bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling critical sections in Amdahl's law and its implications for multicore design
Authors: Eyerman Stijn , Eeckhout Lieven
Published: October 2012

This paper presents a fundamental law for parallel performance: it shows that parallel performance is not only limited by sequential code (as suggested by Amdahl's law) but is also fundamentally limited by synchronization through critical sections. Extending Amdahl's software model to include critical sections, we derive the surprising result that the impact of critical sections on parallel performance can be modeled as a completely sequential part and a completely parallel part. The sequential part is determined by the probability for entering a critical section and the contention probability (i.e., multiple threads wanting to enter the same critical section). This fundamental result reveals at least three important insights for multicore design. (i) Asymmetric multicore processors deliver less performance benefits relative to symmetric processors than suggested by Amdahl's law, and in some cases even worse performance. (ii) Amdahl's law suggests many tiny cores for optimum performance in asymmetric processors, however, we find that fewer but larger small cores can yield substantially better performance. (iii) Executing critical sections on the big core can yield substantial speedups, however, performance is sensitive to the accuracy of the critical section contention predictor.
Elastic cooperative caching
Authors: Herrero Enric , González José , Canal Ramon
Published: October 2012

Next generation tiled microarchitectures are going to be limited by off-chip misses and by on-chip network usage. Furthermore, these platforms will run an heterogeneous mix of applications with very different memory needs, leading to significant optimization opportunities. Existing adaptive memory hierarchies use either centralized structures that limit the scalability or software based resource allocation that increases programming complexity.

We propose Elastic Cooperative Caching, a dynamic and scalable memory hierarchy that adapts automatically and autonomously to application behavior for each node. Our configuration uses elastic shared/private caches with fully autonomous and distributed repartitioning units for better scalability. Furthermore, we have extended our elastic configuration with an Adaptive Spilling mechanism to use the shared cache space only when it can produce a performance improvement. Elastic caches allow both the creation of big local private caches for threads with high reuse of private data and the creation of big shared spaces from unused caches. Local data allocation in private regions allows to reduce network usage and efficient cache partitioning allows to reduce off-chip misses.

The proposed scheme outperforms previous proposals by a minimum of 12% (on average across the benchmarks) and reduces the number of offchip misses by 16%. Plus, the dynamic and autonomous management of cache resources avoids the reallocation of cache blocks without reuse which results in an increase in energy efficiency of 24%.
Using hardware vulnerability factors to enhance AVF analysis
Authors: Sridharan Vilas , Kaeli David R.
Published: October 2012

Fault tolerance is now a primary design constraint for all major microprocessors. One step in determining a processor's compliance to its failure rate target is measuring the Architectural Vulnerability Factor (AVF) of each on-chip structure. The AVF of a hardware structure is the probability that a fault in the structure will affect the output of a program. While AVF generates meaningful insight into system behavior, it cannot quantify the vulnerability of an individual system component (hardware, user program, etc.), limiting the amount of insight that can be generated. To address this, prior work has introduced the Program Vulnerability Factor (PVF) to quantify the vulnerability of software. In this paper, we introduce and analyze the Hardware Vulnerability Factor (HVF) to quantify the vulnerability of hardware.

HVF has three concrete benefits which we examine in this paper. First, HVF analysis can provide insight to hardware designers beyond that gained from AVF analysis alone. Second, separating AVF analysis into HVF and PVF steps can accelerate the AVF measurement process. Finally, HVF measurement enables runtime AVF estimation that combines compile-time PVF estimates with runtime HVF measurements. A key benefit of this technique is that it allows software developers to influence the runtime AVF estimates. We demonstrate that this technique can estimate AVF at runtime with an average absolute error of less than 3%.
On greedy network formation
Authors: Gulyás András , Korösi Attila , Szabó Dávid , Biczók Gergely
Published: October 2012

Greedy navigability is a central issue in the theory of networks. However, the exogenous nature of network models do not allow for describing how greedy routable-networks emerge in reality. In turn, network formation games focus on the very emergence proess, but the applied shortest-path based cost functions exclude navigational aspects. This paper takes a frst step towards incorporating both emergence (missing in algorithmic network models) and greedy navigability (missing in network formation games) into a single framework, and proposes the Greedy Network Formation Game. Our first contribution is the game definition, where we assume a hidden metric space underneath the network, and, instead of usual shortest path metric, we use the length of greedy paths as the measure of communiation cost between players. Our main finding is that greedy-routable small worlds do not emerge on constant dimensional Eulidean grids. This simply means that the emergence of topologies on which w eunderstood the priniples of greedy forwarding cannot be explained endogenously. We also present a very brief outlook on how the situation hanges in the hyperbolic space.
Modeling performance through memory-stalls
Authors: Iakymchuk Roman , Bientinesi Paolo
Published: October 2012

We aim at modeling the performance of linear algebra algorithms without executing either them or parts of them. The performance of an algorithm can be expressed in terms of the time spent on CPU execution and on memory-stalls. The main concern of this paper is to build analytical models to accurately predict memory-stalls. The scenario in which data resides in the L2 cache is considered; with this assumption, only L1 cache misses occur. We construct an analytical formula for modeling the L1 cache misses of fundamental linear algebra operations such as those included in the Basic Linear Algebra Subprograms (BLAS) library. The number of cache misses occurring in higher-level algorithms "like a matrix factorization" is then predicted by combining the models for the appropriate BLAS subroutines. As case studies, we consider GER, a BLAS level-2 operation, and the LU factorization. The models are validated on both Intel and AMD processors, attaining remarkably accurate performance predictions.
A preliminary evaluation of the hardware acceleration of the Cray Gemini interconnect for PGAS languages and comparison with MPI
Authors: Shan Hongzhang , Wright Nicholas J. , Shalf John , Yelick Katherine , Wagner Marcus , Wichmann Nathan
Published: October 2012

