bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanostructured materials with biomimetic recognition abilities for chemical sensing
Authors: Bajwa Sadia Zafar , Mustafa Ghulam , Samardzic Renata , Wangchareansak Thipvaree , Lieberzeit Peter A
Published: September 2012

Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The ‘harder’ MoS2 yields only about 40% of the signals towards octane thiol as compared to the ‘softer’ Cu2S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.
Characterization of fatty acid modifying enzyme activity in staphylococcal mastitis isolates and other bacteria
Authors: Lu Thea , Park Joo Youn , Parnell Kelleen , Fox Larry K , McGuire Mark A
Published: September 2012

Background

Fatty acid modifying enzyme (FAME) has been shown to modify free fatty acids to alleviate their bactericidal effect by esterifying fatty acids to cholesterol or alcohols. Although it has been shown in previous studies that FAME is required forStaphylococcus aureussurvival in skin abscesses, FAME is poorly studied compared to other virulence factors. FAME activity had also been detected in coagulase-negative staphylococci (CNS). However, FAME activity was only surveyed after a bacterial culture was grown for 24 h. Therefore if FAME activity was earlier in the growth phase, it would not have been detected by the assay and those strains would have been labeled as FAME negative.

Results

Fifty CNS bovine mastitis isolates and severalS. aureus, Escherichia coli, andStreptococcus uberisstrains were assayed for FAME activity over 24 h. FAME activity was detected in 54% of CNS and 80% S. aureusstrains surveyed but none inE. coliorS. uberis. While some CNS strains produced FAME activity comparable to the lab strain ofS. aureus, the pattern of FAME activity varied among strains and across species of staphylococci. All CNS that produced FAME activity also exhibited lipase activity. Lipase activity relative to colony forming units of these CNS decreased over the 24 h growth period. No relationship was observed between somatic cell count in the milk and FAME activity in CNS.

Conclusions

Some staphylococcal species surveyed produced FAME activity, butE. coliandS. uberisstrains did not. All FAME producing CNS exhibited lipase activity which may indicate that both these enzymes work in concert to alter fatty acids in the bacterial environment.
Use of cognitive enhancers for mild cognitive impairment: protocol for a systematic review and network meta-analysis
Authors: Tricco Andrea C , Soobiah Charlene , Lillie Erin , Perrier Laure , Chen Maggie H , Hemmelgarn Brenda , Majumdar Sumit R , Straus Sharon E
Published: September 2012

Background

Elderly individuals who have memory problems without significant limitations in activities of daily living are often diagnosed as having mild cognitive impairment (MCI). Some of these individuals progress to dementia. Several cognitive enhancers (for example donepezil, galantamine, rivastigmine, memantine) have been approved for use in people with Alzheimer’s dementia but their use in patients with MCI is unclear. We aimed to determine the comparative effectiveness, safety, and cost of cognitive enhancers for MCI through a systematic review and network (that is, indirect comparisons) meta-analysis.

Design/Methods

We will include studies that examine the use of cognitive enhancers compared to placebo, supportive care, or other cognitive enhancers among patients diagnosed with MCI. Outcomes of interest include cognition and function (primary outcomes), as well as behavior, quality of life, safety, and cost (secondary outcomes). We will include all experimental studies (randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials), quasi-experimental studies (controlled before-after, interrupted time series), and observational studies (cohort, case–control). Studies will be included regardless of publication status (that is, we will include unpublished studies), year, or language of dissemination.

To identify potentially relevant material, we will search the following electronic databases from inception onwards: MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, and Ageline. The electronic database search will be supplemented by scanning the reference lists of included studies, searching Google and organization websites for unpublished or difficult to locate material literature, and contacting experts.

Two reviewers will independently screen the studies for inclusion using the eligibility criteria established a priori and independently extract data. Risk of bias will be assessed using the Cochrane Risk of Bias tool for experimental and quasi-experimental studies and the Newcastle Ottawa Scale for observational epidemiology studies. Meta-analysis and network meta-analysis are planned, if the studies are deemed statistically, methodologically, and clinically homogenous.

Discussion

Our systematic review will provide important information regarding the benefits, costs, and harms of cognitive enhancers for patients with MCI. This information can be used to assist healthcare providers, policy-makers, MCI patients and their family regarding the use of these agents.

PROSPERO registry number

CRD42012002234
Analysis of variation at transcription factor binding sites in Drosophila and humans
Authors: Spivakov Mikhail , Akhtar Junaid , Kheradpour Pouya , Beal Kathryn , Girardot Charles , Koscielny Gautier , Herrero Javier , Kellis Manolis , Furlong Eileen EM , Birney Ewan
Published: September 2012

Background

Advances in sequencing technology have boosted population genomics and made it possible to map the positions of transcription factor binding sites (TFBSs) with high precision. Here we investigate TFBS variability by combining transcription factor binding maps generated by ENCODE, modENCODE, our previously published data and other sources with genomic variation data for human individuals and Drosophila isogenic lines.

