A Comparison of the Biology of Echinus esculentus in Different Habitats

Author(s):  
Hilary B. Moore

There are two types of ground at Port Erin, differing widely in the general environmental conditions, and each with a characteristic type of urchin on it. The difference is sufficiently well marked for the local fishermen, who collect the urchins for sale to summer visitors, to distinguish them as different types. The littoral urchins from the Breakwater are larger and thicker shelled than those from the Breast. Their gonads reach a greater maximum size, and, in fact, never fall as low even as the maximum volume for the Breast urchin gonads. This difference is probably correlated with the much greater food supply on the Breakwater, since the gonad is the one organ of the body in which the animal can store reserve food material. Spawning commences in March or April and lasts for about two months, but is slightly earlier on the Breakwater than on the Breast. Ripening also takes place considerably earlier in both sexes on the littoral ground. Spawning seems to set in at a temperature of about 7° C., and the colder winter of 1931, compared with 1932, was associated with a later ripening and spawning, i n the former year. Similarly it is suggested that the slightly later spawning on the Breast than on the Breakwater is correlated with the slightly later rise in the temperature of the water on the deeper water ground in the spring.

Aksioma ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 57-73
Author(s):  
Nurdin Nurdin ◽  
Ita Sarmita Samad ◽  
Sardia Sardia

Abstract: The theory distinguishes human based on four different personality types such as: sanguine, choleric, melancholic, and phlegmatic. Different types of personality caused by differences in the dominant fluid in the body. These differences will result in terms of behavior, ways of thinking and to get along. The type of this research that is descriptive qualitative which it is describing the logical reasoning based on Hippocrates personality types. The logical reasoning is analyzed through the four types of personality in relation to mathematical problem solving. The Analysis is done based on the logical reasoning indicator/ subindicator and the steps of problem solving stated by Polya. The result shows that there is a reasoning difference on each type of personalities. The difference can be terms of the strenght or the weakness. Sanguine is quicker in understanding problems and communicating results, choleric is more accelerated in work, melancholic is more perfect at work, and  phlegmatic is superior in terms of accuracy. Keywords: Logical reasoning, Hippocrates, sanguine, choleric, melancholic, phlegmatic


2019 ◽  
Vol 17 (1) ◽  
pp. 196-199
Author(s):  
Alice Florentin

Abstract In the preparation of”complete actors” only the technical aspects are not decisive, they will not only train them for the level of mastery. Aerobic exercises, forexample, can only play a part in recreation and muscular development, but when we talk about the scenic movement that uses actors’ preparation, the situation changes; the future actor has to work out physical exercises by passing through the mental as well as the spiritual filter. Each student should think about how the exercises indicated by the teacher feel in their bodies, the reception may be different from the way the teacher / college actors / dancers experience the movement. In this context, the student is the only expert in what he likes to do with the movements indicated by the one in front of him, or what emotions are evoked when he experiences a choreographic phrase. This makes the study of acting or dance a form of art, and the difference is given by their inner experiences. the uniqueness of the body on the move.”


2020 ◽  
Vol 12 (9) ◽  
pp. 3858 ◽  
Author(s):  
Magda Sibley ◽  
Antonio Peña-García

This paper presents the first comparative study of its type of the performance of light pipes with different types of apertures: a flat glass versus a bohemian crystal dome. Measurements were taken at 20-minute intervals over a period of one year in the bathrooms of two newly built identical houses of the same orientation located in Manchester, UK. The comparative analysis of the data collected for both light pipes types reveals that the crystal domed aperture consistently outperforms the flat glass one. Furthermore, the difference in the recorded horizontal illuminance is most marked during the winter months and at the end of the one-year experiment, indicating that the crystal dome has better performance for low incident winter light and higher resistance for the long term effect of weathering and pollution. This study provides strong evidence based on long term real measurements. Such evidence informs architects’ decisions when weighing up the aesthetic considerations of a flat glass aperture versus the higher illumination levels afforded by a crystal dome aperture with higher resistance to weathering and pollution.