The Gemini interconnect on the Cray XE6 platform provides for lightweight remote direct memory access (RDMA) between nodes, which is useful for implementing partitioned global address space (PGAS) languages like UPC and Co-Array Fortran. In this paper, we perform a study of Gemini performance using a set of communication microbenchmarks and compare the performance of one-sided communication in PGAS languages with two-sided MPI. Our results demonstrate the performance benefits of the PGAS model on Gemini hardware, showing in what circumstances and by how much one-sided communication outperforms two-sided in terms of messaging rate, aggregate bandwidth, and computation and communication overlap capability. For example, for 8-byte and 2KB messages the one-sided messaging rate is 5 and 10 times greater respectively than the twosided one. The study also reveals important information about how to optimize one-sided Gemini communication.
Critical path-based thread placement for NUMA systems
Authors: Su ChunYi , Li Dong , Nikolopoulos Dimitrios S. , Grove Matthew , Cameron Kirk , de Supinski Bronis R.
Published: October 2012

Multicore multiprocessors use a Non Uniform Memory Architecture (NUMA) to improve their scalability. However, NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications may suffer performance loss, even if they are optimized for NUMA. In this paper, we present algorithms and a runtime system that optimize the execution of OpenMP applications on NUMA architectures. By collecting information from hardware counters, the runtime system directs thread placement and reduces performance penalties by minimizing the critical path of OpenMP parallel regions. The runtime system uses a scalable algorithm that derives placement decisions with negligible overhead. We evaluate our algorithms and the runtime system with four NPB applications implemented in OpenMP. On average the algorithms achieve between 8.13% and 25.68% performance improvement, compared to the default Linux thread placement scheme. The algorithms miss the optimal thread placement in only 8.9% of the cases.
Identification of a nonselective cation channel in isolated lens fiber cells that is activated by cell shrinkage
Authors: Gunning S. J. , Chung K. K. H. , Donaldson Paul J. , Webb K. F.
Published: October 2012

The initiation of lens cataract has long been associated with the development of a membrane “leak” in lens fiber cells that depolarizes the lens intracellular potential and elevates intracellular Na+ and Ca2+ concentrations. It has been proposed that the leak observed in cataractous lenses is due to the activation of a nonselective cation (NSC) conductance in the normal electrically tight fiber cells. Studies of the membrane properties of isolated fiber cells using the patch-clamp technique have demonstrated a differentiation-dependent shift in membrane permeability from K+-dominated in epithelial and short fiber cells toward larger contributions from anion and NSC conductances as fiber cells elongate. In this study, the NSC conductances in elongating lens fiber cells are demonstrated to be due to at least two distinct classes: a Gd3+-sensitive, mechanosensitive channel whose blockade is essential for obtaining viable isolated fiber cells, and a second Gd3+-insensitive, La3+-sensitive conductance that appears to be activated by cell shrinkage. This second conductance was eliminated by the replacement of extracellular Na+ with the impermeant cation N-methyl- d-glucamine and was potentiated by both hypertonic stress and isosmotic cell shrinkage evoked by the replacement of extracellular Cl− with the impermeant anion gluconate. This additional cation conductance may play a role in normal lens physiology by mediating regulatory volume increase under osmotic or other physiological challenges. Since the inappropriate activation of NSC channels is implicated in the initiation of lens cataract, they represent potential targets for the development of novel anticataract therapies.
Epigenetic Methylation of ParathyroidCaRandVDRPromoters in Experimental Secondary Hyperparathyroidism
Authors: Hofman-Bang Jacob , Gravesen Eva , Olgaard Klaus , Lewin Ewa
Published: October 2012

Secondary hyperparathyroidism (s-HPT) in uremia is characterized by decreased expression in the parathyroids of calcium sensing (CaR) and vitamin D receptors (VDR). Parathyroid hormone (PTH) is normalized despite low levels ofCaRandVDRafter experimental reversal of uremia. The expression ofCaRin parathyroid cultures decreases rapidly. Methylation of promoter regions is often detected during epigenetic downregulation of gene expression. Therefore, using an experimental rat model, we examined changes in methylation levels of parathyroidCaRandVDRpromotersin vivoandin vitro.Methods. Uremia was induced by 5/6 nephrectomy. Melting temperature profiling ofCaRandVDRPCR products after bisulfite treatment of genomic DNA from rat parathyroids was performed. Real-time PCR measured expression ofPTH, CaR, VDR, andklothogenesin vitro.Results. Parathyroids from uremic rats had similar low levels of methylationin vivoandin vitro. In culture, a significant downregulation ofCaR, VDR, andklothowithin two hours of incubation was observed, while housekeeping genes remained stable for 24 hours.Conclusion. In uremic s-HPT andin vitro, no overall changes in methylation levels in the promoter regions of parathyroidCaRandVDRgenes were found. Thus, epigenetic methylation of these promoters does not explain decreased parathyroid expression ofCaRandVDRgenes in uremic s-HPT.
Bevacizumab-Induced Reversible Thrombocytopenia in a Patient with Adenocarcinoma of Colon: Rare Adverse Effect of Bevacizumab
Authors: Kumar Jeevan , Bhargava Manorama , Aggarwal Shyam
Published: October 2012

