The power motive, group conflict, and physiological arousal.

Tested D. C. McClelland's (1976; see also PA, Vol 68:12164) theory that persons high in power motivation experience high physiological reactivity to "power stress." A group of 192 male undergraduates, from which 64 group leaders were selected by means of the Thematic Apperception Test (TAT) as being high or low in the need for power (n Power), participated. The 128 Ss not designated as leaders served as group members. The experiment was a 2?×?2 factorial design, in which group conflict (high, low) served as the 1st factor and leader's n Power served as the 2nd factor, which yielded 4 conditions. Group discussion focused on a controversial proposal to market a new sunlamp. The group leader was wired for electromyographic (EMG) recordings and at the end of the experiment completed R. E. Thayer's (1967, 1970) Activation-Deactivation Adjective Check List. Analysis of variance for the EMG data disclosed a main effect for condition of the experiment and a marginally significant interaction effect. Consistent with McClelland's theory, the greatest EMG reactivity occurred in high-n-Power leaders subjected to group conflict. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mode selection schemes for unicasting device‐to‐device communications supported by network coding

Device‐to‐device (D2D) communication in a cellular spectrum increases the spectral and energy efficiency of local communication sessions, while also taking advantage of accessing licensed spectrum and higher transmit power levels than when using unlicensed bands. To realize the potential benefits of D2D communications, appropriate mode selection algorithms that select between the cellular and D2D communication modes must be designed. On the other hand, physical‐layer network coding (NWC) at a cellular base station—which can be used without D2D capability—can also improve the spectral efficiency of a cellular network that carries local traffic. In this paper, we ask whether cellular networks should support D2D communications, physical‐layer NWC, or both. To this end, we study the performance of mode selection algorithms that can be used in cellular networks that use physical‐layer NWC and support D2D communications. We find that the joint application of D2D communication and NWC scheme yields additional gains compared with a network that implements only one of these schemes, provided that the network implements proper mode selection and resource allocation algorithms. We propose 2 mode selection schemes that aim to achieve high signal‐to‐interference‐plus‐noise ratio and spectral efficiency, respectively, and take into account the NWC and D2D capabilities of the network.     

Absorption, distribution and elimination of fumonisin B1 metabolites in weaned piglets

The absorption, distribution and elimination of fumonisin B₁ (and B₂) after oral administration of Fusarium verticillioides (MRC 826) fungal culture, mixed into the experimental feed for 10 days, was studied in weaned barrows. In order to determine the absorption of FB₁ from the feed marked by chromium oxide, a special T-cannula was implanted into the distal part of pigs' ileum. During the feeding of toxin-containing diet (45 mg FB₁ kg^-1) and until the tenth day after the end of treatment, the total quantity of urine and faeces was collected and their toxin content analysed. At the end of the trial, samples of lung, liver, kidney, brain, muscle, and fat were also collected and their fumonisin content analysed by LC-MS. The fumonisins appeared to decrease the reduced glutathione content in blood plasma and red blood cell haemolysate, possibly associated with in vivo lipid peroxidation. From a data set of 80 individual data and the concentration and rate of C_r and fumonisins (FB₁, partially hydrolysed FB₁ and aminopentol) in the chymus, it could be established that the accumulative absorption of fumonisin B₁ was 3.9% ± 0.7%. In the chymus, the FB₁ conversions into aminopentol and partially hydrolysed FB₁ were 1.0 and 3.9%, respectively. The degree of metabolism in faeces was variable, although the main product was the partially hydrolysed form, with very small amounts of the aminopentol moiety being recovered. In the investigated tissues the FB₁ conversion to aminopentol and partially hydrolysed FB₁ was 30 and 20%, respectively.     

In vitro microbial metabolism of fumonisin B1

There is a lack of information on the effect of swine caecal microbiota on fumonisin metabolism. In this in vitro study, the biotransformation of fumonisin B₁ (FB₁) by the gut microbiota of adult, healthy pigs was examined. Suspensions of caecal contents and McDougall buffer solution were incubated anaerobically with pure FB₁ for 0, 12, 24, 48 and 72 h. After 48 h, the conversion of FB₁ to partially hydrolysed FB₁ (46%) was nearly equal to the percentage ratio of FB₁, while by 72 h it was 49%. In vitro, the conversion of fumonisin B₁ to aminopentol was less than 1%. The results show that the caecal microbiota are capable of transforming fumonisin B₁ to the above metabolites. Further studies on FB₁ metabolism in the small intestine are clearly justified.     

