Furrows, formation

Cytokinesis (cell division) in animal cells involves the progressive formation in telophase of a furrow between the two daughter cells in the equator of the mitotic spindle. Immunofluorescent staining of the cortical cytoplasm at the site of the contraction ring reveals an abundance of actin as well as myosin, a-actinin, and filamin (Fishkind and Wang, 1995). Cytokinesis is highly sensitive to actin-myosin inhibitors such as cytochalasin and phalloidin. 

Chemisorption of benzene at 297°C on Ni(110) occurred in a rather different manner. Several patterns, some streaked, were observed, and they followed the same sequence and showed the same behavior as those obtained when acetylene was chemisorbed on this surface (29). These structures have not been fully elucidated, but the streaked patterns suggest (i) that the mobility of adsorbed species along the "furrows of the (110) face is easier than their mobility across them, and (ii) that dissociation of the carbon skeleton of benzene and the formation of other structures occurs. 

This silyl hydrazone formation-oxidation sequence was originally developed as a practical alternative to the synthesis and oxidation of unsubstituted hydrazones by Myers and Furrow [31]. The formation of hydrazones directly from hydrazine and ketones is invariably complicated by azine formation. In contrast, silyl hydrazones can be formed cleanly from /V,/V -bis(7< rt-butyldimethylsilyl)hydrazine and aldehydes and ketones with nearly complete exclusion of azine formation. The resulting silylhydrazones undergo many of the reactions of conventional hydrazones (Wolff-Kishner reduction, oxidation to diazo intermediate, formation of geminal and vinyl iodides) with equal or greater efficiency. It is also noteworthy that application of hydrazine in this setting may also have led to cleavage of the acetate substituents. 

Apparatus Designed by Henry Cavendish and Used by Charles Hatchett for Determining the Comparative Wear of Gold When Alloyed by Varions Metals. Two frames, one above the other, each carrying twenty-eight coins, rubbed the upper coins backward and forward over the ones below. Each of the smaller concentric circles represents a coin. To avoid the formation of furrows, the direction in which the coins rubbed against each other was made to vary continually. 

Fig. 3. Schematic illustrations of distinct steps in cell division show the central role of contractile motor action in the process of mitosis. (A) to (C) replication (prophase) (D) formation of the mitotic spindle (metaphase) (E) and (F) chromosome migration (anaphase) and building of the nuclear envelopes, and (G) formation of the contractile ring containing actin and myosin, forming the cleavage furrow and eventually two separate daughter cells. CE, centriole pair A, aster of microtubules N, nucleus M, microtubules C, chromosomes K, kinetochore NR, remnant of nuclear envelope NE, nucelar envelope reforming CR, contractile ring CM, cell membrane]. From Squire (1986).

High solids (carbonates and bicarbonates) BFW will result in significant formation of carbon dioxide. The resulting carbon dioxide-laden condensate causes erosion-corrosion attack on carbon steel. Failure occurs by deep pitting, furrowing, or channeling. Corrosion inhibitors can be added to minimize this attack. 

For most cell types, mitosis typically lasts for less than Ih, and can be divided into prophase (chromosome condensation, growth of mitotic spindle and breakdown of nuclear envelope), metaphase (alignment of chromosomes along the equator of the parent cell), anaphase (separation of chromosomes) and telophase (formation of new nuclear membrane around chromosomes). Finally, furrowing and division of the cell takes place during cytokinesis to yield two distinct daughter cells. 

Sweeten, D., Parks, S.,Costa, M., and Wieschaus, E. (1991).GastrulationinDrr o/ Jit7u the formation of the ventral furrow and posterior midgut invaginations. Development 772 775-789. 

Yamamoto, M. 1964. The effect of centrifugal force on the spermatocyte of grasshopper with special reference to the structure of the spindle and the formation of the furrow. Sci. Rep. Tohoku Univ. Ser. IV, (Biol.), 30 171-178. 

Liu and co-workers [16] investigated the wear behaviour of ultra-high molecular weight polyethylene (UHMWPE) polymer. They concluded that the applied load is the main parameter and the wear resistance improvement of filler reinforced UHMWPE was attributed to the combination of hard particles, which prevent the formation of deep, wide and continuous furrows. Bijwe and co-workers [17] and Xu and Mellor [18] tested polyamide 6 (PA), polytetrafluoroethylene (PTFE) and their various composites in abrasive wear under dry and multi-pass conditions against SiC paper on a pin-on-disc tribometer. They concluded that the polymers without fillers had better abrasive wear resistance than their composites. 

A smoothing effect on the skin microrelief consequent to the use of proteins in skin care products has also been documented (26,76,81). Mechanisms invoked are the formation of a smooth colloidal film on the skin surface, water uptake and moderate swelling of the stratum corneum caused by a direct water-binding action or partial blocking of transepidermal water flow, and a stretching effect on the micro furrows of the skin surface... 

The furrowed iridium(llO) surface demonstrates similar adsorption charac-teristics with two molecular states giving rise to TPD peaks at very similar temperatures to those found for platinum (approximately 140 K and 210 K). First-order desorption kinetics give a value for the heat of desorption of around 33.6 kJ mol" with i des somewhat low at between 10 and 10 s " . A relatively low saturation coverage of 4.8 x lO molcm" was also observed on this face, in reasonable accord with the requirement for the presence of special sites. The formation of IR active states has also been observed on supported iridium and, as in the case of nickel, this was restricted to catalysts where the crystallite size was in the range 2-4 nm. 

Sanders E. 1975. Aspects of furrow membrane formation in the cleaving Drosophila embryo. Cell Tissue Res. 156 463-174. 

Turner F.R. and Mahowald A.P. 1976. Scanning electron microscopy of Drosophila embryogenesis. 1. The structure of the egg envelopes and the formation of the cellular blastoderm. Dev. Biol. 50 95-108. Zhang C.X., Lee M.P., Chen A.D., Brown S.D., and Hsieh T. 1996. Isolation and characterization of a Drosophila gene essential for early embryonic development and formation of cortical cleavage furrows. /. Cell Biol. 134 923-934. 

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