We report a case of bevacizumab- (BEV-) induced thrombocytopenia in a 59-year-old man with adenocarcinoma of colon. After colectomy, the patient was treated with twelve cycles of FOLFOX-4 (folinic acid, 5-fluorouracil, and oxaliplatin) regimen. On relapse, he was treated with FOLFIRI (folinic acid, 5-fluorouracil, and irinotecan) regimen along with BEV 10 mg/kg for 6 cycles. After that, BEV was continued for maintenance as a single agent at an interval of three weeks. After the13th cycle of BEV, the patient developed melena with epistaxis and thrombocytopenia, from which he recovered on withdrawal of BEV. On rechallenge with half the initial dose, there was once again a reversible drop in platelet count. The proposed mechanism of thrombocytopenia may be immune-mediated peripheral destruction of platelets.
Simvastatin Attenuates Contrast-Induced Nephropathy through Modulation of Oxidative Stress, Proinflammatory Myeloperoxidase, and Nitric Oxide
Authors: Al-Otaibi Ketab E. , Al Elaiwi Abdulrahman M. , Tariq Mohammad , Al-Asmari Abdulrahman K.
Published: October 2012

Contrast media- (CM-) induced nephropathy is a serious complication of radiodiagnostic procedures. Available data suggests that the development of prophylaxis strategies is limited by poor understanding of pathophysiology of CM-induced nephropathy. Present study was designed to determine the role of oxidative stress, myeloperoxidase, and nitric oxide in the pathogenesis of iohexol model of nephropathy and its modification with simvastatin (SSTN). Adult Sprague Dawley rats were divided into seven groups. After 24 h of water deprivation, all the rats except in control and SSTN-only groups were injected (10 ml/kg) with 25% glycerol. After 30 min, SSTN (15, 30, and 60 mg/kg) was administered orally, daily for 4 days. Twenty-four hours after the glycerol injection, iohexol was infused (8 ml/kg) through femoral vein over a period of 2 min. All the animals were sacrificed on day 5 and blood and kidneys were collected for biochemical and histological studies. The results showed that SSTN dose dependently attenuated CM-induced rise of creatinine, urea, and structural abnormalities suggesting its nephroprotective effect. A significant increase in oxidative stress (increased lipid hydroperoxides and reduced glutathione levels) and myeloperoxidase (MPO) and decreased nitric oxide in CM group were reversed by SSTN. These findings support the use of SSTN to combat CM-induced nephrotoxicity.
Parents' Beliefs about Children's Math Development and Children's Participation in Math Activities
Authors: Sonnenschein Susan , Galindo Claudia , Metzger Shari R. , Thompson Joy A. , Huang Hui Chih , Lewis Heather
Published: October 2012

This study explored associations between parents’ beliefs about children’s development and children’s reported math activities at home. Seventy-three parents were interviewed about the frequency of their children’s participation in a broad array of math activities, the importance of children doing math activities at home, how children learn math, parents’ role in their children’s math learning, and parents’ own math skills. Although the sample consisted of African Americans, Chinese, Latino, and Caucasian parents in the United States, the majority were Chinese or Caucasian. Several important findings emerged from this study. Parents’ beliefs about math development and their role in fostering it were significantly related to children’s math activities. There was important variability and relatively limited participation of children in math activities at home. There were age-related differences in children’s engagement in math activities. Chinese and Caucasian parents showed somewhat similar beliefs about how children developed math. Although further research is needed to confirm the findings with a larger sample and to include measures of children’s math competencies, these findings are an important step for developing home-based interventions to facilitate children’s math skills.
Effect of Metal Dopant on Ninhydrin—Organic Nonlinear Optical Single Crystals
Authors: Sreenivasan R. S. , Kanagathara N. , Ezhamani G. , Renganathan N. G. , Anbalagan G.
Published: October 2012

In the present work, metal (Cu2+)-substituted ninhydrin single crystals were grown by slow evaporation method. The grown crystals have been subjected to single crystal XRD, powder X-ray diffraction, FTIR, dielectric and SHG studies. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in monoclinic system with noncentrosymmetric space group P21 with lattice parametersa=11.28 Å,b=5.98 Å,c=5.71 Å,α=90∘,β=98.57,γ=90∘, andV=381 (Å)3, which agrees very well with the reported value. The sharp and strong peaks in the powder X-ray diffraction pattern confirm the good crystallinity of the grown crystals. The presence of dopants marginally altered the lattice parameters without affecting the basic structure of the crystal. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength 314 nm. The vibrational frequencies of various functional groups in the crystals have been derived from FT-IR analysis. Based on the shifts in the vibrations, the presence of copper in the lattice of the grown crystal is clearly established from the pure ninhydrin crystals. Both dielectric constant and dielectric loss decrease with the increase in frequency. The second harmonic generation efficiency was measured by employing powder Kurtz method.
Association of common thrombophilias and antiphospholipid antibodies with success rate of in vitro fertilisation
Authors: Berliner Shlomo , Steinberg David , Zeltser David , Levran David , Shimron Orit , Sella Tal , Chodick Gabriel , Shalev Varda , Steinvil Arie , Raz Raanan , Salomon Ophira
Published: October 2012

