bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary Colorectal Cancers and Their Subsequent Hepatic Metastases Are Genetically Different: Implications for Selection of Patients for Targeted Treatment
Authors: Vermaat Joost S. , Nijman Isaac J. , Koudijs Marco J. , Gerritse Frank L. , Scherer Stefan J. , Mokry Michal , Roessingh Wijnand M. , Lansu Nico , de Bruijn Ewart , van Hillegersberg Richard , van Diest Paul J. , Cuppen Edwin , Voest Emile E.
Published: December 2011

Purpose: In the era of DNA-guided personalized cancer treatment, it is essential to conduct predictive analysis on the tissue that matters. Here, we analyzed genetic differences between primary colorectal adenocarcinomas (CRC) and their respective hepatic metastasis.

Experimental Design: The primary CRC and the subsequent hepatic metastasis of 21 patients with CRC were analyzed using targeted deep-sequencing of DNA isolated from formalin-fixed, paraffin-embedded archived material.

Results: We have interrogated the genetic constitution of a designed “Cancer Mini-Genome” consisting of all exons of 1,264 genes associated with pathways relevant to cancer. In total, 6,696 known and 1,305 novel variations were identified in 1,174 and 667 genes, respectively, including 817 variants that potentially altered protein function. On average, 83 (SD = 69) potentially function-impairing variations were gained in the metastasis and 70 (SD = 48) variations were lost, showing that the primary tumor and hepatic metastasis are genetically significantly different. Besides novel and known variations in genes such as KRAS, BRAF, KDR, FLT1, PTEN, and PI3KCA, aberrations in the up/downstream genes of EGFR/PI3K/VEGF-pathways and other pathways (mTOR, TGFβ, etc.) were also detected, potentially influencing therapeutic responsiveness. Chemotherapy between removal of the primary tumor and the metastasis (N = 11) did not further increase the amount of genetic variation.

Conclusion: Our study indicates that the genetic characteristics of the hepatic metastases are different from those of the primary CRC tumor. As a consequence, the choice of treatment in studies investigating targeted therapies should ideally be based on the genetic properties of the metastasis rather than on those of the primary tumor. Clin Cancer Res; 18(3); 688–99. ©2011 AACR.
Cerebral Aneurysm Sac Growth as the Etiology of Recurrence After Successful Coil Embolization
Authors: Hasan David M. , Nadareyshvili Alexander I. , Hoppe Anna L. , Mahaney Kelly B. , Kung David K. , Raghavan Madhavan L.
Published: December 2011

Background and Purpose—

Coil compaction is thought to be the main mechanism for recurrence in cerebral aneurysms with previously successful coil embolization. We hypothesize that sac growth may be equally or more important. The objective was to study the relative roles of coil compaction and sac growth as explanations for aneurysm recurrence requiring retreatment in a study population using quantitative 3D image processing methods.

Methods—

From July 2009 to December 2010, 175 aneurysms were coiled at the University of Iowa hospitals and clinics. Eight aneurysms had major recurrence requiring retreatment (4.4–12.1 months between procedures; mean: 7.2 months). The 3D structures of the vessel and coil mass were reconstructed using rotational angiography data scanned before and after both initial coil embolization and retreatment. Changes in the sac and coil mass over time were visualized using model registration techniques and quantified using volume calculations.

Results—

All 8 of the coiled aneurysms with major recurrence had significant aneurysm sac growth (15% to 102% increase in volume), independent of change in coil volume. Five aneurysms with major recurrence had sufficient data for assessment of coil compaction. The coil mass volume decreased in 1 aneurysm (12% compaction by volume), did not change significantly in 1 aneurysm (increased by 1%), and significantly increased in 3 aneurysms (8%, 21%, and 25%) between the first treatment and before the second treatment.

Conclusions—

In this study population, aneurysm sac growth, not coil compaction, was the primary mechanism associated with recurrence after initial coil embolization.
Minority Vulnerability in Privileged Occupations
Authors: Bielby William T.
Published: December 2011

Building on recent work on contemporary forms of bias in meritocratic personnel systems, the author assesses sources of racial disadvantage in an output-based pay-for-performance system for compensating financial advisers in a large financial services firm. Using data from expert reports submitted in racial discrimination litigation, the author shows how racial differences in access to white wealth, limits on African Americans’ full participation in broker teams, racialized approaches to multicultural marketing, and diffuse lines of authority for diversity and nondiscrimination created racial barriers that were sustained and amplified by a cumulative advantage system for allocating productivity-enhancing resources. The author concludes with a discussion of management strategies for minimizing minority vulnerability in privileged professions and the challenges faced when the sources of bias are neither unconscious nor unintended but are instead located at least in part in racially segregated social relations and power differences among professionals who hold formally equivalent positions in a company’s job structure.
Key Factors in Frame Building
Authors: Hänggli Regula
Published: December 2011

In this article, the author focuses on the relationship between political actors and the mass media. The author uses media frames as dependent variables and investigates the factors that influence the presence and frequency of frames applied by journalists (the frames in “news media”). This has come to be known as frame building. The author argues that there are at least three important factors in frame building: power, the salience of the frames in the media input, and the multiplication effect of the minister. Using data from content analyses of campaign material and news media and from interviews with political actors, the author finds support that for frame presence, power is important. For frame frequency, the salience of the frames in the media input and the minister are crucial.
A Limited Sampling Schedule to Estimate Mycophenolic Acid Area Under the Concentration‐Time Curve in Hematopoietic Cell Transplantation Recipients
Authors: Li Hong , Mager Donald E. , Bemer Meagan J. , Salinger David H. , Vicini Paolo , Sandmaier Brenda M. , Nash Richard , McCune Jeannine S.
Published: December 2011

