bluuebunny/crossref_metadata_2025 huggingface dataset:
Why Do Aortas Cleave or Dilate? Clues from an Electronic Scanning Microscopy Study in Human Ascending Aortas
Authors: Borges Luciano Figueiredo , Blini João Paulo Forato , Dias Ricardo Ribeiro , Gutierrez Paulo Sampaio
Published: December 2013

In ascending aorta aneurysms (AscAA) the whole vessel wall dilates, while in aortic dissections (AD) the wall cleaves into two sheets. Both may present fine elastic fragmentation and a decrease in collagen. We analyzed whether alterations in the three-dimensional structure of these fibers could be involved in the pathogenesis of AscAA/AD. Specimens obtained at surgery for these diseases (n = 4 for each) and on coronary artery bypass surgery (controls, n = 4) were submitted to treatments which either preserve collagen or the elastic structure. These samples were examined by scanning electron microscopy. In all groups most of the collagen fibers were packed, forming laminar structures very similar to the elastic lamellae. In AscAA/AD, the fibers showed signs of degradation and/or fragmentation. Elastic tissue was distributed in large sheets with fenestrations, with smaller branches between them. In 1 of the dissection cases and 2 of the aneurysm cases elastic sheet fragmentation, which under light microscopy seems to be located at random, had a pattern of clefts which were irregular but approximately transversal to the main axis of the wall. The recognition of this pattern and the degradation/fragmentation of collagen and elastic fibrils facilitates understanding of why the wall is weak and affected by aneurysms and dissections.
Rethinking library instruction:
Authors: Lacy Meagan , Chen Hsin-liang
Published: December 2013

Given the growing pressure on academic institutions and, by extension, academic libraries to establish student learning outcomes and demonstrate their impact on student learning, researchers at Indiana University – Purdue University Indianapolis (IUPUI) explored how outcome-based instructional design can be used to 1) collect student data, 2) assess student learning, and 3) improve instruction. Two surveys were distributed to 59 undergraduate students who were enrolled in an introductory composition course at IUPUI. Because previous studies (e.g. Ford, Miller and Moss 2005) have linked human individual differences with web search strategy, the first survey collected information about the students’ demographic features. The second survey, a search log, collected information about the sources that students chose, the search terms they used and the strategies they employed in order to complete their research. The students submitted their first survey after the instructional session and the second survey after they completed their research project. Using this data, the researchers examined whether students’ achievement could be associated with their personal characteristics and/or the librarian’s instruction. In contrast to Ford, Miller and Moss’s study (2005), no significant relationships were found between students’ personal characteristics and their search behaviour. However, after receiving instruction, all students were able to create keywords and structure them into search queries using Boolean operators. These results suggest that outcome-based instructional design is an effective pedagogical method for gathering assessment data and that the survey instrument was a useful tool for assessing this outcome - by providing both a measurement of student learning and a means of evaluating the librarian’s instruction.
Faculty and student perceptions and behaviours related to information literacy:
Authors: Ganley Barbara Jane , Gilbert Amy , Rosario Dianne
Published: December 2013

This pilot study was developed to determine if the University’s students were proficient in information literacy (IL) based on the requisite skills defined by ALA (2000), to define faculty and student perceptions and behaviours related to IL and to test an evaluation rubric using empirical inquiry and triangulated methods. Findings suggested that not all students (n=164) had satisfactory IL skills even at the senior student level. While 4th year college students (seniors n=91) fared better on an IL survey when compared to 1st year college students (freshmen n=53), analysis of the senior students’ theses led researchers to believe that students were most likely not skilled in this area, and had an inflated opinion of their own IL abilities. Overall, students felt they were less IL challenged compared to the faculty’s (n=55) observation of the IL challenges experienced by the students. Students’ self-assessment of their literacy skills may have been coloured by the propensity of the faculty to over-edit students’ papers rather than simply providing constructive feedback, thus altering the natural end result. These authors used a triangulated approach including thesis review, comparisons between student and faculty survey responses and comparison of findings from the theses and the student and faculty surveys. Findings and discussion of methodology will hopefully provide valuable lessons for those interested in assessing students’ IL.
Faculty perceptions of students' information literacy skills competencies
Authors: Dubicki Eleonora
Published: December 2013

This research study investigates academic faculty perceptions of information literacy at eight New Jersey higher educational institutions. The study examines the value and importance faculty place on information literacy (IL), the infusion of IL into curricular learning outcomes and an assessment of the competency levels students achieve in mastering IL skills. This study adds to the research in the field as a multi-institutional study conducted at both two-year and four-year institutions, investigating full-time and part-time faculty perspectives. Findings are based on results from an online survey, with a total of 353 usable responses. Overall, faculty familiarity with IL concepts was high; faculty are overwhelmingly supportive of IL and are incorporating these skills into learning outcomes for their courses; and there are strong expectations of students’ achieving IL skills by graduation, but faculty perceptions are that students fall short of mastering those skills by the end of their programmes.
A new species of Erythroxylum (Erythroxylaceae) from the Brazilian semiarid region
Authors: Loiola Maria Iracema Bezerra
Published: December 2013

Erythroxylum angelicae, a new species of Erythroxylum sect. Archerythroxylum, is described and illustrated. This species occurs in “Carrasco” vegetation of the state of Ceará, northeastern Brazil. It is recognized by the persistent cataphylls, non-striated, long-triangular, and palleaceous; stipules non-striated, 3-setulose; flowers subsessile, calyx lobes triangular, and styles free. Affinity relationships with other species of Erythroxylum are also presented and discussed.
Revision of the neotropical jumping plant-louse genus Mastigimas (Hemiptera, Psylloidea) attacking Cedrela and Toona species (Meliaceae)
Authors: Burckhardt Daniel , Queiroz Dalva L. , Drohojowska Jowita
Published: December 2013

The small Neotropical genus Mastigimas with five described species is revised. Three new species are added: Mastigimas colombianus sp. n. from Colombia on Cedrela montana, M. drepanodis sp. n. from Brazil (Paraná) on C. fissilis and M. reseri sp. n. from Jamaica collected in light traps. Another two species are recorded from Brazil and Colombia, respectively, which are not formally described due to insufficient material. The new species are described, and illustrations and identification keys are provided for all species. The last instar immatures are described for five species. The phylogeny within Mastigimas is analysed, and the biogeographic and host plant relationships are discussed.
Ranging through Shallow Semitransparent Media with Polarization Lidar
Authors: Mitchell Steven E. , Thayer Jeffrey P.
Published: December 2013

