaking.

  2. For the Classroom--The Five Signs of Death: Cold Water Camouflage.

    Science.gov (United States)

    Lin, Leslie

    1981-01-01

    Outlines a classroom science activity suitable for elementary through adult levels demonstrating that coldwater submergence may cause some people to appear dead when they are not. Includes a description of several activities which exhibit the signs of coldwater camouflage, materials needed, and discussion topics. (DS)

  3. A review of visual perception mechanisms that regulate rapid adaptive camouflage in cuttlefish.

    Science.gov (United States)

    Chiao, Chuan-Chin; Chubb, Charles; Hanlon, Roger T

    2015-09-01

    We review recent research on the visual mechanisms of rapid adaptive camouflage in cuttlefish. These neurophysiologically complex marine invertebrates can camouflage themselves against almost any background, yet their ability to quickly (0.5-2 s) alter their body patterns on different visual backgrounds poses a vexing challenge: how to pick the correct body pattern amongst their repertoire. The ability of cuttlefish to change appropriately requires a visual system that can rapidly assess complex visual scenes and produce the motor responses-the neurally controlled body patterns-that achieve camouflage. Using specifically designed visual backgrounds and assessing the corresponding body patterns quantitatively, we and others have uncovered several aspects of scene variation that are important in regulating cuttlefish patterning responses. These include spatial scale of background pattern, background intensity, background contrast, object edge properties, object contrast polarity, object depth, and the presence of 3D objects. Moreover, arm postures and skin papillae are also regulated visually for additional aspects of concealment. By integrating these visual cues, cuttlefish are able to rapidly select appropriate body patterns for concealment throughout diverse natural environments. This sensorimotor approach of studying cuttlefish camouflage thus provides unique insights into the mechanisms of visual perception in an invertebrate image-forming eye.

  4. The Supergalactic Habitable Zone

    Science.gov (United States)

    Mason, Paul

    2018-01-01

    Habitability in the local universe is examined. Constrained by metal abundance and exposure to sterilizing events, life as we know it requires significantly long periods of stable environmental conditions. Planets within galaxies undergoing major mergers, active AGN, starburst episodes, and merging black holes pose serious threats to long-term habitability. Importantly, the development of several layers of protection from high-energy particles such as a thick atmosphere, a strong planetary magnetic field, an astrosphere, and a galactic magnetic field is of great benefit. Factors such as star type and activity, planet type and composition, the location of a planet within its host galaxy, and even the location within a supercluster of galaxies can affect the potential habitability of planets. We discuss the concept of the Supergalactic Habitable Zone introduced by Mason and Biermann in terms of habitability in the local universe and find that galaxies near the center of the Virgo cluster, for example, have a much lower probability for the development of life as we know it as compared to locations in the Milky Way.

  5. The Criteria of Love: Trait Desirability of Filipino Youth on Mate Selection

    Directory of Open Access Journals (Sweden)

    Racidon P. Bernarte

    2016-08-01

    Full Text Available In choosing a life partner, making a ‘good match’ is what everyone hopes for. Usually we have the habit of thinking on how many potential mates are sitting around? And with that, how many would you be attracted and attached to, and how many person you’d probably never date? To find out the relevance of the claim, this quantitative study was designed to know the desirable traits being considered by the Filipino youth in selecting their potential mate, and how male and female differ in their preferences. A total of 400 Filipino university students with the age of 15 to 23 years old participated in the study through self-administered survey. General findings revealed that over the 6 trait dimensions: Physical Traits; Social Traits; Personality Traits; Skills; Achievements; and Spiritual Traits—male and female have significant difference in their trait preference in choosing their mate. Though there are traits that fall under the same degree of importance, women still have higher preference in mate selection criteria as compared to men in all traits. Overall, the trait preferences of the respondents were critically influenced by their sex. Nevertheless, this study clearly suggests the similarity that men and women put importance to traits which can help them develop and maintain an intimate and strong interpersonal relationship with their mate.

  6. A Practical Approach in Performing the Particle Size Analysis of a Camouflage Coating Utilizing Laser-Light Scattering Technology

    National Research Council Canada - National Science Library

    Patterson, Phillip

    2000-01-01

    .... Army Research Laboratory (ARL), Aberdeen Proving Ground (APG), MD. The focus of the work centers on the instrument setup and operation for performing particle size determinations on a polydispersed, camouflage paint conforming to the U.S...

  7. Allochronic separation versus mate choice: nonrandom patterns of mating between fall armyworm host strains

    NARCIS (Netherlands)

    Schöfl, G.; Dill, A.; Heckel, D.G.; Groot, A.T.

    2011-01-01

    Assortative mating may result from intrinsic individual mating preferences or from assortment traits not requiring expression of preferences. Assortment traits are phenotypes expressed in both sexes that enhance the probability of encountering individuals possessing similar trait values. In the

  8. Miniplate-Aided Mandibular Dentition Distalization as a Camouflage Treatment of a Class III Malocclusion in an Adult

    Directory of Open Access Journals (Sweden)

    Zaki Hakami

    2018-01-01

    Full Text Available This case report describes orthodontic camouflage treatment for a 32-year-old African American male patient with Class III malocclusion. The treatment included nonextraction, nonsurgical orthodontic camouflage by en masse distalization of the mandibular teeth using skeletal anchorage devices. The total treatment time was 23 months. Normal overjet and overbite with Class I occlusion were obtained despite the compensated dentition to the skeletal malocclusion. His smile esthetics was significantly improved at the completion of his treatment.

  9. Miniplate-Aided Mandibular Dentition Distalization as a Camouflage Treatment of a Class III Malocclusion in an Adult.

    Science.gov (United States)

    Hakami, Zaki; Chen, Po Jung; Ahmida, Ahmad; Janakiraman, Nandakumar; Uribe, Flavio

    2018-01-01

    This case report describes orthodontic camouflage treatment for a 32-year-old African American male patient with Class III malocclusion. The treatment included nonextraction, nonsurgical orthodontic camouflage by en masse distalization of the mandibular teeth using skeletal anchorage devices. The total treatment time was 23 months. Normal overjet and overbite with Class I occlusion were obtained despite the compensated dentition to the skeletal malocclusion. His smile esthetics was significantly improved at the completion of his treatment.

  10. Il camouflage nel campo allargato. Variazioni su Disruptive Pattern Material e Dazzle Painting nella cultura visiva contemporanea

    OpenAIRE

    Maite Méndez Baiges

    2016-01-01

    The First World War was the scenario that led to the invention and systematic use of military camouflage techniques. Between them, the two fundamental modes of static or pictorial camouflage: mimetic, known as Disruptive Pattern Material, and the naval, called Dazzle Painting. Avantgarde artists contributed to their birth. Immediately, there was the transfer of these techniques to the civilian sphere, revealing that its essentially practical essence did not prevent the exploitation of its aes...

  11. Honey bee queens do not count mates to assess their mating success

    Science.gov (United States)

    The mating system of honey bees (genus Apis) is extremely polyandrous, where reproductive females (queens) typically mate with 12 or more males (drones) during their mating flight(s). The evolutionary implications for hyperpolyandry have been subject to considerable debate and empirical testing beca...

  12. Mate preferences do predict attraction and choices in the early stages of mate selection.

    Science.gov (United States)

    Li, Norman P; Yong, Jose C; Tov, William; Sng, Oliver; Fletcher, Garth J O; Valentine, Katherine A; Jiang, Yun F; Balliet, Daniel

    2013-11-01

    Although mate preference research has firmly established that men value physical attractiveness more than women do and women value social status more than men do, recent speed-dating studies have indicated mixed evidence (at best) for whether people's sex-differentiated mate preferences predict actual mate choices. According to an evolutionary, mate preference priority model (Li, Bailey, Kenrick, & Linsenmeier, 2002; Li & Kenrick, 2006; Li, Valentine, & Patel, 2011), the sexes are largely similar in what they ideally like, but for long-term mates, they should differ on what they most want to avoid in early selection contexts. Following this model, we conducted experiments using online messaging and modified speed-dating platforms. Results indicate that when a mating pool includes people at the low end of social status and physical attractiveness, mate choice criteria are sex-differentiated: Men, more than women, chose mates based on physical attractiveness, whereas women, more than men, chose mates based on social status. In addition, individuals who more greatly valued social status or physical attractiveness on paper valued these traits more in their actual choices. In particular, mate choices were sex-differentiated when considering long-term relationships but not short-term ones, where both sexes shunned partners with low physical attractiveness. The findings validate a large body of mate preferences research and an evolutionary perspective on mating, and they have implications for research using speed-dating and other interactive contexts. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  13. Pollinators' mating rendezvous and the evolution of floral advertisement.

    Science.gov (United States)

    Fishman, Michael A; Hadany, Lilach

    2013-01-07

    Successful cross-fertilization in plant species that rely on animal pollinators depends not just on the number of pollinator visits, but also on these visits' duration. Furthermore, in non-deceptive pollination, a visit's duration depends on the magnitude of the reward provided to the pollinator. Accordingly, plants that rely on biotic pollination have to partition their investment in cross-fertilization assurance between attracting pollinator visits - advertisement, and rewarding visitors to assure that the visit is of productive duration. Here we analyze these processes by a combination of optimality methods and game theoretical modeling. Our results indicate that the optimality in such allocation of resources depends on the types of reward offered to the pollinators. More precisely, we show that plants that offer both food reward and mating rendezvous to pollinators will evolve to allocate a higher proportion of their cross-fertilization assurance budget to advertisement than plants that offer only food reward. That is, our results indicate that pollinators' mating habits may play a role in floral evolution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Trajectories of martian habitability.

    Science.gov (United States)

    Cockell, Charles S

    2014-02-01

    Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments.

  15. Habit and context

    DEFF Research Database (Denmark)

    Mueller Loose, Simone; Jaeger, S. R.

    , but like the influence of context, quantification of its importance is lacking. To contribute to a closing of this gap, we analyse food dairy data from 100+ New Zealand consumers quantitatively with a variance component analysis. Food diaries, recording the eating occasion, beverages and meal food...... was used to examine the contribution of context factors (eating occasion, where, with whom), habit (share of beverage in consumption portfolio) and socio-demographic characteristics (gender, age) to explain the binary choice of seven main beverage types (water, hot beverages, milk, carbonated beverages...... predictor for its consumption likelihood. The impact of this measure for habit differed across beverages, for instance it played a larger role for hot beverages and water than for the consumption of beer and wine. Eating occasions and its interaction with place of consumption had highest explanatory power...

  16. Previous experiences shape adaptive mate preferences

    NARCIS (Netherlands)

    Fawcett, Tim W.; Bleay, Colin

    2009-01-01

    Existing models of mate choice assume that individuals have perfect knowledge of their own ability to attract a mate and can adjust their preferences accordingly. However, real animals will typically be uncertain of their own attractiveness. A potentially useful source of information on this is the

  17. New directions for mating disruption in Wisconsin

    Science.gov (United States)

    Mating Disruption (MD) is an alternative to insecticide for control of three major pests -Sparganthois fruitworm, Cranberry fruitworm and Blackheaded fireworm. MD functions by sending out false plumes of the insect's sex pheromones – this interferes with the insect’s ability to find a mate, preempti...

  18. Smoking habits of nurses

    Directory of Open Access Journals (Sweden)

    E. Jacka

    1984-09-01

    Full Text Available There is little debate as to the harmful effects of cigarette smoking on health. Most health workers advise their patients to cease the practice. The impact of the advice is however diluted if it is seen to be ignored by the professionals themselves. As nurses play an increasing role in all levels of health care a survey was undertaken to investigate the smoking habits of two groups of nurses - those operating within the community and those working in institutions.

  19. Effective Physics Study Habits

    Science.gov (United States)

    Zettili, Nouredine

    2011-04-01

    We discuss the methods of efficient study habits and how they can be used by students to help them improve learning physics. In particular, we deal with ideas pertaining to the most effective techniques needed to help students improve their physics study skills. These ideas were developed as part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), an outreach grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. In the presentation, focus on topics such as the skills of how to develop long term memory, how to improve concentration power, how to take class notes, how to prepare for and take exams, how to study scientific subjects such as physics. We argue that the student who conscientiously uses the methods of efficient study habits will be able to achieve higher results than the student who does not; moreover, a student equipped with the proper study skills will spend much less time to learn a subject than a student who has no good study habits. The underlying issue here is not the quantity of time allocated to the study efforts by the student, but the efficiency and quality of actions. This work is supported by the Alabama Commission on Higher Education as part of IMPACTSEED grant.

  20. Camouflage therapy workshop for pediatric dermatology patients: a review of 6 cases.

    Science.gov (United States)

    Padilla-España, L; del Boz, J; Ramírez-López, M B; Fernández-Sánchez, M E

    2014-06-01

    Certain skin conditions, such as vitiligo, acne, vascular malformations, and surgical scars, can impair the quality of life of pediatric patients, especially adolescents-even to the point of hindering psychosocial development. We review the cases of 6 patients with discoloration or scarring, predominantly of the face, who attended our cosmetic camouflage workshops from January through December 2012. The quality-of-life impact of their skin disorder was assessed before and after workshop attendance. Cosmetic camouflage is an easily replicated, cheap, and noninvasive adjunctive treatment of great potential value in managing skin conditions that impair the physical and emotional well-being of pediatric patients. Copyright © 2013 Elsevier España, S.L. y AEDV. All rights reserved.

  1. Selected issues connected with determination of requirements of spectral properties of camouflage patterns

    Science.gov (United States)

    Racek, František; Jobánek, Adam; Baláž, Teodor; Krejčí, Jaroslav

    2017-10-01

    Traditionally spectral reflectance of the material is measured and compared with permitted spectral reflectance boundaries. The boundaries are limited by upper and lower curve of spectral reflectance. The boundaries for unique color has to fulfil the operational requirements as a versatility of utilization through the all year seasons, day and weather condition on one hand and chromatic and spectral matching with background as well as the manufacturability on the other hand. The interval between the boundaries suffers with ambivalent feature. Camouflage pattern producer would be happy to see it much wider, but blending effect into its particular background could be better with narrower tolerance limits. From the point of view of long time user of camouflage pattern battledress, there seems to be another ambivalent feature. Width of the tolerance zone reflecting natural dispersion of spectral reflectance values allows the significant distortions of shape of the spectral curve inside the given boundaries.

  2. Stretchable surfaces with programmable 3D texture morphing for synthetic camouflaging skins

    Science.gov (United States)

    Pikul, J. H.; Li, S.; Bai, H.; Hanlon, R. T.; Cohen, I.; Shepherd, R. F.

    2017-10-01

    Technologies that use stretchable materials are increasingly important, yet we are unable to control how they stretch with much more sophistication than inflating balloons. Nature, however, demonstrates remarkable control of stretchable surfaces; for example, cephalopods can project hierarchical structures from their skin in milliseconds for a wide range of textural camouflage. Inspired by cephalopod muscular morphology, we developed synthetic tissue groupings that allowed programmable transformation of two-dimensional (2D) stretchable surfaces into target 3D shapes. The synthetic tissue groupings consisted of elastomeric membranes embedded with inextensible textile mesh that inflated to within 10% of their target shapes by using a simple fabrication method and modeling approach. These stretchable surfaces transform from flat sheets to 3D textures that imitate natural stone and plant shapes and camouflage into their background environments.

  3. Bio-camouflage of anatase nanoparticles explored by in situ high-resolution electron microscopy.

    Science.gov (United States)

    Ribeiro, Ana R; Mukherjee, Arijita; Hu, Xuan; Shafien, Shayan; Ghodsi, Reza; He, Kun; Gemini-Piperni, Sara; Wang, Canhui; Klie, Robert F; Shokuhfar, Tolou; Shahbazian-Yassar, Reza; Borojevic, Radovan; Rocha, Luis A; Granjeiro, José M

    2017-08-03

    While titanium is the metal of choice for most prosthetics and inner body devices due to its superior biocompatibility, the discovery of Ti-containing species in the adjacent tissue as a result of wear and corrosion has been associated with autoimmune diseases and premature implant failures. Here, we utilize the in situ liquid cell transmission electron microscopy (TEM) in a liquid flow holder and graphene liquid cells (GLCs) to investigate, for the first time, the in situ nano-bio interactions between titanium dioxide nanoparticles and biological medium. This imaging and spectroscopy methodology showed the process of formation of an ionic and proteic bio-camouflage surrounding Ti dioxide (anatase) nanoparticles that facilitates their internalization by bone cells. The in situ understanding of the mechanisms of the formation of the bio-camouflage of anatase nanoparticles may contribute to the definition of strategies aimed at the manipulation of these NPs for bone regenerative purposes.

  4. A Terminal Guidance Law Based on Motion Camouflage Strategy of Air-to-Ground Missiles

    Directory of Open Access Journals (Sweden)

    Chang-sheng Gao

    2016-01-01

    Full Text Available A guidance law for attacking ground target based on motion camouflage strategy is proposed in this paper. According to the relative position between missile and target, the dual second-order dynamics model is derived. The missile guidance condition is given by analyzing the characteristic of motion camouflage strategy. Then, the terminal guidance law is derived by using the relative motion of missile and target and the guidance condition. In the process of derivation, the three-dimensional guidance law could be designed in a two-dimensional plane and the difficulty of guidance law design is reduced. A two-dimensional guidance law for three-dimensional space is derived by bringing the estimation for target maneuver. Finally, simulation for the proposed guidance law is taken and compared with pure proportional navigation. The simulation results demonstrate that the proposed guidance law can be applied to air-to-ground missiles.

  5. Age Variation in Mating Strategies and Mate Preferences: Beliefs versus Reality

    Directory of Open Access Journals (Sweden)

    April Bleske-Rechek

    2009-04-01

    Full Text Available We conducted three studies to (1 investigate individuals' beliefs about change in mating desires over the course of emerging adulthood and (2 determine whether those beliefs reflect actual variation in mating desires among emerging adults of varied ages (late teens through twenties. In Study 1, 103 men and women gave their thoughts on how college students change, if at all, in what they most desire in a relationship and relationship partner as they move from being incoming freshmen to graduating seniors. In Studies 2 and 3, using a college sample and then an internet sample (n s = 288 and 307, men and women between the ages of 18 and 26 completed mating strategies inventories and allotted a limited number of “mate dollars” to 10 mate characteristics. Findings suggest that although emerging adults believe that their peers' mating desires change systematically over time, emerging adults' self-reported mating desires vary little with age.

  6. Camouflage treatment of skeletal Class III malocclusion with conventional orthodontic therapy.

    Science.gov (United States)

    Park, Jae Hyun; Yu, Joseph; Bullen, Ryan

    2017-04-01

    Nonextraction camouflage treatment along with Class III elastics was used to treat a 39-year-old woman with a skeletal Class III pattern and a low mandibular plane angle and short lower anterior facial height. The total active treatment time was 26 months. Her occlusion, smile esthetics, and soft tissue profile were significantly improved after treatment. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  7. Camouflage Traffic: Minimizing Message Delay for Smart Grid Applications Under Jamming

    Science.gov (United States)

    2015-01-16

    communications for SCADA sys- tems,” Pipeline and Gas J., vol. 238, Feb. 2011, pp. 1–6. [19] T. S. Sidhu and Y. Yin, “Modelling and simulation for perfor...Camouflage Traffic: Minimizing Message Delay for Smart Grid Applications under Jamming Zhuo Lu, Student Member, IEEE, Wenye Wang, Senior Member, IEEE...spread spectrum systems, which provide jamming resilience via multiple frequency and code channels, must be adapted to the smart grid for secure

  8. Dazzle camouflage and the confusion effect: the influence of varying speed on target tracking.

    Science.gov (United States)

    Hogan, Benedict G; Cuthill, Innes C; Scott-Samuel, Nicholas E

    2017-01-01

    The formation of groups is a common strategy to avoid predation in animals, and recent research has indicated that there may be interactions between some forms of defensive coloration, notably high-contrast 'dazzle camouflage', and one of the proposed benefits of grouping: the confusion effect. However, research into the benefits of dazzle camouflage has largely used targets moving with constant speed. This simplification may not generalize well to real animal systems, where a number of factors influence both within- and between-individual variation in speed. Departure from the speed of your neighbours in a group may be predicted to undermine the confusion effect. This is because individual speed may become a parameter through which the observer can individuate otherwise similar targets: an 'oddity effect'. However, dazzle camouflage patterns are thought to interfere with predator perception of speed and trajectory. The current experiment investigated the possibility that such patterns could ameliorate the oddity effect caused by within-group differences in prey speed. We found that variation in speed increased the ease with which participants could track targets in all conditions. However, we found no evidence that motion dazzle camouflage patterns reduced oddity effects based on this variation in speed, a result that may be informative about the mechanisms behind this form of defensive coloration. In addition, results from those conditions most similar to those of published studies replicated previous results, indicating that targets with stripes parallel to the direction of motion are harder to track, and that this pattern interacts with the confusion effect to a greater degree than background matching or orthogonal-to-motion striped patterns.

  9. Computational mate choice: theory and empirical evidence.

    Science.gov (United States)

    Castellano, Sergio; Cadeddu, Giorgia; Cermelli, Paolo

    2012-06-01

    The present review is based on the thesis that mate choice results from information-processing mechanisms governed by computational rules and that, to understand how females choose their mates, we should identify which are the sources of information and how they are used to make decisions. We describe mate choice as a three-step computational process and for each step we present theories and review empirical evidence. The first step is a perceptual process. It describes the acquisition of evidence, that is, how females use multiple cues and signals to assign an attractiveness value to prospective mates (the preference function hypothesis). The second step is a decisional process. It describes the construction of the decision variable (DV), which integrates evidence (private information by direct assessment), priors (public information), and value (perceived utility) of prospective mates into a quantity that is used by a decision rule (DR) to produce a choice. We make the assumption that females are optimal Bayesian decision makers and we derive a formal model of DV that can explain the effects of preference functions, mate copying, social context, and females' state and condition on the patterns of mate choice. The third step of mating decision is a deliberative process that depends on the DRs. We identify two main categories of DRs (absolute and comparative rules), and review the normative models of mate sampling tactics associated to them. We highlight the limits of the normative approach and present a class of computational models (sequential-sampling models) that are based on the assumption that DVs accumulate noisy evidence over time until a decision threshold is reached. These models force us to rethink the dichotomy between comparative and absolute decision rules, between discrimination and recognition, and even between rational and irrational choice. Since they have a robust biological basis, we think they may represent a useful theoretical tool for

  10. Escape Distance in Ground-Nesting Birds Differs with Individual Level of Camouflage.

    Science.gov (United States)

    Wilson-Aggarwal, Jared K; Troscianko, Jolyon T; Stevens, Martin; Spottiswoode, Claire N

    2016-08-01

    Camouflage is one of the most widespread antipredator strategies in the animal kingdom, yet no animal can match its background perfectly in a complex environment. Therefore, selection should favor individuals that use information on how effective their camouflage is in their immediate habitat when responding to an approaching threat. In a field study of African ground-nesting birds (plovers, coursers, and nightjars), we tested the hypothesis that individuals adaptively modulate their escape behavior in relation to their degree of background matching. We used digital imaging and models of predator vision to quantify differences in color, luminance, and pattern between eggs and their background, as well as the plumage of incubating adult nightjars. We found that plovers and coursers showed greater escape distances when their eggs were a poorer pattern match to the background. Nightjars sit on their eggs until a potential threat is nearby, and, correspondingly, they showed greater escape distances when the pattern and color match of the incubating adult's plumage-rather than its eggs-was a poorer match to the background. Finally, escape distances were shorter in the middle of the day, suggesting that escape behavior is mediated by both camouflage and thermoregulation.

  11. Daytime eyeshine contributes to pupil camouflage in a cryptobenthic marine fish.

    Science.gov (United States)

    Santon, Matteo; Bitton, Pierre-Paul; Harant, Ulrike K; Michiels, Nico K

    2018-05-09

    Ocular reflectors enhance eye sensitivity in dim light, but can produce reflected eyeshine when illuminated. Some fish can occlude their reflectors during the day. The opposite is observed in cryptic sit-and-wait predators such as scorpionfish and toadfish, where reflectors are occluded at night and exposed during the day. This results in daytime eyeshine, proposed to enhance pupil camouflage by reducing the contrast between the otherwise dark pupil and the surrounding tissue. In this study, we test this hypothesis in the scorpionfish Scorpaena porcus and show that eyeshine is the result of two mechanisms: the previously described Stratum Argenteum Reflected (SAR) eyeshine, and Pigment Epithelium Transmitted (PET) eyeshine, a newly described mechanism for this species. We confirm that the ocular reflector is exposed only when the eye is light-adapted, and present field measurements to show that eyeshine reduces pupil contrast against the iris. We then estimate the relative contribution of SAR and PET eyeshine to pupil brightness. Visual models for different light scenarios in the field show that daytime eyeshine enhances pupil camouflage from the perspective of a prey fish. We propose that the reversed occlusion mechanism of some cryptobenthic predators has evolved as a compromise between camouflage and vision.

  12. Quality of life in pediatric patients before and after cosmetic camouflage of visible skin conditions.

    Science.gov (United States)

    Ramien, Michele L; Ondrejchak, Sandra; Gendron, Roxanne; Hatami, Afshin; McCuaig, Catherine C; Powell, Julie; Marcoux, Danielle

    2014-11-01

    Visible vascular and pigmentary conditions have a negative impact on children's and adolescents' quality of life (QoL). We sought to quantitate the effect of visible skin anomalies and their camouflage on QoL. In all, 41 patients, 5 years of age and older, were taught to use cosmetic camouflage. QoL was assessed using the Children's Dermatology Life Quality Index (CDLQI) before and 6 months after the intervention. Satisfaction and use were evaluated after 1 and 6 months. Baseline QoL scores revealed a small impact of vascular anomalies (CDLQI score 4.2) and a small to moderate effect of pigmentary anomalies (CDLQI score 6.1). Six months after the intervention, QoL improved in the study population as a whole (CDLQI score 5.1 vs 2.1, Pcamouflage was well tolerated and patients with pigmentary anomalies were more likely to continue using the products. Limitations include small study population, few male patients, cultural influences not addressed, and limited range of conditions. Children and teenagers with visible vascular and pigmentary anomalies experience an impairment of QoL that is abrogated by introduction to use of cosmetic camouflage. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  13. Divergence in cryptic leaf colour provides local camouflage in an alpine plant.

    Science.gov (United States)

    Niu, Yang; Chen, Zhe; Stevens, Martin; Sun, Hang

    2017-10-11

    The efficacy of camouflage through background matching is highly environment-dependent, often resulting in intraspecific colour divergence in animals to optimize crypsis in different visual environments. This phenomenon is largely unexplored in plants, although several lines of evidence suggest they do use crypsis to avoid damage by herbivores. Using Corydalis hemidicentra, an alpine plant with cryptic leaf colour, we quantified background matching between leaves and surrounding rocks in five populations based on an approximate model of their butterfly enemy's colour perception. We also investigated the pigment basis of leaf colour variation and the association between feeding risk and camouflage efficacy. We show that plants exhibit remarkable colour divergence between populations, consistent with differences in rock appearances. Leaf colour varies because of a different quantitative combination of two basic pigments-chlorophyll and anthocyanin-plus different air spaces. As expected, leaf colours are better matched against their native backgrounds than against foreign ones in the eyes of the butterfly. Furthermore, improved crypsis tends to be associated with a higher level of feeding risk. These results suggest that divergent cryptic leaf colour may have evolved to optimize local camouflage in various visual environments, extending our understanding of colour evolution and intraspecific phenotype diversity in plants. © 2017 The Author(s).

  14. The mating behavior of Iguana iguana

    Science.gov (United States)

    Rodda, G.H.

    1992-01-01

    Over a 19 month period I observed the social behaviors of individually recognized green iguanas, Iguana iguana, at three sites in the llanos of Venezuela. The behavior of iguanas outside the mating season differed from that seen during the mating season in three major ways: (1) during normal waking hours outside the breeding season, adult iguanas spent the majority of time immobile, apparently resting; (2) their interactions involved fewer high intensity displays; and (3) their day to day movements were often nomadic. During the mating season, one site was watched continuously during daylight hours (iguanas sleep throughout the night), allowing a complete count of all copulation attempts (N = 250) and territorial interactions. At all sites, dominant males controlled access to small mating territories. Within the territories there did not appear to be any resources needed by females or their offspring. Thus, females could choose mates directly on the basis of male phenotype. Females aggregated in the mating territories of the largest males and mated preferentially with them. Territorial males copulated only once per day, although on several occasions more than one resident female was receptive on the same day. A few small nonterritorial males exhibited pseudofemale behavior (i.e., they abstained from sexual competition), but most nonterritorial males stayed on the periphery of mating territories and attempted to force copulations on unguarded females (peripheral male behavior). Uncooperative females were mounted by as many as three males simultaneously. Females resisted 95% of the 200 observed mating attempts by peripheral males, but only 56% of the attempts by territorial males (N = 43). The selectivity of the females probably increased the genetic representation of the territorial males in the next generation. During the mating season females maintained a dominance hierarchy among themselves. Low ranked females tended to be excluded from preferred

  15. Firefly Mating Algorithm for Continuous Optimization Problems

    Directory of Open Access Journals (Sweden)

    Amarita Ritthipakdee

    2017-01-01

    Full Text Available This paper proposes a swarm intelligence algorithm, called firefly mating algorithm (FMA, for solving continuous optimization problems. FMA uses genetic algorithm as the core of the algorithm. The main feature of the algorithm is a novel mating pair selection method which is inspired by the following 2 mating behaviors of fireflies in nature: (i the mutual attraction between males and females causes them to mate and (ii fireflies of both sexes are of the multiple-mating type, mating with multiple opposite sex partners. A female continues mating until her spermatheca becomes full, and, in the same vein, a male can provide sperms for several females until his sperm reservoir is depleted. This new feature enhances the global convergence capability of the algorithm. The performance of FMA was tested with 20 benchmark functions (sixteen 30-dimensional functions and four 2-dimensional ones against FA, ALC-PSO, COA, MCPSO, LWGSODE, MPSODDS, DFOA, SHPSOS, LSA, MPDPGA, DE, and GABC algorithms. The experimental results showed that the success rates of our proposed algorithm with these functions were higher than those of other algorithms and the proposed algorithm also required fewer numbers of iterations to reach the global optima.