Results

We introduce a metric of TFBS variability that takes into account changes in motif match associated with mutation and makes it possible to investigate TFBS functional constraints instance-by-instance as well as in sets that share common biological properties. We also take advantage of the emerging per-individual transcription factor binding data to show evidence that TFBS mutations, particularly at evolutionarily conserved sites, can be efficiently buffered to ensure coherent levels of transcription factor binding.

Conclusions

Our analyses provide insights into the relationship between individual and interspecies variation and show evidence for the functional buffering of TFBS mutations in both humans and flies. In a broad perspective, these results demonstrate the potential of combining functional genomics and population genetics approaches for understanding gene regulation.
The dual roles of inflammatory cytokines and chemokines in the regulation of autoimmune diseases and their clinical implications
Authors: Shachar Idit , Karin Nathan
Published: September 2012

Review of pro- and anti-inflammatory cytokines, and their dependence on the local concentration of a given cytokine, the stage of disease in which it is administered, and its combination with other cytokines.

Cytokines and chemokines are secreted, small cell-signaling protein molecules, whose receptors are expressed on immune cells. These factors play a critical role in immune cell differentiation, migration, and polarization into functional subtypes and in directing their biological functions. Much attention has been devoted to exploring the role of key inflammatory cytokines and promigratory chemokines in autoimmune, autoinflammatory, and allergic diseases, leading to development of therapeutic strategies that are based on their targeted neutralization. Recent studies, including those coming from our groups, show that several major proinflammatory cytokines and chemokines, including IFN-γ, IL-2, CCL2, and CXCL12, may also function as anti-inflammatory mediators and therefore, may have potential as anti-inflammatory drugs. Likewise, major anti-inflammatory mediators, such as TGF-β, may under certain conditions, in combination with other cytokines, exhibit proinflammatory function and direct the polarization of the highly inflammatory CD4+ Th17 cells. We show here that the biological function of pro- and anti-inflammatory cytokines is dependent on three key parameters: the local concentration of a given cytokine, the stage of disease in which it is administered, and its combination with other cytokines. The therapeutic implications of these findings are discussed, including two very recent studies summarizing clinical trials, in which low-dose administration of IL-2 was used to successfully suppress HCV and GVHD.
An introduction to this special section: Geophysics in reserves estimation
Authors: Lorenzen Robert , Kloosterman Henk Jaap , Abriel William
Published: September 2012

Estimating oil and gas reserves is one of the most important functions for petroleum companies to support portfolio management and revenue forecasting. The investment com-munity uses reported reserves to assign values to companies or to individual projects, which is important to the stock markets and for financing projects. Governments use reported reserves for regulatory oversight and for forecasting national petroleum production. In 2008, one of those government agencies, the U.S. Securities and Exchange Commission (SEC), published “Modernization of Oil and Gas Reporting.” The document was based on numerous recommendations to update reporting rules for oil and gas companies to reflect the advance in technologies.
The role of geophysics in petroleum resources estimation and classification—new industry guidance and best practices
Authors: Kloosterman Henk Jaap , Pichon Pierre-Louis
Published: September 2012

Geophysical technologies can have an impact on both the uncertainty axis as well as the maturity axis of the resource classification framework described in the Petroleum Resources Management System (PRMS). For conventional resources, the technical maturity of a project can be significantly impacted by applying geophysical technologies for assessing structural definition, reservoir development, fluid contacts and movements, and for flow surveillance. For unconventional resources, the largest uncertainties to date are on efficient extraction, an area where geophysical technologies have so far mainly played a supporting role. Geophysical technologies also may contribute to the definition of the range of the low, best, and high resource volume estimates.
Resource assessment based on 4D seismic and inversion at Ringhorne Field, Norwegian North Sea
Authors: Johnston David H. , Laugier Bernard P.
Published: September 2012

Time-lapse (4D) seismic data from Ringhorne Field in the North Sea are used to monitor water movement in both Paleocene- and Jurassic-age reservoir sands, improve existing geologic and simulation models, and enable more cost-effective field operations. The structural complexity of the reservoirs, their proximity to the high-impedance Cretaceous chalk, and a relatively small 4D response has required a significant effort in seismic acquisition and processing which resulted in highly repeatable surveys (Johnston et al., 2010). In addition to the 4D interpretation, VP/VS derived from simultaneous elastic inversion is diagnostic of sand and provides additional constraints on Ringhorne subsurface models. Connected volumes based on VP/VS correlate to areas of water sweep seen in the 4D data and reduce uncertainty in 4D interpretation. Relative P-wave impedance changes calculated from inversion are consistent with presurvey 4D predictions. The 4D seismic data and inversion help explain water breakthrough timing, improve our understanding of field production history, and have resulted in the identification of additional infill well opportunities.
Relating seismic interpretation to reserve/resource calculations: Insights from a DHI consortium
Authors: Roden Rocky , Forrest Mike , Holeywell Roger
Published: September 2012

