Grebes are aquatic diving birds in the order Podicipediformes Grebes are distributed birds of freshwater, with some species occurring in marine habitats during migration and winter. The order contains a single family, the Podicipedidae, which includes 22 species in six extant genera. Grebes are small to medium-large in size, have lobed toes, are excellent swimmers and divers. Although they can run for a short distance, they are prone to falling over, since they have their feet placed far back on the body. Grebes have narrow wings, some species are reluctant to fly, they respond to danger by diving rather than flying, are in any case much less wary than ducks. Extant species range in size from the least grebe, at 120 grams and 23.5 cm, to the great grebe, at 1.7 kg and 71 cm. The North American and Eurasian species are all, of necessity, migratory over much or all of their ranges, those species that winter at sea are seen in flight; the small freshwater pied-billed grebe of North America has occurred as a transatlantic vagrant to Europe on more than 30 occasions.
Bills vary from short and thick to long and pointed, depending on the diet, which ranges from fish to freshwater insects and crustaceans. The feet are always large, with broad lobes on the toes and small webs connecting the front three toes; the hind toe has a small lobe. Recent experimental work has shown. Curiously, the same mechanism evolved independently in the extinct Cretaceous-age Hesperornithiformes, which are unrelated birds. Grebes have unusual plumage, it is dense and waterproof, on the underside the feathers are at right-angles to the skin, sticking straight out to begin with and curling at the tip. By pressing their feathers against the body, grebes can adjust their buoyancy, they swim low in the water with just the head and neck exposed. They swim by spreading out the feet and bring them inward with the webbing expanded to produce the forward thrust in much the same way as frogs. In the non-breeding season, grebes are plain-coloured in dark whites. However, most have ornate and distinctive breeding plumages developing chestnut markings on the head area, perform elaborate display rituals.
The young those of the genus Podiceps, are striped and retain some of their juvenile plumage after reaching full size. In the breeding season, they mate at freshwater lakes and ponds, but some species spend their non-breeding season along seacoasts; when preening, grebes eat their own feathers, feed them to their young. The function of this behaviour is uncertain but it is believed to assist with pellet formation, to reduce their vulnerability to gastric parasites. Grebes make floating nests of plant material concealed among reeds on the surface of the water; the young are precocial, able to swim from birth. The grebes are a radically distinct group of birds. Accordingly, they were at first believed to be related to the loons, which are foot-propelled diving birds, both families were once classified together under the order Colymbiformes. However, as as the 1930s, this was determined to be an example of convergent evolution by the strong selective forces encountered by unrelated birds sharing the same lifestyle at different times and in different habitat.
Grebes and loons are now separately classified orders of Podicipediformes and Gaviiformes, respectively. The cladistics vs. phenetics debate of the mid-20th century revived scientific interest in generalizing comparisons. As a consequence, the discredited grebe-loon link was discussed again; this went as far as proposing monophyly for grebes and the toothed Hesperornithiformes. In retrospect, the scientific value of the debate lies more in providing examples that a cladistic methodology is not incompatible with an overall phenetical scientific doctrine, that thus because some study "uses cladistics", it does not guarantee superior results. Molecular studies such as DNA-DNA hybridization and sequence analyses fail to resolve the relationships of grebes properly due to insufficient resolution in the former and long-branch attraction in the latter. Still – because of this – they do confirm that these birds form a ancient evolutionary lineage, they support the non-relatedness of loons and grebes.