  16. Mate-sampling costs and sexy sons.

    Science.gov (United States)

    Kokko, H; Booksmythe, I; Jennions, M D

    2015-01-01

    Costly female mating preferences for purely Fisherian male traits (i.e. sexual ornaments that are genetically uncorrelated with inherent viability) are not expected to persist at equilibrium. The indirect benefit of producing 'sexy sons' (Fisher process) disappears: in some models, the male trait becomes fixed; in others, a range of male trait values persist, but a larger trait confers no net fitness advantage because it lowers survival. Insufficient indirect selection to counter the direct cost of producing fewer offspring means that preferences are lost. The only well-cited exception assumes biased mutation on male traits. The above findings generally assume constant direct selection against female preferences (i.e. fixed costs). We show that if mate-sampling costs are instead derived based on an explicit account of how females acquire mates, an initially costly mating preference can coevolve with a male trait so that both persist in the presence or absence of biased mutation. Our models predict that empirically detecting selection at equilibrium will be difficult, even if selection was responsible for the location of the current equilibrium. In general, it appears useful to integrate mate sampling theory with models of genetic consequences of mating preferences: being explicit about the process by which individuals select mates can alter equilibria. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  17. Computer codes for evaluation of control room habitability (HABIT)

    International Nuclear Information System (INIS)

    Stage, S.A.

    1996-06-01

    This report describes the Computer Codes for Evaluation of Control Room Habitability (HABIT). HABIT is a package of computer codes designed to be used for the evaluation of control room habitability in the event of an accidental release of toxic chemicals or radioactive materials. Given information about the design of a nuclear power plant, a scenario for the release of toxic chemicals or radionuclides, and information about the air flows and protection systems of the control room, HABIT can be used to estimate the chemical exposure or radiological dose to control room personnel. HABIT is an integrated package of several programs that previously needed to be run separately and required considerable user intervention. This report discusses the theoretical basis and physical assumptions made by each of the modules in HABIT and gives detailed information about the data entry windows. Sample runs are given for each of the modules. A brief section of programming notes is included. A set of computer disks will accompany this report if the report is ordered from the Energy Science and Technology Software Center. The disks contain the files needed to run HABIT on a personal computer running DOS. Source codes for the various HABIT routines are on the disks. Also included are input and output files for three demonstration runs

  18. Status and Mating Success Amongst Visual Artists

    Science.gov (United States)

    Clegg, Helen; Nettle, Daniel; Miell, Dorothy

    2011-01-01

    Geoffrey Miller has hypothesized that producing artwork functions as a mating display. Here we investigate the relationship between mating success and artistic success in a sample of 236 visual artists. Initially, we derived a measure of artistic success that covered a broad range of artistic behaviors and beliefs. As predicted by Miller’s evolutionary theory, more successful male artists had more sexual partners than less successful artists but this did not hold for female artists. Also, male artists with greater artistic success had a mating strategy based on longer term relationships. Overall the results provide partial support for the sexual selection hypothesis for the function of visual art. PMID:22059085

  19. Impact of Cosmetic Camouflage on the Quality of Life of Children With Skin Disease and Their Families.

    Science.gov (United States)

    Salsberg, Jennifer M; Weinstein, Miriam; Shear, Neil; Lee, Michelle; Pope, Elena

    2016-05-01

    Cosmetic camouflage is known to improve quality of life in adults. Few data are available regarding cosmetic camouflage in children, and thus it is not often selected as a mode of treatment. We sought to determine whether cosmetic camouflage leads to improved quality of life of pediatric patients with visible dermatoses and their parent or primary caregiver. Patients aged 5 to 17 years with visible skin disease and their parent were assessed with the Children's Dermatology Life Quality Index (CDLQI) and the Family Dermatology Life Quality Index (FDLQI) before and after consultation regarding cosmetic camouflage. Twenty-two children with skin conditions were included in the study. The mean CDLQI decreased from 6.82 (SD = 1.28) to 3.05 (SD = 0.65; P = .0014), while the mean FDLQI decreased from 7.68 (SD = 1.15) to 4.68 (SD = 0.92; P = .0012). Our study highlighted improvement in quality of life in patients with skin disorders who were managed with cosmetic camouflage. © The Author(s) 2015.

  20. Psychosocial effects of a skin camouflage program in female survivors with head and neck cancer: A randomized controlled trial.

    Science.gov (United States)

    Chen, Shu-Ching; Huang, Bing-Shen; Lin, Chien-Yu; Fan, Kang-Hsing; Chang, Joseph Tung-Chien; Wu, Shu-Chen; Lai, Yeur-Hur

    2017-09-01

    The purpose of this study was to evaluate the effects of a skin camouflage program on disfigurement, self-esteem, social interaction, and body image in female head and neck cancer (HNC) survivors. A prospective, repeated-measures, randomized controlled therapeutic intervention design was used. A total of 66 participants were randomly assigned to each group, with 32 in the experimental group and 34 in the control group. The experimental group received a 4-session skin camouflage program, and the control group received routine care. Patients were assessed at 3 time points: baseline assessment (T0) and then at 1, 2, and 3 months (T1, T2, and T3, respectively) after participating in the skin camouflage program. Patients in the experimental group had significantly less facial disfigurement, depression, fear of social interaction, and anxiety regarding social interaction compared with those in the control group. Participants in both groups had significantly lower levels of facial disfigurement, depression, fear of social interaction, anxiety of social interaction, and body image at the final posttest assessment than at the pretest assessment. There were no differences between the groups and within groups with respect to self-esteem. The 3-month skin camouflage program effectively improved facial disfigurement, fear of social interaction, anxiety of social interaction, and body image of female HNC survivors. A survival care plan should include a skin camouflage program to improve body image perception and decrease anxiety after treatment of HNC. Copyright © 2016 John Wiley & Sons, Ltd.

  1. SMEs’ Purchasing Habits

    Directory of Open Access Journals (Sweden)

    Emre S. Ozmen

    2014-05-01

    Full Text Available Although micro companies overpower the small and medium enterprise (SME segment, generalizations are often with medium size companies, and therefore, there are many unknowns, especially when it comes to its buying behavior. Conformist studies and industry practices assume SMEs to be “normative” or “conservative” buyers; however, this hypothesis is untested. This article aims to scrutinize the reality, and proposes a unified model that rejects pre-containerization in buying behavior typologies, as well as selectiveness in terms of audience type, whether it is corporate, SME, or consumer. While replacing researchers’ perceptions with the audience’s, the model yields actual knowledge that can lead to audience’s beliefs in lieu of the opposite, which is used to mislead stakeholders. The study shows that SMEs also buy like individuals and spend in a similar way to consumers’, including not only “normative” and “conservative” but also “negligent” and “impulse” zones. From the research-implications perspective, future studies by behaviorists can explore why SMEs purchase in this way. Marketers may benefit from the finding that SMEs buy like individuals. In addition, SMEs may want to be conscious of their purchasing habits, and—utilizing the newly introduced “risk score” frontier—policymakers should assess the consequences of these habits at the macro level.

  2. Height, Relationship Satisfaction, Jealousy, and Mate Retention

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2009-07-01

    Full Text Available Male height is associated with high mate value. In particular, tall men are perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

  3. Associations between body morphology, mating success and mate preferences among Slovak males and females.

    Science.gov (United States)

    Prokop, Pavol; Fedor, Peter

    2013-01-01

    Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

  4. Antioxidant activity of polyphenols from green and toasted mate tea.

    Science.gov (United States)

    Coentrão, Patricia de Abreu Marques; Teixeira, Valéria Laneuville; Netto, Annibal Duarte Pereira

    2011-05-01

    The production and distribution of toasted mate tea in Brazil has increased, which has resulted in its greater consumption. Mate tea is obtained by roasting non-fermented erva-mate in order to produce toasted erva-mate or toasted mate tea. However, although the product is much appreciated, studies of its chemical composition and the concentration of polyphenols, particularly flavonols present in toasted mate tea, are few and often controversial. This paper elucidates some misunderstandings involving the nomenclature of erva-mate and toasted mate, and mainly provides an overview of the composition of polyphenols and antioxidant capacity of toasted mate tea and its raw material, erva-mate, in comparison with other teas, the compositions of which were found in the literature.

  5. Red trap colour of the carnivorous plant Drosera rotundifolia does not serve a prey attraction or camouflage function.

    Science.gov (United States)

    Foot, G; Rice, S P; Millett, J

    2014-01-01

    The traps of many carnivorous plants are red in colour. This has been widely hypothesized to serve a prey attraction function; colour has also been hypothesized to function as camouflage, preventing prey avoidance. We tested these two hypotheses in situ for the carnivorous plant Drosera rotundifolia. We conducted three separate studies: (i) prey attraction to artificial traps to isolate the influence of colour; (ii) prey attraction to artificial traps on artificial backgrounds to control the degree of contrast and (iii) observation of prey capture by D. rotundifolia to determine the effects of colour on prey capture. Prey were not attracted to green traps and were deterred from red traps. There was no evidence that camouflaged traps caught more prey. For D. rotundifolia, there was a relationship between trap colour and prey capture. However, trap colour may be confounded with other leaf traits. Thus, we conclude that for D. rotundifolia, red trap colour does not serve a prey attraction or camouflage function.

  6. Breaking car use habits

    DEFF Research Database (Denmark)

    Thøgersen, John; Møller, Berit Thorup

    2008-01-01

    Based on calls for innovative ways of reducing car traffic and research indicating that car driving is often the result of habitual decision-making and choice processes, this paper reports on a field experiment designed to test a tool aimed to entice drivers to skip the habitual choice of the car...... and consider using-or at least trying-public transport instead. About 1,000 car drivers participated in the experiment either as experimental subjects, receiving a free one-month travelcard, or as control subjects. As predicted, the intervention had a significant impact on drivers' use of public transport...... and it also neutralized the impact of car driving habits on mode choice. However, in the longer run (i.e., four months after the experiment) experimental subjects did not use public transport more than control subjects. Hence, it seems that although many car drivers choose travel mode habitually, their final...

  7. Camouflage Effects of Various Colour-Marking Morphs against Different Microhabitat Backgrounds in a Polymorphic Pygmy Grasshopper Tetrix japonica

    Science.gov (United States)

    Tsurui, Kaori; Honma, Atsushi; Nishida, Takayoshi

    2010-01-01

    Background Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds), as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey). Methodology/Principal Findings Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1) do the morphs differ in the degree of crypsis in each microhabitat, 2) are different morphs most cryptic in specific backgrounds of the microhabitats, and 3) does the morph frequency reflect the degree of crypsis? Conclusions/Significance The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass), although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration

  8. Camouflage effects of various colour-marking morphs against different microhabitat backgrounds in a polymorphic pygmy grasshopper Tetrix japonica.

    Science.gov (United States)

    Tsurui, Kaori; Honma, Atsushi; Nishida, Takayoshi

    2010-07-06

    Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds), as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey). Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1) do the morphs differ in the degree of crypsis in each microhabitat, 2) are different morphs most cryptic in specific backgrounds of the microhabitats, and 3) does the morph frequency reflect the degree of crypsis? The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass), although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration and other fitness components, providing a better understanding of

  9. Camouflage effects of various colour-marking morphs against different microhabitat backgrounds in a polymorphic pygmy grasshopper Tetrix japonica.

    Directory of Open Access Journals (Sweden)

    Kaori Tsurui

    2010-07-01

    Full Text Available Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds, as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey.Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1 do the morphs differ in the degree of crypsis in each microhabitat, 2 are different morphs most cryptic in specific backgrounds of the microhabitats, and 3 does the morph frequency reflect the degree of crypsis?The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass, although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration and other fitness components, providing a better

  10. Evidence for passive chemical camouflage in the parasitic mite Varroa destructor.

    Science.gov (United States)

    Kather, Ricarda; Drijfhout, Falko P; Shemilt, Sue; Martin, Stephen J

    2015-02-01

    Social insect colonies provide a stable and safe environment for their members. Despite colonies being heavily guarded, parasites have evolved numerous strategies to invade and inhabit these hostile places. Two such strategies are (true) chemical mimicry via biosynthesis of host odor, and chemical camouflage, in which compounds are acquired from the host. The ectoparasitic mite Varroa destructor feeds on hemolymph of its honey bee host, Apis mellifera. The mite's odor closely resembles that of its host, which allows V. destructor to remain undetected as it lives on the adult host during its phoretic phase and while reproducing on the honeybee brood. During the mite life cycle, it switches between host adults and brood, which requires it to adjust its profile to mimic the very different odors of honey bee brood and adults. In a series of transfer experiments, using bee adults and pupae, we tested whether V. destructor changes its profile by synthesizing compounds or by using chemical camouflage. We show that V. destructor required direct access to host cuticle to mimic its odor, and that it was unable to synthesize host-specific compounds itself. The mite was able to mimic host odor, even when dead, indicating a passive physico-chemical mechanism of the parasite cuticle. The chemical profile of V. destructor was adjusted within 3 to 9 h after switching hosts, demonstrating that passive camouflage is a highly efficient, fast and flexible way for the mite to adapt to a new host profile when moving between different host life stages or colonies.

  11. Orthodontic camouflage versus orthognathic surgery for class III deformity: comparative cephalometric analysis.

    Science.gov (United States)

    Martinez, P; Bellot-Arcís, C; Llamas, J M; Cibrian, R; Gandia, J L; Paredes-Gallardo, V

    2017-04-01

    The objective of this study was to compare different cephalometric variables in adult patients with class III malocclusions before and after treatment, in order to determine which variables are indicative of orthodontic camouflage or orthognathic surgery. The cases of 156 adult patients were assessed: 77 treated with orthodontic camouflage and 79 treated with orthodontics and orthognathic surgery. The following cephalometric variables were measured on pre-treatment (T1) and post-treatment (T2) lateral cephalograms: sella-nasion-A-point (SNA), sella-nasion-B-point (SNB), and A-point-nasion-B-point (ANB) angles, Wits appraisal, facial axis angle, mandibular plane angle, upper and lower incisor inclination, and inter-incisal angle. There were statistically significant differences in cephalometric variables before and after treatment between the two groups. The percentage of normal pre-treatment measurements in the camouflage orthodontics group was 30.7%, which worsened slightly to 28.4% post-treatment. However in the group receiving surgery, this was 24.5% pre-treatment, improving to 33.5% after surgery. SNA, SNB, Wits appraisal, lower incisor inclination, and inter-incisal angle showed differences between the two groups before and after treatment. Wits appraisal, lower incisor inclination, and inter-incisal angle were indicative of one or other treatment. Upper and lower incisor decompensation in both groups did not reach ideal values, which impeded complete skeletal correction in 52% of surgical cases. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Habits in perioperative nursing culture.

    Science.gov (United States)

    Lindwall, Lillemor; von Post, Iréne

    2008-09-01

    This study focuses on investigating habits in perioperative nursing culture, which are often simply accepted and not normally considered or discussed. A hermeneutical approach was chosen as the means of understanding perioperative nurses' experiences of and reflections on operating theatre culture. Focus group discussions were used to collect data, which was analysed using hermeneutical text analysis. The results revealed three main categories of habits present in perioperative nursing culture: habits that promote ethical values (by temporary friendship with patients, showing respect for each other, and spending time on reflection on ethics and caring); habits that hinder progress (by seeing the patient as a surgical case, not acknowledging colleagues, and not talking about ethics); and habits that set the cultural tone (the hidden power structure and achieving more in less time).

  13. Health Habit: A Concept Analysis.

    Science.gov (United States)

    Opalinski, Andra S; Weglicki, Linda S; Gropper, Sareen S

    2018-01-01

    The aim of this article is to provide clarity of the concept of health habit. Using Walker and Avant's (1983; 2010) method for conducting a concept analysis, the authors identify the attributes and characteristics of health habit, its theoretical and practical application to nursing, and sample cases to further illustrate the concept. Empirical and conceptual literature was used to inform this concept analysis. Articles and one book from 1977 to 2014 were reviewed from PsycINFO, Medline, Cumulative Index to Nursing Health Literature (CINAHL), Science Direct, EBSCOhost and Web of Science. Offering a clear definition and conceptual model of health habit provide the foundation to identify/develop appropriate measures of the concept and guide further investigation of understanding the development and sustainability of healthy habits. Additional research is needed to test the conceptual relationships between health habits and outcome variables as they apply to different groups across the age continuum. © 2017 Wiley Periodicals, Inc.

  14. Good mates retain us right: investigating the relationship between mate retention strategies, mate value, and relationship satisfaction.

    Science.gov (United States)

    Salkicevic, Svjetlana; Stanic, Ajana L; Grabovac, Masa T

    2014-12-07

    Mate retention strategies are an important tool in keeping a partner, and their use is determined by the mate value (MV) of the partner one is trying to keep. The type of strategy used is also dependent on one's own MV: mates of lower MV are more prone to exhibiting strategies that are cost-inflicting for their partners, whereas partner-benefiting strategies are used by mates of higher value. The type of strategies used affects relationship satisfaction (RS), and is also affected by the perceived difference in MVs. However, it is unclear how someone's perception of their partner's MV is related to that partner's behavior and their own RS. To this aim, we investigated the relationship between these variables on a sample of 178 couples. Our results showed that benefit-inducing strategies were used more by--and towards--partners of higher MV, and were positively connected with RS. Cost-inflicting strategies were more used by--and towards--partners of lower MV, and were negatively connected with RS. Less MV difference was positively correlated with RS and benefiting strategies, and negatively correlated with cost-inflicting strategies. It seems that good mates use strategies that benefit their partners, which, in turn, make them more valuable and, consequently, their partner more satisfied.

  15. Psychophysics of human vision: The key to improved camouflage pattern design

    CSIR Research Space (South Africa)

    Baumbach, J

    2010-11-01

    Full Text Available determined by the factors mentioned above, but also by the (possible) observer/enemy. The human visual system (which includes the brain) is one of the most powerful observation systems. This paper examined the eye-brain interaction, and how... these properties could aid camouflage pattern development. 2. The Human Visual System The human visual system is very complex, therefore this study was undertaken in order to better understand the human eye-brain interaction. It also assisted in forming a...

  16. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 92; Issue 2. Last mated male sperm precedence in doubly mated females is not ubiquitous: evidence from sperm competition in laboratory populations of Drosophila nasuta nasuta and Drosophila nasuta albomicans. B. Shruthi S. R. Ramesh. Research Note Volume 92 Issue 2 ...

  17. Male choice of mates and mating resources in the rose bitterling (Rhodeus ocellatus)

    Czech Academy of Sciences Publication Activity Database

    Casalini, M.; Reichard, Martin; Phillips, A.; Smith, Carl

    2013-01-01

    Roč. 24, č. 5 (2013), s. 1199-1204 ISSN 1045-2249 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : body size * fecundity * male mate choice * mating system * oviposition * sperm competition * territoriality Subject RIV: EG - Zoology Impact factor: 3.157, year: 2013

  18. Evaluation of mating behaviour and mating compatibility methods for the Old World screwworm fly, Chrysomya bezziana.

    Directory of Open Access Journals (Sweden)

    April H. Wardhana

    2013-12-01

    Full Text Available The effectiveness of the Sterile Insect Technique program (SIT to eradicate pest insects relies on the success of mating competitiveness between irradiated male flies and wild type males for the wild type females. It has been successfully applied for the New World screwworm fly (NWSF, Cochliomyia hominivorax but remains unproven for the Old World screwworm fly (OWSF, Chrysomya bezziana. The aim of the study was to develop methods for investigating mating behaviour and mating compatibility of C. bezziana under laboratory conditions. Two methods were used for studying mating: individual mating (method 1 and group mating (method 2. The flies used in this study were 5-7 days old. Twenty four hours after emergence, adult flies were sexed and placed into different cages until studied. The female : male ratio in the group mating was 1 : 5 and the males were marked by painting a dot on the thorax using different oil colours. Observation of mating behaviour was investigated every 30 minutes through 10-20 replications for all methods depending on the availability of flies. Data were analysed using ANOVA and the Student’s t-test, with significance demonstrated at the 95% confidence level. The results demonstrated that the frequency of contacts between males and females at different ages was a significantly different (p 0.05 and method 2 (p > 0.05. Copulation was only initiated following longer periods of contact, mainly in the range of 270-449 seconds. The highest frequency of copulation occurred between 7-8 days, but the duration of mating was similar between 5-8 days old. The study demonstrated that the methods developed were suitable for a mating compatibility study of C. bezziana.

  19. Mate-Choice Copying in Single and Coupled Women: The Influence of Mate Acceptance and Mate Rejection Decisions of other Women

    Directory of Open Access Journals (Sweden)

    Yan Deng

    2015-01-01

    Full Text Available Studies of humans and non-human animals indicate that females tend to change the likelihood of choosing a potential mate based on the decisions of other females; this is known as mate-choice copying. In a sample of both single and coupled women, we examined the influence of other women's (model mate-choice decisions, including mate acceptance and mate rejection, on participants' attractiveness ratings of men (target and willingness of mate selection. We also examined whether different types of relationships between the target men and the model women affected mate-choice copying. We found that both the single and coupled women showed mate-choice copying, but their response patterns differed. The significant effects for single women were dependent on a decrease in attractiveness ratings when they perceived the models' mate rejection. However, the significant findings for coupled women relied on an increase in attractiveness ratings when they observed the models' mate acceptance. Furthermore, the relationship status between the target men and the model women affected the magnitude of mate-choice copying effects for the single women. Specifically, they showed less mate-choice copying when the targets and models were in a committed romantic relationship than when in a temporary relationship.

  20. A New Adaptive Hungarian Mating Scheme in Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Chanju Jung

    2016-01-01

    Full Text Available In genetic algorithms, selection or mating scheme is one of the important operations. In this paper, we suggest an adaptive mating scheme using previously suggested Hungarian mating schemes. Hungarian mating schemes consist of maximizing the sum of mating distances, minimizing the sum, and random matching. We propose an algorithm to elect one of these Hungarian mating schemes. Every mated pair of solutions has to vote for the next generation mating scheme. The distance between parents and the distance between parent and offspring are considered when they vote. Well-known combinatorial optimization problems, the traveling salesperson problem, and the graph bisection problem are used for the test bed of our method. Our adaptive strategy showed better results than not only pure and previous hybrid schemes but also existing distance-based mating schemes.

  1. Vehicle Net Habitable Volume (NHV) and Habitability Assessment

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this study is to assess habitability on the International Space Station (ISS) in order to better prepare for long-duration spaceflight missions of the...

  2. Not Only Single Mating in Stingless Bees

    Science.gov (United States)

    Paxton, Robert J.; Weißschuh, Nicole; Engels, Wolf; Hartfelder, Klaus; Quezada-Euan, J. Javier G.

    Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, me, was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony kin conflict in social Hymenoptera.

  3. Social wasps are a Saccharomyces mating nest.

    Science.gov (United States)

    Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

    2016-02-23

    The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

  4. Breaking Snake Camouflage: Humans Detect Snakes More Accurately than Other Animals under Less Discernible Visual Conditions.

    Science.gov (United States)

    Kawai, Nobuyuki; He, Hongshen

    2016-01-01

    Humans and non-human primates are extremely sensitive to snakes as exemplified by their ability to detect pictures of snakes more quickly than those of other animals. These findings are consistent with the Snake Detection Theory, which hypothesizes that as predators, snakes were a major source of evolutionary selection that favored expansion of the visual system of primates for rapid snake detection. Many snakes use camouflage to conceal themselves from both prey and their own predators, making it very challenging to detect them. If snakes have acted as a selective pressure on primate visual systems, they should be more easily detected than other animals under difficult visual conditions. Here we tested whether humans discerned images of snakes more accurately than those of non-threatening animals (e.g., birds, cats, or fish) under conditions of less perceptual information by presenting a series of degraded images with the Random Image Structure Evolution technique (interpolation of random noise). We find that participants recognize mosaic images of snakes, which were regarded as functionally equivalent to camouflage, more accurately than those of other animals under dissolved conditions. The present study supports the Snake Detection Theory by showing that humans have a visual system that accurately recognizes snakes under less discernible visual conditions.

  5. Are stripes beneficial? Dazzle camouflage influences perceived speed and hit rates.

    Directory of Open Access Journals (Sweden)

    Bettina von Helversen

    Full Text Available In the animal kingdom, camouflage refers to patterns that help potential prey avoid detection. Mostly camouflage is thought of as helping prey blend in with their background. In contrast, disruptive or dazzle patterns protect moving targets and have been suggested as an evolutionary force in shaping the dorsal patterns of animals. Dazzle patterns, such as stripes and zigzags, are thought to reduce the probability with which moving prey will be captured by impairing predators' perception of speed. We investigated how different patterns of stripes (longitudinal-i.e., parallel to movement direction-and vertical-i.e., perpendicular to movement direction affect the probability with which humans can hit moving objects and if differences in hitting probability are caused by a misperception of speed. A first experiment showed that longitudinally striped objects were hit more often than unicolored objects. However, vertically striped objects did not differ from unicolored objects. A second study examining the link between perceived speed and hitting probability showed that longitudinally and vertically striped objects were both perceived as moving faster and were hit more often than unicolored objects. In sum, our results provide evidence that striped patterns disrupt the perception of speed, which in turn influences how often objects are hit. However, the magnitude and the direction of the effects depend on additional factors such as speed and the task setup.

  6. Breaking Snake Camouflage: Humans Detect Snakes More Accurately than Other Animals under Less Discernible Visual Conditions.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kawai

    Full Text Available Humans and non-human primates are extremely sensitive to snakes as exemplified by their ability to detect pictures of snakes more quickly than those of other animals. These findings are consistent with the Snake Detection Theory, which hypothesizes that as predators, snakes were a major source of evolutionary selection that favored expansion of the visual system of primates for rapid snake detection. Many snakes use camouflage to conceal themselves from both prey and their own predators, making it very challenging to detect them. If snakes have acted as a selective pressure on primate visual systems, they should be more easily detected than other animals under difficult visual conditions. Here we tested whether humans discerned images of snakes more accurately than those of non-threatening animals (e.g., birds, cats, or fish under conditions of less perceptual information by presenting a series of degraded images with the Random Image Structure Evolution technique (interpolation of random noise. We find that participants recognize mosaic images of snakes, which were regarded as functionally equivalent to camouflage, more accurately than those of other animals under dissolved conditions. The present study supports the Snake Detection Theory by showing that humans have a visual system that accurately recognizes snakes under less discernible visual conditions.

  7. Development and application of diurnal thermal modeling for camouflage, concealment, and deception

    Science.gov (United States)

    Rodgers, Mark L. B.

    2000-07-01

    The art of camouflage is to make a military asset appear to be part of the natural environment: its background. In order to predict the likely performance of countermeasures in attaining this goal it is necessary to model the signatures of targets, backgrounds and the effect of countermeasures. A library of diurnal thermal models has been constructed covering a range of backgrounds from vegetated and non- vegetated surfaces to snow cover. These models, originally developed for Western Europe, have been validated successfully for theatres of operation from the arctic to the desert. This paper will show the basis for and development of physically based models for the diurnal thermal behavior both of these backgrounds and for major passive countermeasures: camouflage nets and continuous textile materials. The countermeasures set up significant challenges for the thermal modeler with their low but non-zero thermal inertial and the extent to which they influence local aerodynamic behavior. These challenges have been met and the necessary extensive validation has shown the ability of the models to predict successfully the behavior of in-service countermeasures.

  8. Are "Habitable" Exoplanets Really Habitable? -A perspective from atmospheric loss

    Science.gov (United States)

    Dong, C.; Huang, Z.; Jin, M.; Lingam, M.; Ma, Y. J.; Toth, G.; van der Holst, B.; Airapetian, V.; Cohen, O.; Gombosi, T. I.

    2017-12-01

    In the last two decades, the field of exoplanets has witnessed a tremendous creative surge. Research in exoplanets now encompasses a wide range of fields ranging from astrophysics to heliophysics and atmospheric science. One of the primary objectives of studying exoplanets is to determine the criteria for habitability, and whether certain exoplanets meet these requirements. The classical definition of the Habitable Zone (HZ) is the region around a star where liquid water can exist on the planetary surface given sufficient atmospheric pressure. However, this definition largely ignores the impact of the stellar wind and stellar magnetic activity on the erosion of an exoplanet's atmosphere. Amongst the many factors that determine habitability, understanding the mechanisms of atmospheric loss is of paramount importance. We will discuss the impact of exoplanetary space weather on climate and habitability, which offers fresh insights concerning the habitability of exoplanets, especially those orbiting M-dwarfs, such as Proxima b and the TRAPPIST-1 system. For each case, we will demonstrate the importance of the exoplanetary space weather on atmospheric ion loss and habitability.

  9. Disrupting Mating Behavior of Diaphorina citri (Liviidae).

    Science.gov (United States)

    Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

    2016-12-01

    Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  10. Cutaneous lasers and skin camouflage make-up: a useful alternative intervention for periorbital hairy congenital melanocytic naevus.

    Science.gov (United States)

    Townley, William A; Bragg, Thomas W H; Wright, Philip A; Cole, Richard P

    2013-12-01

    Periorbital congenital melanocytic naevi can be very disfiguring and difficult to treat effectively. Although surgical excision and reconstruction is the most widely accepted treatment strategy, we describe a case in which cutaneous lasers treatment followed by the application of cosmetic skin camouflage make-up provided an alternative solution delivering a good cosmetic improvement.

  11. Psychological and psychosocial functioning of children with burn scarring using cosmetic camouflage: a multi-centre prospective randomised controlled trial.