Multienzymatic immobilization of laccases on polymeric microspheres: A strategy to expand the maximum catalytic efficiency

Laccase enzymes of were covalently coimmobilized on poly(glycidyl methacrylate) microspheres. The objective of this work was to create a biocatalyst that works efficiently in a wide range of pH. The coimmobilization was performed using two different strategies to compare the most efficient. The results showed that by correctly selecting the enzymes and concentrations involved in the commobilization, it is possible to obtain a biocatalyst that works efficiently at a wide pH range (2.0–7.0). The maximum activity values reached per gram of support for the obtained biocatalyst were 41.90 U (pH 3.0), 40.89 U (pH 4.0), and 39.54 U (pH 6.0). Moreover, the thermal, storage, and mechanical stabilities were improved compared to the free and single-immobilized laccases. It was concluded that enzymatic coimmobilization is an excellent alternative to obtain a robust biocatalyst that works in a wide pH range, with potential environmental and industrial applications.     

Ein Speicher-Durchfluss-Modell für die Abflussbildung im Oberjura-Karst der Schwäbischen Alb

Upper Jurassic karstified limestones in southern Germany are characterized by a dual-porosity system. Here we present a new model that describes the basic processes from recharge to discharge. While recharge is distributed to both main conduits and fractures, only minor amounts of the total runoff reach the karst system directly (direct runoff) while most water infiltrates into the fractured matrix. This mechanism expels pre-event water from the fissured matrix and into karst conduits. Additionally, matrix storage exponentially decreases during baseflow conditions. Altogether, direct runoff, pre-event water and baseflow fill the karst system and make up the spring discharge. Based on a time series of 40 years of recharge data, the model simulates daily changes of groundwater volumes within the two storage systems. Prerequisites are recession coefficients for baseflow and conduits. A distribution coefficient calculates the amount of direct runoff and a second coefficient the amount of pre-event water. Calculated discharges were in good agreement with the spring hydrograph.     

Learning from Network Device Statistics

We estimate end-to-end service metrics from network device statistics. Our approach is based upon statistical, supervised learning, whereby the mapping from device-level to service-level metrics is learned from observations, i.e., through monitoring the system. The approach enables end-to-end performance prediction without requiring an explicit model of the system, which is different from traditional engineering techniques that use stochastic modeling and simulation. The fact that end-to-end service metrics can be estimated from local network statistics with good accuracy in the scenarios we consider suggests that service-level properties are “encoded” in network-level statistics. We show that the set of network statistics needed for estimation can be reduced to a set of measurements along the network path between client and service backend, with little loss in estimation accuracy. The reported work is largely experimental and its results have been obtained through testbed measurements from a video streaming service and a KV store over an OpenFlow network .     

A systematic review on the use of quantitative imaging to detect cancer therapy adverse effects in normal-appearing brain tissue

Cancer therapy for both central nervous system (CNS) and non-CNS tumors has been previously associated with transient and long-term cognitive deterioration, commonly referred to as ‘chemo fog’. This therapy-related damage to otherwise normal-appearing brain tissue is reported using post-mortem neuropathological analysis. Although the literature on monitoring therapy effects on structural magnetic resonance imaging (MRI) is well established, such macroscopic structural changes appear relatively late and irreversible. Early quantitative MRI biomarkers of therapy-induced damage would potentially permit taking these treatment side effects into account, paving the way towards a more personalized treatment planning.

This systematic review (PROSPERO number 224196) provides an overview of quantitative tomographic imaging methods, potentially identifying the adverse side effects of cancer therapy in normal-appearing brain tissue. Seventy studies were obtained from the MEDLINE and Web of Science databases. Studies reporting changes in normal-appearing brain tissue using MRI, PET, or SPECT quantitative biomarkers, related to radio-, chemo-, immuno-, or hormone therapy for any kind of solid, cystic, or liquid tumor were included. The main findings of the reviewed studies were summarized, providing also the risk of bias of each study assessed using a modified QUADAS-2 tool. For each imaging method, this review provides the methodological background, and the benefits and shortcomings of each method from the imaging perspective. Finally, a set of recommendations is proposed to support future research.

     

Better than $l/Mflops sustained: a scalable PC-based parallel computer for lattice QCD

We study the feasibility of a PC-based parallel computer for medium to large scale lattice QCD simulations. The Eötvös Univ., Inst. Theor. Phys. cluster consists of 137 Intel P4-1.7GHz nodes with 512 MB RDRAM. The 32-bit, single precision sustained performance for dynamical QCD without communication is 1510 Mflops/node with Wilson and 970 Mflops/node with staggered fermions. This gives a total performance of 208 Gflops for Wilson and 133 Gflops for staggered QCD, respectively (for 64-bit applications the performance is approximately halved). The novel feature of our system is its communication architecture. In order to have a scalable, cost-effective machine we use Gigabit Ethernet cards for nearest-neighbor communications in a two-dimensional mesh. This type of communication is cost effective (only 30% of the hardware costs is spent on the communication). According to our benchmark measurements this type of communication results in around 40% communication time fraction for lattices upto 48³·96 in full QCD simulations. The price/sustained-performance ratio for full QCD is better than $l/Mflops for Wilson (and around $1.5/Mflops for staggered) quarks for practically any lattice size, which can fit in our parallel computer. The communication software is freely available upon request for non-profit organizations.