bluuebunny/crossref_metadata_2025 huggingface dataset:
Better never than late
Authors: Wilson Christo , Ballani Hitesh , Karagiannis Thomas , Rowtron Ant
Published: December 2011

The soft real-time nature of large scale web applications in today's datacenters, combined with their distributed workflow, leads to deadlines being associated with the datacenter application traffic. A network flow is useful, and contributes to application throughput and operator revenue if, and only if, it completes within its deadline. Today's transport pro- tocols (TCP included), given their Internet origins, are agnostic to such flow deadlines. Instead, they strive to share network resources fairly. We show that this can hurt application performance.

Motivated by these observations, and other (previously known) deficiencies of TCP in the datacenter environment, this paper presents the design and implementation of D3, a deadline-aware control protocol that is customized for the datacenter environment. D3 uses explicit rate control to apportion bandwidth according to flow deadlines. Evaluation from a 19-node, two-tier datacenter testbed shows that D3, even without any deadline information, easily outper- forms TCP in terms of short flow latency and burst tolerance. Further, by utilizing deadline information, D3 effectively doubles the peak load that the datacenter network cansupport.
Predicting and tracking internet path changes
Authors: Cunha Italo , Teixeira Renata , Veitch Darryl , Diot Christophe
Published: December 2011

This paper investigates to what extent it is possible to use traceroute-style probing for accurately tracking Internet path changes. When the number of paths is large, the usual traceroute based approach misses many path changes because it probes all paths equally. Based on empirical observations, we argue that monitors can optimize probing according to the likelihood of path changes. We design a simple predictor of path changes using a nearest neighbor model. Although predicting path changes is not very accurate, we show that it can be used to improve probe targeting. Our path tracking method, called DTrack, detects up to two times more path changes than traditional probing, with lower detection delay, as well as providing complete load-balancer information.
Clearing the RF smog
Authors: Gollakota Shyamnath , Adib Fadel , Katabi Dina , Seshan Srinivasan
Published: December 2011

Recent studies show that high-power cross-technology interference is becoming a major problem in today's 802.11 networks. Devices like baby monitors and cordless phones can cause a wireless LAN to lose connectivity. The existing approach for dealing with such high-power interferers makes the 802.11 network switch to a different channel; yet the ISM band is becoming increasingly crowded with diverse technologies, and hence many 802.11 access points may not find an interference-free channel.

This paper presents TIMO, a MIMO design that enables 802.11n to communicate in the presence of high-power cross-technology interference. Unlike existing MIMO designs, however, which require all concurrent transmissions to belong to the same technology, TIMO can exploit MIMO capabilities to decode in the presence of a signal from a different technology, hence enabling diverse technologies to share the same frequency band. We implement a prototype of TIMO in GNURadio-USRP2 and show that it enables 802.11n to communicate in the presence of interference from baby monitors, cordless phones, and microwave ovens, transforming scenarios with a complete loss of connectivity to operational networks.
NetQuery
Authors: Shieh Alan , Sirer Emin Gün , Schneider Fred B.
Published: December 2011

This paper presents the design and implementation of NetQuery, a knowledge plane for federated networks such as the Internet. In such networks, not all administrative domains will generate information that an application can trust and many administrative domains may have restrictive policies on disclosing network information. Thus, both the trustworthiness and accessibility of network information pose obstacles to effective reasoning. NetQuery employs trustworthy computing techniques to facilitate reasoning about the trustworthiness of information contained in the knowledge plane while preserving confidentiality guarantees for operator data. By characterizing information disclosure between operators, NetQuery enables remote verification of advertised claims and contractual stipulations; this enables new applications because network guarantees can span administrative boundaries. We have implemented NetQuery, built several NetQuery-enabled devices, and deployed applications for cloud datacenters, enterprise networks, and the Internet. Simulations, testbed experiments, and a deployment on a departmental network indicate NetQuery can support hundreds of thousands of operations per second and can thus scale to large ISPs.
Fast interprocedural linear two-variable equalities
Authors: Flexeder Andrea , Müller-olm Markus , Petter Michael , Seidl Helmut
Published: December 2011

In this article we provide an interprocedural analysis of linear two-variable equalities. The novel algorithm has a worst-case complexity of 𝒪(
n
⋅
k
4
), where
k
is the number of variables and
n
is the program size. Thus, it saves a factor of
k
4
in comparison to a related algorithm based on full linear algebra. We also indicate how the practical runtime can be further reduced significantly. The analysis can be applied, for example, for register coalescing, for identifying local variables and thus for interprocedurally observing stack pointer modifications as well as for an analysis of array index expressions, when analyzing low-level code.
Understanding CS1 students; defective software
Authors: Guzdial Mark , Meyer Bertrand
Published: December 2011

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

http://cacm.acm.org/blogs/blog-cacm

ark Guzdial writes about why teachers must grasp introductory CS students' theories about computing. Bertrand Meyer argues for the necessity of analyzing large-scale software disasters and publishing a detailed technical study.
Celebration time
Authors: Underwood Sarah
Published: December 2011

The centennial celebrations of Alan Turing's birth might help turn a quiet British genius into an iconic global hero.
The state of phishing attacks
Authors: Hong Jason
Published: December 2011

Looking past the systems people use, they target the people using the systems.
Future Tense: The near cloud
Authors: Wilson Daniel H.
Published: December 2011

Future Tense, one of the revolving features on this page, presents stories and essays from the intersection of computational science and technological speculation, their boundaries limited only by our ability to imagine what will and could be.