The most comprehensive study of bird phylogenomics, published in 2014, found that grebes and flamingos are members of Columbea, a clade that includes doves and mesites. Recent molecular studies have suggested a relation with flamingos while morphological evidence strongly supports a relationship between flamingos and grebes, they hold at least eleven morphological traits in common. Many of these characteristics have been identified in flamingos, but not in grebes; the fossil Palaelodids can be considered evolutionarily, ecologically, intermediate between flamingos and grebes. For the grebe-flamingo clade, the taxon Mirandornithes has been proposed. Alternatively, they could be placed with Phoenocopteriformes taking priority; the fossil record of grebes is incomplete. The enigmatic waterbird genus Juncitarsus, however
The Alberto da Giussano class of light cruisers were a sub-class of the Condottieri class built before World War II for the Italian Regia Marina, to gain predominance in the Mediterranean Sea. They were designed by general Giuseppe Vian and were named after Condottieri of the Italian Mediaeval and Renaissance periods. Between the World Wars, the world powers started a rush to gain the supremacy on the seas. In 1926, France started to produce the Le Fantasque class of destroyers, which were superior in displacement and firepower to other destroyers of that period. To counter the French menace, the Regia Marina decided to produce a new class of cruiser that would be of intermediate size between the new French destroyer class and cruisers; the Italian ships equated to the British Leander-class cruisers. There were 4 ships, all laid down in 1928: Alberto da Giussano, Alberico da Barbiano, Bartolomeo Colleoni and Giovanni delle Bande Nere. Meant to hunt down and overwhelm the big French destroyers, the emphasis on firepower and speed resulted in these ships being unprotected against gunfire and underwater threats.
List of ships of the Second World War List of ship classes of the Second World War Media related to Di Giussano class cruiser at Wikimedia Commons
Emotional isolation is a state of isolation where one may have a well-functioning social network but still feels separated from others. Population-based research indicates that one in five middle-aged and elderly men in Sweden are isolated. Of those who do have someone in whom they can confide, eight out of ten confide only in their partner. People who have no one in whom they can confide are less to feel alert and strong, calm and happy. Instead, they are more to feel depressed, sad and worn out. Many people suffering from this kind of isolation have strong social networks, but lack a significant bond with their friends. While they can build superficial friendships, they are not able to confide in many people. People who are isolated usually feel lonely and unable to relate to others. Emotional maltreatment/abuse of children and adolescents has been in existence since antiquity, it still remains researchers' area of focus. The identification and treatment of emotional maltreatment are of ever-increasing importance to counsellors, health professionals and parents.
Empirical information has shown that emotional abuse among children, exists in developed and developing countries. In America, the rate of emotional abuse was estimated to be 103 per 1000 among 2–17 year olds. A 2 year study of United States army cases of emotional maltreatment by Jellen et al. revealed that primary emotional abuse was found in 26% of cases while emotional abuse plus physical abuse or child neglect was discovered in 14% cases. Studies on identification of emotional abuse have shown. Warner and Hansen assert that identification and reporting of maltreatment are two critical steps in improving the health status of maltreated children. Garbarino et al. in Iwaniec and Tomison and Tucci proposed five categories of emotional abuse to include rejecting. Emotional isolation can occur as a result of social isolation, or when a person lacks any close confidant or intimate partner. Though social relationships are necessary for emotional well-being, they can trigger negative feelings and thoughts and emotional isolation can act as a defense mechanism to protect a person from emotional distress.
When people are isolated, they keep their feelings to themselves, are unable to receive emotional support from others, feel "shut down" or numb, are reluctant or unwilling to communicate with others, except for the most superficial matters. Emotional isolation can occur within an intimate relationship as a result of infidelity, abuse, or other trust issues. One or both partners may feel alone within the relationship, rather than fulfilled. Identifying the source of the distress and working with a therapist to improve communication and rebuild trust can help couples re-establish their emotional bond. Cacioppo and his team has found that the brains of lonely people react differently than those with strong social networks; the University of Chicago researchers showed lonely and non-lonely subjects photographs of people in both pleasant settings and unpleasant settings. When viewing the pleasant pictures, non-lonely subjects showed much more activity in a section of the brain known as the ventral striatum than the lonely subjects.
