bluuebunny/crossref_metadata_2025 huggingface dataset:
The temporal relationship between burnout and prolonged fatigue: a 4‐year prospective cohort study
Authors: Leone Stephanie S. , Huibers Marcus J. H. , Knottnerus J. André , Kant IJmert
Published: July 2010

Burnout and prolonged fatigue have hardly been compared empirically despite their similarities. Knowledge on how these conditions influence each other in time is limited, although this could have implications for (the timing of) intervention. This study examined the temporal relationship between burnout and prolonged fatigue Four‐year prospective follow‐up data from the Maastricht Cohort Study were used for this study. After selection, 11,710 of the 12,140 participants could be included. Measures included the Maslach Burnout Inventory—General Survey and the Checklist Individual Strength. Data were analysed using Cox regression analysis, generalized estimating equation analysis and multinomial regression analysis. Adjustments at baseline were made for burnout or prolonged fatigue score, age, gender, education and absenteeism at baseline. Burnout at baseline was associated with an increased risk of subsequent prolonged fatigue (hazard ratio (HR) 1.33, 95% confidence interval (CI) 1.16–1.53) and prolonged fatigue was associated with an increased risk of subsequent burnout (HR 1.65, 95% CI 1.44–1.89). When burnout and prolonged fatigue influence each other in time, they tend to co‐occur rather than replace each other. Burnout and prolonged fatigue seem to influence each other in the manner of a ‘downward spiral’. Recognizing and correctly identifying fatigue complaints related to burnout and/or prolonged fatigue at an early stage seems important, as early intervention could prevent the conditions from co‐occurring and avert a worsening of outcome. Copyright © 2009 John Wiley & Sons, Ltd.
Yeast Models of Human Mitochondrial Diseases
Authors: Barrientos Antoni
Published: July 2010

The yeast Saccharomyces cerevisiae is an excellent model for gaining insights into the molecular basis of human mitochondrial disorders, particularly those resulting from impaired mitochondrial metabolism. Yeast is a very well characterized system and most of our current knowledge about mitochondrial biogenesis in humans derives from yeast genetics and biochemistry. Systematic yeast genome‐wide approaches have allowed for the identification of human disease genes. In addition, the functional characterization of a large number of yeast gene products resident in mitochondria has been instrumental for the later identification and characterization of their human orthologs. Here I will review the molecular and biochemical characterization of several mitochondrial diseases that have been ascribed to mutations in genes that were first found in yeast to be necessary for the assembly of the mitochondrial respiratory chain. The usefulness of yeast as a model system for human mitochondrial disorders is evaluated.
Impedance of Helicobacter pylori Lipopolysaccharide Interference with Gastric Mucin Synthesis by Peroxisome Proliferator‐Activated Receptor γ Activation Involves Phosphatidylinositol 3‐kinase/ERK Pathway
Authors: Slomiany Bronislaw L. , Slomiany Amalia
Published: July 2010

Peroxisome proliferator‐activated receptor γ (PPARγ) plays a critical role in the regulation of the expression of genes associated with inflammation. In this study, we report that PPARγ activation leading to the impedance of H. pylori lipopolysaccharide (LPS) inhibitory effect on gastric mucin synthesis occurs with the involvement of phosphatidylinositol 3‐kinase (PI3K) and extracellular signal‐regulated kinase (ERK) pathways. Using gastric mucosal cells in culture, we show that activation of PPARγ with a specific synthetic agonist, ciglitazone, prevents in a dose‐dependent fashion (up to 90.2%) the LPS‐induced reduction in mucin synthesis, and the effect is reflected in a marked decrease in the LPS‐induced apoptosis (72.4%), NO generation (80.1%), and the expression of NOS‐2 activity (90%). The impedance by ciglitazone of the LPS‐induced reduction in mucin synthesis was blocked by wortmannin, a specific inhibitor of PI3K and PD98059, an inhibitor of ERK. Both inhibitors, moreover, caused further enhancement in the LPS‐induced NO generation and countered the inhibitory effect of ciglitazone on the LPS‐induced upregulation in NOS‐2. Our findings point to PI3K and ERK as mediators of PPARγ agonist effect leading to the impedance of H. pylori LPS inhibition on gastric mucin synthesis.
Identifying critical junctures in learning in a college course on evolution
Authors: Trowbridge John E. , Wandersee James H.
Published: July 2010

The purpose of this research study was to (a) describe how concept mapping can be used as an integral instructional strategy for teaching a college course on evolution, (b) evaluate the utility of incorporating concept mapping in a college course on evolution, (c) determine whether students' concept maps reveal “critical junctures” in learning as the course unfolds, and (d) assess the impact of concept mapping on students' study practices and on students' understanding of course content. Key findings include: (a) Critical junctures in learning evolution can be identified by monitoring the degree of concordance of superordinate concepts appearing on the class set of concept maps submitted after each of the course lectures; (b) students who made concept maps reported spending an average of 37% more study time on this college biology course than on their previous biology courses; and (c) the use of “seed concepts,” “micromapping,” a standard concept map format, and a standard concept map checklist made the strategy feasible for the instructor to implement and for the student to adopt. A concept map performance index formulas was also developed for this research study in order to assess students' overall mapping performance.
Evolution in secondary school biology textbooks of the PRC, the USA, and the latter stages of the USSR
Authors: Swarts Frederick A. , Roger Anderson O. , Swetz Frank J.
Published: July 2010