Mycophenolate mofetil (MMF) is a key component of postgrafting immunosuppression in hematopoietic cell transplant (HCT) recipients. The plasma area under the curve (AUC) of its active metabolite, mycophenolic acid (MPA), is associated with MMF efficacy and toxicity. This study developed a population pharmacokinetic model of MPA in HCT recipients and created limited sampling schedules (LSSs) to enable individualized pharmacotherapy. A retrospective evaluation of MPA concentration‐time data following a 2‐hour MMF intravenous (IV) infusion was conducted in 77 HCT recipients. The final model consisted of 1 and 2 compartments for MMF and MPA pharmacokinetics, respectively. The mean estimated values (coefficient of variation, %) for total systemic clearance, distributional clearance, and central and peripheral compartment volumes of MPA were 36.9 L/h (34.5%), 15.3 L/h (80.4%), 11.9 L (71.7%), and 182 L (127%), respectively. No covariates significantly explained variability among individuals. Optimal LSSs were derived using a simulation approach based on the scaled mean squared error. A 5‐sample schedule of 2, 2.5, 3, 5, and 6 hours from the start of the infusion precisely estimated MPA AUC0‐12h for Q12‐hour IV MMF. A comparable schedule (2, 2.5, 3, 4, and 6 hours) similarly estimated MPA AUC0–8 h for Q8‐hour dosing.
Efficacy of low-frequency low-intensity electrotherapy in the treatment of breast cancer-related lymphoedema: a cross-over randomized trial
Authors: Belmonte Roser , Tejero Marta , Ferrer Montse , Muniesa Josep M , Duarte Esther , Cunillera Oriol , Escalada Ferran
Published: December 2011

Objective: To compare the efficacy of low-frequency low-intensity electrotherapy and manual lymphatic drainage in the treatment of chronic upper limb breast cancer-related lymphoedema.

Design: Cross-over single-blind random clinical trial.

Setting: Rehabilitation service.

Participants: Thirty-six women with chronic upper limb breast cancer-related lymphoedema.

Methods: Patients were randomized to undergo 10 sessions of manual lymphatic drainage followed by 10 sessions of low-frequency low-intensity electrotherapy or to undergo first low-frequency low-intensity electrotherapy followed by manual lymphatic drainage. There was a month of washout time between treatments. Each patient was examined just before and after each treatment. Researchers and outcome assessors were blinded for assigned treatment.

Measures: Outcomes were lymphoedema volume, pain, heaviness and tightness, and health-related quality of life measured with the Functional Assessment of Cancer Therapy Questionnaire for Breast Cancer version 4 (FACT-B+4). Carry-over, period and treatment effects were analysed. Treatment effect was assessed using paired t-test.

Results: Thirty patients finalized treatment. Comparing the changes in low-frequency low-intensity electrotherapy with manual lymphatic drainage changes, there were no significant differences. Low-frequency low-intensity electrotherapy did not reduce lymphoedema volume (mean of change = 19.77 mL, P = 0.36), but significant reductions were observed in pain, heaviness and tightness (mean of change = 13.1, 16.2 and 6.4 mm, respectively), and FACT-B+4 summaries improved significantly (Trial Outcome Index mean of change = 5.4, P = 0.015). Manual lymphatic drainage showed no significant changes in any of the outcomes

Conclusion: Although there are no significant differences between treatment changes, the observed trend towards a better health-related quality of life is remarkable in low-frequency low-intensity electrotherapy.
Pain measurement: Visual Analogue Scale (VAS) and Verbal Rating Scale (VRS) in clinical trials with OTC analgesics in headache
Authors: Aicher B , Peil H , Peil B , Diener H-C
Published: December 2011

Aim: The aim was to assess the performance of the Visual Analogue Scale (VAS) in patients recruited in a clinical trial with over the counter analgesics in headache.

Methods: The Thomapyrin Study showed the significant superiority of the fixed combination of acetylsalicylic acid + paracetamol + caffeine over the combination without caffeine, the single preparations, and placebo in the treatment of headache. Patients enrolled into the study were trained in the handling of the VAS by naming categories of a 6-point Verbal Rating Scale (VRS). These data were used to evaluate the level of order consistency between the VAS and VRS, to deduce cut-off points for rescaling the continuous VAS into a discrete ordinal scale using the receiver operating characteristic methodology, and to assess the test-retest performance.

Results: Approximately 75% of the patients recorded the pain intensity on the VAS in the same order as given on the VRS. However, in 12.6% of patients, the German terms ‘leicht’ (mild) and ‘mäßig’ (moderate) were mixed up regarding their order on the VAS. Substantial overlapping of the frequency distributions of the VAS assessment were found for the VRS categories mild and moderate pain as well as severe and very severe pain. Grouping of the VAS assessments into a discrete ordinal scale necessitated a non-equidistant rescaling based on the categories of the VRS. By means of analysis of the receiver operating characteristic curves, the following cut-off points were determined on a 100 mm VAS: no pain 0–2 mm, mild pain 2–17 mm, moderate pain 17–47 mm, severe pain 47–77 mm, very severe pain 77–96 mm, most severe pain imaginable 96–100 mm. Repeated assessment up to several months after the first assessment demonstrated a test-retest agreement on the VAS in 61.0–91.4% of the patients, depending on the VRS category.

