bluuebunny/crossref_metadata_2025 huggingface dataset:
An Equilibrator System to Measure Dissolved Oxygen and Its Isotopes
Authors: Rafelski Lauren Elmegreen , Paplawsky Bill , Keeling Ralph F.
Published: October 2012

An equilibrator is presented that is designed to have a sufficient equilibration time even for insoluble gases, and to minimize artifacts associated with not equilibrating to the total gas tension. A gas tension device was used to balance the pressure inside the equilibrator with the total gas tension. The equilibrator has an e-folding time of 7.36 ± 0.74 min for oxygen and oxygen isotopes, allowing changes on hourly time scales to be easily resolved. The equilibrator delivers “equilibrated” air at a flow rate of 3 mL min−1 to an isotope ratio mass spectrometer. The high gas sampling flow rate would allow the equilibrator to be interfaced with many potential devices, but further development may be required for use at sea. This system was tested at the Scripps Institution of Oceanography pier, in La Jolla, California. A mathematical model validated with performance tests was used to assess the sensitivity of the equilibrated air composition to headspace pressure and makeup gas composition. Parameters in this model can be quantified to establish corrections under different operating conditions. For typical observed values, under the operating conditions presented here, the uncertainty in the measurement due to the equilibrator system is 2.2 per mil for δ(O2/N2), 1.5 per mil for δ(O2/Ar), 0.059 per mil for δ18O, and 0.0030 per mil for Δ17O.
The Meaning of Development:Reflections of an Octogenarian Teacher of Economics
Authors: Oommen M.A.
Published: October 2012

In any science the meaning given to concepts and the way they are used profoundly influence the formulation of problems and the manner of seeking solutions. This article based on the experiences of an economics teacher of long-standing innings, traces the distortions introduced into the discipline of economics, legitimised by a long tradition of economists who tried to make it a science like physics with universally valid postulates and principles. In this process the discipline has strayed away from social reality which quintessentially is rooted in social relationships. No wonder development economics has no crucial contribution or critical role to play in conquering under development, inequality and unfreedoms that have undermined the tremendous flourishings which the general mass of humanity could have accomplished over the years. It is in this setting that the article underscores the significance of development as freedom, equality, care and social inclusion.
The Evolving Understanding of Recovery
Authors: Watson Dennis P.
Published: October 2012

The meaning of recovery from serious mental illness (SMI) has evolved over time. Whereas it was not even considered to be a primary goal of treatment 30 years ago, it is the main focus of mental health policy today. These changes are partially the result of sociological research conducted during the age of institutional treatment and the early stages of community-based care. Despite these early influences, the sociology of mental health has largely overlooked the explicit study of recovery. This is because sociologists began shifting their focus from the study of SMI to the study of less severe mental health problems beginning in 1970s. In this article, I (a) discuss the evolving history of mental health recovery; (b) discuss how recovery is defined today in policy, practice, and research; and (c) present an argument for why sociological perspectives and methods can help shed light on the tensions between the definitions while assisting to develop better understandings of the recovery process. In this argument, I place particular attention on qualitative social psychological perspectives and methods because they hold the most potential for addressing some of the central concerns in the area of recovery research.
Parallel changes in serotonin levels in brain and blood following acute administration of MDMA
Authors: Collins Cheryl M , Kloek Joris , Elliott J Martin
Published: October 2012

Recent studies have demonstrated a similar acute effect of 3,4- methylenedioxymethamphetamine (MDMA) in blood platelets and brain tissue via action on the serotonin transporter. To investigate the validity of blood serotonin as a peripheral marker for central serotonin in this regard, we administered MDMA (20 mg/kg i.p.) to rats and observed a parallel decrease in serotonin levels in the frontal cortex and blood at 2 h (63% and 46% respectively) with some recovery evident at 8 h (42% and 38%) and more so at 18 h (19% and 24% below control levels). Administration of a tryptophan supplement (82.5 mg/kg p.o.) to naïve rats produced parallel increases in serotonin levels 2 h later in the frontal cortex (39%) and blood (26%). Following MDMA administration, the same dose of tryptophan caused a smaller (26%) rise in brain serotonin whereas in blood it had no effect. We conclude that blood serotonin is a useful marker for brain serotonin levels in the rat following acute administration of MDMA and this finding highlights the possible use of platelet serotonin as a marker for brain serotonin in human studies involving MDMA.
Becoming Teen Fathers
Authors: Weber Jennifer Beggs
Published: October 2012

Drawing on in-depth interviews, I analyze how teen fathers talk about the responsibility for having a baby at a young age. In addition to negotiating the stigma often associated with teen pregnancy, teen fathers also confront stereotypes that label them as selfish and uncaring. In telling their stories of “what happened,” they utilize three gendered discourses to deny responsibility for the pregnancy: the feminization of birth control, a discourse of uncontrollable male sexual desire, and love. Their narratives also reveal the ways in which gendered norms can solve some problems while creating others. Aligning themselves with certain notions of masculinity can serve as a resource for denying responsibility for the pregnancy while also signifying their manhood, but these same discourses are also constraining in that they reinforce stereotypes of teen fathers as selfish, even predatory. While these approaches may allow teen fathers to claim masculine identities, they also stigmatize them as the wrong kind of men. In short, teen fathers are not only negotiating the potential stigma of teen pregnancy, they are also negotiating their identities as men.
Productive thyroid follicular carcinoma in a wild barred owl (Strix varia)
Authors: Brandão João , Manickam Bala , Blas-Machado Uriel , Cohen Eli , Mejia-Fava Johanna , Divers Stephen , Mayer Jörg
Published: October 2012

