Adaptive global power optimization for Web servers

This work investigates power and performance trade-offs for Web servers on a state-of-the-art, high-density, power-efficient SeaMicro SM15k cluster by AMD. We relied on the concept of virtual power states (VPSs), a combination of CPU utilization rate to the P/C power states available in modern processors, and on our global optimization algorithm called Slack Recovery, to deploy an adaptive global power management system in a production environment. The main contributions of this paper are twofold. First, it presents the Slack Recovery algorithm deployed on a real cluster, composed of 25 SeaMicro nodes. The algorithm finds a P-state and a utilization rate for each CPU node to minimize power under a minimum performance requirement. Second, it proposes a novel mechanism to control utilization rates in each server, a key aspect on our power/performance optimization system which enables the implementation of the VPS concept in practice. Experimental results show that our Slack Recovery-based system can reduce up to 6.7 % of the power consumption when compared to policies usually deployed in SeaMicro production systems.     

Alcohol-impaired driving behavior and sensation-seeking disposition in a college population receiving routine care at campus health services centers

Accidents stemming from alcohol-impaired driving are the leading cause of injury and death among college students. Research has implicated certain driver personality characteristics in the majority of these motor vehicle crashes. Sensation seeking in particular has been linked to risky driving, alcohol consumption, and driving while intoxicated. This study investigated the effect of sensation seeking on self-reported alcohol-impaired driving behavior in a college student population while adjusting for demographics, residence and drinking locations. A total of 1587 college students over the age of 18 completed a health screening survey while presenting for routine, non-urgent care at campus heath services centers. Student demographics, living situation, most common drinking location, heavy episodic drinking, sensation-seeking disposition and alcohol-impaired driving behavior were assessed. Using a full-form logistic regression model to isolate sensation seeking after adjusting for covariates, sensation seeking remains a statistically significant independent predictor of alcohol-impaired driving behavior (OR = 1.52; CI = 1.19-1.94; p < 0.001). Older, white, sensation-seeking college students who engage in heavy episodic drinking, live off-campus, and go to bars are at highest risk for alcohol-impaired driving behaviors. Interventions should target sensation seekers and environmental factors that mediate the link between sensation seeking and alcohol-impaired driving behaviors.     

Investigation of the thermal properties of a Li-ion pouch-cell by electrothermal impedance spectroscopy

Electrothermal impedance spectroscopy (ETIS), is introduced as a new measurement method and thermal parameters derived from a pouch-type lithium-ion cell are presented. ETIS is a valuable tool for (i) the determination of the thermal impedance and (ii) the validation of thermal models. The excitation signal applied to the cell during measurement does not cause a change in entropy, thus facilitating the parameter identification of a thermal model for heat conduction and thermal capacity.ETIS can be applied to measurements in time domain and in frequency domain. Both approaches are presented and a combination further improves measurement time and accuracy.     

Electrochemical performances of solid oxide fuel cells based on Y-substituted SrTiO3 ceramic anode materials

Yttrium-substituted SrTiO₃ has been considered as anode material of solid oxide fuel cells (SOFCs) substituting of the state-of-the-art Ni cermet anodes. Sr_0.895Y_0.07TiO_3−δ (SYT) shows good electrical conductivity, compatible thermal expansion with yttria-stabilized ZrO₂ (YSZ) electrolyte and reliable stability during reduction and oxidation (redox) cycles. Single cells based on SYT anode substrates were fabricated in the dimension of 50 mm × 50 mm. The cell performances were over 1.0 A cm⁻² at 0.7 V and 800 °C, which already reached the practical application level. Although Ti diffusion from SYT substrates to YSZ electrolytes was observed, it did not show apparent disadvantage to the cell performance. The cells survived 200 redox cycles without obvious OCV decrease and macroscopic damage, but performance decreased due to the electronic properties of the SYT material. The influence of water partial pressure on cell performance and coking tolerance of the cells are also discussed in this study.     

Altered ingestive behavior, weight changes, and intact olfactory sense in an APP overexpression model.

Transgenic APP23 mice were generated to model Alzheimer's disease. The APP23 model develops pathological features, learning deficits, and memory deficits analogous to dementing patients. In this report, transgenic mice exhibited several behavioral disturbances indicating the presence of neuropsychiatric symptoms of dementia. Aiming to verify whether the model also develops other behavioral problems, the authors investigated ingestive behavior in APP23 males of 3, 6 and 12 months. In addition, body weights of a naive male group were longitudinally monitored starting at weaning. Olfactory acuity was evaluated in mice of different age groups. Although olfactory functioning of APP23 mice appeared intact, they drank more and took more food pellets compared with wild-type littermates during a 1-week registration period. From the age of 4.5 weeks onward, APP23 males weighed significantly less than their control littermates, whereas this difference became more prominent with increasing age. Our results suggest the presence of a hypermetabolic state in this model. This is the first report, evidencing the presence of changes in eating and drinking behavior in a single transgenic Alzheimer mouse model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the antibacterial effect of a triclosan-containing floor used in the food industry