    Science.gov (United States)

    Maskell, Jessica; Newcombe, Peter; Martin, Graham; Kimble, Roy

    2014-02-01

    Burns leave patients with long-term physical scarring. Children with scarring are required to face challenges of reintegration into their community, including acceptance of an altered appearance and acceptance by others. This can be difficult given society's preoccupation with physical appearance. Limited research exists investigating validity of cosmetic camouflage as a psychosocial intervention for children with scarring. This study investigated whether using cosmetic camouflage (Microskin™) had a positive impact on health-related quality of life, self-concept and psychopathology for children and adolescents (8-17 years) with burn scarring. A prospective multi-centre randomised controlled trial was conducted across Australian and New Zealand paediatric hospitals. 63 participants (49 females, mean age 12.7 ± 2.1 years) were enrolled. Data points were baseline (Time 1) and at 8 weeks (Time 2) using reliable and valid psychometric measures. Findings indicate there were significant improvements in socialisation, school and appearance scales on the Paediatric Quality of Life Inventory and psychopathology scores particularly peer problems decreased. However self-concept remained stable from baseline throughout intervention use. Cosmetic camouflage appears to have a positive impact on quality of life particularly socialisation. Cosmetic camouflage is a valid tool to assist children with scarring to actively participate socially within their communities. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  12. Changeable camouflage: how well can flounder resemble the colour and spatial scale of substrates in their natural habitats?

    Science.gov (United States)

    Akkaynak, Derya; Siemann, Liese A; Barbosa, Alexandra; Mäthger, Lydia M

    2017-03-01

    Flounder change colour and pattern for camouflage. We used a spectrometer to measure reflectance spectra and a digital camera to capture body patterns of two flounder species camouflaged on four natural backgrounds of different spatial scale (sand, small gravel, large gravel and rocks). We quantified the degree of spectral match between flounder and background relative to the situation of perfect camouflage in which flounder and background were assumed to have identical spectral distribution. Computations were carried out for three biologically relevant observers: monochromatic squid, dichromatic crab and trichromatic guitarfish. Our computations present a new approach to analysing datasets with multiple spectra that have large variance. Furthermore, to investigate the spatial match between flounder and background, images of flounder patterns were analysed using a custom program originally developed to study cuttlefish camouflage. Our results show that all flounder and background spectra fall within the same colour gamut and that, in terms of different observer visual systems, flounder matched most substrates in luminance and colour contrast. Flounder matched the spatial scales of all substrates except for rocks. We discuss findings in terms of flounder biology; furthermore, we discuss our methodology in light of hyperspectral technologies that combine high-resolution spectral and spatial imaging.

  13. Managing away bad habits.

    Science.gov (United States)

    Waldroop, J; Butler, T

    2000-01-01

    We've all worked with highly competent people who are held back by a seemingly fatal personality flaw. One person takes on too much work; another sees the downside in every proposed change; a third pushes people out of the way. At best, people with these "bad habits" create their own glass ceilings, which limit their success and their contributions to the company. At worst, they destroy their own careers. Although the psychological flaws of such individuals run deep, their managers are not helpless. In this article, James Waldroop and Timothy Butler--both psychologists--examine the root causes of these flaws and suggest concrete tactics they have used to help people recognize and correct the following six behavior patterns: The hero, who always pushes himself--and subordinates--too hard to do too much for too long. The meritocrat, who believes that the best ideas can and will be determined objectively and ignores the politics inherent in most situations. The bulldozer, who runs roughshod over others in a quest for power. The pessimist, who always worries about what could go wrong. The rebel, who automatically fights against authority and convention. And the home run hitter, who tries to do too much too soon--he swings for the fences before he's learned to hit singles. Helping people break through their self-created glass ceilings is the ultimate win-win scenario: both the individual and the organization are rewarded. Using the tactics introduced in this article, managers can help their brilliantly flawed performers become spectacular achievers.

  14. Northern Fur Seal Food Habits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains food habits samples, usually scats, collected opportunistically on northern fur seal rookeries and haulouts in Alaska from 1987 to present....

  15. Healthy Habits Can Lengthen Life

    Science.gov (United States)

    ... 2018 Print this issue Health Capsule Healthy Habits Can Lengthen Life Send us your comments Physical activity is one of five healthy lifestyle factors that can lower your risk for several diseases and lengthen ...

  16. Make peak flow a habit

    Science.gov (United States)

    Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

  17. [Habitability and life support systems].

    Science.gov (United States)

    Nefedov, Iu G; Adamovich, B A

    1988-01-01

    This paper discusses various aspects of space vehicle habitability and life support systems. It describes variations in the chemical and microbial composition of an enclosed atmosphere during prolonged real and simulated flights. The paper gives a detailed description of life support systems and environmental investigations onboard the Mir station. It also outlines the development of space vehicle habitability and life support systems as related to future flights.

  18. Comparison of incisor inclination in patients with Class III malocclusion treated with orthognathic surgery or orthodontic camouflage.

    Science.gov (United States)

    Troy, Beth A; Shanker, Shiva; Fields, Henry W; Vig, Katherine; Johnston, William

    2009-02-01

    Reports comparing Class III patients treated by camouflage and those treated by orthognathic surgery are not numerous. The purpose of this study was to compare the dental and skeletal values of Class III patients treated with these methods against normative data and over the course of treatment. Thirty-three surgical and 39 camouflage Class III patients were selected from a graduate orthodontic clinic and regional private practices, and lateral cephalograms were digitized. Skeletal and dental values were obtained, and mean and efficacy evaluations referenced to ethnic norms were calculated. At pretreatment, the surgery patients had more severe skeletal discrepancies and more compensated incisors. During presurgical orthodontic treatment, most of the surgery group's mandibular incisors were significantly decompensated, although half of the maxillary incisors remained compensated. The surgical move improved 90% of these patients but to only 60% to 65% of the norm. The camouflage group was compensated at pretreatment, and they became more compensated in the end. After treatment, there were no differences between the incisor positions of the 2 groups. There was no statistical difference in incisor inclination and position between the Class III surgical and camouflage groups after treatment; there was a significant difference in the pretreatment and posttreatment incisor inclination and position compared with normative values for both the surgical and the camouflage groups; the maxillary and mandibular incisors were not adequately decompensated in the surgical group, but significant improvement in mandibular incisor position and axial inclination was achieved presurgically. The outcome of the surgical correction was limited by the inadequate presurgical orthodontic incisor decompensation, and orthodontic compensation of incisors occurred postsurgically to achieve an optimal occlusal result.

  19. Mating Disruption for the 21st Century: Matching Technology With Mechanism.

    Science.gov (United States)

    Miller, James R; Gut, Larry J

    2015-06-01

    inverse of catch is plotted against density of pheromone dispensers; and, a recurving plot when catch is plotted against density of pheromone dispensers x catch. Hybrid profiles are possible when some males within the population begin the activity period already incapacitated, while those not preexposed have the capacity to respond either to traps or pheromone dispensers. Competitive mechanisms include competitive attraction, induced allopatry, and induced arrestment. Noncompetitive mechanisms include desensitization and inhibition, induced allochrony, suppressed calling and mating, camouflage, and sensory imbalance. Examples of the various disruption types within the two major categories and suggested tactics for differentiating among them are offered as seven case studies of the disruption of important pest species using various formulations are analyzed in depth. We point out how economic optimizations may be achieved once the principal and contributory causes of disruption are proven. Hopefully, these insights will pave the way to a broader and more reliable usage of this environmentally friendly pest management tactic. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Parent-Offspring Conflict over Mating: The Case of Beauty

    Directory of Open Access Journals (Sweden)

    Menelaos Apostolou

    2008-04-01

    Full Text Available In pre-industrial societies parents exercise a strong influence over the mating decisions of their offspring. As modern pre-industrial societies approximate the way of life in ancestral human societies, human mating behavior should be seen as the outcome of a co-evolutionary process between parental and offspring's mating choice. Both parents and offspring have evolved mating preferences, which enable them to select those mates and in-laws who maximize their inclusive fitness. Following Trivers' (1974 theory of parent-offspring conflict, it is hypothesized that in-law and mating preferences substantially overlap, but also differ with respect to the beauty trait of a mating candidate. This hypothesis is tested on a sample of 292 parents. It is found that the two sets of preferences are strongly correlated, while beauty is preferred significantly more in a mating partner than in an in-law.

  1. Heterozygosity-based assortative mating in blue tits (Cyanistes caeruleus): implications for the evolution of mate choice

    Science.gov (United States)

    García-Navas, Vicente; Ortego, Joaquín; Sanz, Juan José

    2009-01-01

    The general hypothesis of mate choice based on non-additive genetic traits suggests that individuals would gain important benefits by choosing genetically dissimilar mates (compatible mate hypothesis) and/or more heterozygous mates (heterozygous mate hypothesis). In this study, we test these hypotheses in a socially monogamous bird, the blue tit (Cyanistes caeruleus). We found no evidence for a relatedness-based mating pattern, but heterozygosity was positively correlated between social mates, suggesting that blue tits may base their mating preferences on partner's heterozygosity. We found evidence that the observed heterozygosity-based assortative mating could be maintained by both direct and indirect benefits. Heterozygosity reflected individual quality in both sexes: egg production and quality increased with female heterozygosity while more heterozygous males showed higher feeding rates during the brood-rearing period. Further, estimated offspring heterozygosity correlated with both paternal and maternal heterozygosity, suggesting that mating with heterozygous individuals can increase offspring genetic quality. Finally, plumage crown coloration was associated with male heterozygosity, and this could explain unanimous mate preferences for highly heterozygous and more ornamented individuals. Overall, this study suggests that non-additive genetic traits may play an important role in the evolution of mating preferences and offers empirical support to the resolution of the lek paradox from the perspective of the heterozygous mate hypothesis. PMID:19474042

  2. Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

    Science.gov (United States)

    Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

    2012-02-01

    The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

  3. Inversion of the chromosomal region between two mating type loci switches the mating type in Hansenula polymorpha.

    Science.gov (United States)

    Maekawa, Hiromi; Kaneko, Yoshinobu

    2014-11-01

    Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci.

  4. Husband's Esteem Predicts his Mate Retention Tactics

    Directory of Open Access Journals (Sweden)

    Christopher J. Holden

    2014-07-01

    Full Text Available delity or prevent their defection from the relationship. These tactics include low-risk acts that render the current relationship more attractive by bestowing benefits on the woman, as well as cost-inflicting acts that render defection from the relationship risky or dangerous for her. Previous research has linked men's mate retention behavior with men's mate value (value as a current or potential partner using women's reports. The current research addresses limitations of that research using self-reports and cross-spousal reports from 107 married couples concerning their self-esteem and their esteem for their partner. The results indicate that the level of esteem that wives have for their husbands is positively associated with their perception of their husband's use of positive inducements and negatively associated with their husband's self-reported use of cost-inflicting mate retention behaviors (i.e., Direct Guarding, Intersexual Negative Inducements, and Intrasexual Negative Inducements. The level of self-esteem reported by men was negatively associated with their self-reported direct guarding behavior. Discussion explores the possibility that esteem—both self-esteem and esteem from one's partner—functions as an internal gauge of relative mate value.

  5. AA, mating of BST magnet halves

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The AA had 2 types of bending magnets: BLG (window-frame,long and narrow) and BST (H-type, short and wide). The BST had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see the mating of two BST halves.

  6. The evolution of postpairing male mate choice.

    Science.gov (United States)

    Lyu, Nan; Servedio, Maria R; Lloyd, Huw; Sun, Yue-Hua

    2017-06-01

    An increasing number of empirical studies in animals have demonstrated male mate choice. However, little is known about the evolution of postpairing male choice, specifically which occurs by differential allocation of male parental care in response to female signals. We use a population genetic model to examine whether such postpairing male mate choice can evolve when males face a trade-off between parental care and extra-pair copulations (EPCs). Specifically, we assume that males allocate more effort to providing parental care when mated to preferred (signaling) females, but they are then unable to allocate additional effort to seek EPCs. We find that both male preference and female signaling can evolve in this situation, under certain conditions. First, this evolution requires a relatively large difference in parental investment between males mated to preferred versus nonpreferred females. Second, whether male choice and female signaling alleles become fixed in a population versus cycle in their frequencies depends on the additional fecundity benefits from EPCs that are gained by choosy males. Third, less costly female signals enable both signaling and choice alleles to evolve under more relaxed conditions. Our results also provide a new insight into the evolution of sexual conflict over parental care. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  7. COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole, E-mail: rory@astro.washington.edu [Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195 (United States)

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  8. COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

    International Nuclear Information System (INIS)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole

    2015-01-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions

  9. The mating behaviour and reproduction performance in a multi-sire mating system for pigs

    DEFF Research Database (Denmark)

    Kongsted, Anne Grete; Hermansen, John Erik

    2008-01-01

    . The observations revealed numerous poor quality matings, a huge variation in the number of times sows are mated, and overworked boars. Only 35% of all copulations lasted 2 min or more and 63% of all copulations were disrupted, mainly by competitor boars. The higher social status of the boar, the more copulations...... did it disrupt (p performance was observed, indicating scope for improvements...

  10. Autostéréogramme d'une montagne gaussienne -utilisant une structure paradoxale périodique comme texture de camouflage-

    OpenAIRE

    Colonna , Jean-François

    2011-01-01

    Autostereogram -using a periodical paradoxal structure as a desguise texture- with an hidden gaussian mountain (Autostéréogramme d'une montagne gaussienne -utilisant une structure paradoxale périodique comme texture de camouflage-)

  11. Signal transduction during mating and meiosis in S. pombe

    DEFF Research Database (Denmark)

    Nielsen, O; Nielsen, Olaf

    1993-01-01

    When starved, the fission yeast Schizosaccharomyces pombe responds by producing mating factors or pheromones that signal to cells of the opposite sex to initiate mating. Like its distant relative Saccharomyces cerevisiae, cells of the two mating types of S. pombe each produce a distinct pheromone...

  12. Size and competitive mating success in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Smith, Carl; Pomiankowski, Andrew; Greig, Duncan

    2014-03-01

    In unicellular organisms like yeast, mating with the right partner is critical to future fitness because each individual can only mate once. Because cell size is important for viability, mating with a partner of the right size could be a significant advantage. To investigate this idea, we manipulated the size of unmated yeast cells and showed that their viability depended on environmental conditions; large cells do better on rich medium and small cells do better on poor medium. We also found that the fitness of offspring is determined by the size of their parents. Finally, we demonstrated that when a focal cell of one mating type was placed with a large and a small cell of the opposite mating type, it was more likely to mate with the cell that was closer to the optimum size for growth in a given environment. This pattern was not generated by differences in passive mating efficiency of large and small cells across environments but by competitive mating behavior, mate preference, or both. We conclude that the most likely mechanism underlying this interesting behavior is that yeast cells compete for mates by producing pheromone signals advertising their viability, and cells with the opportunity to choose prefer to mate with stronger signalers because such matings produce more viable offspring.

  13. Mate choice in the face of costly competition

    NARCIS (Netherlands)

    Fawcett, TW; Johnstone, RA

    2003-01-01

    Studies of mate choice commonly ignore variation in preferences and assume that all individuals should favor the highest-quality mate available. However, individuals may differ in their mate preferences according to their own age, experience, size, or genotype. In the present study, we highlight

  14. Body size and mating success in Drosophila willistoni are ...

    Indian Academy of Sciences (India)

    Mating activity and wing length were investigated in the F1 progeny of Drosophila willistoni females collected in the field to examine any possible relationship between body size and mating success. The flies were observed in a mating chamber under laboratory conditions. No significant differences in wing length were ...

  15. Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

    Science.gov (United States)

    Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

    2011-01-01

    Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

  16. Cultural Variation in Parental Influence on Mate Choice

    NARCIS (Netherlands)

    Buunk, Abraham P.; Park, Justin H.; Duncan, Lesley A.

    Contrary to assumptions underlying current psychological theories of human mating, throughout much of human history parents often controlled the mating behavior of their children. In the present research, the authors tested the hypothesis that the level of parental influence on mating is associated

  17. Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success

    International Nuclear Information System (INIS)

    Silva Neto, Alberto M. da; Dias, Vanessa S.; Joachim-Bravo, Iara S.

    2009-01-01

    The objective of this study was to evaluate the effect of male ageing on male pheromone release and mating success of Ceratitis capitata (Wiedemann). The effects of male ageing on mating were evaluated on fi ve and 21 d-old males by assessing their mating success (males chosen by a female for copulation) and the amount of males releasing the sex pheromone. The mating success was evaluated by using several ratios of young to older males by increasing the number of older males:young males from 1:1 to 5:1. The mating success of the 1:1 ratio was also evaluated in fi eld cages. The evaluation of the mating success (in the 1:1 ratio) showed a clear preference of the females for young males. Sex pheromone emission was much more common on young than older males. Even in cases were older males were more abundant (ratios 2:1 and 3:1), females still chose the young males. However, females could not distinguish young from older males in ratios of 4:1 or 5:1. Our data indicate that the ageing of C. capitata males has a considerable negative effect on their reproductive success, especially if they are found in a proportion any lower than 3:1. (author)

  18. Habit formation, work ethics, and technological progress

    OpenAIRE

    Faria, João Ricardo; León-Ledesma, Miguel A.

    2002-01-01

    Work ethics affects labor supply. This idea is modeled assuming that work is habit forming. This paper introduces working habits in a neoclassical growth model and compares its outcomes with a model without habit formation. In addition, it analyzes the impact of different forms of technical progress. The findings are that i) labor supply in the habit formation case is higher than in the neoclassical case; ii) unlike in the neoclassical case, labor supply in the presence of habit formation wil...

  19. Habitable worlds with no signs of life

    OpenAIRE

    Cockell, Charles S.

    2014-01-01

    ‘Most habitable worlds in the cosmos will have no remotely detectable signs of life’ is proposed as a biological hypothesis to be tested in the study of exoplanets. Habitable planets could be discovered elsewhere in the Universe, yet there are many hypothetical scenarios whereby the search for life on them could yield negative results. Scenarios for habitable worlds with no remotely detectable signatures of life include: planets that are habitable, but have no biosphere (Uninhabited Habitable...

  20. Tidal locking of habitable exoplanets

    Science.gov (United States)

    Barnes, Rory

    2017-12-01

    Potentially habitable planets can orbit close enough to their host star that the differential gravity across their diameters can produce an elongated shape. Frictional forces inside the planet prevent the bulges from aligning perfectly with the host star and result in torques that alter the planet's rotational angular momentum. Eventually the tidal torques fix the rotation rate at a specific frequency, a process called tidal locking. Tidally locked planets on circular orbits will rotate synchronously, but those on eccentric orbits will either librate or rotate super-synchronously. Although these features of tidal theory are well known, a systematic survey of the rotational evolution of potentially habitable exoplanets using classic equilibrium tide theories has not been undertaken. I calculate how habitable planets evolve under two commonly used models and find, for example, that one model predicts that the Earth's rotation rate would have synchronized after 4.5 Gyr if its initial rotation period was 3 days, it had no satellites, and it always maintained the modern Earth's tidal properties. Lower mass stellar hosts will induce stronger tidal effects on potentially habitable planets, and tidal locking is possible for most planets in the habitable zones of GKM dwarf stars. For fast-rotating planets, both models predict eccentricity growth and that circularization can only occur once the rotational frequency is similar to the orbital frequency. The orbits of potentially habitable planets of very late M dwarfs ([InlineEquation not available: see fulltext.]) are very likely to be circularized within 1 Gyr, and hence, those planets will be synchronous rotators. Proxima b is almost assuredly tidally locked, but its orbit may not have circularized yet, so the planet could be rotating super-synchronously today. The evolution of the isolated and potentially habitable Kepler planet candidates is computed and about half could be tidally locked. Finally, projected TESS planets

  1. Age-dependent male mating investment in Drosophila pseudoobscura.

    Directory of Open Access Journals (Sweden)

    Sumit Dhole

    Full Text Available Male mating investment can strongly influence fitness gained from a mating. Yet, male mating investment often changes with age. Life history theory predicts that mating investment should increase with age, and males should become less discriminatory about their mate as they age. Understanding age-dependent changes in male behavior and their effects on fitness is important for understanding how selection acts in age-structured populations. Although the independent effects of male or female age have been studied in many species, how these interact to influence male mating investment and fitness is less well understood. We mated Drosophila pseudoobscura males of five different age classes (4-, 8-, 11-, 15-, 19-day old to either young (4-day or old (11-day females, and measured copulation duration and early post-mating fecundity. Along with their independent effects, we found a strong interaction between the effects of male and female ages on male mating investment and fitness from individual matings. Male mating investment increased with male age, but this increase was more prominent in matings with young females. Male D. pseudoobscura made smaller investments when mating with old females. The level of such discrimination based on female age, however, also changed with male age. Intermediate aged males were most discriminatory, while the youngest and the oldest males did not discriminate between females of different ages. We also found that larger male mating investments resulted in higher fitness payoffs. Our results show that male and female ages interact to form a complex pattern of age-specific male mating investment and fitness.

  2. A review of scalp camouflaging agents and prostheses for individuals with hair loss.

    Science.gov (United States)

    Donovan, Jeff C H; Shapiro, Ron L; Shapiro, Paul; Zupan, Matt; Pierre-Louis, Margareth; Hordinsky, Maria K

    2012-08-15

    Hair loss is a common problem for both men and women and may impact negatively on self-esteem. A variety of medical and surgical treatment options are available depending on the type of alopecia. Many patients also seek the advice of their physicians about options to hide or reduce the appearance of hair loss with hair prostheses (wigs, hairpieces, and extensions) or hair camouflaging agents (hair fibers, powder cakes, lotions, sprays, hair crayons, and scalp tattooing). Herein, we review current methods to hide or reduce the appearance of hair loss and discuss their associated costs, advantages, and disadvantages. Knowledge of products available to cover scalp, eyebrow, and eyelash hair loss may not only better equip clinicians to respond to questions from concerned patients, but may provide additional options to help these patients best cope with their hair loss.

  3. Orthodontic camouflage of skeletal Class III malocclusion with miniplate: a case report.

    Science.gov (United States)

    Farret, Marcel Marchiori; Farret, Milton M Benitez; Farret, Alessandro Marchiori

    2016-01-01

    Skeletal Class III malocclusion is often referred for orthodontic treatment combined with orthognathic surgery. However, with the aid of miniplates, some moderate discrepancies become feasible to be treated without surgery. To report the case of a 24-year-old man with severe skeletal Angle Class III malocclusion with anterior crossbite and a consequent concave facial profile. The patient refused to undergo orthognathic surgery; therefore, orthodontic camouflage treatment with the aid of miniplates placed on the mandibular arch was proposed. After 18 months of treatment, a Class I molar and canine relationship was achieved, while anterior crossbite was corrected by retraction of mandibular teeth. The consequent decrease in lower lip fullness and increased exposure of maxillary incisors at smiling resulted in a remarkable improvement of patient's facial profile, in addition to an esthetically pleasing smile, respectively. One year later, follow-up revealed good stability of results.

  4. Orthodontic camouflage via total arch movement in a Class II with idiopathic condylar resorption

    Directory of Open Access Journals (Sweden)

    Ji-Sung Jang

    2014-01-01

    Full Text Available Idiopathic condylar resorption (ICR, also known as idiopathic condylysis or condylar atrophy, is multifactorial pathology leading to severe mandibular retrognathism. The etiology has been shown to be multifactorial, such as avascular necrosis, traumatic injuries, hormone and autoimmune disease and it is largely difficult to distinguish the exact cause in each individual. In spite of the remarkable morphological alteration, surgical intervention is not readily recruited due to the possibility of recurrence of resorption. In order to restore balanced facial profile and occlusion. In this report, we present a camouflage treatment for skeletal Class II with ICR and facial asymmetry involving total arch movement, for the improvement facial profile and reconstruction of occlusion.

  5. Camouflage of Severe Skeletal Class II Gummy Smile Patient Treated Nonsurgically with Mini Implants

    Directory of Open Access Journals (Sweden)

    Irfan Qamruddin

    2014-01-01

    Full Text Available Skeletal class II has always been a challenge in orthodontics and often needs assistance of surgical orthodontics in nongrowing patients when it presents with severe discrepancy. Difficulty increases more when vertical dysplasia is also associated with sagittal discrepancy. The advent of mini implants in orthodontics has broadened the spectrum of camouflage treatment. This case report presents a 16-year-old nongrowing girl with severe class II because of retrognathic mandible, and anterior dentoalveolar protrusion sagittally and vertically resulted in severe overjet of 13 mm and excessive display of incisors and gums. Both maxillary central incisors were trimmed by general practitioner few years back to reduce visibility. Treatment involved use of micro implant for retraction and intrusion of anterior maxillary dentoalveolar segment while lower incisors were proclined to obtain normal overjet, and overbite and pleasing soft tissue profile. Smile esthetics was further improved with composite restoration of incisal edges of both central incisors.

  6. The Camouflage of the Sacred in the Short Fiction of Hemingway

    Directory of Open Access Journals (Sweden)

    Zaid Ali

    2014-01-01

    Full Text Available This essay examines the short fiction of Ernest Hemingway in the light of Mircea Eliade’s notion of the camouflage of the sacred and the larval survival of original spiritual meaning. A subterranean love pulsates beneath the terse dialogue of Hemingway’s characters whose inner life we glimpse only obliquely. In the short play (“Today Is Friday” and four short stories (“The Killers,” “A Clean Well-Lighted Place,” “Old Man at the Bridge,” and “The Light of the World,” discussed here, light imagery, biblical allusions, and the figure of Christ, reveal a hidden imaginary universe. This sacral dimension has been largely overlooked by critics who dwell on the ostensible spiritual absence that characterizes Hemingway’s fiction.

  7. Orthodontic camouflage of skeletal Class III malocclusion with miniplate: a case report

    Directory of Open Access Journals (Sweden)

    Marcel Marchiori Farret

    Full Text Available ABSTRACT Introduction: Skeletal Class III malocclusion is often referred for orthodontic treatment combined with orthognathic surgery. However, with the aid of miniplates, some moderate discrepancies become feasible to be treated without surgery. Objective: To report the case of a 24-year-old man with severe skeletal Angle Class III malocclusion with anterior crossbite and a consequent concave facial profile. Methods: The patient refused to undergo orthognathic surgery; therefore, orthodontic camouflage treatment with the aid of miniplates placed on the mandibular arch was proposed. Results: After 18 months of treatment, a Class I molar and canine relationship was achieved, while anterior crossbite was corrected by retraction of mandibular teeth. The consequent decrease in lower lip fullness and increased exposure of maxillary incisors at smiling resulted in a remarkable improvement of patient's facial profile, in addition to an esthetically pleasing smile, respectively. One year later, follow-up revealed good stability of results.

  8. Zaštitno-maskirni uređaj/Protective camouflage cover

    Directory of Open Access Journals (Sweden)

    Alexander Ivanovich Golodyaev

    2014-10-01

    ' boepripasov, a takže analiz metodov bor'by so sredstvami napadenija. Opisan sposob bor'by s 'umnymi' boepripasami i rabota za- ščitno-maskirovočnogo sredstva. Privedeno opisanie patenta. / Uniformity of protective camouflage installations significantly increases survivability of tanks on the move. This installation prevents an enemy from distinguishing a tank from a car or an empty trailer. A camouflage cover made of multilayer water-resistant material makes anti-tank shaped charge projectiles pre-detonate. Since most projectiles are designed for attacking ERA, the first detonation hits the camouflage cover instead of the armour. When the second detonation hits the ERA, its explosion neutralizes the shaped charge jet. This structure is considerably cheaper and much more effective than rubber protection models. The article analyses anti-tank combat means, 'smart' missile guidance methods and methods of fighting means of attack. It also gives methods of fighting 'smart' projectiles and the applications of this protective camouflage structure.

  9. The lantern shark's light switch: turning shallow water crypsis into midwater camouflage

    Science.gov (United States)

    Claes, Julien M.; Mallefet, Jérôme

    2010-01-01

    Bioluminescence is a common feature in the permanent darkness of the deep-sea. In fishes, light is emitted by organs containing either photogenic cells (intrinsic photophores), which are under direct nervous control, or symbiotic luminous bacteria (symbiotic photophores), whose light is controlled by secondary means such as mechanical occlusion or physiological suppression. The intrinsic photophores of the lantern shark Etmopterus spinax were recently shown as an exception to this rule since they appear to be under hormonal control. Here, we show that hormones operate what amounts to a unique light switch, by acting on a chromatophore iris, which regulates light emission by pigment translocation. This result strongly suggests that this shark's luminescence control originates from the mechanism for physiological colour change found in shallow water sharks that also involves hormonally controlled chromatophores: the lantern shark would have turned the initial shallow water crypsis mechanism into a midwater luminous camouflage, more efficient in the deep-sea environment. PMID:20410033

  10. Attracting predators without falling prey: chemical camouflage protects honeydew-producing treehoppers from ant predation.

    Science.gov (United States)

    Silveira, Henrique C P; Oliveira, Paulo S; Trigo, José R

    2010-02-01

    Predaceous ants are dominant organisms on foliage and represent a constant threat to herbivorous insects. The honeydew of sap-feeding hemipterans has been suggested to appease aggressive ants, which then begin tending activities. Here, we manipulated the cuticular chemical profiles of freeze-dried insect prey to show that chemical background matching with the host plant protects Guayaquila xiphias treehoppers against predaceous Camponotus crassus ants, regardless of honeydew supply. Ant predation is increased when treehoppers are transferred to a nonhost plant with which they have low chemical similarity. Palatable moth larvae manipulated to match the chemical background of Guayaquila's host plant attracted lower numbers of predatory ants than unchanged controls. Although aggressive tending ants can protect honeydew-producing hemipterans from natural enemies, they may prey on the trophobionts under shortage of alternative food resources. Thus chemical camouflage in G. xiphias allows the trophobiont to attract predaceous bodyguards at reduced risk of falling prey itself.