An adult male barred owl ( Strix varia) was found unable to fly on a pasture during the day. On presentation, several lacerations were noted on the left wing. The animal was anesthetized for radiographic examination, which revealed mild swelling and irregularity of the soft tissues of the left wing. Over the plane of the syrinx and great vessels, ill-defined soft tissue opacity was present. The anesthetic recovery was unsuccessful, and the patient died. On gross necropsy, a 1 cm in diameter, round, soft, red-tan nodule, with scattered light tan to white foci was noticed between the right subclavian artery and the syrinx. The histopathology of this structure was characteristic of a thyroid follicular carcinoma. Neoplastic cells were immunoreactive to thyroglobulin and pancytokeratin proteins. A blood sample, taken antemortem, was analyzed for total and free thyroxine. Due to the lack of reference intervals for the current species, 4 blood samples from other barred owls were taken, 2 of which were clinically normal and 2 with an unhealthy status. The thyroid values were higher than the controls (total thyroxine by radioimmunoassay [µg/dl] 1.1 vs. <0.2, <0.2, 0.6, <0.2; free thyroxine by equilibrium dialysis [ng/dl] >10 vs. <0.3, <0.3, 2.1, <0.3). Although the other 4 birds are not intended to serve as a reference interval because of the low number and unhealthy status, findings are indicative of a productive thyroid follicular carcinoma.
Safety Assessment of Alkyl PEG Ethers as Used in Cosmetics
Authors: Fiume Monice M. , Heldreth Bart , Bergfeld Wilma F. , Belsito Donald V. , Hill Ronald A. , Klaassen Curtis D. , Liebler Daniel , Marks James G. , Shank Ronald C. , Slaga Thomas J. , Snyder Paul W. , Andersen F. Alan
Published: October 2012

The CIR Expert Panel assessed the safety of Alkyl PEG Ethers as used in cosmetics. These ingredients primarily function in cosmetics as surfactants, and some have additional functions as skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Panel reviewed available relevant animal and clinical data, as well as information from previous CIR reports; when data were not available for individual ingredients, the Panel extrapolated from the existing data to support safety. The Panel concluded that the Alkyl PEG ethers are safe as used when formulated to be nonirritating, and the same applies to future alkyl PEG ether cosmetic ingredients that vary from those ingredients recited herein only by the number of ethylene glycol repeat units.
Safety Assessment of Stearyl Heptanoate and Related Stearyl Alkanoates as Used in Cosmetics
Authors: Fiume Monice M. , Bergfeld Wilma F. , Belsito Donald V. , Hill Ronald A. , Klaassen Curtis D. , Liebler Daniel , Marks James G. , Shank Ronald C. , Slaga Thomas J. , Snyder Paul W. , Andersen F. Alan
Published: October 2012

Stearyl heptanoate is an ester of stearyl alcohol and heptanoic acid that functions in cosmetics as a skin conditioning agent and is in the general class of chemicals called stearyl alkanoates. Stearyl caprylate, stearyl palmitate, stearyl stearate, stearyl behenate, and stearyl olivate are stearyl alkanoates with similar chemical structures, toxicokinetics, and functions in cosmetics. These water-insoluble stearyl alkanoates, when metabolized, yield stearyl alcohol and a corresponding fatty acid. The available information supports the safety of all of the related stearyl alkanoates. The Expert Panel concluded that stearyl heptanoate, stearyl caprylate, stearyl palmitate, stearyl stearate, stearyl behenate, and stearyl olivate are safe in the present practices of use and concentration.
Retailing retro: Class, cultural capital and the material practices of the (re)valuation of style
Authors: Baker Sarah Elsie
Published: October 2012

When retro retailers buy and sell goods they are appropriating and recontextualising objects and styles both symbolically and materially. Through knowledge and practices they change the value of items from everyday and old-fashioned to unique and desirable. In this process of value creation, retailers mediate between production and consumption and translate and evaluate other cultures. As such, their role fits well with past theorisations of cultural intermediaries. Using ethnographic research conducted with eight retailers of retro furniture and 12 retro enthusiasts between 2006 and 2010 in the UK, this article reflects on the usefulness of the concept of the cultural intermediary. Through a discussion of the practices and identities of retro retailers it is argued that studies of cultural intermediaries can be enriched by examining the relationships that intermediaries have with the producers and consumers to whom they mediate, as well as improved by exploring the spaces and materialities of mediation.
Placing Nature(s) on Safari
Authors: Hays Cassie M
Published: October 2012

Unlike destination-based tourism, safari, by definition, implies perpetual mobility. This historically layered process of continuous movement across and through specific landscapes defines the safari as a unique travel experience. Taking travel as performative and processual, this study investigates the role of various technologies of travel in the emplacement, erasure, traversal, and categorization of place on safari; the creation of a topology of safari places and natures by and for visitors; and local Maasai challenges to much of this place- and nature-making. This results in an “imbrication” of place, of the local and the official, of the deep and the superficial, such that the placing of safari spaces comes to be seen as a deeply dialectical, multisensory process involving multiple actors.
Eligibility criteria in randomized phase II and III adjuvant and neoadjuvant breast cancer trials: Not a significant barrier to enrollment
Authors: Filion Myriam , Forget Geneviève , Brochu Olyvia , Provencher Louise , Desbiens Christine , Doyle Catherine , Poirier Brigitte , DuRocher Martin , Camden Stéphanie , Lemieux Julie
Published: October 2012

Background

Clinical trial recruitment can be impeded by eligibility criteria being too numerous or too restrictive.

