bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of strain rate and temperature on necking transition in a polydomain smectic main chain elastomer
Authors: Lentz Daniel M. , Chen Huipeng , Yu Ziniu , Patil Harshad P. , Crane Charles A. , Hedden Ronald C.
Published: February 2011

Smectic main‐chain liquid crystalline elastomers (MCLCE) with polydomain morphology are rare examples of elastomers that can form a neck and undergo cold drawing under tension. However, not all previous studies of the mechanical behavior of smectic MCLCE reported neck formation. The mechanical response of a polydomain smectic MCLCE has therefore been characterized by elongation at varying strain rates and temperatures to identify factors favoring mechanical instability. Yielding and neck formation are increasingly favored as the strain rate increases at constant temperature, or as the temperature decreases toward Tg. As cold drawing proceeds, significant creep occurs continuously within the neck, in contrast to the behavior of certain linear polymers that exhibit a “natural” draw ratio. Thermal imaging during elongation indicates that viscous heating is not a prerequisite for neck formation. Rather, inherent softening of the material during yielding due to morphological changes leads to an enhanced rate of deformation and contraction at the neck. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Examining the links between perceived impact of breast cancer and psychosocial adjustment: the buffering role of posttraumatic growth
Authors: Silva Sónia Martins , Moreira Helena Cruz , Canavarro Maria Cristina
Published: February 2011

Objectives: Finding positive changes in the aftermath of breast cancer (BC) may protect women against impaired adjustment. This study examines posttraumatic growth (PTG) in a sample of women receiving treatment for BC and explores the buffering role of PTG on the links between perceived impact of BC and emotional distress and quality of life (QoL).

Methods: Seventy‐eight women receiving chemotherapy (n = 57) or radiotherapy (n = 21) completed the Portuguese versions of the Posttraumatic Growth Inventory, the Hospital Anxiety and Depression Scale, the World Health Organization for QoL‐Bref and Consequences sub‐scale of the Brief Illness Perception Questionnaire (assessing perceived impact of BC).

Results: PTG was frequently reported and co‐existed with distress and dysfunction. A more negative perception of the impact of BC was significantly associated with higher emotional distress and impaired Physical and Psychological QoL, but was unrelated to PTG. Hierarchical regression analyses showed that PTG moderated these relationships, acting as a stress‐buffering mechanism. Among women who perceived BC as having a more negative impact on their lives, higher levels of PTG buffered this negative perceived impact on Psychological and Social QoL (p<0.01) and also on Depression (p<0.06). This effect was not found for Physical QoL and Anxiety.

Conclusions: Results provide support for the stress‐buffering role of PTG. Finding positive changes in cancer experience seems to protect women from the effects of a negative perception of the impact of BC on adjustment. Psychosocial intervention programs should facilitate PTG in order to promote women's adjustment. Copyright © 2011 John Wiley & Sons, Ltd.
The factor structure of the revised Illness Perception Questionnaire in a population of oesophageal cancer survivors
Authors: Dempster Martin , McCorry Noleen K.
Published: February 2011

Objectives: To determine whether the proposed seven‐factor structure of the Illness Perception Questionnaire—Revised (Timeline Acute/Chronic, Timeline Cyclical, Consequences, Personal Control, Treatment Control, Illness Coherence and Emotional Representations) is appropriate among a population of oesophageal cancer survivors.

Methods: Everyone registered with the Oesophageal Patients' Association in the UK (n = 2185) was mailed a questionnaire booklet, which included the Illness Perception Questionnaire—Revised. Responses from 587 oesophageal cancer survivors (27%) were subjected to a confirmatory factor analysis.

Results: The proposed seven‐factor structure provided a reasonable fit of the data. Modification indices suggested that a significantly better fit could be provided if one of the items on the Timeline Acute/Chronic factor loaded on the Treatment Control factor and an error covariance was added between two other items on the Timeline Acute/Chronic factor.

Conclusions: The model fit for the seven‐factor structure proposed by Moss‐Morris et al. (Psychol Health 2002;17:1–16) was found to be adequate in our study. However, the structure of the timeline acute/chronic factor needs to be considered, particularly when the IPQ‐R is to be used among older people with a potentially life‐threatening illness or those receiving palliative care. Copyright © 2011 John Wiley & Sons, Ltd.
Distribution of the lymphatic vessels in the prostatic fascia
Authors: Soga Hideo , Takenaka Atsushi , Murakami Gen , Haraguchi Takahiro , Miyake Hideaki , Tanaka Kazushi , Fujisawa Masato
Published: February 2011

BACKGROUND

The prostatic fascia‐preserving procedure is effective for the early recovery of erectile function after radical prostatectomy; however, the long‐term influence of on cancer control was unknown. This study clarified the distribution of lymphatic vessels in the prostatic fascia.

MATERIAL AND METHODS

The lymphatic vessels were analyzed in 10 prostates obtained from fixed Japanese cadavers (aged, 71–90 years old). Specimens were taken from the apex, the middle part, and the base of the right‐hand side of the prostate. Lymphatic vessels were detected by immunohistochemical stain using an antibody specific for the lymphatic endothelial cells (clone D2‐40). The lymphatic vessels were counted in the prostate capsule and the prostatic fascia of each section by light microscopy at low power (100×).

