As part of a survey of Hi λ21-cm emission in the Southern Milky Way, we have detected two large shells in the interstellar neutral hydrogen near l = 279. The center velocities are +36 and +56 km s, which puts the shells at kinematic distances of 7 and 10 kpc. The larger shell is about 610 pc in diameter and very empty, with density contrast of at least 15 between the middle and the shell walls....

An extant population of the large, north-eastern New Zealand endemic landsnail Placostylus hongii is recorded here from a small islet (0.25 ha) 50 m offshore from Fanal Island in the Mokohinau group. The only previous records ofP. hongii from the Mokohinaus were of old empty shells from Fanal Island, where the species evidently became extinct at some time prior to the 1930s. The extant Mokohina...

Freshwater snails belonging to the genus Biomphalaria act as intermediate hosts for the parasite trematode Schistosoma mansoni in Africa and in the neotropical region. Identification of such molluscs is carried out based on morphological characters and the presence of cercariae is verified through squeezing snails between two glass slides or by exposing them to artificial light. However, someti...

We use a simple tight-binding model to study the magnetism of twodimensional quantum dot lattices with 1 to 12 electrons per dot. The results show that in the middle of an electron shell the lattice favours antiferromagnetism while with nearly empty or full shells ferromagnetism is favoured. The size of the antiferromagnetic region increases with the coordination number of the dot. A one-dimens...

Mean free path of inelastic electron scattering has been measured with a 200 keV transmission electron microscope for the majority of stable elemental solids and their oxides. An oscillating behavior vs atomic number Z has been revealed, such that within one row of the Periodic Table, the minimum maximum of is observed for elements with completed empty outer d shells. A significantly weaker Z d...

In earlier studies of acoustic scattering resonances and of the dispersive phase velocities of surface waves that generate them [see, e.g., Talmant et al., J. Acoust. Soc. Am. 86, 278-289 (1989) for spherical aluminum shells] we have demonstrated the effectiveness and accuracy of obtaining phase velocity dispersion curves from the known acoustic resonance frequencies. This possibility is offere...

In species with indeterminate growth, age-related size variation of reproductive competitors within each sex is often high. This selects for divergence in reproductive tactics of same-sex competitors, particularly in males. Where alternative tactics are fixed for life, the causality of tactic choice is often unclear. In the African cichlid Lamprologus callipterus, large nest males collect and p...

This paper records the invasive gastropod Melanoides tuberculata in a limnetic ecosystem located integral protection area semiarid region of state Paraíba northeast Brazil. Live individuals were collected and photographed along shallow margins Piranhas Reservoir associated with different types substrates. Photographic quadrants used to calculate number living empty shells on Individuals M. foun...

The eight flexible arms of an octopus’s body allow it to perform a wide range actions. Octopi use their several types movement, such as walking, crawling, and swimming. They different objects, empty coconut clam shells, create shelters, they have the amazing ability change skin color texture camouflage themselves in environments. Simultaneously, structure octopus creates problem for its motor c...

Abstract For solitary bees, nesting substrate availability may limit population growth. Here, we investigate the of a locally abundant bee Osmia conjuncta Cresson (Hymenoptera: Megachilidae) in empty shells exotic snails, Cepaea spp. Held (Stylommatophora: Helicidae), Hamilton, Ontario, Canada. A literature review determined that O. was sparsely distributed throughout its range, with low relati...