A new approach to shallow depth measurement (<2 m) using polarization lidar is presented. The transmitter consists of a 532-nm linearly polarized laser coupled with conditioning and polarization optics. The prototype lidar evaluates the differing polarization attributes of signals scattered from semitransparent media surfaces, simultaneously receiving signals polarized in the planes parallel and perpendicular to the transmitted laser signal via dual photomultiplier tubes. In the event the first surface nearly preserves the incident polarization and the second surface depolarizes the incident energy, signals scattered from the second surface are isolated from the first by a polarization analyzer in the receiver. This approach translates depth measurements into the conditions of single surface range measurements, giving the ability to resolve extremely shallow depths (e.g., 1 cm) independent of laser or detector pulse widths. This approach can circumvent dead time issues in photon-counting systems and can be applied to extremely shallow and deeper waters for depth determination. Furthermore, the approach provides an estimate of the first surface linear depolarization ratio, enabling differentiation between surfaces with variable scattering properties. Using this technique to acquire range-resolved observations through shallow semitransparent media to measure depth removes the dependency on sophisticated and, subsequently, costly lidar components by becoming independent of system bandwidth. The limiting factor in-depth resolution is driven only by the timing resolution of the time-to-digital converter. This approach allows for the use of common lasers, optics, and detector equipment, making it comparatively cheaper and less complex while achieving vast improvement in the accuracy and precision of shallow depth measurements.
Observed Hurricane Wind Speed Asymmetries and Relationships to Motion and Environmental Shear
Authors: Uhlhorn Eric W. , Klotz Bradley W. , Vukicevic Tomislava , Reasor Paul D. , Rogers Robert F.
Published: December 2013

Wavenumber-1 wind speed asymmetries in 35 hurricanes are quantified in terms of their amplitude and phase, based on aircraft observations from 128 individual flights between 1998 and 2011. The impacts of motion and 850–200-mb environmental vertical shear are examined separately to estimate the resulting asymmetric structures at the sea surface and standard 700-mb reconnaissance flight level. The surface asymmetry amplitude is on average around 50% smaller than found at flight level, and while the asymmetry amplitude grows in proportion to storm translation speed at the flight level, no significant growth at the surface is observed, contrary to conventional assumption. However, a significant upwind storm-motion-relative phase rotation is found at the surface as translation speed increases, while the flight-level phase remains fairly constant. After removing the estimated impact of storm motion on the asymmetry, a significant residual shear direction-relative asymmetry is found, particularly at the surface, and, on average, is located downshear to the left of shear. Furthermore, the shear-relative phase has a significant downwind rotation as shear magnitude increases, such that the maximum rotates from the downshear to left-of-shear azimuthal location. By stratifying observations according to shear-relative motion, this general pattern of a left-of-shear residual wind speed maximum is found regardless of the orientation between the storm’s heading and shear direction. These results are quite consistent with recent observational studies relating western Pacific typhoon wind asymmetries to environmental shear. Finally, changes in wind asymmetry over a 5-day period during Hurricane Earl (2010) are analyzed to understand the combined impacts of motion and the evolving shear.
The Canadian Critical Care Nutrition Guidelines in 2013
Authors: Dhaliwal Rupinder , Cahill Naomi , Lemieux Margot , Heyland Daren K.
Published: December 2013

Clinical practice guidelines (CPGs) are systematically developed statements to assist practitioners and patient decisions about appropriate healthcare for specific clinical circumstances, and are designed to minimize practice variation, improve costs, and improve clinical outcomes. The Canadian Critical Care Practice Guidelines (CCPGs) were first published in 2003 and most recently updated in 2013. A total of 68 new randomized controlled trials were identified since the last version in 2009, 50 of them published between 2009 and 2013. The remaining articles were trials published before 2009 but were not identified in previous iterations of the CCPGs. For clinical practice guidelines to be useful to practitioners, they need to be up‐to‐date and be reflective of the current body of evidence. Herein we describe the process by which the CCPGs were updated. This process resulted in 10 new sections or clinical topics. Of the old clinical topics, 3 recommendations were upgraded, 4 were downgraded, and 27 remained the same. To influence decision making at the bedside, these updated guidelines need to be accompanied by active guideline implementation strategies. Optimal implementation strategies should be guided by local contextual factors including barriers and facilitators to best practice recommendations. Moreover, evaluating and monitoring performance, such as participating in the International Nutrition Survey of practice, should be part of any intensive care unit's performance improvement strategy. The active implementation of the updated CCPGs may lead to better nutrition care and improved patient outcomes in the critical care setting.
Identification of Bruton’s tyrosine kinase as a therapeutic target in acute myeloid leukemia
Authors: Rushworth Stuart A. , Murray Megan Y. , Zaitseva Lyubov , Bowles Kristian M. , MacEwan David J.
Published: December 2013

Key Points

Inhibition of Bruton’s tyrosine kinase is as effective in vitro against AML as chronic lymphocytic leukemia. Ibrutinib shows activity in AML because Bruton’s tyrosine kinase is constitutively active.
BioVector, a flexible system for gene specific-expression in plants
Authors: Wang Xu , Fan Chengming , Zhang Xiaomei , Zhu Jinlong , Fu Yong-Fu
Published: December 2013

Background

Functional genomic research always needs to assemble different DNA fragments into a binary vector, so as to express genes with different tags from various promoters with different levels. The cloning systems available bear similar disadvantages, such as promoters/tags are fixed on a binary vector, which is generally with low cloning efficiency and limited for cloning sites if a novel promoter/tag is in need. Therefore, it is difficult both to assemble a gene and a promoter together and to modify the vectors in hand. Another disadvantage is that a long spacer from recombination sites, which may be detrimental to the protein function, exists between a gene and a tag. Multiple GATEWAY system only resolves former problem at the expense of very low efficiency and expensive for multiple LR reaction.