The ventral striatum plays an important role in learning. It is part of the brain's reward center, can be stimulated by rewards like food and love; the lonely subjects displayed far less activity in this region while viewing pleasant pictures, they had less brain activity when shown the unpleasant pictures. When non-lonely subjects viewed the unpleasant pictures, they demonstrated activity in the temporoparietal junction, an area of the brain associated with empathy. Social withdrawal is avoiding people and activities one would enjoy. For some people, this can progress to a point of social isolation, where people may want to avoid contact with family and close friends most of the time, they may want to be alone because they feel it is upsetting to be with other people. Sometimes a cycle can develop where the more time they spend alone, the less they feel like people understand them; when people withdraw themselves from social interaction they tend to stay inside a set place. "Case examples of isolation" Hawthorne, G. PhD..
Perceived social isolation in a community sample: Its prevalence and correlates with aspects of peoples' lives. Social Psychiatry and Psychiatric Epidemiology, 43, 140-50. Doi:https://dx.doi.org/10.1007/s00127-007-0279-8 "What are the effects of isolation in the mind?" 6 April 2010. HowStuffWorks.com. <http://science.howstuffworks.com/life/inside-the-mind/emotions/isolation-effects.htm> 4 October 2016 DN Debatt. "Män har svårare än kvinnor att prata om sin egen död"
Tsumago-juku was the forty-second of the sixty-nine post towns on the Nakasendō. It is located in Kiso District, Nagano Prefecture, Japan, it has been restored to its appearance as an Edo-era post town and is now a popular tourist destination. During the Edo period, Tsumago was the forty-second of the sixty-nine post towns, which connected Edo with Kyoto. Prior to becoming part of the Nakasendō, it was the tenth of eleven stations along the Kisoji, a minor trade route running through the Kiso Valley; as such, it was a prosperous and cosmopolitan town, with an economy based on currency. It fell into obscurity and poverty, after the completion of the Chūō Main Line railway, which bypassed Tsumago. In 1968, local residents began an effort to restore historical structures within the town. By 1971, some 20 houses had been restored, a charter was agreed to the effect that no place in Tsumago should be "sold, hired out, or destroyed". In 1976, the town was designated by the Japanese government as a Nationally Designated Architectural Preservation Site.
Despite its historical appearance, Tsumago is inhabited, though with tourist shops as the town's main business. Tsumago contains a number of interesting properties, including: Tsumago-juku's former honjin and Okuya, the waki-honjin, are both open to visitors today; the honjin, the main inn of the post town, was destroyed, but it was rebuilt in 1995. The original building of the waki-honjin, the secondary inn, still remains and was named an Important Cultural Property in 2001; the Nagiso Museum of History contains information on the areas history, the preservation of row houses and data about row houses throughout the country. Kabuto Kannon Shrine is a small shrine dedicated to Minamoto no Yoshinaka, the "General of the Rising Sun," who built a citadel at Tsumago; the shrine was built around 1180. Tsumago Castle is nothing but a few ruins today. During the Edo period, its mountaintop location gave it wonderful views of both Tsumago-juku and Midono-juku, it served as the site of a large battle in 1584 and was dismantled in the early 17th century, as a result of the Genna era's "one country, one castle" rule.
Rurisan Kōtoku-ji Temple, with its white walls and stone base, rises one story above the area's buildings. Founded in 1500, its main deity was added in 1599, is notable for its Nightingale floors and a 500-year-old weeping cherry tree out front, its most interesting aspect, however, is the restored row of houses along the former post road. Most were houses built for common people in the mid-18th century, with shops and inns for travelers along the Nakasendō. A quiet portion of the original highway has been preserved between Tsumago and Magome, the next post town, it provides for a pleasant walk through the forests and past a waterfall. So guests do not have to walk the path twice to return to the beginning of the hike, bus service is provided between the two ends of the road. Nakasendō & Kisoji Midono-juku - Tsumago-juku - Magome-juku Tsumago sits at the south end of the Kiso District at the juncture of Routes 19 and 256, it can be reached via a nearby railway station at the town of Nagiso on the Chūō Main Line.