Conclusions: This study shows that the VRS categories cannot be presented in an equidistant manner on the VAS, and that contrary to previous assumptions, the pain intensity descriptors are less clear and can have different meanings in different languages. Therefore, both in the 3rd edition of the International Headache Classification (ICHD-III) and in the guidelines for clinical trials of patients with headache illnesses, rather than a 4-grade VRS, a 6-grade or higher level VRS or a VAS should be recommended, with correspondingly broadly defined anchor points.
Associations of socioeconomic status with migraine and non-migraine headache
Authors: Winter Anke C , Berger Klaus , Buring Julie E , Kurth Tobias
Published: December 2011

Background: Migraine has been linked with several measures of socioeconomic status (SES). However, results are inconsistent and data on the association between SES and non-migraine headache, migraine subtypes and migraine frequency are sparse.

Methods: We conducted a cross-sectional study among 36,858 participants in the Women’s Health Study. As proxy for SES, we calculated an SES index using annual household income and education. Migraine, migraine aura, and non-migraine headache were self-reported with good validation rates. Multinomial logistic regression models were used to evaluate the association between the SES index and the various headache forms.

Results: Of the women participating in the study, 12,140 (32.9%) reported any history of headache, 6801 (18.4%) reported any history of migraine and 5339 (14.5%) reported non-migraine headache. Women with low SES had an increased risk for all headache forms. The multivariable-adjusted odds ratios (ORs; 95% CI) were 1.22 (1.10–1.36) for non-migraine headache, 1.40 (1.28–1.54) for any migraine, 1.44 (1.23–1.69) for migraine with aura, and 1.38 (1.21–1.58) for migraine without aura. Among active migraineurs, low SES was associated with an increased OR for ≥weekly attack frequency (1.77, 1.26–2.49).

Conclusions: In this large cohort of female health professionals, low SES was associated with an increased prevalence for all headache forms and an increased migraine attack frequency.
Neuromuscular hamartoma is a possible primary pathology of oculomotor ophthalmoplegic migraine
Authors: Akimoto Jiro , Fukami Shinjiro , Hashimoto Ryo , Haraoka Jo
Published: December 2011

Background: Oculomotor ophthalmoplegic migraine (O-OPM) occurs in many children, and in some cases MRI shows a small mass in the root exit zone (REZ) of the oculomotor nerve. This mass is considered to result from nerve hypertrophy caused by repeated demyelination.

Case results: A 51-year-old man has been on oral medication for O-OPM, which he had from 6 years of age. However, the frequency and intensity of his migraine attacks have gradually increased. Brain magnetic resonance imaging (MRI) revealed a small nodular mass in the REZ of the oculomotor nerve. The mass was initially diagnosed as oculomotor schwannoma and tumor resection was attempted. However, as the mass was tightly adhered to the oculomotor nerve and hemorrhagic, biopsy was performed. The pathological diagnosis was neuromuscular hamartoma.

Conclusion: The small nodular mass in the REZ of the oculomotor nerve may be a hamartoma associated with congenital factors and may possibly be the primary pathology of O-OPM in this case.
Testing peatland testate amoeba transfer functions: Appropriate methods for clustered training-sets
Authors: Payne Richard J , Telford Richard J , Blackford Jeffrey J , Blundell Antony , Booth Robert K , Charman Dan J , Lamentowicz Łukasz , Lamentowicz Mariusz , Mitchell Edward AD , Potts Genevieve , Swindles Graeme T , Warner Barry G , Woodland Wendy
Published: December 2011

Transfer functions are widely used in palaeoecology to infer past environmental conditions from fossil remains of many groups of organisms. In contrast to traditional training-set design with one observation per site, some training-sets, including those for peatland testate amoeba-hydrology transfer functions, have a clustered structure with many observations from each site. Here we show that this clustered design causes standard performance statistics to be overly optimistic. Model performance when applied to independent data sets is considerably weaker than suggested by statistical cross-validation. We discuss the reasons for these problems and describe leave-one-site-out cross-validation and the cluster bootstrap as appropriate methods for clustered training-sets. Using these methods we show that the performance of most testate amoeba-hydrology transfer functions is worse than previously assumed and reconstructions are more uncertain.
Chaotification and optimization design of a nonlinear vibration isolation system
Authors: Li Yingli , Xu Daolin , Fu Yiming , Zhou Jiaxi
Published: December 2011

In this paper, the chaos method for reducing line spectra of the radiated noise of marine vessels is implemented with the application of a control scheme, that is, chaotifing the nonlinear vibration isolation system (VIS) with an external chaotic system, such as the Lorenz system families. The scheme is similar to generalized synchronization of chaos to a considerable degree. Moreover, an implicit performance-index function and optimization strategy are proposed to obtain the optimal control gain for generating chaos with the highest quality. Numerical simulations are carried out and the results confirm the validity and effectiveness of the methods.
The influence of code-mixing and speaker information on perception and assessment of foreign language proficiency: An experimental study
Authors: Berthele Raphael
Published: December 2011