RESULTS

The median number of lymphatic vessels in the prostatic capsule per prostatic half was 21.0, 14.0, and 21.0 in the apex, middle, and base part of the prostate, respectively. In the prostatic facia the median number of lymphatic vessels per prostatic half was 8.0, 3.0, and 13.0 in the apex, middle, and the base part of the prostate, respectively. In the apex and the middle part the lymphatic vessels in the prostatic fascia were fewer than those in the prostatic capsule. However, in the base part the number of lymphatic vessels in the prostatic fascia was similar to that in the prostatic capsule.

CONCLUSIONS

The present study suggested the surgeon to pay more attention for the dissection of the fascia at the base of the prostate. Prostate 71:1294–1298, 2011. © 2011 Wiley‐Liss, Inc.
Androgen receptor regulates expression of the MUC1‐C oncoprotein in human prostate cancer cells
Authors: Rajabi Hasan , Joshi Maya Datt , Jin Caining , Ahmad Rehan , Kufe Donald
Published: February 2011

BACKGROUND

The MUC1 heterodimeric oncoprotein is aberrantly overexpressed in human prostate cancers with more aggressive pathologic and clinical features. However, the signals that regulate MUC1 expression in prostate cancer cells are not well understood.

METHODS

MUC1 expression was studied in androgen‐dependent and ‐independent prostate cancer cell lines by quantitative RT‐PCR, immunoblotting and assessment of MUC1 promoter activation. Chromatin immunoprecipitation (ChIP) studies were performed to assess androgen receptor (AR) occupancy on the MUC1 promoter. Post‐transcriptional regulation of MUC1 expression was assessed by miR‐125b‐mediated effects on activity of the MUC1 3′ untranslated region (3′UTR).

RESULTS

The present studies demonstrate that AR occupies a consensus AR element on the MUC1 promoter in androgen‐dependent LNCaP, but not in androgen‐independent DU145 and PC3, prostate cancer cells. The results further show that AR downregulates MUC1 gene transcription. Stable introduction of exogenous AR in PC3 (PC3/AR) cells and then silencing of AR confirmed AR‐mediated repression of the MUC1 promoter. AR signaling has also been shown to drive miR‐125b expression. The present studies further demonstrate that miR‐125b suppresses MUC1 translation in LNCaP cells and that an anti‐sense miR‐125b upregulates expression of MUC1 protein. In addition, stable expression of miR‐125b in DU145 cells resulted in decreases in MUC1 levels.

CONCLUSIONS

These findings demonstrate that AR signaling regulates MUC1 expression by transcriptional and posttranscriptional mechanisms in prostate cancer cells. Prostate 71:1299–1308, 2011. © 2011 Wiley‐Liss, Inc.
G‐protein alpha‐s and ‐12 subunits are involved in androgen‐stimulated PI3K activation and androgen receptor transactivation in prostate cancer cells
Authors: Liu Jianjun , Youn Hyewon , Yang Jun , Du Ningchao , Liu Jihong , Liu Hongwei , Li Benyi
Published: February 2011

BACKGROUND

The androgen receptor (AR) is a ligand‐dependent transcription factor that mediates androgenic hormone action in cells. We recently demonstrated the involvement of phosphoinositide 3‐OH kinase (PI3K) p110beta in AR transactivation and gene expression. In this study, we determined the upstream signals that lead to PI3K/p110beta activation and AR transactivation after androgen stimulation.

METHODS

Human prostate cancer LAPC‐4 and 22Rv1 cell lines were used for the experiments. AR transactivation was assessed using an androgen responsive element‐driven luciferase (ARE‐LUC) assay. Cell proliferation was examined using BrdU incorporation and MTT assays. Target genes were silenced using small interfering RNA (siRNA) approach. Gene expression was evaluated at the mRNA level (real‐time RT‐PCR) and protein level (Western blot). PI3K kinase activities were measured using immunoprecipitation‐based in vitro kinase assay. The AR–DNA‐binding activity was determined using chromatin‐immunoprecipitation (ChIP) assay.

RESULTS

First, at the cellular plasma membrane, disrupting the integrity of caveolae microdomain with methyl‐β‐cyclodextrin (M‐β‐CD) abolished androgen‐induced AR transactivation and gene expression. Then, knocking down caveolae structural proteins caveolin‐1 or ‐2 with the gene‐specific siRNAs significantly reduced androgen‐induced AR transactivation. Next, silencing Gαs and Gα12 genes but not other G‐proteins blocked androgen‐induced AR transactivation and cell proliferation. Consistently, overexpression of Gαs or Gα12 active mutants enhanced androgen‐induced AR transactivation, of which Gαs active mutant sensitized the AR to castration‐level of androgen (R1881). Most interestingly, knocking down Gαs but not Gα12 subunit significantly suppressed androgen‐stimulated PI3K p110beta activation. However, ChIP analysis revealed that both Gαs or Gα12 subunits are involved in androgen‐induced AR interaction with the AR target gene PSA promoter region.

CONCLUSION

These data suggest that caveolae‐associated G‐protein alpha subunits are involved in AR transactivation by modulating the activities of different PI3K isoforms. Prostate 71:1276–1286, 2011. © 2011 Wiley‐Liss, Inc.
High‐dose‐rate brachytherapy boost to the dominant intra‐prostatic tumor region: Hemi‐irradiation of prostate cancer
Authors: Schick Ulrike , Popowski Youri , Nouet Philippe , Bieri Sabine , Rouzaud Michel , Khan Haleem , Weber Damien Charles , Miralbell Raymond
Published: February 2011

BACKGROUND

To assess the feasibility, toxicity, and outcome of prostate hemi‐irradiation with a high‐dose‐rate brachytherapy (HDR‐BT) boost for patients presumed to harbor dominant intra‐prostatic tumors in a single lobe.