Results

To improve efficiency and flexibility for constructing expression vectors, we developed a platform, BioVector, by combining classical restriction enzyme/ligase strategy with modern Gateway DNA recombination system. This system included a series of vectors for gene cloning, promoter cloning, and binary vector construction to meet various needs for plant functional genomic study.

Conclusion

This BioVector platform makes it easy to construct any vectors to express a target gene from a specific promoter with desired intensity, and it is also waiting to be freely modified by researchers themselves for ongoing demands. This idea can also be transferred to the different fields including animal or yeast study.
Alteration of choroidal thickness in a case of carotid cavernous fistula: a case report and a review of the literature
Authors: Shinohara Yoichiro , Kashima Tomoyuki , Akiyama Hideo , Kishi Shoji
Published: December 2013

Background

To measure the alterations of the choroidal thickness in Carotid cavernous fistula (CCF) using enhanced depth imaging optical coherence tomography (EDI-OCT).

Case presentation

A 64-year-old woman was referred to us for redness, exophthalmos and visual disturbance in her right eye. She was diagnosed with CCF by magnetic resonance imaging (MRI) and magnetic resonance angiography.

Observations; Embolization resulted in improvement of ocular symptoms, and there was a reduction of the subfoveal choroidal thickness in the right eye from 351 μm preoperatively to 142 μm postoperatively in EDI-OCT.

Conclusion

EDI-OCT demonstrated that the choroidal thickness increases occurred due to congestion in a CCF case.
PASS-predicted Vitex negundo activity: antioxidant and antiproliferative properties on human hepatoma cells-an in vitro study
Authors: Kadir Farkaad A , Kassim Normadiah M , Abdulla Mahmood A , Yehye Wageeh A
Published: December 2013

Background

Hepatocellular carcinoma is a common type of tumour worldwide with a high mortality rate and with low response to current cytotoxic and chemotherapeutic drugs. The prediction of activity spectra for the substances (PASS) software, which predicted that more than 300 pharmacological effects, biological and biochemical mechanisms based on the structural formula of the substance was efficiently used in this study to reveal new multitalented actions forVitex negundo(VN) constituents.

Methods

Experimental studies based on antioxidant and antiproliferative assays verified the predictions obtained by the PASS-predicted design strategy. Antioxidant activity of VN extract was studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric reducing or antioxidant power (FRAP) assays. The antiproliferative activity of VN extract against WRL68 and HepG2 was investigated based on methylthiazol tetrazolium (MTT) spectrophotometric assay.

Results

VN extract showed 79.43% inhibition of DPPH stable radical with IC5013.31 ± 0.18 μg/ml. This inhibition was too closed to butylated hydroxyl toluene (BHT) 82.53% (IC5013.8 ± 0.14) and gallic acid 89.51% (IC503.1 ± 0.08). VN extract exhibited the strongest free radical scavenging power compared with two commercial antioxidants, BHT and ascorbic acid. VN increased the activities of antioxidant enzymes in normal embryonic liver cells (WRL68) including, superoxide dismutase (SOD) and glutathione peroxidase (GPX) compared with to H2O2group. The ethanolic extract of VN showed cytotoxicity to HepG2 cells in a dose and time-dependent manner with IC5066.46 μg/ml, 57.36 μg/ml and 65.12 μg/ml at 24, 48, and 72-hours incubation respectively, with no sensitivity in WRL68 cells. This was associated with significant elevation in lactate dehydrogenase (LDH) release in HepG2 cells. In addition, the activation of caspase-3 enzyme suggesting that the observed cytotoxicity was mediated via an intrinsic apoptosis pathway.

Conclusions

PASS-predicted plant activity could efficiently help in selecting a promising pharmaceutical leads with high accuracy and required antioxidant and antiproliferative properties. This is the first report on PASS-predicted VN activity.
Factors associated with consulting a dietitian for diabetes management: a cross-sectional study
Authors: Alameddine Mohamad , Nasreddine Lara , Hwalla Nahla , Mourad Yara , Shoaib Hikma , Mousa Dana , Naja Farah
Published: December 2013

Background

Type 2 Diabetes (T2D) has reached epidemic levels in the Middle East region. Despite evidence that it improves health outcomes and saves health costs, dietary counseling for T2D remains grossly under-investigated in this region. The aim of this study was to assess the frequency and determinants of use of dietary counseling services by T2D patients in Lebanon and recommend corrective measures that may guide the planning, organization and delivery of care for chronic diseases in general and diabetes care in particular.

Methods

A non-experimental cross-sectional design was utilized to survey outpatients with T2D in two major health centers in Lebanon. Patients diagnosed with T2D were invited to complete a questionnaire consisting of five sections: socio-demographic characteristics, disease attributes, patients’ perceptions regarding T2D management, practice of lifestyle modifications, and referral by a physician to a dietitian. The outcome of interest was the use of dietary counseling services by T2D patients at least once since their diagnosis. Descriptive statistics and logistic regression analyses were used to evaluate the frequency and determinants of dietary counseling services utilization.

Results

A total of 332 T2D patients completed the questionnaire (response rate 94.6%). Although 75% of study participants believed that dietitians can assist them in changing their dietary habits, only 38% had consulted with a dietitian. Among study participants, only 34% were referred to a dietitian by their physician. The main determinants of the use of dietary counseling services were referral by a physician (OR: 112.25; 95% CI = 42.74-294.84), the presence of outpatient social or private health insurance (OR: 5.86; 95% CI = 2.40-14.25) and the belief that a dietitian can assist in changing dietary habits (OR: 3.74; 95% CI = 1.33-10.54).

Conclusions

The findings of this study show suboptimal use of dietary counseling services by T2D patients in Lebanon. Key determinants were physicians’ referral, financial support for outpatient care, and patients’ belief in the usefulness of dietary counseling. Suggested interventions entail enhancing the planning and organization of care through inter-professional collaboration between physicians and dietitians; promoting public financing for high quality outpatient care that includes dietary counseling; and promoting the value of dietary counseling and improving the public image of dietitians.
Nurses’ self-efficacy and practices relating to weight management of adult patients: a path analysis
Authors: Zhu Da Q , Norman Ian J , While Alison E
Published: December 2013

Background

Health professionals play a key role in the prevention and treatment of excess weight and obesity, but many have expressed a lack of confidence in their ability to manage obese patients with their delivery of weight-management care remaining limited. The specific mechanism underlying inadequate practices in professional weight management remains unclear. The primary purpose of this study was to examine a self-efficacy theory-based model in understanding Registered Nurses’ (RNs) professional performance relating to weight management.

