CrossTalk: cross-layer decision support based on global knowledge

The dynamic nature of ad hoc networks makes system design a challenging task. Mobile ad hoc networks suffer from severe performance problems due to the shared, interference-prone, and unreliable medium. Routes can be unstable due to mobility and energy can be a limiting factor for typical devices such as PDAs, mobile phones, and sensor nodes. In such environments cross-layer architectures are a promising new approach, as they can adapt protocol behavior to changing networking conditions. This article introduces CrossTalk, a cross-layer architecture that aims at achieving global objectives with local behavior. It further compares CrossTalk with other cross-layer architectures proposed. Finally, it analyzes the quality of the information provided by the architecture and presents a reference application to demonstrate the effectiveness of the general approach.     

Adult spinal deformity and respiratory failure. Surgical results in 35 patients

STUDY DESIGN: Retrospective chart and complementary study review. OBJECTIVES: To describe the features of adult patients with spinal deformity and respiratory failure and to analyze the results of surgical treatment. SUMMARY OF BACKGROUND DATA: Many authors have studied the relation between spinal deformities and cardiorespiratory failure, but there exists little information about the benefits of reconstructive surgery in severely compromised patients. METHODS: The charts and complementary studies of 35 adult patients surgically treated between January 1, 1978, and December 31, 1994, were reviewed. The patients were 18 years old or older (average age, 36 years). They had spinal deformity of any etiology with respiratory insufficiency as evidenced by vital capacity of less than 60% of predictive normal, PaO2 less than 80 mm Hg, or PaCO2 more than 45 mm Hg. All had reconstructive spinal surgery in an attempt to improve their respiratory problem. RESULTS: Seven patients died within the first postoperative year, and one patient was lost to follow-up at 6 months. The other 27 patients had a mean follow-up time of 72 months. The 34 patients were divided into three groups: good, fair, and poor evolution. The patients in the good evolution group had a better preoperative general condition, had more correction of their deformities, had more improvement in their respiratory function, and had fewer complications than those in the other groups. The patients in the poor evolution group were older, had more cardiac problems, and had less correction at surgery. CONCLUSION: The results of surgery varied from extremely good to extremely bad. The seven patients who died within the first year had no benefit, but the 27 others did very well, usually gaining significant improvement of their respiratory function. Because the alternative to surgical correction is death, this study shows that, under the right circumstances, correction of spinal deformity and, therefore, correction of respiratory function can be life-saving.     

Structure and rheology of twin liquid crystalline polymers

Addition of short mesogenic segments at the ends of flexible chains alters the mechanical properties by orders of magnitude. Twin liquid crystalline polymers (TLCPs) were synthesized from 4-[(4′-alkoxybenzoyl)oxy]-benzoyl chloride and ,ω-dihydroxy-telechelic polytetrahydrofuran (PTHF) of different molecular weights. With increasing temperature, four equilibrium states of these TLCPs, i.e. crystalline state, phase separated state with mesogenic domains in isotropic PTHF matrix, phase separated amorphous state, and single phase isotropic state, have been observed by dynamic mechanical measurements, differential scanning calorimetry and polarizing microscopy. In the phase separated state, mesogenic domains function as physical crosslinks which give rise to unusually high viscoelastic properties at small strains. Disturbing this state by large amplitude shear resulted in very pronounced shear thinning and slow recovery of structure. At increased temperature, the mesogenic domains become isotropic and their effect as physical crosslinks was significantly reduced, as shown by lower viscoelasticity and weak shear thinning. In the single phase isotropic state above the coexistence temperature T_s, the TLCPs behaved like a common homopolymer of low molecular weight. T_s decreased as the weight ratio of PTHF spacer increased in the experimental range (50–82% PTHF).     

Personality differences in spontaneous personality inferences at encoding.

Examined the relationship between individual differences on a trait measure with behavioral correlates—a balanced authoritarianism (F) scale developed by D. Byrne (1974)—and the content of stimulus sentences and their related dispositional retrieval cues. Two sets of sentences were developed in pretesting with 33 undergraduates. In the 1st set, events suggested a consensual disposition for each sentence actor to either high-F (HF) or low-F (LF) Ss. In the 2nd set, events suggested a different consensual disposition to HF and LF Ss. 38 HF and 39 LF undergraduates then read both sets of sentences for a "memory study." Consensual dispositions and semantic associates to the actors were used to cue recall. For the 1st set, there was a significant interaction between S type, sentence type, and cue type. LF dispositions were more effective retrieval cues for LF than for HF Ss. Ss had little accurate awareness of having made trait inferences. No significant effects were found for HF cues alone or for the 2nd sentence set. Results indicate that HF and LF Ss differ in their spontaneous social inferences about others and have little awareness of making these inferences. Implications for integrating trait and cognitive approaches to personality are discussed. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combination of redox capacity and double layer capacitance in composite electrodes through immobilization of an organic redox couple on carbon black

Carbon electrodes have been modified with 2-nitro-1-naphthol with the aim of producing composite supercapacitor electrodes, which make use of both the electric double layer (EDL) capacitance of high surface area carbon and the redox capacity (pseudocapacitance) of the organic compound. In situ FTIR and cyclic voltammetric data confirm literature reports of the reduction of 2-nitro-1-naphthol to 2-amino-1-naphthol and the subsequent oxidation of the o-aminonaphthol to the corresponding o-naphthaquinoneimine in aqueous acidic media. The measurements also show that the quinoneimine is not stable and hydrolized in sulphuric acid electrolyte to 1,2-naphthaquinone. The chemically highly reversible o-naphthaquinone/o-naphthahydroquinone couple remains immobilized on the carbon electrodes during redox cycling. The organic redox couple contributes a capacity of 35 mA h g⁻¹ of the bare carbon to the overall charge storage capability of the composite electrode. Surprisingly, it does not affect the capacitance of the electric double layer of the carbon. During 1000 charge/discharge cycles, the pseudocapacitance decreases by less than 20% in a normal large-volume electrochemical cell. Electrochemical impedance measurements show that the full capacity of the electrode is accessible at frequencies below 0.1 Hz.     

Effect of clenbuterol on athletic performance

Unlike inhaled beta 2-agonists, more studies need to be performed before the action of systemic beta 2-agonists on athletic performance can be assessed accurately. Experiments in animals with oral clenbuterol have shown augmentation in muscle bulk across numerous species, but human studies cannot confirm similar muscle mass enlargement in healthy men. Although the human studies demonstrate the potential for long-acting systemic beta 2-agonists to increase muscle strength in certain muscle fiber types, it is difficult to judge the drugs' effects on overall athletic performance, because athletic skill is more than strength, speed, and endurance. The effect of oral clenbuterol on athletic performance cannot be evaluated from its actions on muscle strength alone. However, as evidence stands now, sports regulatory agencies are correct to ban systemic beta 2-agonists until the following 2 points can be proven: (1) oral forms provide a therapeutic benefit that cannot be obtained with aerosol or inhaled forms; and (2) oral forms do not give any unfair advantage to the competitor in muscle strength, power output, or endurance. Provided they are administered as prescribed, aerosol or inhaled beta-agonists do not impart an unfair advantage or enhance athletic performance and can continue to be used in competition by athletes with EIA.     

Electricity System Reliability Issues During Energy System Transformation

Energy system transformation in the electric energy industry encompasses a broad range of changes in how primary energy is produced, transported, converted, priced, and delivered to consumers. Minnesota Power (ALLETE) is responding to these changes by implementing strategies like our EnergyForward resource strategy. EnergyForward describes the transition to a diverse and balanced generation portfolio that meets customers' desires for clean, safe, flexible, and affordable electricity.