Antibacterial surfaces are increasingly used in the food industry. In the present study, the antibacterial effect of a triclosan-containing industrial floor was assessed. A poultry processing plant, which had a floor that contained triclosan, was visited, and the floor was sampled for bacteria. A high bacterial diversity was found on the floor. Testing showed that bacteria isolated from the floor showed a sensitivity to triclosan that covered a range of MICs from 0.07 to >40 ppm. Staphylococci were the most sensitive, and Pseudomonas fluorescens and Serratia marcescens were the most tolerant. The MICs of triclosan for the strains isolated from the floor were similar to the control strains from the corresponding genera or species of other origin. Thus, the floor seemed not to select for strains that were tolerant to triclosan or that led to the development of resistance to triclosan. Laboratory studies showed that the ability of bacteria to survive under dry conditions on coupons of the floor was similar to that for stainless steel and that the survival of the bacteria on the floor was not linked to their tolerance of triclosan, as determined by the MICs of triclosan. Adherence studies showed that bacteria were able to adhere to coupons of the floor; however, no thick biofilm developed after 3 days of incubation. In an agar plate assay, the floor produced inhibition zones against staphylococci, which are known to be very sensitive to triclosan, whereas no inhibition zones were observed for other bacteria tested. In conclusion, the antibacterial effect of the floor seemed to be very low. Because the concentration of triclosan in the floor was low compared to what has been reported for other triclosan-incorporated surfaces, sufficient amounts of triclosan may not have been available on the surface of the floor to kill the bacteria.     

Effect of preslaughter events on the prevalence of Salmonella in market-weight turkeys

The goal of this study was to determine if preslaughter events, such as transport to and holding at the slaughterhouse, affect Salmonella prevalence in turkeys. Floors of transport crates were swabbed after loading and prior to transport at the farm (time 1, n = 100 swabs per trial) and after transport to and holding at the abattoir (time 2, n = 100 swabs per trial). In addition, environmental samples were taken at each of the six premises (n = 25 per premises) as well as in the holding shed at the abattoir (n = 25 samples per trial). At slaughter, the crops, ceca, and spleens were cultured (n = 50 each per flock). As shown from the culture of the crate floor swabs collected pre- and posttransport, when individual farms were analyzed, samples from only one premises exhibited a statistically significant change, as seen by the decline in Salmonella prevalence posttransport (P < 0.01). When the data from all farms were combined, Salmonella was recovered more frequently from swabs collected pretransport at loading on-farm (time 1, 47.6%) than from swabs collected after transport (time 2, 39.7%, P < 0.01). This suggests that transport to and holding at the abattoir do not increase the prevalence of Salmonella in turkeys. This observation contrasts with the increase in Salmonella prevalence reported for hogs and some broilers.     

Der fotograf der goldenen zwanziger Jahre

Abstract

Fragmentation involves anteriority, decay, and loss in relation to some superseded whole. As excerpts from a world that was, photographs are understandable as fragments, which means that they carry with them an invitation to reflect on and even to reconstruct former environments and totalities. The history of photography is a history of responses to that invitation, most of which are studiedly hesitant and doubtful of an outcome. One reason for this hesitation is that photographs seem to exist in a perpetual present, which means that photography inevitably has reservations about the past as past. If its personnel still exist, and if its events are still in progress, photographic representations would be better termed presentations. They belong, even if seemingly so, to an everyday in process, where everything is still to be resolved.¹     

Antibiotic resistant enterococci and staphylococci isolated from flies collected near confined poultry feeding operations

Use of antibiotics as feed additives in poultry production has been linked to the presence of antibiotic resistant bacteria in farm workers, consumer poultry products and the environs of confined poultry operations. There are concerns that these resistant bacteria may be transferred to communities near these operations; however, environmental pathways of exposure are not well documented. We assessed the prevalence of antibiotic resistant enterococci and staphylococci in stored poultry litter and flies collected near broiler chicken houses. Drug resistant enterococci and staphylococci were isolated from flies caught near confined poultry feeding operations in the summer of 2006. Susceptibility testing was conducted on isolates using antibiotics selected on the basis of their importance to human medicine and use in poultry production. Resistant isolates were then screened for genetic determinants of antibiotic resistance. A total of 142 enterococcal isolates and 144 staphylococcal isolates from both fly and poultry litter samples were identified. Resistance genes erm(B), erm(A), msr(C), msr(A/B) and mobile genetic elements associated with the conjugative transposon Tn916, were found in isolates recovered from both poultry litter and flies. Erm(B) was the most common resistance gene in enterococci, while erm(A) was the most common in staphylococci. We report that flies collected near broiler poultry operations may be involved in the spread of drug resistant bacteria from these operations and may increase the potential for human exposure to drug resistant bacteria.