Wish I never pulled the plug…
Contribution of FSH and triiodothyronine to the development of circadian clocks during granulosa cell maturation
Authors: Chu Guiyan , Misawa Izumi , Chen Huatao , Yamauchi Nobuhiko , Shigeyoshi Yasufumi , Hashimoto Seiichi , Hattori Masa-aki
Published: December 2011

The involvement of FSH and triiodothyronine (T3) in circadian clocks was investigated using immature granulosa cells of ovaries during the progress of cell maturation. Granulosa cells were prepared from preantral follicles of mouse Period2 ( Per2) -dLuc reporter gene transgenic rats injected subcutaneously with the synthetic nonsteroidal estrogen diethylstilbestrol. Analysis of the cellular clock of the immature granulosa cells was performed partly using a serum-free culture system. Several bioluminescence oscillations of Per2-dLuc promoter activity were generated in the presence of FSH + fetal bovine serum, but not in the presence of either FSH or serum. As revealed by bioluminescence recording and analysis of clock gene expression, the granulosa cells lack the functional cellular clock at the immature stage, although Lhr was greatly expressed during the period of cell maturation. The granulosa cells gained a strong circadian rhythm of bioluminescence during stimulation with FSH, whereas LH reset the cellular clock of matured granulosa cells. During strong circadian rhythms of clock genes, the Star gene showed significant expression in matured granulosa cells. In contrast, T3showed an inhibitory effect on the development of the functional cellular clock during the period of cell maturation. These results indicate that FSH provides a cue for the development of the functional cellular clock of the immature granulosa cells, and T3blocks the development of the cellular clock.
A perspective on the determination of mitochondrial biogenesis
Authors: Miller Benjamin F. , Hamilton Karyn L.
Published: December 2011

The measurement of mitochondrial biogenesis is important in the determination of aging and disease processes and the assessment of countermeasurements to them. We argue that the frequently used assessments of cell signaling, mitochondrial protein mRNA, mitochondrial protein expression or enzyme activity, and mitochondrial density are not measurements that can lead to conclusions about mitochondrial biogenesis. Instead, we propose that only measurements of mitochondrial synthesis are indicative of biogenesis. Clarification of this issue will hopefully result in further differentiation of the processes important for morphological and functional changes of mitochondria.
Altered lymphatics in an ovine model of congenital heart disease with increased pulmonary blood flow
Authors: Datar Sanjeev A. , Johnson Eric G. , Oishi Peter E. , Johengen Michael , Tang Eric , Aramburo Angela , Barton Jubilee , Kuo Hsuan-Chang , Bennett Stephen , Xoinis Konstantine , Reel Bhupinder , Kalkan Gokhan , Sajti Eniko , Osorio Oscar , Raff Gary W. , Matthay Michael A. , Fineman Jeffrey R.
Published: December 2011

Abnormalities of the lymphatic circulation are well recognized in patients with congenital heart defects. However, it is not known how the associated abnormal blood flow patterns, such as increased pulmonary blood flow (PBF), might affect pulmonary lymphatic function and structure. Using well-established ovine models of acute and chronic increases in PBF, we cannulated the efferent lymphatic duct of the caudal mediastinal node and collected and analyzed lymph effluent from the lungs of lambs with acutely increased PBF ( n = 6), chronically increased PBF ( n = 6), and age-matched normal lambs ( n = 8). When normalized to PBF, we found that lymph flow was unchanged following acute increases in PBF but decreased following chronic increases in PBF. The lymph:plasma protein ratio decreased with both acute and chronic increases in PBF. Lymph bioavailable nitric oxide increased following acute increases in PBF but decreased following chronic increases in PBF. In addition, we found perturbations in the transit kinetics of contrast material through the pleural lymphatics of lambs with chronic increases in PBF. Finally, there were structural changes in the pulmonary lymphatic system in lambs with chronic increases in PBF: lymphatics from these lambs were larger and more dilated, and there were alterations in the expression of vascular endothelial growth factor-C, lymphatic vessel endothelial hyaluronan receptor-1, and Angiopoietin-2, proteins known to be important for lymphatic growth, development, and remodeling. Taken together these data suggest that chronic increases in PBF lead to both functional and structural aberrations of lung lymphatics. These findings have important therapeutic implications that warrant further study.
Modulation of cardiopulmonary depressor reflex in nucleus ambiguus by electroacupuncture: roles of opioids and γ-aminobutyric acid
Authors: Tjen-A-Looi Stephanie C. , Li Peng , Li Min , Longhurst John C.
Published: December 2011