The presentations of evolutionary theory in 13 prominent, secondary‐school biology textbooks—3 Chinese, 8 American, and 2 Soviet—were examined using the methods of content analysis. For each book, the amount of text devoted to each of 80 evolutionary topics was assessed. Such word counts were enumerated not only for the main narrative, but also for eight supplemental components (illustrations, marginal information, appendixes, etc.). Pronounced differences in topic emphasis among the 13 textbooks and systematic trends between countries are discussed. The strong emphasis on evolution in the USSR textbooks is impressive, but these textbooks also neglect some major themes, and they devote considerable text to certain concepts of an erroneous or dubious nature. The PRC (People's Republic of China) textbooks fail to introduce a considerable number of topics that are prominent in the other two systems. The eight USA textbooks exhibit great diversity in terms of total evolutionary content, number of themes treated, and which topics are emphasized. Unlike the USSR and PRC textbooks, the USA books position a vast amount of evolutionary content (26.5%‐55.8%) within components outside the main narrative. The evolutionary text of USA editions is dispersed throughout and is presented surprisingly early. Several individual themes that proved particularly revealing are examined, including human evolution, law of recapitulation, evolution and religion, evidences of evolution, punctuated equilibria, and artificial selection.
From down house Landlord to Brazilian high school students: What has happened to evolutionary knowledge on the way?
Authors: Bizzo Nelio Marco Vincenzo
Published: July 2010

Evolution is considered an essential topic that brings to school a broader perspective of natural phenomena and of the nature of science. Most if not all research has shown that the result of the teaching of evolutionary theories is not positive in different parts of the world. Some have attributed the poor understanding shown by students to teaching style or to students' cognitive abilities. This article reports results of interviews and tests carried out with students after they had been taught the topic of evolution. By adopting a sociocultural perspective, before terming students' views “misconceptions,” attention was given to several different ways Charles Darwin's theories have been re‐interpreted by well‐known scholars and offered to the public. I have analyzed the approaches taken by Emanuel Radl (1873‐1942), John C. Greene, Robert Maxwell Young, and Ernst Mayr to assess the diverse ways Darwinism has been conceived. Attention was also given to the presentation of this controversial knowledge to the public in two major popular books written by respected scientists, Huxley and Kettlewell's Darwin and His World (1975) and Richard Dawkins' more recent The Blind Watchmaker (1989). These analyses revealed remarkable differences between what was written in Downe (Kent) a hundred years ago and what was heard at Sao Paulo (Brazil) nowadays. Students show very poor understanding of evolutionary theories. Their conceptions reveal evolution has been primarily related to the human species. Its meaning is understood as similar to progress, growth, multiplication, and improvement. Biological and cultural evolution are not clearly distinguished. Competition is misunderstood as pure violence, sometimes inevitable, and adaptation is considered an individual process that occurs during the organism's life span. Educational change may not depend just on teaching style and students' cognitive abilities. Modification of factual knowledge and epistemological gaps may be the result of a process of social reconceptualization of knowledge offered to students.
Counterpoint: Belief, understanding, and the teaching of evolution
Authors: Smith Mike U.
Published: July 2010

If we are to be successful in teaching evolution, we must take into account our students' worldviews as well as their individual understandings and misconceptions. This article makes several recommendations for how this might be accomplished in a way that respects individual student backgrounds and beliefs but is also scientifically appropriate. It is important (a) to know our students—their cultures, personal histories, cognitive abilities, religious beliefs, scientific misconceptions, and so forth; (b) to take this opportunity to teach about the nature of science and its distinctions from nonscience; (c) to address directly the likely cultural/religious concerns with evolution and to do so early on so as to break down the barriers that keep many students from hearing what you say; and (d) to present evolution appropriately as conflicting with none but the most fundamentalist religious tenets that demand a literal translation of the Bible. I have also argued that the approach advocated by Cobern in the previous article that focuses on belief in evolution is ill‐advised on several grounds, principally because students may understand the term belief as synonymous with faith, opinion, or conviction and not as equivalent to the scientist's meaning of the term acceptance.
Establishment of an Intraoperative Staging System (iStage) by Improving UICC TNM Classification System for Papillary Thyroid Carcinoma
Authors: Ito Yasuhiro , Ichihara Kiyoshi , Masuoka Hiroo , Fukushima Mitsuhiro , Inoue Hiroyuki , Kihara Minoru , Tomoda Chisato , Higashiyama Takuya , Takamura Yuuki , Kobayashi Kaoru , Miya Akihiro , Miyauchi Akira
Published: July 2010

Background

Papillary thyroid carcinoma generally has an indolent nature, but cases demonstrating certain features are progressive. UICC TNM classification is the most widely adopted system to evaluate the biological behavior of this carcinoma, but it is doubtful whether this system that evaluates only the preoperative findings can appropriately reflect patient prognosis. In this study, we established a new staging system (iStage) based on not only preoperative but also intraoperative findings.