The study draws on different lines of research on the influence of social and other information on the evaluation of language production in school contexts. On the one hand, names or other background information is well known to influence teachers and other gatekeepers’ evaluations, and on the other hand, code-switching and other non-standard features in pupils’ language production are also known to affect assessment outcomes not only of linguistic skills but also of general academic potential. Taking into account these two research traditions, this study investigates the influence of different ethnically marked names and code-switches on teachers’ evaluations of pupils’ oral proficiency in French as a foreign language. Three authentic oral texts were rerecorded once by inserting German words and once without such inserts. Additionally, these samples were presented either as stemming from a bilingual Swiss German native or from a multilingual Swiss-German Serbian boy. A total of 157 future teachers rated the speech samples with respect to different dimensions (fluency, correctness, but also the pupil’s academic potential in general). The analyses provide evidence for positive and negative stereotyping of the Serbian first name, and there is also an unexpected interaction with code-mixing into German: without insertional mixing, the texts with a Balkan name are perceived as being superior, but with such mixing this superiority is lost and turns into significantly lower assessment scores.
ECSASB2 mediates MLL degradation during hematopoietic differentiation
Authors: Wang Jingya , Muntean Andrew G. , Hess Jay L.
Published: December 2011

Mixed lineage leukemia (MLL) is a key epigenetic regulator of normal hematopoietic development and chromosomal translocations involving MLL are one of the most common genetic alterations in human leukemia. Here we show that ASB2, a component of the ECSASB E3 ubiquitin ligase complex, mediates MLL degradation through interaction with the PHD/Bromodomain region of MLL. Forced expression of ASB2 degrades MLL and reduces MLL transactivation activity. In contrast, the MLL-AF9 fusion protein does not interact with ASB2 and is resistant to ASB2 mediated degradation. Increased expression of ASB2 during hematopoietic differentiation is associated with decreased levels of MLL protein and down-regulation of MLL target genes. Knockdown of ASB2 leads to increased expression of HOXA9 and delayed cell differentiation. Our data support a model whereby ASB2 contributes to hematopoietic differentiation, in part, through MLL degradation and HOX gene down-regulation. Moreover, deletion of the PHD/Bromo region renders MLL fusion proteins resistant to ASB2-mediated degradation and may contribute to leukemogenesis.
Development of a cultivation process for the enhancement of human interferon alpha 2b production in the oleaginous yeast, Yarrowia lipolytica
Authors: Gasmi Najla , Ayed Atef , Ammar Billel BelHadj , Zrigui Rim , Nicaud Jean-Marc , Kallel Héla
Published: December 2011

Background

As an oleaginous yeast, Yarrowia lipolytica is able to assimilate hydrophobic substrates. This led to the isolation of several promoters of key enzymes of this catabolic pathway. Less is known about the behavior of Y. lipolytica in large bioreactors using these substrates. There is therefore a lack of established know-how concerning high cell density culture protocols of this yeast. Consequently, the establishment of suitable induction conditions is required, to maximize recombinant protein production under the control of these promoters.

Results

Human interferon α2b (huIFN α2b) production in Yarrowia lipolytica was used as a model for the enhancement of recombinant protein production under the control of the oleic acid (OA)-inducible promoter POX2. Cell viability and heterologous protein production were enhanced by exponential glucose feeding, to generate biomass before OA induction. The optimal biomass level before induction was determined (73 g L-1), and glucose was added with oleic acid during the induction phase. Several oleic acid feeding strategies were assessed. Continuous feeding with OA at a ratio of 0.02 g OA per g dry cell weight increased huIFNα2b production by a factor of 1.88 (425 mg L-1) and decreased the induction time (by a factor of 2.6, 21 h). huIFN α2b degradation by an aspartic protease secreted by Y. lipolytica was prevented by adding pepstatin (10 μM), leading to produce a 19-fold more active huIFN α2b (26.2 × 107 IU mg-1).

Conclusion

Y. lipolytica, a generally regarded as safe (GRAS) microorganism is one of the most promising non conventional yeasts for the production of biologically active therapeutic proteins under the control of hydrophobic substrate-inducible promoter.
A nanoporous interferometric micro-sensor for biomedical detection of volatile sulphur compounds
Authors: Kumeria Tushar , Parkinson Luke , Losic Dusan
Published: December 2011

This work presents the use of nanoporous anodic aluminium oxide [AAO] for reflective interferometric sensing of volatile sulphur compounds and hydrogen sulphide [H2S] gas. Detection is based on changes of the interference signal from AAO porous layer as a result of specific adsorption of gas molecules with sulphur functional groups on a gold-coated surface. A nanoporous AAO sensing platform with optimised pore diameters (30 nm) and length (4 µm) was fabricated using a two-step anodization process in 0.3 M oxalic, followed by coating with a thin gold film (8 nm). The AAO is assembled in a specially designed microfluidic chip supported with a miniature fibre optic system that is able to measure changes of reflective interference signal (Fabry-Perrot fringes). When the sensor is exposed to a small concentration of H2S gas, the interference signal showed a concentration-dependent wavelength shifting of the Fabry-Perot interference fringe spectrum, as a result of the adsorption of H2S molecules on the Au surface and changes in the refractive index of the AAO. A practical biomedical application of reflectometric interference spectroscopy [RIfS] Au-AAO sensor for malodour measurement was successfully shown. The RIfS method based on a nanoporous AAO platform is simple, easy to miniaturise, inexpensive and has great potential for development of gas sensing devices for a range of medical and environmental applications.
Mutations affecting interaction of integrase with TNPO3 do not prevent HIV-1 cDNA nuclear import
Authors: Cribier Alexandra , Ségéral Emmanuel , Delelis Olivier , Parissi Vincent , Simon Aurélie , Ruff Marc , Benarous Richard , Emiliani Stéphane
Published: December 2011