Stimulation of cardiopulmonary receptors with phenylbiguanide (PBG) elicits depressor cardiovascular reflex responses, including decreases in blood pressure and heart rate mediated in part by the brain stem parasympathetic cardiac neurons in the nucleus ambiguus (NAmb). The present study examined NAmb neurotransmitter mechanisms underlying the influence of electroacupuncture (EA) on the PBG-induced hypotension and bradycardia. We hypothesized that somatic stimulation during EA modulates PBG responses through opioid and γ-aminobutyric acid (GABA) modulation in the NAmb. Anesthetized and ventilated cats were studied during repeated stimulation with PBG or cardiac vagal afferents while low-frequency EA (2 Hz) was applied at P5–6 acupoints overlying the median nerve for 30 min and NAmb neuronal activity, heart rate, and blood pressure were recorded. Microinjection of kainic acid into the NAmb attenuated the PBG-induced bradycardia from −60 ± 11 to −36 ± 11 beats/min. Likewise, EA reduced the PBG-induced depressor and bradycardia reflex by 52 and 61%, respectively. Cardiac vagal afferent evoked preganglionic cellular activity in the NAmb was reduced by EA for about 60 min. Blockade of opioid or GABAAreceptors using naloxone and gabazine reversed the EA-related modulation of the evoked cardiac vagal activity by 73 and 53%, respectively. Similarly, naloxone and gabazine reversed EA modulation of the negative chronotropic responses from −11 ± 5 to −23 ± 6 and −13 ± 4 to −24 ± 3 beats/min, respectively. Thus EA at P5–6 decreases PBG evoked hypotension and bradycardia as well as the NAmb PBG-sensitive preganglionic cardiac vagal outflow through opioid and GABA neurotransmitter systems.
Acute calcineurin inhibition with tacrolimus increases phosphorylated UT-A1
Authors: Ilori Titilayo O. , Wang Yanhua , Blount Mitsi A. , Martin Christopher F. , Sands Jeff M. , Klein Janet D.
Published: December 2011

UT-A1, the urea transporter present in the apical membrane of the inner medullary collecting duct, is crucial to the kidney's ability to concentrate urine. Phosphorylation of UT-A1 on serines 486 and 499 is important for plasma membrane trafficking. The effect of calcineurin on dephosphorylation of UT-A1 was investigated. Inner medullary collecting ducts from Sprague-Dawley rats were metabolically labeled and treated with tacrolimus to inhibit calcineurin or calyculin to inhibit protein phosphatases 1 and 2A. UT-A1 was immunoprecipitated, electrophoresed, blotted, and total UT-A1 phosphorylation was assessed by autoradiography. Total UT-A1 was determined by Western blotting. A phospho-specific antibody to pser486-UT-A1 was used to determine whether serine 486 can be hyperphosphorylated by inhibiting phosphatases. Inhibition of calcineurin showed an increase in phosphorylation per unit protein at serine 486. In contrast, inhibition of phosphatases 1 and 2A resulted in an increase in UT-A1 phosphorylation but no increase in pser486-UT-A1. In vitro perfusion of inner medullary collecting ducts showed tacrolimus-stimulated urea permeability consistent with stimulated urea transport. The location of phosphorylated UT-A1 in rats treated acutely and chronically with tacrolimus was determined using immunohistochemistry. Inner medullary collecting ducts of the acutely treated rats showed increased apical membrane association of phosphorylated UT-A1 while chronic treatment reduced membrane association of phosphorylated UT-A1. We conclude that UT-A1 may be dephosphorylated by multiple phosphatases and that the PKA-phosphorylated serine 486 is dephosphorylated by calcineurin. This is the first documentation of the role of phosphatases and the specific site of phosphorylation of UT-A1, in response to tacrolimus.
Induction of hemeoxygenase-1 reduces glomerular injury and apoptosis in diabetic spontaneously hypertensive rats
Authors: Elmarakby Ahmed A. , Faulkner Jessica , Baban Babak , Saleh Mohamed A. , Sullivan Jennifer C.
Published: December 2011

Induction of hemeoxygenase-1 (HO-1) lowers blood pressure and reduces organ damage in hypertensive animal models; however, a potential protective role for HO-1 induction against diabetic-induced glomerular injury remains unclear. We hypothesize that HO-1 induction will protect against diabetes-induced glomerular injury by maintaining glomerular integrity and inhibiting renal apoptosis, inflammation, and oxidative stress. Diabetes was induced with streptozotocin in spontaneously hypertensive rats (SHR) as a model where the coexistence of hypertension and diabetes aggravates the progression of diabetic renal injury. Control and diabetic SHR were randomized to receive vehicle or the HO-1 inducer cobalt protoporphyrin (CoPP). Glomerular albumin permeability was significantly greater in diabetic SHR compared with control, consistent with an increase in apoptosis and decreased glomerular nephrin and α3β1-integrin protein expression in diabetic SHR. CoPP significantly reduced albumin permeability and apoptosis and restored nephrin and α3β1-integrin protein expression levels in diabetic SHR. Glomerular injury in diabetic SHR was also associated with increases in NF-κB-induced inflammation and oxidative stress relative to vehicle-treated SHR, and CoPP significantly blunted diabetes-induced increases in glomerular inflammation and oxidative stress in diabetic SHR. These effects were specific to exogenous stimulation of HO-1, since incubation with the HO inhibitor stannous mesoporphyrin alone did not alter glomerular inflammatory markers or oxidative stress yet was able to prevent CoPP-mediated decreases in these parameters. These data suggest that induction of HO-1 reduces diabetic induced-glomerular injury and apoptosis and these effects are associated with decreased NF-κB-induced inflammation and oxidative stress.
Glial-derived adenosine modulates spinal motor networks in mice
Authors: Witts Emily C. , Panetta Kara M. , Miles Gareth B.
Published: December 2011