2020 ◽  
Vol 12 (10) ◽  
pp. 4232
Author(s):  
Khaled Shaaban ◽  
Hassan Hamad

A critical gap value of a roundabout is mainly affected by the interactions between the circulating vehicles and vehicles entering the roundabout. These interactions are impacted by many factors, including the number of circulating lanes, the aggressiveness of local drivers, vehicle types, and the number of approaching lanes. Therefore, it is essential to locally investigate critical gap values before conducting any studies to improve capacity and delay at roundabouts. The purpose of this study is to measure and compare the critical gap values for different types of roundabouts in Qatar. More than 10,000 measurements were collected. The results showed that the critical gap values were 2.24 s, 2.55 s, and 2.40 s for the one-, two-, and three-lane roundabouts, respectively. These values are also quite low when compared to values calculated in other countries, which can be an indication of driver aggressiveness and risky behavior. The study is one of the first efforts to compare three types of roundabouts and to understand the difference in operation between them in this region. The results of this study can help engineers, planners, and public agencies to plan, study, and design similar facilities.


2014 ◽  
Vol 8 (2) ◽  
Author(s):  
Simone Elisabeth Lang

AbstractIn describing the position of the narrator, research in literary studies generally follows Gérard Genette’s pioneering theory of narrative in distinguishing between the homo- and heterodiegetic type of narrator. This categorization is not sufficient to allow the position of the narrator to be described properly. The different ways in which the terms are used in literary studies reveal a shortcoming in the distinction behind them. Even in Genette’s work, there is a contradiction between the definition and the names of the two categories: Genette defines homo- and heterodiegesis with reference to the narrator’s presence in the narrated story, whereas he elsewhere states that the diegesis (in the sense of FrenchThe present article aims to do just that, starting from a theoretical standpoint. Thus, the different types of narrator that are possible are sketched in outline, and then explained with the help of examples.I begin by exposing the problems that result from using the terms in Genette’s manner (1), in order then to develop a list of possible narratorial standpoints based on the one hand on the involvement of the narratorial instance in the narrated world and on the other on its involvement in the story. By establishing separation of the two aspects as a ground rule in this way, a number of misunderstandings that are due to the varied ways in which the terminology has been used to date can be overcome.There follows a description of those cases that are unambiguously hetero- and homodiegetic (2), after which the problematic cases are considered (3), yielding the different types of homodiegetic narration that are possible. This latter set of distinctions will, like the others, shed light on the contours of the different narratorial positions and thus be capable of being put profitably into practice in textual interpretation. Accordingly, what is suggested is a way of using the terms that is first unambiguous and second beneficial to the interpretation of works, thus doing justice to the heuristic importance of narratology (see Kindt/Müller 2003; Stanzel 2002, 19).Thus, whereas the concept of diegesis provides the foundation for a distinction based on an ontological criterion that divides homo- and heterodiegesis from each other, the relationship between story and narrator is used to describe various types of homodiegetic narration. In the process, there come to light two types that are distinguished from each other by involvement in events (›homodiegetic, in the story‹ and ›homodiegetic, not in the story‹ narrators). If the narrator is not involved in events, the question arises of whether it would in principle have been possible for him to be involved in events, which is the norm with ›homodiegetic, not in the story‹ narrators, or whether a physical impossibility is the reason for his lack of involvement in the story. A special case of the ›homodiegetic, not in the story‹ narrator can be derived from this: peridiegetic narration: whereas narratorial instances of the ›homodiegetic, in the story‹ and ›homodiegetic, not in the story‹ types could in principle have been involved in the action and those of the ›homodiegetic, in the story‹ type actually were, peridiegetic narrators are marked by the fact that they cannot have been involved in the events.In summary, it will be shown that the concept of homodiegesis – in particular in the form in which it has previously been used, where links with the action and appearance in the story were not kept distinct – is in effect an umbrella term that brings together a number of possible forms. There is a prominent distinction between the ›homodiegetic, in the story‹ and the ›homodiegetic, not in the story‹ types of narrator (these types are represented in the present article by the old lawyer in Leo Perutz’s »The Beaming Moon« and the narrator who is a friend of Nathanael in E. T. A. Hoffmann’s »Sandman« respectively). The different degrees of homodiegetic narrator, which have often been mentioned in previous research and are defined by the strength of the character’s presence in the narrated world (from an uninvolved witness to an autodiegetic protagonist), are also to be situated between these two poles.It will also be shown in the process that the case of the narrator who is, for reasons of physical difference, not involved in events (the peridiegetic narrator) should be treated as a form of homodiegesis (for instance the schoolmaster in Theodor Storm’s


1917 ◽  
Vol 25 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Tokuzo Ohira ◽  
Hideyo Noguchi