Background

Integration of human immunodeficiency virus type 1 (HIV-1) into a host cell chromosome is an essential step under the control of the viral integrase (IN). Although this enzyme is necessary and sufficient to catalyze the integration reactionin vitro, cellular cofactors are involved in the processin vivo. The chromatin-associated factor LEDGF/p75 interacts with IN and promotes integration to transcription units of the host genome. HIV-1 IN also binds the karyopherin TNPO3, however the significance of this interaction during viral replication remains to be explored.

Results

Here we present a functional analysis of IN mutants impaired for LEDGF/p75 and TNPO3 interaction. Among them, IN W131A and IN Q168L, that were previously identified to be deficient for LEDGF/p75 interaction, were also partially impaired for TNPO3 binding. We observed that mutations abolishing IN ability to form tetramers resulted in a severe reduction in LEDGF/p75 binding. In sharp contrast, no correlation could be found between the ability of IN to multimerize and TNPO3 interaction. Most of the mutant viruses were essentially impaired for the integration step whereas the amount of 2-LTR circles, reflecting the nuclear import of the viral DNA, was not significantly affected.

Conclusion

Our functional analysis of HIV-1 IN mutants reveals distinct structural basis for TNPO3 interaction and suggests that the interaction between IN and TNPO3 is not a major determinant of nuclear import but could take place at a nuclear step prior to integration.
The interaction between the PARP10 protein and the NS1 protein of H5N1 AIV and its effect on virus replication
Authors: Yu Mengbin , Zhang Chuanfu , Yang Yutao , Yang Zhixin , Zhao Lixia , Xu Long , Wang Rong , Zhou Xiaowei , Huang Peitang
Published: December 2011

Background

During the process that AIV infect hosts, the NS1 protein can act on hosts, change corresponding signal pathways, promote the translation of virus proteins and result in virus replication.

Results

In our study, we found that PARP domain and Glu-rich region of PARP10 interacted with NS1, and the presence of NS1 could induce PARP10 migrate from cytoplasm to nucleus. NS1 high expression could reduce the endogenous PARP10 expression. Cell cycle analysis showed that with inhibited PARP10 expression, NS1 could induce cell arrest in G2-M stage, and the percentage of cells in G2-M stage rise from the previous 10%-45%, consistent with the cell proliferation result. Plague forming unit measurement showed that inhibited PARP10 expression could help virus replication.

Conclusions

In a word, our results showed that NS1 acts on host cells and PARP10 plays a regulating role in virus replication.
Multi-Country analysis of palm oil consumption and cardiovascular disease mortality for countries at different stages of economic development: 1980-1997
Authors: Chen Brian K , Seligman Benjamin , Farquhar John W , Goldhaber-Fiebert Jeremy D
Published: December 2011

Background

Cardiovascular diseases represent an increasing share of the global disease burden. There is concern that increased consumption of palm oil could exacerbate mortality from ischemic heart disease (IHD) and stroke, particularly in developing countries where it represents a major nutritional source of saturated fat.

Methods

The study analyzed country-level data from 1980-1997 derived from the World Health Organization's Mortality Database, U.S. Department of Agriculture international estimates, and the World Bank (234 annual observations; 23 countries). Outcomes included mortality from IHD and stroke for adults aged 50 and older. Predictors included per-capita consumption of palm oil and cigarettes and per-capita Gross Domestic Product as well as time trends and an interaction between palm oil consumption and country economic development level. Analyses examined changes in country-level outcomes over time employing linear panel regressions with country-level fixed effects, population weighting, and robust standard errors clustered by country. Sensitivity analyses included further adjustment for other major dietary sources of saturated fat.

Results

In developing countries, for every additional kilogram of palm oil consumed per-capita annually, IHD mortality rates increased by 68 deaths per 100,000 (95% CI [21-115]), whereas, in similar settings, stroke mortality rates increased by 19 deaths per 100,000 (95% CI [-12-49]) but were not significant. For historically high-income countries, changes in IHD and stroke mortality rates from palm oil consumption were smaller (IHD: 17 deaths per 100,000 (95% CI [5.3-29]); stroke: 5.1 deaths per 100,000 (95% CI [-1.2-11.0])). Inclusion of other major saturated fat sources including beef, pork, chicken, coconut oil, milk cheese, and butter did not substantially change the differentially higher relationship between palm oil and IHD mortality in developing countries.