Assisted reproductive technology (ART) is extensively used as a tool for pregnancy achievement in subfertile couples. Congenital and acquired thrombophilias have been suggested by some investigators to play a role in abnormal embryo implantation and placentation. The objective of this study was to assess the role of common thrombophilias in women with unexplained infertility undergoing in vitrofertilisation (IVF). We retrospectively analysed 594 women from a large healthcare maintenance organisation going through IVF and who had a thrombophilia workup, and compared them for prevalence of thrombophilia to two reference groups consisting of 637 fertile women from previous work and 17,337 women members of the same healthcare organisation with no history of venous thromboembolism. The mean age of the women at the first cycle of IVF was 30.9 years (SD: 4.1).The mean number of IVF cycles was 7.3 (SD: 5.0), and the mean fertility success rate per woman was 14.6% (SD: 19.0%). None of the common thrombophilias tested was found to be significantly associated with the number of IVF cycles or with lower fertility success rate. Rather, women who had APCR and /or factor V Leiden and lupus anticoagulant had significantly higher live birth rates (12.3% and 12.6%, respectively) in comparison to women who were tested negative (9.0% and 9.7%, respectively). Thus, hypercoagulability is not associated with failure to achieve pregnancy. These data suggest that neither screening for thrombophilia nor anticoagulant treatment is indicated in cases with unexplained reproductive failure.
Direct Comparison of Percutaneous Circulatory Support Systems in Specific Hemodynamic Conditions in a Porcine Model
Authors: Ostadal Petr , Mlcek Mikulas , Holy Frantisek , Horakova Svatava , Kralovec Stepan , Skoda Jan , Petru Jan , Kruger Andreas , Hrachovina Vladimir , Svoboda Tomas , Kittnar Otomar , Reddy Vivek Y. , Neuzil Petr
Published: October 2012

Background—

Several percutaneous circulatory support systems have been recently introduced into clinical practice for the treatment of cardiogenic shock or refractory nontolerated ventricular tachycardia, in support of high-risk catheter interventions and, occasionally, cardiopulmonary resuscitation. To date, however, a direct comparison of the available systems has not been performed.

Methods and Results—

Adult female pigs (weight 50–60 kg) were used throughout the experiment. Under deep anesthesia and mechanical ventilation, 3 percutaneous circulatory support systems were compared: (1) right atrium-aorta, extracorporeal membrane oxygenation (n=4); (2) left atrium-aorta, TandemHeart system (n=4); (3) left ventricle-aorta, Impella 2.5 system (n=4), and (4) left ventricle-aorta with norepinephrine at 0.1 µg/kg per minute (n=4). Hemodynamic efficacy (mean arterial pressure) was measured at 3 specific conditions: ventricular pacing at 200 and 300 beats per minute, and ventricular fibrillation. Although no or only nonsignificant differences were found among the systems at ventricular pacing of 200 and 300 beats per minute, under ventricular fibrillation, the right atrium-aorta system was significantly the most efficacious, followed by the left atrium-aorta system and the left ventricle-aorta system (
P
<0.001). However, the left ventricle-aorta system with norepinephrine still maintained mean arterial pressure comparable with the left atrium-aorta system.

Conclusions—

Differences were seen in the hemodynamic efficacy of available percutaneous circulatory support systems, particularly under the most severe hemodynamic condition, ventricular fibrillation.
Dynamics and Practical Predictability of Extratropical Wintertime Low-Frequency Variability in a Low-Dimensional System
Authors: Inatsu Masaru , Nakano Naoto , Mukougawa Hitoshi
Published: October 2012

Dynamics and practical predictability of extratropical low-frequency variability (LFV) in Northern Hemisphere winter are examined in the framework of a two-dimensional (2D) stochastic differential equation (SDE) on the phase space spanned by two leading empirical orthogonal function modes of low-pass-filtered 500-hPa geopotential height variations. The drift vector and diffusion tensor of the 2D SDE with multiplicative noise are theoretically connected with deterministic and stochastic error growth, respectively; both are statistically estimated from a reanalysis dataset. Projected onto the 2D phase space is the practical predictability of the LFV estimated by the 10-day forecast spread based on the 1-month ensemble prediction operationally conducted by the Japan Meteorological Agency (JMA). It is shown that the forecast spread of the LFV prediction by the JMA model for a relatively shorter prediction period when the model bias does not hamper the forecast is primarily explained by the stochastic error growth associated with the diffusion tensor and the deterministic error growth due to the Jacobian of the drift vector plays a secondary role. A non-Gaussian PDF of the LFV is also related to the norm of the diffusion tensor. Hence, the stochastic processes mostly control the dynamics and predictability of the LFV in the 2D phase space.
Diva/BclB regulates differentiation by inhibiting NDPKB/Nm23H2-mediated neuronal differentiation in PC-12 cells
Authors: Lim Jasmin Qian Ru , Lu Jia , He Bei Ping
Published: October 2012

Background

Diva (

d
eath
i
nducer binding to
v
Bcl-2 and
A
paf-1)/BclB is a Bcl-2 family member, which is known for its function in apoptosis. Diva/BclB has been shown to interact with NDPKB/Nm23H2, which is involved in cellular differentiation. Thus far, there has been no direct evidence of Diva/BclB having a role in differentiation. In the present study, we investigated the expression of Diva/BclB and NDPKB/Nm23H2 during differentiation in PC-12 cell line.