The activation of purinergic receptors modulates central pattern generators controlling rhythmic motor behaviors, including respiration in rodents and swimming in frog tadpoles. The present study aimed to determine whether purinergic signaling also modulates the mammalian locomotor central pattern generator. This was investigated by using isolated spinal cord preparations obtained from neonatal mice in which locomotor-related activity can be induced pharmacologically. The application of either ATP or adenosine led to a reduction in the frequency of locomotor activity recorded from ventral roots. ATP had no effect when applied in the presence of both the adenosine receptor antagonist theophylline and the ectonucleotidase inhibitor ARL67156, demonstrating that the effects of ATP application result from the breakdown of ATP to adenosine and subsequent activation of adenosine receptors. The application of theophylline or the A1-specific antagonist cyclopentyl dipropylxanthine, but not the A2A-receptor antagonist SCH58261, caused an increase in locomotor burst frequency, demonstrating that endogenously derived adenosine activates A1receptors during locomotor network activity. Furthermore, theophylline had no effect in the presence of the ectonucleotidase inhibitor ARL67156 or the glial toxins methionine sulfoximine or ethyl fluoracetate, suggesting that endogenous adenosine is derived from ATP, which is released from glia. Finally, adenosine had no effect on slow rhythmic activity recorded upon blockade of all inhibitory transmission, suggesting that adenosine may act via the modulation of inhibitory transmission. Together, these data highlight endogenous purinergic gliotransmission, involving activation of A1receptors, as an important intrinsic modulatory system controlling the frequency of activity generated by spinal locomotor circuitry in mammals.
Domain III regulates N-type (CaV2.2) calcium channel closing kinetics
Authors: Yarotskyy Viktor , Gao Guofeng , Peterson Blaise Z. , Elmslie Keith S.
Published: December 2011

CaV2.2 (N-type) and CaV1.2 (L-type) calcium channels gate differently in response to membrane depolarization, which is critical to the unique physiological functions mediated by these channels. We wondered if the source for these differences could be identified. As a first step, we examined the effect of domain exchange between N-type and L-type channels on activation-deactivation kinetics, which were significantly different between these channels. Kinetic analysis of chimeric channels revealed N-channel-like deactivation for all chimeric channels containing N-channel domain III, while activation appeared to be a more distributed function across domains. This led us to hypothesize that domain III was an important regulator of N-channel closing. This idea was further examined with R-roscovitine, which is a trisubstituted purine that slows N-channel deactivation by exclusively binding to activated N-channels. L-channels lack this response to roscovitine, which allowed us to use N-L chimeras to test the role of domain III in roscovitine modulation of N-channel deactivation. In support of our hypothesis, all chimeric channels containing the N-channel domain III responded to roscovitine with slowed deactivation, while those chimeric channels with L-channel domain III did not. Thus a combination of kinetic and pharmacological evidence supports the hypothesis that domain III is an important regulator of N-channel closing. Our results support specialization of gating functions among calcium channel domains.
Holographic Multiquarks in the Quark-Gluon Plasma: A Review
Authors: Burikham Piyabut , Hirunsirisawat Ekapong
Published: December 2011

We review the holographic multiquark states in the deconfined quark-gluon plasma. Nuclear matter can become deconfined by extremely high temperature and/or density. In the deconfined nuclear medium, bound states with colour degrees of freedom are allowed to exist. Using holographic approach, the binding energy and the screening length of the multiquarks can be calculated. Using the deconfined Sakai-Sugimoto model, the phase diagram of the multiquark phase, the vacuum phase, and the chiral-symmetric quark-gluon plasma can be obtained. Then we review the magnetic properties of the multiquarks and their phase diagrams. The multiquark phase is compared with the pure pion gradient, the magnetized vacuum, and the chiral-symmetric quark-gluon plasma phases. For moderate temperature and sufficiently large density at a fixed magnetic field, the mixed phase of multiquark and pion gradient is the most energetically preferred phase.
The Stability of Some Differential Equations
Authors: Pourpasha M. M. , Rassias Th. M. , Saadati R. , Vaezpour S. M.
Published: December 2011

We generalize the results obtained by Jun and Min (2009)
and use fixed point method to obtain the stability of the functional equation f(x + σ(y)) = F[f(x), f(y)], for a class of functions of a vector space
into a Banach space where σ is an involution. Then we obtain the stability of the differential equations of the form y′ = F[q(x), P(x)y(x)].
Some Classes of Difference Sequence Spaces of Fuzzy Real Numbers Defined by Orlicz Function
Authors: Tripathy Binod Chandra , Borgohain Stuti
Published: December 2011

We introduce the classes of generalized difference bounded, convergent, and null sequences of fuzzy real numbers defined by an Orlicz function. Some properties of these sequence spaces like solidness, symmetricity, and convergence-free are studied. We obtain some inclusion relations involving these sequence spaces.
Approach to the Pretransplant Evaluation of the Living Kidney Donor
Authors: Sachdeva Mala , Bhaskaran Madhu , Molmenti Ernesto P. , Dalton Donna , Mattana Joseph
Published: December 2011

Evaluation of the potential kidney donor is a complex activity that differs substantially from other types of preoperative assessments. The well being of the donor, who derives no medical benefit from this surgery, must be assured in both the short term and long term, and the potential adverse consequences to the recipient must be determined as well. The criteria that must be met for a person to donate a kidney are rigorous and include medical, social, psychosocial, ethical, and legal issues. Donor evaluation can be divided into assessments to protect the health and safety of the donor and assessments to protect the health and safety of the recipient. This article provides an approach to evaluating a donor, focusing on the complex issues that an evaluator is faced with. A careful assessment of risks and benefits to both the donor and recipient can lead to favorable outcomes.
Second‐Order Optimality Conditions for Set‐Valued Optimization Problems Under Benson Proper Efficiency
Authors: Wang Qilin , Yu Guolin
Published: December 2011