Conclusions

Increased palm oil consumption is related to higher IHD mortality rates in developing countries. Palm oil consumption represents a saturated fat source relevant for policies aimed at reducing cardiovascular disease burdens.
Spinal radiosurgery - efficacy and safety after prior conventional radiotherapy
Authors: Nikolajek Katharina , Kufeld Markus , Muacevic Alexander , Wowra Berndt , Niyazi Maximilian , Ganswindt Ute
Published: December 2011

Background

Conventional external beam radiotherapy is a standard procedure for treatment of spinal metastases. In case of progression spinal cord tolerance limits further radiotherapy in pre-irradiated areas. Spinal stereotactic radiotherapy is a non-invasive option to re-treat pre-irradiated patients. Nevertheless, spinal radiosurgery results in relevant dose deposition within the myelon with potential toxicity. Aim of the study was to retrospectively analyse the efficacy and feasibility for salvage radiosurgery of spinal metastases.

Methods

During a period of 4 years (2005-2009) 70 lesions in 54 patients were treated in 60 radiosurgery sessions and retrospectively analysed. Clinical (pain, sensory and motor deficit) and radiological (CT/MRI) follow-up data were collected prospectively after radiosurgery. Pain - as main symptom - was classified by the Visual Analogue Scale (VAS) score. Every patient received single session radiosurgery after having been treated first-line with conventionally fractionated radiotherapy. Kaplan-Meier method and life tables were used to analyse freedom from local failure and overall survival.

Results

At a median follow-up of 14.5 months the actuarial rates of freedom from local failure at 6/12/18 months were 93%, 88% and 85%, respectively. The median radiosurgery dose was 1 × 18 Gy (range 10-28 Gy) to the median 70% isodose. The VAS score of patients with pain (median 6) dropped significantly (median 4, p = 0.002). In 6 out of 7 patients worse sensory or motor deficit after SRS was caused by local or distant failures (diagnosed by CT/MRI). One patient with metastatic renal cell carcinoma developed a progressive complete paraparesis one year after the last treatment at lumbar level L3. Due to multiple surgery and radiosurgery treatments at the lumbar region and further local progression, the exact reason remained unclear. Apart from that, no CTC grade III or higher toxicity has been observed.

Conclusions

By applying spinal radiosurgery relevant radiation doses can be limited to small parts of the myelon. This prevents myelopathic side effects and makes it an effective and safe treatment option for well-suited patients. Especially for previously irradiated patients with local failure or pain salvage SRS represents a valuable treatment option with high local control rates, low toxicity and significant pain reduction.
Coalescence theory for a general class of structured populations with fast migration
Authors: Hössjer O.
Published: December 2011

In this paper we study a general class of population genetic models where the total population is divided into a number of subpopulations or types. Migration between subpopulations is fast. Extending the results of Nordborg and Krone (2002) and Sagitov and Jagers (2005), we prove, as the total population sizeNtends to ∞, weak convergence of the joint ancestry of a given sample of haploid individuals in the Skorokhod topology towards Kingman's coalescent with a constant change of time scalec. Our framework includes age-structured models, geographically structured models, and combinations thereof. We also allow each individual to have offspring in several subpopulations, with general dependency structures between the number of offspring of various types. As a byproduct, explicit expressions for the coalescent effective population sizeN/care obtained.
On approximative solutions of optimal stopping problems
Authors: Faller Andreas , Rüschendorf Ludger
Published: December 2011

In this paper we establish an extension of the method of approximating optimal discrete-time stopping problems by related limiting stopping problems for Poisson-type processes. This extension allows us to apply this method to a larger class of examples, such as those arising, for example, from point process convergence results in extreme value theory. Furthermore, we develop new classes of solutions of the differential equations which characterize optimal threshold functions. As a particular application, we give a fairly complete discussion of the approximative optimal stopping behavior of independent and identically distributed sequences with discount and observation costs.
Tail behavior of multivariate lévy-driven mixed moving average processes and supOU Stochastic Volatility Models
Authors: Moser Martin , Stelzer Robert
Published: December 2011

Multivariate Lévy-driven mixed moving average (MMA) processes of the type Xt = ∬f(A, t - s)Λ(dA, ds) cover a wide range of well known and extensively used processes such as Ornstein-Uhlenbeck processes, superpositions of Ornstein-Uhlenbeck (supOU) processes, (fractionally integrated) continuous-time autoregressive moving average processes, and increments of fractional Lévy processes. In this paper we introduce multivariate MMA processes and give conditions for their existence and regular variation of the stationary distributions. Furthermore, we study the tail behavior of multivariate supOU processes and of a stochastic volatility model, where a positive semidefinite supOU process models the stochastic volatility.
Sensitivity Analysis in Markov Decision Processes with Uncertain Reward Parameters
Authors: Tan Chin Hon , Hartman Joseph C.
Published: December 2011

Sequential decision problems can often be modeled as Markov decision processes. Classical solution approaches assume that the parameters of the model are known. However, model parameters are usually estimated and uncertain in practice. As a result, managers are often interested in how estimation errors affect the optimal solution. In this paper we illustrate how sensitivity analysis can be performed directly for a Markov decision process with uncertain reward parameters using the Bellman equations. In particular, we consider problems involving (i) a single stationary parameter, (ii) multiple stationary parameters, and (iii) multiple nonstationary parameters. We illustrate the applicability of this work through a capacitated stochastic lot-sizing problem.
Small-Time Asymptotics of Option Prices and First Absolute Moments
Authors: Muhle-Karbe Johannes , Nutz Marcel
Published: December 2011