METHODS

After 3D conformal external radiotherapy (3DCRT) to 64–64.4 Gy, 77 patients with non‐metastatic locally aggressive prostate cancer have been treated from 2000 to 2004, with HDR‐BT using temporary open MRI‐guided 192Ir implants, to escalate the dose in the boost region. Twenty patients (26%) had one lobe involvement (i.e., one sided endorectal MRI, rectal examination, and biopsies) and were boosted to one side of the gland only. A dose of 12, 14, and 16 Gy in two fractions was delivered to 5, 6, and 9 patients, respectively.

RESULTS

After a median follow‐up 69 months, no differences in late rectal toxicity were observed between the unilaterally and bilaterally irradiated cohorts. Although, grade 2 late urinary toxicity was worse in the hemi‐irradiated group (P = 0.03), severe grade ≥3 late urinary toxicity at 5 years was not different: 10% versus 8.8% in the unilaterally and bilaterally irradiated cohorts, respectively. Grade 4 late urinary toxicity, however, was exclusively observed in patients boosted to both lobes (5/57, 8.8%). Five‐year biochemical relapse‐free survival was 79.7% versus 70.5% for the unilateral and bilateral boost groups, respectively (P = 0.99).

CONCLUSION

Prostate hemi‐irradiation with a HDR‐BT boost to the dominant tumor region may be considered when rectal examination, MRI, and biopsies suggest one lobe involvement. Nevertheless, strict dosimetric optimization is needed in order to further reduce the risk of late severe toxicity. Prostate 71:1309–1316, 2011. © 2011 Wiley‐Liss, Inc.
Reduced levels of 5‐α reductase 2 in adult prostate tissue and implications for BPH therapy
Authors: Niu Yinong , Ge Rongbin , Hu Libing , Diaz Christian , Wang Zongwei , Wu Chin‐Lee , Olumi Aria F.
Published: February 2011

BACKGROUND

5‐α reductase 2 (5‐AR 2) is a key enzyme that is responsible of proper development of prostate tissue. Inhibition of 5‐AR 2 has proven to be efficacious for management of urinary symptoms secondary benign prostatic hyperplasia (BPH). However, some patients are resistant to the therapeutic effects of 5‐AR 2 inhibitor. We wished to determine why some benign non‐cancerous adult human prostates do not express 5‐AR 2, and hypothesized that methylation of 5‐AR 2 promoter region correlated with low expression of 5‐AR 2 protein.

METHODS

The transition zone of 42 human prostate tissues after radical prostatectomy was used for evaluation. Initially, 21 paraffin embedded samples were used to assess immunoreactivity to 5‐AR 2 antibody in non‐cancerous BPH samples. In the next 21 samples, fresh frozen prostate transition zone samples without cancer were assessed for immunoreactivity and methylation of the 5‐AR 2 promoter using methyl‐specific PCR.

RESULTS

We show that 6/21 (29%) of benign human prostate samples did not express the 5‐AR 2 protein. Moreover, the promoter region of 5‐AR 2 contains a CpG island that is methylated in benign prostate epithelial cells in culture and also in 39% (7/18) human prostate tissues. We show a strong correlation between methylation of the 5‐AR 2 promoter region and absence of 5‐AR 2 protein expression (P = 0.0025, Fisher's exact test).

CONCLUSIONS

Methylation of 5‐AR 2 promoter may account for low or absent expression of 5‐AR 2 in some human adult prostate tissues. Prostate 71:1317–1324, 2011. © 2011 Wiley‐Liss, Inc.
Construction of tissue micro array from prostate needle biopsies using the vertical clustering re‐arrangement technique
Authors: Fridman Eduard , Daya Dean , Srigley John , Whelan Kaitlyn F. , Lu Jian‐Ping , Pinthus Jehonathan H
Published: February 2011

BACKGROUND

Tissue microarray (TMA) allows for simultaneous rapid expression analysis of multiple molecular targets in many tissue specimens. TMA's are specifically in demand for the screening for diagnostic and prognostic markers in prostate cancer (PC). Consequently, TMAs from prostate needle biopsy (PNB) material taken at diagnosis before any treatment commenced are in demand. However, since PNB contain only limited amount of tumor arranged within a very thin tissue core, TMA construction from PNB is problematic.

METHODS

Archival PNB from 30 PC patients with variable Gleason scores (6–10) and % of cores involvement (30–90%) were used. Following selection of representative cores, the paraffin blocks were melted. Each core was sectioned into equal parts of 3–4 mm in length. For each case, a group of fragments was then re‐embedded in a vertical orientation. Using Manual TMA Apparatus, 2 mm cores from each of the vertically rearranged fragments were harvested. Sections (4 µm) were stained with H&E and with high‐molecular weight cytokeratin (HMWCK), PIN‐cocktail (p63 + p504S), and PSA immunohistochemical stains.

RESULTS

A TMA from PNB with a capacity of 80 serial 4 µm sections was constructed. In all cases, identical tumor and neighboring tissue morphology (atrophic changes and high‐grade prostatic intra‐epithelial neoplasia) with no loss of tissue was evident.