  11. Sunscreen for fish: co-option of UV light protection for camouflage.

    Directory of Open Access Journals (Sweden)

    Kaspar P Mueller

    Full Text Available Many animals change their body pigmentation according to illumination of their environment. In aquatic vertebrates, this reaction is mediated through aggregation or dispersion of melanin-filled vesicles (melanosomes in dermal pigment cells (melanophores. The adaptive value of this behavior is usually seen in camouflage by allowing the animal to visually blend into the background. When exposed to visible light from below, however, dark-adapted zebrafish embryos at the age of 2 days post fertilization (dpf surprisingly display dispersal instead of aggregation of melanosomes, i.e. their body coloration becomes dark on a bright background. Melanosomes of older embryos and early larvae (3-5 dpf on the other hand aggregate as expected under these conditions. Here we provide an explanation to this puzzling finding: Melanosome dispersion in larvae 3 dpf and older is efficiently triggered by ultraviolet (UV light, irrespective of the visual background, suggesting that the extent of pigmentation is a trade-off between threats from predation and UV irradiation. The UV light-induced dispersion of melanosomes thereby is dependent on input from retinal short wavelength-sensitive (SWS cone photoreceptors. In young embryos still lacking a functional retina, protection from UV light predominates, and light triggers a dispersal of melanosomes via photoreceptors intrinsic to the melanophores, regardless of the actual UV content. In older embryos and early larvae with functional retinal photoreceptors in contrast, this light-induced dispersion is counteracted by a delayed aggregation in the absence of UV light. These data suggest that the primary function of melanosome dispersal has evolved as a protective adaption to prevent UV damage, which was only later co-opted for camouflage.

  12. Sunscreen for Fish: Co-Option of UV Light Protection for Camouflage

    Science.gov (United States)

    Mueller, Kaspar P.; Neuhauss, Stephan C. F.

    2014-01-01

    Many animals change their body pigmentation according to illumination of their environment. In aquatic vertebrates, this reaction is mediated through aggregation or dispersion of melanin-filled vesicles (melanosomes) in dermal pigment cells (melanophores). The adaptive value of this behavior is usually seen in camouflage by allowing the animal to visually blend into the background. When exposed to visible light from below, however, dark-adapted zebrafish embryos at the age of 2 days post fertilization (dpf) surprisingly display dispersal instead of aggregation of melanosomes, i.e. their body coloration becomes dark on a bright background. Melanosomes of older embryos and early larvae (3–5 dpf) on the other hand aggregate as expected under these conditions. Here we provide an explanation to this puzzling finding: Melanosome dispersion in larvae 3 dpf and older is efficiently triggered by ultraviolet (UV) light, irrespective of the visual background, suggesting that the extent of pigmentation is a trade-off between threats from predation and UV irradiation. The UV light-induced dispersion of melanosomes thereby is dependent on input from retinal short wavelength-sensitive (SWS) cone photoreceptors. In young embryos still lacking a functional retina, protection from UV light predominates, and light triggers a dispersal of melanosomes via photoreceptors intrinsic to the melanophores, regardless of the actual UV content. In older embryos and early larvae with functional retinal photoreceptors in contrast, this light-induced dispersion is counteracted by a delayed aggregation in the absence of UV light. These data suggest that the primary function of melanosome dispersal has evolved as a protective adaption to prevent UV damage, which was only later co-opted for camouflage. PMID:24489905

  13. A global analysis of bird plumage patterns reveals no association between habitat and camouflage

    Directory of Open Access Journals (Sweden)

    Marius Somveille

    2016-11-01

    Full Text Available Evidence suggests that animal patterns (motifs function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types—mottled (irregular, scales, bars and spots (regular—and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species’ geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world’s birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world’s eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.

  14. Serum albumin 'camouflage' of plant virus based nanoparticles prevents their antibody recognition and enhances pharmacokinetics.

    Science.gov (United States)

    Pitek, Andrzej S; Jameson, Slater A; Veliz, Frank A; Shukla, Sourabh; Steinmetz, Nicole F

    2016-05-01

    Plant virus-based nanoparticles (VNPs) are a novel class of nanocarriers with unique potential for biomedical applications. VNPs have many advantageous properties such as ease of manufacture and high degree of quality control. Their biocompatibility and biodegradability make them an attractive alternative to synthetic nanoparticles (NPs). Nevertheless, as with synthetic NPs, to be successful in drug delivery or imaging, the carriers need to overcome several biological barriers including innate immune recognition. Plasma opsonization can tag (V)NPs for clearance by the mononuclear phagocyte system (MPS), resulting in shortened circulation half lives and non-specific sequestration in non-targeted organs. PEG coatings have been traditionally used to 'shield' nanocarriers from immune surveillance. However, due to broad use of PEG in cosmetics and other industries, the prevalence of anti-PEG antibodies has been reported, which may limit the utility of PEGylation in nanomedicine. Alternative strategies are needed to tailor the in vivo properties of (plant virus-based) nanocarriers. We demonstrate the use of serum albumin (SA) as a viable alternative. SA conjugation to tobacco mosaic virus (TMV)-based nanocarriers results in a 'camouflage' effect more effective than PEG coatings. SA-'camouflaged' TMV particles exhibit decreased antibody recognition, as well as enhanced pharmacokinetics in a Balb/C mouse model. Therefore, SA-coatings may provide an alternative and improved coating technique to yield (plant virus-based) NPs with improved in vivo properties enhancing drug delivery and molecular imaging. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Intraspecific Colour Variation among Lizards in Distinct Island Environments Enhances Local Camouflage

    Science.gov (United States)

    Marshall, Kate L. A.; Philpot, Kate E.; Damas-Moreira, Isabel; Stevens, Martin

    2015-01-01

    Within-species colour variation is widespread among animals. Understanding how this arises can elucidate evolutionary mechanisms, such as those underlying reproductive isolation and speciation. Here, we investigated whether five island populations of Aegean wall lizards (Podarcis erhardii) have more effective camouflage against their own (local) island substrates than against other (non-local) island substrates to avian predators, and whether this was linked to island differences in substrate appearance. We also investigated whether degree of local substrate matching varied among island populations and between sexes. In most populations, both sexes were better matched against local backgrounds than against non-local backgrounds, particularly in terms of luminance (perceived lightness), which usually occurred when local and non-local backgrounds were different in appearance. This was found even between island populations that historically had a land connection and in populations that have been isolated relatively recently, suggesting that isolation in these distinct island environments has been sufficient to cause enhanced local background matching, sometimes on a rapid evolutionary time-scale. However, heightened local matching was poorer in populations inhabiting more variable and unstable environments with a prolonged history of volcanic activity. Overall, these results show that lizard coloration is tuned to provide camouflage in local environments, either due to genetic adaptation or changes during development. Yet, the occurrence and extent of selection for local matching may depend on specific conditions associated with local ecology and biogeographic history. These results emphasize how anti-predator adaptations to different environments can drive divergence within a species, which may contribute to reproductive isolation among populations and lead to ecological speciation. PMID:26372454

  16. A global analysis of bird plumage patterns reveals no association between habitat and camouflage.

    Science.gov (United States)

    Somveille, Marius; Marshall, Kate L A; Gluckman, Thanh-Lan

    2016-01-01

    Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types-mottled (irregular), scales, bars and spots (regular)-and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species' geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world's birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world's eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.

  17. Intraspecific Colour Variation among Lizards in Distinct Island Environments Enhances Local Camouflage.

    Directory of Open Access Journals (Sweden)

    Kate L A Marshall

    Full Text Available Within-species colour variation is widespread among animals. Understanding how this arises can elucidate evolutionary mechanisms, such as those underlying reproductive isolation and speciation. Here, we investigated whether five island populations of Aegean wall lizards (Podarcis erhardii have more effective camouflage against their own (local island substrates than against other (non-local island substrates to avian predators, and whether this was linked to island differences in substrate appearance. We also investigated whether degree of local substrate matching varied among island populations and between sexes. In most populations, both sexes were better matched against local backgrounds than against non-local backgrounds, particularly in terms of luminance (perceived lightness, which usually occurred when local and non-local backgrounds were different in appearance. This was found even between island populations that historically had a land connection and in populations that have been isolated relatively recently, suggesting that isolation in these distinct island environments has been sufficient to cause enhanced local background matching, sometimes on a rapid evolutionary time-scale. However, heightened local matching was poorer in populations inhabiting more variable and unstable environments with a prolonged history of volcanic activity. Overall, these results show that lizard coloration is tuned to provide camouflage in local environments, either due to genetic adaptation or changes during development. Yet, the occurrence and extent of selection for local matching may depend on specific conditions associated with local ecology and biogeographic history. These results emphasize how anti-predator adaptations to different environments can drive divergence within a species, which may contribute to reproductive isolation among populations and lead to ecological speciation.

  18. Intraspecific Colour Variation among Lizards in Distinct Island Environments Enhances Local Camouflage.

    Science.gov (United States)

    Marshall, Kate L A; Philpot, Kate E; Damas-Moreira, Isabel; Stevens, Martin

    2015-01-01

    Within-species colour variation is widespread among animals. Understanding how this arises can elucidate evolutionary mechanisms, such as those underlying reproductive isolation and speciation. Here, we investigated whether five island populations of Aegean wall lizards (Podarcis erhardii) have more effective camouflage against their own (local) island substrates than against other (non-local) island substrates to avian predators, and whether this was linked to island differences in substrate appearance. We also investigated whether degree of local substrate matching varied among island populations and between sexes. In most populations, both sexes were better matched against local backgrounds than against non-local backgrounds, particularly in terms of luminance (perceived lightness), which usually occurred when local and non-local backgrounds were different in appearance. This was found even between island populations that historically had a land connection and in populations that have been isolated relatively recently, suggesting that isolation in these distinct island environments has been sufficient to cause enhanced local background matching, sometimes on a rapid evolutionary time-scale. However, heightened local matching was poorer in populations inhabiting more variable and unstable environments with a prolonged history of volcanic activity. Overall, these results show that lizard coloration is tuned to provide camouflage in local environments, either due to genetic adaptation or changes during development. Yet, the occurrence and extent of selection for local matching may depend on specific conditions associated with local ecology and biogeographic history. These results emphasize how anti-predator adaptations to different environments can drive divergence within a species, which may contribute to reproductive isolation among populations and lead to ecological speciation.

  19. Cosmetic effects of skin-crease camouflage incision versus longitudinal incision following carotid endarterectomy.

    Science.gov (United States)

    Kazimierczak, Arkadiusz; Rybicka, Anita; Rynio, Pawel; Gutowski, Piotr; Wiernicki, Ireneusz

    2018-03-01

    Despite the increasing use of carotid angioplasty and stenting (CAS), carotid endarterectomy (CEA) nonetheless remains a more medically beneficial method of treatment for carotid artery stenosis. Therefore, one possibility for progress within this procedure may be to use minimally invasive carotid surgery, especially when the scar is in plain sight: the use of the natural wrinkles (skin crease) as a camouflage of the skin incision provides significant cosmetic improvements. To compare the cosmetic effects of classic and trans-wrinkle CEA. To assess the distance between the carotid artery bifurcation (CAB) and the skin-crease incision whilst attempting CEA. It was a randomized prospective study with two groups: patients undergoing classic surgery (control group; n = 100) and skin-crease trans-wrinkle camouflaged CEA (study group; n = 100). Follow-up was at 2 months and 1 year. The medical results of the treatment were similar in both groups. The cumulative count of strokes and myocardial infarctions was 0.5% within 30 days, and after one year 3.5% (and 5.5% including cases of death). The superiority of the transverse crease being hidden compared to the conventional longitudinal technique was proven in the Patient and Observer Scar Assessment Scale (POSAS) score, respectively 11.4 ±1.0 vs. 14.1 ±3.4 (p = 0.0001) after 2 months and 13.5 ±2.8 vs. 14.1 ±3.4 (p = 0.039) after a year. Trans-wrinkle incision gives better cosmetic results, can be safely performed in most cases, and offers a comfortable approach during CEA.

  20. You can't always get what you want: size assortative mating by mutual mate choice as a resolution of sexual conflict

    Directory of Open Access Journals (Sweden)

    Thünken Timo

    2009-06-01

    Full Text Available Abstract Background Assortative mating patterns for mate quality traits like body size are often observed in nature. However, the underlying mechanisms that cause assortative mating patterns are less well known. Sexual selection is one important explanation for assortment, suggesting that i one (usually the female or both sexes could show preferences for mates of similar size or ii mutual mate choice could resolve sexual conflict over quality traits into assortment. We tested these hypotheses experimentally in the socially monogamous cichlid fish Pelvicachromis taeniatus, in which mate choice is mutual. Results In mate choice experiments, both sexes preferred large mates irrespective of own body size suggesting mating preferences are not size-assortative. Especially males were highly selective for large females, probably because female body size signals direct fitness benefits. However, when potential mates were able to interact and assess each other mutually they showed size-assortative mating patterns, i.e. the likelihood to mate was higher in pairs with low size differences between mates. Conclusion Due to variation in body size, general preferences for large mating partners result in a sexual conflict: small, lower quality individuals who prefer themselves large partners are unacceptable for larger individuals. Relative size mismatches between mates translate into a lower likelihood to mate, suggesting that the threshold to accept mates depends on own body size. These results suggest that the underlying mechanism of assortment in P. taeniatus is mutual mate choice resolving the sexual conflict over mates, rather than preference for mates of similar size.

  1. Negative-assortative mating for color in wolves.

    Science.gov (United States)

    Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

    2016-04-01

    There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  2. Variation in male mate choice in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Dominic A Edward

    Full Text Available Male mate choice has been reported in the fruit fly, Drosophila melanogaster, even though males of this species were previously thought to maximise their fitness by mating with all available females. To understand the evolution of male mate choice it is important to understand variation in male mating preferences. Two studies, using different stock populations and different methods, have reported contrasting patterns of variation in male mate choice in D. melanogaster. Two possible explanations are that there are evolved differences in each stock population or that the methods used to measure choice could have biased the results. We investigated these hypotheses here by repeating the methods used in one study in which variable male mate choice was found, using the stock population from the other study in which choice was not variable. The results showed a significant resource-independent male preference for less fecund, smaller females, which contrasts with previous observations of male mate choice. This indicates that different selection pressures between populations have resulted in evolved differences in the expression of male mate choice. It also reveals phenotypic plasticity in male mate choice in response to cues encountered in each choice environment. The results highlight the importance of variation in male mate choice, and of identifying mechanisms in order to understand the evolution of mate choice under varying ecological conditions.

  3. Adolescents and Young Adults Mates Selection

    Directory of Open Access Journals (Sweden)

    María Martina Casullo

    2016-02-01

    Full Text Available The study sought to identify the relation between gender and age on mate pre- ferences using an intentional sample drawn in Buenos Aires city and its suburban area. A questionnaire adapted from a previous study developed by D.Buss (1990 requested subjects to rank each of 19 characteristics on its desirability in a mate. Subjects for this study were 900 adolescents and young adults aging 13 to 30 years old. Means and standard deviations were calculated as well as Spearman ́s Rho coefficients. High correlations between gender, age, and ordering were found. Mutual attraction and love, kindness and understanding and trust are cho- sen as the most important criteria. Phisically attractive is important for younger males. Similar political and religious background as well as chastity are conside- red among the less important criteria. 

  4. Socioeconomic Development and Shifts in Mate Preferences

    Directory of Open Access Journals (Sweden)

    Emily A. Stone

    2008-07-01

    Full Text Available Mate preferences shift according to contexts such as temporal duration of mateship sought and ecological prevalence of parasites. One important cross-cultural context that has not been explored is a country's socioeconomic development. Because individuals in less developed countries are generally less healthy and possess fewer resources than those in more developed countries, displays of health and resources in a prospective long-term partner were hypothesized to be valued more in populations in which they are rare than in populations in which they are more common. We also predicted negative correlations between development and preferences for similar religious background and a desire for children. We found strong support for the health hypothesis and modest support for the resource acquisition potential hypothesis. We also found an unpredicted positive correlation between development and importance ratings for love. Discussion addresses limitations of the current research and highlights directions for future cross-cultural research on mating psychology.

  5. Sport participation influences perceptions of mate characteristics.

    Science.gov (United States)

    Schulte-Hostedde, Albrecht I; Eys, Mark A; Emond, Michael; Buzdon, Michael

    2012-02-22

    Sport provides a context in which mate choice can be facilitated by the display of athletic prowess. Previous work has shown that, for females, team sport athletes are more desirable as mates than individual sport athletes and non-participants. In the present study, the perceptions of males and females were examined regarding potential mates based on sport participation. It was predicted that team sport athletes would be more positively perceived than individual sport athletes and non-participants by both males and females. A questionnaire, a photograph, and manipulated descriptions were used to gauge perceptual differences with respect to team sport athletes, individual sport athletes, and extra-curricular club participants for 125 females and 119 males from a Canadian university. Both team and individual sport athletes were perceived as being less lazy, more competitive, and healthier than non-participants by both males and females. Interestingly, females perceived male athletes as more promiscuous than non-athletes, which upholds predictions based on previous research indicating (a) athletes have more sexual partners than non-athletes, and (b) females find athletes more desirable as partners than non-participants. Surprisingly, only males perceived female team sport athletes as more dependable than non-participants, and both team and individual sport athletes as more ambitious. This raises questions regarding the initial hypothesis that male team athletes would be perceived positively by females because of qualities such as the ability to cooperate, likeability, and the acceptance of responsibilities necessary for group functioning. Future studies should examine similar questions with a larger sample size that encompasses multiple contexts, taking into account the role of the social profile of sport in relation to mate choice and perception.

  6. Estrogens can disrupt amphibian mating behavior.

    Directory of Open Access Journals (Sweden)

    Frauke Hoffmann

    Full Text Available The main component of classical contraceptives, 17α-ethinylestradiol (EE2, has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L, alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline.

  7. Bug City: Crickets, Grasshoppers & Friends [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon, including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic…

  8. Bug City: Aquatic Insects [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  9. Bug City: Beetles [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  10. Bug City: Bees [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  11. Bug City: Flies & Mosquitoes [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon, including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic…

  12. Bug City: Ladybugs & Fireflies [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon, including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic…

  13. Bug City: Spiders and Scorpions [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  14. Bug City: Butterflies and Moths [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  15. Bug City: House and Backyard Insects [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…

  16. Bug City: Ants [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic…

  17. Mating type genes in the genus Neofusicoccum: Mating strategies and usefulness in species delimitation.

    Science.gov (United States)

    Lopes, Anabela; Phillips, Alan J L; Alves, Artur

    2017-04-01

    The genus Neofusicoccum includes species with wide geographical and plant host distribution, some of them of economic importance. The genus currently comprises 27 species that are difficult to identify based on morphological features alone. Thus, species differentiation is based on phylogenetic species recognition using multigene genealogies. In this study, we characterised the mating type genes of Neofusicoccum species. Specific primers were designed to amplify and sequence MAT genes in several species and a PCR-based mating type diagnostic assay was developed. Homothallism was the predominant mating strategy among the species tested. Furthermore, the potential of mating type gene sequences for species delimitation was evaluated. Phylogenetic analyses were performed on both MAT genes and compared with multigene genealogies using sequences of the ribosomal internal transcribed spacer region, translation elongation factor 1-alpha and beta-tubulin. Phylogenies based on mating type genes could discriminate between the species analysed and are in concordance with the results obtained with the more conventional multilocus phylogenetic analysis approach. Thus, MAT genes represent a powerful tool to delimit cryptic species in the genus Neofusicoccum. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  18. Mate choice and human stature: homogamy as a unified framework for understanding mating preferences.

    Science.gov (United States)

    Courtiol, Alexandre; Raymond, Michel; Godelle, Bernard; Ferdy, Jean-Baptiste

    2010-08-01

    Assortative mating for human height has long attracted interest in evolutionary biology, and the phenomenon has been demonstrated in numerous human populations. It is often argued that mating preferences generate this pattern, but other processes can also induce trait correlations between mates. Here, we present a methodology tailored to quantify continuous preferences based on choice experiments between pairs of stimuli. In particular, it is possible to explore determinants of interindividual variations in preferences, such as the height of the chooser. We collected data from a sample of 200 individuals from France. Measurements obtained show that the perception of attractiveness depends on both the height of the stimuli and the stature of the individual who judged them. Therefore, this study demonstrates that homogamy is present at the level of preferences for both sexes. We also show that measurements of the function describing this homogamy are concordant with several distinct mating rules proposed in the literature. In addition, the quantitative approach introduced here fulfills metrics that can be used to compare groups of individuals. In particular, our results reveal an important disagreement between sexes regarding height preferences in the context of mutual mate choice. Finally, both women and men prefer individuals who are significantly taller than average. All major findings are confirmed by a reanalysis of previously published data.

  19. 7 Habits of Developmental Coaches

    Science.gov (United States)

    Darden, Gibson; Shimon, Jane

    2004-01-01

    In this article, the authors describe how coaches can apply principles of athlete growth and development to the learning and performance of motor skills. They present 7 habits that lead to well-rounded athletes who experience increased enjoyment, self-motivation, skill improvement, and ultimately more success on the playing field. (Contains 1…

  20. Are camouflaged seeds less attacked by wild birds? Sementes camufladas são menos atacadas por aves silvestres?

    Directory of Open Access Journals (Sweden)

    Alexandre de Almeida

    2010-04-01

    Full Text Available Wheat, corn and rice crops in Brazil use seeds treated with systemic insecticide/nematicide carbofuran, mixed to rhodamine B red dye. Carbofuran is toxic and rhodamine B is attractive to wild birds that eat up these seeds, resulting in notable mortality during planting. A field experiment was performed in southeast Brazil to evaluate if camouflaged seeds would be less consumed by wild birds in comparison to commercial seeds with red-colored rhodamine B and aposematic blue seeds. Camouflaged seeds were less removed than seeds with rhodamine B and natural colors. The camouflaging was more effective in the presence of irregularities and litter. There was no removal of blue-colored seeds. As legislation requires treated seeds to receive a different color to avoid accidents with humans, camouflaging may be used as replacement of rhodamine B to reduce mortality rates of wild birds.Plantações de trigo milho e arroz no Brasil utilizam sementes tratadas com o inseticida e nematicida sistêmico carbofuran, associado ao corante vermelho rodamina B. O carbofuran é tóxico e a rodamina B é atrativa às aves silvestres, as quais consomem estas sementes, resultando em notável mortalidade durante o plantio. Um experimento realizado em campo agrícola no sudeste do Brasil mostrou que sementes camufladas foram menos removidas por aves silvestres do que sementes com rodamina B. A camuflagem foi potencializada em presença de irregularidades e serrapilheira no solo. Não houve remoção de sementes de cor azul, mas a formulação granular de cor azul tem causado mortalidade de aves nos USA e Canadá. Como sementes tratadas com agrotóxicos devem, de acordo com a legislação, receber coloração diferenciada para evitar acidentes com humanos, a camuflagem pode ser utilizada, substituindo a rodamina B.

  1. Adaptive camouflage: what can be learned from the wetting behaviour of the tropical flat bugs Dysodius lunatus and Dysodius magnus

    Directory of Open Access Journals (Sweden)

    Florian Hischen

    2017-08-01

    Full Text Available The neotropical flat bug species Dysodius lunatus and Dysodius magnus show a fascinating camouflage principle, as their appearance renders the animal hardly visible on the bark of trees. However, when getting wet due to rain, bark changes its colour and gets darker. In order to keep the camouflage effect, it seems that some Dysodius species benefit from their ability to hold a water film on their cuticle and therefore change their optical properties when also wetted by water. This camouflage behaviour requires the insect to have a hydrophilic surface and passive surface structures which facilitate the liquid spreading. Here we show morphological and chemical characterisations of the surface, especially the cuticular waxes of D. magnus. Scanning electron microscopy revealed that the animal is covered with pillar-like microstructures which, in combination with a surprising chemical hydrophilicity of the cuticle waxes, render the bug almost superhydrophilic: water spreads immediately across the surface. We could theoretically model this behaviour assuming the effect of hemi-wicking (a state in which a droplet sits on a rough surface, partwise imbibing the structure around.  Additionally the principle was abstracted and a laser-patterned polymer surface, mimicking the structure and contact angle of Dysodius wax, shows exactly the behaviour of the natural role model – immediate spreading of water and the formation of a thin continuous water film changing optical properties of the surface.

  2. Adaptive camouflage: what can be learned from the wetting behaviour of the tropical flat bugs Dysodius lunatus and Dysodiusmagnus.

    Science.gov (United States)

    Hischen, Florian; Reiswich, Vladislav; Kupsch, Desirée; De Mecquenem, Ninon; Riedel, Michael; Himmelsbach, Markus; Weth, Agnes; Heiss, Ernst; Armbruster, Oskar; Heitz, Johannes; Baumgartner, Werner

    2017-08-15

    The neotropical flat bug species Dysodius lunatus and Dysodius magnus show a fascinating camouflage principle, as their appearance renders the animal hardly visible on the bark of trees. However, when getting wet due to rain, bark changes its colour and gets darker. In order to keep the camouflage effect, it seems that some Dysodius species benefit from their ability to hold a water film on their cuticle and therefore change their optical properties when also wetted by water. This camouflage behaviour requires the insect to have a hydrophilic surface and passive surface structures which facilitate the liquid spreading. Here we show morphological and chemical characterisations of the surface, especially the cuticular waxes of D. magnus Scanning electron microscopy revealed that the animal is covered with pillar-like microstructures which, in combination with a surprising chemical hydrophilicity of the cuticle waxes, render the bug almost superhydrophilic: water spreads immediately across the surface. We could theoretically model this behaviour assuming the effect of hemi-wicking (a state in which a droplet sits on a rough surface, partwise imbibing the structure around).  Additionally the principle was abstracted and a laser-patterned polymer surface, mimicking the structure and contact angle of Dysodius wax, shows exactly the behaviour of the natural role model - immediate spreading of water and the formation of a thin continuous water film changing optical properties of the surface. © 2017. Published by The Company of Biologists Ltd.

  3. Choosing between a rock and a hard place: Camouflage in the round-tailed horned lizard Phrynosoma modestum

    Directory of Open Access Journals (Sweden)

    William E. COOPER, Jr., Wade C. SHERBROOKE

    2012-08-01

    Full Text Available The round-tailed horned lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back. We investigated effectiveness of camouflage in P. modestum and its dependence on stones by placing a lizard in one of two microhabitats (uniform sand or sand with surface rocks approximately the same size as lizards. An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually. Latency to detection was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand. In arenas where lizards could choose to occupy rock or bare sand, much higher proportions selected rocky backgrounds throughout the day; at night all lizards slept among stones. A unique posture gives P. modestum a rounded appearance similar to many natural stones. Lizards occasionally adopted the posture, but none did so in response to a nearby experimenter. Stimuli that elicit the posture are unknown. That P. modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks (masquerade enhances camouflage attributable to coloration and immobility [Current Zoology 58 (4: 541–548, 2012].

  4. Heterosexual Rejection and Mate Choice: A Sociometer Perspective

    Directory of Open Access Journals (Sweden)

    Lin eZHANG

    2015-12-01

    Full Text Available Previous studies about the effects of social rejection on individuals’ social behaviors have produced mixed results and tend to study mating behaviors from a static point of view. However, mate selection in essence is a dynamic process, and therefore sociometer theory opens up a new perspective for studying mating and its underlying practices. Based on this theory and using self-perceived mate value in the relationship between heterosexual rejection and mate choice as a mediating role, this current study examined the effects of heterosexual rejection on mate choice in two experiments. Results showed that heterosexual rejection significantly reduced self-perceived mate value, expectation, and behavioral tendencies, while heterosexual acceptance indistinctively increased these measures. Self-perceived mate value did not serve as a mediator in the relationship between heterosexual rejection and mate expectation, but it mediated the relationship between heterosexual rejection and mating behavior tendencies towards potential objects. Moreover, individuals evaded both rejection and irrelevant people when suffering from rejection.

  5. Habit in Personality and Social Psychology.

    Science.gov (United States)

    Wood, Wendy

    2017-11-01

    Habits are largely absent from modern social and personality psychology. This is due to outdated perspectives that placed habits in conflict with goals. In modern theorizing, habits are represented in memory as implicit context-response associations, and they guide responding in conjunction with goals. Habits thus have important implications for our field. Emerging research shows that habits are an important mechanism by which people self-regulate and achieve long-term goals. Also, habits change through specific interventions, such as changes in context cues. I speculate that understanding of habits also holds promise for reducing intergroup discrimination and for understanding lay theories of the causes for action. In short, by recognizing habit, the field gains understanding of a central mechanism by which actions persist in daily life.

  6. Smoking habits among atomic-bomb survivors

    International Nuclear Information System (INIS)

    Akiba, Suminori; Kimura, Masafumi

    1992-01-01

    The Radiation Effects Research Foundation made a research through mailing, the smoking habits among the A-bomb survivors in 1978-79. Statistic analysis was made on the smoking habits and radiation doses. (J.P.N.)

  7. The rules of coherence and other habits

    OpenAIRE

    Solis, M. R. C.

    2003-01-01

    Physics and mathematics are difficult enough without the aditional burden of bad habits. In this article, we examine some helpful habits that tend to be underemphasized by many physics teachers (mainly because they seem so obvious!).