We study the leading term in the small-time asymptotics of at-the-money call option prices when the stock price process S follows a general martingale. This is equivalent to studying the first centered absolute moment of S. We show that if S has a continuous part, the leading term is of order √T in time T and depends only on the initial value of the volatility. Furthermore, the term is linear in T if and only if S is of finite variation. The leading terms for pure-jump processes with infinite variation are between these two cases; we obtain their exact form for stable-like small jumps. To derive these results, we use a natural approximation of S so that calculations are necessary only for the class of Lévy processes.
On the Monitoring Error of the Supremum of a Normal Jump Diffusion Process
Authors: Chen Ao , Feng Liming , Song Renming
Published: December 2011

We derive an expansion for the (expected) difference between the continuously monitored supremum and evenly monitored discrete maximum over a finite time horizon of a jump diffusion process with independent and identically distributed normal jump sizes. The monitoring error is of the form a0 / N1/2 + a1 / N3/2 + · · · + b1 / N + b2 / N2 + b4 / N4
+ · · ·, where N is the number of monitoring intervals. We obtain explicit expressions for the coefficients {a0, a1, …, b1, b2, …}. In particular, a0 is proportional to the value of the Riemann zeta function at ½, a well-known fact that has been observed for Brownian motion in applied probability and mathematical finance.
Convergence Properties in Certain Occupancy Problems Including the Karlin-Rouault Law
Authors: Khmaladze Estáte V.
Published: December 2011

Let x denote a vector of length q consisting of 0s and 1s. It can be interpreted as an ‘opinion’ comprised of a particular set of responses to a questionnaire consisting of q questions, each having {0, 1}-valued answers. Suppose that the questionnaire is answered by n individuals, thus providing n ‘opinions’. Probabilities of the answer 1 to each question can be, basically, arbitrary and different for different questions. Out of the 2q different opinions, what number, μn, would one expect to see in the sample? How many of these opinions, μn(k), will occur exactly k times? In this paper we give an asymptotic expression for μn / 2q and the limit for the ratios μn(k)/μn, when the number of questions q increases along with the sample size n so that n = λ2q, where λ is a constant. Let p(x) denote the probability of opinion x. The key step in proving the asymptotic results as indicated is the asymptotic analysis of the joint behaviour of the intensities np(x). For example, one of our results states that, under certain natural conditions, for any z > 0, ∑1{np(x) > z} = dnz−u,
dn = o(2q).
Using the Electronic Medical Record to Better Define “No Products of Conception” as a Critical Value in Anatomic Pathology
Authors: Renshaw Andrew
Published: December 2011

At present, the College of American Pathologists checklist requires documentation of communication of critical values in anatomic pathology to caregivers. Recently, our institution has begun using the electronic medical record to document the lack of imminent danger or emergency associated with the case rather than calling the caregiver. I sought to document this trend.

The results of all critical values and all endometrial curettings with a diagnosis of “no products of conception seen” for the last 3 years at 1 hospital were reviewed. During the first 18 months, 0 of 11 critical cases were documented by reference to the electronic medical record. During the second 18 months 5 of 14 cases (36%; P = .02) were documented to have an intrauterine pregnancy by ultrasound and the physician was not notified. In our laboratory, cases without products of conception and a documented intrauterine pregnancy are no longer considered critical values in anatomic pathology.

Documentation of the lack of imminent danger to the patient through reference to the electronic medical record is an increasingly common and acceptable means of ensuring patient safety and more accurately defining critical values in anatomic pathology.
Avaliação da partida e operação de filtros anaeróbios tendo bambu como material de recheio
Authors: Tonetti Adriano Luiz , Coraucci Filho Bruno , Guimarães José Roberto , Cruz Luana Mattos de Oliveira , Nakamura Marcela Soliz
Published: December 2011

Neste trabalho, foram constituídos três filtros anaeróbios com volume de 500 L preenchidos com anéis de bambu, operando-os com tempo de detenção hidráulica de nove horas. O objetivo foi a determinação do período de partida sem o emprego de inóculo adaptado e a obtenção da eficiência no tratamento de esgoto doméstico, empregando-se um tempo de detenção hidráulica inferior às 12 horas sugeridas pela NBR 7229. Na avaliação do sistema, fez-se uso do carbono orgânico dissolvido, da demanda química de oxigênio, da demanda bioquímica de oxigênio, pH e alcalinidade, evidenciando quanto ao carbono orgânico dissolvido, a necessidade de 19 semanas para que se alcançasse o equilíbrio dinâmico nos reatores. Após esse período, a remoção atingiu 81,4 ± 6,4%. Os resultados demonstraram que o uso de um recheio alternativo nos filtros anaeróbios possibilitou uma eficiência similar a encontrada com materiais tradicionais, mesmo adotando-se um tempo de detenção hidráulica inferior ao indicado pela norma brasileira.
Quantifying the Results of Horizontal Multistage Development in Tight Oil Reservoirs of the Western Canadian Sedimentary Basin: Technical and Economic Case Studies From a Reservoir Evaluator’s Perspective
Authors: Hamm Brian , Struyk Eric
Published: December 2011

Recent advances in horizontal drilling and multistage completion technologies have unlocked vast quantities of previously inaccessible oil reserves. Since 2006, thousands of horizontal multistage wells have been drilled into numerous low permeability oil reservoirs in the Western Canadian Sedimentary Basin including the Bakken, Cardium, Viking and Shaunavon formations. Early horizontal multistage wells had relatively short horizontal sections with two to four completion stages per well and have evolved over time to include wells in certain areas that have up to two mile horizontal sections and over 25 individual completion stages. Along with the technical advancements that have occurred recently, operators are actively seeking new reservoirs in which to apply them.