Some new properties are obtained for generalized second‐order contingent (adjacent) epiderivatives of set‐valued maps. By employing the generalized second‐order adjacent epiderivatives, necessary and sufficient conditions of Benson proper efficient solutions are given for set‐valued optimization problems. The results obtained improve the corresponding results in the literature.
Regulatory T Cells and Parasites
Authors: Velavan TP. , Ojurongbe Olusola
Published: December 2011

Human host encounters a wide array of parasites; however, the crucial aspect is the failure of the host immune system to clear these parasites despite antigen recognition. In the recent past, a new immunological concept has emerged, which provides a framework to better understand several aspects of host susceptibility to parasitic infection. It is widely believed that parasites are able to modulate the magnitude of effector responses by inducing regulatory T cell (Tregs) population and several studies have investigated whether this cell population plays a role in balancing protective immunity and pathogenesis during parasite infection. This review discusses the several mechanism of Treg‐mediated immunosuppression in the human host and focuses on the functional role of Tregs and regulatory gene polymorphisms in infectious diseases.
Photo-Oxidation of Rhodamine-6-G via TiO2and Au/TiO2-Bound Polythene Beads
Authors: Elfeky Souad A. , Al-Sherbini Al-Sayed A.
Published: December 2011

It is very important to improve the efficiency of water detoxification techniques. In this study, TiO2or gold-TiO2(Au/TiO2) nanocomposite-bound polythene beads were used for the photo-oxidation of rhodamine 6G (R6G) as a model of water organic pollutants. Simple thermal procedures were employed for anchoring TiO2or Au/TiO2nanocomposites to polythene beads. The results revealed that the synthesized Au/TiO2composites exhibited both considerably higher absorption capability of organic pollutants and better photocatalytic activity for the photo-oxidation of R-6G than pure titania. The better photocatalytic activity of the synthesized Au/TiO2composites film than that of the pure titania film was attributed to high capacity of light absorption intensity and easy diffusion of absorbed pollutants on the absorption sites to photogenerated oxidizing radicals on the photoactive sites.
Dye-Sensitized Nanocrystalline ZnO Solar Cells Based on Ruthenium(II) Phendione Complexes
Authors: Shahroosvand Hashem , Abbasi Parisa , Ameri Mohsen , Riahi Dehkordi Mohammad Reza
Published: December 2011

The metal complexes ( (phen)2(phendione))(PF6)2(1), [ (phen)(bpy)(phendione))(PF6)2(2), and ( (bpy)2(phendione))(PF6)2(3) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine and phendione = 1,10-phenanthroline-5,6-dione) have been synthesized as photo sensitizers for ZnO semiconductor in solar cells. FT-IR and absorption spectra showed the favorable interfacial binding between the dye-molecules and ZnO surface. The surface analysis and size of adsorbed dye on nanostructure ZnO were further examined with AFM and SEM. The AFM images clearly show both, the outgrowth of the complexes which are adsorbed on ZnO thin film and the depression of ZnO thin film. We have studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phendione complexes, which gave power conversion efficiency of (η) of 1.54% under the standard AM 1.5 irradiation (100 mW cm−2) with a short-circuit photocurrent density () of 3.42 mA cm−2, an open-circuit photovoltage () of 0.622 V, and a fill factor (ff) of 0.72. Monochromatic incident photon to current conversion efficiency was 38% at 485 nm.
Positive Solutions of Nonlinear Eigenvalue Problems for a Nonlocal Fractional Differential Equation
Authors: Han Xiaoling , Gao Hongliang
Published: December 2011

By using the fixed point theorem, positive solutions of nonlinear eigenvalue problems for a nonlocal fractional differential equation are considered, where 1 < α ≤ 2 is a real number, λ is a positive parameter, is the standard Riemann‐Liouville differentiation, and ξi ∈ (0,1), αi ∈ [0, ∞) with , a(t) ∈ C([0,1], [0, ∞)),   f(t, u) ∈ C([0, ∞), [0, ∞)).
Mechanochemical Synthesis and Rapid Consolidation of Nanocrystalline 3NiAl-Al2O3Composites
Authors: Shon In-Jin , Ko In-Yong , Jo Seung-Hoon , Doh Jung-Mann , Yoon Jin-Kook , Park Sang-Whan
Published: December 2011

Nanopowders of 3NiAl and Al2O3were synthesized from 3NiO and 5Al powders by high-energy ball milling. Nanocrystalline Al2O3reinforced composite was consolidated by high-frequency induction-heated sintering within 3 minutes from mechanochemically synthesized powders of Al2O3and 3NiAl. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. The relative density of the composite was 97%. The average Vickers hardness and fracture toughness values obtained were 804 kg/mm2and 7.5 MPa⋅m1/2, respectively.
Some Remarks on End-Nim
Authors: Cairns Grant , Ho Nhan Bao
Published: December 2011