  8. Constellation Architecture Team-Lunar Scenario 12.0 Habitation Overview

    Science.gov (United States)

    Kennedy, Kriss J.; Toups, Larry D.; Rudisill, Marianne

    2010-01-01

    This paper will describe an overview of the Constellation Architecture Team Lunar Scenario 12.0 (LS-12) surface habitation approach and concept performed during the study definition. The Lunar Scenario 12 architecture study focused on two primary habitation approaches: a horizontally-oriented habitation module (LS-12.0) and a vertically-oriented habitation module (LS-12.1). This paper will provide an overview of the 12.0 lunar surface campaign, the associated outpost architecture, habitation functionality, concept description, system integration strategy, mass and power resource estimates. The Scenario 12 architecture resulted from combining three previous scenario attributes from Scenario 4 "Optimized Exploration", Scenario 5 "Fission Surface Power System" and Scenario 8 "Initial Extensive Mobility" into Scenario 12 along with an added emphasis on defining the excursion ConOps while the crew is away from the outpost location. This paper will describe an overview of the CxAT-Lunar Scenario 12.0 habitation concepts and their functionality. The Crew Operations area includes basic crew accommodations such as sleeping, eating, hygiene and stowage. The EVA Operations area includes additional EVA capability beyond the suitlock function such as suit maintenance, spares stowage, and suit stowage. The Logistics Operations area includes the enhanced accommodations for 180 days such as enhanced life support systems hardware, consumable stowage, spares stowage, interconnection to the other habitation elements, a common interface mechanism for future growth, and mating to a pressurized rover or Pressurized Logistics Module (PLM). The Mission & Science Operations area includes enhanced outpost autonomy such as an IVA glove box, life support, medical operations, and exercise equipment.

  9. Oral Habits That Cause Malocclusion Problems

    OpenAIRE

    Joelijanto, Rudy

    2012-01-01

    Oral habits that place pressure on the teeth may slowly move the teeth out of place. The aim of this study was to review the literature for articles referring the most common oral habits that cause malocclusion. The oral bad habits that cause malocclussion problems include: Thumb sucking, It is a normal habit for babies, but causes serious orthodontic problems if it continues long after the eruption of permanent teeth. Prolonged thumb sucking can create crowded, crooked teeth, or bite problem...

  10. Sampling and assessment accuracy in mate choice: a random-walk model of information processing in mating decision.

    Science.gov (United States)

    Castellano, Sergio; Cermelli, Paolo

    2011-04-07

    Mate choice depends on mating preferences and on the manner in which mate-quality information is acquired and used to make decisions. We present a model that describes how these two components of mating decision interact with each other during a comparative evaluation of prospective mates. The model, with its well-explored precedents in psychology and neurophysiology, assumes that decisions are made by the integration over time of noisy information until a stopping-rule criterion is reached. Due to this informational approach, the model builds a coherent theoretical framework for developing an integrated view of functions and mechanisms of mating decisions. From a functional point of view, the model allows us to investigate speed-accuracy tradeoffs in mating decision at both population and individual levels. It shows that, under strong time constraints, decision makers are expected to make fast and frugal decisions and to optimally trade off population-sampling accuracy (i.e. the number of sampled males) against individual-assessment accuracy (i.e. the time spent for evaluating each mate). From the proximate-mechanism point of view, the model makes testable predictions on the interactions of mating preferences and choosiness in different contexts and it might be of compelling empirical utility for a context-independent description of mating preference strength. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Studies on mating competition of irradiated melon flies

    International Nuclear Information System (INIS)

    Limohpasmanee, W.

    1994-01-01

    Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

  12. Mate choice in fruit flies is rational and adaptive.

    Science.gov (United States)

    Arbuthnott, Devin; Fedina, Tatyana Y; Pletcher, Scott D; Promislow, Daniel E L

    2017-01-17

    According to rational choice theory, beneficial preferences should lead individuals to sort available options into linear, transitive hierarchies, although the extent to which non-human animals behave rationally is unclear. Here we demonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of a set of diverse isogenic female lines, unambiguously demonstrating the hallmark of rational behaviour, transitivity. These rational choices are associated with direct benefits, enabling males to maximize offspring production. Furthermore, we demonstrate that female behaviours and cues act redundantly in mate detection and assessment, as rational mate choice largely persists when visual or chemical sensory modalities are impaired, but not when both are impaired. Transitivity in mate choice demonstrates that the quality of potential mates varies significantly among genotypes, and that males and females behave in such a way as to facilitate adaptive mate choice.

  13. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  14. Mate extract as feed additive for improvement of beef quality

    DEFF Research Database (Denmark)

    de Zawadzki, Andressa; Arrivetti, Leandro de O.R.; Vidal, Marília P.

    2017-01-01

    Mate (Ilex paraguariensis A.St.-Hil.) is generally recognized as safe (GRAS status) and has a high content of alkaloids, saponins, and phenolic acids. Addition of mate extract to broilers feed has been shown to increase the oxidative stability of chicken meat, however, its effect on beef quality...... from animals supplemented with mate extract has not been investigated so far. Addition of extract of mate to a standard maize/soy feed at a level of 0.5, 1.0 or 1.5% w/w to the diet of feedlot for cattle resulted in increased levels of inosine monophosphate, creatine and carnosine in the fresh meat....... The content of total conjugated linoleic acid increased in the meat as mate extract concentration was increased in the feed. The tendency to radical formation in meat slurries as quantified by EPR spin-trapping decreased as increasing mate extract addition to feed, especially after storage of the meat...

  15. Inline Electrical Connector Mate/Demate Pliers

    Science.gov (United States)

    Yutko, Brian; Dininny, Michael; Moscoso, Gerand; Dokos, Adam

    2010-01-01

    Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.

  16. Sex allocation predicts mating rate in a simultaneous hermaphrodite

    OpenAIRE

    Janicke, Tim; Schärer, Lukas

    2009-01-01

    Sexual selection theory for separate-sexed animals predicts that the sexes differ in the benefit they can obtain from multiple mating. Conventional sex roles assume that the relationship between the number of mates and the fitness of an individual is steeper in males compared with females. Under these conditions, males are expected to be more eager to mate, whereas females are expected to be choosier. Here we hypothesize that the sex allocation, i.e. the reproductive investment devoted to the...

  17. Modelling the evolution and consequences of mate choice

    OpenAIRE

    Tazzyman, S. J.

    2010-01-01

    This thesis considers the evolution and the consequences of mate choice across a variety of taxa, using game theoretic, population genetic, and quantitative genetic modelling techniques. Part I is about the evolution of mate choice. In chapter 2, a population genetic model shows that mate choice is even beneficial in self-fertilising species such as Saccharomyces yeast. In chapter 3, a game theoretic model shows that female choice will be strongly dependent upon whether the benefi...

  18. Mate Selection in Contemporary America: An Exchange Theory Perspective

    OpenAIRE

    Young, Margaret H.

    1989-01-01

    The use of exchange theory as it applies to human relations has escalated dramatically in the past 20 years. The present study applies exchange theory as the basis of mate selection in contemporary society. Whereas an actual barter system was used in the past and families played a major role in choosing prospective mates, participants in the mate selection process are not virtually on their own and must rely upon their own bargaining skills to present their assets on the marriage market. A...

  19. Narcissism and the Strategic Pursuit of Short-Term Mating

    DEFF Research Database (Denmark)

    Schmitt, David P.; Alcalay, Lidia; Allik, Jüri

    2017-01-01

    Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the curr...... limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating....

  20. Habits, aspirations and endogenous fertility

    OpenAIRE

    Luciano Fanti

    2012-01-01

    Motivated by the increasing literature on endogenous preferences as well as on endogenous fertility, this paper investigates the implications of the interaction of the endogenous determination of the number of children with habit and aspiration formation in an OLG model. In contrast with the previous literature, we show that greater aspirations may lead to higher savings, and more interestingly, always increase the neoclassical economic growth.

  1. Drug Advertising and Health Habit

    OpenAIRE

    Toshiaki Iizuka; Ginger Zhe Jin

    2005-01-01

    We examine the effect of direct-to-consumer advertising (DTCA) of drug treatment on an important health habit, physical exercise. By learning the existence of a new drug treatment via DTCA, rational consumers may become careless about maintaining healthy lifestyles. Using the National Health Insurance Survey (NHIS) and MSA-level DTCA data, we find that the DTCA related to four chronic conditions -- diabetes, high cholesterol, over weight, and hypertension -- reduce the likelihood of engaging ...

  2. Widen the belt of habitability!

    Science.gov (United States)

    Möhlmann, D

    2012-06-01

    Among the key-parameters to characterize habitability are presence or availability of liquid water, an appropriate temperature range, and the time scale of reference. These criteria for habitability are discussed and described from the point of view of water- and ice-physics, and it is shown that liquid water may exist in the sub-surfaces of planetary bodies like Mars, and possibly of inner asteroids and internally heated ice-moons. Water can remain fluid there also at temperatures far below the "canonical" 0 °C. This behaviour is made possible as a consequence of the freezing point depression due to salty solutes in water or "brines", as they can be expected to exist in nature more frequently than pure liquid water. On the other hand, low temperatures cause a slowing down of chemical processes, as can be described by Arrhenius's relation. The resulting smaller reaction rates probably will have the consequence to complicate the detection of low-temperature life processes, if they exist. Furthermore, the adaptation potential of life is to be mentioned in this context as a yet partially unknown process. Resulting recommendations are given to improve the use of criteria to characterize habitable conditions.

  3. Mate Choice Drives Evolutionary Stability in a Hybrid Complex.

    Directory of Open Access Journals (Sweden)

    Miguel Morgado-Santos

    Full Text Available Previous studies have shown that assortative mating acts as a driver of speciation by countering hybridization between two populations of the same species (pre-zygotic isolation or through mate choice among the hybrids (hybrid speciation. In both speciation types, assortative mating promotes speciation over a transient hybridization stage. We studied mate choice in a hybrid vertebrate complex, the allopolyploid fish Squalius alburnoides. This complex is composed by several genomotypes connected by an intricate reproductive dynamics. We developed a model that predicts the hybrid complex can persist when females exhibit particular mate choice patterns. Our model is able to reproduce the diversity of population dynamic outcomes found in nature, namely the dominance of the triploids and the dominance of the tetraploids, depending on female mate choice patterns and frequency of the parental species. Experimental mate choice trials showed that females exhibit the preferences predicted by the model. Thus, despite the known role of assortative mating in driving speciation, our findings suggest that certain mate choice patterns can instead hinder speciation and support the persistence of hybrids over time without speciation or extinction.

  4. Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

    Science.gov (United States)

    Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

    2014-01-01

    Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments. PMID:24805129

  5. Sexual experience enhances Drosophila melanogaster male mating behavior and success.

    Directory of Open Access Journals (Sweden)

    Sehresh Saleem

    Full Text Available Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments.

  6. Personality and mate preferences: five factors in mate selection and marital satisfaction.

    Science.gov (United States)

    Botwin, M D; Buss, D M; Shackelford, T K

    1997-03-01

    Although personality characteristics figure prominently in what people want in a mate, little is known about precisely which personality characteristics are most important, whether men and women differ in their personality preferences, whether individual women or men differ in what they want, and whether individuals actually get what they want. To explore these issues, two parallel studies were conducted, one using a sample of dating couples (N = 118) and one using a sample of married couples (N = 216). The five-factor model, operationalized in adjectival form, was used to assess personality characteristics via three data sources-self--report, partner report, and independent interviewer reports. Participants evaluated on a parallel 40-item instrument their preferences for the ideal personality characteristics of their mates. Results were consistent across both studies. Women expressed a greater preference than men for a wide array of socially desirable personality traits. Individuals differed in which characteristics they desired, preferring mates who were similar to themselves and actually obtaining mates who embodied what they desired. Finally, the personality characteristics of one's partner significantly predicted marital and sexual dissatisfaction, most notably when the partner was lower on Agreeableness, Emotional Stability, and Intellect-Openness than desired.

  7. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    DST Unit on Evolution and Genetics, Department of Studies in Zoology, University of Mysore, Manasagangotri,. Mysore 570 006, India .... using SPSS software (ver. 16.0). Results ... Proportions of first male and second male progeny of doubly mated female and the results of paired-sample t-test carried out independently for ...

  8. Are high-quality mates always attractive? State-dependent mate preferences in birds and humans

    NARCIS (Netherlands)

    Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W.

    2010-01-01

    Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources

  9. Co-occurrence of mated workers and a mated queen in a colony of ...

    African Journals Online (AJOL)

    arnoldi (Hymenoptera: Formicidae). Martin Villet *. Department of Zoology, University of the Witwatersrand, P.O.. Wits, 2050 Republic of South Africa. Received 23 March 1992; accepted 8 June 1992. A colony of Platythyrea arnold; was found to contain a functional queen and laying workers, both virgin and mated. This form ...

  10. [Significance of bad habits in orthodontics].

    Science.gov (United States)

    Tarján, Ildikó

    2002-08-01

    The author is concerned with the etiological role of bad habits in the development. Disturbances caused by pacifier habits, finger sucking, various forms of swallowing habits and their therapeutical possibilities are discussed. The role of mouth breathing, nail biting, bruxism and self-mutilation in development of anomalies and their therapy are also mentioned. The attention is called to the fact that dentists have responsibility and task to diagnose as early as can be the oral bad habits and that the adequate therapy in time in co-operation with other specialists helping the child get out of bad habits, preventing the development of severe anomaly.

  11. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  12. Assortative Mating by Ethnicity in Longevous Families

    Directory of Open Access Journals (Sweden)

    Paola Sebastiani

    2017-11-01

    Full Text Available Recent work shows strong evidence of ancestry-based assortative mating in spouse pairs of the older generation of the Framingham Heart Study. Here, we extend this analysis to two studies of human longevity: the Long Life Family Study (LLFS, and the New England Centenarian Study (NECS. In the LLFS, we identified 890 spouse pairs spanning two generations, while in the NECS we used data from 102 spouse pairs including offspring of centenarians. We used principal components of genome-wide genotype data to demonstrate strong evidence of ancestry-based assortative mating in spouse pairs of the older generation and also confirm the decreasing trend of endogamy in more recent generations. These findings in studies of human longevity suggest that spouses marrying into longevous families may not be powerful controls for genetic association studies, and that there may be important ethnicity-specific, genetic influences and/or gene–environment interactions that influence extreme survival in old generations. In addition, the decreasing trend of genetic similarity of more recent generations might have ramifications for the incidence of homozygous rare variants necessary for survival to the most extreme ages.

  13. Assortative Mating by Ethnicity in Longevous Families.

    Science.gov (United States)

    Sebastiani, Paola; Gurinovich, Anastasia; Bae, Harold; Andersen, Stacy L; Perls, Thomas T

    2017-01-01

    Recent work shows strong evidence of ancestry-based assortative mating in spouse pairs of the older generation of the Framingham Heart Study. Here, we extend this analysis to two studies of human longevity: the Long Life Family Study (LLFS), and the New England Centenarian Study (NECS). In the LLFS, we identified 890 spouse pairs spanning two generations, while in the NECS we used data from 102 spouse pairs including offspring of centenarians. We used principal components of genome-wide genotype data to demonstrate strong evidence of ancestry-based assortative mating in spouse pairs of the older generation and also confirm the decreasing trend of endogamy in more recent generations. These findings in studies of human longevity suggest that spouses marrying into longevous families may not be powerful controls for genetic association studies, and that there may be important ethnicity-specific, genetic influences and/or gene-environment interactions that influence extreme survival in old generations. In addition, the decreasing trend of genetic similarity of more recent generations might have ramifications for the incidence of homozygous rare variants necessary for survival to the most extreme ages.

  14. Camouflage through an active choice of a resting spot and body orientation in moths.

    Science.gov (United States)

    Kang, C-K; Moon, J-Y; Lee, S-I; Jablonski, P G

    2012-09-01

    Cryptic colour patterns in prey are classical examples of adaptations to avoid predation, but we still know little about behaviours that reinforce the match between animal body and the background. For example, moths avoid predators by matching their colour patterns with the background. Active choice of a species-specific body orientation has been suggested as an important function of body positioning behaviour performed by moths after landing on the bark. However, the contribution of this behaviour to moths' crypticity has not been directly measured. From observations of geometrid moths, Hypomecis roboraria and Jankowskia fuscaria, we determined that the positioning behaviour, which consists of walking and turning the body while repeatedly lifting and lowering the wings, resulted in new resting spots and body orientations in J. fuscaria and in new resting spots in H. roboraria. The body positioning behaviour of the two species significantly decreased the probability of visual detection by humans, who viewed photographs of the moths taken before and after the positioning behaviour. This implies that body positioning significantly increases the camouflage effect provided by moth's cryptic colour pattern regardless of whether the behaviour involves a new body orientation or not. Our study demonstrates that the evolution of morphological adaptations, such as colour pattern of moths, cannot be fully understood without taking into account a behavioural phenotype that coevolved with the morphology for increasing the adaptive value of the morphological trait. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  15. Orthodontic camouflage in the case of a skeletal class III malocclusion.

    Science.gov (United States)

    Costa Pinho, Teresa M; Ustrell Torrent, Josep M; Correia Pinto, João G R

    2004-01-01

    To describe the clinical problem of a male patient, 15 years of age, who had a dolichofacial biotype and a Class III skeletal type at the beginning of treatment, manifesting itself at the dental level. To resolve the dental problems, orthodontic camouflage (dentoalveolar compensation) with the extraction of two mandibular premolars was performed. This procedure allowed a more harmonious occlusal relationship at the canine level and provided better occlusal stability of the final result. The procedure choice was based on the fact that some cephalometric values were favorable to attenuation of the skeletal Class III. For example, according to the analyses of Björk and Jarabak, these values are the total sum of 1, 2, 3 (sella angle, articular angle, and gonial angles) and the anterior/posterior facial height (S-Go/Na-Me). However, the same cephalometric data indicate a possible worsening of the existing open bite, which might be corrected with dental extractions and the use of intermaxillary elastics.

  16. Successful and stable orthodontic camouflage of a mandibular asymmetry with sliding jigs.

    Science.gov (United States)

    Oliveira, Dauro Douglas; Oliveira, Bruno Franco de; Mordente, Carolina Morsani; Godoy, Gabriela Martins; Soares, Rodrigo Villamarim; Seraidarian, Paulo Isaías

    2018-03-12

    The purpose of this paper is to present and discuss a simple and low-cost clinical approach to correct an asymmetric skeletal Class III combined to an extensive dental open bite that significantly compromised the occlusal function and smile aesthetics of an adult male patient. The patient did not accept the idealistic surgical-orthodontic treatment option, neither the use of temporary anchorage devices to facilitate the camouflage of the asymmetrical skeletal Class III/open bite. Therefore, a very simple and inexpensive biomechanical approach using sliding jigs in the mandibular arch was implemented as the compensatory treatment of the malocclusion. Although minor enhancements in facial aesthetics were obtained, the occlusal function and dental aesthetics were significantly improved. Furthermore, the patient was very satisfied with his new smile appearance. Some advantages of this treatment option included the small invasiveness and the remarkably low financial costs involved. Moreover, the final results fulfilled all realistic treatment objectives and the patient's expectations. Results remained stable 5 years post-treatment demonstrating that excellent results can be obtained when simple and low cost, but well-controlled mechanics are conducted.

  17. Treatment in Borderline Class III Malocclusion: Orthodontic Camouflage (Extraction) Versus Orthognathic Surgery.

    Science.gov (United States)

    Rabie, A-Bakr M; Wong, Ricky W K; Min, G U

    2008-01-01

    To investigate the differences in morphological characteristics of borderline class III patients who had undergone camouflage orthodontic treatment or orthognathic surgery, and to compare the treatment effects between these two modalities. Cephalograms of 25 patients (13 orthodontic, 12 surgical) with class III malocclusion were analyzed. All had a pretreatment ANB angle greater than -5 masculine. Using discriminant analysis, only Holdaway angle was selected to differentiate patients in the pretreatment stage. Seventy-two per cent patients were correctly classified. In the orthodontic group, reverse overjet was corrected by retraction of the lower incisors and downward and backward rotation of the mandible. The surgical group was corrected by setback of the lower anterior dentoalveolus and uprighting of the lower incisors. No difference was found in posttreatment soft tissue measurements between the two groups. Twelve degree for the Holdaway angle can be a guideline in determining the treatment modalities for borderline class III patients, but the preferences of operators and patients are also important. (2) Both therapeutic options should highlight changes in the lower dentoalveolus and lower incisors. (3) Both treatment modalities can achieve satisfactory improvements to the people.

  18. Treatment of skeletal Class III malocclusions: orthognathic surgery or orthodontic camouflage? How to decide.

    Science.gov (United States)

    Benyahia, Hicham; Azaroual, Mohamed Faouzi; Garcia, Claude; Hamou, Edith; Abouqal, Redouane; Zaoui, Fatima

    2011-06-01

    The choice of treatment in adult skeletal Class III occlusions often poses a particularly tricky problem for the orthodontist. Faced with the option of either orthodontic camouflage or orthognathic surgery, the clinician's clinical experience is of paramount importance, especially in borderline cases. The aim of our study was to uncover a guide model enabling the practitioner to distinguish between skeletal Class III cases which can be suitably treated with orthodontics and those requiring orthognathic surgery. The lateral headfilms of 47 adult patients exhibiting skeletal Class III occlusions were analyzed. The orthodontic group comprised 22 patients and the surgical group 25. Twenty-seven linear, proportional and angular measurements were scrutinized. Stepwise discriminant analysis was used to identify the dentoskeletal and esthetic variables which most distinguished the two groups. The Holdaway angle was chosen to differentiate between patients prior to treatment. This model enables us to classify 87.2% of patients correctly. Copyright © 2011 CEO. Published by Elsevier Masson SAS. All rights reserved.

  19. [Limiting factors in the class III camouflage treatment: a potential protocol].

    Science.gov (United States)

    Chaques Asensi, José

    2016-06-01

    The Class III skeletal malocclusion has been traditionally treated with a combined approach of orthodontics and orthognathic surgery or with a strategy of orthodontic camouflage. Some severe cases can be identified as ideal candidates for a surgical treatment whereas some others can be handled with orthodontics alone, with a reasonable expectation of an acceptable result. However, the problem remains for the borderline patient. In fact, limited information is available in the literature regarding the identification of the factors that can help in establishing the limits for one treatment modality or the other. Furthermore, the quantification of some of these factors, for practical purposes, is practically missing or very seldom suggested. Therefore, the decision making process remains a subjective reflection based on the "good clinical sense" of the orthodontist or just reduced to an "educated guess". In order to add some information, hopefully useful in deciding the most suitable treatment option for the individual patient, we propose a clinical protocol based on four different factors. Namely: the skeletal discrepancy, the occlusal discrepancy, the periodontal condition and facial aesthetics. For each one of these factors several parameters will be evaluated and, for some of them, an attempt to provide some reference numerical values will be made. Finally, clinical examples will be presented to illustrate the concepts discussed and the treatment alternatives, final treatment plan and treatment outcome will be analyzed for each one of them. © EDP Sciences, SFODF, 2016.

  20. Red blood cell membrane-camouflaged melanin nanoparticles for enhanced photothermal therapy.

    Science.gov (United States)

    Jiang, Qin; Luo, Zimiao; Men, Yongzhi; Yang, Peng; Peng, Haibao; Guo, Ranran; Tian, Ye; Pang, Zhiqing; Yang, Wuli

    2017-10-01

    Photothermal therapy (PTT) has represented a promising noninvasive approach for cancer treatment in recent years. However, there still remain challenges in developing non-toxic and biodegradable biomaterials with high photothermal efficiency in vivo. Herein, we explored natural melanin nanoparticles extracted from living cuttlefish as effective photothermal agents and developed red blood cell (RBC) membrane-camouflaged melanin (Melanin@RBC) nanoparticles as a platform for in vivo antitumor PTT. The as-obtained natural melanin nanoparticles demonstrated strong absorption at NIR region, higher photothermal conversion efficiency (∼40%) than synthesized melanin-like polydopamine nanoparticles (∼29%), as well as favorable biocompatibility and biodegradability. It was shown that RBC membrane coating on melanin nanoparticles retained their excellent photothermal property, enhanced their blood retention and effectively improved their accumulation at tumor sites. With the guidance of their inherited photoacoustic imaging capability, optimal accumulation of Melanin@RBC at tumors was achieved around 4 h post intravenous injection. Upon irradiation by an 808-nm laser, the developed Melanin@RBC nanoparticles exhibited significantly higher PTT efficacy than that of bare melanin nanoparticles in A549 tumor-bearing mice. Given that both melanin nanoparticles and RBC membrane are native biomaterials, the developed Melanin@RBC platform could have great potential in clinics for anticancer PTT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Long-range depth profiling of camouflaged targets using single-photon detection

    Science.gov (United States)

    Tobin, Rachael; Halimi, Abderrahim; McCarthy, Aongus; Ren, Ximing; McEwan, Kenneth J.; McLaughlin, Stephen; Buller, Gerald S.

    2018-03-01

    We investigate the reconstruction of depth and intensity profiles from data acquired using a custom-designed time-of-flight scanning transceiver based on the time-correlated single-photon counting technique. The system had an operational wavelength of 1550 nm and used a Peltier-cooled InGaAs/InP single-photon avalanche diode detector. Measurements were made of human figures, in plain view and obscured by camouflage netting, from a stand-off distance of 230 m in daylight using only submilliwatt average optical powers. These measurements were analyzed using a pixelwise cross correlation approach and compared to analysis using a bespoke algorithm designed for the restoration of multilayered three-dimensional light detection and ranging images. This algorithm is based on the optimization of a convex cost function composed of a data fidelity term and regularization terms, and the results obtained show that it achieves significant improvements in image quality for multidepth scenarios and for reduced acquisition times.

  2. Open water camouflage via 'leaky' light guides in the midwater squid Galiteuthis.

    Science.gov (United States)

    Holt, Amanda L; Sweeney, Alison M

    2016-06-01

    Galiteuthis, a midwater squid, has photophores on the ventral surfaces of its eyes. These photophores emit bioluminescence to counter-illuminate the shadows cast by the eyes in downwelling sunlight, thereby hiding the eyes from upward-looking predators. The photophores consist of laminated fibre-like cells with semi-coaxial protein-dense layers around axial cytoplasm. These cells have been suggested to function as light guides: bioluminescence is an isotropic process used to hide in an anisotropic light environment, so any emission must be reshaped to be effective. We found a wide variation in cross-sectional geometries of photophore cells; some were more efficient at light guiding than others. We used a set of optical models to place these photophores in the context of the radiance where Galiteuthis lives and discovered a possible adaptive reason for this variation. In Galiteuthis's horizontal and vertical range, ocean radiance is also quite variable. For complete camouflage, photophores must reproduce this variation in radiance using an isotropic source. Our models show that variation in the geometry of the photophore light guides reproduces the predicted variation in ocean radiance experienced by this species. By selectively activating geometrically distinct populations of photophore cells, the animal may reproduce the angular distribution of light at all positions in its habitat. © 2016 The Author(s).

  3. Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage

    Science.gov (United States)

    Zimova, Marketa; Mills, L. Scott; Lukacs, Paul M.; Mitchell, Michael S.

    2014-01-01

    As duration of snow cover decreases owing to climate change, species undergoing seasonal colour moults can become colour mismatched with their background. The immediate adaptive solution to this mismatch is phenotypic plasticity, either in phenology of seasonal colour moults or in behaviours that reduce mismatch or its consequences. We observed nearly 200 snowshoe hares across a wide range of snow conditions and two study sites in Montana, USA, and found minimal plasticity in response to mismatch between coat colour and background. We found that moult phenology varied between study sites, likely due to differences in photoperiod and climate, but was largely fixed within study sites with only minimal plasticity to snow conditions during the spring white-to-brown moult. We also found no evidence that hares modify their behaviour in response to colour mismatch. Hiding and fleeing behaviours and resting spot preference of hares were more affected by variables related to season, site and concealment by vegetation, than by colour mismatch. We conclude that plasticity in moult phenology and behaviours in snowshoe hares is insufficient for adaptation to camouflage mismatch, suggesting that any future adaptation to climate change will require natural selection on moult phenology or behaviour.

  4. Theory of transformation thermal convection for creeping flow in porous media: Cloaking, concentrating, and camouflage

    Science.gov (United States)

    Dai, Gaole; Shang, Jin; Huang, Jiping

    2018-02-01

    Heat can transfer via thermal conduction, thermal radiation, and thermal convection. All the existing theories of transformation thermotics and optics can treat thermal conduction and thermal radiation, respectively. Unfortunately, thermal convection has seldom been touched in transformation theories due to the lack of a suitable theory, thus limiting applications associated with heat transfer through fluids (liquid or gas). Here, we develop a theory of transformation thermal convection by considering the convection-diffusion equation, the equation of continuity, and the Darcy law. By introducing porous media, we get a set of equations keeping their forms under coordinate transformation. As model applications, the theory helps to show the effects of cloaking, concentrating, and camouflage. Our finite-element simulations confirm the theoretical findings. This work offers a transformation theory for thermal convection, thus revealing novel behaviors associated with potential applications; it not only provides different hints on how to control heat transfer by combining thermal conduction, thermal convection, and thermal radiation, but also benefits mass diffusion and other related fields that contain a set of equations and need to transform velocities at the same time.

