Prosthetic urinary sphincter

A pump/valve unit for controlling the inflation and deflation of a urethral collar in a prosthetic urinary sphincter device is described. A compressible bulb pump defining a reservoir was integrated with a valve unit for implantation. The valve unit includes a movable valve member operable by depression of a flexible portion of the valve unit housing for controlling fluid flow between the reservoir and collar; and a pressure sensing means which operates the valve member to relieve an excess pressure in the collar should too much pressure be applied by the patient

Closed-loop recycling of plastics enabled by dynamic covalent diketoenamine bonds.

Recycled plastics are low-value commodities due to residual impurities and the degradation of polymer properties with each cycle of re-use. Plastics that undergo reversible polymerization allow high-value monomers to be recovered and re-manufactured into pristine materials, which should incentivize recycling in closed-loop life cycles. However, monomer recovery is often costly, incompatible with complex mixtures and energy-intensive. Here, we show that next-generation plastics-polymerized using dynamic covalent diketoenamine bonds-allow the recovery of monomers from common additives, even in mixed waste streams. Poly(diketoenamine)s 'click' together from a wide variety of triketones and aromatic or aliphatic amines, yielding only water as a by-product. Recovered monomers can be re-manufactured into the same polymer formulation, without loss of performance, as well as other polymer formulations with differentiated properties. The ease with which poly(diketoenamine)s can be manufactured, used, recycled and re-used-without losing value-points to new directions in designing sustainable polymers with minimal environmental impact

Hydrological simulation of extreme flood scenarios for operational flood management at the Middle Elbe river

Operational flood management at the Middle Elbe river requires comprehensive knowledge about the magnitude and characteristics of possible extreme flood events. Since these events are not sufficiently included in available historical records, an extended sample of extreme flood events was generated by hydrological scenario simulation. Present paper emphasises simulations in the German part of the catchment of the Middle Elbe river and introduces the stochastic-conceptual precipitation-runoff model which was developed for this task. After validation of this model and its coupling with the weather forecast model COSMO and hydraulic-numerical models, a set of 25 flood scenarios could be simulated and provided for a planning of flood protection measures. Analysis of simulated scenarios reveal that extreme flood events at the Mulde and Middle Elbe rivers may have a wide spectrum of characteristics and may considerably exceed the magnitude of past flood events (e.g., those of August 2002)

Corporate Governance Reform and Reemergence from Bankruptcy: Putting the Structure Back in Restructuring

A company\u27s descent into bankruptcy may result from one or more troubling factors. Often the failing enterprise has adopted a poor business model, been led by deficient management, or labored under an unworkable capital structure. More often than not, a business failure is also accompanied by a less-than-ideal corporate governance structure within the organization. The failure to adopt an effective corporate governance model often leads to a sterile, inactive board of directors and may hasten a firm\u27s demise. Conversely, proper corporate governance may prevent a business\u27s slide into Chapter 11. Indeed, several studies have demonstrated a strong relationship between corporate performance and effective corporate governance.\u27 Board independence and equity ownership, along with the mantras of good governance, can create an environment in which management is effectively monitored and bankruptcy generally is avoided. But what happens when an organization does fail? Traditionally, the focus in Chapter 11 restructurings has been on financial and managerial reform, largely ignoring equally important issues of firm governance. Attention to governance concerns, however, can greatly benefit firms emerging from bankruptcy. In reorganization, a failed firm stands at a critical juncture at which it must take a course of action that will ensure its successful revival. This course of action must include the restructuring of its corporate governance structure to incorporate, inter alia, both the election of independent outside directors and the use of equity ownership to incentivize these directors to effectively monitor management. In order to promote the firm\u27s sound future, the debtor must undertake both this corporate restructuring and the traditional financial and managerial restructuring that occurs during Chapter 11. Business leaders within the firm, institutional investors, and even bankruptcy judges can influence and encourage a firm\u27s decision to reform its governance structure. Indeed, many institutional investors currently demand the placement of independent, outside directors on the board prior to any infusion of additional capital. Bankruptcy judges must utilize the feasibility requirement to inquire into the firm\u27s efforts at corporate governance reform, while the debtor company must create the kind of vital board that is crucial to its future survival and success. Whether on the road to or from bankruptcy, firms will benefit from adopting an effective corporate governance structure. The adoption of an independent board and an equity ownership plan, as urged by governance theorists, is an essential means of ensuring the firm\u27s successful emergence from reorganization, future survival, and performance

Genetic and Plant Growth Regulator Manipulation of Rice (Oryza sativa L.) Mesocotyl and Coleoptile Lengths

Significant differences in mesocotyl lengths of semidwarf and non-semidwarf rice (Oryza sativa L.) cultivars were observed. However, the relationship between plant height and mesocotyl length was found to be due to linkage rather than pleiotropism. Seed treatments of gibberellic acid (GA₃) significantly increased mesocotyl and coleoptile lengths in the laboratory study. The GA₃ seed treatments significantly increased stand density compared to the untreated control in the field study. However, no significant differences were observed for plant height at maturity or grain yields among the GA₃ treatments or the untreated control

Motherhood, Moral Authority and the Charismatic Matriarch in the Aftermath of Lethal Violence

Images of maternal suffering are an evocative and powerful means of communication in a world where the private grief of victims has increasingly become subject to commodification and public consumption. This article looks at the influence of bereaved mothers as symbols of respect, peace and dignity in the aftermath of violence, and as a result their persuasive presence in family activism. Drawing upon two case studies, this article explores the importance of victims’ stories in public life and, in particular, the presence of the charismatic matriarch in creating communities of solidarity, raising awareness of harms that have previously gone unheard and prompting policy change. It considers the ‘canonical’ story of the mother in public life and concludes by arguing that more attention should be paid to victims’ stories and their influence on policy-making, politics and eventually in becoming public grievances

Atomistic Simulation of Water Percolation and Proton Hopping in Nafion Fuel Cell Membrane

We have performed a detailed analysis of water clustering and percolation in hydrated Nafion configurations generated by classical molecular dynamics simulations. Our results show that at low hydration levels H2O molecules are isolated and a continuous hydrogen-bonded network forms as the hydration level is increased. Our quantitative analysis has established a hydration level (λ) between 5 and 6 H2O/SO3− as the percolation threshold of Nafion. We have also examined the effect of such a network on proton transport by studying the structural diffusion of protons using the quantum hopping molecular dynamics method. The mean residence time of the proton on a water molecule decreases by 2 orders of magnitude when the λ value is increased from 5 to 15. The proton diffusion coefficient in Nafion at a λ value of 15 is about 1.1 × 10−5 cm2/s in agreement with experiment. The results provide quantitative atomic-level evidence of water network percolation in Nafion and its effect on proton conductivity

Conformational Entropy as a Means to Control the Behavior of Poly(diketoenamine) Vitrimers In and Out of Equilibrium.

Control of equilibrium and non-equilibrium thermomechanical behavior of poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) and conformational degrees of freedom into the dynamic covalent network. While increasing MW of linear segments yields a lower storage modulus at the rubbery plateau after softening above the glass transition (Tg ), both Tg and the characteristic time of stress relaxation are independently governed by the conformational entropy of the embodied linear segments. Activation energies for bond exchange in the solid state are lower for networks incorporating flexible chains; the network topology freezing temperature decreases with increasing MW of flexible linear segments but increases with increasing MW of stiff segments. Vitrimer reconfigurability is therefore influenced not only by the energetics of bond exchange for a given network density, but also the entropy of polymer chains within the network