Trichomonades from the mouth were studied by Steinberg who proposed to group them into three distinct types; namely, Trichomonas elongata, Trichomonas caudata, and Trichomonas flagellata. Doflein (3) regards them as probably identical with Trichomonas hominis. Opinions differ as to whether or not Trichomonas vaginalis Donné and Trichomonas hominis Grassi are the same species. Lynch, for instance, believes that they are the same species, while von Prowazek (4), Bensen (5), and others (6, 7) insist that they are different types. Bensen's view seems to be well supported by the difference alleged to be found between the mode of encystment in the two trichomonades, were it not for the fact that our knowledge about the so called cyst of trichomonades is still obscure. According to Alexeieff (8) many of the so called cysts were evidently blastomyces contained in the cell body of the trichomonas. An autogamy alleged to take place in cysts as described by Bohne and von Prowazek (9) has not been confirmed by Dobell (10). And Wenyon (11) contends that it has never been found possible to produce any development of these cysts outside the body on the warm stage as can be done with the cysts of Entamœba coli. Therefore, it is still premature to take the process of encystment into consideration as far as the classification of trichomonas is concerned. On the other hand, Rodenwaldt (12) seems to think that there are many species of trichomonas in the human intestines, and Wenyon has described a new trichomonas from the human intestines (Macrostoma mesnili Wenyon). Further cultural studies in the morphology and biology of these organisms must be carried out in order to solve these problems. In the light of modern investigations there are five subgenera to be included under the genus Trichomonas Donné. They are as follows: (1) Protrichomonas Alexeieff, with three anterior flagella, without an undulating membrane. (2) Trichomastix Biitschli) with three anterior flagella and a trailing flagellum (Schleppgeissel) without an undulating membrane. (3) Trichomonas Donné, with three anterior flagella and an undulating membrane. (4) Macrostoma Alexeieff, Amend, Wenyon (11), with three anterior flagella and an undulating membrane wedged in a deep groove (peristome). (5) Tetratrichomonas Parisi (13), with four anterior flagella and an undulating membrane. As far as our culture trichomonas from the human mouth is concerned, it has been shown that it is not strictly a trichomonas and that it should be classed under the subgenus Tetratrichomonas.


1927 ◽  
Vol 46 ◽  
pp. 334-348 ◽  
Author(s):  
John Tait

Summary1. Following upon a previous study of spirit specimens of Glyptonotus, observations have been made on live examples of Chiridotea cœca and C. tuftsii with the object of elucidating points relating to the natural history and structural peculiarities of the Glyptonoteinæ.2. Though wholly carnivorous, Chiridotea is not a predaceous animal. Subsisting on portions of animals, already dead, which it discovers by persevering search aided by sense of smell, it is a scavenger rather than a hunter of living prey.3. The uncommon division of the thoracic limbs in Chiridotea is associated with an exceptional range of locomotor accomplishments. The animal not only walks and swims like other members of the Idoteidæ, but also tunnels its way for long distances under the surface of sand.4. The three pairs of gnathopods subserve a number of functions. They are used in ordinary reptant progression. They are used to seize and hold on to food, but not to tear or rend it. Working in conjunction with the mandibles, they play an essential part in the process of manducation. They also come into action during sand-tunnelling.5. On closer observation the characteristic type of limb-taxis of Chiridotea proves to be specially related to the tunnelling habit. During the process of tunnelling the mesially situated gnathopods and pleopods, working together, deal with one body of sand, the laterally projecting peræopods with another.6. Certain common features in the bodily conformation of Serolis, of Apus, of Limulus, and of Trilobites are interpreted as an adaptation, by convergence, to a habitat on the surface of mud.7. Owing to the transparency of its body, the movements of the alimentary canal of Chiridotea can be observed during ingestion and the movements of the hepatic cæca during digestion of food.8. The midgut exhibits, according to circumstances, two different types of peristaltic movement. At the very commencement of a meal, and also during long continued vain effort to masticate a tough morsel of food, a succession of forward-running waves of contraction is observed. When food begins to be swallowed these are replaced by backward-coursing waves of contraction.9. There are two pairs of hepatic cæca. As the midgut fills the more mesial pair passes out of sight. The laterally situated cæca increase greatly in volume and exhibit a series of dilatations or pockets, which enter into vigorous and long-sustained rhythmic contraction.10. The mesial split in the thoracic sternites is a device for allowing distension of the body after a meal.11. Its eyes being wholly dorsal, Chiridotea shows no conspicuous colour change in response to its background. It has both brown and black chromatophores, the latter contractile.12. A new point of specific difference between C. cœca and C. tuftsii is recorded.13. The direction of rotation by which the uropods of Valvifera have assumed their present orientation is discussed anew, the conclusion again being that the anterior border was originally mesial.14. Objections are raised against the elevation by Racovitza and Sevastos of the northern representatives of Miers' Glyptonoteinæ to independent sub-family rank.