  5. Uncovering Camouflage: Amygdala Activation Predicts Long-Term Memory of Induced Perceptual Insight

    Science.gov (United States)

    Ludmer, Rachel; Dudai, Yadin; Rubin, Nava

    2012-01-01

    What brain mechanisms underlie learning of new knowledge from single events? We studied encoding in long-term memory of a unique type of one-shot experience, induced perceptual insight. While undergoing an fMRI brain scan, participants viewed degraded images of real-world pictures where the underlying objects were hard to recognize (‘camouflage’), followed by brief exposures to the original images (‘solution’), which led to induced insight (“Aha!”). A week later, participants’ memory was tested; a solution image was classified as ‘remembered’ if detailed perceptual knowledge was elicited from the camouflage image alone. During encoding, subsequently remembered images enjoyed higher activity in mid-level visual cortex and medial frontal cortex, but most pronouncedly in the amygdala, whose activity could be used to predict which solutions will remain in long-term memory. Our findings extend the known roles of amygdala in memory to include promoting of long-term memory of the sudden reorganization of internal representations. PMID:21382558

  6. Synthetic nanoparticles camouflaged with biomimetic erythrocyte membranes for reduced reticuloendothelial system uptake

    International Nuclear Information System (INIS)

    Rao, Lang; Xu, Jun-Hua; Cai, Bo; Liu, Huiqin; Li, Ming; Jia, Yan; Xiao, Liang; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

    2016-01-01

    Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to great success in this respect. Nevertheless, recent observations of immunological response toward these synthetic polymers have triggered a search for better alternatives. In this work, natural red blood cell (RBC) membranes are camouflaged on the surface of Fe 3 O 4 nanoparticles for reducing the RES uptake. In vitro macrophage uptake, in vivo biodistribution and pharmacokinetic studies demonstrate that the RBC membrane is a superior alternative to the current gold standard PEG for nanoparticle ‘stealth’. Furthermore, we systematically investigate the in vivo potential toxicity of RBC membrane-coated nanoparticles by blood biochemistry, whole blood panel examination and histology analysis based on animal models. The combination of synthetic nanoparticles and natural cell membranes embodies a novel and biomimetic nanomaterial design strategy and presents a compelling property of functional materials for a broad range of biomedical applications. (paper)

  7. Climate change is affecting mortality of weasels due to camouflage mismatch.

    Science.gov (United States)

    Atmeh, Kamal; Andruszkiewicz, Anna; Zub, Karol

    2018-05-24

    Direct phenological mismatch caused by climate change can occur in mammals that moult seasonally. Two colour morphs of the weasel Mustela nivalis (M. n.) occur sympatrically in Białowieża Forest (NE Poland) and differ in their winter pelage colour: white in M. n. nivalis and brown in M. n. vulgaris. Due to their small body size, weasels are vulnerable to attacks by a range of different predators; thus cryptic coat colour may increase their winter survival. By analysing trapping data, we found that the share of white subspecies in the weasel population inhabiting Białowieża Forest decreases with decreasing numbers of days with snow cover. This led us to hypothesise that selective predation pressure should favour one of the two phenotypes, according to the prevailing weather conditions in winter. A simple field experiment with weasel models (white and brown), exposed against different background colours, revealed that contrasting models faced significantly higher detection by predators. Our observations also confirmed earlier findings that the plasticity of moult in M. n. nivalis is very limited. This means that climate change will strongly influence the mortality of the nivalis-type due to prolonged camouflage mismatch, which will directly affect the abundance and geographical distribution of this subspecies.

  8. Planning to break unwanted habits: habit strength moderates implementation intention effects on behaviour change.

    Science.gov (United States)

    Webb, Thomas L; Sheeran, Paschal; Luszczynska, Aleksandra

    2009-09-01

    Implementation intention formation promotes effective goal striving and goal attainment. However, little research has investigated whether implementation intentions promote behaviour change when people possess strong antagonistic habits. Experiment 1 developed relatively habitual responses that, after a task switch, had a detrimental impact on task performance. Forming an if-then plan reduced the negative impact of habit on performance. However, the effect of forming implementation intentions was smaller among participants who possessed strong habits as compared to participants who had weaker habits. Experiment 2 provided a field test of the role of habit strength in moderating the relationship between implementation intentions and behaviour in the context of smoking. Implementation intentions reduced smoking among participants with weak or moderate smoking habits, but not among participants with strong smoking habits. In summary, habit strength moderates the effectiveness of if-then plan formation in breaking unwanted habits.

  9. Smoking habit and gastritis histology.

    Science.gov (United States)

    Namiot, A; Kemona, A; Namiot, Z

    2007-01-01

    Long-term cigarette smoking may increase the risk of digestive tract pathologies, however, what is the influence smoking habit on gastric mucosa histology is still poorly elicited. The aim of the study was to compare histological evaluation of gastritis in smoker and non-smoker groups. A total of 236 patients of various H. pylori status (109 infected, 127 non-infected), clinical diagnosis (107 duodenal ulcer disease, 129 dyspepsia), and smoking habit (92 smokers, 144 non-smokers) were included. Subjects were classified as smokers if they smoked 5 or more cigarettes per day for at least 3 years. A histological examination of endoscopically obtained samples was performed by two experienced pathomorphologists blinded to the diagnoses and smoking habit. Microscopic slices of the gastric mucosa were stained with hematoxylin-eosin and Giemsa. Apart from histological diagnosis, H. pylori status was additionally confirmed by an urease test (CLO-test) at least in one of two gastric locations (antrum or corpus). In the H. pylori infected population, H. pylori density, neutrophils, and mononuclear cells infiltration in the gastric corpus mucosa were lower in smokers than non-smokers, while in the antrum the differences were not significant. In the non-infected population, no significant differences in neutrophils and mononuclear cells infiltration between smokers and non-smokers were found. Since the significant differences in studied parameters of chronic gastritis between smokers and non-smokers were found in the corpus mucosa of H. pylori infected subjects, smoking should be taken into account when a histological evaluation of the gastric mucosa in the H. pylori infected population is performed.

  10. The evolution of parent-offspring conflict over mate choice

    NARCIS (Netherlands)

    van den Berg, Pieter; Fawcett, Tim W.; Buunk, Abraham P.; Weissing, Franz J.

    2013-01-01

    In human societies, parents often have a strong influence on the mate choice of their offspring. Moreover, empirical studies show that conflict over mate choice between parents and offspring is widespread across human cultures. Here we provide the first theoretical investigation into this conflict,

  11. Genetic incompatibility drives mate choice in a parasitic wasp

    NARCIS (Netherlands)

    Thiel, A.; Weeda, A.C.; Boer, de J.G.; Hoffmeister, T.S.

    2013-01-01

    Introduction: Allelic incompatibility between individuals of the same species should select for mate choice based on the genetic make-up of both partners at loci that influence offspring fitness. As a consequence, mate choice may be an important driver of allelic diversity. A complementary sex

  12. Assortative mating for human height : A meta-analysis

    NARCIS (Netherlands)

    Stulp, Gert; Simons, Mirre J. P.; Grasman, Sara; Pollet, Thomas V.

    ObjectivesThe study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this

  13. Plant Mating Systems Often Vary Widely Among Populations

    Directory of Open Access Journals (Sweden)

    Michael R. Whitehead

    2018-04-01

    Full Text Available Most flowering plants are hermaphroditic, yet the proportion of seeds fertilized by self and outcross pollen varies widely among species, ranging from predominant self-fertilization to exclusive outcrossing. A population's rate of outcrossing has important evolutionary outcomes as it influences genetic structure, effective population size, and offspring fitness. Because most mating system studies have quantified outcrossing rates for just one or two populations, past reviews of mating system diversity have not been able to characterize the extent of variation among populations. Here we present a new database of more than 30 years of mating system studies that report outcrossing rates for three or more populations per species. This survey, which includes 741 populations from 105 species, illustrates substantial and prevalent among-population variation in the mating system. Intermediate outcrossing rates (mixed mating are common; 63% of species had at least one mixed mating population. The variance among populations and within species was not significantly correlated with pollination mode or phylogeny. Our review underscores the need for studies exploring variation in the relative influence of ecological and genetic factors on the mating system, and how this varies among populations. We conclude that estimates of outcrossing rates from single populations are often highly unreliable indicators of the mating system of an entire species.

  14. Mating system of the filamentous ascomycete, Glomerella cingulata.

    Science.gov (United States)

    Cisar, C R; TeBeest, D O

    1999-03-01

    Mating in heterothallic filamentous ascomycetes is typically controlled by a single mating-type locus with two alternate alleles or idiomorphs. In this study, five self-sterile strains of Glomerella cingulata from pecan were crossed in all possible combinations. Four of the five strains could be placed into two mating-type groups, but the fifth strain was sexually compatible with all of the other strains. Single ascospore progeny were isolated from each of the successful crosses, tested for self-fertility, and backcrossed with both parents. In addition, subsets of F1 isolates were crossed with all five of the original strains from pecan and in all possible combinations with each other. Results from the crosses showed that the ascospore progeny had stably inherited the mating pattern of one of the parental strains and that the mating type had segregated 1:1 among the F1 isolates. Furthermore, the five strains from pecan were sexually compatible with five additional heterothallic strains in all but one combination. Data from these experiments are consistent with a mating system composed of a single mating-type locus with multiple alternate alleles. We believe that this is the first report of this type of mating system for an ascomycete species.

  15. Gunner's Mate G 3 and 2; Rate Training Manual. Revised.

    Science.gov (United States)

    Naval Education and Training Command, Pensacola, FL.

    The rate training manual has been prepared for men of the regular Navy and of the Naval Reserve for the purpose of advancement to increase knowledge in the various aspects of the Gunner's Mate rating (G 3 and 2). Chapters 1 through 14 deal with the following topics: the requirements of the Gunner's Mate G Rating, explosives and pyrotechnics,…

  16. Mating flights select for symmetry in honeybee drones ( Apis mellifera)

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F. A.

    2010-03-01

    Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  17. Educational and social class assortative mating in fertile British couples.

    Science.gov (United States)

    Krzyżanowska, Monika; Mascie-Taylor, C G Nicholas

    2014-01-01

    Positive assortative mating for education and social position has been widely reported in a number of countries, but very few studies have tested whether or not educational or social class homogamy is related to differential fertility. This study examined the relationship between educational and social class assortative mating and fertility in a British national cohort. The analyses were based on 7452 husband-wife pairs from the British National Child Development Study (NCDS). The mean fertility was 3.22 children per couple; the number of children significantly increased from higher to lower social classes and from the more educated to the less educated. The extent of assortative mating for social class and educational level was related to fertility; as educational assortative mating decreased so did the average number of children, whereas the opposite trend was observed for social class. When assortative mating for education and social class were considered together, educational assortative mating was the more significant predictor of the number of children and educationally homogamous couples had higher fertility independent of their social class assortative mating. The relationship between assortative mating and fertility for education and social class appeared to be acting in the opposite direction.

  18. Mating flights select for symmetry in honeybee drones (Apis mellifera).

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F A

    2010-03-01

    Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  19. Mutual mate choice for olorful traits in King Penguins

    NARCIS (Netherlands)

    Nolan, Paul M.; Dobson, F. Stephen; Nicolaus, Marion; Karels, Tim J.; McGraw, Kevin J.; Jouventin, Pierre

    While studies of mate choice based on male color pattern are ubiquitous, studies of mate choice based on ornamental color traits in sexually monomorphic species are less common. We conducted manipulative field experiments on two color ornaments of king penguins (Aptenodytes patagonicus), the size of

  20. Mating duration and sperm precedence in the spider Linyphia triangularis

    DEFF Research Database (Denmark)

    Weldingh, Ditte L.; Toft, Søren; Larsen, Ole Næsbye

    2011-01-01

    , especially the males, are able to influence the outcome of mating for their own benefit. We studied the linyphiid spider Linyphia triangularis in which mating follows a strict sequence during which the male inducts two droplets of sperm and transfers them to the female. We performed sperm competition...

  1. Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels

    NARCIS (Netherlands)

    Zandberg, Elizabeth Christina; Gort, G.; van Oers, K.; Hinde, C.A.

    2017-01-01

    Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating

  2. Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels

    NARCIS (Netherlands)

    Zandberg, Lies; Gort, Gerrit; Oers, van Kees; Hinde, Camilla A.

    2017-01-01

    Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating

  3. Sex-specific conditional mating preferences in a cichlid fish : Implications for sexual conflict

    NARCIS (Netherlands)

    Baldauf, Sebastian A.; Engqvist, Leif; Ottenheym, Tobias; Bakker, Theo C. M.; Thuenken, Timo

    Conditional mating strategies enable individuals to modulate their mating behaviour depending on 'individual status' to maximise fitness. Theory predicts that variation in individual quality can lead to differences in mating preferences. However, empirical evidence is scarce particular in terms of

  4. SLE as a Mating of Trees in Euclidean Geometry

    Science.gov (United States)

    Holden, Nina; Sun, Xin

    2018-05-01

    The mating of trees approach to Schramm-Loewner evolution (SLE) in the random geometry of Liouville quantum gravity (LQG) has been recently developed by Duplantier et al. (Liouville quantum gravity as a mating of trees, 2014. arXiv:1409.7055). In this paper we consider the mating of trees approach to SLE in Euclidean geometry. Let {η} be a whole-plane space-filling SLE with parameter {κ > 4} , parameterized by Lebesgue measure. The main observable in the mating of trees approach is the contour function, a two-dimensional continuous process describing the evolution of the Minkowski content of the left and right frontier of {η} . We prove regularity properties of the contour function and show that (as in the LQG case) it encodes all the information about the curve {η} . We also prove that the uniform spanning tree on {Z^2} converges to SLE8 in the natural topology associated with the mating of trees approach.

  5. Women's Fertility Status Alters Other Women's Jealousy and Mate Guarding.

    Science.gov (United States)

    Hurst, Ashalee C; Alquist, Jessica L; Puts, David A

    2017-02-01

    Across three studies, we tested the hypothesis that women exhibit greater jealousy and mate guarding toward women who are in the high (vs. low) fertility phase of their cycle. Women who imagined their partner with a woman pictured at high fertility reported more jealousy than women who imagined their partner with a woman pictured at low fertility (Studies 1 and 2). A meta-analysis across studies manipulating fertility status of the pictured woman found a significant effect of fertility status on both jealousy and mate guarding. Women with attractive partners viewed fertile-phase women as less trustworthy, which led to increased mate guarding (Study 2). In Study 3, the closer women were to peak fertility, the more instances they reported of other women acting jealously and mate guarding toward them. These studies provide evidence that women selectively exhibit jealousy and mate guarding toward women who are near peak fertility.

  6. ModelMate - A graphical user interface for model analysis

    Science.gov (United States)

    Banta, Edward R.

    2011-01-01

    ModelMate is a graphical user interface designed to facilitate use of model-analysis programs with models. This initial version of ModelMate supports one model-analysis program, UCODE_2005, and one model software program, MODFLOW-2005. ModelMate can be used to prepare input files for UCODE_2005, run UCODE_2005, and display analysis results. A link to the GW_Chart graphing program facilitates visual interpretation of results. ModelMate includes capabilities for organizing directories used with the parallel-processing capabilities of UCODE_2005 and for maintaining files in those directories to be identical to a set of files in a master directory. ModelMate can be used on its own or in conjunction with ModelMuse, a graphical user interface for MODFLOW-2005 and PHAST.

  7. Mechanical seal having a double-tier mating ring

    Science.gov (United States)

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  8. Male Mating Signaling in Social Dilemma Games

    DEFF Research Database (Denmark)

    Jensen, Niels Holm

    2013-01-01

    According to sexual selection theory and costly signaling theory, men benefit from signaling costly mate qualities to attractive women. To date, several studies have investigated whether men use conspicuous altruism to attract women, but the findings are mixed. This study investigated whether men...... being observed by an attractive woman engage in competitive economic altruism in three social dilemma games — the Dictator Game, Trust Game (2nd mover), and Public Goods Game — in comparison to men being observed by a non-attractive woman. Results showed that altruistic contributions in the games were...... not significantly larger in the attractive observer group than in the non-attractive observer group. Exploratory analyses did reveal, however, that amongst participants with an attractive observer only, dispositional generosity had a strongly positive effect on altruism while dispositional dominance had a negative...

  9. Stochasticity in the yeast mating pathway

    International Nuclear Information System (INIS)

    Hong-Li, Wang; Zheng-Ping, Fu; Xin-Hang, Xu; Qi, Ouyang

    2009-01-01

    We report stochastic simulations of the yeast mating signal transduction pathway. The effects of intrinsic and external noise, the influence of cell-to-cell difference in the pathway capacity, and noise propagation in the pathway have been examined. The stochastic temporal behaviour of the pathway is found to be robust to the influence of inherent fluctuations, and intrinsic noise propagates in the pathway in a uniform pattern when the yeasts are treated with pheromones of different stimulus strengths and of varied fluctuations. In agreement with recent experimental findings, extrinsic noise is found to play a more prominent role than intrinsic noise in the variability of proteins. The occurrence frequency for the reactions in the pathway are also examined and a more compact network is obtained by dropping most of the reactions of least occurrence

  10. Soul mate: exploring the concept of soul.

    Science.gov (United States)

    Fenske, Joan M

    2011-09-01

    This article describes an "advanced practice" registered nurse's skill in using multiple theoretical frameworks to make meaning of her severely developmentally disabled son's untimely death. Aspects of religion, spirituality, and philosophy are presented plus how related practices, such as used within Alcoholics Anonymous, are incorporated into everyday life are referenced. Creating unique rituals and ceremonies demonstrates the power of the mind as a partner in the healing process when grief seems insurmountable. This article, titled "Soul Mate" discusses how individuals create their own healing narratives when confronted with grief and tragedy. Nursing interventions, sensitive to this process, support and promote the grief process. Eliciting, recognizing, and accepting a patient's unique self-made rituals and ceremonies as they cope with a beloved's death and dying enhances their nursing interventions. © 2011 The Author(s)

  11. Optimal mate choice patterns in pelagic copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Eliassen, Sigrun; Kiørboe, Thomas

    2013-01-01

    The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits......, and recent laboratory experiments identified some selected morphological traits. Here, we use a ‘life history-based’ model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities...... typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can...

  12. Synergistic selection between ecological niche and mate preference primes diversification.

    Science.gov (United States)

    Boughman, Janette W; Svanbäck, Richard

    2017-01-01

    The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution

  13. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    Science.gov (United States)

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  14. Nuclear power station main control room habitability

    International Nuclear Information System (INIS)

    Paschal, W.B.; Knous, W.S.

    1989-01-01

    The main control room at a nuclear power station must remain habitable during a variety of plant conditions and postulated events. The control room habitability requirement and the function of the heating, ventilating, air-conditioning, and air treatment system are to control environmental factors, such as temperature, pressure, humidity, radiation, and toxic gas. Habitability requirements provide for the safety of personnel and enable operation of equipment required to function in the main control room. Habitability as an issue has been gaining prominence with the Advisor Committee of Reactor Safeguards and the Nuclear Regulatory Commission since the incident at Three Mile Island. Their concern is the ability of the presently installed habitability systems to control the main control room environment after an accident. This paper discusses main control room HVAC systems; the concern, requirements, and results of NRC surveys and notices; and an approach to control room habitability reviews

  15. Host Star Evolution for Planet Habitability.

    Science.gov (United States)

    Gallet, Florian; Charbonnel, Corinne; Amard, Louis

    2016-11-01

    With about 2000 exoplanets discovered within a large range of different configurations of distance from the star, size, mass, and atmospheric conditions, the concept of habitability cannot rely only on the stellar effective temperature anymore. In addition to the natural evolution of habitability with the intrinsic stellar parameters, tidal, magnetic, and atmospheric interactions are believed to have strong impact on the relative position of the planets inside the so-called habitable zone. Moreover, the notion of habitability itself strongly depends on the definition we give to the term "habitable". The aim of this contribution is to provide a global and up-to-date overview of the work done during the last few years about the description and the modelling of the habitability, and to present the physical processes currently includes in this description.

  16. The cost of mating: influences of life history traits and mating strategies on lifespan in two closely related Yponomeuta species

    NARCIS (Netherlands)

    Bakker, A.C.; Campos Louçã, J.; Roessingh, P.; Menken, S.B.J.

    2011-01-01

    Theory predicts that in monandrous butterfly species males should not invest in a long lifespan because receptive females quickly disappear from the mating population. In polyandrous species, however, it pays for males to invest in longevity, which increases the number of mating opportunities and

  17. How universal are human mate choices? Size does not matter when Hadza foragers are choosing a mate

    Science.gov (United States)

    Sear, Rebecca; Marlowe, Frank W.

    2009-01-01

    It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, body mass index (BMI), per cent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or per cent fat; no evidence for a male-taller norm and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza. PMID:19570778

  18. Dynamical habitability of planetary systems.

    Science.gov (United States)

    Dvorak, Rudolf; Pilat-Lohinger, Elke; Bois, Eric; Schwarz, Richard; Funk, Barbara; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Lammer, Helmut; Léger, Alain; Liseau, René; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Frank; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    The problem of the stability of planetary systems, a question that concerns only multiplanetary systems that host at least two planets, is discussed. The problem of mean motion resonances is addressed prior to discussion of the dynamical structure of the more than 350 known planets. The difference with regard to our own Solar System with eight planets on low eccentricity is evident in that 60% of the known extrasolar planets have orbits with eccentricity e > 0.2. We theoretically highlight the studies concerning possible terrestrial planets in systems with a Jupiter-like planet. We emphasize that an orbit of a particular nature only will keep a planet within the habitable zone around a host star with respect to the semimajor axis and its eccentricity. In addition, some results are given for individual systems (e.g., Gl777A) with regard to the stability of orbits within habitable zones. We also review what is known about the orbits of planets in double-star systems around only one component (e.g., gamma Cephei) and around both stars (e.g., eclipsing binaries).

  19. Habitability from Tidally Induced Tectonics

    Science.gov (United States)

    Valencia, Diana; Tan, Vivian Yun Yan; Zajac, Zachary

    2018-04-01

    The stability of Earth’s climate on geological timescales is enabled by the carbon–silicate cycle that acts as a negative feedback mechanism stabilizing surface temperatures via the intake and outgassing of atmospheric carbon. On Earth, this thermostat is enabled by plate tectonics that sequesters outgassed CO2 back into the mantle via weathering and subduction at convergent margins. Here we propose a separate tectonic mechanism—vertical recycling—that can serve as the vehicle for CO2 outgassing and sequestration over long timescales. The mechanism requires continuous tidal heating, which makes it particularly relevant to planets in the habitable zone of M stars. Dynamical models of this vertical recycling scenario and stability analysis show that temperate climates stable over timescales of billions of years are realized for a variety of initial conditions, even as the M star dims over time. The magnitude of equilibrium surface temperatures depends on the interplay of sea weathering and outgassing, which in turn depends on planetary carbon content, so that planets with lower carbon budgets are favored for temperate conditions. The habitability of planets such as found in the Trappist-1 system may be rooted in tidally driven tectonics.

  20. TIDAL LIMITS TO PLANETARY HABITABILITY

    International Nuclear Information System (INIS)

    Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N.

    2009-01-01

    The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on Io (where tides drive volcanism that resurfaces the planet at least every 1 Myr) and produce similar surface conditions, then the development of life seems unlikely. On the other hand, if the tidal heating rate is less than the minimum to initiate plate tectonics, then CO 2 may not be recycled through subduction, leading to a runaway greenhouse that sterilizes the planet. These two cases represent potential boundaries to habitability and are presented along with the range of the traditional HZ for main-sequence, low-mass stars. We propose a revised HZ that incorporates both stellar insolation and tidal heating. We apply these criteria to GJ 581 d and find that it is in the traditional HZ, but its tidal heating alone may be insufficient for plate tectonics.

  1. ISS Habitability Data Collection and Preliminary Findings

    Science.gov (United States)

    Thaxton, Sherry (Principal Investigator); Greene, Maya; Schuh, Susan; Williams, Thomas; Archer, Ronald; Vasser, Katie

    2017-01-01

    Habitability is the relationship between an individual and their surroundings (i.e. the interplay of the person, machines, environment, and mission). The purpose of this study is to assess habitability and human factors on the ISS to better prepare for future long-duration space flights. Scheduled data collection sessions primarily require the use of iSHORT (iPad app) to capture near real-time habitability feedback and analyze vehicle layout and space utilization.

  2. Social determinants of dietary habits in Denmark

    DEFF Research Database (Denmark)

    Groth, Margit Velsing; Fagt, Sisse; Brøndsted, L.

    2001-01-01

    significantly associated with the intake of fruit and vegetables. Conclusions: Education seems to be the most important social variable to explain social differences in dietary habits. Additional variables are needed to explain dietary habits of women. Differences are seen for both foods and nutrients....... Sponsorship: The data analysis was financially supported by the Health Insurance Fund. Descriptors: socioeconomic status; education; dietary habits; diet surveys, E%; fat, fruit and vegetables....

  3. Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies.

    Science.gov (United States)

    Zamudio, K R; Sinervo, B

    2000-12-19

    Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated "sneaker" males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy.

  4. MATESOFT: a program for deducing parental genotypes and estimating mating system statistics in haplodiploid species

    DEFF Research Database (Denmark)

    Moilanen, A.; Sundström, L.; Pedersen, Jes Søe

    2004-01-01

    breeding system, mating system, parentage analysis, paternity assignment, polyandry, social insects......breeding system, mating system, parentage analysis, paternity assignment, polyandry, social insects...

  5. The habitable zone and extreme planetary orbits.

    Science.gov (United States)

    Kane, Stephen R; Gelino, Dawn M

    2012-10-01

    The habitable zone for a given star describes the range of circumstellar distances from the star within which a planet could have liquid water on its surface, which depends upon the stellar properties. Here we describe the development of the habitable zone concept, its application to our own solar system, and its subsequent application to exoplanetary systems. We further apply this to planets in extreme eccentric orbits and show how they may still retain life-bearing properties depending upon the percentage of the total orbit which is spent within the habitable zone. Key Words: Extrasolar planets-Habitable zone-Astrobiology.

  6. Carapace surface architecture facilitates camouflage of the decorator crab Tiarinia cornigera.

    Science.gov (United States)

    Sanka, Immanuel; Suyono, Eko Agus; Rivero-Müller, Adolfo; Alam, Parvez

    2016-09-01

    This paper elucidates the unique setal morphology of the decorator crab Tiarinia cornigera, and further presents evidence to that setal morphology promotes micro-organism nucleation and adhesion. The carapace of this crab is covered by clusters of setae, each comprising a hollow acicular stem that is enveloped by a haystack-like structure. Using computational fluid dynamics, we find that these setae are responsible for manipulating water flow over the carapace surface. Micro-organisms in the sea water, nest in areas of flow stagnation and as a result, nucleate to and biofoul the setae by means of chemical adhesion. Attached micro-organisms secrete extracellular polymeric substances, which we deduce must also provide an additional element of chemical adhesion to mechanically interlocked mesoscopic and macroscopic biomatter. By coupling physical and chemical methods for adhesion, T. cornigera is able to hierarchically decorate its carapace. Our paper brings to light the unique decorator crab carapace morphology of T. cornigera; and furthermore evidences its function in micro-organism nucleation and adhesion. We show how this special carapace morphology directs and guides water flow to form nesting regions of water stagnation where micro-organisms can nucleate and adhere. In the literature, decorator crab carapaces are presumed to be able to mechanically interlock biomatter as camouflage using hook-like setal outgrowths. T. cornigera contrarily exhibits clusters of hay-stack like structures. By encouraging micro-organism adhesion to the carapace setae, T. cornigera is able to effectively attach biomatter using both chemical and physical principles of adhesion. T. cornigera essentially has a super-biofouling carapace surface, for at least micro-organisms. Our work will have an impact on researchers interested in biofouling, adhesion, biomedical and purification filter systems, and in the development of novel biomimetic surfaces with tailored properties. Copyright

  7. Three-dimensional midwater camouflage from a novel two-component photonic structure in hatchetfish skin.

    Science.gov (United States)

    Rosenthal, Eric I; Holt, Amanda L; Sweeney, Alison M

    2017-05-01

    The largest habitat by volume on Earth is the oceanic midwater, which is also one of the least understood in terms of animal ecology. The organisms here exhibit a spectacular array of optical adaptations for living in a visual void that have only barely begun to be described. We describe a complex pattern of broadband scattering from the skin of Argyropelecus sp., a hatchetfish found in the mesopelagic zone of the world's oceans. Hatchetfish skin superficially resembles the unpolished side of aluminium foil, but on closer inspection contains a complex composite array of subwavelength-scale dielectric structures. The superficial layer of this array contains dielectric stacks that are rectangular in cross-section, while the deeper layer contains dielectric bundles that are elliptical in cross-section; the cells in both layers have their longest dimension running parallel to the dorsal-ventral axis of the fish. Using the finite-difference time-domain approach and photographic radiometry, we explored the structural origins of this scattering behaviour and its environmental consequences. When the fish's flank is illuminated from an arbitrary incident angle, a portion of the scattered light exits in an arc parallel to the fish's anterior-posterior axis. Simultaneously, some incident light is also scattered downwards through the complex birefringent skin structure and exits from the ventral photophores. We show that this complex scattering pattern will provide camouflage simultaneously against the horizontal radially symmetric solar radiance in this habitat, and the predatory bioluminescent searchlights that are common here. The structure also directs light incident on the flank of the fish into the downwelling, silhouette-hiding counter-illumination of the ventral photophores. © 2017 The Authors.

  8. Mate preference of female blue tits varies with experimental photoperiod.

    Directory of Open Access Journals (Sweden)

    Laura B Reparaz

    Full Text Available Organisms use environmental cues to time their life-cycles and among these cues, photoperiod is the main trigger of reproductive behaviours such as territory defence or song activity. Whether photoperiod is also important for another behaviour closely associated with reproduction, mate choice, is unknown. In many bird species, mate choice occurs at two different times during the annual cycle that strongly differ in daylength: in late winter when photoperiod is short and social mates are chosen, and again around egg-laying when photoperiod is longer and extra-pair mates are chosen. This duality makes the role that photoperiod plays on mate choice behaviours intriguing. We investigated the effect of photoperiod on mate choice using three experimental photoperiodic treatments (9 L:15 D, 14 L:10 D, 18 L:6 D, using blue tits (Cyanistes caeruleus as a biological model. We show that female choice was stronger under long photoperiods. In addition, female blue tits spent significantly more time near males with long tarsi and long wings. This latter preference was only expressed under long photoperiods, suggesting that some indices of male quality only become significant to females when they are strongly photostimulated, and therefore that females could select their social and extra-pair mates based on different phenotypic traits. These results shed light on the roles that photoperiod may play in stimulating pair-bonding and in refining female selectivity for male traits.

  9. Mating with stressed males increases the fitness of ant queens.

    Directory of Open Access Journals (Sweden)

    Alexandra Schrempf

    Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.

