bluuebunny/crossref_metadata_2025 huggingface dataset:
First passage times and option pricing under a mixed-exponential jump diffusion model (abstract only)
Authors: Kou Steven S.G.
Published: April 2012

This paper aims at extending the analytical tractability of the Black- Scholes model to alternative models with arbitrary jump size distributions. More precisely, we propose a jump diffusion model for asset prices whose jump sizes have a mixed-exponential distribution, which is a weighted average of exponential distributions but with possibly negative weights. The new model extends existing models, such as hyper-exponential and double-exponential jump diffusion models, as the mixed-exponential distribution can approximate
any
distribution as closely as possible, including the normal distribution and various heavy-tailed distributions. The mixedexponential jump diffusion model can lead to analytical solutions for Laplace transforms of prices and sensitivity parameters for pathdependent options such as lookback and barrier options. The Laplace transforms can be inverted via the Euler inversion algorithm. Numerical experiments indicate that the formulae are easy to implement and accurate. The analytical solutions are made possible mainly because we solve a high-order integro-differential equation related to first passage times explicitly. A calibratrion example for SPY options shows that the model can provide a reasonable fit even for options with very short maturiy, such as one day. This is a joint work with Ning Cai at Hong Kong Univ. of Science and Technology.
Analysis of the dynamics of social queues by quasi-birth-and-death processes (abstract only)
Authors: Toyoizumi Hiroshi , Field Jeremy
Published: April 2012

A wide variety of animals are known to form simple hierarchical groups called social queues, where individuals inherit resources or social status in a predictable order. Queues are often age-based, so that a new individual joins the end of the queue on reaching adulthood, and must wait for older individuals to die in order to reach the front of the queue. While waiting, an individual may work for her group, in the process often risking her own survival and hence her chance of inheritance. Eventually, she may survive to reach the head of the queue and becomes the dominant of the group.

Queueing has been particularly well-studied in hover wasps (Hymenoptera: Stenogastrinae). In hover wasp social groups, only one female lays eggs, and there is a strict, age-based queue to inherit the reproductive position. While the dominant individual (queen) concentrates on breeding, subordinate helpers risk death by foraging outside the nest, but have a slim chance of eventually inheriting dominance. Some explanations for this altruistic behavior and for the stability of social queues have been proposed and analyzed [1, 2]. Since both the productivity of the nest and the chance to inherit the dominant position depend critically on group size, queueing dynamics are crucial for understanding social queues, but detailed analysis is lacking.

Here, using hover wasps as an example, we demonstrate that the application of Little's formula [3] and quasi-birth-and-death (QBD) processes are useful for analyzing queueing dynamics and the population demographics of social queues. Let (L(t),M(t)) be the number of adults and brood (eggs, larvae and pupae) in a nest at time t. We model the vector (L(t),M(t)) as a QBD process starting from the state (L(0),M(0)) = (1, 0) to analyze the nest history of a social queue. The boundary state {L(t) = 0}, which corresponds to the termination of the nest, is regarded as the taboo state of this QBD process. Let
Q
be the transition rate matrix of the taboo process. By choosing different
Q
, we can set various conditions for the social queue. By using standard technique such as calculating
Q
?1, we can estimate and compare the productivity of the nest in wide variety of social queues in different queueing and environmental conditions.

Our work leads to better understanding of how environmental conditions and strategic decision-making by individuals interact to produce the observed group dynamics; and in turn, how group dynamics affects individual decision-making.
A compressed cyclic reduction for QBDs with low rank upper and lower transitions
Authors: Bini Dario A. , Favati Paola , Meini Beatrice
Published: April 2012

Consider a quasi-birth-and-death (QBD) Markov chain [6], having probability transition matrix where Bi, Ai, i = ?1, 0, 1, are m x m matrices. In the numerical solution of QBD Markov chains a crucial step is the efficient computation of the minimal nonnegative solution R of the quadratic matrix equation X = X
2
A?1 + XA
0
+ A
1
. (1) To this purpose, many numerical methods, with different properties, have been designed in the last years (see for instance [1, 2, 3, 4]). However, many of these numericalmethods are defined for general block coefficients A?1, A0 and A1, and do not exploit the possible structure of these blocks.

Recently, some attention has been addressed to the case where A
?1
has only few non-null columns, or A1 has only few non-null rows. These properties are satisfied when the QBD has restricted transitions to higher (or lower) levels. In particular, in [7] the authors exploit these properties of the matrix A
?1
, or A
1
, to formulate the QBD in terms of an M/G/1 type Markov chain, where the block matrices have size smaller than m; in particular, when both A?1 and A1 have the desired property, the latter M/G/1 type Markov chain reduces to a QBD. In [5] the structure of A
?1
is used in order to reduce the computational cost of some algorithms for computing R.

Here we assume that both the matrices A
?1
and A
1
have small rank with respect to their size m. In particular, if A?1 and A1 have only few non-null columns and rows, respectively, they have small rank. We show that, under this assumption, the matrix R can be computed by using the cyclic reduction algorithm, where the matrices A(k) i , i = ?1, 0, 1, generated at the kth step of the algorithm, can be represented by small rank matrices. In particular, if r
?1
is the rank of A
?1
, and if r
1
is the rank of A
1
, then each step of cyclic reduction can be performed by means of O((r
?1+r1
)
3
) arithmetic operations. This cost estimate must be compared with the cost of O(m3) arithmetic operations, needed without exploiting the structure of A
?1
and A
1
. Therefore, if r
1
and r
1
/are much smaller than m, the advantage is evident.