CONCLUSIONS

The vertical clustering re‐arrangement (VCR) technique is suitable for large scale construction of TMA blocks from PNB maintaining the morphological and immunohistochemical characteristics of the original samples. This method is promising both in terms of archival tissue preservation and biomarkers research. Prostate 71:1374–1381, 2011. © 2011 Wiley‐Liss, Inc.
Design, synthesis and structure–activity relationship of novel coumarin derivatives
Authors: Guan Ai‐Ying , Liu Chang‐Ling , Li Miao , Zhang Hong , Li Zhi‐Nian , Li Zheng‐Ming
Published: February 2011

BACKGROUND: The lead coumarin derivative (E)‐methyl 3‐methoxy‐2‐[2‐(4‐methylcoumarin‐7‐yloxymethyl)phenyl]acrylate was discovered by using an intermediate derivatisation method. To discover new coumarin derivatives with improved activity, a series of substituted coumarins were synthesised and bioassayed.

RESULTS: The compounds were identified by 1H NMR, IR, MS and elemental analysis. Bioassays demonstrated that some of the title compounds exhibited excellent fungicidal activity against cucumber downy mildew at 25 mg L−1. The relationship between structure and fungicidal activity is reported.

CONCLUSION: The present work demonstrates that coumarin derivatives containing methoxyacrylate moieties can be used as possible lead compounds for developing novel fungicides. Copyright © 2011 Society of Chemical Industry
NICE's future without a veto on the use of expensive drugs
Authors: Chaplin Steve
Published: February 2011

Steve Chaplin describes NICE's future role after it loses the power to decide whether the use of a new drug will be cost effective. Copyright © 2011 Wiley Interface Ltd
Current recommended treatments for head lice and scabies
Authors: Connolly Maureen
Published: February 2011

Eradication of head lice and scabies stands the best chance of success if undertaken correctly and if all affected individuals are treated at the same time. Our Drug review considers the available treatment options, followed by sources of further information and a review of the prescription
data. Copyright © 2011 Wiley Interface Ltd
Cloud statistics and cloud radiative effect for a low‐mountain site
Authors: Ebell Kerstin , Crewell Susanne , Löhnert Ulrich , Turner David D. , O'Connor Ewan J.
Published: February 2011

In 2007, the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) was operated for a nine‐month period in the Murg Valley, Black Forest, Germany, in support of the Convective and Orographically‐induced Precipitation Study (COPS). The synergy of AMF and COPS partner instrumentation was exploited to derive a set of high‐quality thermodynamic and cloud property profiles with 30 s resolution. In total, clouds were present 72% of the time, with multi‐layer mixed phase (28.4%) and single‐layer water clouds (11.3%) occurring most frequently. A comparison with the Cloudnet sites Chilbolton and Lindenberg for the same time period revealed that the Murg Valley exhibits lower liquid water paths (LWPs; median = 37.5 g m−2) compared to the two sites located in flat terrain. In order to evaluate the derived thermodynamic and cloud property profiles, a radiative closure study was performed with independent surface radiation measurements. In clear sky, average differences between calculated and observed surface fluxes are less than 2% and 4% for the short wave and long wave part, respectively. In cloudy situations, differences between simulated and observed fluxes, particularly in the short wave part, are much larger, but most of these can be related to broken cloud situations. The daytime cloud radiative effect (CRE), i.e. the difference of cloudy and clear‐sky net fluxes, has been analysed for the whole nine‐month period. For overcast, single‐layer water clouds, sensitivity studies revealed that the CRE uncertainty is likewise determined by uncertainties in liquid water content and effective radius. For low LWP clouds, CRE uncertainty is dominated by LWP uncertainty; therefore refined retrievals, such as using infrared and/or higher microwave frequencies, are needed. Copyright © 2011 Royal Meteorological Society
Processes driving deep convection over complex terrain: a multi‐scale analysis of observations from COPS IOP 9c
Authors: Corsmeier U. , Kalthoff N. , Barthlott C. , Aoshima F. , Behrendt A. , Di Girolamo P. , Dorninger M. , Handwerker J. , Kottmeier C. , Mahlke H. , Mobbs S.D. , Norton E.G. , Wickert J. , Wulfmeyer V.
Published: February 2011

The ‘Convective and Orographically‐induced Precipitation Study’ (COPS) analyses the processes driving deep convection over complex terrain. Convection initiation (CI) is mainly not only expressed by a single process, but by a variety of them, which interact on different scales in time and space and finally can lead to deep convection. A study of such a case over inhomogeneous terrain is presented in this article. Data from the COPS network of stations are taken to identify the time and location of CI. In many cases this is not the same location as the first convective clouds, showers or even thunderstorms. It is shown that the interaction of the CI processes on multiple scales locally leads to either deep convection and severe storms or calm weather. The boundary conditions between the different outcomes are narrow.

During IOP 9c (20 July 2007), a mesoscale convective system (MCS) embedded in a surface low over eastern France propagated north‐eastward and a gust front of the MCS reached the COPS area. During the passage of the gust front through the Rhine valley, convective activity was significantly reduced. The gust front reached the slope of the Black Forest, and the warm and humid air above the mountain range prior to the gust front was lifted up to 2000 m within a short time period. Within the air prior to the gust front aloft from the surface, CI started along a north–south oriented line above the crest. Due to insolation ahead of the gust front, a convergence line developed. The interaction of local‐scale orographic winds, the regional‐scale gust front, the mesoscale convergence line, and the synoptic‐scale cold front led to a squall line. Finally, individual severe convective cells formed along the outer section of the synoptic‐scale cold front. Copyright © 2011 Royal Meteorological Society
Observation of convection initiation processes with a suite of state‐of‐the‐art research instruments during COPS IOP 8b
Authors: Behrendt A. , Pal S. , Aoshima F. , Bender M. , Blyth A. , Corsmeier U. , Cuesta J. , Dick G. , Dorninger M. , Flamant C. , Di Girolamo P. , Gorgas T. , Huang Y. , Kalthoff N. , Khodayar S. , Mannstein H. , Träumner K. , Wieser A. , Wulfmeyer V.
Published: February 2011