Methods

A self-report questionnaire was developed based upon the hypothesized model and administered to a convenience sample of 588 RNs. Data were collected regarding socio-demographic variables, psychosocial variables (attitudes towards obese people, professional role identity, teamwork beliefs, perceived skills, perceived barriers and self-efficacy) and professional weight management practices. Structural equation modeling was conducted to identify correlations between the above variables and to test the goodness of fit of the proposed model.

Results

The survey response rate was 71.4% (n = 420). The respondents reported a moderate level of weight management practices. Self-efficacy directly and positively predicted the weight management practices of the RNs (β = 0.36,p < 0.01), and fully or partially mediated the relationships between perceived skills, perceived barriers, professional role identity and teamwork beliefs and weight management practices. The final model constructed in this study demonstrated a good fit to the data [χ2(14) =13.90,p = 0.46; GFI = 0.99; AGFI = 0.98; NNFI = 1.00; CFI = 1.00; RMSEA = 0.00; AIC = 57.90], accounting for 38.4% and 43.2% of the variance in weight management practices and self-efficacy, respectively.

Conclusions

Self-efficacy theory appears to be useful in understanding the weight management practices of RNs. Interventions targeting the enhancement of self-efficacy may be effective in promoting RNs’ professional performance in managing overweight and obese patients.
Estimating the number of competing terminals without a state variation detector in wireless LAN
Authors: Lim Jaechan , Kim Taejin , Hong Daehyoung
Published: December 2013

Estimating the number of competing terminals n (who wish to transmit a packet at the same time) in the IEEE 802.11 system is important for system throughput performance because optimal back-off window size needs to be selected based on n. Therefore, as a new approach for estimating n, we propose H infinity filter that does not need a state variation detector as opposed to the cases of previously proposed approaches. The state variation detector’s flaw is incurring tracking latency in addition to the side effect of increased computational cost. All previously proposed approaches demand the employment of the state variation detector to detect the variation of n in the IEEE 802.11 system. By employing H infinity filter, we show improved throughput performance of the system compared to that of previously proposed approaches (e.g., the Kalman filter and particle filter) based on the improved performance in tracking n. In this paper, we justify the superiority of the proposed approach in the terms of tracking performance, throughput performance, and computational complexity.
Acquired drug resistance conferred by a KRAS gene mutation following the administration of cetuximab: a case report
Authors: Osumi Hiroki , Matsusaka Satoshi , Shinozaki Eiji , Suenaga Mitsukuni , Mingyon Mun , Saiura Akio , Ueno Masashi , Mizunuma Nobuyuki , Yamaguchi Toshiharu
Published: December 2013

Background

Although a number of studies have reported acquired drug resistance due to administration of epidermal growth factor receptor antibody inhibitors, the underlying causes of this phenomenon remain unclear.

Case presentation

Here we report a case of a 75-year-old man with liver metastasis at 3 years after a successful transverse colectomy to treat KRAS wild-type colorectal cancer. While initial administration of epidermal growth factor receptor inhibitors proved effective, continued use of the same treatment resulted in new peritoneal seeding. An acquired KRAS mutation was found in a resected tissue specimen from one such area. This mutation, possibly caused by administration of epidermal growth factor receptor inhibitors, appears to have conferred drug resistance.

Conclusion

The present findings suggest that administration of epidermal growth factor receptor inhibitors results in an acquired KRAS mutation that confers drug resistance.
Foods with added fiber improve stool frequency in individuals with chronic kidney disease with no impact on appetite or overall quality of life
Authors: Salmean Younis A , Zello Gordon A , Dahl Wendy J
Published: December 2013

Background

Fiber intake may be low in individuals with chronic kidney disease (CKD) due to diet restriction and/or poor appetite associated with uremic symptoms, contributing to constipation and reduced quality of life. This report describes the effects of foods with added fiber on gastrointestinal function and symptoms, clinical markers, and quality of life in CKD patients.

Findings

Adults with CKD (n = 15; 9 F, 6 M; 66 ± 15 y) were provided with cereal, cookies and snack bars without added fiber for 2 weeks, followed by similar foods providing 23 g/d of added fiber for 4 weeks, to incorporate into their usual diets. Participants completed the Kidney Disease Quality of Life (KDQOL-36) questionnaire, the Simplified Nutritional Appetite Questionnaire (SNAQ) and the Epworth Sleepiness Scale (ESS) bi-weekly, the Gastrointestinal Symptom Rating Scale (GSRS) weekly, and daily stool frequency and compliance. Control and intervention serum cholesterol and glucose were assessed. Providing 23 g/d of added fiber increased stool frequency (1.3 ± 0.2 to 1.6 ± 0.2 stools/d; P = 0.02), decreased total cholesterol (175 ± 12 to 167 ± 11 mg/dL; P = 0.02) and improved TC:HDL ratio (4.0 ± 0.3 to 3.7 ± 0.2; P = 0.02). GSRS and SNAQ scores did not change, but SNAQ scores suggested poor appetite in 7 participants with or without added fiber. KDQOL Mental Health Composite decreased from 53 ± 2 to 48 ± 2 (P = 0.01) while Physical Health Composite increased from 31 ± 2 to 35 ± 3 (P = 0.02), with no change in overall QOL. The ESS score decreased from 10 ± 1 to 8 ± 1 (P = 0.04).

Conclusion

Consuming foods with added fiber may be an effective means of increasing fiber intakes, improving stool frequency, and lipid profile in individuals with CKD.