It remains an open issue to understand how the structure can be exploited in the case where only one between A
?1
and A
1
has low rank.
Stationary distribution of a perturbed QBD process
Authors: Dendievel S. , Latouche G. , Remiche M-A.
Published: April 2012

We consider Quasi-Birth-and-Death processes and our purpose is to assess the impact of small variation of the initial parameters.
Admission control policies for a multi-class QoS-aware service oriented architecture
Authors: Abundo Marco , Cardellini Valeria , Lo Presti Francesco
Published: April 2012

In the service computing paradigm, a service broker can build new applications by composing network-accessible services offered by loosely coupled independent providers. In this paper, we address the problem of providing a service broker, which offers to prospective users a composite service with a range of different Quality of Service (QoS) classes, with a forward-looking admission control policy based on Markov Decision Processes (MDP). This mechanism allows the broker to decide whether to accept or reject a new potential user in such a way to maximize its gain while guaranteeing non-functional QoS requirements to its already admitted users. We model the broker using a continuous-time MDP and consider various techniques suitable to solve both infinite-horizon and finitehorizon MDPs. To assess the effectiveness of the MDP-based admission control for the service broker, we present simulation results where we compare the optimal decisions obtained by the analytical solution of the MDP with other admission control policies. To deal with large problem instances, we also propose a heuristic policy for the MDP solution.
Bringing architecture back to computing
Authors: Denning Peter J.
Published: April 2012

Over the past 10 or 20 years, the subject of machine organization and system architecture has been deemphasized in favor of the powerful abstractions that support computational thinking. We have grown accustomed to slogans like "computing is bits, not atoms"---suggesting that bits are not physical and the properties of the physical world are less and less important for understanding computation.
A novel location privacy framework without trusted third party based on location anonymity prediction
Authors: Ahamed Sheikh Iqbal , Haque Md. Munirul , Hasan Chowdhury Sharif
Published: April 2012

Location-based services are becoming increasingly popular with the proliferation of location aware devices. It is not possible to access location-based services and preserve privacy at the same time when the user provides exact location information. Cloaking or obfuscating location data is the only way to protect location-privacy. To do that, most of the systems use third party location anonymizer. In this paper, we propose a novel location privacy framework without any trusted third party (TTP). Most of the existing solutions attempt to satisfy k-anonymity. However, there are several drawbacks of using fixed and user defined k. In order to solve the problems our proposed solution aims to meet probabilistic k-anonymity. Based on historic data expected number of users present in a place is predicted which is used as probabilistic anonymity level. Thus we eliminate the use of any TTP which results into improvement of query-processing time and provides fewer query results for the user to process eventually minimizing the overall response time. Users' exact location information is not revealed in either communication or computation process.
Highlights from IWGS 2011: the 2nd ACM SIGSPATIAL International Workshop on GeoStreaming
Authors: Ali Mohamed , Hoel Erik , Banaei-Kashani Farnoush
Published: April 2012

The ACM SIGSPATIAL International Workshop on Geostreaming (IWGS) was held for the second time in conjunction with the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS 2011). The workshop has been a successful event that attracted participants from both academia and industry. The workshop addressed topics that are at the intersection of data streaming and geospatial systems. The workshop fostered an environment where geospatial researchers can benefit from the advances in geosensing technologies and data streaming systems.
A case for unlimited watchpoints
Authors: Greathouse Joseph L. , Xin Hongyi , Luo Yixin , Austin Todd
Published: April 2012

Numerous tools have been proposed to help developers fix software errors and inefficiencies. Widely-used techniques such as memory checking suffer from overheads that limit their use to pre-deployment testing, while more advanced systems have such severe performance impacts that they may require special-purpose hardware. Previous works have described hardware that can accelerate individual analyses, but such specialization stymies adoption; generalized mechanisms are more likely to be added to commercial processors. This paper demonstrates that the ability to set an unlimited number of fine-grain data watchpoints can reduce the runtime overheads of numerous dynamic software analysis techniques. We detail the watchpoint capabilities required to accelerate these analyses while remaining general enough to be useful in the future. We describe a hardware design that stores watchpoints in main memory and utilizes two different on-chip caches to accelerate performance. The first is a bitmap lookaside buffer that stores fine-grained watchpoints, while the second is a range cache that can efficiently hold large contiguous regions of watchpoints. As an example of the power of such a system, it is possible to use watchpoints to accelerate read/write set checks in a software data race detector by nearly 9x.
Whole-system persistence
Authors: Narayanan Dushyanth , Hodson Orion
Published: April 2012

Today's databases and key-value stores commonly keep all their data in main memory. A single server can have over 100 GB of memory, and a cluster of such servers can have 10s to 100s of TB. However, a storage back end is still required for recovery from failures. Recovery can last for minutes for a single server or hours for a whole cluster, causing heavy load on the back end. Non-volatile main memory (NVRAM) technologies can help by allowing near-instantaneous recovery of in-memory state. However, today's software does not support this well. Block-based approaches such as persistent buffer caches suffer from data duplication and block transfer overheads. Recently, user-level persistent heaps have been shown to have much better performance than these. However they require substantial application modification and still have significant runtime overheads. This paper proposes whole-system persistence (WSP) as an alternative. WSP is aimed at systems where all memory is non-volatile. It transparently recovers an application's entire state, making a failure appear as a suspend/resume event. Runtime overheads are eliminated by using "flush on fail": transient state in processor registers and caches is flushed to NVRAM only on failure, using the residual energy from the system power supply. Our evaluation shows that this approach has 1.6--13 times better runtime performance than a persistent heap, and that flush-on-fail can complete safely within 2--35\% of the residual energy window provided by standard power supplies.
ELI
Authors: Gordon Abel , Amit Nadav , Har'El Nadav , Ben-Yehuda Muli , Landau Alex , Schuster Assaf , Tsafrir Dan
Published: April 2012