In the process of quantifying resources/reserves, geoscientists attempt to employ all the available pertinent information to produce the most accurate results. The presence of direct hydrocarbon indicators (DHI) on seismic data can have a significant impact on the reserve/resource calculations not only for volumes, but also uncertainty levels. In 2001 a consortium of oil companies was organized in an attempt to understand seismic amplitude anomalies interpreted as DHIs and their impact on prospect risking and resource calculations (Roden et al., 2005; Forrest et al., 2010). The geologic setting, seismic and rock physics data quality, DHI characteristics, and calibration of drilling results are all incorporated into a database in a consistent and systematic process. From this process, the evaluation of 217 prospects and associated well results has enabled an in-depth understanding of the relevant key aspects of seismic amplitude anomalies and how they relate to drilling results.
Stochastic volume estimation and connectivity analysis at the Mallik gas hydrate field, Northwest Territories, Canada
Authors: Dubreuil-Boisclair Camille , Gloaguen Erwan , Bellefleur Gilles , Marcotte Denis
Published: September 2012

Gas hydrates located offshore and onshore beneath thick permafrost areas constitute one of the largest untapped natural gas resources. Yet, gas hydrate in place (GHIP) estimation at the scale of a field is not common in the scientific literature but is required to realistically assess the economical potential of specific accumulations. Progress in the last decade in Alaska and Canada has shown that gas hydrate accumulations beneath thick permafrost can be mapped at depth using conventional seismic attributes (Inks et al., 2009; Riedel et al. 2009). To evaluate the economic potential of gas hydrates in this environment, a test site at Mallik, Northwest Territories, Canada, was extensively surveyed (three-dimensional seismic, full set of logs in two wells, etc.) and a production test was realized in high gas-hydrate horizons. At Mallik, high P- and S-wave velocities, high acoustic impedances, and strong seismic amplitude reflections were all linked to sand-rich sediments with a high saturation of gas hydrates (Bellefleur et al. 2006; Riedel et al.). This relationship provides a strong basis for an integrated data characterization of this gas hydrate deposit.
Case study: Using seismic inversion to constrain “proved area” definition
Authors: Eastley K. , Unstead P. , Kloosterman H. J.
Published: September 2012

At the end of 2008, the U.S. Securities and Exchange Commission (SEC) published new rules regarding the determination of oil and gas reserves. The updated requirements state that the drainage area for the life of the field must be based on all available engineering and geoscience data. This paper presents a recent case study in which seismic data were used extensively in support of the reserves booking.
Long-Term Survivors of Gastric Cancer: A California Population-Based Study
Authors: Kunz Pamela L. , Gubens Matthew , Fisher George A. , Ford James M. , Lichtensztajn Daphne Y. , Clarke Christina A.
Published: September 2012

Purpose

In the United States, gastric cancer is rapidly fatal with a 25% 5-year survival. Of the few patients who survive, little is known about their demographic, clinical, and tumor characteristics.

Patients and Methods

Data regarding all cases of gastric and gastroesophageal junction (GEJ) adenocarcinoma diagnosed in California between 1988 and 2005 were obtained from the California Cancer Registry, a member of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. A Cox proportional hazards model was constructed to understand the independent relationships of patient demographic, disease, and treatment factors with survival.

Results

We identified 47,647 patients diagnosed with gastric or GEJ cancer. Of those, only 9,325 (20%) survived at least 3 years. Variables associated with longer survival were localized stage (hazard ratio [HR], 0.20), surgery with diagnosis in 2002 or later (HR, 0.34), surgery with diagnosis in 2001 or before (0.37), regional stage (HR, 0.53), chemotherapy (HR, 0.56), intestinal histology (HR, 0.74), well- or moderately differentiated tumors (HR, 0.76), radiation (HR, 0.80), Asian/Pacific Islander race (HR, 0.81), treatment at an academic hospital (HR, 0.85), fundus/body/antrum location (HR, 0.90), highest socioeconomic status quintile (HR, 0.91), female sex (HR, 0.92), Hispanic race (HR, 0.92), and hospital size more than 150 beds (HR, 0.94). Kaplan-Meier curves showed longer median disease-specific survival (DSS) in patients with tumors originating in the fundus/body/antrum compared with esophagus/cardia (13.4 v 10.8 months). Intestinal histology had significantly longer median DSS (28.9 months) compared with other (11.0 months) or diffuse (10.1 months) histology.

Conclusion

Patients who survive gastric and GEJ cancer more than 3 years after diagnosis have demographic and pathologic characteristics distinct from those who do not survive.
Biosynthesis of 3-Iodothyronamine (T1AM) Is Dependent on the Sodium-Iodide Symporter and Thyroperoxidase but Does Not Involve Extrathyroidal Metabolism of T4
Authors: Hackenmueller Sarah A. , Marchini Maja , Saba Alessandro , Zucchi Riccardo , Scanlan Thomas S.
Published: September 2012