We reexamine Albert and Nowakowski's variation on
the game of Nim, called End-Nim, in which the players may only
remove coins from the leftmost or rightmost piles. We reformulate
Albert and Nowakowski's solution to this game. We examine its
misère version and a further variant where the winner is the player
who reduces the game to a single pile; we call this Loop-End-Nim.
We show that the three games, End-Nim, misère-End-Nim, and
Loop-End-Nim, all have the same losing positions, except for the
positions where all the piles are of equal size. We also give some
partial results concerning the higher Sprague-Grundy values of the
three games.
Clinical Outcome of Laparoscopic Intersphincteric Resection Combined with Transanal Rectal Dissection for T3 Low Rectal Cancer in Patients with a Narrow Pelvis
Authors: Funahashi Kimihiko , Shiokawa Hiroyuki , Teramoto Tatsuo , Koike Junichi , Kaneko Hironori
Published: December 2011

Purpose. The purpose of this study was to analyze the safety and feasibility of laparoscopic intersphincteric resection (ISR) combined with transanal rectal dissection (TARD) for T3 low rectal cancer in a narrow pelvis.Methods. We studied 20 patients with a narrow pelvis of median body mass index 25.3 (16.9–31.2). Median observation period was 23.6 months (range 12.2–56.7).Results. Partial, subtotal, and total ISR was performed in 15, 1, and 4 patients, respectively. Median duration of TARD was 83 min (range 43–135). There were no major complications perioperatively or postoperatively. Surgical margins were histologically free of tumor cells in all patients, and there was no local recurrence. Excluding urgency, frequency of bowel movements, and incontinence status improved gradually after stoma closure.Conclusion. Laparoscopic ISR combined with TARD is technically feasible for selective T3 low rectal cancer in patients with a narrow pelvis.
Association of Duration of Sleep and Cardiovascular and Metabolic Comorbidities in Sleep Apnea Syndrome
Authors: Ucar Zeynep Zeren , Cirak Ali Kadri , Olcay Serhan , Uysal Hatice , Demir Ahmet Ugur , Özacar Rıfat
Published: December 2011

Background/Aim. Previous population-based studies found association between duration of sleep and cardiovascular and metabolic comorbidities. Our aim was to investigate the association between the duration of sleep and cardiovascular and metabolic comorbidities in OSAS.Patients and Methods. The study enrolled 312 patients, who had polysomnography (PSG) during 2006-2007 and responded to a telephone-administered questionnaire providing information on characteristics of sleep on average 12 months after PSG.Results. Of the patients, 90 were female (28.8%), 173 (58.5) received the diagnosis of OSAS, 150 (45%) had no comorbidities, 122 had hypertension (HT), 44 had diabetes mellitus (DM), and 38 had coronary heart disease (CHD). Mean ± SD of age in years was47.2±10.6,56.5±9.3,53.2±8.9, and59.9±9.0for the no comorbidity, HT, DM, and CHD groups, respectively. Reported duration of sleep was not associated with any of the comorbidities in the overall group. In the analysis restricted to OSAS patients, sleep duration ≤6 hours was significantly associated with CHD after the adjustment for age, gender, and other associated factors (OR: 5.8, 95% CI: 1.0–32.6).Conclusions. Confirmation of the association between shorter duration of sleep and CHD will provide prognostic information and help for the management of OSAS.
Silicon Oxynitride Optical Waveguide Ring Resonator Utilizing a Two-Mode Interferometer Structure
Authors: Chen Kaixin , Chan Hau Ping
Published: December 2011

Silicon oxynitride (SiOxNy, SiON) optical waveguide ring resonator, in which a two-mode interferometer is used to replace the directional coupler in a conventional ring resonator, has been designed and fabricated. Preliminary results exhibit the same of free spectral range of 100 GHz but different quality factors of 3700 and 3900 at 1550 nm for transverse electric (TE) and transverse magnetic (TM) mode, respectively. The extinction ratio is more than 18 dB over the entire C-band, and the insertion loss is lower than 9.5 dB for TE and TM mode.
Solving Linear Coupled Fractional Differential Equations by Direct Operational Method and Some Applications
Authors: Lim S. C. , Eab Chai Hok , Mak K. H. , Li Ming , Chen S. Y.
Published: December 2011

A new direct operational inversion method is introduced for solving coupled linear systems of ordinary fractional differential equations. The solutions so‐obtained can be expressed explicitly in terms of multivariate Mittag‐Leffler functions. In the case where the multiorders are multiples of a common real positive number, the solutions can be reduced to linear combinations of Mittag‐Leffler functions of a single variable. The solutions can be shown to be asymptotically oscillatory under certain conditions. This technique is illustrated in detail by two concrete examples, namely, the coupled harmonic oscillator and the fractional Wien bridge circuit. Stability conditions and simulations of the corresponding solutions are given.
Multiple Approaches for Individualized Fertility Protective Therapy in Cancer Patients
Authors: Demeestere I. , Moffa F. , Peccatori F. , Poirot C. , Shalom-Paz E.
Published: December 2011

In the last decade, fertility preservation has risen as a major field of interest, creating new interactions between oncologists and gynecologists. Various options, such as cryopreservation of ovarian tissue, have been developed and are currently routinely proposed in many centers. However, many of the options remain experimental and should be offered to patients only after adequate counseling. This paper addresses the efficiency and the potential of the different fertility preservation approaches.
Peroxisome Proliferator–Activated Receptors Modulate Proliferation and Angiogenesis in Human Endometrial Carcinoma
Authors: Nickkho-Amiry Mahshid , McVey Rhona , Holland Cathrine
Published: December 2011