Direct device assignment enhances the performance of guest virtual machines by allowing them to communicate with I/O devices without host involvement. But even with device assignment, guests are still unable to approach bare-metal performance, because the host intercepts all interrupts, including those interrupts generated by assigned devices to signal to guests the completion of their I/O requests. The host involvement induces multiple unwarranted guest/host context switches, which significantly hamper the performance of I/O intensive workloads. To solve this problem, we present ELI (ExitLess Interrupts), a software-only approach for handling interrupts within guest virtual machines directly and securely. By removing the host from the interrupt handling path, ELI manages to improve the throughput and latency of unmodified, untrusted guests by 1.3x-1.6x, allowing them to reach 97%-100% of bare-metal performance even for the most demanding I/O-intensive workloads.
A Rotor Flux and Speed Observer for Sensorless Single-Phase Induction Motor Applications
Authors: Caruso Massimo , Cecconi Vittorio , Di Tommaso Antonino O. , Rocha Ronilson
Published: April 2012

It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring the development of efficient alternatives to improve the operational performance of this machine. Although the rotor flux and rotational speed are essential variables in order to optimize the operation of a SPIM, the use of conventional sensors to measure them is not a viable option. Thus, the adoption of sensorless strategies is the more reasonable proposal for these cases. This paper presents a rotor flux and rotational speed observer for sensorless applications involving SPIMs. Computer simulations and the experimental results are used to verify the performance of the proposed observer.
Proteasome Inhibition Blocks NF-κB and ERK1/2 Pathways, Restores Antigen Expression, and Sensitizes Resistant Human Melanoma to TCR-Engineered CTLs
Authors: Jazirehi Ali R. , Economou James S.
Published: April 2012

Adoptive cell transfer (ACT) of ex vivo engineered autologous lymphocytes encoding high-affinity MART-1/HLA-A*0201–specific T-cell receptor (TCR)α/β chains (F5 CTL), densely infiltrate into sites of metastatic disease, mediating dramatic but partial clinical responses in patients with melanoma. We hypothesized that MART-1 downmodulation in addition to aberrant apoptotic/survival signaling could confer resistance to death signals delivered by transgenic CTLs. To explore this hypothesis, we established an in vitro model of resistant (R) lines from MART-1+/HLA-A*0201+ F5 CTL–sensitive parental (P) lines under serial F5 CTL–selective pressure. We have recently reported that several melanoma R lines, while retaining MART-1 expression, exhibited constitutive NF-κB activation and overexpression of NF-κB–dependent resistance factors. Another established melanoma cell line M244, otherwise sensitive to F5 CTL, yielded R lines after serial F5 CTL–selective pressure, which had both reduced MART-1 expression levels, thus, could not be recognized, and were resistant to CTL-delivered apoptotic death signals. The proteasome inhibitor bortezomib blocked NF-κB activity, decreased phospho-ERK1/2, increased phospho-c-jun–NH2–kinase (p-JNK) levels, reduced expression of resistance factors, restored MART-1 expression to sufficient levels, which in combination allowed M244R lines be sensitized to F5 CTL killing. These findings suggest that proteasome inhibition in immune resistant tumors can restore proapoptotic signaling and improve tumor antigen expression. Mol Cancer Ther; 11(6); 1332–41. ©2012 AACR.
Estrogen Receptors and the Regulation of Neural Stress Responses
Authors: Handa Robert J. , Mani Shaila K. , Uht Rosalie M.
Published: April 2012

It is now well established that estrogens can influence a panoply of physiological and behavioral functions. In many instances, the effects of estrogens are mediated by the ‘classical’ actions of two different estrogen receptors (ERs), ERα or ERβ. ERα and ERβ appear to have opposing actions in the control of stress responses and modulate different neurotransmitter or neuropeptide systems. Studies elucidating the molecular mechanisms for such regulatory processes are currently in progress. Furthermore, the use of ERα and ERβ knockout mouse lines has allowed the exploration of the importance of these receptors in behavioral responses such as anxiety-like and depressive-like behaviors. This review examines some of the recent advances in our knowledge of hormonal control of neuroendocrine and behavioral responses to stress and underscore the importance of these receptors as future therapeutic targets for control of stress-related signaling pathways.
Inter-rater reliability of the Nottingham Neurological Driving Assessment for people with dementia – a preliminary evaluation
Authors: Lincoln NB , Taylor J , Radford KA
Published: April 2012

Objective:

The purpose was to examine the inter-rater reliability of the Nottingham Neurological Driving Assessment.

Participants:

Six drivers with dementia (mean age 78 years, 5 men).

Interventions:

Participants were assessed for their safety to drive on a set route while being observed by two driving assessors, who were experienced in assessing safety to drive in people with dementia.

Main measures:

Performance was rated in terms of overall safety to drive and 25 items were recorded as correct, minor error (not compromising safety) and major error (compromising safety).