Purpose

This study’s principal objective was to determine whether a specific category of eligibility criteria could be identified as a major barrier to patient enrollment.

Methods

Nine phase II or III clinical trials, opened between June 2004 and July 2008, were selected. A retrospective cohort of women diagnosed with invasive, nonmetastatic breast cancer and potentially eligible for these clinical trials was used. All eligibility criteria were sorted into the following categories: definition of disease, precision, safety, ethical and legal, or administrative. A total of 985 patient-trials were evaluated, defined as the experimental unit since one patient could be eligible to more than one trial. Proportions of cases with ‘not met’ eligibility criteria were assessed for each category in each trial.

Results

Two clinical trials had a ‘not met’ subcategory criterion of over 20%. ‘Pathology’ and ‘consent’ subcategory criteria were ‘not met’ in 24.2% and 92.7% of cases for the NEOCAN and NCIC CTG MA.27 trials, respectively. NCIC CTG MA.27 had the highest proportion of ‘not met’ subcategory due to an inclusion criterion requiring participation to two companion studies. National Surgical Adjuvant Breast and Bowel Project (NSABP) B-38 had a proportion of 18.8% of cases ‘not meeting’ the receptor status subcategory criterion. All other subcategories of eligibility criteria assessed were ‘not met’ by less than 15% of patients. Overall, few subcategories had over 10% of ineligible patients.

Limitations

Many eligibility criteria were considered ‘nonevaluable’ because the information evaluated would have required additional procedures not performed as part of the general practice.

Conclusion

The subjects from the study population are not precluded from entry in a trial because of stringent eligibility criteria. Eligibility criteria should reflect as much as possible the whole population to whom the treatment will be offered, with the exception of drugs targeting a specific receptor or pathway where only a subpopulation is hypothesized to benefit from the therapy. In the breast cancer clinical trials evaluated for the present study, no criterion precluding recruitment was shared by many or all trials and no specific eligibility criterion was consistently the reason for patients’ ineligibility.
Macrolide resistance determinants among Streptococcus pneumoniae isolates from carriers in Central Greece
Authors: Grivea Ioanna N , Sourla Alexia , Ntokou Eleni , Chryssanthopoulou Denise C , Tsantouli Alexandra G , Syrogiannopoulos George A
Published: October 2012

Background

We sought to characterize the temporal trends in nasopharyngeal carriage of macrolide-resistant pneumococci during a period with increased heptavalent pneumococcal conjugate vaccine (PCV7) coverage in Central Greece.

Methods

Streptococcus pneumoniae isolates were recovered from 2649 nasopharyngeal samples obtained from day-care center attendees in Central Greece during 2005–2009. A phenotypic and genotypic analysis of the isolates was performed, including the identification of macrolide resistance genes mef(A), subclasses mef(A) and mef(E), as well as erm(B).

Results

Of the 1105 typeable S. pneumoniae isolates, 265 (24%) were macrolide-resistant; 22% in 2005, 33.3% in 2006, 23.7% in 2007, and 20.5% in 2009 (P=0.398). Among these macrolide-resistant pneumococci, 28.5% possessed erm(B), 24.3% erm(B)+mef(E), 41.8% mef(E), and 5.3% mef(A). A mef gene as the sole resistance determinant was carried by 31% of macrolide-resistant isolates belonging to PCV7 serotypes and 75.8% of the non-PCV7 serotypes. Across the 4 annual surveillances, pneumococci carrying mef(A) gradually disappeared, whereas serotype 19F isolates carrying both erm(B) and mef(E) persisted without significant yearly fluctuations. Among isolates belonging to non-PCV7 serotypes, macrolide-resistance was observed in those of serotypes 6A, 19A, 10A, 15A, 15B/C, 35F, 35A, and 24F. In 2009, ie 5 years after the introduction of PCV7 in our country, 59% of macrolide-resistant pneumococci belonged to non-PCV7 serotypes.

Conclusions

Across the study period, the annual frequency of macrolide-resistant isolates did not change significantly, but in 2009 a marked shift to non-PCV7 serotypes occurred. Overall, more than half of the macrolide-resistant isolates possessed erm(B) either alone or in combination with mef(E). erm(B) dominated among isolates belonging to PCV7 serotypes, but not among those of non-PCV7 serotypes.
Novel synergistic antitumor effects of rapamycin with bortezomib on hepatocellular carcinoma cells and orthotopic tumor model
Authors: Wang Cun , Gao Dongmei , Guo Kun , Kang Xiaonan , Jiang Kai , Sun Chun , Li Yan , Sun Lu , Shu Hong , Jin Guangzhi , Sun Haiyan , Wu Weizhong , Liu Yinkun
Published: October 2012

Background

Despite recent advances in the treatment of hepatocellular carcinoma (HCC), the chemotherapy efficacy against HCC is still unsatisfactory. The mammalian target of rapamycin (mTOR) has been emerged as an important cancer therapeutic target. However, HCC cells often resistant to rapamycin because of the paradoxical activation of Akt by rapamycin. In this study, we investigated whether bortezomib could enhance the antitumor effects of rapamycin.