Peroxisome proliferator-activated receptors (PPAR) and retinoid X receptors (RXR) are implicated in the development of several obesity-related cancers. Little is known of either the expression or function of PPARs and RXRs in endometrial cancer although this increasingly common disease is highly associated with both obesity and insulin resistance. We investigated the expression of PPAR and RXR subtypes in human endometrial cancers and normal endometrium with immunoblotting and immunohistochemistry and subsequently showed PPAR/RXR binding preferences by coimmunoprecipitation. To determine the functions of PPARs within the endometrium, we investigated proliferation, apoptosis, PTEN expression, and secretion of vascular endothelial growth factor (VEGF) in endometrial cell lines after reducing the expression of PPARα and PPARγ with antisense RNA. The functional effects of PPAR ligands were also investigated in vitro. We identified differential expression of PPAR and RXR subtypes in endometrial cancers and discovered that PPARγ expression correlated with expression of PTEN. PPARα activation influences endometrial cell growth and VEGF secretion. PPARγ activation reduces proliferation of endometrial cells via regulation of PTEN and appears to reduce VEGF secretion. We conclude that the PPAR/RXR pathway contribute to endometrial carcinogenesis by control of PTEN expression and modulation of VEGF secretion. We propose that PPAR ligands should be considered for clinical investigation in early phase studies of women with endometrial cancer. Mol Cancer Res; 10(3); 441–53. ©2011 AACR.
9-cis Retinoic Acid Inhibits Inflammatory Responses of Adherent Monocytes and Increases Their Ability to Induce Classical Monocyte Migration
Authors: Kolseth Ingrid B.M. , Ågren Joanna , Sundvold-Gjerstad Vibeke , Lyngstadaas Staale P. , Wang Jacob E. , Dahle Maria K.
Published: December 2011

Patients with vitamin A/retinol deficiency are shown to be prone to infections and to suffer from increased inflammation, effects which can be remedied by vitamin A supplements. We aimed to study how human monocytes from the peripheral venous blood of healthy donors acted within the initial hours after adherence and exposure to bacterial endotoxin in the presence or absence of the 9-cis-isomer of retinoic acid (9cisRA). We found that adherent human monocytes were dominated by the CD14dimCD16+ subtype. Pretreatment with 9cisRA for 1 h significantly decreased lipopolysaccharide (LPS)-induced mRNA expression and protein release of tumor necrosis factor (TNF)α, interleukin (IL)-6 and chemokine ligands (CCL)3 and CCL4. In contrast, treatment with 9cisRA rapidly enhanced the production of monocyte chemoattractive protein/CCL2. 9cisRA treatment also led to enhanced migration of classical CD14high monocytes in a transwell in vitro system. We conclude that 9cisRA treatment of human adherent monocytes attenuates the inflammatory responses to LPS and induces the attraction of classical monocytes, a feature which may help explain why supplements administered to vitamin A-deficient patients counteract inflammation and increases the ability to fight infections.
Increased Presence of Cognitive Impairment in Hemodialysis Patients in the Absence of Neurological Events
Authors: Post James B. , Morin Kel G. , Sano Mary , Jegede Adejoke B. , Langhoff Erik , Spungen Ann M.
Published: December 2011

Background/Aims: Cognitive impairment (CI) is highly prevalent among hemodialysis (HD) patients and is associated with increased morbidity and mortality. The aim was to compare cognitive function in HD patients with no history of stroke or dementia and well-matched controls. Studies are required to determine the impact of HD and chronic kidney disease-specific risks on CI. Methods: 76 outpatients (50 receiving outpatient HD and 26 with normal kidney function matched for age and comorbidity) underwent a cross-sectional observational study. HD patients were well dialyzed and had optimal hemoglobin levels. A battery of eight neuropsychological tests was used. Outcomes included assessment scores of neurocognitive testing and prevalence and subtype of CI. Results: Compared to controls, HD subjects had significantly lower composite scores for each tested cognitive domain. In each domain except memory, the percentage of subjects with impairment was significantly higher in HD subjects than controls. Differences between the groups were independent of vascular and dementia risk factors. 82% of HD subjects met criteria for CI versus 50% of controls. Non-amnestic subtype of CI was more prevalent in both groups. Conclusion: Well-dialyzed HD patients with optimized hemoglobin levels and with no history of stroke or dementia performed significantly worse on multiple measures of cognition compared to controls. A higher prevalence of non-memory impairment may suggest an underlying vascular versus neurodegenerative mechanism. HD and chronic kidney disease-specific risk factors may contribute to early CI not readily detected by routine screening methods.
Ischemic Cerebral Damage
Authors: Hofmeijer Jeannette , van Putten Michel J.A.M.
Published: December 2011

In the human brain, ≈30% of the energy is spent on synaptic transmission. Disappearance of synaptic activity is the earliest consequence of cerebral ischemia. The changes of synaptic function are generally assumed to be reversible and persistent damage is associated with membrane failure and neuronal death. However, there is overwhelming experimental evidence of isolated, but persistent, synaptic failure resulting from mild or moderate cerebral ischemia. Early failure results from presynaptic damage with impaired transmitter release. Proposed mechanisms include dysfunction of adenosine triphosphate-dependent calcium channels and a disturbed docking of glutamate-containing vesicles resulting from impaired phosphorylation. We review energy distribution among neuronal functions, focusing on energy usage of synaptic transmission. We summarize the effect of ischemia on neurotransmission and the evidence of long-lasting synaptic failure as a cause of persistent symptoms in patients with cerebral ischemia. Finally, we discuss the implications of synaptic failure in the diagnosis of cerebral ischemia, including the limited sensitivity of diffusion-weighted MRI in those cases in which damage is presumably limited to the synapses.
Greek Alchemists at Work: 'Alchemical Laboratory' in the Greco-Roman Egypt
Authors: Martelli Matteo
Published: December 2011