Results:

Four drivers were found to be probably safe to drive and two definitely unsafe to drive. There was perfect agreement in the overall decisions about safety to drive. There were significant discrepancies between correct or minor error and major error on six of the 25 items of the road test involving three participants.

Conclusions:

Two experienced driving assessors agreed on the overall safety to drive of six participants with dementia. There were discrepancies about safety on six out of 150 observations (4%).
Synthesis and characterization of ZnS:Mn/ZnS core/shell nanoparticles for tumor targeting and imaging in vivo
Authors: Yu Zhangsen , Ma Xiying , Yu Bin , Pan Yuefang , Liu Zhaogang
Published: April 2012

Fluorescence imaging technique has been used for imaging of biological cells and tissues in vivo. The Cd-free luminescent quantum dots conjugating with a cancer targeting ligand has been taken as a promising biocompatibility and low cytotoxicity system for targeted cancer imaging. This work reports the synthesis of fluorescent-doped core/shell quantum dots of water-soluble manganese-doped zinc sulfide. Quantum dots of manganese-doped zinc sulfide were prepared by nucleation doping strategy, with 3-mercaptopropionic acid as stabilizer at 90℃ in aqueous solution. The manganese-doped zinc sulfide nanoparticles exhibit strong orange fluorescence under UV irradiation, resistance to photo-bleaching, and low-cytotoxicity to HeLa cells. The structure and optical properties of nanoparticles were characterized by scanning electron microscope, X-ray diffraction, dynamic light scattering, and photoluminescence emission spectroscopy. Manganese-doped zinc sulfide nanoparticles conjugated with folic acid using 2,2′-(ethylenedioxy)-bis-(ethylamine) as the linker. The covalent binding of both 2,2′-(ethylenedioxy)-bis-(ethylamine) and folic acid on the surface of manganese-doped zinc sulfide nanoparticles probed by Fourier transform infrared spectroscopy detection. Furthermore, in vitro cytotoxicity assessment of manganese-doped zinc sulfide–folic acid probes use HeLa cells. The obtained fluorescent probes (manganese-doped zinc sulfide) were used for tumor targeting and imaging in vivo. The manganese-doped zinc sulfide–folic acid fluorescent probes which targeting the tumor cells in the body of nude mouse tumor model would emit orange fluorescence, when exposed to a 365 nm lamp. We investigate the biodistribution of the manganese-doped zinc sulfide–folic acid fluorescent probes in tumor mouse model by measuring zinc concentration in tissues. These studies demonstrate the practicality of manganese-doped zinc sulfide–folic acid fluorescent probes as promising platform for tumor targeting and imaging in vivo.
Developing Transactive Memory Systems
Authors: Liao Jenny , Jimmieson Nerina L. , O’Brien Anne T. , Restubog Simon L. D.
Published: April 2012

Transactive memory system (TMS) theory explains how expertise is recognized and coordinated in teams. Extending current TMS research from a group information-processing perspective, our article presents a theoretical model that considers TMS development from a social identity perspective. We discuss how two features of communication (quantity and quality) important to TMS development are linked to TMS through the group identification mechanism of a shared common team identity. Informed by social identity theory, we also differentiate between intragroup and intergroup contexts and outline how, in multidisciplinary teams, professional identification and perceived equality of status among professional subgroups have a role to play in TMS development. We provide a theoretical discussion of future research directions aimed at testing and extending our model.
Genome-wide host responses against infectious laryngotracheitis virus vaccine infection in chicken embryo lung cells
Authors: Lee Jeongyoon , Bottje Walter G , Kong Byung-Whi
Published: April 2012

Background

Infectious laryngotracheitis virus (ILTV; gallid herpesvirus 1) infection causes high mortality and huge economic losses in the poultry industry. To protect chickens against ILTV infection, chicken-embryo origin (CEO) and tissue-culture origin (TCO) vaccines have been used. However, the transmission of vaccine ILTV from vaccinated- to unvaccinated chickens can cause severe respiratory disease. Previously, host cell responses against virulent ILTV infections were determined by microarray analysis. In this study, a microarray analysis was performed to understand host-vaccine ILTV interactions at the host gene transcription level.

Results

The 44 K chicken oligo microarrays were used, and the results were compared to those found in virulent ILTV infection. Total RNAs extracted from vaccine ILTV infected chicken embryo lung cells at 1, 2, 3 and 4 days post infection (dpi), compared to 0 dpi, were subjected to microarray assay using the two color hybridization method. Data analysis using JMP Genomics 5.0 and the Ingenuity Pathway Analysis (IPA) program showed that 213 differentially expressed genes could be grouped into a number of functional categories including tissue development, cellular growth and proliferation, cellular movement, and inflammatory responses. Moreover, 10 possible gene networks were created by the IPA program to show intermolecular connections. Interestingly, of 213 differentially expressed genes, BMP2, C8orf79, F10, and NPY were expressed distinctly in vaccine ILTV infection when compared to virulent ILTV infection.