1997 ◽  
Vol 47 (2) ◽  
pp. 525-542 ◽  
Author(s):  
P. N. Singe

Galen's æuvre presents a remarkably varied body of texts–varied in subject matter, style, and didactic purpose. Logical tracts sit alongside tomes of drug–lore; handbooks of dietetics alongside anatomical investigations; treatises of physiology alongside ethical opuscula. These differences in type have received some, though as yet insufficient, scholarly attention. Mario Vegetti demonstrated the coexistence of two ‘profili’ or images of the art of medicine: Galen presents the art as an Aristotelian deductive science, on the one hand, and as a technician's craft, on the other. The former image, offering an ambitious elevation of the doctor's cultural status, has medicine as a philosophical episteme analogous to the mathematical sciences, exercised above all to provide causal accounts and logical demonstrations, and centred on the knowledge of anatomy. The second image is that of the clinician, concerned with the body in its pathological manifestations and using as its prime model the ‘pre-anatomical’ theory of the humours. And the content of the treatises shifts in relation to this dual image: ‘profilo alto’ and ‘profilo basso’ are reflected in different types of work. Polemical writings such as the Protrepticus, as well as the great treatises of anatomy and physiology, De usu partium and De naturalibus facultatibus, present medicine in the former light, while works like De temperamentis or Quod animi mores base themselves on humoral pathology and accord with the earlier, artisan-like image.


Author(s):  
Kurt Öberg ◽  
Anna Torén ◽  
Malin Hansson

Tractor drivers have quite often musculoskeletal problems because of bad sitting postures. It has been found that a good sitting posture is the one obtained when sitting on a horse with the hips in a muscle balanced rest position of 45°. A natural curvature of the spine is acquired as well as a perfectly balanced position in which the body obtains a good position of the centre of gravity. To improve the sitting posture of the driver of agricultural tractors, different types of saddle seats were adapted to fit in a tractor, and tested upon their comfort, work function and sitting posture. The saddle seats occupied less space in the horizontal plane compared to the conventional chair, and they were rotating freely during driving. Ten subjects employed as tractor drivers volunteered for the study. They harrowed and ploughed with three different saddle seats and one conventional tractor chair. Questions on experienced chair comfort and work function were asked. The drivers were video filmed from above and from the side in order to register their sitting posture. On a scale from 1 to 5 the conventional chair received a mean score of 3.6 and the saddle seats received mean score around 2. The difference is regarded to depend on differences in seat comfort. The saddle seats free rotation was mainly used during ploughing and reduced the spinal twisting 50%. The seat height adjusted by the tractor drivers was for the saddle seats 13 cm higher than for the conventional chair. This meant that the drivers received a sitting posture advantageous for the spine curvature. A future design of a tractor chair should have the possibility of varying raised sitting posture and free rotation. The seat should have a shape which gives a better seat comfort than any of the tested saddle seats.


2014 ◽  
Vol 600 ◽  
pp. 57-68 ◽  
Author(s):  
Patricia Luna ◽  
Caori Takeuchi ◽  
Edwar Cordón

This paper presents the mechanical properties measured on glued laminated pressed guadua samples. Experimental tests like shear parallel to fiber, tensile and shear perpendicular to fiber and flexural tests were carried out using three different types of adhesives: European Melamine Urea Formaldehyde, Colombian Melamine Urea Formaldehyde, and Polivinil Acetate humidity resistant. In order to study the behavior of the material in aggressive environmental conditions, half of the samples used in the mechanical tests were introduced in a temperature and humidity chamber for 45 days set to 45°C of temperature and 95% of relative humidity, usual environmental conditions in Chocó Colombia.The results showed that the highest values of mechanical strength were obtained for samples made with European Melamine Urea Formaldehyde. In addition, it was found that this adhesive was the one with better behavior under the aggressive environmental conditions simulated.


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