In the afternoon of 15 July 2007, a thunderstorm was initiated within a line of cumulus clouds which formed parallel to the crest of the Black Forest mountains during the Intensive Observation Period (IOP) 8b of the Convective and Orographically‐induced Precipitation Study (COPS). This paper extends the analysis of processes that led to convection initiation (CI), i.e. the transition from shallow to deep convection, on this day with the data from several COPS instruments that have not been considered in previous studies. In particular, the boundary‐layer structure, lids and the water‐vapour field in the pre‐convective environment of the event are discussed. For this purpose, we investigated measurements of water‐vapour lidars, temperature lidars and wind lidars, profiles from radiosondes, in situ aircraft data and gridded data of weather stations as well as GPS integrated‐water‐vapour data and satellite imagery. Thermally driven circulation systems formed over both the Black Forest and the Vosges mountain ranges which resulted in local convergence zones. These superimposed with the large‐scale convergence in the Black Forest area. In the presence of sufficient moisture and updraught, clouds formed close to the mountain crests. The related latent‐heat release allowed larger thermals to be produced, which may have had a positive feedback on stabilizing these convergence zones as a whole. We believe that differences in the moisture field explain why convection remained shallow and sparse over the Vosges mountains because these differences were responsible for differences in convective inhibition (CIN). The stationary location of the convergence zone over the southern Black Forest was probably decisive for CI because it constantly transported sensible and latent heat into the area in which CI took place. Copyright © 2011 Royal Meteorological Society
Soil moisture variability and its influence on convective precipitation over complex terrain
Authors: Hauck Christian , Barthlott Christian , Krauss Liane , Kalthoff Norbert
Published: February 2011

Soil moisture monitoring data from the Convective and Orographically‐induced Precipitation Study (COPS) 2007 are combined with operational and high‐resolution simulations with the weather forecast system GME/COSMO‐DE to analyse the discrepancies between observed and modelled soil moisture fields and their potential impacts on convective precipitation forecasts. We use data from the newly installed soil moisture monitoring network comprising 47 stations with soil moisture sensors installed at three different depths within the COPS area in southwest Germany. The obtained soil moisture fields are compared to their related representation within the global model GME interpolated with high‐resolution soil and surface data to a 2.8 km resolution yielding soil moisture values on the same grid as the high‐resolution model COSMO‐DE. Systematic differences between modelled and measured soil moisture values are found and used to determine the potential impact of large soil moisture biases for the modelling of convective processes. This is achieved by conducting sensitivity tests using COSMO‐DE, in which the initialisation fields of soil moisture are varied. Results show a general mean bias towards too dry soil conditions, both in GME during the whole COPS period, as well as in the high‐resolution modelling of specific COPS IOPs with COSMO‐DE. The influence of this bias on simulated precipitation is significant and non‐trivial and depends on the specifics of the analysed case study. The results presented in this study demonstrate that soil moisture has a considerable impact on convection‐related parameters over complex and heterogeneous terrain, but that no simple relationship regarding the sign of the soil moisture–precipitation feedback could be identified due to a complex interplay between various factors that favour or inhibit convection initiation. Copyright © 2011 Royal Meteorological Society
Increasing the output length of zero‐error dispersers
Authors: Gabizon Ariel , Shaltiel Ronen
Published: February 2011

Let
$\cal{C}$
be a class of probability distributions over a finite set Ω. A function $D : \Omega \mapsto\{0,1\}^{m}$
is a disperser for $\cal{C}$
with entropy threshold
$k$
and error
$\epsilon$
if for any distribution X in $\cal{C}$
such that X gives positive probability to at least $2^{k}$
elements we have that the distribution $D(X)$
gives positive probability to at least $(1-\epsilon)2^{m}$
elements. A long line of research is devoted to giving explicit (that is polynomial time computable) dispersers (and related objects called “extractors”) for various classes of distributions while trying to maximize m as a function of k. For several interesting classes of distributions there are explicit constructions in the literature of zero‐error dispersers with “small” output length m.

In this paper we develop a general technique to improve the output length of zero‐error dispersers. This strategy works for several classes of sources and is inspired by a transformation that improves the output length of extractors (which was given by Shaltiel (CCC'06; Proceedings of the 21st Annual IEEE Conference on Computational Complexity, (2006) 46–60.) building on earlier work by Gabizon, Raz and Shaltiel (SIAM J Comput 36 (2006) 1072–1094). Our techniques are different than those of Shaltiel (CCC'06; Proceedings of the 21st Annual IEEE Conference on Computational Complexity (2006) 46–60) and in particular give non‐trivial results in the errorless case.

Using our approach we construct improved zero‐error 2‐source dispersers. More precisely, we show that for any constant
$\delta >0$
there is a constant $\eta >0$
such that for sufficiently large n
there is a poly‐time computable function $D :\{0,1\}^{n}\times\{0,1\}^{n}\mapsto\{0,1\}^{\eta n}$
such that for every two independent distributions $X_1,X_2$
over $\{0,1\}^{n}$
each with support size at least $2^{\delta n}$, the output distribution $D(X_1,X_2)$
has full support. This improves the output length of previous constructions by Barak, Kindler, Shaltiel, Sudakov and Wigderson (Proceedings of the 37th Annual ACM Symposium on Theory of Computing (2005) 1–10) and has applications in Ramsey theory and in improved constructions of certain data structures from the work of Fiat and Naor [SIAM J Comput 22 (1993)].