Conclusions

Comprehensive knowledge of gene expression and biological functionalities of host factors during vaccine ILTV infection can provide insight into host cellular defense mechanisms compared to those of virulent ILTV.
Identification and expression analysis of methyl jasmonate responsive ESTs in paclitaxel producing Taxus cuspidata suspension culture cells
Authors: Lenka Sangram K , Boutaoui Nadia , Paulose Bibin , Vongpaseuth Kham , Normanly Jennifer , Roberts Susan C , Walker Elsbeth L
Published: April 2012

Background

Taxol® (paclitaxel) promotes microtubule assembly and stabilization and therefore is a potent chemotherapeutic agent against wide range of cancers. Methyl jasmonate (MJ) elicited Taxus cell cultures provide a sustainable option to meet the growing market demand for paclitaxel. Despite its increasing pharmaceutical importance, the molecular genetics of paclitaxel biosynthesis is not fully elucidated. This study focuses on identification of MJ responsive transcripts in cultured Taxus cells using PCR-based suppression subtractive hybridization (SSH) to identify genes involved in global pathway control.

Results

Six separate SSH cDNA libraries of paclitaxel-accumulating Taxus cuspidata P991 cell lines were constructed at three different post-elicitation time points (6h, 18h and 5 day) to identify genes that are either induced or suppressed in response to MJ. Sequencing of 576 differentially screened clones from the SSH libraries resulted in 331 unigenes. Functional annotation and Gene Ontology (GO) analysis of up-regulated EST libraries showed enrichment of several known paclitaxel biosynthetic genes and novel transcripts that may be involved in MJ-signaling, taxane transport, or taxane degradation. Macroarray analysis of these identified genes unravelled global regulatory expression of these transcripts. Semi-quantitative RT-PCR analysis of a set of 12 candidate genes further confirmed the MJ-induced gene expression in a high paclitaxel accumulating Taxus cuspidata P93AF cell line.

Conclusions

This study elucidates the global temporal expression kinetics of MJ responsive genes in Taxus suspension cell culture. Functional characterization of the novel genes identified in this study will further enhance the understanding of paclitaxel biosynthesis, taxane transport and degradation.
Lidocaine Patch (5%) is No More Potent than Placebo in Treating Chronic Back Pain When Tested in a Randomised Double Blind Placebo Controlled Brain Imaging Study
Authors: Hashmi Javeria A , Baliki Marwan N , Huang Lejian , Parks Elle L , Chanda Mona L , Schnitzer Thomas , Apkarian A Vania
Published: April 2012

Background:

The 5% Lidocaine patch is used for treating chronic neuropathic pain conditions such as chronic back pain (CBP), diabetic neuropathy and complex regional pain syndrome, but is effective in a variable proportion of patients. Our lab has reported that this treatment reduces CBP intensity and associated brain activations when tested in an open labelled preliminary study. Notably, effectiveness of the 5% Lidocaine patch has not been tested against placebo for treating CBP. In this study, effectiveness of the 5% Lidocaine patch was compared with placebo in 30 CBP patients in a randomised double-blind study where 15 patients received 5% Lidocaine patches and the remaining patients received placebo patches. Functional MRI was used to identify brain activity for fluctuations of spontaneous pain, at baseline and at two time points after start of treatment (6 hours and 2 weeks).

Results:

There was no significant difference between the treatment groups in either pain intensity, sensory and affective qualities of pain or in pain related brain activation at any time point. However, 50% patients in both the Lidocaine and placebo arms reported a greater than 50% decrease in pain suggesting a marked placebo effect. When tested against an untreated CBP group at similar time points, the patch treated subjects showed significantly greater decrease in pain compared to the untreated group (n = 15).

Conclusions:

These findings suggest that although the 5% Lidocaine is not better than placebo in its effectiveness for treating pain, the patch itself induces a potent placebo effect in a significant proportion of CBP patients.
The Emergence of Adolescent Onset Pain Hypersensitivity following Neonatal Nerve Injury
Authors: Vega-Avelaira David , McKelvey Rebecca , Hathway Gareth , Fitzgerald Maria
Published: April 2012

Background:

Peripheral nerve injuries can trigger neuropathic pain in adults but cause little or no pain when they are sustained in infancy or early childhood. This is confirmed in rodent models where neonatal nerve injury causes no pain behaviour. However, delayed pain can arise in man some considerable time after nerve damage and to examine this following early life nerve injury we have carried out a longer term follow up of rat pain behaviour into adolescence and adulthood.

Results:

Spared nerve injury (SNI) or sham surgery was performed on 10 day old (P10) rat pups and mechanical nociceptive reflex thresholds were analysed 3, 7, 14, 21, 28, 38 and 44 days post surgery. While mechanical thresholds on the ipsilateral side are not significantly different from controls for the first 2–3 weeks post P10 surgery, after that time period, beginning at 21 days post surgery (P31), the SNI group developed following early life nerve injury significant hypersensitivity compared to the other groups. Ipsilateral mechanical nociceptive threshold was 2-fold below that of the contralateral and sham thresholds at 21 days post surgery (SNI-ipsilateral 28 (±5) g control groups 69 (±9) g, p<0.001, 3-way ANOVA, n = 6 per group). Importantly, no effect was observed on thermal thresholds. This hypersensivity was accompanied by macrophage, microglial and astrocyte activation in the DRG and dorsal horn, but no significant change in dorsal horn p38 or JNK expression. Preemptive minocycline (daily 40 mg/kg, s.c) did not prevent the effect. Ketamine (20 mg/kg, s.c), on the other hand, produced a dose-dependent reversal of mechanical nociceptive thresholds ipsilateral to the nerve injury such that thresholds return to control levels at the highest doses of 20 mg/Kg.