Methods

The effects of rapamycin and bortezomib on HCC proliferation, apoptosis, migration, and invasiveness in vitro were assessed by CCK-8 analysis, flow cytometry, Hoechst 33342 staining and transwell assays, respectively. Total and phosphorylated protein levels of Akt were detected by Western blotting. The effects of rapamycin and/or bortezomib on the mRNA expression levels of p53, p27, p21 and Bcl-2 family in HCCLM3 cells were evaluated by RT-PCR. The roles of rapamycin and bortezomib on HCC growth and metastasis in xenograft models were evaluated by tumor volumes and fluorescent signals. The effects of rapamycin and bortezomib on cell proliferation and apoptosis in vivo were test by PCNA and TUNEL staining.

Results

Bortezomib synergized with rapamycin to reduce cell growth, induce apoptosis, and inhibit cell mobility in vitro. Further mechanistic studies showed that bortezomib inhibited rapamycin-induced phosphorylated Akt, which in turn enhanced apoptosis of HCC cell lines. The alteration of the mRNA expression of cell cycle inhibitors p53, p27, p21 and apoptosis associated genes Bcl-2, Bax were also involved in the synergistic antitumor effects of rapamycin and bortezomib. P53 inhibitor PFT-α significantly attenuate the effect of rapamycin and bortezomib on cell apoptosis, which indicated that the pro-apoptotic effect of rapamycin and bortezomib may be p53-dependent. Treatment of HCCLM3-R bearing nude mice with rapamycin and bortezomib significantly enhanced tumor growth inhibition (72.4%), comparing with either rapamycin- (54.7%) or bortezomib-treated mice (22.4%). In addition, the lung metastasis was significantly suppressed in mice received the combination treatment (16.6%). The combination treatment of rapamycin and bortezomib significantly inhibited tumor cell proliferation and tumor angiogenesis in vivo.

Conclusion

The combination of rapamycin with bortezomib could be a novel and promising therapeutic approach to the treatment of HCC.
Protocol for a randomized controlled trial evaluating the effect of physical activity on delaying the progression of white matter changes on MRI in older adults with memory complaints and mild cognitive impairment: The AIBL Active trial
Authors: Cyarto Elizabeth V , Lautenschlager Nicola T , Desmond Patricia M , Ames David , Szoeke Cassandra , Salvado Olivier , Sharman Matthew J , Ellis Kathryn A , Phal Pramit M , Masters Colin L , Rowe Christopher C , Martins Ralph N , Cox Kay L
Published: October 2012

Background

Older adults free of dementia but with subjective memory complaints (SMC) or mild cognitive impairment (MCI) are considered at increased risk of cognitive decline. Vascular risk factors (VRF), including hypertension, heart disease, smoking, hypercholesterolemia and lack of physical activity (PA) have been identified as modifiable risk factors contributing to cognitive decline, and white matter hyperintensities (WMH) are associated with VRF, SMC and cognitive impairment. Findings from a growing number of clinical trials with older adults are providing strong evidence for the benefits of physical activity for maintaining cognitive function, but few studies are investigating these benefits in high-risk populations. The aim of AIBL Active is to determine whether a 24-month physical activity program can delay the progression of white matter changes on magnetic resonance imaging (MRI).

Methods/design

This single-blind randomized controlled trial (RCT) is offered to 156 participants, aged 60 and older, in the Melbourne arm of the Australian Imaging Biomarkers and Lifestyle Flagship Study of Aging (AIBL). Participants must have SMC with or without MCI and at least one VRF. The PA intervention is a modification of the intervention previously trialed in older adults with SMC and MCI (Fitness for the Ageing Brain Study). It comprises 24 months of moderate, home-based PA (150 minutes per week) and a behavioral intervention package. The primary outcome measure will be change in WMH after 24 months on MRI. Cognition, quality of life, functional fitness, level of physical activity, plasma biomarkers for cerebrovascular disease and amyloid positron emission tomography (PET) imaging comprise secondary measures.

Discussion

Currently, there is no effective pharmacological treatment available to delay cognitive decline and dementia in older adults at risk. Should our findings show that physical activity can slow down the progression of WMH, this RCT would provide an important proof of concept. Since imbedded in AIBL this RCT will also be able to investigate the interaction between vascular and Alzheimer's disease pathologies.

Trial Registration

Australia New Zealand Clinical Trials Registry ACTRN12611000612910
Understanding the drive to escort: a cross-sectional analysis examining parental attitudes towards children’s school travel and independent mobility
Authors: Mammen George , Faulkner Guy , Buliung Ron , Lay Jennifer
Published: October 2012

Background

The declining prevalence of Active School Transportation (AST) has been accompanied by a decrease in independent mobility internationally. The objective of this study was to compare family demographics and AST related perceptions of parents who let their children walk unescorted to/from school to those parents who escort (walk and drive) their children to/from school. By comparing these groups, insight was gained into how we may encourage greater AST and independent mobility in youth living in the Greater Toronto and Hamilton Area, Canada.

Methods

This study involved a cross-sectional design, using data from a self-reported questionnaire (n =1,016) that examined parental perceptions and attitudes regarding AST. A multinomial logistic regression analysis was used to explore the differences between households where children travelled independently to school or were escorted.

Results

Findings revealed that unescorted children were: significantly older, the families spoke predominantly English at home, more likely to live within one kilometer from school, and their parents agreed to a greater extent that they chose to reside in the current neighborhood in order for their child to walk to/from school. The parents of the escorted children worried significantly more about strangers and bullies approaching their child as well as the traffic volume around school.