Trial registration

ClinicalTrials.gov, # NCT01842087
Replenishment of the B cell compartment after doxorubicin-induced hematopoietic toxicity is facilitated by STAT1
Authors: Datta Sebak , Parajuli Nirmala , Tymoszuk Piotr , Ottina Eleonora , Parson Walther , Sgonc Roswitha , Villunger Andreas , Doppler Wolfgang
Published: December 2013

STAT1 serves as an important regulator in the response to pathogens, oncogenic transformation, and genotoxic insults. It exerts these effects by shaping the innate and adaptive immune response and by participating in genotoxic stress pathways, leading to apoptosis and inhibition of cell proliferation. We have investigated the role of STAT1 in hematopoietic toxicity induced by doxorubicin in STAT1-proficient and -deficient mice. Whereas the early genotoxic effect of doxorubicin did not depend on STAT1, expression of STAT1 was required for efficient B lymphocyte repopulation in the recovery phase. We found a lower abundance of lymphocyte precursors in the BM of STAT1-deficient animals, which was particularly evident after doxorubicin-induced hematopoietic toxicity. In accordance, colony-forming assays with STAT1-deficient BM cells revealed a decreased number of pre-B colonies. Differentiation from the pro-B to the pre-B stage was not affected, as demonstrated by unaltered differentiation of purified B cell precursors from BM in the presence of IL-7. With the exception of Sca-1, expression of genes implicated in early lymphocyte development in pro-B cells did not depend on STAT1. Our findings indicate a specific requirement for STAT1 in lymphoid development before differentiation to pre-B cells, which becomes particularly apparent in the recovery phase from doxorubicin-induced hematopoietic toxicity.
Regulation of the mucosal phenotype in dendritic cells by PPARγ: role of tissue microenvironment
Authors: Tuna Halide , Avdiushko Rita G , Sindhava Vishal J , Wedlund Leia , Kaetzel Charlotte S , Kaplan Alan M , Bondada Subbarao , Cohen Donald A
Published: December 2013

Mucosal DCs play a critical role in tissue homeostasis. Several stimuli can induce a mucosal phenotype; however, molecular pathways that regulate development of mucosal DC function are relatively unknown. This study sought to determine whether PPARγ contributes to the development of the “mucosal” phenotype in mouse DCs. Experiments demonstrated that PPARγ activation in BMDCs induced an immunosuppressive phenotype in which BMDCs had reduced expression of MHC class II and costimulatory molecules, increased IL-10 secretion, and reduced the ability to induce CD4 T cell proliferation. Activation of PPARγ enhanced the ability of BMDC to polarize CD4 T cells toward iTregs and to induce T cell expression of the mucosal homing receptor, CCR9. Activation of PPARγ increased the ability of BMDCs to induce T cell-independent IgA production in B cells. BMDCs from PPARγΔDC mice displayed enhanced expression of costimulatory molecules, enhanced proinflammatory cytokine production, and decreased IL-10 synthesis. Contrary to the inflammatory BMDC phenotype in vitro, PPARγΔDC mice showed no change in the frequency or phenotype of mDC in the colon. In contrast, mDCs in the lungs were increased significantly in PPARγΔDC mice. A modest increase in colitis severity was observed in DSS-treated PPARγΔDC mice compared with control. These results indicate that PPARγ activation induces a mucosal phenotype in mDCs and that loss of PPARγ promotes an inflammatory phenotype. However, the intestinal microenvironment in vivo can maintain the mucosal DC phenotype of via PPARγ-independent mechanisms.
Ion channels contribute to the regulation of cell sheet forces during Drosophila dorsal closure
Authors: Hunter Ginger L. , Crawford Janice M. , Genkins Julian Z. , Kiehart Daniel P.
Published: December 2013

We demonstrate that ion channels contribute to the regulation of dorsal closure in Drosophila, a model system for cell sheet morphogenesis. We find that Ca2+ is sufficient to cause cell contraction in dorsal closure tissues, as UV-mediated release of caged Ca2+ leads to cell contraction. Furthermore, endogenous Ca2+ fluxes correlate with cell contraction in the amnioserosa during closure, whereas the chelation of Ca2+ slows closure. Microinjection of high concentrations of the peptide GsMTx4, which is a specific modulator of mechanically gated ion channel function, causes increases in cytoplasmic free Ca2+ and actomyosin contractility and, in the long term, blocks closure in a dose-dependent manner. We identify two channel subunits, ripped pocket and dtrpA1 (TrpA1), that play a role in closure and other morphogenetic events. Blocking channels leads to defects in force generation via failure of actomyosin structures, and impairs the ability of tissues to regulate forces in response to laser microsurgery. Our results point to a key role for ion channels in closure, and suggest a mechanism for the coordination of force-producing cell behaviors across the embryo.
The Xenopus homologue of Down syndrome critical region protein 6 drives dorsoanterior gene expression and embryonic axis formation by antagonising polycomb group proteins
Authors: Li Hong-Yan , Grifone Raphaëlle , Saquet Audrey , Carron Clémence , Shi De-Li
Published: December 2013

Mesoderm and embryonic axis formation in vertebrates is mediated by maternal and zygotic factors that activate the expression of target genes. Transcriptional derepression plays an important role in the regulation of expression in different contexts; however, its involvement and possible mechanism in mesoderm and embryonic axis formation are largely unknown. Here we demonstrate that XDSCR6, a Xenopus homologue of human Down syndrome critical region protein 6 (DSCR6, or RIPPLY3), regulates mesoderm and embryonic axis formation through derepression of polycomb group (PcG) proteins. Xdscr6 maternal mRNA is enriched in the endoderm of the early gastrula and potently triggers the formation of dorsal mesoderm and neural tissues in ectoderm explants; it also dorsalises ventral mesoderm during gastrulation and induces a secondary embryonic axis. A WRPW motif, which is present in all DSCR6 homologues, is necessary and sufficient for the dorsal mesoderm- and axis-inducing activity. Knockdown of Xdscr6 inhibits dorsal mesoderm gene expression and results in head deficiency. We further show that XDSCR6 physically interacts with PcG proteins through the WRPW motif, preventing the formation of PcG bodies and antagonising their repressor activity in embryonic axis formation. By chromatin immunoprecipitation, we demonstrate that XDSCR6 releases PcG proteins from chromatin and allows dorsal mesoderm gene transcription. Our studies suggest that XDSCR6 might function to sequester PcG proteins and identify a novel derepression mechanism implicated in embryonic induction and axis formation.
Conveying principles of embryonic development by metaphors from daily life
Authors: Shilo Ben-Zion
Published: December 2013