Results

Our results show that after differentiation, Diva/BclB expression was decreased and reciprocally, NDPKB/Nm23H2 expression was increased and it translocated into the nucleus. Overexpression of NDPKB/Nm23H2 promoted PC-12 neuronal differentiation by increasing neurite outgrowth and arresting cell cycle progression. There was a concurrent downregulation of Diva/Boo when NDPKB/Nm23H2 was overexpressed, which mirrors the effect of NGF on PC-12 cell differentiation. Overexpression of Diva/BclB did not change the expression level of NDPKB/Nm23H2, but inhibited its nuclear localization. Cells that overexpressed Diva/BclB presented a decreased percentage of differentiated cells and average neurite length was shortened. This was due to an increase in the formation of Diva/BclB and NDPKB/Nm23H2 complexes as well as Diva/BclB and β-tubulin complexes. Concomitantly, there was a decrease in formation of NDPKB/Nm23H2 and β-tubulin complexes. Overexpression of Diva/BclB also resulted in a higher percentage of S-phase cells.

Conclusion

Our results showed a novel role for Diva/BclB in neuronal differentiation. Its downregulation during neuronal differentiation may be necessary to allow NDPKB/Nm23H2 and β-tubulin interaction that promotes NDPKB/Nm23H2 mediated differentiation.
Improved resistance to ischemia and reperfusion, but impaired protection by ischemic preconditioning in patients with type 1 diabetes mellitus: a pilot study
Authors: Engbersen Richard , Riksen Niels P , Mol Marc J , Bravenboer Bert , Boerman Otto C , Meijer Patrick , Oyen Wim JG , Tack Cees , Rongen Gerard A , Smits Paul
Published: October 2012

Background

In patients with type 1 diabetes mellitus (T1DM), cardiovascular events are more common, and the outcome following a myocardial infarction is worse than in nondiabetic subjects. Ischemic or pharmacological preconditioning are powerful interventions to reduce ischemia reperfusion (IR)-injury. However, animal studies have shown that the presence of T1DM can limit these protective effects. Therefore, we aimed to study the protective effect of ischemic preconditioning in patients with T1DM, and to explore the role of plasma insulin and glucose on this effect.

Methods

99mTechnetium-annexin A5 scintigraphy was used to detect IR-injury. IR-injury was induced by unilateral forearm ischemic exercise. At reperfusion, Tc-annexin A5 was administered, and IR-injury was expressed as the percentage difference in radioactivity in the thenar muscle between the experimental and control arm 4 hours after reperfusion. 15 patients with T1DM were compared to 21 nondiabetic controls. The patients were studied twice, with or without ischemic preconditioning (10 minutes of forearm ischemia and reperfusion). Patients were studied in either normoglycemic hyperinsulinemic conditions (n = 8) or during hyperglycemic normoinsulinemia (n = 7). The controls were studied once either with (n = 8) or without (n = 13) ischemic preconditioning.

Results

Patients with diabetes were less vulnerable to IR-injury than nondiabetic healthy controls (12.8 ± 2.4 and 11.0 ± 5.1% versus 27.5 ± 4.5% in controls; p < 0.05). The efficacy of ischemic preconditioning to reduce IR-injury, however, was lower in the patients and was even completely abolished during hyperglycemia.

Conclusions

Patients with T1DM are more tolerant to forearm IR than healthy controls in our experimental model. The efficacy of ischemic preconditioning to limit IR-injury, however, is reduced by acute hyperglycemia.

Trial Registration

The study is registered at www.clinicaltrials.gov (NCT00184821)
On fixed point theory in partial metric spaces
Authors: Alghamdi Maryam A , Shahzad Naseer , Valero Oscar
Published: October 2012

In this paper, we continue the study of contractive conditions for mappings in complete partial metric spaces. Concretely, we present fixed point results for weakly contractive and weakly Kannan mappings in such a way that the classical metric counterpart results are retrieved as a particular case. Special attention to the cyclical case is paid. Moreover, the well-posedness of the fixed point problem associated to weakly (cyclic) contractive and weakly (cyclic) Kannan mappings is discussed, and it is shown that these contractive mappings are both good Picard operators and special good Picard operators.
Sound Policy Trumps Politics: States Should Expand Medicaid
Authors: Frakt Austin B. , Carroll Aaron E.
Published: October 2012

By virtue of the Supreme Court's decision on the constitutionality of the Patient Protection and Affordable Care Act, states may reject the law's expansion of Medicaid without losing all Medicaid funding from the federal government. The Court's ruling potentially permits a range of Medicaid options for states, including some that may be very attractive from state officials' political perspectives. In the context of the presidential campaign, the uncompensated care problem, and their concerns about costs of expansion, state officials are weighing their options, and some have already pledged to opt out of expansion. We argue that despite the politics, expansion is in fact good for patients, providers, and taxpayers, and states should therefore comply.
King penguins adjust their diving behaviour with age
Authors: Le Vaillant Maryline , Wilson Rory P. , Kato Akiko , Saraux Claire , Hanuise Nicolas , Prud'Homme Onésime , Le Maho Yvon , Le Bohec Céline , Ropert-Coudert Yan
Published: October 2012