We also use our techniques to give explicit constructions of zero‐error dispersers for bit‐fixing sources and affine sources over polynomially large fields. These constructions improve the best known explicit constructions due to Rao (unpublished data) and Gabizon and Raz [Combinatorica 28 (2008)] and achieve
$m=\Omega(k)$
for bit‐fixing sources and $m=k-o(k)$
for affine sources over polynomial size fields. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2011
Design and implementation of an adaptive Web2.0 QoS‐based home appliance control service platform
Authors: Huang Chung‐Ming , Ku Hao‐Hsiang , Chao Yu‐Chang , Lin Cheng‐Wei , Chen Yen‐Wen
Published: February 2011

The rapid progress of information techniques enables people to have a relatively convenient environment and life. This study designs and develops the Web2.0‐based Home Appliances controL sErvice platform (WHALE) for users to easily control home appliances. WHALE is a three‐tier architecture, which consists of Device Detection and Registration Service Platform (DDRSP), Web2.0 Service Platform (WSP), and Common Service Platform (CSP). WHALE is based on the standards of Devices Profile for Web Services (DPWS), Open Services Gateway initiative (OSGi), and Web2.0 techniques. Users can use many kinds of handheld devices to get services from WSP. When DDRSP finds a new home appliance, this home appliance will be registered into CSP. CSP records the related information and services which are provided by this home appliance. WSP not only integrates and shows the related services of all home appliances but also provides controlling interfaces to control the actions of all home appliances. All delivered messages are based on Simple Object Access Protocol (SOAP) and Web Services Description Language (WSDL). Furthermore, for the Web QoS (Quality of Service) strategy, this study designs and proposes an Intelligent Web qualIty of Service‐aware maTching (iWIST) model to satisfy different characteristics of the user's requirements. iWIST consists of Components Classifier, Admission Controller, and Dynamic Content Adaptor. Component Classifier can classify users' requesting components with different QoS constraints. Admission Controller determines the maximum available components for the user. Dynamic Content Adaptor dynamically delivers component information to users. Experiment results illustrate that WHALE can provide appropriate contents with low response time to users. Finally, WHALE has integrity, scalability, operability, adaptivity, and extensibility functions. It can be a reference model for developing home appliance controllers in the future. Copyright © 2011 John Wiley & Sons, Ltd.
Concise Review: Adipose-Derived Stromal Cells for Skeletal Regenerative Medicine
Authors: Levi Benjamin , Longaker Michael T.
Published: February 2011

As the average age of the population grows, the incidence of osteoporosis and skeletal diseases continues to rise. Current treatment options for skeletal repair include immobilization, rigid fixation, alloplastic materials, and bone grafts, all which have significant limitations, especially in the elderly. Adipose-derived stromal cells (ASCs) represent a readily available abundant supply of mesenchymal stem cells, which demonstrate the ability to undergo osteogenesis in vitro and in vivo, making ASCs a promising source of skeletal progenitor cells. Current protocols allow for the harvest of over one million cells from only 15 ml of lipoaspirate. Despite the clinical use of ASCs to treat systemic inflammatory diseases, no large human clinical trials exist using ASCs for skeletal tissue engineering. The aim of this review is to define ASCs, to describe the isolation procedure of ASCs, to review the basic biology of their osteogenic differentiation, discuss cell types and scaffolds available for bone tissue engineering, and finally, to explore imaging of ASCs and their potential future role in human skeletal tissue engineering efforts.
Conditional Activation of Bmi1 Expression Regulates Self-renewal, Apoptosis, and Differentiation of Neural Stem/Progenitor Cells In Vitro and In Vivo
Authors: Yadirgi Gokhan , Leinster Veronica , Acquati Serena , Bhagat Heeta , Shakhova Olga , Marino Silvia
Published: February 2011

The Polycomb group protein Bmi1 is a key regulator of self-renewal of embryonic and adult central nervous system stem cells, and its overexpression has been shown to occur in several types of brain tumors. In a Cre/LoxP-based conditional transgenic mouse model, we show that fine-tuning of Bmi1 expression in embryonic neural stem cell (NSC) is sufficient to increase their proliferation and self-renewal potential both in vitro and in vivo. This is linked to downregulation of both the ink4a/ARF and the p21/Foxg1 axes. However, increased and ectopic proliferation induced by overexpression of Bmi1 in progenitors committed toward a neuronal lineage during embryonic cortical development, triggers apoptosis through a survivin-mediated mechanism and leads to reduced brain size. Postnatally, however, increased self-renewal capacity of neural stem/progenitor cells (NSPC) is independent of Foxg1 and resistance to apoptosis is observed in neural progenitors derived from NSC-overexpressing Bmi1. Neoplastic transformation is absent in mice-overexpressing Bmi1 aged up to 20 months. These studies provide strong evidence that fine tuning of Bmi1 expression is a viable tool to increase self-renewal capacity of NSCs both in vitro and in vivo without eliciting neoplastic transformation of these cells.
Reprogramming of Trophoblast Stem Cells into Pluripotent Stem Cells by Oct4
Authors: Wu Tong , Wang Haitao , He Jing , Kang Lan , Jiang Yonghua , Liu Jinchao , Zhang Yu , Kou Zhaohui , Liu Lijun , Zhang Xuehong , Gao Shaorong
Published: February 2011

