Teepees

One last trait I want you to look for in the d-stem is stubbornness. This is depicted as a d-stem that looks like a teepee or a person s legs spread wide like and upside down "v". A person who writes their d-stem like this will be very stubborn. In other words, they don t like to be confused with the facts once they ve made up their mind. They will argue a point even when they re wrong. These... 

The charmel is a tetramer in which each subunit has two a-hehcal transmembrane elements. One helix of each subunit forms the irmer coating of the pore whilst the other helices form contacts to the phosphohpid bUayer, via hydrophobic residues. Hie helices are in the form of an. .inverted teepee with the broad opening oriented to the outside, into the extracellular region (Fig. 16.6). The loops between the helix pairs are on the extracellular side and are oriented inwards to the pore. These form the selectivity filter that discriminates between K and Na The narrow selectivity filter, which is only 12 A long, joins a large hydrophobic cavity and the inner pore, which is hydrophi-lically coated. 

Fig. 26. The benzenoids (teepees) with A = Amax = 4 for h = 12, classified according to nf...

It has been shown [101] that these systems are characterized by some very restricted forms. They are called teepees (originally TP benzenoids, where T and P signify Triangulene and Phenalene, respectively). A teepee is defined as phenalene (A = 3) or triangulene (h = 6) or any number of these two units fused together so that the triangle apex of each unit points the same way (conventionally upwards). By... 

A number of different X-ray structures of bacterial potassium channels reveal the detailed atomic picture of the pore-forming part, helices S5 and S6 [9]. KcsA, which is crystallized in the closed conformation, has an overall structure similar to an inverted teepee [9a], Four identical subunits surround the ion-conducting pathway (Figure 8.2). Each subunit contains two full transmembrane helices, S5 and S6, as well as the P loop. The S6 helices line the central cavity, whereas the S5 helices are involved in interactions with the lipid environment. In the closed channel conformation the transmembrane helices meet at the cytosolic side to block the ion conduction path. In the open conformation of the channel, the S6 helix kinks at a conserved glycine residue to open the ion conduction path, as shown in the structure of the bacterial channel MthK [10], The ion conduction path is formed by the selectivity filter and the large water-filled central cavity. 

Generally 10-200 m lateral extent massive, mottled, wavy-platy, brecciated, teepee, laminar features sharp upper and diffuse lower boundaries... 

Fig. 11. (A) Type 1 tabular unit from the middle of the Unnamed Member. Note the good preservation of sedimentary structures. Units on the scale are in decimetres. (B) Type 2 tabular unit from the Piedra Parada Member. Note absence of sedimentary structures. Units on the scale are in decimetres. (C) Teepee structure from the middle of the Unnamed Member. Units on the scale are in centimetres. (D) Photomicrograph of fenestral/laminar microtextures common in tabular units with laminar, brecciated and teepee outcrop morphologies.

Irregular, unoriented and fenestral millimetresized calcite-filled fractures found in some units are interpreted as brecciation structures. Structures that resemble small folds are probably teepee structures because they are associated with rhizocretions and alveolar microtextures. There is not enough clay in these units to cause expansion, although expansive calcite growth cannot be ruled out. The laminar cemented units in the Zia Formation have abun-... 

Klappa, C.F. (1980a) Brecciation textures and teepee structures in Quaternary calcrete (caliche) profiles from eastern Spain the plant factor in their formation. Geol. J., 15(2), 81-89. 

Warren, J.K. (1982) The hydrological significance of Holocene teepees, stromatolites, and boxwork limestones in coastal salinas in south Australia. J. sediment. Geol., 52(4), 1171-1201. 

Like all other channels, bacterial channels are built of four identical subunits symmetrically arranged around a central pore (Figure 7-15). Each subunit contains two membrane-spanning a helices (S5 and S6) and a short P (pore domain) segment that partly penetrates the membrane bilayer. In the tetrameric channel, the eight transmembrane a helices (two from each subunit) form an inverted teepee, generating a water-filled cavity called the vestibule in the central portion of the channel. Four extended loops that are part of the P segments form the actual ion-selectivity filter in the narrow part of the pore near the exoplasmic surface above the vestibule. 

Grow beans on a teepee 118 Keep urban honey bees 120 Plant blueberry bushes 124 Grow an apple tree in a pot 128 Start a worm composter 130 Use eco-friendly DIY materials 136 Train a fig tree against a wall 140 Make your own barbecue 142 Plant a tree or climber for wildlife 146 Plant vegetables in a square foot garden... 

Collect use water efficiently 156 Grow pots of tomatoes 160 Garden without pesticides 162 Grow sweet peas on a teepee 168 Grow herbs for teas and infusions 172 Make your own compost 174 Grow chili peppers in a pot 176 Use reclaimed wood furniture... 

You can buy sweet peas as young plants from nurseries and farmers markets but, if you have time, you can grow your own from seed. Make sure that you choose one of the richly scented varieties—some sweet peas are bred for the shape and size of their flowers—and either sow the seeds under cover in a cold frame or greenhouse in late winter, or outdoors at the foot of the teepee poles in early- and mid-spring. 

All these old-fashioned varieties will cover a teepee, have masses of small flowers, and are richly scented ... 

Salt teepees on the Devil s Golf Course, a salina, Death Valley, California. 

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