Groups of Traditional Buildings Map of Tsumago Aerial view
The Richmond River is a river with a mature wave dominated, barrier estuary, situated in the Northern Rivers region of New South Wales, Australia. The river rises in the Great Dividing Range, on the southern slopes of McPherson Range, west of Mount Lindesay, flows south east and north east, joined by twelve tributaries, including the Wilsons River, before reaching its mouth at its confluence with the Coral Sea of the South Pacific Ocean near Ballina. On its journey it passes through the towns of Kyogle, Casino and Woodburn. Summerland Way is situated adjacent to much of the middle reaches of the course of Richmond River. At Ballina, the Pacific Highway crosses the river; the catchment area of the river is estimated at 6,862 square kilometres, which makes it the sixth largest catchment in New South Wales. The traditional custodians of the land surrounding the Richmond River are the Aboriginal people of the Githabul, whose territory reached north to the current city of Toowoomba and included the current towns of Tenterfield and Warwick.
One of the annual rituals of the Githabul people was the movement from the mountain ranges to the coast during the winter months, when the mullet were plentiful. Omitted by Captain James Cook when he sailed up the east coast of the Australian mainland in 1770, it wasn't until Captain Henry John Rous identified the mouth of the river in 1828 that it was discovered by Europeans. Rous sailed about 20 miles up river, he subsequently named the river Richmond after the fifth Duke of Richmond. That year the explorer Allan Cunningham reached the river by land; the river was a major port from the 1840s until well into the 20th century. Soon after the first white settlers arrived they discovered the abundant supply of Australian Red Cedar in the Richmond Valley and began logging; the river was vital in the transportation of this resource. At the time of its discovery in 1828 and until the late 1890s the river had a treacherous mouth of shifting sand bars, many ships and lives were lost on it. Understandably, a decision was made to construct two breakwaters to channel the river's flow and these were completed in the early 1900s.
The construction of the breakwaters led to the formation of Shaw's Bay. In 1846, a conflict between white settlers and local Aborigines in the river valley caused the deaths of around 100 of the latter. With the decline of shipping as a transport mode, owing to better roads and rail, the closing of the North Coast Steam Navigation Company in 1954, the river became less important as a port. For boats, the river is navigable for a short way up its length as far as Casino. Wilsons River, which flows through the city of Lismore and is a major tributary of the Richmond, is navigable at least as far as Boatharbour 12 kilometres upstream from Lismore; the Richmond River is used for irrigation along its length. Several weirs have been constructed in order to mitigate the effects of flooding, most notably at Casino; the freshwater reaches of the Richmond River once supported the endemic Richmond River Cod, similar to Murray Cod and a subspecies of Eastern Freshwater Cod. This unique native fish became extinct between the 1930s and 1950s due to habitat degradation and gross overfishing, including with dynamite during the building of the local railway line.
The endangered Oxleyan Pygmy Perch has been recorded from the river. Rivers of New South Wales List of rivers of Australia Border Ranges National Park Richmond Range National Park "Richmond River catchment". Office of Environment and Heritage. Government of New South Wales. Richmond River County Council Northern Rivers Catchment Management Authority
In geometry, the snub 24-cell or snub disicositetrachoron is a convex uniform 4-polytope composed of 120 regular tetrahedral and 24 icosahedral cells. Five tetrahedra and three icosahedra meet at each vertex. In total it has 480 triangular faces, 432 edges, 96 vertices. You can make it from the 600-cell by truncating a select subset of icosahedral pyramids and converting them to icosahedrons, thereby replacing 20 tetrahedra with an isosahderon for each of 24 icosahedrons, removing 480 tetrahedra and replacing them with 24 icosahedra. You can visualize it as leaving only the base/footprint. Topologically, under its highest symmetry, as an alternation of a truncated 24-cell, it contains 24 pyritohedra, 24 regular tetrahedra, 96 triangular pyramids, it is one of three semiregular 4-polytopes made of two or more cells which are Platonic solids, discovered by Thorold Gosset in his 1900 paper. He called it a tetricosahedric for being made of icosahedron cells. Snub icositetrachoron Snub demitesseract Semi-snub polyoctahedron Sadi Tetricosahedric Thorold Gosset, 1900 The snub 24-cell is related to the truncated 24-cell by an alternation operation.