Conclusions:

We report a novel consequence of early life nerve injury whereby mechanical hypersensitivity only emerges later in life. This delayed adolescent onset in mechanical pain thresholds is accompanied by neuroimmune activation and NMDA dependent central sensitization of spinal nociceptive circuits. This delayed onset in mechanical pain sensitivity may provide clues to understand the long term effects of early injury such as late onset phantom pain and the emergence of complex adolescent chronic pain syndromes.
A multicenter study confirms CD226gene association with systemic sclerosis-related pulmonary fibrosis
Authors: Bossini-Castillo Lara , Simeon Carmen P , Beretta Lorenzo , Broen Jasper C , Vonk Madelon C , Ríos-Fernández Raquel , Espinosa Gerard , Carreira Patricia , Camps María T , Castillo Maria J , González-Gay Miguel A , Beltrán Emma , Carmen Freire María del , Narváez Javier , Tolosa Carlos , Witte Torsten , Kreuter Alexander , Schuerwegh Annemie J , Hoffmann-Vold Anna-Maria , Hesselstrand Roger , Lunardi Claudio , van Laar Jacob M , Chee Meng May , Herrick Ariane , Koeleman Bobby PC , Denton Christopher P , Fonseca Carmen , Radstake Timothy RDJ , Martin Javier ,   the Spanish Scleroderma Group
Published: April 2012

Introduction

CD226 genetic variants have been associated with a number of autoimmune diseases and recently with systemic sclerosis (SSc). The aim of this study was to test the influence of CD226 loci in SSc susceptibility, clinical phenotypes and autoantibody status in a large multicenter European population.

Methods

A total of seven European populations of Caucasian ancestry were included, comprising 2,131 patients with SSc and 3,966 healthy controls. Three CD226 single nucleotide polymorphisms (SNPs), rs763361, rs3479968 and rs727088, were genotyped using Taqman 5'allelic discrimination assays.

Results

Pooled analyses showed no evidence of association of the three SNPs, neither with the global disease nor with the analyzed subphenotypes. However, haplotype block analysis revealed a significant association for the TCG haplotype (SNP order: rs763361, rs34794968, rs727088) with lung fibrosis positive patients (PBonf = 3.18E-02 OR 1.27 (1.05 to 1.54)).

Conclusion

Our data suggest that the tested genetic variants do not individually influence SSc susceptibility but a CD226 three-variant haplotype is related with genetic predisposition to SSc-related pulmonary fibrosis.
Early vascular deficits are correlated with delayed mammary tumorigenesis in the MMTV-PyMT transgenic mouse following genetic ablation of the NG2 proteoglycan
Authors: Gibby Krissa , You Weon-Kyoo , Kadoya Kuniko , Helgadottir Hildur , Young Lawrence JT , Ellies Lesley G , Chang Yunchao , Cardiff Robert D , Stallcup William B
Published: April 2012

Introduction

The neuron-glial antigen 2 (NG2) proteoglycan promotes pericyte recruitment and mediates pericyte interaction with endothelial cells. In the absence of NG2, blood vessel development is negatively impacted in several pathological models. Our goal in this study was to determine the effect of NG2 ablation on the early development and function of blood vessels in mammary tumors in the mammary tumor virus-driven polyoma middle T (MMTV-PyMT) transgenic mouse, and to correlate these vascular changes with alterations in mammary tumor growth.

Methods

Three different tumor paradigms (spontaneous tumors, transplanted tumors, and orthotopic allografts of tumor cell lines) were used to investigate the effects of NG2 ablation on breast cancer progression in the MMTV-PyMT transgenic mouse. In addition to examining effects of NG2 ablation on mammary tumor growth, we also investigated effects on the structure and function of tumor vasculature.

Results

Ablation of NG2 led to reduced early progression of spontaneous, transplanted, and orthotopic allograft mammary tumors. NG2 was not expressed by the mammary tumor cells themselves, but instead was found on three components of the tumor stroma. Microvascular pericytes, myeloid cells, and adipocytes were NG2-positive in both mouse and human mammary tumor stroma. The effect of NG2 on tumor progression therefore must be stromal in nature. Ablation of NG2 had several negative effects on early development of the mammary tumor vasculature. In the absence of NG2, pericyte ensheathment of endothelial cells was reduced, along with reduced pericyte maturation, reduced sprouting of endothelial cells, reduced assembly of the vascular basal lamina, and reduced tumor vessel diameter. These early deficits in vessel structure are accompanied by increased vessel leakiness, increased tumor hypoxia, and decreased tumor growth. NG2 ablation also diminishes the number of tumor-associated and TEK tyrosine kinase endothelial (Tie2) expressing macrophages in mammary tumors, providing another possible mechanism for reducing tumor vascularization and growth.

Conclusions

These results emphasize the importance of NG2 in mediating pericyte/endothelial cell communication that is required for proper vessel maturation and function. In the absence of normal pericyte/endothelial cell interaction, poor vascular function results in diminished early progression of mammary tumors.
Induction Chemotherapy and Dose Intensification of the Radiation Boost in Locally Advanced Anal Canal Carcinoma: Final Analysis of the Randomized UNICANCER ACCORD 03 Trial
Authors: Peiffert Didier , Tournier-Rangeard Laetitia , Gérard Jean-Pierre , Lemanski Claire , François Eric , Giovannini Marc , Cvitkovic Frédérique , Mirabel Xavier , Bouché Olivier , Luporsi Elisabeth , Conroy Thierry , Montoto-Grillot Christine , Mornex Françoise , Lusinchi Antoine , Hannoun-Lévi Jean-Michel , Seitz Jean-François , Adenis Antoine , Hennequin Christophe , Denis Bernard , Ducreux Michel
Published: April 2012

Purpose

Concomitant radiochemotherapy (RCT) is the standard for locally advanced anal canal carcinoma (LAACC). Questions regarding the role of induction chemotherapy (ICT) and a higher radiation dose in LAACC are pending. Our trial was designed to determine whether dose escalation of the radiation boost or two cycles of ICT before concomitant RCT lead to an improvement in colostomy-free survival (CFS).