  10. Exoplanets Detection, Formation, Properties, Habitability

    CERN Document Server

    Mason, John W

    2008-01-01

    This edited, multi-author volume will be an invaluable introduction and reference to all key aspects in the field of exoplanet research. The reviews cover: Detection methods and properties of known exoplanets, Detection of extrasolar planets by gravitational microlensing. The formation and evolution of terrestrial planets in protoplanetary and debris disks. The brown dwarf-exoplanet connection. Formation, migration mechanisms and properties of hot Jupiters. Dynamics of multiple exoplanet systems. Doppler exoplanet surveys. Searching for exoplanets in the stellar graveyard. Formation and habitability of extra solar planets in multiple star systems. Exoplanet habitats and the possibilities for life. Moons of exoplanets: habitats for life. Contributing authors: •Rory Barnes •David P. Bennett •Jian Ge •Nader Haghighipour •Patrick Irwin •Hugh Jones •Victoria Meadows •Stanimir Metchev •I. Neill Reid •George Rieke •Caleb Scharf •Steinn Sigurdsson

  11. Disrupting the habit of interviewing

    Directory of Open Access Journals (Sweden)

    Eileen Honan

    2014-06-01

    Full Text Available This paper contributes to the growing domain of ‘post-qualitative’ research and experiments with a new (representational form to move away from traditional and clichéd descriptions of research methods. In this paper, I want to interrogate the category of interview, and the habit of interviewing, to disrupt the clichés, so as to allow thinking of different ways of writing/speaking/representing the interactions between researcher and researched that will breathe new life into qualitative inquiries. I will attempt to flatten and shred, destabilise and disrupt our common-sense ideas about interview, including those held most sacred to the qualitative community, that of anonymity and confidentiality, as well as the privilege of the ‘transcript’ in re-presenting interview data.

  12. Possible Habitability of Ocean Worlds

    Science.gov (United States)

    Noack, Lena; Höning, Dennis; Bredehöft, Jan H.; Lammer, Helmut

    2014-05-01

    In the last decade, the number of detected exoplanets has increased to over thousand confirmed planets and more as yet unconfirmed planet candidates. The scientific community mainly concentrates on terrestrial planets (up to 10 Earth masses) in the habitable zone, which describes the distance from the host star where liquid water can exist at the surface (Kasting et al., 1993). Another target group of interest are ocean worlds, where a terrestrial-like body (i.e. with an iron core and a silicate mantle) is covered by a thick water-ice layer - similar to the icy moons of our solar system but with several Earth masses (e.g. Grasset et al., 2009). When an exoplanet is detected and confirmed as a planet, typically the radius and the mass of it are known, leading to the mean density of the planet that gives hints to possible interior structures. A planet with a large relative iron core and a thick ocean on top of the silicate mantle for example would have the same average planet density as a planet with a more Earth-like appearance (where the main contributor to the mass is the silicate mantle). In this study we investigate how the radius and mass of a planet depend on the amount of water, silicates and iron present (after Wagner et al., 2011) the occurence of high-pressure-ice in the water-ice layer (note: we only consider surface temperatures at which liquid water exists at the surface) if the ocean layer influences the initiation of plate tectonics We assume that ocean worlds with a liquid ocean layer (and without the occurence of high-pressure ice anywhere in the water layer) and plate tectonics (especially the occurence of subduction zones, hydrothermal vents and continental formation) may be called habitable (Class III/IV habitats after Lammer et al., 2009). References: Kasting, J.F., Whitmire, D.P., and Reynolds, R.T. (1993). Habitable Zones around Main Sequence Stars. Icarus 101, 108-128. Grasset, O., Schneider, J., and Sotin, C. (2009). A study of the accuracy

  13. Habitability Properties of Circumbinary Planets

    Science.gov (United States)

    Shevchenko, Ivan I.

    2017-06-01

    It is shown that several habitability conditions (in fact, at least seven such conditions) appear to be fulfilled automatically by circumbinary planets of main-sequence stars (CBP-MS), whereas on Earth, these conditions are fulfilled only by chance. Therefore, it looks natural that most of the production of replicating biopolymers in the Galaxy is concentrated on particular classes of CBP-MS, and life on Earth is an outlier, in this sense. In this scenario, Lathe’s mechanism for the tidal “chain reaction” abiogenesis on Earth is favored as generic for CBP-MS, due to photo-tidal synchronization inherent to them. Problems with this scenario are discussed in detail.

  14. Plate tectonics, habitability and life

    Science.gov (United States)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    The role of plate tectonics in defining habitability of terrestrial planets is being increasingly discussed (e.g., Elkins-Tanton, 2015). Plate tectonics is a significantly evolved concept with a large variety of aspects. In the present context, cycling of material between near surface and mantle reservoirs is most important. But increased heat transport through mixing of cold lithosphere with the deep interior and formation of continental crust may also matter. An alternative mechanism of material cycling between these reservoirs is hot-spot volcanism combined with crust delamination. Hot-spot volcanism will transport volatiles to the atmosphere while delamination will mix crust, possibly altered by sedimentation and chemical reactions, with the mantle. The mechanism works as long as the stagnant lithosphere plate has not grown thicker than the crust and as long as volcanic material is added onto the crust. Thermal evolution studies suggest that the mechanism could work for the first 1-2 Ga of planetary evolution. The efficiency of the mechanism is limited by the ratio of extrusive to intrusive volcanism, which is thought to be less than 0.25. Plate tectonics would certainly have an advantage by working even for more evolved planets. A simple, most-used concept of habitability requires the thermodynamic stability of liquid water on the surface of a planet. Cycling of CO2between the atmosphere, oceans and interior through subduction and surface volcanism is an important element of the carbonate-silicate cycle, a thermostat feedback cycle that will keep the atmosphere from entering into a runaway greenhouse. Calculations for a model Earth lacking plate tectonics but degassing CO2, N, and H2O to form a surface ocean and a secondary atmosphere (Tosi et al, 2016) suggest that liquid water can be maintained on the surface for 4.5Ga. The model planet would then qualify as habitable. It is conceivable that the CO2 buffering capability of its ocean together with silicate

  15. The Feeding Habits of Mesosauridae

    Science.gov (United States)

    Silva, Rivaldo R.; Ferigolo, Jorge; Bajdek, Piotr; Piñeiro, Graciela

    2017-03-01

    Mesosauridae comprises the oldest known aquatic amniotes which lived in Gondwana during the Early Permian. Previous work in the Uruguayan mesosaur-bearing Mangrullo Formation suggested that mesosaurids lived in an inland water body, inferred as moderately hypersaline, with exceptional preservational conditions that justified describing these strata as a Fossil-Lagerstätte. Exquisitely preserved articulated mesosaur skeletons, including gastric content and associated coprolites, from the Brazilian Iratí Formation in the State of Goiás (central-western Brazil) indicate excellent conditions of preservation, extending the Konservat-Lagerstätte designation to both units in the Paraná Basin. The near-absence of more resistant fossil remains, like actinopterygian and temnospondyl bones, demonstrates the faunistic poverty of the mesosaur-bearing “salty sea”. Our studies of the alimentary habits of mesosaurids through the use of stereoscopic microscopy, light and electronic microscopy, and X-ray diffractometry suggest that the diet of mesosaurids was predominantly composed of pygocephalomorph crustaceans (possibly not exceeding 20 mm in length). However, the presence of bones and bone fragments of small mesosaurs in the gastric content, cololites, coprolites, and possible regurgitalites may also indicate cannibalistic and/or scavenging habits. Cannibalism is relatively common among vertebrates, particularly during conditions of environmental stress, like food shortage. Likewise, the apparent abundance of pygocephalomorph crustacean fossils in the Iratí and Mangrullo Formations, outside and within the studied gastric, cololite, and coprolite contents, might have to do with environmental stress possibly caused by volcanic activity, in particular ash spread into the basin during the Early Permian. In this context, casual necrophagy on the dead bodies of small mesosaurs and large pygocephalomorphs might have been an alternative alimentary behavior adopted for survival

  16. Lifetime number of mates interacts with female age to determine reproductive success in female guppies.

    Directory of Open Access Journals (Sweden)

    Jonathan P Evans

    Full Text Available In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events is often positively associated with the degree of multiple mating (actual number of males mated, most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS and survival (i.e. direct components of female fitness. Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.

  17. Interactive effects of size, contrast, intensity and configuration of background objects in evoking disruptive camouflage in cuttlefish.

    Science.gov (United States)

    Chiao, Chuan-Chin; Chubb, Charles; Hanlon, Roger T

    2007-07-01

    Disruptive body coloration is a primary camouflage tactic of cuttlefish. Because rapid changeable coloration of cephalopods is guided visually, we can present different visual backgrounds (e.g., computer-generated, two-dimensional prints) and video record the animal's response by describing and grading its body pattern. We showed previously that strength of cuttlefish disruptive patterning depends on the size, contrast, and density of discrete light elements on a homogeneous dark background. Here we report five experiments on the interactions of these and other features. Results show that Weber contrast of light background elements is--in combination with element size--a powerful determinant of disruptive response strength. Furthermore, the strength of disruptive patterning decreases with increasing mean substrate intensity (with other factors held constant). Interestingly, when element size, Weber contrast and mean substrate intensity are kept constant, strength of disruptive patterning depends on the configuration of clusters of small light elements. This study highlights the interactions of multiple features of natural microhabitats that directly influence which camouflage pattern a cuttlefish will choose.

  18. Chemical camouflage: a key process in shaping an ant-treehopper and fig-fig wasp mutualistic network.

    Science.gov (United States)

    Wang, Bo; Lu, Min; Cook, James M; Yang, Da-Rong; Dunn, Derek W; Wang, Rui-Wu

    2018-01-30

    Different types of mutualisms may interact, co-evolve and form complex networks of interdependences, but how species interact in networks of a mutualistic community and maintain its stability remains unclear. In a mutualistic network between treehoppers-weaver ants and fig-pollinating wasps, we found that the cuticular hydrocarbons of the treehoppers are more similar to the surface chemical profiles of fig inflorescence branches (FIB) than the cuticular hydrocarbons of the fig wasps. Behavioral assays showed that the cuticular hydrocarbons from both treehoppers and FIBs reduce the propensity of weaver ants to attack treehoppers even in the absence of honeydew rewards, suggesting that chemical camouflage helps enforce the mutualism between weaver ants and treehoppers. High levels of weaver ant and treehopper abundances help maintain the dominance of pollinating fig wasps in the fig wasp community and also increase fig seed production, as a result of discriminative predation and disturbance by weaver ants of ovipositing non-pollinating fig wasps (NPFWs). Ants therefore help preserve this fig-pollinating wasp mutualism from over exploitation by NPFWs. Our results imply that in this mutualistic network chemical camouflage plays a decisive role in regulating the behavior of a key species and indirectly shaping the architecture of complex arthropod-plant interactions.

  19. Inculcating reading habits among Nigerian secondary schools ...

    African Journals Online (AJOL)

    This paper looks at reading habit as process of imbibing a culture of educating, informing and enlightening people. Inculcating reading habit is very essential for the academic achievement of children and this is made possible with the help of trained and qualified teachers who help in guiding children in developing the right ...

  20. 24 CFR 203.673 - Habitability.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Habitability. 203.673 Section 203.673 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... FAMILY MORTGAGE INSURANCE Servicing Responsibilities Occupied Conveyance § 203.673 Habitability. (a) For...

  1. Bringing Exoplanet Habitability Investigations to High School

    Science.gov (United States)

    Woody, Mary Anne; Sohl, Linda

    2016-01-01

    Habitability, a.k.a. habitat suitability, is a topic typically discussed in Biology class. We present here a curriculum unit that introduces the topic of global-scale planetary habitability in a Physics classroom, allowing students to emulate the process of doing cutting-edge science and re-framing an otherwise "typical" physics unit in a more engaging and interactive way.

  2. Tides and the evolution of planetary habitability.

    Science.gov (United States)

    Barnes, Rory; Raymond, Sean N; Jackson, Brian; Greenberg, Richard

    2008-06-01

    Tides raised on a planet by the gravity of its host star can reduce the planet's orbital semi-major axis and eccentricity. This effect is only relevant for planets orbiting very close to their host stars. The habitable zones of low-mass stars are also close in, and tides can alter the orbits of planets in these locations. We calculate the tidal evolution of hypothetical terrestrial planets around low-mass stars and show that tides can evolve planets past the inner edge of the habitable zone, sometimes in less than 1 billion years. This migration requires large eccentricities (>0.5) and low-mass stars ( less or similar to 0.35 M(circle)). Such migration may have important implications for the evolution of the atmosphere, internal heating, and the Gaia hypothesis. Similarly, a planet that is detected interior to the habitable zone could have been habitable in the past. We consider the past habitability of the recently discovered, approximately 5 M(circle) planet, Gliese 581 c. We find that it could have been habitable for reasonable choices of orbital and physical properties as recently as 2 Gyr ago. However, when constraints derived from the additional companions are included, most parameter choices that indicate past habitability require the two inner planets of the system to have crossed their mutual 3:1 mean motion resonance. As this crossing would likely have resulted in resonance capture, which is not observed, we conclude that Gl 581 c was probably never habitable.

  3. Unsuccessful Study Habits in Foreign Language Courses.

    Science.gov (United States)

    Bailey, Phillip D.; Onwuegbuzie, Anthony J.

    This study determined which study habits would distinguish successful from unsuccessful foreign language learners. Participants were 219 college students from a variety of disciplinary backgrounds enrolled in either Spanish, French, German, or Japanese classes. The students completed the Study Habits Inventory and the Background Demographic Form.…

  4. SMOKING HABITS AMONG SECONDARY SCHOOL STUDENTS IN ...

    African Journals Online (AJOL)

    SMOKING HABITS AMONG SECONDARY SCHOOL STUDENTS IN SELECTED DISTRICTS IN ZIMBABWE. ... Journal of Child and Adolescent Mental Health ... Objective To examine the relationship between smoking habits and indicators of socioeconomic status, the urban/rural dimension and gender among secondary ...

  5. Genetic Influences on Adolescent Eating Habits

    Science.gov (United States)

    Beaver, Kevin M.; Flores, Tori; Boutwell, Brian B.; Gibson, Chris L.

    2012-01-01

    Behavioral genetic research shows that variation in eating habits and food consumption is due to genetic and environmental factors. The current study extends this line of research by examining the genetic contribution to adolescent eating habits. Analysis of sibling pairs drawn from the National Longitudinal Study of Adolescent Health (Add Health)…

  6. Real Business-cycle Model with Habits

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia

    2015-01-01

    This paper empirically investigates the ability of a real business-cycle model with nonseparabilities in consumption and leisure and external habits both in consumption and leisure to fit the postwar US data. The results indicate a strong but fast-dying habit in leisure, and a somewhat weaker...

  7. The Online Reading Habits of Malaysian Students

    Science.gov (United States)

    Abidin, Mohammad Jafre Bin Zainol; Pourmohammadi, Majid; Varasingam, Nalini A/P; Lean, Ooi Choon

    2014-01-01

    The purpose of this study is to ascertain the differences in online reading habits between genders and investigate the relationship between socio-economic status and online reading habits. Using a questionnaire, a quantitative approach was administered to 240 Form-Four students from four secondary schools in Penang Island, Malaysia. Findings…

  8. Cloning of the Lentinula edodes B mating-type locus and identification of the genetic structure controlling B mating.

    Science.gov (United States)

    Wu, Lin; van Peer, Arend; Song, Wenhua; Wang, Hong; Chen, Mingjie; Tan, Qi; Song, Chunyan; Zhang, Meiyan; Bao, Dapeng

    2013-12-01

    During the life cycle of heterothallic tetrapolar Agaricomycetes such as Lentinula edodes (Berk.) Pegler, the mating type system, composed of unlinked A and B loci, plays a vital role in controlling sexual development and resulting formation of the fruit body. L. edodes is produced worldwide for consumption and medicinal purposes, and understanding its sexual development is therefore of great importance. A considerable amount of mating type factors has been indicated over the past decades but few genes have actually been identified, and no complete genetic structures of L. edodes B mating-type loci are available. In this study, we cloned the matB regions from two mating compatible L. edodes strains, 939P26 and 939P42. Four pheromone receptors were identified on each new matB region, together with three and four pheromone precursor genes in the respective strains. Gene polymorphism, phylogenetic analysis and distribution of pheromone receptors and pheromone precursors clearly indicate a bipartite matB locus, each sublocus containing a pheromone receptor and one or two pheromone precursors. Detailed sequence comparisons of genetic structures between the matB regions of strains 939P42, 939P26 and a previously reported strain SUP2 further supported this model and allowed identification of the B mating type subloci borders. Mating studies confirmed the control of B mating by the identified pheromone receptors and pheromones in L. edodes. © 2013 Elsevier B.V. All rights reserved.

  9. Longevity and efficacy of bifenthrin treatment on desert-pattern U.S. military camouflage netting against mosquitoes in a hot-arid environment

    Science.gov (United States)

    Personnel deployed in support of US military operations will benefit from additions to the current Department of Defense pest management system. A recent study showed that residual insecticide treatment of woodland pattern US military camouflage netting was long lasting and effective at reducing mos...

  10. Giant Planets: Good Neighbors for Habitable Worlds?

    Science.gov (United States)

    Georgakarakos, Nikolaos; Eggl, Siegfried; Dobbs-Dixon, Ian

    2018-04-01

    The presence of giant planets influences potentially habitable worlds in numerous ways. Massive celestial neighbors can facilitate the formation of planetary cores and modify the influx of asteroids and comets toward Earth analogs later on. Furthermore, giant planets can indirectly change the climate of terrestrial worlds by gravitationally altering their orbits. Investigating 147 well-characterized exoplanetary systems known to date that host a main-sequence star and a giant planet, we show that the presence of “giant neighbors” can reduce a terrestrial planet’s chances to remain habitable, even if both planets have stable orbits. In a small fraction of systems, however, giant planets slightly increase the extent of habitable zones provided that the terrestrial world has a high climate inertia. In providing constraints on where giant planets cease to affect the habitable zone size in a detrimental fashion, we identify prime targets in the search for habitable worlds.

  11. Male aggression and mating opportunity in a poeciliid fish ...

    African Journals Online (AJOL)

    Male aggression and mating opportunity in a poeciliid fish. ... the strength of which can be assessed using repeatability of aggressive behaviour. ... A surprising finding highlighted by this study was the contradictory results for consistency in ...

  12. The role of ego-identity status in mating preferences.

    Science.gov (United States)

    Dunkel, Curtis S; Papini, Dennis R

    2005-01-01

    This study was designed to examine the role ego-identity plays in the mating preferences of late adolescents. In addition to examining the variance in mating preferences explained by ego-identity status, it was hoped that the results could assist in testing the competing Sexual Strategies (Buss & Schmitt, 1993) and Social Role (Eagly & Wood, 1999) theories. Ego-identity and the sex of the participant accounted for a significant amount of variance in the number of sexual partners desired and the penchant for short-term mating. The sex of the participant was the lone predictor of the importance placed on the mate characteristics of physical attractiveness and earning capacity with females placing more emphasis on the former and males placing more emphasis on the latter characteristic.

  13. Sexual dimorphism in stature (SDS), jealousy and mate retention.

    Science.gov (United States)

    Brewer, Gayle; Riley, Charlene

    2010-10-02

    Previous research has investigated the manner in which absolute height impacts on jealousy and mate retention. Although relative height is also important, little information exists about the potential influence of sexual dimorphism in stature (SDS) within established relationships. The current study investigated the relationship between SDS and the satisfaction, jealousy and mate retention behaviors reported by men and women. Heterosexual men (n = 98) and women (n = 102) completed a questionnaire. Men in high SDS relationships reported the lowest levels of cognitive and behavioral jealousy, although the impact of SDS on relationship satisfaction was less clear. SDS was not associated with the overall use of mate retention strategies; SDS did however affect the use of three specific strategies (vigilance, monopolization of time, love and care). SDS did not affect women's relationship satisfaction, jealousy (cognitive, behavioral, or emotional) or the use of mate retention strategies (with the exception of resource display).

  14. Sexual selection and physical attractiveness : Implications for mating dynamics.

    Science.gov (United States)

    Gangestad, S W

    1993-09-01

    Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven "good genes" sexual selection leads to predictions about the nature of trade-offs that individuals make between mates' physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women's preferences for men's qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women.

  15. Mating with large males decreases the immune defence of females ...

    Indian Academy of Sciences (India)

    1Indian Institute of Science Education and Research, BCVK Campus, ... observed results are very likely due to qualitative/quantitative differences in the .... Materials and methods .... that mated with the three types of males within each block.

  16. Social inclusion facilitates risky mating behavior in men.

    Science.gov (United States)

    Sacco, Donald F; Brown, Christina M; Young, Steven G; Bernstein, Michael J; Hugenberg, Kurt

    2011-07-01

    Although past research has reliably established unique effects of social exclusion on human cognition and behavior, the current research focuses on the unique effects of social inclusion. Recent evidence indicates that social inclusion leads to enhanced prioritization of reproductive interests. The current study extends these findings by showing that the pursuit of these inclusion-induced reproductive goals occurs in sex-specific ways. Across three experiments, social inclusion led men, but not women, to endorse riskier, more aggressive mating strategies compared to control and socially excluded participants. Specifically, included men were more likely to endorse sexual aggression (Experiment 1), high-risk mate poaching behaviors (Experiment 2), and high-risk mate retention tactics (Experiment 3). These results demonstrate that the experience of social inclusion can affect sex-differentiated preferences for risky mating strategies. © 2011 by the Society for Personality and Social Psychology, Inc

  17. Ecological mechanisms for the coevolution of mating systems and defence.

    Science.gov (United States)

    Campbell, Stuart A

    2015-02-01

    The diversity of flowering plants is evident in two seemingly unrelated aspects of life history: sexual reproduction, exemplified by the stunning variation in flower form and function, and defence, often in the form of an impressive arsenal of secondary chemistry. Researchers are beginning to appreciate that plant defence and reproduction do not evolve independently, but, instead, may have reciprocal and interactive (coevolutionary) effects on each other. Understanding the mechanisms for mating-defence interactions promises to broaden our understanding of how ecological processes can generate these two rich sources of angiosperm diversity. Here, I review current research on the role of herbivory as a driver of mating system evolution, and the role of mating systems in the evolution of defence strategies. I outline different ecological mechanisms and processes that could generate these coevolutionary patterns, and summarize theoretical and empirical support for each. I provide a conceptual framework for linking plant defence with mating system theory to better integrate these two research fields.

  18. Parent-Offspring Conflict over Short-Term Mating Strategies

    Directory of Open Access Journals (Sweden)

    Spyroulla Georgiou

    2011-12-01

    Full Text Available Individuals engage in short-term mating strategies that enable them to obtain fitness benefits from casual relationships. These benefits, however, count for less and cost more to their parents. On this basis three hypotheses are tested. First, parents and offspring are likely to disagree over short-term mating strategies, with the former considering these as less acceptable than the latter. Second, parents are more likely to disapprove of the short-term mating strategies of their daughters than of their sons. Finally, mothers and fathers are expected to agree on how much they disagree over the short-term mating strategies of their children. Evidence from a sample of 148 Greek-Cypriot families (140 mothers, 105 fathers, 119 daughters, 77 sons provides support for the first two hypotheses and partial support for the third hypothesis. The implications of these findings for understanding family dynamics are further discussed.

  19. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

    Science.gov (United States)

    Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

    2009-09-09

    Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s). We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions, suggests that the

  20. Are human mating preferences with respect to height reflected in actual pairings?

    NARCIS (Netherlands)

    Stulp, Gert; Buunk, Abraham P.; Pollet, Thomas V.; Nettle, Daniel; Verhulst, Simon

    2013-01-01

    Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the

  1. Are Human Mating Preferences with Respect to Height Reflected in Actual Pairings?

    NARCIS (Netherlands)

    Stulp, G.; Buunk, A.P.; Pollet, T.V.; Nettle, D.; Verhulst, S.

    2013-01-01

    Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the

  2. Thanatosis as an adaptive male mating strategy in the nuptial gift-giving spider Pisaura mirabilis

    DEFF Research Database (Denmark)

    Hansen, Line S.; Gonzalez, Sofía F.; Toft, Søren

    2008-01-01

    Males and females often experience different optima in mating rate, which may cause evolution of female resistance to matings and male counter adaptations to increase mating rate. Males of the spider Pisaura mirabilis display a spectacular mating behavior involving a nuptial gift and thanatosis...

  3. REINFORCEMENT OF STICKLEBACK MATE PREFERENCES: SYMPATRY BREEDS CONTEMPT.

    Science.gov (United States)

    Rundle, Howard D; Schluter, Dolph

    1998-02-01

    Detailed studies of reproductive isolation and how it varies among populations can provide valuable insight into the mechanisms of speciation. Here we investigate how the strength of premating isolation varies between sympatric and allopatric populations of threespine sticklebacks to test a prediction of the hypothesis of reinforcement: that interspecific mate discrimination should be stronger in sympatry than in allopatry. In conducting such tests, it is important to control for ecological character displacement between sympatric species because ecological character divergence may strengthen prezygotic isolation as a by-product. We control for ecological character displacement by comparing mate preferences of females from a sympatric population (benthics) with mate preferences of females from two allopatric populations that most closely resemble the sympatric benthic females in ecology and morphology. No-choice mating trials indicate that sympatric benthic females mate less readily with heterospecific (limnetic) than conspecific (benthic) males, whereas two different populations of allopatric females resembling benthics show no such discrimination. These differences demonstrate reproductive character displacement of benthic female mate choice. Previous studies have established that hybridization between sympatric species occurred in the past in the wild and that hybrid offspring have lower fitness than either parental species, thus providing conditions under which natural selection would favor individuals that do not hybridize. Results are therefore consistent with the hypothesis that female mate preferences have evolved as a response to reduced hybrid fitness (reinforcement), although direct effects of sympatry or a biased extinction process could also produce the pattern. Males of the other sympatric species (limnetics) showed a preference for smaller females, in contrast to the inferred ancestral preference for larger females, suggesting reproductive character

  4. Stress responsiveness predicts individual variation in mate selectivity.

    Science.gov (United States)

    Vitousek, Maren N; Romero, L Michael

    2013-06-15

    Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galápagos marine iguanas (Amblyrhynchus cristatus) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels - which are suppressed in female marine iguanas during reproduction - were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors

  5. Social biases determine spatiotemporal sparseness of ciliate mating heuristics.

    Science.gov (United States)

    Clark, Kevin B

    2012-01-01

    Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present

  6. Obp56h Modulates Mating Behavior in Drosophila melanogaster

    OpenAIRE

    Shorter, John R.; Dembeck, Lauren M.; Everett, Logan J.; Morozova, Tatiana V.; Arya, Gunjan H.; Turlapati, Lavanya; St. Armour, Genevieve E.; Schal, Coby; Mackay, Trudy F. C.; Anholt, Robert R. H.

    2016-01-01

    Social interactions in insects are driven by conspecific chemical signals that are detected via olfactory and gustatory neurons. Odorant binding proteins (Obps) transport volatile odorants to chemosensory receptors, but their effects on behaviors remain poorly characterized. Here, we report that RNAi knockdown of Obp56h gene expression in Drosophila melanogaster enhances mating behavior by reducing courtship latency. The change in mating behavior that results from inhibition of Obp56h express...

  7. An Automated Safe-to-Mate (ASTM) Tester

    Science.gov (United States)

    Nguyen, Phuc; Scott, Michelle; Leung, Alan; Lin, Michael; Johnson, Thomas

    2013-01-01

    Safe-to-mate testing is a common hardware safety practice where impedance measurements are made on unpowered hardware to verify isolation, continuity, or impedance between pins of an interface connector. A computer-based instrumentation solution has been developed to resolve issues. The ASTM is connected to the circuit under test, and can then quickly, safely, and reliably safe-to-mate the entire connector, or even multiple connectors, at the same time.

  8. Social structure affects mating competition in a damselfish

    Science.gov (United States)

    Wacker, Sebastian; Ness, Miriam Horstad; Östlund-Nilsson, Sara; Amundsen, Trond

    2017-12-01

    The strength of mating competition and sexual selection varies over space and time in many animals. Such variation is typically driven by ecological and demographic factors, including adult sex ratio and consequent availability of mates. The spatial scale at which demographic factors affect mating competition and sexual selection may vary but is not often investigated. Here, we analyse variation in size and sex ratio of social groups, and how group structure affects mating competition, in the site-attached damselfish Chrysiptera cyanea. Site-attached reef fishes are known to show extensive intraspecific variation in social structure. Previous work has focused on species for which the size and dynamics of social groups are constrained by habitat, whereas species with group structure unconstrained by habitat have received little attention. Chrysiptera cyanea is such a species, with individuals occurring in spatial clusters that varied widely in size and sex ratio. Typically, only one male defended a nest in multi-male groups. Nest-holding males were frequently visited by mate-searching females, with more visits in groups with more females, suggesting that courtship and mating mostly occur within groups and that male mating success depends on the number of females in the group. Male-male aggression was frequent in multi-male groups but absent in single-male groups. These findings demonstrate that groups are distinct social units. In consequence, the dynamics of mating and reproduction are mainly a result of group structure, largely unaffected short term by overall population demography which would be important in open social systems. Future studies of the C. cyanea model system should analyse longer-term dynamics, including how groups are formed, how they vary in relation to density and time of season and how social structure affects sexual selection.