3-Iodothyronamine (T1AM) is an endogenous thyroid hormone derivative with unknown biosynthetic origins. Structural similarities have led to the hypothesis that T1AM is an extrathyroidal metabolite of T4. This study uses an isotope-labeled T4 [heavy-T4 (H-T4)] that can be distinguished from endogenous T4 by mass spectrometry, which allows metabolites to be identified based on the presence of this unique isotope signature. Endogenous T1AM levels depend upon thyroid status and decrease upon induction of hypothyroidism. However, in hypothyroid mice replaced with H-T4, the isotope-labeled H-T3 metabolite is detected, but no isotope-labeled T1AM is detected. These data suggest that T1AM is not an extrathyroidal metabolite of T4, yet is produced by a process that requires the same biosynthetic factors necessary for T4 synthesis.
Double-Stranded RNA-Activated Protein Kinase Is a Key Modulator of Insulin Sensitivity in Physiological Conditions and in Obesity in Mice
Authors: Carvalho-Filho M. A. , Carvalho B. M. , Oliveira A. G. , Guadagnini D. , Ueno M. , Dias M. M. , Tsukumo D. M. , Hirabara S. M. , Reis L. F. , Curi R. , Carvalheira J. B.C. , Saad Mario J.A.
Published: September 2012

The molecular integration of nutrient- and pathogen-sensing pathways has become of great interest in understanding the mechanisms of insulin resistance in obesity. The double-stranded RNA-dependent protein kinase (PKR) is one candidate molecule that may provide cross talk between inflammatory and metabolic signaling. The present study was performed to determine, first, the role of PKR in modulating insulin action and glucose metabolism in physiological situations, and second, the role of PKR in insulin resistance in obese mice. We used Pkr−/− and Pkr+/+ mice to investigate the role of PKR in modulating insulin sensitivity, glucose metabolism, and insulin signaling in liver, muscle, and adipose tissue in response to a high-fat diet. Our data show that in lean Pkr−/− mice, there is an improvement in insulin sensitivity, and in glucose tolerance, and a reduction in fasting blood glucose, probably related to a decrease in protein phosphatase 2A activity and a parallel increase in insulin-induced thymoma viral oncogene-1 (Akt) phosphorylation. PKR is activated in tissues of obese mice and can induce insulin resistance by directly binding to and inducing insulin receptor substrate (IRS)-1 serine307 phosphorylation or indirectly through modulation of c-Jun N-terminal kinase and inhibitor of κB kinase β. Pkr−/− mice were protected from high-fat diet-induced insulin resistance and glucose intolerance and showed improved insulin signaling associated with a reduction in c-Jun N-terminal kinase and inhibitor of κB kinase β phosphorylation in insulin-sensitive tissues. PKR may have a role in insulin sensitivity under normal physiological conditions, probably by modulating protein phosphatase 2A activity and serine-threonine kinase phosphorylation, and certainly, this kinase may represent a central mechanism for the integration of pathogen response and innate immunity with insulin action and metabolic pathways that are critical in obesity.
Creation and Preliminary Characterization of a Leptin Knockout Rat
Authors: Vaira Sergio , Yang Chang , McCoy Aaron , Keys Kelly , Xue Shurong , Weinstein Edward J. , Novack Deborah V. , Cui Xiaoxia
Published: September 2012

Leptin, a cytokine-like hormone secreted mainly by adipocytes, regulates various pathways centered on food intake and energy expenditure, including insulin sensitivity, fertility, immune system, and bone metabolism. Here, using zinc finger nuclease technology, we created the first leptin knockout rat. Homozygous leptin null rats are obese with significantly higher serum cholesterol, triglyceride, and insulin levels than wild-type controls. Neither gender produced offspring despite of repeated attempts. The leptin knockout rats also have depressed immune system. In addition, examination by microcomputed tomography of the femurs of the leptin null rats shows a significant increase in both trabecular bone mineral density and bone volume of the femur compared with wild-type littermates. Our model should be useful for many different fields of studies, such as obesity, diabetes, and bone metabolism-related illnesses.
Expression of the Ring Ligase PRAJA2 in Thyroid Cancer
Authors: Cantara Silvia , D'Angeli Francesco , Toti Paolo , Lignitto Luca , Castagna Maria Grazia , Capuano Serena , Prabhakar Bellur S. , Feliciello Antonio , Pacini Furio
Published: September 2012

Introduction:

In thyroid cells, binding of TSH to its receptor increases cAMP levels, sustaining thyrocytes growth and hormone production. The main cAMP effector enzyme is protein kinase A (PKA). Praja2 is a widely expressed RING (Really Interesting New Gene) ligase, which degrades the regulatory subunits of PKA, thus controlling the strength and duration of PKA signaling in response to cAMP. Differentiated thyroid cancer expresses a functional TSH receptor, and its growth and progression are positively regulated by TSH and cAMP signaling.

Aim:

We aimed to analyze the expression of praja2 in a group of 36 papillary thyroid cancer (PTC), 14 benign nodules, and six anaplastic thyroid cancers (ATC).

Methods:

We measured praja2 mRNA levels by quantitative RT-PCR and praja2 expression by Western blot and immunohistochemistry. Possible association between praja2 mRNA and the presence of known mutations was evaluated.