Increasing experience in long-lived species is fundamental to improving breeding success and ultimately individual fitness. Diving efficiency of marine animals is primarily determined by their physiological and mechanical characteristics. This efficiency may be apparent via examination of biomechanical performance (e.g. stroke frequency and amplitude, change in buoyancy or body angle, etc.), which itself may be modulated according to resource availability, particularly as a function of depth. We investigated how foraging and diving abilities vary with age in a long-lived seabird. During two breeding seasons, small accelerometers were deployed on young (5 year old) and older (8/9 year old) brooding king penguins (Aptenodytes patagonicus) at the Crozet Archipelago, Indian Ocean. We used partial dynamic body acceleration (PDBA) to quantify body movement during dive and estimate diving cost. During the initial part of the descent, older birds exerted more effort for a given speed but younger penguins worked harder in relation to performance at greater depths. Younger birds also worked harder per unit speed for virtually the whole of the ascent. We interpret these differences using a model that takes into account the upthrust and drag to which the birds are subjected during the dive. From this, we suggest that older birds inhale more at the surface but that an increase in the drag coefficient is the factor leading to the increased effort to swim at a given speed by the younger birds at greater depths. We propose that this higher drag may be the result of young birds adopting less hydrodynamic postures or less direct trajectories when swimming or even having a plumage in poorer condition.
Effect of mold surface antistiction treatment on microinjection replication quality using Cr-N/Zr-DLC thin-layer coating
Authors: Huang Ming-Shyan , Yang Yu-Sen , Hsu Wen-Shin , Nian Shih-Chih
Published: October 2012

Sticking in microinjection molds is a significant problem in controlling the qualities of molded parts such as replication rate and appearance. To resolve the problem, this study investigates the effect of chromium nitride (Cr-N) and diamond-like carbon that contains zirconium (Zr-DLC) layers deposited on mold inserts on the antisticking properties of molds. The injection-molded flat plate used is 0.4 mm thick and has 5, 10, and 20 μm high v-grooved microfeatures. To evaluate the importance of the major control factors in determining the microinjection molding quality and to obtain the optimal settings of those factors, the Taguchi method and analysis of variance were utilized. The sticking behaviors of the melt plastics on the cavities that were deposited Cr-N/Zr-DLC layers using an unbalanced magnetron sputtering process were studied with scanning electron microscopy. The experimental results indicate that an antistiction coating most strongly affects replication quality and is followed in that respect by the mold temperature and the barrel temperature. As the dimensions of the microfeatures decrease, the effect of the mold temperature on replication rate becomes more significant. In particular, a Zr-DLC coating on the mold surface yields a low coefficient of friction and a low resistance to the flow of polymer during cavity filling, improving the replication of the heights of the microfeatures. Nevertheless, a Cr-N coating provides better antisticking. This improvement follows from the lower stripping force, which results in the lower surface free energy on the Cr-N layers.
Fuzzy Pattern Trees: Ein alternativer Ansatz zur Fuzzy-Modellierung
Authors: Senge Robin , Fober Thomas , Nasiri Maryam , Hüllermeier Eyke
Published: October 2012

Dieser Beitrag stellt einen neuartigen Ansatz zur Modellierung von Fuzzy-Systemen vor, die so genannten Fuzzy Pattern Trees. Deren Motivation leitet sich vor allem aus vermeintlichen Schwächen klassischer regelbasierter Architekturen ab, die dieses Gebiet nach wie vor dominieren. Durch eine hierarchische, modulare Struktur sowie die Verwendung eines breiten Spektrums von (nichtlinearen) Aggregationsoperatoren ist ein Fuzzy Pattern Tree in der Lage, funktionale Abhängigkeiten zwischen Ein- und Ausgabegrößen auf sehr flexible Art und Weise und in sehr kompakter Form darzustellen. Hierdurch kann ein guter Kompromiss zwischen Modellgenauigkeit und Verständlichkeit erzielt werden. Neben der Erläuterung der wesentlichen Modellierungskonzepte geht der Beitrag speziell auf die Probleme der datenbasierten Modellanpassung sowie des automatisierten Lernens der Modellstruktur ein. Illustriert werden die Modelle anhand eines Färbeprozesses aus der Textilindustrie.
Transmembrane Proteins UNC-40/DCC, PTP-3/LAR, and MIG-21 Control Anterior–Posterior Neuroblast Migration with Left–Right Functional Asymmetry in Caenorhabditis elegans
Authors: Sundararajan Lakshmi , Lundquist Erik A
Published: October 2012

Migration of neurons and neural crest cells is of central importance to the development of nervous systems. In Caenorhabditis elegans, the QL neuroblast on the left migrates posteriorly, and QR on the right migrates anteriorly, despite similar lineages and birth positions with regard to the left–right axis. Initial migration is independent of a Wnt signal that controls later anterior–posterior Q descendant migration. Previous studies showed that the transmembrane proteins UNC-40/DCC and MIG-21, a novel thrombospondin type I repeat containing protein, act redundantly in left-side QL posterior migration. Here we show that the LAR receptor protein tyrosine phosphatase PTP-3 acts with MIG-21 in parallel to UNC-40 in QL posterior migration. We also show that in right-side QR, the UNC-40 and PTP-3/MIG-21 pathways mutually inhibit each other’s role in posterior migration, allowing anterior QR migration. Finally, we present evidence that these proteins act autonomously in the Q neuroblasts. These studies indicate an inherent left–right asymmetry in the Q neuroblasts with regard to UNC-40, PTP-3, and MIG-21 function that results in posterior vs. anterior migration.
Thermoelectric Properties of Crystallized Vanadate Glasses Prepared by Using Microwave Irradiation
Authors: Aoyagi Takuya , Fujieda Tadashi , Sawai Yuichi , Miyata Motoyuki , Naito Takashi , Yamamoto Hiroki
Published: October 2012