How can the revolution in our understanding of embryonic development and stem cells be conveyed to the general public? Here, I present a photographic approach to highlight scientific concepts of pattern formation using metaphors from daily life, displaying pairs of images of embryonic development and the corresponding human analogy. By making the viewer ‘feel’ like a cell within a developing embryo, the personal experiences resonate with the scientific concepts, facilitating a new type of appreciation.
Intramolecular Electron Transfer of [Ni–Fe]-Hydrogenase Monitored by Spectroelectrochemistry with a Porphyrin Indicator
Authors: Nishizawa Shaw , Asakura Noriyuki
Published: December 2013

A method based on spectroelectrochemistry to monitor intramolecular electron transfer in [Ni–Fe]-hydrogenase was developed. The electron transfer generated a color change in manganese–tetra(4-pyridyl)porphyrin (MnTPyP), and time-resolved measurement of the spectral change allowed determination of the intramolecular electron transfer rate. A MnTPyP–hydrogenase–electrode was prepared as a model system to monitor an intramolecular electron transfer, and spectroelectrochemical measurement was carried out. An intramolecular electron transfer of [Ni–Fe]-hydrogenase, which is a rate between distal [4Fe–4S] and [Ni–Fe], was measured by the developed system.
Technical Report: Development of a Piezoelectric Inkjet Dopant Delivery Device for an Atmospheric Pressure Photoionization Source with Liquid Chromatography/Mass Spectrometry
Authors: Amad Ma'an H. , Li Er Qiang , Sioud Salim , Thoroddsen Sigurdur T.
Published: December 2013

This paper describes a simple, robust and integrated piezoelectric actuated printhead as a dopant delivery system for atmospheric pressure photoionization with liquid chromatography/mass spectrometry. The newly designed dopant delivery system avoids problems associated with traditional liquid delivery systems such as solvent immiscibility, backpressure and increased post-column dead volume issues. The performance of the new device was tested and evaluated using chlorobenzene as a dopant with a test mixture consisting of 18 different polycyclic aromatic hydrocarbons (PAHs). The results show that the new system works robustly at low dopant consumption level (1.6 uL min−1), consuming only approximately 5% of the amount used by conventional sources. The low dopant consumption has resulted in up to a 20-fold reduction in signal intensity of tested PAH molecules, but has led to less presence of background cluster ions and dopant trace contaminant background ions in the source area. Consequently, all tested PAHs were detected with excellent signal-to-noise ratio with at least two- to ten-fold improvements in the limit of detection and quantification compared to those obtained with traditional dopant assistance using a post-column addition method.
Identification of Potential Lung Cancer Biomarkers by Liquid Chromatography Tandem Mass Spectrometry-Based Proteomics Analysis of Secretomes of Two Lung Cancer Cell Lines
Authors: Shevchenko Valeriy E. , Kovalev Sergey V. , Arnotskaya Natalia E. , Kudryavtsev Igor A.
Published: December 2013

A label-free nano-liquid chromatography tandem mass spectrometry proteomics analysis on the conditioned media (CM) of two lung cancer cell lines of different histological backgrounds to identify secreted or membrane-bound proteins as novel lung cancer biomarkers was performed. Five hundred and seventy seven proteins were identified and 38% of them were classified as extracellular or membrane-bound. For the search of potential biomarkers of lung cancer a series of selection criteria were proposed. We detected known or putative lung cancer markers. In addition, 40 novel proteins were identified, whose role as biomarkers of lung cancer should be explored further.
Συγκριτική έρευνα νεφροτοξότητας του na-meglumine-diatrizoate (urografin) και του iohexol (omntraque)
Authors: Δήμου Λευκοθέα
Published: December 2013

ΕΡΕΥΝΗΘΗΚΑΝ ΕΙΚΟΣΙ (20) ΑΡΡΩΣΤΟΙ 13 ΓΥΝΑΙΚΕΣ ΚΑΙ 7 ΑΝΔΡΕΣ ΗΛΙΚΙΑΣ 37-76 ΧΡΟΝΩΝΜΕ ΙΚΑΝΟΠΟΙΗΤΙΚΗ ΝΕΦΡΙΚΗ ΛΕΙΤΟΥΡΓΙΑ (ΚΡΕΑΤΙΝΙΝΗ ΟΡΟΥ < 130 MMOL/ΛΙΤΡΟ) ΓΙΑ ΕΝΔΕΧΟΜΕΝΕΣ ΝΕΦΡΙΚΕΣ ΕΠΙΠΤΩΣΕΙΣ ΜΕΤΑ ΧΟΡΗΓΗΣΗ ΙΟΝΙΚΟΥ ΚΑΙ ΜΗ ΙΟΝΙΚΟΥ ΣΚΙΑΓΡΑΦΙΚΟΥ ΜΕΣΟΥ. ΩΣ ΔΕΙΚΤΕΣ ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΑΝ Η ΜΕΤΡΗΣΗ ΤΗΣ ΚΡΕΑΤΙΝΙΝΗΣ ΟΡΟΥ, ΤΗΣ ΚΡΕΑΤΙΝΙΝΗΣ ΤΩΝ ΠΡΩΤΕΙΝΩΝ, ΤΗΣ Ν-ΑΚΕΤΥΛΟ-Β-D- ΓΛΥΚΟΣΑΜΙΝΙΔΑΣΗΣ ΚΑΙ ΤΗΣ ΤΡΕΧΑΛΑΣΗΣ ΤΩΝ ΟΥΡΩΝ ΚΑΙ ΤΗΣ CLEARANCE ΚΡΕΑΤΙΝΙΝΗΣ ΣΕ 24ΩΡΗ ΒΑΣΗ. ΣΤΑΤΙΣΤΙΚΑ ΣΗΜΑΝΤΙΚΗ ΑΥΞΗΣΗ ΜΕΤΑ ΤΗΝ ΕΓΧΥΣΗ ΚΑΙ ΤΩΝ ΔΥΟ ΣΚΙΑΓΡΑΦΙΚΩΝ ΠΑΡΑΤΗΡΗΘΗΚΕ ΣΤΗΝ ΕΝΖΥΜΟΥΡΙΑ. ΣΤΑΤΙΣΤΙΚΑ ΣΗΜΑΝΤΙΚΗ ΑΥΞΗΣΗ ΜΕΤΑ ΤΗΝ ΕΓΧΥΣΗ ΜΟΝΟ ΤΟΥ NA-MEGLUMINE DIATRIZOATE ΠΑΡΑΤΗΡΗΘΗΚΕ ΣΤΗΝ ΚΡΕΑΤΙΝΟΥΡΙΑ ΚΑΙ ΤΗΝ CLEARANCE ΚΡΕΑΤΙΝΙΝΗΣ ΠΟΥ ΕΙΝΑΙ ΚΑΙ Ο ΠΙΟ ΑΣΦΑΛΗΣ ΔΕΙΚΤΗΣ ΓΙΑ ΤΗΝ ΝΕΦΡΟΤΟΞΙΚΟΤΗΤΑ.
ΑΚΑΜΠΤΑ ΚΑΜΠΥΛΟΓΡΑΜΜΑ ΕΓΚΛΩΒΙΣΜΑΤΑ ΣΕ ΕΠΙΠΕΔΗ ΕΛΑΣΤΙΚΗ ΜΗΤΡΑ ΜΕ ΡΩΓΜΗ ΣΤΗ ΔΙΕΠΙΦΑΝΕΙΑ
Authors: Καττής Μαρίνος
Published: December 2013