Results:

We found a statistical significant increase of mRNA levels in PTC tissue samples, compared with benign nodules and ATC. In particular, mRNA levels were maximal in differentiated thyroid cancer (PTC), progressively decreasing in more aggressive tumors, ATC having the lowest amount of praja2 mRNA. Accordingly, higher levels of praja2 protein were detected in lysates from PTC, compared with ATC. By immunohistochemistry, in PTC sections we observed a marked increase of cytoplasmic praja2 signal, which significantly decreased in less differentiated thyroid tumors, completely disappearing in ATC. Studies in cultured cells stably expressing RET/PTC1 oncogene or mutant BRAF revealed a direct correlation between praja2 mRNA levels and malignant phenotype of transformed cells. Similar results were obtained using thyroid cancer tissues carrying the same mutations.

Conclusions:

praja2 is markedly overexpressed in differentiated thyroid cancer, and its levels inversely correlate with the malignant phenotype of the tumor. Thus, praja2 is a novel cancer-related gene whose expression is linked to the histotype and mutational status of the thyroid tumor.
Thyroglobulin Autoantibodies in Patients with Papillary Thyroid Carcinoma: Comparison of Different Assays and Evaluation of Causes of Discrepancies
Authors: Latrofa Francesco , Ricci Debora , Montanelli Lucia , Rocchi Roberto , Piaggi Paolo , Sisti Eleonora , Grasso Lucia , Basolo Fulvio , Ugolini Clara , Pinchera Aldo , Vitti Paolo
Published: September 2012

Context:

Thyroglobulin autoantibodies (TgAb) have been proposed as a surrogate marker of thyroglobulin in the follow-up of differentiated thyroid carcinoma. Commercially available TgAb assays are often discordant. We investigated the causes of discrepancy.

Design:

TgAb were measured by three noncompetitive immunometric assays and three competitive RIA in 72 patients with papillary thyroid carcinoma and associated lymphocytic thyroiditis (PTC-T), 105 with papillary thyroid carcinoma and no lymphocytic thyroiditis (PTC), 160 with Hashimoto's thyroiditis, and in 150 normal subjects. The results of the six assays were correlated. TgAb epitope pattern, evaluated by inhibition of serum TgAb binding to thyroglobulin by TgAb-Fab regions A, B, C, and D, were compared in sera which were positive in all six assays (concordant sera) and positive in only one to five assays (discordant sera) were compared. TgAb International Reference Preparation (IRP) was measured in 2007 and 2009.

Results:

The correlations of the six assays ranged from −0.01 to 0.93 and were higher in PTC-T and Hashimoto's thyroiditis than in PTC and normal subjects. Two uncorrelated components, one including the three immunometric assays, the other the three RIA, explained 40 and 37% of the total variance of the results of the six assays. The levels of inhibition were higher in concordant sera than in discordant sera by TgAb-Fab region B (27.0%, 21.2–34.0 vs. 6.0%, and 2.7–12.7%) and region C (30.5%, 21.3–37.7 vs. 4.0%, and 1.0–6.5%); thus, the epitope pattern was more homogeneous in concordant sera than in discordant sera. TgAb IRP ranged from 157 to 1088 (expected 1000) IU/ml in 2009; results in 2007 were similar in all but two assays.

Conclusions:

TgAb assays are highly discordant. Discrepancy is lower when comparing assays with similar methodology. Results of TgAb from PTC-T are more concordant than those from PTC because their epitope pattern is more restricted. The internal standardization of TgAb is generally, but not completely, satisfactory.
Light and vision in the deep-sea benthos: I. Bioluminescence at 500–1000 m depth in the Bahamian Islands
Authors: Johnsen Sönke , Frank Tamara M. , Haddock Steven H. D. , Widder Edith A. , Messing Charles G.
Published: September 2012

Bioluminescence is common and well studied in mesopelagic species. However, the extent of bioluminescence in benthic sites of similar depths is far less studied, although the relatively large eyes of benthic fish, crustaceans and cephalopods at bathyal depths suggest the presence of significant biogenic light. Using the Johnson-Sea-Link submersible, we collected numerous species of cnidarians, echinoderms, crustaceans, cephalopods and sponges, as well as one annelid from three sites in the northern Bahamas (500–1000 m depth). Using mechanical and chemical stimulation, we tested the collected species for light emission, and photographed and measured the spectra of the emitted light. In addition, in situ intensified video and still photos were taken of different benthic habitats. Surprisingly, bioluminescence in benthic animals at these sites was far less common than in mesopelagic animals from similar depths, with less than 20% of the collected species emitting light. Bioluminescent taxa comprised two species of anemone (Actinaria), a new genus and species of flabellate Parazoanthidae (formerly Gerardia sp.) (Zoanthidea), three sea pens (Pennatulacea), three bamboo corals (Alcyonacea), the chrysogorgiid coral Chrysogorgia desbonni (Alcyonacea), the caridean shrimp Parapandalus sp. and Heterocarpus ensifer (Decapoda), two holothuroids (Elasipodida and Aspidochirota) and the ophiuroid Ophiochiton ternispinus (Ophiurida). Except for the ophiuroid and the two shrimp, which emitted blue light (peak wavelengths 470 and 455 nm), all the species produced greener light than that measured in most mesopelagic taxa, with the emissions of the pennatulaceans being strongly shifted towards longer wavelengths. In situ observations suggested that bioluminescence associated with these sites was due primarily to light emitted by bioluminescent planktonic species as they struck filter feeders that extended into the water column.
Light and vision in the deep-sea benthos: II. Vision in deep-sea crustaceans
Authors: Frank Tamara M. , Johnsen Sönke , Cronin Thomas W.
Published: September 2012

Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroretinography. Useable spectral sensitivity data were obtained from seven species, and in the dark-adapted eyes, the spectral sensitivity peaks were in the blue region of the visible spectrum, ranging from 470 to 497 nm. Under blue chromatic adaptation, a secondary sensitivity peak in the UV portion of the spectrum appeared for two species of anomuran crabs: Eumunida picta (λmax 363 nm) and Gastroptychus spinifer (λmax 383 nm). Wavelength-specific differences in response waveforms under blue chromatic adaptation in these two species suggest that two populations of photoreceptor cells are present. Temporal resolution was determined in all eight species using the maximum critical flicker frequency (CFFmax). The CFFmax for the isopod Booralana tricarinata of 4 Hz proved to be the lowest ever measured using this technique, and suggests that this species is not able to track even slow-moving prey. Both the putative dual visual pigment system in the crabs and the extremely slow eye of the isopod may be adaptations for seeing bioluminescence in the benthic environment.
Testosterone measurement by liquid chromatography tandem mass spectrometry: the importance of internal standard choice
Authors: Owen L J , Keevil B G
Published: September 2012

Background

Testosterone measurement by liquid chromatography tandem mass spectrometry (LC-MS/MS) is well accepted as the preferred technique for the analysis of testosterone. Variation is seen between assays and is likely to be due to method differences. One area of inconsistency among assays is the choice of internal standard. We investigated the effects of three internal standards.

Methods

Testosterone with two deuterium (D2), five deuterium (D5) and three carbon 13 enrichment (C13) were separately assessed. Samples were extracted using ether following the addition of 10 μL of internal standard. All aliquots were prepared in triplicate, one for each type of internal standard. After mixing, the ether was transferred to a 96-deep well block, and then evaporated to dryness. Extracts were reconstituted with 50% mobile phases and analysed using a Waters Acquity UPLC and Quattro Premier tandem mass spectrometer. This method had previously been shown to have excellent agreement with a reference method using the D2 internal standard and this was considered the target.

Results

Lower results were obtained when using D5 testosterone when compared with D2 testosterone. The C13 internal standard also gave lower results, but was closer to the D2 target than the D5 internal standard.

Conclusions

The choice of internal standard alone can have a significant affect on the results obtained by LC-MS/MS assays for testosterone using this chromatography. The effects of the combination of chromatography and internal standard choice should be investigated during method development.
Variations in Functional and Morphological Characteristics of Elite Polish Field Hockey Players in a Complete Macrocycle
Authors: Konarski Jan , Krzykała Magdalena , Podgórski Tomasz , Pawlak Maciej , Strzelczyk Ryszard , Malina Robert M.
Published: September 2012

The purpose was to evaluate a hypothesized model of change during a training and competition macrocycle in a sample of elite field hockey players. Subjects were 11 members of the Polish national team. Players were measured and tested four times through a complete macrocycle. Variables included body mass, %Fat (BIA), aerobic endurance, maximal running speed, speed-endurance and blood lactate concentrations after the endurance, speed and speed-endurance tests. Significant changes occurred in %Fat, aerobic endurance and blood lactate concentrations at different phases of the macrocycle. Mean changes for the total sample did not follow the hypothesized model for speed, aerobic endurance and speed-endurance between specific periods of the macrocycle. Variability among individual players was considerable and emphasized the importance of individualizing training protocols during a macrocycle. The results highlighted the need to consider specific functional capacities (speed, aerobic endurance, speed-endurance) of individual athletes in addition to technical and tactical skills.
Estimating Structural Models of Equilibrium and Cognitive Hierarchy Thinking in the Field: The Case of Withheld Movie Critic Reviews
Authors: Brown Alexander L. , Camerer Colin F. , Lovallo Dan
Published: September 2012

Film studios occasionally withhold movies from critics before their release. Because the unreviewed movies tend to be below average in quality, this practice provides a useful setting in which to test models of limited strategic thinking: Do moviegoers seem to realize that no review is a sign of low quality? A companion paper showed that in a set of all widely released movies in 2000–2009, cold opening produces a significant 20%–30% increase in domestic box office revenue, which is consistent with moviegoers overestimating quality of unreviewed movies (perhaps due to limited strategic thinking). This paper reviews those findings and provides two models to analyze this data: an equilibrium model and a behavioral cognitive hierarchy model that allows for differing levels of strategic thinking between moviegoers and movie studios. The behavioral model fits the data better, because moviegoer parameters are relatively close to those observed in experimental subjects. These results suggests that limited strategic thinking rather than equilibrium reasoning may be a better explanation for naïve moviegoer behavior.