Conclusions

From both a policy and research perspective, this study highlights the value of distinguishing between mode (i.e., walking or driving) and travel independence. For policy, our findings highlight the need for planning decisions about the siting of elementary schools to include considerations of the impact of catchment size on how children get to/from school. Given the importance of age, distance, and safety issues as significant correlates of independent mobility, research and practice should focus on the development and sustainability of non-infrastructure programs that alleviate parental safety concerns.
Reduction of n-3 PUFAs, specifically DHA and EPA, and enhancement of peroxisomal beta-oxidation in type 2 diabetic rat heart
Authors: Hou Lianguo , Lian Kaoqi , Yao Min , Shi Yun , Lu Xin , Fang Lijia , He Tianbo , Jiang Lingling
Published: October 2012

Background

There is overwhelming evidence that dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs), mainly EPA (C20:5n-3) and DHA (C22:6n-3), has cardiovascular protective effects on patients with type 2 diabetes mellitus (T2DM) but not on healthy people. Because the T2DM heart increases fatty acid oxidation (FAO) to compensate for the diminished utilization of glucose, we hypothesize that T2DM hearts consume more n-3 PUFAs and, therefore, need more n-3 PUFAs. In the present study, we investigated the changes in cardiac n-3 PUFAs and peroxisomal beta-oxidation, which are responsible for the degradation of PUFAs in a high-fat diet (HFD) and low-dose streptozotocin- (STZ) induced type 2 diabetic rat model.

Methods and results

The capillary gas chromatography results showed that all the n-3 (or omega-3) PUFAs, especially DHA (~50%) and EPA (~100%), were significantly decreased, and the n-6/n-3 ratio (~115%) was significantly increased in the hearts of diabetic rats. The activity of peroxisomal beta-oxidation, which is crucial to very-long-chain and unsaturated FA metabolism (including DHA), was significantly elevated in DM hearts. Additionally, the real-time PCR results showed that the mRNA expression of most peroxisomal beta-oxidation key enzymes were up-regulated in T2DM rat hearts, which might contribute to the reduction of n-3 (or omega-3) PUFAs.

Conclusion

In conclusion, our results indicate that T2DM hearts consume more n-3 PUFAs, especially DHA and EPA, due to exaggerated peroxisomal beta-oxidation.
Conversion of rod-shaped gold nanoparticles to spherical forms and their effect on biodistribution in tumor-bearing mice
Authors: Akiyama Yasuyuki , Mori Takeshi , Katayama Yoshiki , Niidome Takuro
Published: October 2012

Gold nanorods that have an absorption band in the near-infrared region and a photothermal effect have been used as nanodevices for near-infrared imaging and thermal therapy. Choice of the optimal shape of gold nanorods which relates optical properties and in vivo biodistribution is important for their applications. In the present study, to investigate the relationship between the shape of gold nanorods and their biodistribution after intravenous injection, we first prepared two types of gold nanorods that had distinct aspect ratios but had the same volume, zeta potential, and PEG density on the gold surface. Biodistributions of the two types of gold nanorods after intravenous injection into tumor-bearing mice were then compared. Although a slight difference in accumulation in the spleen was observed, no significant difference was observed in the liver, lung, kidney, and tumors. These results suggest that biodistribution of the gold nanorods in the aspect ratio range of 1.7 to 5.0, diameter of 10 to 50 nm, and volume of approximately 4 × 103 nm3 was dependent mainly on surface characteristics, PEG density, and zeta potential.
Coupled fixed point theorems on partially ordered G-metric spaces
Authors: Karapınar Erdal , Kumam Poom , Erhan Inci M
Published: October 2012

The purpose of this paper is to extend some recent coupled fixed point theorems in the context of partially ordered G-metric spaces in a virtually different and more natural way.

MSC:46N40, 47H10, 54H25, 46T99.
Characterization of sequence elements from Malvastrum yellow vein betasatellite regulating promoter activity and DNA replication
Authors: Zhang Jie , Zhang Xinyue , Wang Yaqin , Hou Huwei , Qian Yajuan
Published: October 2012

Background

Many monopartite begomoviruses are associated with betasatellites, but only several promoters from which were isolated and studied. In this study, theβC1promoter from Malvastrum yellow vein betasatellite (MYVB) was characterized and important sequence elements were identified to modulate promoter activity and replication of MYVB.

Results

A 991 nucleotide (nt) fragment upstream of the translation start site of theβC1open reading frame of MYVB and a series of deletions within this fragment were constructed and fused to the β-glucuronidase (GUS) and green fluorescent protein (GFP) reporter genes, respectively.Agrobacterium-mediated transient expression assays showed that the 991 nt fragment was functional and that a 28 nt region (between −390 nt and −418 nt), which includes a 5′UTR Py-rich stretch motif, was important for promoter activity. Replication assays usingNicotiana benthamianaleaf discs and whole plants showed that deletion of the 5′UTR Py-rich stretch impaired viral satellite replication in the presence of the helper virus. Transgenic assays demonstrated that the 991 nt fragment conferred a constitutive expression pattern in transgenic tobacco plants and that a 214 nt fragment at the 3'-end of this sequence was sufficient to drive this expression pattern.