ESCs and trophoblast stem (TS) cells are both derived from early embryos, yet these cells have distinct differentiation properties. ESCs can differentiate into all three germ layer cell types, whereas TS cells can only differentiate into placental cells. It has not been determined whether TS cells can be converted into ES-like pluripotent stem (PS) cells. Here, we report that overexpression of a single transcription factor, Oct4, in TS cells is sufficient to reprogram TS cells into a pluripotent state. These Oct4-induced PS (OiPS) cells have the epigenetic characteristics of ESCs, including X chromosome reactivation, elevated H3K27 me3 modifications, and hypomethylation of promoter regions in Oct4 and Nanog genes. Meanwhile, methylation of promoter region in the Elf5 gene occurred during reprogramming of TS cells. The gene expression profile of OiPS cells was very similar to ESCs. Moreover, OiPS cells can differentiate into the three germ layer cell types in vitro and in vivo. More importantly, chimeric mice with germline transmission could be efficiently produced from OiPS cells. Our results demonstrate that one single transcription factor, Oct4, could reprogram the nonembryonic TS cells into PS cells.
Progesterone influences postischemic synaptogenesis in the CA1 region of the hippocampus in rats
Authors: Zhao Yuanzheng , Wang Jianping , Liu Chunling , Jiang Chao , Zhao Chunyan , Zhu Zhongjun
Published: February 2011

Synaptogenesis is considered necessary for learning and memory. Recently, it has been suggested that progesterone (PROG) effects synaptogenesis of the cerebellar Purkinje cell, helps alleviate symptoms of multiple sclerosis and helps arrest spinal cord neurodegeneration. However, it is unclear whether PROG influences synaptic plasticity in central nervous system neurons after global cerebral ischemia. The purpose of the present study was to reveal PROG's influence on postischemic synaptogenesis in the CA1 region of the hippocampus in rats. Global cerebral ischemia was induced in male Sprague‐Dawley rats by the 4‐vessel occlusion (4‐VO) method. To determine the amount of synaptogenesis, growth‐associated protein 43 (GAP‐43) and synaptophysin (SYP) expression were examined by immunohistochemical, reverse transcription‐polymerase chain reaction (RT‐PCR) and western blot techniques. Histological and behavioral tests were used to indicate the effect of PROG on global cerebral ischemia. Recovery times were 3, 7, 14, 21, and 35 days after surgery. We found that PROG increased the expression of GAP‐43 and SYP. In addition, there was a significant increase in neuronal cell density and improvement ability to remain on an accelerating rotarod observed in the 4‐VO rats treated with PROG compared to vehicle. We propose that PROG helped enable synaptogenesis in the CA1 region of therat hippocampus after global cerebral ischemia in rats. Synapse, 2011. © 2011 Wiley‐Liss, Inc.
Imaging of gynecological disease (6): clinical and ultrasound characteristics of ovarian dysgerminoma
Authors: Guerriero S. , Testa A. C. , Timmerman D. , Van Holsbeke C. , Ajossa S. , Fischerova D. , Franchi D. , Leone F. P. G. , Domali E. , Alcazar J. L. , Parodo G. , Mascilini F. , Virgilio B. , Demidov V. N. , Lipatenkova J. , Valentin L.
Published: February 2011

Objectives

To describe the clinical history and ultrasound findings in patients with ovarian dysgerminoma.

Methods

This was a retrospective study of patients with a histological diagnosis of ovarian dysgerminoma who had undergone preoperative ultrasound examination. The patients were identified from the databases of 11 ultrasound centers. The tumors were described by the principal investigator at each contributing center on the basis of ultrasound images, ultrasound reports and research protocols (when applicable) using the terms and definitions of the International Ovarian Tumor Analysis (IOTA) group. In addition, three authors reviewed all available electronic ultrasound images (gray‐scale images and color/power Doppler images were available for 18 patients and 14 patients, respectively) and described them using subjective evaluation of gray‐scale and color Doppler ultrasound findings (here called pattern recognition).

Results

Twenty‐one patients with ovarian dysgerminoma were identified (including one woman with bilateral masses). Twenty patients had a primary ovarian dysgerminoma (including the one with bilateral masses) and one patient had a recurrence of dysgerminoma in her retained ovary. One of the 21 patients was pregnant. All tumors except one were pure dysgerminomas, one being a mixed germinal cell tumor with 30% dysgerminoma component. Median age was 20 (range, 16–31) years. Information on clinical symptoms was available for 18 patients. In four patients, the tumor was detected incidentally, whereas 14 patients presented with one or more of the following symptoms: acute pain (n = 4), chronic pain (n = 8), bloating (n = 8), menstrual disorders (n = 5) and infertility problems (n = 1). One (5%) patient had ascites. Using the IOTA terms and definitions, all but one dysgerminoma were moderately (43%) or very well (50%) vascularized solid tumors. One tumor was multilocular–solid. According to pattern recognition, most dysgerminomas were highly vascularized, purely solid tumors with heterogeneous internal echogenicity divided into several lobules, had a smooth and sometimes lobulated contour and were well‐defined relative to the surrounding organs.

Conclusion

The ultrasound finding of a highly vascularized, large, solid, lobulated adnexal mass with irregular internal echogenicity in a woman 20–30 years old should raise the suspicion of ovarian dysgerminoma. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal cardiac dimensions at 14–40 weeks' gestation obtained using cardio‐STIC‐M
Authors: Luewan S. , Yanase Y. , Tongprasert F. , Srisupundit K. , Tongsong T.
Published: February 2011

Objectives

To establish normative reference ranges of fetal cardiac dimensions derived from volume datasets acquired using spatiotemporal image correlation with M‐mode display (cardio‐STIC‐M).