  9. Social biases determine spatiotemporal sparseness of ciliate mating heuristics

    Science.gov (United States)

    2012-01-01

    Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate’s initial subjective bias, responsiveness, or preparedness, as defined by Stevens’ Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The

  10. URGENSI STRATEGI DISPOSITION HABITS OF MIND MATEMATIS

    Directory of Open Access Journals (Sweden)

    Bety Miliyawati

    2014-09-01

    Full Text Available ABSTRAK Kebiasaan berpikir (habits of mind memiliki peranan penting dalam proses pembelajaran dan perkembangan individu dalam membantu memecahkan masalah. Habits Of Mind (HOM adalah kebiasaan berpikir secara fleksibel, mengelola secara empulsif, mendengarkan dengan empati, membiasakan mengajukan pertanyaan, kebiasaan menyelesaikan masalah secara efektif, membiasakan menggunakan pengetahuan masa lalu untuk situasi baru, membiasakan berkomunikasi, berpikir jernih dengan tepat, menggunakan semua indera ketika mengumpulkan informasi, mencoba cara berbeda dan menghasilkan ide-ide yang baru, kebiasaan untuk merespon, kebiasaan untuk mengambil resiko, biasa bertanggung jawab, memiliki rasa humor, membiasakan berpikir interaktif dengan orang lain, bersikap terbuka dan mencoba terus-menerus. Hal ini sejalan dengan tujuan Kurikulum 2013, yaitu mempersiapkan generasi bangsa agar memiliki kemampuan hidup sebagai pribadi dan warga negara yang produktif, kreatif, inovatif, dan afektif. Artikel ini dikaji didasarkan atas analisis terhadap: (1 karakteristik matematika, (2 habits of mind matematis, dan (3 disposition contoh strategi HOM dalam pembelajaran matematika yang dikembangkan pada siswa. Kata Kunci    : Pembelajaran, Karakteristik Matematika, Habits of Mind Matematis   ABSTRACT Habits of mind have an important role in the learning process and the development of individuals in helping to solve the problem. Habits Of Mind (HOM is the habit of thinking flexibly, manage empulsif, listening with empathy, get used to ask questions, solve problems effectively habit, the habit of using past knowledge to new situations, to get used to communicate, think clearly, precisely, using all the senses when gathering information, trying different ways and generate new ideas, habits to respond, the habit to take risks, the usual charge, have a sense of humor, familiarize interactive thinking with others, be open and try constantly. This is in line with the curriculum

  11. Thumb Sucking: Help Your Child Break the Habit

    Science.gov (United States)

    ... older kids who continue to suck their thumbs, peer pressure at school usually ends the habit. Remember, though, ... an incredibly difficult habit to break. Remember, though, peer pressure typically leads kids to stop daytime sucking habits ...

  12. Breaking Bad Habits | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Bad Habits Breaking Bad Habits: Why It's So Hard to Change Past Issues / ... News in Health ( http://newsinhealth.nih.gov/ ) Break Bad Habits Avoid temptations. If you always stop for a ...

  13. Friendship as a Relationship Infiltration Tactic during Human Mate Poaching

    Directory of Open Access Journals (Sweden)

    Justin K. Mogilski

    2013-10-01

    Full Text Available Previous research has characterized human mate poaching as a prevalent alternative mating strategy that entails risks and costs typically not present during general romantic courtship and attraction. This study is the first to experimentally investigate friendship between a poacher and his/her target as a risk mitigation tactic. Participants (N = 382 read a vignette that differed by whether the poacher was male/female and whether the poacher and poached were friends/acquaintances. Participants assessed the likelihood of the poacher being successful and incurring costs. They also rated the poacher and poached on several personality and mate characteristics. Results revealed that friendship increased the perceived likelihood of success of a mate poaching attempt and decreased the perceived likelihood of several risks typically associated with mate poaching. However, friend-poachers were rated less favorably than acquaintance-poachers across measures of warmth, nurturance, and friendliness. These findings are interpreted using an evolutionary perspective. This study complements and builds upon previous findings and is the first experimental investigation of tactics poachers may use to mitigate risks inherent in mate poaching.

  14. Recent advances in the bioactive properties of yerba mate

    Directory of Open Access Journals (Sweden)

    Camila Helena Ferreira Cuelho

    Full Text Available Yerba mate (Ilex paraguariensis A. St. Hil. is a perennial shrub of Aquifoliaceae family that grows naturally in South America and is cultivated in Argentina, Brazil, Chile, Paraguay and Uruguay. The aim of this review is to summarize concisely recent advances published in the last 4 years on the antioxidant, anti-diabetic, anti-obesity and antimutagenic activities of yerba mate. For this, a search was made in some of the databases on the web as PubMed, Google Scholar and Medline. There are several studies in the literature reporting the effects of yerba mate in the metabolic profile related to diabetes and obesity. Among the findings of the researches are the reduction of body weight, liver triglycerides and white adipose tissue. It also increases the levels of glucagon-like peptide 1 and leptin, reduces blood glucose and insulin resistance and contributes to a lower rate of growth of adipose tissue. Regarding the antioxidant properties, chlorogenic acid, caffeic acid and rutin are the compounds that contribute to the antioxidant activity. The aqueous extract also protects the red cells of hemolysis induced by hydrogen peroxide. In mutagenesis, researches suggest that dicaffeoylquinic acids in yerba mate could be potential anti-cancer agents. Saponins in leaves of yerba mate prevent the in?ammation and colon cancer in vitro. Already in skin cancer, oral and topic treatment of rats exposed at ultraviolet radiation with mate tea prevented the lipid peroxidation and DNA damage.

  15. Mating Competitiveness of Agrotis ipsilon (Hufn.) Irradiated as Parental Pupae

    International Nuclear Information System (INIS)

    El-Naggar, S.E.M.; Ibrahim, S.M.; El-Shall, S.S.A.

    1999-01-01

    Laboratory studied were carried out to evaluate the mating competitiveness of P 1 and F 1 generations of Agrotis ipsilon when irradiated as full grown pupae with 75 and 150 Gy of gamma irradiation. The mating competitiveness values showed that either males or females of P 1 or F 1 generation were full competitive after treatment with 75 or 150 Gy at all released ratios. Mating competitiveness of both irradiated males and females was also studied to avoid problems concerning mass sexing. The results revealed that confining both sexes together gave an excellent results for population suppression in both P 1 and F 1 in both tested doses and ratios. The addition of irradiated females to the release ratio make these females encountered in mating with untreated females, and possessed 78% of all matings occurred in parent generation in the two tested doses at 5:5:1 ratio and increased to reach 88% by F 1 females 75 Gy while it was reduced to only 31% at 150 Gy, but still act in mating

  16. Mate-choice copying, social information processing, and the roles of oxytocin.

    Science.gov (United States)

    Kavaliers, Martin; Matta, Richard; Choleris, Elena

    2017-01-01

    Social and sexual behaviors, including that of mate choice, are dependent on social information. Mate choice can be modified by prior and ongoing social factors and experience. The mate choice decisions of one individual can be influenced by either the actual or potential mate choice of another female or male. Such non-independent mate choice, where individuals gain social information and socially learn about and recognizes potential mates by observing the choices of another female or male, has been termed "mate-choice copying". Here we first briefly review how, why, and under what circumstances individuals engage in mate-choice copying. Secondly, we review the neurobiological mechanisms underlying mate-choice copying. In particular, we consider the roles of the nonapeptide, oxytocin, in the processing of social information and the expression of mate-choice copying. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. HABEBEE: habitability of eyeball-exo-Earths.

    Science.gov (United States)

    Angerhausen, Daniel; Sapers, Haley; Citron, Robert; Bergantini, Alexandre; Lutz, Stefanie; Queiroz, Luciano Lopes; da Rosa Alexandre, Marcelo; Araujo, Ana Carolina Vieira

    2013-03-01

    Extrasolar Earth and super-Earth planets orbiting within the habitable zone of M dwarf host stars may play a significant role in the discovery of habitable environments beyond Earth. Spectroscopic characterization of these exoplanets with respect to habitability requires the determination of habitability parameters with respect to remote sensing. The habitable zone of dwarf stars is located in close proximity to the host star, such that exoplanets orbiting within this zone will likely be tidally locked. On terrestrial planets with an icy shell, this may produce a liquid water ocean at the substellar point, one particular "Eyeball Earth" state. In this research proposal, HABEBEE: exploring the HABitability of Eyeball-Exo-Earths, we define the parameters necessary to achieve a stable icy Eyeball Earth capable of supporting life. Astronomical and geochemical research will define parameters needed to simulate potentially habitable environments on an icy Eyeball Earth planet. Biological requirements will be based on detailed studies of microbial communities within Earth analog environments. Using the interdisciplinary results of both the physical and biological teams, we will set up a simulation chamber to expose a cold- and UV-tolerant microbial community to the theoretically derived Eyeball Earth climate states, simulating the composition, atmosphere, physical parameters, and stellar irradiation. Combining the results of both studies will enable us to derive observable parameters as well as target decision guidance and feasibility analysis for upcoming astronomical platforms.

  18. Constraining Exoplanet Habitability with HabEx

    Science.gov (United States)

    Robinson, Tyler

    2018-01-01

    The Habitable Exoplanet Imaging mission, or HabEx, is one of four flagship mission concepts currently under study for the upcoming 2020 Decadal Survey of Astronomy and Astrophysics. The broad goal of HabEx will be to image and study small, rocky planets in the Habitable Zones of nearby stars. Additionally, HabEx will pursue a range of other astrophysical investigations, including the characterization of non-habitable exoplanets and detailed observations of stars and galaxies. Critical to the capability of HabEx to understand Habitable Zone exoplanets will be its ability to search for signs of surface liquid water (i.e., habitability) and an active biosphere. Photometry and moderate resolution spectroscopy, spanning the ultraviolet through near-infrared spectral ranges, will enable constraints on key habitability-related atmospheric species and properties (e.g., surface pressure). In this poster, we will discuss approaches to detecting signs of habitability in reflected-light observations of rocky exoplanets. We will also present initial results for modeling experiments aimed at demonstrating the capabilities of HabEx to study and understand Earth-like worlds around other stars.

  19. Healthy eating habits protect against temptations.

    Science.gov (United States)

    Lin, Pei-Ying; Wood, Wendy; Monterosso, John

    2016-08-01

    Can healthy food-choice habits protect people against temptations of consuming large portion sizes and unhealthy foods? In two studies, we show that the answer is yes, good habits serve this protective role, at least in contexts in which people are not deliberating and thus fall back on habitual responses. In the first study, participants trained with unhealthy habits to approach eating chocolate, but not those trained with healthy habits, succumbed to temptation and ate more chocolates when their self-control resources were depleted. Study 2 extended and clarified these findings by demonstrating the role of environmental cues in eliciting healthy habits when self-control resources are depleted. Participants who had been trained to choose carrots habitually to a pictorial stimulus (i.e., habit cue) subsequently resisted choosing M&Ms as long as the cue was present. This effect of habit cues on healthy food choices suggests the usefulness of manipulating such cues as a means of meeting self-regulatory goals such as portion control. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Functional neuroimaging of avoidance habits in OCD

    Science.gov (United States)

    Gillan, Claire M; Apergis-Schoute, Annemieke M; Morein-Zamir, Sharon; Urcelay, Gonzalo P; Sule, Akeem; Fineberg, Naomi A; Sahakian, Barbara J; Robbins, Trevor W

    2016-01-01

    Objective The goal of this study was to determine the neural correlates of excessive habit formation in obsessive-compulsive disorder (OCD). We aimed to (i) test for neurobiological convergence with the known pathophysiology of OCD and (ii) infer, based on abnormalities in brain activation, whether these habits arise from dysfunction in the goal-directed or habit system. Method Thirty-seven OCD patients and 33 controls learned to avoid shocks while undergoing a functional Magnetic Resonance Imaging (fMRI) scan. Following 4 blocks of training, we tested if the avoidance response had become a habit by removing the threat of shock and measuring continued avoidance. We tested for task-related differences in brain activity in 3 ROIs, the caudate, putamen and medial orbitofrontal cortex at a statistical threshold of phabit formation in OCD patients, which was associated with hyper-activation in the caudate. Activation in this region was also associated with subjective ratings of increased urge to perform habits. The OCD group, as a whole, showed hyper-activation in the medial orbitofrontal cortex (mOFC) during the acquisition of avoidance, however this did not relate directly to habit formation. Conclusions OCD patients exhibited excessive habits that were associated with hyper-activation in a key region implicated in the pathophysiology of OCD, the caudate nucleus. Prior studies suggest that this region is important for goal-directed behavior, suggesting that habit-forming biases in OCD may be a result of impairments in this system, rather than differences in the build up of stimulus-response habits themselves. PMID:25526600

  1. The smell of virgins: mating status of females affects male swimming behaviour in Oithona davisae

    DEFF Research Database (Denmark)

    Heuschele, Jan; Kiørboe, Thomas

    2012-01-01

    in the presence of virgin when compared with mated females and that the cue is waterborne. The ability to distinguish between virgin and mated females may reduce male mortality during mate search and the cost related to mating behaviour (precopula) in both sexes. We estimate that at realistic population densities...... the ability of males to distinguish between virgin and mated females saves them several hours per day of dangerous and energetically expensive fast female tracking...

  2. The Habitable Zone Gallery and its Applications

    Science.gov (United States)

    Gelino, Dawn M.; Kane, S. R.

    2012-05-01

    The Habitable Zone Gallery (www.hzgallery.org) is a service to the exoplanet community which provides Habitable Zone (HZ) information for each of the exoplanetary systems with known planetary orbital parameters. The service includes a sortable table, a plot with the period and eccentricity of each of the planets with respect to their time spent in the HZ, a gallery of known systems which plot the orbits and the location of the HZ with respect to those orbits, and orbital movies. Here we discuss various educational and scientific applications of the site such as target selection, exploring planets with eccentric orbits, and investigating habitability.

  3. A Volcanic Hydrogen Habitable Zone

    International Nuclear Information System (INIS)

    Ramirez, Ramses M.; Kaltenegger, Lisa

    2017-01-01

    The classical habitable zone (HZ) is the circular region around a star in which liquid water could exist on the surface of a rocky planet. The outer edge of the traditional N_2–CO_2–H_2O HZ extends out to nearly ∼1.7 au in our solar system, beyond which condensation and scattering by CO_2 outstrips its greenhouse capacity. Here, we show that volcanic outgassing of atmospheric H_2 can extend the outer edge of the HZ to ∼2.4 au in our solar system. This wider volcanic-hydrogen HZ (N_2–CO_2–H_2O–H_2) can be sustained as long as volcanic H_2 output offsets its escape from the top of the atmosphere. We use a single-column radiative-convective climate model to compute the HZ limits of this volcanic hydrogen HZ for hydrogen concentrations between 1% and 50%, assuming diffusion-limited atmospheric escape. At a hydrogen concentration of 50%, the effective stellar flux required to support the outer edge decreases by ∼35%–60% for M–A stars. The corresponding orbital distances increase by ∼30%–60%. The inner edge of this HZ only moves out ∼0.1%–4% relative to the classical HZ because H_2 warming is reduced in dense H_2O atmospheres. The atmospheric scale heights of such volcanic H_2 atmospheres near the outer edge of the HZ also increase, facilitating remote detection of atmospheric signatures.

  4. A Volcanic Hydrogen Habitable Zone

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Ramses M.; Kaltenegger, Lisa, E-mail: rmr277@cornell.edu [Carl Sagan Institute, Cornell University, Ithaca, NY (United States)

    2017-03-01

    The classical habitable zone (HZ) is the circular region around a star in which liquid water could exist on the surface of a rocky planet. The outer edge of the traditional N{sub 2}–CO{sub 2}–H{sub 2}O HZ extends out to nearly ∼1.7 au in our solar system, beyond which condensation and scattering by CO{sub 2} outstrips its greenhouse capacity. Here, we show that volcanic outgassing of atmospheric H{sub 2} can extend the outer edge of the HZ to ∼2.4 au in our solar system. This wider volcanic-hydrogen HZ (N{sub 2}–CO{sub 2}–H{sub 2}O–H{sub 2}) can be sustained as long as volcanic H{sub 2} output offsets its escape from the top of the atmosphere. We use a single-column radiative-convective climate model to compute the HZ limits of this volcanic hydrogen HZ for hydrogen concentrations between 1% and 50%, assuming diffusion-limited atmospheric escape. At a hydrogen concentration of 50%, the effective stellar flux required to support the outer edge decreases by ∼35%–60% for M–A stars. The corresponding orbital distances increase by ∼30%–60%. The inner edge of this HZ only moves out ∼0.1%–4% relative to the classical HZ because H{sub 2} warming is reduced in dense H{sub 2}O atmospheres. The atmospheric scale heights of such volcanic H{sub 2} atmospheres near the outer edge of the HZ also increase, facilitating remote detection of atmospheric signatures.

  5. Earth's Paleomagnetosphere and Planetary Habitability

    Science.gov (United States)

    Tarduno, J. A.; Blackman, E. G.; Oda, H.; Bono, R. K.; Carroll-Nellenback, J.; Cottrell, R. D.; Nimmo, F.

    2017-12-01

    The geodynamo is thought to play an important role in protecting Earth's hydrosphere, vital for life as we know it, from loss due to the erosive potential of the solar wind. Here we consider the mechanisms and history of this shielding. A larger core dynamo magnetic field strength provides more pressure to abate the solar wind dynamic pressure, increasing the magnetopause radius. However, the larger magnetopause also implies a larger collecting area for solar wind flux during phases of magnetic reconnection. The important variable is not mass capture but energy transfer, which does not scale linearly with magnetosphere size. Moreover, the ordered field provides the magnetic topology for recapturing atmospheric components in the opposite hemisphere such that the net global loss might not be greatly affected. While a net protection role for magnetospheres is suggested, forcing by the solar wind will change with stellar age. Paleomagnetism utilizing the single silicate crystal approach, defines a relatively strong field some 3.45 billion years ago (the Paleoarchean), but with a reduced magnetopause of 5 Earth radii, implying the potential for some atmospheric loss. Terrestrial zircons from the Jack Hills (Western Australia) and other localities host magnetic inclusions, whose magnetization has now been recorded by a new generation of ultra-sensitive 3-component SQUID magnetometer (U. Rochester) and SQUID microscope (GSJ/AIST). Paleointensity data suggest the presence of a terrestrial dynamo and magnetic shielding for Eoarchean to Hadean times, at ages as old as 4.2 billion years ago. However, the magnetic data suggest that for intervals >100,000 years long, magnetopause standoff distances may have reached 3 to 4 Earth radii or less. The early inception of the geodynamo, which probably occurred shortly after the lunar-forming impact, its continuity, and an early robust hydrosphere, appear to be key ingredients for Earth's long-term habitability.

  6. Sexual conflict arising from extrapair matings in birds.

    Science.gov (United States)

    Chaine, Alexis S; Montgomerie, Robert; Lyon, Bruce E

    2015-01-20

    The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation in extrapair mating rates. Here, we invert the causal arrow and consider the consequences of extrapair matings for sexual conflict. Extrapair matings shift sexual conflict from a simple two-player (male vs. female) game to a game with three or more players, the nature of which we illustrate with simple diagrams that highlight the net costs and benefits of extrapair matings to each player. This approach helps identify the sorts of traits that might be under selection because of sexual conflict. Whether EPP is driven primarily by the extrapair male or the within-pair female profoundly influences which players are in conflict, but the overall pattern of conflict varies little among different mating systems. Different aspects of conflict are manifest at different stages of the breeding cycle and can be profitably considered as distinct episodes of selection caused by conflict. This perspective is illuminating both because conflict between specific players can change across episodes and because the traits that evolve to mediate conflict likely differ between episodes. Although EPP clearly leads to sexual conflict, we suggest that the link between sexual conflict and multiple paternity might be usefully understood by examining how deviations from lifetime sexual monogamy influence sexual conflict. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  7. Chemical and visual communication during mate searching in rock shrimp.

    Science.gov (United States)

    Díaz, Eliecer R; Thiel, Martin

    2004-06-01

    Mate searching in crustaceans depends on different communicational cues, of which chemical and visual cues are most important. Herein we examined the role of chemical and visual communication during mate searching and assessment in the rock shrimp Rhynchocinetes typus. Adult male rock shrimp experience major ontogenetic changes. The terminal molt stages (named "robustus") are dominant and capable of monopolizing females during the mating process. Previous studies had shown that most females preferably mate with robustus males, but how these dominant males and receptive females find each other is uncertain, and is the question we examined herein. In a Y-maze designed to test for the importance of waterborne chemical cues, we observed that females approached the robustus male significantly more often than the typus male. Robustus males, however, were unable to locate receptive females via chemical signals. Using an experimental set-up that allowed testing for the importance of visual cues, we demonstrated that receptive females do not use visual cues to select robustus males, but robustus males use visual cues to find receptive females. Visual cues used by the robustus males were the tumults created by agitated aggregations of subordinate typus males around the receptive females. These results indicate a strong link between sexual communication and the mating system of rock shrimp in which dominant males monopolize receptive females. We found that females and males use different (sex-specific) communicational cues during mate searching and assessment, and that the sexual communication of rock shrimp is similar to that of the American lobster, where females are first attracted to the dominant males by chemical cues emitted by these males. A brief comparison between these two species shows that female behaviors during sexual communication contribute strongly to the outcome of mate searching and assessment.

  8. Azadirachtin on Oligonychus yothersi in yerba mate Ilex paraguariensis

    Directory of Open Access Journals (Sweden)

    Luis Francisco Angeli Alves

    Full Text Available ABSTRACT: The red mite Oligonychus yothersi is one of the main pests of yerba mate in Brazil The damage this mite causes leads to leaf drop and decreased production. There are no registered acaricides for use in yerba mate; thus, laboratory and field experiments were performed to evaluate the effect of azadirachtin (Azamax(r, 250mL 100L-1 for the control of the red mite in yerba mate. In the laboratory, azadirachtin was applied to yerba mate leaf disks before (residual contact and after (direct contact infestation with 15 newly emerged red mite adult females. The effect of azadirachtin on mite behavior was evaluated in arenas with treated and untreated yerba mate leaves, and the number of mites in both areas was recorded. Ovicidal action was evaluated by applying azadirachtin to eggs and recording egg hatching. In the field, two applications of the product were performed (1L spray liquid plant-1 with a 7-day interval. The numbers of living mites were evaluated at 7, 14 and 21 days following the first application on randomly collected leaves. It was observed 86.6 and 91.4% of mortality following 24h of residual and direct contact, respectively. Repellent (62% of individuals leaving the treated area and ovicidal (98.9% decrease in egg hatching effects were also observed. The mite population in the yerba mate crop field had decreased by 59.6% at 14 days after the first application of azadirachtin. The results show the potential of azadirachtin for the control of O. yothersi in yerba mate in Brazil.

  9. Life history changes in Trogoderma variabile and T. inclusum due to mating delay with implications for mating disruption as a management tactic

    Science.gov (United States)

    Controlling postharvest pest species is a costly process with insecticide resistance and species specific control requiring multiple tactics. Mating disruption can be used to both decrease a female’s access to males and delay timing of mating and decreases overall mating success in a population and ...

  10. Optimal numbers of matings: the conditional balance between benefits and costs of mating for females of a nuptial gift-giving spider.

    Science.gov (United States)

    Toft, S; Albo, M J

    2015-02-01

    In species where females gain a nutritious nuptial gift during mating, the balance between benefits and costs of mating may depend on access to food. This means that there is not one optimal number of matings for the female but a range of optimal mating numbers. With increasing food availability, the optimal number of matings for a female should vary from the number necessary only for fertilization of her eggs to the number needed also for producing these eggs. In three experimental series, the average number of matings for females of the nuptial gift-giving spider Pisaura mirabilis before egg sac construction varied from 2 to 16 with food-limited females generally accepting more matings than well-fed females. Minimal level of optimal mating number for females at satiation feeding conditions was predicted to be 2-3; in an experimental test, the median number was 2 (range 0-4). Multiple mating gave benefits in terms of increased fecundity and increased egg hatching success up to the third mating, and it had costs in terms of reduced fecundity, reduced egg hatching success after the third mating, and lower offspring size. The level of polyandry seems to vary with the female optimum, regulated by a satiation-dependent resistance to mating, potentially leaving satiated females in lifelong virginity. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  11. Scratching the Surface of Martian Habitability

    Science.gov (United States)

    Conrad, Pamela G.

    2014-01-01

    Earth and Mars, though formed at the same time from the same materials, look very different today. Early in their histories they evolved through some of the same processes, but at some point their evolutionary paths diverged, sending them in perhaps irrevocably different directions. Knowledge of the factors that contributed to such different outcomes will help to determine how planets become habitable and how common habitable planets may be. The Mars surface environment is harsh today, but in situ measurements of ancient sedimentary rock by Mars Science Laboratory reveal chemical and mineralogical evidence of past conditions that might have been more favorable for life to exist. But chemistry is only part of what is required to make an environment habitable. Physical conditions constrain the chemical reactions that underlie life processes; the chemical and physical characteristics that make planets habitable are thus entangled.

  12. Habitability Assessment of International Space Station

    Science.gov (United States)

    Thaxton, Sherry

    2015-01-01

    The purpose of this study is to assess habitability during the International Space Station 1-year mission, and subsequent 6-month missions, in order to better prepare for future long-duration spaceflights to destinations such as Near Earth Asteroid (NEA) and Mars, which will require crewmembers to live and work in a confined spacecraft environment for over a year. Data collected using Space Habitability Observation Reporting Tool (iSHORT), crew-collected videos, questionnaires, and PI conferences will help characterize the current state of habitability for the ISS. These naturalistic techniques provide crewmembers with the opportunity to self-report habitability and human factors observations in near real-time, which is not systematically done during ISS missions at present.

  13. GIS Technology: Resource and Habitability Assessment Tool

    Data.gov (United States)

    National Aeronautics and Space Administration — We are applying Geographic Information Systems (GIS) to new orbital data sets for lunar resource assessment and the identification of past habitable environments on...

  14. Alaska Steller Sea Lion Food Habits Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains food habits samples, usually scats, collected opportunistically on Steller sea lion rookeries and haulouts in Alaska from 1985 to present....

  15. An evaluation of Skylab habitability hardware

    Science.gov (United States)

    Stokes, J.

    1974-01-01

    For effective mission performance, participants in space missions lasting 30-60 days or longer must be provided with hardware to accommodate their personal needs. Such habitability hardware was provided on Skylab. Equipment defined as habitability hardware was that equipment composing the food system, water system, sleep system, waste management system, personal hygiene system, trash management system, and entertainment equipment. Equipment not specifically defined as habitability hardware but which served that function were the Wardroom window, the exercise equipment, and the intercom system, which was occasionally used for private communications. All Skylab habitability hardware generally functioned as intended for the three missions, and most items could be considered as adequate concepts for future flights of similar duration. Specific components were criticized for their shortcomings.

  16. Human Factors and Habitability Assessment Tool

    Data.gov (United States)

    National Aeronautics and Space Administration — The major accomplishment for FY2012 was successful testing of the iPad-based Space Habitability Observation Reporting Tool (iSHORT) during NEEMO 16. iSHORT is an...

  17. Marine Mammal Food Habits Reference Collections

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory (NMML) Food Habits Reference Collection, containing over 8000 specimens of cephalopod beaks and fish bones and otoliths, is...

  18. Setting the Stage for Habitable Planets

    Directory of Open Access Journals (Sweden)

    Guillermo Gonzalez

    2014-02-01

    Full Text Available Our understanding of the processes that are relevant to the formation and maintenance of habitable planetary systems is advancing at a rapid pace, both from observation and theory. The present review focuses on recent research that bears on this topic and includes discussions of processes occurring in astrophysical, geophysical and climatic contexts, as well as the temporal evolution of planetary habitability. Special attention is given to recent observations of exoplanets and their host stars and the theories proposed to explain the observed trends. Recent theories about the early evolution of the Solar System and how they relate to its habitability are also summarized. Unresolved issues requiring additional research are pointed out, and a framework is provided for estimating the number of habitable planets in the Universe.

  19. Setting the Stage for Habitable Planets

    Science.gov (United States)

    Gonzalez, Guillermo

    2014-01-01

    Our understanding of the processes that are relevant to the formation and maintenance of habitable planetary systems is advancing at a rapid pace, both from observation and theory. The present review focuses on recent research that bears on this topic and includes discussions of processes occurring in astrophysical, geophysical and climatic contexts, as well as the temporal evolution of planetary habitability. Special attention is given to recent observations of exoplanets and their host stars and the theories proposed to explain the observed trends. Recent theories about the early evolution of the Solar System and how they relate to its habitability are also summarized. Unresolved issues requiring additional research are pointed out, and a framework is provided for estimating the number of habitable planets in the Universe. PMID:25370028

  20. The Long and the Short of Mate Attraction in a Psylloid: do Semiochemicals Mediate Mating in Aacanthocnema dobsoni Froggatt?

    Science.gov (United States)

    Lubanga, Umar K; Drijfhout, Falko P; Farnier, Kevin; Steinbauer, Martin J

    2016-02-01

    Mating is preceded by a series of interdependent events that can be broadly categorized into searching and courtship. Long-range signals convey species- and sex-specific information during searching, while short-range signals provide information specific to individuals during courtship. Studies have shown that cuticular hydrocarbons (CHCs) can be used for mate recognition in addition to protecting insects from desiccation. In Psylloidea, four species rely on semiochemicals for long-range mate attraction. Psyllid mating research has focused on long-range mate attraction and has largely ignored the potential use of cuticular hydrocarbons (CHCs) as mate recognition cues. This study investigated whether CHCs of Aacanthocnema dobsoni have semiochemical activity for long- and short-range communication prior to mating. Using a solid sampler for solvent-less injection of whole psyllids into coupled gas chromatography/mass spectrometry, we found quantitative, sex- and age-related differences in CHC profiles. Males had higher proportions of 2-MeC28, 11,15-diMeC29, and n-C33 alkanes, while females had higher proportions of 5-MeC27, 3-MeC27, 5,15-diMeC27, n-C29 and n-C30 alkanes. In males and females, 84 and 68 % of CHCs varied with age, respectively. Y-tube olfactometer bioassays provided no evidence that males or females responded to odors emanating from groups of conspecifics of the opposite sex. Tests of male and female psyllids for attraction to branchlets previously occupied by conspecifics showed no evidence of attraction to possible semiochemical residues. Our short-range chemoreception bioassay showed that males were as indifferent to freshly killed individuals of either sex with intact CHC profiles as to those treated with hexane (to remove CHCs). Aacanthocnema dobsoni utilizes substrate-borne vibrations (SBVs) for communication. Therefore, our results indicate that SBVs are probably more important than semiochemicals for long-range mate attraction. Furthermore