Conclusion

Our results showed that theβC1promoter of MYVB displayed a constitutive expression pattern and a 5′UTR Py-rich stretch motif regulated bothβC1promoter activity and MYVB replication.
Boosting the free fatty acid synthesis of Escherichia coli by expression of a cytosolic Acinetobacter baylyi thioesterase
Authors: Zheng Yanning , Li Lingling , Liu Qiang , Qin Wen , Yang Jianming , Cao Yujin , Jiang Xinglin , Zhao Guang , Xian Mo
Published: October 2012

Background

Thioesterases remove the fatty acyl moiety from the fatty acyl-acyl carrier proteins (ACPs), releasing them as free fatty acids (FFAs), which can be further used to produce a variety of fatty acid-based biofuels, such as biodiesel, fatty alcohols and alkanes. Thioesterases play a key role in the regulation of the fatty acid synthesis in Escherichia coli. Therefore, exploring more promising thioesterases will contribute to the development of industrial microbial lipids production.

Results

We cloned and expressed a cytosolic Acinetobacter baylyi thioesterase (‘AcTesA) in E. coli by deleting its leader sequence. Protein sequence alignment, structure modeling and site-directed mutagenesis demonstrated that Ser10, Gly48, Asn77, Asp158 and His161 residues composed the active centre of ‘AcTesA. The engineered strain that overexpressed ‘AcTesA achieved a FFAs titer of up to 501.2 mg/L in shake flask, in contrast to only 20.5 mg/L obtained in wild-type E. coli, demonstrating that the expression of ‘AcTesA indeed boosted the synthesis of FFAs. The ‘AcTesA exhibited a substrate preference towards the C8-C16 acyl groups, with C14:0, C16:1, C12:0 and C8:0 FFAs being the top four components. Optimization of expression level of ‘AcTesA made the FFAs production increase to 551.3 mg/L. The FFAs production further increased to 716.1 mg/L by optimization of the culture medium. Fed-batch fermentation was also carried out to evaluate the FFAs production in a scaleable process. Finally, 3.6 g/L FFAs were accumulated within 48 h, and a maximal FFAs yield of 6.1% was achieved in 12–16 h post induction.

Conclusions

For the first time, an A. baylyi thioesterase was cloned and solubly expressed in the cytosol of E. coli. This leaderless thioesterase (‘AcTesA) was found to be capable of enhancing the FFAs production of E. coli. Without detailed optimization of the strain and fermentation, the finally achieved 3.6 g/L FFAs is encouraging. In addition, ‘AcTesA exhibited different substrate specificity from other thioesterases previously reported, and can be used to supply the fatty acid-based biofuels with high quality of FFAs. Altogether, this study provides a promising thioesterase for FFAs production, and is of great importance in enriching the library of useful thioesterases.
Shifts in human skin and nares microbiota of healthy children and adults
Authors: Oh Julia , Conlan Sean , Polley Eric C , Segre Julia A , Kong Heidi H
Published: October 2012

Background

Characterization of the topographical and temporal diversity of the microbial collective (microbiome) hosted by healthy human skin established a reference for studying disease-causing microbiomes. Physiologic changes occur in the skin as humans mature from infancy to adulthood. Thus, characterizations of adult microbiomes might have limitations when considering pediatric disorders such as atopic dermatitis (AD) or issues such as sites of microbial carriage. The objective of this study was to determine if microbial communities at several body sites in children differed significantly from adults.

Methods

Using 16S-rRNA gene sequencing technology, we characterized and compared the bacterial communities of four body sites in relation to Tanner stage of human development. Body sites sampled included skin sites characteristically involved in AD (antecubital/popliteal fossae), a control skin site (volar forearm), and the nares. Twenty-eight healthy individuals aged from 2 to 40 years were evaluated at the outpatient dermatology clinic in the National Institutes of Health's Clinical Center. Exclusion criteria included the use of systemic antibiotics within 6 months, current/prior chronic skin disorders, asthma, allergic rhinitis, or other chronic medical conditions.

Results

Bacterial communities in the nares of children (Tanner developmental stage 1) differed strikingly from adults (Tanner developmental stage 5). Firmicutes (Streptococcaceae), Bacteroidetes, and Proteobacteria (β, γ) were overrepresented in Tanner 1 compared to Tanner 5 individuals, where Corynebacteriaceae and Propionibacteriaceae predominated. While bacterial communities were significantly different between the two groups in all sites, the most marked microbial shifts were observed in the nares, a site that can harbor pathogenic species, including Staphylococcusaureus and Streptococcus pneumonia.

Conclusions

Significant shifts in the microbiota associated with progressive sexual maturation as measured by Tanner staging suggest that puberty-dependent shifts in the skin and nares microbiomes may have significant implications regarding prevention and treatment of pediatric disorders involving microbial pathogens and colonization.
Frustrated Demand for Sterilization Among Low‐Income Latinas in El Paso, Texas
Authors: Potter Joseph E. , White Kari , Hopkins Kristine , McKinnon Sarah , Shedlin Michele G. , Amastae Jon , Grossman Daniel
Published: October 2012

CONTEXT

Sterilization is the most commonly used contraceptive in the United States, yet access to this method is limited for some.

METHODS

A 2006–2008 prospective study of low‐income pill users in El Paso, Texas, assessed unmet demand for sterilization among 801 women with at least one child. Multivariable logistic regression analysis identified characteristics associated with wanting sterilization. In 2010, at an 18‐month follow‐up, women who had wanted sterilization were recontacted; 120 semistructured and seven in‐depth interviews were conducted to assess motivations for undergoing the procedure and the barriers faced in trying to obtain it.