Half the vertices are deleted, the 24 truncated octahedron cells become 24 icosahedron cells, the 24 cubes become 24 tetrahedron cells, the 96 deleted vertex voids create 96 new tetrahedron cells. The snub 24-cell may be constructed by a particular diminishing of the 600-cell: by removing 24 vertices from the 600-cell corresponding to those of an inscribed 24-cell, taking the convex hull of the remaining vertices; this is equivalent to removing 24 icosahedral pyramids from the 600-cell. The vertices of a snub 24-cell centered at the origin of 4-space, with edges of length 2, are obtained by taking permutations of; these 96 vertices can be found by partitioning each of the 96 edges of a 24-cell into the golden ratio in a consistent manner, in much the same way that the 12 vertices of an icosahedron or "snub octahedron" can be produced by partitioning the 12 edges of an octahedron in the golden ratio. This is done by first placing vectors along the 24-cell's edges such that each two-dimensional face is bounded by a cycle similarly partitioning each edge into the golden ratio along the direction of its vector.
The 96 vertices of the snub 24-cell, together with the 24 vertices of a 24-cell, form the 120 vertices of the 600-cell. Each icosahedral cell is joined to 8 other icosahedral cells at 8 triangular faces in the positions corresponding to an inscribing octahedron; the remaining triangular faces are joined to tetrahedral cells, which occur in pairs that share an edge on the icosahedral cell. The tetrahedral cells may be divided into two groups, of 24 cells respectively; each tetrahedral cell in the first group is joined via its triangular faces to 3 icosahedral cells and one tetrahedral cell in the second group, while each tetrahedral cell in the second group is joined to 4 tetrahedra in the first group. The snub 24-cell has three vertex-transitive colorings based on a Wythoff construction on a Coxeter group from which it is alternated: F4 defines 24 interchangeable icosahedra, while the B4 group defines two groups of icosahedra in a 8:16 counts, the D4 group has 3 groups of icosahedra with 8:8:8 counts.
Conversely, the 600-cell may be constructed from the snub 24-cell by augmenting it with 24 icosahedral pyramids. The snub 24-cell can be obtained as a diminishing of the 600-cell at 24 of its vertices, in fact those of a vertex inscribed 24-cell. There is a further such bi-diminishing, when the vertices of a second vertex inscribed 24-cell would be diminished as well. Accordingly this one is known as the bi-24-diminished 600-cell; the snub 24-cell is called a semi-snub 24-cell because it is not a true snub. The full snub 24-cell can be constructed although it is not uniform, being composed of irregular tetrahedra on the alternated vertices; the snub 24-cell is the largest facet of the snub 24-cell honeycomb. The snub 24-cell is a part of the F4 symmetry family of uniform 4-polytopes. Snub 24-cell honeycomb T. Gosset: On the Regular and Semi-Regular Figures in Space of n Dimensions, Messenger of Mathematics, Macmillan, 1900 H. S. M. Coxeter. Regular Polytopes. New York: Dover Publications Inc. pp. 151–152, 156–157.
Snub icositetrachoron - Data and images 3. Convex uniform polychora based on the icositetrachoron - Model 31, George Olshevsky. Klitzing, Richard. "4D uniform polytopes s3s4o3o - sadi". John H. Conway, Heidi Burgiel, Chaim Goodman-Strass, The Symmetries of Things 2008, ISBN 978-1-56881-220-5 Snub 24-Cell Derived from the Coxeter-Weyl Group W, Mehmet Koca, Nazife Ozdes Koca, Muataz Al-Barwani. J. Geom. Methods Mod. Phys. 09, 1250068 Print #11: Snub icositetrachoron net, George Olshevsky