ΣΤΗΝ ΕΡΓΑΣΙΑ ΑΥΤΗ ΕΠΙΛΥΕΤΑΙ ΤΟ ΕΛΑΣΤΟΣΤΑΤΙΚΟ ΠΡΟΒΛΗΜΑ ΤΟΥ ΑΚΑΜΠΤΟΥ ΚΑΜΠΥΛΟΓΡΑΜΜΟΥ ΕΓΚΛΩΒΙΣΜΑΤΟΣ ΠΟΥ ΕΙΝΑΙ ΕΝΘΕΤΟ ΣΕ ΜΙΑ ΕΛΑΣΤΙΚΗ ΜΗΤΡΑ ΚΑΙ ΕΤΣΙ ΕΧΕΙ ΜΙΑ ΡΩΓΜΗΣΤΗ ΔΙΕΠΙΦΑΝΕΙΑ. ΕΞΑΓΕΤΑΙ Η ΑΣΥΜΠΤΩΤΙΚΗ ΜΟΡΦΗ ΤΟΥ ΤΑΣΙΚΟΥ ΠΕΔΙΟΥ ΣΤΗΝ ΠΕΡΙΟΧΗ ΤΟΥ ΑΚΡΟΥ ΤΗΣ ΡΩΓΜΗΣ ΚΑΙ ΜΕΛΕΤΑΤΑΙ Η ΣΥΜΠΕΡΙΦΟΡΑ ΤΟΥ ΔΙΦΑΣΙΚΟΥ ΣΥΣΤΗΜΑΤΟΣ ΣΕ ΨΑΘΥΡΗ ΘΡΑΥΣΗ.
Πορείες συνθέσεως ενώσεων με βιολογικό ενδιαφέρον από 2Η-πυραν-3(6Η)-όνες
Authors: Αποστολόπουλος Κωνσταντίνος
Published: December 2013

Η παρούσα διατριβή είναι μια έρευνα με ορισμένους στόχους που πραγματεύεται τη σύνθεση ενώσεων με βιολογικό ενδιαφέρον, αποτελείται δε από τρείς ενότητες. Στην πρώτη γίνεται μια συνοπτική βιβλιογραφική επισκόπηση των θεμάτων που σχετίζονται με το περιεχόμενο της εργασίας. Στη δεύτερη παρουσιάζονται αναλυτικά, τόσο ο σκοπός της διατριβής όσο και οι διεξαχθείσες εργασίες. Στη τρίτη παραθέτονται τα πειραματικά αποτελέσματα και η βιβλιογραφία. Ειδικότερα το πρώτο κεφάλαιο αναφέρεται στις 6-υδροξυ2Η-πυραν-3(6Η)-όνες, στην ονοματολογία, στη στερεοχημεία και στους τρόπους παρασκευής τους. Επίσης στη χρησιμότητα τους ως κοκκιδιοστατικά, μυκητοκτόνα, αντιμικροβιακά αλλά ως ενδιάμεσα για τη σύνθεση σακχάρων, φερομονών, αντιβιοτικών κ.λ.π.. Το δεύτερο κεφάλαιο αναφέρεται στις αντιδράσεις 1,4- προσθήκης που δίνουν οι 2Η-πυραν-3(6Η)-όνες (με διάφορα πυρηνόφιλα) και στη στερεοχημεία των προϊόντων τους. Το τρίτο κεφάλαιο περιλαμβάνει και μία συνοπτική παρουσίαση των ανοσοβιοδιεγερτών και ειδικότερα του μιουραμυλδιπεπτιδίου (MDP). Το τέταρτο κεφάλαιο αναφέρεται στις συμπαθομιμητικές αμίνες, τη σχέση δομής δραστικότητας των και στις κλινικές τους χρήσεις. Επίσης αναφέρεται στους νευροδιαβιβαστές, στο μηχανισμό δράσης τους, στις κατεχολαμίνες και στο γ-αμινο-βουτυρικό οξύ (GABA). Το πέμπτο κεφάλαιο αναφέρεται στους στόχους της διατριβής. Το έκτο κεφάλαιο αναφέρεται στη σύνθεση των 2Η-πυραν-3(6Η)-ονών καθώς και των παραγώγων τους τα οποία χρησιμεύουν στη σύνθεση των ενώσεων-στόχων της διατριβής. Το έβδομο κεφάλαιο αναφέρεται στη σύνθεση των σακχαρυλο-αμινοξέων με 1,4-προσθήκη εστέρων αμινοξέων σε 2Η-πυραν3(6Η)-όνες και στη μελέτη της στερεοχημείας της παραπάνω αντιδράσεως. Τα συμπεράσματα μας συνοψίζονται στα εξής: Όταν ο 6-αλκόξυ-υποκαταστάτης καταλαμβάνει ψευδοαξονική θέση τότε το αμινοξύ εισέρχεται αξονικά η δε αναγωγή του καρβονυλίου δίνει την υδροξυλομάδα σε αξονική θέση. Όταν ο 6-αλκόξυ-υποκαταστάτης καταλαμβάνει ψευδοϊσημερινή θέση τότε το αμινοξύ εισέρχεται ισημερινά και η ανάγωγη δίνει την υδροξυλομάδα επίσης ισημερινή. Επίσης αναφέρεται στην 1,4-προσθήκη πυρηνόφιλων αντιδραστηρίων στις παράγωγες των 2Η-πυραν-3(6Η)-ονών λακτόνες. Τα συμπεράσματα μας συνοψίζονται ως ακολούθως: Μόνο οι μερκαπτάνες να δίνουν σταθερά προϊόντα προσθήκης. Ο εισερχόμενος υποκαταστάτης προσβάλλει, κυρίως το συζυγή της καρβονυλομάδος άνθρακα και προτιμά τον ισημερινό προσανατολισμό. Το όγδοο κεφάλαιο αναφέρεται στη σύνθεση προϊόντων, τα οποία συνδυάζουν στο ίδιο μόριο, τα απαραίτητα χαρακτηριστικά του σκελετού των συμπαθομιμητικών αμινών με το νευροδιαβιβαστή GABA. Τα προϊόντα αυτά πιθανόν να παρουσιάζουν αυξημένη συμπαθομιμητικη ή νευροδιαβιβαστική δραστικότητα. Τέλος στο ένατο κεφάλαιο περιγράφεται μία εύχρηστη και με καλές αποδόσεις μέθοδος για την σύνθεση 5-υποκατεστημένων 2-πυρρολιδινών.
Επίδραση δίαιτας χαμηλής πρωτεΐνης στην πορεία της νεφροπάθειας από αμινονουκλεοσίδιο της πουρομυκίνης σε επίμυς
Authors: Μαρινίδης Γεώργιος
Published: December 2013