RESULTS

At baseline, 56% of women wanted no more children; at nine months, 65% wanted no more children, and of these, 72% wanted sterilization. Only five of the women interviewed at 18 months had undergone sterilization; two said their partners had obtained a vasectomy. Women who had not undergone sterilization were still strongly motivated to do so, mainly because they wanted no more children and were concerned about long‐term pill use. Among women's reasons for not having undergone sterilization after their last pregnancy were not having signed the Medicaid consent form in time and having been told that they were too young or there was no funding for the procedure.

CONCLUSIONS

Because access to a full range of contraceptive methods is limited for low‐income women, researchers and providers should not assume a woman's current method is her method of choice.
Differentiated Bidders and Bidding Behavior in Procurement Auctions
Authors: Haruvy Ernan , Jap Sandy D.
Published: October 2012

Why do bidders in buyer-determined procurement auctions often bid above the lowest observed bid over the course of the auction? Are such bidding patterns meaningful? In this research, the authors propose that because bidders are differentiated in their value to the buyer and competition in these auctions is anonymous, bidders infer their potential quality advantage or disadvantage through their observation of competitive bids and incorporate this information into their responses and price bids. Using point-by-point bid data from two industrial procurement auctions, the authors show that bidders appear to be making inferences about their own implied quality differentials and adjust their bidding strategies and bidding aggression accordingly. Specifically, they find that high-quality bidders tend to be more aggressive in bidding against potentially higher-quality competition and less aggressive when bidding against potentially lower-quality competition. In contrast, low-quality bidders appear aggressive regardless of their implied quality in relation to the competition. The authors conclude with a discussion of implications for management and auction design.
On θ̂-pairs for maximal subgroups of a finite group
Authors: Chen Xiaoyu , Guo Wenbin
Published: October 2012

For a maximal subgroup
Skull ontogeny of Lycalopex culpaeus (Carnivora: Canidae): description of cranial traits and craniofacial sutures
Authors: Segura Valentina
Published: October 2012

Ontogenetic changes in the skull of
Investigation on Nylon 66 silicate nanocomposites modified under gamma radiation
Authors: Pradhan Rajiv , Bhattacharyya Arnab Shanker , Pramanik Nilay , Haldar Ramsankar , Niyogi Utpal Kumar , Khandal Rakesh Kumar , Bhowmik Shantanu
Published: October 2012

This investigation highlights the processing of Nylon 66 and the incorporation of nano-silicate into the Nylon 66 polymeric matrix. Further, radiation modification of Nylon 66 and nano-silicate dispersed Nylon 66 was carried out in order to essentially alter the physicochemical properties of the material. A combination of both the above methods of processing and modifying the neat Nylon 66 polymeric matrix provides an interesting aspect for studying the resultant effect on the variation in properties of the composite material over the virgin polymer. There was a significant improvement of physicothermal and physicomechanical properties when Nylon 66-silicate nanocomposites were further modified under gamma radiation, which was confirmed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and water absorption studies.
The influence of level of interfacial healing on the weld-line strengths of injection molded parts
Authors: Huang Chung-Ching , Wu Yu-Yi , Chang Hui-Tang , Yang Yi-Jen
Published: October 2012

Weld lines are commonly present within injection-molded plastic components and generally reduce strength. In designing a plastic part, the designer can often vary the wall thicknesses, or move the gate locations to position the weld line, so that its structural loading is minimized. By altering such variables as melt temperature, mold temperature, and packing pressure, slight increases in weld-line integrity can be achieved. These approaches often do not increase the part strength or performance to an acceptable level, resulting in the exclusion of numerous applications for plastic conversion. This study investigated a hot runner system, sequential valve gates, and heat degree, to achieve economical methods for predicting weld-line properties. By calculating melt front temperatures with MoldFlow analysis, we can predict the strength of the weld line according to the definition of “heat degree”, which is the effective cross-sectional area of the melt front multiplied by the temperature gradient. An effective cross-sectional area of the melt front is defined as the area of the temperature above the melting point. In contrast to the test result, when the “sum of heat degree” is lower than 1150 mm2 °C for PA6 (Mitsubishi 1030J) and 500 mm2 °C for polypropylene (PP) (FCFC K1012), the molecules cannot bond adequately at the interface of the melt fronts. Therefore, the mechanical property declines significantly.
CI-Methoden zur Koordination und Entkoppelung komplexer Systeme
Authors: Dürrbaum Axel , Kroll Andreas , Sommer Hanns-Jakob
Published: October 2012

Der Beitrag beschreibt die Konzeptentwicklung und das Auffinden von Koordinationsregeln für komplexe verkoppelte Systeme. Am Beispiel dieser Aufgabenstellung wird die Bedeutung der Computational Intelligence für die Systemtheorie erläutert.
Homogene Approximation der Paretofront bei mehrkriteriellen Kontrollproblemen
Authors: Rudolph Günter , Trautmann Heike , Schütze Oliver
Published: October 2012

Es werden mehrkriterielle evolutionäre Algorithmen (EMOA) für zwei- und höherdimensionale Probleme vorgestellt, die gleichmäßig verteilte Lösungen entlang der wahren Paretofront generieren. Dies ist insbesondere wichtig im Kontext mehrkriterieller Kontrollprobleme. Die Methodik beruht auf der Minimierung des gemittelten Hausdorff-Abstandes Δ
p
in Bezug auf die Paretofront. Die EMOA-Varianten werden vergleichend zu aktuellen Verfahren auf Benchmarkproblemen getestet.
A Comprehensive Genetic Approach for Improving Prediction of Skin Cancer Risk in Humans
Authors: Vazquez Ana I , de los Campos Gustavo , Klimentidis Yann C , Rosa Guilherme J M , Gianola Daniel , Yi Nengjun , Allison David B
Published: October 2012

