2,065 research outputs found
The parasitic crustaceans of fishes from the Brazilian Amazon. 10 - Acusicola pellonidis n.sp. (Copepoda: Cyclopidae) from Pellona castelnaeana (VALENCIENNES)
The female of Acusicola pellonidis n. sp. (Copepoda : Cyclopidea) is described from the gills of an Amazonian fish, Pellona castelnaeana (VALENCIENNES). The new species is distinguished from all others known for the genus by its larger size, longer antennae, sparse pigmentation and by the presence of a Y-shaped reinforcing structure in the dorsal wall of the cephalothorax. Keywords : parasitism, Crustaceans, fishes, Amazo
The parasitic crustaceans from the Brazilian Amazon. 15. Gamispatulus schizodontis gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) from the nasal fossae of Schizodon fasciatus AGASSIZ
The female of Gamispatulus schizodontis gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) is described from the nasal fossae of an Amazonian fish, Schizodon fasciatus AGASSIZ. The new genus differs from the other genera of the family by having a lateral retrostylet with a medial spatulate process, a wide flat rostral projection and a S-segmented antennule
The parasitic crustaceans of fishes from the Brazilian Amazon. 12. Ergasilus hydrolycus n.sp. (Copepoda: Poecilostomatoida) from Hydrolycus scomberoides (CUVIER)
The female of Ergasilus hydrolycus n. sp. is described from specimens taken from the gills of an Amazonian fish, Hydrolycus scomberoides (CUVIER). The new species is similar to E. bryconis THATCHER, 1981, and to E. jaraquensis THATCHER & ROBERTSON, 1982, in the form of the body, antennae and legs, and in having a curved pectinate seta on the terminal segment of the first exopod. The new species is distinguished from the other two by having a single seta representing the fifth leg, instead of two, and by having a relatively larger antennal claw. Additionally, the pigmentation of E. hydrolycus n. sp., is limited to a single transverse band at the level of the mouth while in the other two species it is diffuse and distributed throughout the body. Also, the uropod of the new species has two main setae and that of E. bryconis has three. The new species is larger than E. jaraquensis
Precision heat forming of tetrafluoroethylene tubing
An invention that provides a method of altering the size of tetrafluoroethylene tubing which is only available in limited combination of wall thicknesses and diameter are discussed. The method includes the steps of sliding the tetrafluoroethylene tubing onto an aluminum mandrel and clamping the ends of the tubing to the mandrel by means of clamps. The tetrafluorethylene tubing and mandrel are then placed in a supporting coil which with the mandrel and tetrafluorethylene tubing are then positioned in a insulated steel pipe which is normally covered with a fiber glass insulator to smooth out temperature distribution therein. The entire structure is then placed in an event which heats the tetrafluorethylene tubing which is then shrunk by the heat to the outer dimension of the aluminum mandrel. After cooling the aluminum mandrel is removed from the newly sized tetrafluorethylene tubing by a conventional chemical milling process
Birefringent Electroweak Textures
The behaviour of electromagnetic waves propagating through an electroweak
homilia string network is examined. This string network is topologically stable
as a cosmic texture, and is characterized by the spatial variation of the
isospin rotation of the Higgs field. As a consequence the photon field couples
to the intermediate vector bosons, producing a finite range electromagnetic
field. It is found that the propagation speed of the photon depends on its
polarization vector, whence an homilia string network acts as a birefringent
medium. We estimate the birefringent scale for this texture and show that it
depends on the frequency of the electromagnetic wave and the length scale of
the homilia string network.Comment: 10 page
The parasitic crustaceans of fishes from the Brazilian Amazon. 13. Gamidactylus jaraquensis gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) from the nasal fossae of Semaprochilodus insignis (SCHOMBURGK)
The female of Gamidactylus jaraquensis gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) is described from the nasal fossae of an Amazonian fish, Seniprochilodus insignis (SCHOMBURGK). The new genus differs from the two known species of Vaigamus in having a two-clawed antenna and in lacking the rostral spine
The parasitic crustaceans of fishes from the Brazilian Amazon, 14, Gamispinus diabolicus gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) from the nasal fossae of Ageneiosus brevifilis VALENCIENNES
The female of Gamispinus diabolicus gen. et sp. nov. (Copepoda: Poecilostomatoida: Vaigamidae) is described from the nasal fossae of an Amazonian fish, Ageneiosus brevifitis VALENCIENNES. The new genus differs from the other two genera of the family (Vaigamus and Gamidactylus) in having a five-segmented antennule and an antenna which terminates in one fixed and two moveable spines
A Test-Retest Transition Matrix: A Modification of McNemar’s Test
McNemar introduced what is known today as a test for symmetry in a two by two contingency tables. The logic of the test is based on a sample of matched pairs with a dichotomous response. In our example, the sample consists of the scores before and after an education program and the responses before and after the program. Each pair of scores is from only one person. The pretest divides the group of responders according to their answers to a dichotomous question. The posttest divides the two groups into two groups of like labels. The result is a two by two table. We construct a test of homogeneity, where the proportion of initially partitioned subjects will be equally distributed over the same partition after the program is completed, conditioned on the initial distribution
On Treating A Survey Of Convenience Sample As A Simple Random Sample
Threat of bias has kept many from using data gathered in less than optimal conditions. We maintain that when convenience sampling represents race and gender at nearly correct proportions and can be beneficial, as these two variables are quite often used as stratification variables. We compared a convenience sample with a proven sample. Race and Sex were nearly proportional as was found in the proven sample. We conclude that the convenience sample can be used as though it is simple random
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