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Company acquisition and mergers can result in a reduction in employee morale because of redundancies, cost-cutting, the lack of communication and changes. The study examines 3 companies involved in different types of acquisition and mergers and the effect on the employees. Middle managers, supervisors and administrators were interviewed. The survey shows the importance of: communication prior, during and after the merger; the development of a strategic plan involving all employees; flexibility with job changes and retraining programmes.

Summary Diffusion of inorganic mercury (Hg2+) through planar lipid bilayer membranes was studied as a function of chloride concentration and pH. Membranes were made from egg lecithin plus cholesterol in tetradecane. Tracer (203Hg) flux and conductance measurements were used to estimate the permeabilities to ionic and nonionic forms of Hg. At pH 7.0 and [Cl-] ranging from 10–1000mm, only the dichloride complex of mercury (HgCl2) crosses the membrane at a significant rate. However, several other Hg complexes (HgOHCl, HgCl3- and HgCl42-) contribute to diffusion through the aqueous unstirred layer adjacent to the membrane. The relation between the total mercury flux (JHg), Hg concentrations, and permeabilities is: 1/JHg=1/Pul[Hgt]+1/Pm[HgCl2], where [Hgt] is the total concentration of all forms of Hg,Pul is the unstirred layer permeability, andPm is the membrane permeability to HgCl2. By fitting this equation to the data we find thatPm=1.3×10-2 cm sec-1. At Cl- concentrations ranging from 1–100mm, diffusion of Hgt through the unstirred layer is rate limiting. At Cl- concentrations ranging from 500–1000mm, the membrane permeability to HgCl2 becomes rate limiting because HgCl2 comprises only about 1% of the total Hg. Under all conditions, chemical reactions among Hg2+, Cl- and/or OH- near the membrane surface play an important role in the transport process. Other important metals, e.g., Zn2+, Cd2+, Ag+ and CH3Hg+, form neutral chloride complexes under physiological conditions. Thus, it is likely that chloride can “facilitate” the diffusion of a variety of metals through lipid bilayer and biological membranes.

Summary The current-voltage (I–V) relationships for internally perfused and nonperfused cells ofHalicystis parvula were determined. In both types of cells theI–V curve shows a conspicuous region of negative slope, beginning at vacuole potentials around -30 mV and continuing to values of +20 to +40mV. The negative slope in perfused cells is abolished by the metabolic inhibitors, darkness and low temperature. In order to determine the origin of this negative slope, we measured the voltage sensitivity of the unidirectional fluxes of Cl-, Na+ and K+ in perfused cells. The results show that the Cl- influx, which is mediated primarily by a Cl- pump, increases as the vacuole potential is clamped at increasingly morenegative values up to -50 mV, while the other fluxes measured changed in the directions predicted by the change in electrical driving force. The voltage sensitivity of the Cl- pump quantitatively accounts for the negative slope of theI–V curve. Also, we observed a large transient outward current of 10–20-sec duration following an abrupt depolarization by voltage clamping. This transient current was reduced or abolished by low temperature, which suggests that it may be due to the voltage-sensitive Cl- pump. Finally, we found an inverse relationship between the transprotoplasm resistance (Rm) and thePD under standard conditions, which suggests that the activity of the electrogenic Cl- pump lowerRm, i.e., it is a conductive pump.

Thin lipid (optically black) membranes were made from sheep red cell lipids dissolved in n-decane. The flux of Br across these membranes was measured by the use of tracer 82Br. The unidirectional flux of Br (in 50–100 mM NaBr) was 1–3 x 10-12 mole/cm2sec. This flux is more than 1000 times the flux predicted from the membrane electrical resistance (>108 ohm-cm2) and the transference number for Br- (0.2–0.3), which was estimated from measurements of the zero current potential difference. The Br flux was not affected by changes in the potential difference imposed across the membrane (±60 mv) or by the ionic strength of the bathing solutions. However, the addition of a reducing agent, sodium thiosulfate (10-3 M), to the NaBr solution bathing the membrane caused a 90% reduction in the Br flux. The inhibiting effect of S2O3= suggests that the Br flux is due chiefly to traces of Br2 in NaBr solutions. As expected, the addition of Br2 to the NaBr solutions greatly stimulated the Br flux. However, at constant Br2 concentration, the Br flux was also stimulated by increasing the Br- concentration, in spite of the fact that the membrane was virtually impermeable to Br-. Finally, the Br flux appeared to saturate at high Br2 concentrations, and the saturation value was roughly proportional to the Br- concentration. These results can be explained by a model which assumes that Br crosses the membrane only as Br2 but that rapid equilibration of Br between Br2 and Br- occurs in the unstirred layers of aqueous solution bathing the two sides of the membrane. A consequence of the model is that Br- "facilitates" the diffusion of Br across the unstirred layers.

Ultrathin (black) lipid membranes were made from sheep red cell lipids dissolved in n-decane. The presence of aliphatic alcohols in the aqueous solutions bathing these membranes produced reversible changes in the ionic permeability, but not the osomotic permeability. Heptanol (8 mM), for example, caused the membrane resistance (Rm) to decrease from >108 to about 105 ohm-cm2 and caused a marked increase in the permeability to cations, especially potassium. In terms of ionic transference numbers, deduced from measurements of the membrane potential at zero current, Tcat/TCl increased from about 6 to 21 and TK/TNa increased from about 3 to 21. The addition of long-chain (C8ndash;C10) alcohols to the lipid solutions from which membranes were made produced similar effects on the ionic permeability. A plot of log Rm vs. log alcohol concentration was linear over the range of maximum change in Rm, and the slope was -3 to -5 for C2 through C7 alcohols, suggesting that a complex of several alcohol molecules is responsible for the increase in ionic permeability. Membrane permselectivity changed from cationic to anionic when thorium or ferric iron (10-4 M) was present in the aqueous phase or when a secondary amine (Amberlite LA-2) was added to the lipid solutions from which membranes were made. When membranes containing the secondary amine were exposed to heptanol, Rm became very low (103–104 ohm-cm2) and the membranes became perfectly anion-selective, developing chloride diffusion potentials up to 150 mv.

Ion transport in the giant celled marine alga, Valonia ventricosa, was studied during internal perfusion and short-circuiting of the vacuole potential. The perfusing and bathing solutions were similar to natural Valonia sap and contained the following concentrations of major ions: Na 51, K 618, and Cl 652 mM. The average short-circuit current (Isc) was 97 pEq/cm2 sec (inward positive current), and the average open-circuit potential difference (PD) was 74 mv (vacuole positive to external solution). Perfused and short-circuited cells showed a small net influx of Na (2.0 pEq/cm2 sec) and large net influxes of K (80 pEq/cm2 sec) and Cl (50 pEq/cm2 sec). Unidirectional K influx was proportional to Isc, but more than one-half of the Isc remained unaccounted for. Both the Isc and PD were partly light-dependent, declining rapidly during the first 1–2 min of darkness. Ouabain (5 x 10-4 M) had little effect on the influx of Na or K and had no effect on Iinf or PD. Fluid was absorbed at a rate of about 93 pliter/cm2 sec. Reversing the direction of fluid movement by adding mannitol to the outside solution had little effect on ion movements. The ionic and electrical properties of normal and perfused cells of Valonia are compared.