Methods

A cross‐sectional study was undertaken on singleton pregnancies with normal fetuses and accurate gestational ages. Cardio‐STIC volume datasets were acquired by experienced operators using a high‐resolution ultrasound machine; these were maneuvered to obtain a four chamber‐view with exactly horizontal interventricular septum (IVS). Cardiac dimensions were measured in STIC‐M‐mode using 4D View software.

Results

A total of 657 measurements, at a rate of between 15 and 37 per week, were obtained. Normal reference ranges for biventricular outer diameter, left and right ventricular inner diameter, left and right ventricular wall thickness, IVS thickness, left to right ventricular diameter ratio and left and right ventricular shortening fractions were constructed based on best‐fit equations as a function of gestational age, fetal head circumference and biparietal diameter. Thirty‐four volume datasets of abnormal fetal hearts were also separately assessed, many of which showed abnormal cardiac dimensions.

Conclusions

This is the first report on normal ranges of fetal cardiac dimensions constructed using the new cardio‐STIC‐M technology. Preliminary evaluation suggests that these reference ranges may be a useful tool in the assessment of fetal cardiac abnormalities. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
A generalisation of the Rayleigh distribution with applications in wireless fading channels
Authors: Gómez‐Déniz E. , Gómez‐Déniz L.
Published: February 2011

The signal received in a mobile radio environment exhibits rapid signal level fluctuations which are generally Rayleigh‐distributed. These result from interference by multiple scattered radio paths between the base station and the mobile receptor. Fading‐shadowing effects in wireless channels are usually modelled by means of the Rayleigh–Lognormal distribution (RL), which has a complicated integral form. The K‐distribution (K) is similar to RL but it has a simpler form and its probability density function admits a closed form; however, due to the Bessel function, parameter estimates are not direct. Another possible approach is that of the Rayleigh‐inverse Gaussian distribution (RIG). In this paper, an alternative is presented, a generalisation of the Rayleigh distribution which is simpler than the RL, K and RIG distributions, and thus more suitable for the analysis and design of contemporary wireless communication systems. Closed‐form expressions for the bit error rate (BER) for differential phase‐shift keying (DPSK) and minimum shift keying (MSK) modulations with the proposed distribution are obtained. Theoretical results based on statistically well‐founded distance measurements validate the new distribution for the cases analysed. Copyright © 2011 John Wiley & Sons, Ltd.
A seamless handoff scheme for IEEE 802.11 wireless networks
Authors: Yen Yun‐Sheng , Chang Ruay‐Shiung , Wu Chuan‐Yung
Published: February 2011

The advance of computer network technologies such as IEEE 802.11 wireless local area network has made it possible for users to connect to Internet almost anywhere. A mobile node (MN) is likely to move between different base stations while running applications. The IETF has defined the Mobile IP (MIP) to allow MNs to maintain their communication uninterrupted while roaming across different IP subnets. However, the mechanisms defined in MIP may cause undesired connection disruptions or packet losses, which will significantly degrade the quality of real‐time applications. It is an important and challenging issue to support seamless handoff management. To achieve seamless handoff, we propose a unified scheme to address application quality degradation. Our main contribution is the concept and implementation of utilising buffering and resending method to eliminate the packet losses while keeping the end‐to‐end delay of real‐time traffic flow in an acceptable value. The NS‐2 simulation results show that our proposed scheme can significantly maintain application quality during layer‐2 and ‐3 handoffs. Copyright © 2011 John Wiley & Sons, Ltd.
Multi‐cost routing for energy and capacity constrained wireless mesh networks
Authors: Kokkinos Panagiotis , Papageorgiou Christos , Varvarigos Emmanouel
Published: February 2011

We propose a class of novel energy‐efficient multi‐cost routing algorithms for wireless mesh networks, and evaluate their performance. In multi‐cost routing, a vector of cost parameters is assigned to each network link, from which the cost vectors of candidate paths are calculated using appropriate operators. In the end these parameters are combined in various optimization functions, corresponding to different routing algorithms, for selecting the optimal path. We evaluate the performance of the proposed energy‐aware multi‐cost routing algorithms under two models. In the network evacuation model, the network starts with a number of packets that have to be transmitted and an amount of energy per node, and the objective is to serve the packets in the smallest number of steps, or serve as many packets as possible before the energy is depleted. In the dynamic one‐to‐one communication model, new data packets are generated continuously and nodes are capable of recharging their energy periodically, over an infinite time horizon, and we are interested in the maximum achievable steady‐state throughput, the packet delay, and the energy consumption. Our results show that energy‐aware multi‐cost routing increases the lifetime of the network and achieves better overall network performance than other approaches. Copyright © 2011 John Wiley & Sons, Ltd.
Learning Options and Binomial Trees
Authors: Guthrie Graeme
Published: February 2011

This paper modifies the standard binomial option pricing approach to real options analysis so that it can incorporate learning options. These options allow a manager to gather information about a potential investment payoff prior to investment occurring. The project's overall volatility will vary in the run‐up to investment, being higher when the manager gathers more information about the eventual investment payoff. This paper shows how to construct a recombining tree for the project's anticipated value by making the time steps shorter during periods of high volatility. It describes a simple scheme for calculating the lengths of these steps and the risk‐neutral probabilities that are needed to calculate arbitrage‐free asset prices. Copyright © 2011 Wilmott Magazine Ltd.