This paper presents a brief historical look back at a few of the major areas that have been developed to date. Specifically, the light oil developments of the Bakken formation in Saskatchewan, Manitoba and North Dakota, the Cardium formation in Alberta, the Viking formation in Alberta and Saskatchewan and the Lower Shaunavon formation in Saskatchewan are studied in detail and comparisons drawn. Type curves are presented by vintage for each play showing the progression of advancing technology countered by operator desire to push the development into reservoir of diminishing quality. Specific technical metrics regarding initial production rates and decline rates are compared and contrasted. Average expected ultimate recoveries are estimated based on decline analysis and the authors experience completing detailed reserve evaluations for operators in their respective development areas. Based on the statistical study of performance to date and the estimates of ultimate recovery a type well based on current development is generated for each of the areas.

Economic modeling based on the generated type wells and a comparison of the various development areas is presented using a number of financial and industry metrics. Despite vast differences in productivity and recovery per well between the plays, the economic analysis reveals that bigger is not necessarily better.
A Study Examining Coupled Geomechanics and Reservoir Fluid Flow Modelling
Authors: Gu Edward Wei , Sammon Peter , Da Costa Alvaro Maia , Cabral Leonardo , de Souza Luis Carlos , Pao William
Published: December 2011

A comparative study was carried out examining some coupled geomechanics and reservoir fluid flow simulations. The study attempted to answer the questions: "Why do we need coupled geomechanics and reservoir fluid flow analyses" and "How do we do the coupled work"? It is common in reservoir engineering to expect that volumetric deformation in the reservoir may change rock properties such as porosity and permeability, and hence change reservoir flows. However, the effects of shear or deviatory deformation, and stress re-distribution in the reservoir, on the fluid flow have been often neglected. These latter effects will be examined in this paper.

This paper clarifies the notion that shear or non-uniform deformation and stress re-distribution in the reservoir may have significant effects on reservoir fluid flows. Thus, a "fully" coupled or "two-way" coupled analysis is a "must have" approach in a reservoir study where the shear deformation or changes in total stresses in the reservoir can not be ignored. Shear deformation or changes in total stresses, and the resulting stress re-distribution in the reservoir, can be caused by non-uniform reservoir flows; boundary, corner and arching constraints; material nonlinearity; sliding along interfaces or faults; irregular reservoir geometry; among other causes leading to non-uniform deformations.

There are only a few cases in which a reservoir flow analysis can be conducted independently, i.e., without coupled geomechanical calculations, such as when the reservoir flow is occurring under uniaxial deformation or isotropic deformation conditions. The compressibility of the rock phase in these uncoupled reservoir flow simulations has to be selected with caution according to the deformation pattern that will occur in the reservoir. In the cases where no simple deformation pattern can be defined, a "fully" or "two-way" coupled geomechanical analysis has to be conducted along with the reservoir flow analysis. Otherwise, significant errors may occur in prediction of reservoir performance, not only for reservoir deformation, but also for reservoir fluid flows.
Design of Solvent-Assisted SAGD Processes in Heterogeneous Reservoirs Using Hybrid Optimization Techniques
Authors: Al-Gosayir Muhammad , Leung Juliana , Babadagli Tayfun
Published: December 2011

Many Steam Assisted Gravity Drainage (SAGD) optimization studies published in the literature combined numerical simulation with graphical or analytical techniques for design and performance evaluation. There have been numerous efforts that integrated the simulation exercise with global optimization algorithms. Some studies focused on optimization of cumulative steam-to-oil ratio (cSOR) in SAGD by altering steam injection rates, while others focused on optimization of cumulative net energy-to-oil ratio (cEOR) in solvent-additive SAGD by altering injection pressures and fraction of solvent in the injection stream. Several studies also considered total project net present value calculation by changing total project area, capital cost intensities, solvent prices, and risk factors to determine the well spacing and drilling schedule. Optimization techniques commonly used in those studies were scattered search, simulated annealing, and genetic algorithm (GA). However, the applications of hybrid genetic algorithm were rarely found.

In this paper, we focused on optimization of solvent-assisted SAGD using various GA implementations. In our models, hexane was selected to be co-injected with steam. The objective function, defined based on cumulative steam-oil ratio (cSOR) and recovery factor, was optimized by changing injection pressures, production pressures, and injected solvent-to-steam ratio. Techniques including orthogonal arrays (OA) for experimental design (e.g. Taguchi’s arrays) and proxy models for objective function evaluations were incorporated with the GA method to improve computational and convergence efficiency. Results from these hybrid approaches revealed that an optimized solution could be achieved with less CPU time (e.g. fewer number of iterations) compared to the conventional GA method. Sensitivity analysis was also conducted on the choice of proxy model to study the robustness of the proposed methods.

To investigate the effects of heterogeneity in the design process, optimization of solvent-assisted SAGD was performed on various synthetic heterogeneous reservoir models of porosity, permeability, and shale distributions. Our results highlight the potential application of the proposed techniques in other solvent-enhanced heavy oil recovery processes.