This study examined the crystallization of vanadate glasses by using microwave irradiation. A second aim was comparing the thermoelectric properties of crystallized glasses when using microwave irradiation to conventional heating. V2O5-P2O5-Fe2O3-CuO glasses were prepared by using the melt quenching method. These glasses were irradiated by 2.45-GHz microwaves and heated in an electric furnace. MxV2O5(M= Cu, Fe x=0.26-055) crystals were selectively precipitated by using the microwave irradiation. The crystal growth was also promoted by it. As a result, precipitation crystals formed a fiber-like structure. The electrical conductivity of the microwave irradiated glass was 6.3×101S/m at room temperature, which was three times higher than the value of conventionally-heated glass. The Seebeck coefficient of the microwave irradiated glass was -127 μV/K at room temperature, which was two times higher than that of conventionally-heated glass. This caused the power factor to be improved about 12 times. These results show that microwave irradiation is a potential candidate for obtaining conductive crystallized vanadate glasses.
Crystal Structure Analysis of the Cr2O3 thin films
Authors: Iwata Nobuyuki , Kuroda Takuji , Yamamoto Hiroshi
Published: October 2012

Using DC-RF magnetron sputtering method, the stress free c- and r-oriented Cr2O3 thin films were grown on c- and r-cut sapphire substrates, respectively. The c-oriented film grown at 580 ºC shows the smoothest surface with a surface average (Ra) of 0.17, although the c-surface energy is the highest. The origin of the smooth surface is expected that the presence of a twin grain due to a dislocation of Cr atoms, demonstrated by a reciprocal space mapping. The step height corresponding to that of the bulk is clearly observed. The r-oriented films epitaxially grow without twin grain. The Ra is 1.56 in the film grown at 580 ºC because of deep trenches due to a lattice mismatch and no dislocation like c-oriented films. Since the surface energy of the r-surface is the lowest, the terrace is quite smooth in one grain even at higher substrate temperature of 840 ºC.
Ultralong Lifetime of Active Surface of Oxygenated PET Films by Plasma-irradiation and Bonding Elements
Authors: Yokura Miyoshi , Uehara Kenichi , Xiang Guo , Hanada Kazuya , Nakamura Yoshinobu , Reddy Lakshmi Sanapa , Endo Kazuhiro , Endo Tamio
Published: October 2012

Biaxially oriented polyethylene terephthalate (PET) films can be bonded directly by oxygen plasma irradiation and low temperature heat press around 100°C. The irradiated films were kept in the atmosphere for six years, yet they can be bonded tightly as well. Dry- and wet-peel tests indicate that two bonding elements can be suggested, hydrogen bonding and chemical bonding. The films are bonded by these two elements at lower temperatures, but by the pure chemical bonding at higher temperatures. FTIR results on the non-irradiated, irradiated and bonded samples indicate that OH and COOH groups are created at the surface, they are responsible for the hydrogen and chemical bondings. Dehydrated condensation reaction is proposed for the chemical bonding. It is briefly mentioned on two origins for the long lifetime of irradiated active surface.
Growth and Evaluation of [AFeOx/REFeO3] (A=Ca, Sr, RE=La, Bi) Superlattices by Pulsed Laser Deposition Method Using High Density Targets Prepared by Pechini Method
Authors: Iwata Nobuyuki , Watabe Yuta , Tsuchiya Yoshito , Norota Kento. , Hashimoto Takuya , Huijben Mark , Rijnders Guus , Blank Dave H. A. , Yamamoto Hiroshi
Published: October 2012

The LaFeO3 and CaFeOX layers are grown using highly dense target prepared by Pechini method, with which accurate growth rate is achieved. Since the LaFeO3demonstrates the obvious RHEED oscillation until the end of growth, constant growth rate, and the step-terraces structure, the LFO is employed as a buffer and/or reference layer to determine the required pulses to deposit the thickness we desire in the superlattice. Superlattices show the clear satellite peaks and Laue oscillation in the XRD spectra as well as the oscillations caused by the film thickness with a flat surface and superstructure with a flat interface in the x-ray reflection spectrum. The streaky RHEED patterns and step-terraces surface are consistent with the results of spectra using x-ray.
Nanocrystalline orientation and phase mapping of textured coatings revealed by precession electron diffraction
Authors: Mohseni H. , Collins P. C. , Scharf T. W.
Published: October 2012

Nanocrystalline orientation and phase mapping were performed to characterize texture and grain boundary tilt angles in the transmission electron microscope (TEM) using precession electron diffraction (PED). Texture analysis and grain boundary angle studies were performed on atomic layer deposition (ALD) ZnO/Al2O3/ZrO2 nanolaminate coatings. It was determined that the ZnO layer nanocolumnar grains, with random rotational orientation, exhibited fiber texture with predominately <0001> grains in the out-of-plane direction with respect to the substrate. The ZnO tilt angles were in the range of 10–20° signifying a large area fraction of predominately low angle grain boundaries. The nanolaminate coating has been shown to mitigate tribological (energetic) losses by decreasing friction and wear during sliding, hence is a potential solid lubricant material. The TEM-PED technique has future wide scale applicability in studying energy-related nanomaterial grain orientations and phases with a spatial resolution down to 1–2 nm, in which more traditional techniques, such as electron-backscatter diffraction, cannot resolve.
Temperature based validation of the analytical model for the estimation of the amount of heat generated during friction stir welding
Authors: Milcic Dragan , Mijajlovic Miroslav , Pavlovic Nenad , Vukic Mica , Mancic Dragan
Published: October 2012