Patients and Methods

Patients with tumors ≥ 40 mm, or < 40 mm and N1-3M0 were randomly assigned to one of four treatment arms: (A) two ICT cycles (fluorouracil 800 mg/m2/d intravenous [IV] infusion, days 1 through 4 and 29 to 32; and cisplatin 80 mg/m2 IV, on days 1 and 29), RCT (45 Gy in 25 fractions over 5 weeks, fluorouracil and cisplatin during weeks 1 and 5), and standard-dose boost (SD; 15 Gy); (B) two ICT cycles, RCT, and high-dose boost (HD; 20-25 Gy); (C): RCT and SD boost (reference arm); and (D) RCT and HD boost.

Results

Two hundred eighty-three of 307 patients achieved full treatment. With a median follow-up period of 50 months, the 5-year CFS rates were 69.6%, 82.4%, 77.1%, and 72.7% in arms A, B, C, and D, respectively. Considering the 2 × 2 factorial analysis, the 5-year CFS was 76.5% versus 75.0% (P = .37) in groups A and B versus C and D, respectively (ICT effect), and 73.7% versus 77.8% in groups A and C versus B and D, respectively (RT-dose effect; P = .067).

Conclusion

Using CFS as our main end point, we did not find an advantage for either ICT or HD radiation boost in LAACC. Nevertheless, the results of the most treatment-intense arm B should prompt the design of further intensification studies.
Optimization of Chiral Resolution of (+/-)-1-Phenylethanol by Statistical Methods
Authors: Yadav Ganapati D. , Sontakke Jyoti B.
Published: April 2012

Optically active 1-phenylethanol is used as a chiral building block and synthetic intermediate in pharmaceutical and fine-chemical industries. Lipase - catalyzed kinetic resolution of (R,S)-1-phenylethanol with vinyl acetate as an acyl donor and Candida antarctica immobilized lipase as a biocatalyst in a batch reactor was optimized using Response Surface Methodology (RSM). Four-factor-five-level central composite rotatable design (CCRD) was employed to evaluate the effect of synthesis parameters such as speed of agitation, enzyme loading, temperature and acyl donor/alcohol molar ratio, on conversion, enantiomeric excess (ee), enantioselectivity and initial rate. Optimum reaction conditions obtained were; mole ratio of acyl donor: ester of 2:1, temperature of 42.5 °C, catalyst loading of 1.6x10-3 g.cm-3 and speed of agitation of 336 rpm. Analysis of variance was performed to determine significantly affecting variables and interactions between the process parameters.
Heads Up! A Calculation- & Jargon-Free Approach to Statistics
Authors: Giese Alan R.
Published: April 2012

Evaluating the strength of evidence in noisy data is a critical step in scientific thinking that typically relies on statistics. Students without statistical training will benefit from heuristic models that highlight the logic of statistical analysis. The likelihood associated with various coin-tossing outcomes gives students such a model. There is a point at which a majority of students will doubt the underlying fairness of a coin-tossing game, and that student-generated cutoff can be used as a critical value in a nonparametric analysis of paired data. Following this approach, student lab reports come to more closely model scientific thinking.
An Antique Microscope Slide Brings the Thrill of Discovery into a Contemporary Biology Classroom
Authors: Reiser Frank
Published: April 2012

The discovery of a Victorian-era microscope slide titled “Grouped Flower Seeds” began an investigation into the scientific and historical background of the antique slide to develop its usefulness as a multidisciplinary tool for PowerPoint presentations usable in contemporary biology classrooms, particularly large-enrollment sections. The resultant presentation was intended to engage students in discussing historical and contemporary biology education, as well as some of the intricacies of seed biology. Comparisons between the usefulness and scope of various seed identification resources, both online and in print, were made.
Make way for the ‘next generation’: application and prospects for genome-wide, epigenome-specific technologies in endocrine research
Authors: Emes Richard D , Farrell William E
Published: April 2012

Epigenetic changes, which target DNA and associated histones, can be described as a pivotal mechanism of interaction between genes and the environment. The field of epigenomics aims to detect and interpret epigenetic modifications at the whole genome level. These approaches have the potential to increase resolution of epigenetic changes to the single base level in multiple disease states or across a population of individuals. Identification and comparison of the epigenomic landscape has challenged our understanding of the regulation of phenotype. Additionally, inclusion of these marks as biomarkers in the early detection or progression monitoring of disease is providing novel avenues for future biomedical research. Cells of the endocrine organs, which include pituitary, thyroid, thymus, pancreas ovary and testes, have been shown to be susceptible to epigenetic alteration, leading to both local and systemic changes often resulting in life-threatening metabolic disease. As with other cell types and populations, endocrine cells are susceptible to tumour development, which in turn may have resulted from aberration of epigenetic control. Techniques including high-throughput sequencing and array-based analysis to investigate these changes have rapidly emerged and are continually evolving. Here, we present a review of these methods and their promise to influence our studies on the epigenome for endocrine research and perhaps to uncover novel therapeutic options in disease states.
Excessive Blinking and Ataxia in a Child With Occult Neuroblastoma and Voltage-Gated Potassium Channel Antibodies
Authors: Allen Nicholas M. , McKeon Andrew , O’Rourke Declan J. , O’Meara Anne , King Mary D.
Published: April 2012