This paper was accepted by Brad Barber, behavioral economics.
The Effect of CRM Outsourcing on Shareholder Value: A Contingency Perspective
Authors: Kalaignanam Kartik , Kushwaha Tarun , Steenkamp Jan-Benedict E. M. , Tuli Kapil R.
Published: September 2012

One central business activity that companies increasingly outsource is the information systems (IS) function. Previous research has shown that outsourcing of back-office IS generally has a positive effect on shareholder value of the outsourcing firm. Much less is known about the performance implications of outsourcing of another important IS function, namely, front-office customer relationship management (CRM) systems, where the vendor uses its own personnel and software to perform several CRM tasks. Previous, largely anecdotal evidence shows that the performance implications of outsourcing CRM range from very negative to very positive. To address this unsatisfactory state of knowledge, we provide and empirically test a contingency perspective on the performance implications of outsourcing CRM processes. We do so using the event-study methodology. The results are largely consistent with our contingency model. CRM outsourcing is more beneficial to firms that are high on information technology capabilities and low on marketing capabilities, and less beneficial when it concerns presales CRM. Similarly, although vendor economic distance has a positive influence on the outsourcing firm's shareholder value, vendor cultural distance has a negative influence. These effects are in turn significantly moderated by the type of CRM process outsourced.

This paper was accepted by Sandra Slaughter, information systems.
Dynamic Pricing of Substitutable Products in the Presence of Capacity Flexibility
Authors: Ceryan Oben , Sahin Ozge , Duenyas Izak
Published: September 2012

Firms that offer multiple products are often susceptible to periods of inventory mismatches where one product may face shortages while the other has excess inventories. In this paper, we study a joint implementation of price- and capacity-based substitution mechanisms to alleviate the level of such inventory disparities. We consider a firm producing substitutable products via a capacity portfolio consisting of both product-dedicated and flexible resources and characterize the structure of the optimal production and pricing decisions. We then explore how changes in various problem parameters affect the optimal policy structure. We show that the availability of a flexible resource helps maintain stable price differences across products over time even though the price of each product may fluctuate over time. This result has favorable ramifications from a marketing standpoint because it suggests that even when a firm applies a dynamic pricing strategy, it may still establish consistent price positioning among multiple products if it can employ a flexible replenishment resource. We provide numerical examples for the price stabilization effect and discuss extensions of our results to a more general multiple product setting.
Dynamic Pricing Under a General Parametric Choice Model
Authors: Broder Josef , Rusmevichientong Paat
Published: September 2012

We consider a stylized dynamic pricing model in which a monopolist prices a product to a sequence of T customers who independently make purchasing decisions based on the price offered according to a general parametric choice model. The parameters of the model are unknown to the seller, whose objective is to determine a pricing policy that minimizes the regret, which is the expected difference between the seller's revenue and the revenue of a clairvoyant seller who knows the values of the parameters in advance and always offers the revenue-maximizing price. We show that the regret of the optimal pricing policy in this model is [Formula: see text], by establishing an [Formula: see text] lower bound on the worst-case regret under an arbitrary policy, and presenting a pricing policy based on maximum-likelihood estimation whose regret is [Formula: see text] across all problem instances. Furthermore, we show that when the demand curves satisfy a “well-separated” condition, the T-period regret of the optimal policy is Θ(log T). Numerical experiments show that our policies perform well.
Strategies for a Centralized Single Product Multiclass M/G/1 Make-to-Stock Queue
Authors: Abouee-Mehrizi Hossein , Balcıoğlu Barış , Baron Opher
Published: September 2012

Make-to-stock queues are typically investigated in the M/M/1 settings. For centralized single-item systems with backlogs, the multilevel rationing (MR) policy is established as optimal and the strict priority (SP) policy is a practical compromise, balancing cost and ease of implementation. However, the optimal policy is unknown when service time is general, i.e., for M/G/1 queues. Dynamic programming, the tool commonly used to investigate the MR policy in make-to-stock queues, is less practical when service time is general. In this paper we focus on customer composition: the proportion of customers of each class to the total number of customers in the queue. We do so because the number of customers in M/G/1 queues is invariant for any nonidling and nonanticipating policy. To characterize customer composition, we consider a series of two-priority M/G/1 queues where the first service time in each busy period is different from standard service times, i.e., this first service time is exceptional. We characterize the required exceptional first service times and the exact solution of such queues. From our results, we derive the optimal cost and control for the MR and SP policies for M/G/1 make-to-stock queues.
Hazard Rate Scaling of the Abandonment Distribution for the GI/M/n + GI Queue in Heavy Traffic
Authors: Reed Josh , Tezcan Tolga
Published: September 2012

We obtain a heavy traffic limit for the GI/M/n + GI queue, which includes the entire patience time distribution. Our main approach is to scale the hazard rate function of the patience time distribution in such a way that our resulting diffusion approximation contains the entire hazard rate function. We then show through numerical studies that for various performance measures, our approximations tend to outperform those commonly used in practice. The robustness of our results is also demonstrated by applying them to solving constraint satisfaction problems arising in the context of telephone call centers.
Vancomycin Versus Linezolid in the Treatment of Methicillin-Resistant Staphylococcus aureus Nosocomial Pneumonia: Implications of the ZEPHyR Trial
Authors: Alaniz Cesar , Pogue Jason M
Published: September 2012