Prediction of genetic risk for disease is needed for preventive and personalized medicine. Genome-wide association studies have found unprecedented numbers of variants associated with complex human traits and diseases. However, these variants explain only a small proportion of genetic risk. Mounting evidence suggests that many traits, relevant to public health, are affected by large numbers of small-effect genes and that prediction of genetic risk to those traits and diseases could be improved by incorporating large numbers of markers into whole-genome prediction (WGP) models. We developed a WGP model incorporating thousands of markers for prediction of skin cancer risk in humans. We also considered other ways of incorporating genetic information into prediction models, such as family history or ancestry (using principal components, PCs, of informative markers). Prediction accuracy was evaluated using the area under the receiver operating characteristic curve (AUC) estimated in a cross-validation. Incorporation of genetic information (i.e., familial relationships, PCs, or WGP) yielded a significant increase in prediction accuracy: from an AUC of 0.53 for a baseline model that accounted for nongenetic covariates to AUCs of 0.58 (pedigree), 0.62 (PCs), and 0.64 (WGP). In summary, prediction of skin cancer risk could be improved by considering genetic information and using a large number of single-nucleotide polymorphisms (SNPs) in a WGP model, which allows for the detection of patterns of genetic risk that are above and beyond those that can be captured using family history. We discuss avenues for improving prediction accuracy and speculate on the possible use of WGP to prospectively identify individuals at high risk.
Estimate of the Spontaneous Mutation Rate in Chlamydomonas reinhardtii
Authors: Ness Rob W , Morgan Andrew D , Colegrave Nick , Keightley Peter D
Published: October 2012

The nature of spontaneous mutations, including their rate, distribution across the genome, and fitness consequences, is of central importance to biology. However, the low rate of mutation has made it difficult to study spontaneous mutagenesis, and few studies have directly addressed these questions. Here, we present a direct estimate of the mutation rate and a description of the properties of new spontaneous mutations in the unicellular green alga Chlamydomonas reinhardtii. We conducted a mutation accumulation experiment for ∼350 generations followed by whole-genome resequencing of two replicate lines. Our analysis identified a total of 14 mutations, including 5 short indels and 9 single base mutations, and no evidence of larger structural mutations. From this, we estimate a total mutation rate of 3.23 × 10−10/site/generation (95% C.I. 1.82 × 10−10 to 5.23 × 10−10) and a single base mutation rate of 2.08 × 10−10/site/generation (95% C.I., 1.09 × 10−10 to 3.74 × 10−10). We observed no mutations from A/T → G/C, suggesting a strong mutational bias toward A/T, although paradoxically, the GC content of the C. reinhardtii genome is very high. Our estimate is only the second direct estimate of the mutation rate from plants and among the lowest spontaneous base-substitution rates known in eukaryotes.
Sister Chromatids Segregate at Mitosis Without Mother–Daughter Bias in Saccharomyces cerevisiae
Authors: Keyes Brice E , Sykes Kenneth D , Remington Courtney E , Burke Daniel J
Published: October 2012

There is evidence accumulating for nonrandom segregation of one or more chromosomes during mitosis in different cell types. We use cell synchrony and two methods to show that all chromatids of budding yeast segregate randomly and that there is no mother–daughter bias with respect to Watson and Crick-containing strands of DNA.
Impact of Employment Contract Changes on Workers' Quality of Working Life, Job Insecurity, Health and Work‐related Attitudes
Authors: Wagenaar Alfred F. , Kompier Michiel A.J. , Houtman Irene L.D. , van den Bossche Seth N. J. , Taris Toon W.
Published: October 2012

Impact of Employment Contract Changes on Workers' Quality of Working Life, Job Insecurity, Health and Work‐related Attitudes: Alfred F. WAGE‐NAAR, et al. Behavioural Science Institute, Department of Work and Organizational Psychology, Radboud University Nijmegen, The Netherlands—

Objectives

Changes in employment contracts may impact the quality of working life, job insecurity, health and work‐related attitudes. We examined the validity of two partly competing theoretical approaches. Based upon a segmentation approach, we expected no change in scores among stable trajectories, whereas upward trajectories were expected to be for the better and downward trajectories to be for the worse (Hypothesis 1). As turnover theories suggest that this hypothesis may only apply to workers who do not change employer, we also examined these contract trajectories stratified for a change of employer (Hypothesis 2). Methods and Results: Drawing on the 2007 and 2008 waves of the Netherlands Working Conditions Cohort Study (N=9,688), repeated measures analysis of covariance showed little across‐time change in the criterion variables, thus largely disconfirming our first hypothesis. These results could (at least partly) be explained by employer change; this was generally associated with improved scores among all contract trajectories (Hypothesis 2). However, workers receiving a less stable contract from the same employer were found to be at risk for health and well‐being problems.

Conclusions

Segmentation theory‐based assumptions on contract trajectories primarily apply to stable and downward contract trajectories at the same employer, whereas assumptions from turnover theories better apply to contract trajectories combined with a change of employer. Future research should focus more closely on factors predicting “involuntary” downward trajectories into precarious temporary employment or unemployment.