Στην παρούσα μελέτη εξετάσθηκαν οι επιδράσεις του πρωτεϊνικού περιεχομένου της τροφής στην πορεία της χρόνιας νεφροπάθειας από αμινονουκλεοσίδιο της πουρομυκίνης (ΝΑΠ). Η ΝΑΠ προκλήθηκε σε αρσενικούς επίμυς Spraque-Dawley με 7 υποδόριες ενέσεις αμινονουκλεοσιδίου (ΑΠ) (20 mg/kg σε διάστημα 10 εβδομάδων), οι οποίοι διαιρέθηκαν σε τρεις ομάδες: με πρωτεϊνικό περιεχόμενο δίαιτας 22.5% (ομάδα 1), 6% (ομάδα 2), και μάρτυρες (3η ομάδα): δίαιτα 22.5%, χωρίς χορήγηση ΑΠ). Οι δύο δίαιτες ήταν ισοθερμιδικές και με το ίδιο περιεχόμενο φωσφόρου και χοληστερόλης. Επίμυες από κάθε ομάδα θυσιάσθηκαν στις 12, στις 18 και στις 24 εβδομάδες. Η πρωτεϊνουρία ήταν σημαντικά μικρότερη στην ομάδα 2 απ' ότι στην ομάδα 1 καθ' όλη την διάρκεια του πειράματος, αλλά η διαφορά έγινε εξαιρετικά έντονη μετά την 12η εβδομάδα. (135+15 έναντι 299+37 mg/ημ., p<0.05, 20±4 έναντι 240±35 mg/ημ. μετά 18 εβδομάδες, p<0.05, και 25±8 έναντι 209±29 mg/ημ. μετά 24 εβδομάδες, p<0.05. Οι τιμές κρεατινίνης ορού ήταν ψηλότερες στην ομάδα 1 απ’ ότι στην 2, αλλά η διαφορά υπήρξε στατιστικά σημαντική μόνο στις 18 εβδομάδες (1.1 ±0.3 έναντι 0.8 ±0.1 mg/dl, p<0.05. Τα επίπεδα χοληστερόλης ορού ήταν σημαντικά ψηλότερα στην ομάδα 1 στις 24 εβδομάδες (286±20 έναντι 148±24 της ομάδας 2 και 101±2 mg/dl των μαρτύρων). Πρώϊμες βλάβες εστιακής τμηματικής σπειραματικής σκλήρυνσης (ΕΤΣΣ) παρατηρήθηκαν με παρόμοια συχνότητα κατά την 12η εβδομάδα και στις δύο ομάδες (16% έναντι 15% και 1.5% των μαρτύρων), αλλά κατά την 18η εβδομάδα διαπιστώθηκε αναστροφή της ΕΤΣΣ στην 2η ομάδα (3% έναντι 14% της ομάδας 1), διαφορά που διατηρήθηκε μέχρι το τέλος του πειράματος (18% (ομάδα 1) έναντι 5% (ομάδα 2). Συμπερασματικά, εφ’ όσον διακοπεί η χορήγηση αμινονουκλεοσιδίου περιορισμός του πρωτεϊνικού περιεχομένου της τροφής για 24 εβδομάδες αναστρέψει τόσο την πρωτεϊνουρία όσο και την πρώϊμη ΕΤΣΣ, που χαρακτηρίζουν την χρόνια ΝΑΠ.
A review of the nomenclature of Gigantopteris
Authors: Doweld Alexander B.
Published: December 2013

The nomenclature of the Upper Palaeozoic fossil genus Gigantopteris is reviewed. The authorship of Gigantopteris is determined to be H.T. Geyler, who published the name as a replacement name for the illegitimate later homonym, Megalopteris A. Schenk.
Technical Note—On Traveling Salesman Games with Asymmetric Costs
Authors: Toriello Alejandro , Uhan Nelson A.
Published: December 2013

We consider cooperative traveling salesman games with nonnegative asymmetric costs satisfying the triangle inequality. We construct a stable cost allocation with budget balance guarantee equal to the Held-Karp integrality gap for the asymmetric traveling salesman problem, using the parsimonious property and a previously unknown connection to linear production games. We also show that our techniques extend to larger classes of network design games. We then provide a simple example showing that our cost allocation does not necessarily achieve the best possible budget balance guarantee, even among cost allocations stable for the game defined by the Held-Karp relaxation, and discuss its implications on future work on traveling salesman games.