The paper focuses on the alchemical laboratory of ancient Greco-Egyptian alchemists, by taking into account especially the earliest alchemical texts (both in the Greek and in the Syriac tradition), ascribed to Pseudo-Democritus, Maria the Jewish and Zosimus. The first part analyzes the possible relationships between the workshops of Egyptian craftsmen (first of all, dyers, metals workers and glass workers) and the activity of the alchemists. The second part gives a general overview on the alchemical instruments described in the Corpus alchemicum.
Evaluation of Radar Precipitation Estimates from the National Mosaic and Multisensor Quantitative Precipitation Estimation System and the WSR-88D Precipitation Processing System over the Conterminous United States
Authors: Wu Wanru , Kitzmiller David , Wu Shaorong
Published: December 2011

This study evaluated 24-, 6-, and 1-h radar precipitation estimated from the National Mosaic and Multisensor Quantitative Precipitation Estimation System (NMQ) and the Weather Surveillance Radar-1988 Doppler (WSR-88D) Precipitation Processing System (PPS) over the conterminous United States (CONUS) for the warm season April–September 2009 and the cool season October 2009–March 2010. Precipitation gauge observations from the Automated Surface Observing System (ASOS) were used as the ground truth. Gridded StageIV multisensor precipitation estimates were applied for supplementary verification. The comparison of the two systems consisted of a series of analyses including the linear correlation coefficient (CC) and the root-mean-square error (RMSE) between the radar precipitation estimates and the gauge observations, large precipitation amount detection categorical scores, and the reliability of precipitation amount distribution. Data stratified for the 12 CONUS River Forecast Centers (RFCs) and for the cold rains events with bright-band effects were analyzed additionally. Major results are 1) the linear CC of NMQ versus ASOS are generally higher than that of PPS versus ASOS over CONUS, while the spatial variations stratified by the RFCs may switch with seasons; 2) compared to the precipitation distribution of ASOS, NMQ shows less deviation than PPS; 3) for the cold rains verified against ASOS, NMQ has higher CC and PPS has lower RMSE for 6-h and higher RMSE for 1-h cold rains; and 4) for the precipitation detection categorical scores, either NMQ or PPS can be superior, depending on the time interval and season. The verification against StageIV gridded precipitation estimates showed that NMQ consistently had higher correlations and lower biases than did PPS.
Investigating Invariant Item Ordering in Personality and Clinical Scales
Authors: Meijer Rob R. , Egberink Iris J. L.
Published: December 2011

In recent studies, different methods were proposed to investigate invariant item ordering (IIO), but practical IIO research is an unexploited field in questionnaire construction and evaluation. In the present study, the authors explored the usefulness of different IIO methods to analyze personality scales and clinical scales. From the authors’ analyses, it was clear that for clinical scales consisting of items that cover a limited range of “symptoms,” the IIO property is an unrealistic assumption. For scales that consist of items that cover a broader range of item severity, IIO research can provide useful information. However, removing an item because it violates the assumption of IIO may be problematic because it can affect the construct that is measured. Finally, the authors advise researchers to always use plots of item rest-score regressions to interpret IIO results.
Relations Among Student Attention Behaviors, Teacher Practices, and Beginning Word Reading Skill
Authors: Sáez Leilani , Folsom Jessica Sidler , Al Otaiba Stephanie , Schatschneider Christopher
Published: December 2011

The role of student attention for predicting kindergarten word reading was investigated among 432 students. Using Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Rating Scale behavior rating scores, the authors conducted an exploratory factor analysis, which yielded three distinct factors that reflected selective attention. In this study, the authors focused on the role of one of these factors, which they labeled attention-memory, for predicting reading performance. Teacher ratings of attention-memory predicted word reading above and beyond the contribution of phonological awareness and vocabulary knowledge. In addition, the relations between four teacher practices and attention ratings for predicting reading performance were examined. Using hierarchical linear modeling, the authors found significant interactions between student attention and teacher practices observed during literacy instruction. In general, as ratings of attention improved, better kindergarten word reading performance was associated with high levels of classroom behavior management. However, better word reading performance was not associated with high levels of teacher task orienting. A significant three-way interaction was also found among attention, individualized instruction, and teacher task redirections. The role of regulating kindergarten student attention to support beginning word reading skill development is discussed.
Market Entry in the Presence of Network Effects
Authors: Chintakananda Asda , McIntyre David P.
Published: December 2011

This research holds that extant theory on real options has several limitations with regard to strategic initiatives in markets influenced by network effects. In addressing these limitations, the authors argue that markets with strong network effects tend to enhance both growth and deferral options. Furthermore, the extent to which growth and deferral options affect market entry in these settings is conditioned by both the strength of network effects (i.e., network intensity) and the presence of a dominant design in the market. Implications for real options theory in the context of network effects and for firms considering entry into markets influenced by network effects are offered and discussed.