Friction stir welding is a solid-state welding technique that utilizes
thermomechanical influence of the rotating welding tool on parent material
resulting in a monolith joint - weld. On the contact of welding tool and
parent material, significant stirring and deformation of parent material
appears, and during this process, mechanical energy is partially transformed
into heat. Generated heat affects the temperature of the welding tool and
parent material, thus the proposed analytical model for the estimation of the
amount of generated heat can be verified by temperature: analytically
determined heat is used for numerical estimation of the temperature of parent
material and this temperature is compared to the experimentally determined
temperature. Numerical solution is estimated using the finite difference
method - explicit scheme with adaptive grid, considering influence of
temperature on material's conductivity, contact conditions between welding
tool and parent material, material flow around welding tool, etc. The
analytical model shows that 60-100% of mechanical power given to the welding
tool is transformed into heat, while the comparison of results shows the
maximal relative difference between the analytical and experimental
temperature of about 10%.
Numerical simulation of concentrating solar collector P2CC with a small concentrating ratio
Authors: Stefanovic Velimir , Pavlovic Sasa , Ilic Marko , Apostolovic Nenad , Kustrimovic Dragan
Published: October 2012

Solar energy may be practically utilized directly through transformation into
heat, electrical or chemical energy. A physical and mathematical model is
presented, as well as a numerical procedure for predicting thermal
performances of the P2CC solar concentrator. The demonstrated prototype has
the reception angle of 110? at concentration ratio CR = 1.38, with the
significant reception of diffuse radiation. The solar collector P2CC is
designed for the area of middle temperature conversion of solar radiation
into heat. The working fluid is water with laminar flow through a copper pipe
surrounded by an evacuated glass layer. Based on the physical model, a
mathematical model is introduced, which consists of energy balance equations
for four collector components. In this paper, water temperatures in flow
directions are numerically predicted, as well as temperatures of relevant
P2CC collector components for various values of input temperatures and mass
flow rates of the working fluid, and also for various values of direct
sunlight radiation and for different collector lengths. The device which is
used to transform solar energy to heat is referred to as solar collector.
This paper gives numerical estimated changes of temperature in the direction
of fluid flow for different flow rates, different solar radiation intensity
and different inlet fluid temperatures. The increase in fluid flow reduces
output temperature, while the increase in solar radiation intensity and inlet
water temperature increases output temperature of water. Furthermore, the
dependence on fluid output temperature is determined, along with the current
efficiency by the number of nodes in the numerical calculation.
Binding of the Phage Display Derived Peptide CaIX-P1 on Human Colorectal Carcinoma Cells Correlates with the Expression of Carbonic Anhydrase IX
Authors: Askoxylakis Vasileios , Ehemann Volker , Rana Shoaib , Krämer Susanne , Rahbari Nuh N. , Debus Jürgen , Haberkorn Uwe
Published: October 2012

Phage display represents an attractive screening strategy for the identification of novel, specific binding ligands that could be used for tumor targeting. Recently, a new peptide (CaIX-P1) with affinity for human carbonic anhydrase IX (CAIX) was identified and evaluated. The aim of the present study is to characterize the properties of CaIX-P1 for targeting human colorectal carcinoma and investigate the correlation of peptide binding with the expression of carbonic anhydrase IX. Human colorectal carcinoma HCT116 and HT29 cells were investigated for CAIX expression using Western Blot analysis. Binding and competition studies of 125I-radiolabeled CaIX-P1 were performed on HCT116 cells in vitro. FACS analysis and fluorescence microscopy studies were carried out after cell incubation with fluorescein-labeled CaIX-P1 and rhodamine-labeled anti-human CAIX-mAb. Our studies revealed an enhanced in vitro expression of carbonic anhydrase IX in HCT116 and HT29 cells with increasing cell density. Binding of 125I-labeled-CaIX-P1 on HCT116 cells increased with increasing cell density and correlated to the CAIX expression. FACS analysis demonstrated a correlation of cell labeling between FITC-CaIX-P1 and rhodamine-labeled anti-CAIX-mAb in both HCT116 and HT29 cells. The results of our study indicate that the phage display identified peptide CaIX-P1 might be an attractive candidate for the development of a ligand targeting CAIX in colorectal cancer.
DNA-Directed Base Pair Opening
Authors: Timsit Youri
Published: October 2012

Strand separation is a fundamental molecular process essential for the reading of the genetic information during DNA replication, transcription and recombination. However, DNA melting in physiological conditions in which the double helix is expected to be stable represents a challenging problem. Current models propose that negative supercoiling destabilizes the double helix and promotes the spontaneous, sequence-dependent DNA melting. The present review examines an alternative view and reveals how DNA compaction may trigger the sequence dependent opening of the base pairs. This analysis shows that in DNA crystals, tight DNA-DNA interactions destabilize the double helices at various degrees, from the alteration of the base-stacking to the opening of the base-pairs. The electrostatic repulsion generated by the DNA close approach of the negatively charged sugar phosphate backbones may therefore provide a potential source of the energy required for DNA melting. These observations suggest a new molecular mechanism for the initial steps of strand separation in which the coupling of the DNA tertiary and secondary interactions both actively triggers the base pair opening and stabilizes the intermediate states during the melting pathway.