A previously healthy 9-year-old girl presented with a 10-day history of slowly progressive unsteadiness, slurred speech, and behavior change. On examination there was cerebellar ataxia and dysarthria, excessive blinking, subtle perioral myoclonus, and labile mood. The finding of oligoclonal bands in the cerebrospinal fluid prompted paraneoplastic serological evaluation and search for an occult neural crest tumor. Antineuronal nuclear autoantibody type 1 (anti-Hu) and voltage-gated potassium channel complex antibodies were detected in serum. Metaiodobenzylguanidine scan and computed tomography scan of the abdomen showed a localized abdominal mass in the region of the porta hepatis. A diagnosis of occult neuroblastoma was made. Resection of the stage 1 neuroblastoma and treatment with pulsed corticosteroids resulted in resolution of all symptoms and signs. Excessive blinking has rarely been described with neuroblastoma, and, when it is not an isolated finding, it may be a useful clue to this paraneoplastic syndrome. Although voltage-gated potassium channel complex autoimmunity has not been described previously in the setting of neuroblastoma, it is associated with a spectrum of paraneoplastic neurologic manifestations in adults, including peripheral nerve hyperexcitability disorders.
Mediações entre conceitos, conhecimento e políticas de alimentação, nutrição e segurança alimentar e nutricional
Authors: Burlandy Luciene , Bocca Cláudia , Mattos Ruben Araujo de
Published: April 2012

Este trabalho se baseia em revisão da literatura internacional sobre abordagens conceituais relacionadas às políticas de alimentação e nutrição e de segurança alimentar e nutricional, como food policy; nutrition policy e food regimes. Propõe-se a reconhecer as relações entre os conceitos, os arranjos institucionais do Estado e a ação política em cada abordagem no contexto internacional. Adotou-se a perspectiva de que uma proposta conceitual não nasce do ponto de vista apenas do conhecimento, mas da ação política dos atores envolvidos, sendo reinventada e ressignificada em cada contexto histórico e geopolítico. Assim, carrega consigo uma intenção política, sendo resultante de projetos permanentemente em disputa, orientando e se modificando em função do que é considerado o objeto de cada política, as tentativas de resposta frente aos problemas e os arranjos institucionais necessários. Destaca-se a visão de que a construção do conhecimento transborda a contribuição acadêmica, envolvendo diferentes atores e grupos de interesse e, ao mesmo tempo, sinaliza a produção de conhecimento como militância política. Aponta, ainda, uma reflexão sobre o processo histórico de construção das abordagens conceituais e as respectivas inflexões no modo de se conceber uma política. Desta forma, os modos de explicar os fenômenos relacionados à alimentação e nutrição ou à segurança alimentar e nutricional se modificaram ao longo do tempo e revelam arranjos institucionais distintos, mais ou menos intersetoriais, ancorados em visões distintas de como tratar o problema em questão.
Cu-Al-Zn system: Calculation of thermodynamic properties in liquid phase
Authors: Gomidzelovic Lidija , Mihajlovic Ivan , Kostov Ana , Zivkovic Dragana
Published: April 2012

In the paper are presented the results of thermodynamic analysis of Cu-Al-Zn
ternary system, which belongs to a group of copper-based shape memory
materials. General solution model was used for calculation of thermodynamic
properties in the temperature interval from 1373 to 2173 K, in sections from
Cu, Al and Zn corner, respectively, with following ratios of 1:3, 1:1 and
3:1. Also, on the basis of the obtained results, ternary interaction
parameters were determined using Mathematical Modeling System (MLAB).
Polyoxometalates catalysts in the oxidation of cyclooctane by hydrogen peroxide
Authors: Trakarnpruk Wimonrat , Wannatem Apiwat , Kongpeth Jutatip
Published: April 2012

A Keggin-type tungstocobaltate, [Co(2,2'- bipy)3]2H2[CoW12O40]?9.5H2O
([Co]CoW) and tetrabutylammonium salt of vanadium-substituted
tungstophosphates [(n-C4H9)4N]4[PVW11O40], [(n-C4H9)4N]5[PV2W10O40] (PVW,
PV2W) were used as catalyst for oxidation of cyclooctane with H2O2 as oxidant
in acetonitrile. The activity of [(n-C4H9)4N4H[PCo(H2O)W11O39]?2H2O (PCoW)
was also compared. The products of the reaction were cyclooctanone,
cyclooctanol and cyclooctyl hydroperoxide. The experimental results showed
that at H2O2/cyclooctane molar ratio = 3 at 80?C, in 9 h the [Co]CoW yielded
higher conversion and selectivity to cyclooctanone. The V-based catalysts are
more active than the Co-based tungstophosphate. The PV2W gave rise to high
selectivity to cyclooctyl hydroperoxide. Cyclooctane conversion was increased
by increasing reaction time or H2O2/cyclooctane molar ratio. In the presence
of tungstocobaltate catalyst, 88% cyclooctane conversion and 82% selectivity
of cyclooctanone were obtained after 12 h using H2O2/cyclooctane molar ratio
of 9. This catalyst is stable upon treatment with H2O2. Experiments with
radical traps suggest the involvement of a free-radical mechanism.