In 2003, a retrospective trial comparing linezolid versus vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) showed improved survival in the linezolid group. This ted to the ZEPHyR (Linezolid in the Treatment of Subjects with Nosocomial Pneumonia Proven to Be Due to Methicillin-Resistant Staphylococcus aureus) trial comparing linezolid versus vancomycin for MRSA pneumonia, which showed a benefit for linezolid with respect to clinical response but without a survival advantage. Limitations of the study included unbalanced treatment groups at baseline and number of patients excluded to reach the per-protocol group. Results of the ZEPHyR trial do not support routine use of linezolid for the treatment of MRSA pneumonia
Synthesis and Properties of Sn-Containing Magadiite
Authors: Supronowicz Wojciech , Roessner Frank , Schwieger Wilhelm , Meilikhov Mikhail , Esken Daniel
Published: September 2012

Hydrothermal syntheses of the magadiite, a layered silicate structure, were conducted in the presence of a heteroatom source (SnCl4.5H2O) with the intention of investigating its influence on the resulting material, as well as the possibility of isomorphous replacement of Si by Sn atoms in the abovementioned structure. For comparison, unmodified magadiite, Al-containing magadiite, and impregnated magadiite were synthesized. The magadiite structure was identified for samples with Sn/Si ratios up to 0.015. Synthetic methods applied to Sn-modified materials were found to be unsuitable for the introduction of Al. The characterization methods used were X-ray diffraction, temperature-programmed reduction, and 29Si magic angle spinning nuclear magnetic resonance and these revealed the substitution of Si by Sn in the silica layers. No additional acid centers on the surfaces of the modified samples were detected, suggesting the presence of the desired four-coordinate Sn in the silica layers.
Mg-Bentonite in the Parnaíba Paleozoic Basin, Northern Brazil
Authors: Aranha da Paz Simone Patrícia , Angélica Rômulo Simões , de Freitas Neves Roberto
Published: September 2012

Bentonite deposits are rare in Brazil and most of their production comes from a single region. A new bentonite occurrence, the Formosa bentonite from northern Brazil, is described here. The occurrence is associated with altered Mesozoic volcanic rocks of the Parnaíba Sedimentary Basin, one of the largest continental flood basalt (CFB) provinces on Earth. The purpose of the present study was to evaluate the physical and chemical properties of a new smectite-bearing deposit in Brazil. Analysis has shown that the major mineral present in the Formosa bentonite is a dioctahedral smectite along with minor amounts of hematite, K-feldspar, and kaolinite. Quartz is absent. A Li+-saturation test (Hofmann-Klemen treatment) revealed a montmorillonite smectite; large interlayer-Mg2+ contents revealed by N2 adsorption/desorption and cation exchange capacity results suggested a Mg-bentonite. This characterization helped to explore the structure-functionality (reactivity) relationship and to develop index tests for industrial applications and the research of new materials.

Use of this material as a desiccant-grade bentonite is envisaged (desiccant-grade bentonites contain Mg2+ and/or Ca2+ as the dominant exchangeable cations), or it could be activated with Na+ for use in many industrial applications (e.g. as a drilling fluid or for pelletizing iron ore). The large areal occurrence of the flood basalts suggests the possibility of very large deposits of these bentonites, a promising new exploration target for this class of industrial minerals in northern Brazil.
Effects of Mg, Ca, and Fe(II) Doping on the Kaolinite (001) Surface with H2O Adsorption
Authors: He Man-Chao , Zhao Jian
Published: September 2012

Kaolinite is often a cause of deformation in soft-rock tunnel engineering, leading to safety problems. The mechanism of the deformation is closely related to the interaction between kaolinite and water molecules. Because kaolinite has multiple defects, the effects of Mg, Ca, and Fe(II) doping on the atomic structure of the kaolinite (001) surface, and the subsequent adsorption and penetration of H2O into the interlayer, were studied systematically using density-functional theory. The results showed that for the Mg-, Ca-, and Fe(II)-doped kaolinites (001), the surface relaxation around the doping layer changed from contraction to expansion, due to the redistribution of electrons. The adsorption energies of the H2O monomer on Mg-, Ca-, and Fe(II)-doped kaolinites (001) were less than on undoped kaolinite (001). The results further revealed that the H2O molecule can also adsorb on the hollow site on the second-layer O surface of the Mg-, Ca-, and Fe(II)-doped kaolinites (001). For the undoped kaolinite, however, the H2O molecule adsorbs on the surface only. The energetic barriers for penetration of H2O from the adsorption site on the surface to the adsorption site on the O surface of Mg-, Ca-, and Fe(II)-doped kaolinites were also calculated: 1.18 eV, 1.07 eV, and 1.41 eV, respectively. The results imply that the influences of Mg, Ca, and Fe(II) doping on kaolinite allow the adsorbed water molecules to penetrate from the on-surface adsorption site to the O-surface site.