Methods

We investigated the prognoses of 5,911 patients with papillary carcinoma without distant metastasis at diagnosis who underwent initial surgery between January 1987 and January 2005 and compared the utility of iStage with that of conventional classification systems, such as UICC Stage, MACIS score (>7 and ≤7), AMES, and CIH classification.

Results

Disease‐free survival (DFS) and cause‐specific survival (CSS) of patients with stage IVA were better than those of high‐risk patients on other systems, and CSS of stage III patients did not differ from stage IVA patients. We established iStage by improving the original UICC stage. We set cutoff age to 55 years, instead of 45. Patients showing significant, not minimal, extrathyroid extension on intraoperative findings underwent T upgrading: tumor size 2 cm or smaller to T3 and larger than 2 cm to T4a. N classification was revised based on the size of node metastasis and extranodal tumor extension: N0, no preoperatively detected regional node metastasis; N1, preoperatively detected regional node metastasis measuring 3 cm or less and without extranodal tumor extension on intraoperative findings; N2, regional node metastasis >3 cm or having extranodal tumor extension on intraoperative examination. Five‐year and 10‐year DFS and CSS of iStage IVA patients were worse than high‐risk patients on other classification systems, and iStage III patients showed a worse DFS, but not CSS, than iStage I or II patients.

Conclusions

We established a new classification system, iStage, based not only on preoperative but also on intraoperative findings, which has high utility. Appropriate intraoperative evaluation is mandatory to grade biological characteristics, including prognosis, of papillary carcinoma.
Integration of Genomics into Rice Breeding
Authors: Fukuoka Shuichi , Ebana Kaworu , Yamamoto Toshio , Yano Masahiro
Published: July 2010

One of the major challenges in genetics has been to identify the nucleotide polymorphisms responsible for phenotypic variation. Through intensive analysis, several major quantitative trait loci (QTLs) for agronomic traits in rice have been identified and the underlying candidate genes have been delimited. Advanced mapping populations, including chromosome segment substitution lines, have enhanced the power of genetic analysis to detect QTL alleles, even those with minor effects. Recent examples of marker-assisted selection have proven the potential of this strategy for crop improvement. The genome-wide discovery of single nucleotide polymorphisms (SNPs), even among closely related cultivars, has enhanced the power of allele mining in a wide range of rice breeding materials. An array-based SNP genotyping system can be used to visualize pedigree haplotypes in breeding materials, including landraces and modern cultivars. All of these technologies are accelerating the genetic dissection of complex agronomic traits and further improvement of rice.
Bowel Preparation Suitable for Same-day Computed Tomography Colonography and Colonoscopy
Authors: Eddy Maggie , Stevenson Giles , Mathieson John , Behrens Carola , Eddy Richard
Published: July 2010

Purpose

This study was designed to evaluate whether a bowel preparation used for computed tomography (CT) colonography could also be suitable for same-day colonoscopy regardless of which test was done first.

Method

Six different endoscopists working at 3 separate hospitals evaluated 75 patients who underwent colonoscopy after receiving a bowel preparation that contained contrast material used to tag fecal and fluid material to facilitate CT colonography. This bowel preparation has been used in more than 1500 CT colonography studies. Evaluation included assessment of whether the colon was clean and dry, and whether the contrast material caused any impairment of visualization or clogging of the endoscopes. Some of the patients had first undergone CT colonography followed by same-day colonoscopy, whereas other patients had colonoscopy as their initial test.

Results

Although the contrast material was sometimes perceptible, the volumes were very small, and caused no impairment of mucosal visualization and no clogging of the endoscopes. The bowel preparation was well tolerated. Same-day CT colonography and colonoscopy with fecal tagging was technically possible.

Conclusion

A simple, fairly low cost 1-day bowel preparation with fluid and fecal tagging is suitable for CT colonography and colonoscopy done the same day in either order. However, the preferences of individual endoscopists and difficulties with making oral contrast agents readily available are challenges to widespread adoption of a common bowel preparation regimen.
Origin of the pKa shift of the catalytic lysine in acetoacetate decarboxylase
Authors: Ishikita Hiroshi
Published: July 2010

The pK
a value of Lys115, the catalytic residue in acetoacetate decarboxylate, was calculated using atomic coordinates of the X‐ray crystal structure with consideration of the protonation states of all titratable sites in the protein. The calculated pK
a value of Lys115 (pK
a(Lys115)) was unusually low (≈6) in agreement with the experimentally measured value. Although charged residues impact pK
a(Lys115) considerably in the native protein, the significant pK
a(Lys115) downshift in the protein with respect to aqueous solution was mainly due to loss of the solvation energy in the catalytic active site relative to bulk water.
Mutational deglycosylation of the Fc portion of immunoglobulin G causes O‐sulfation of tyrosine adjacently preceding the originally glycosylated site
Authors: Masuda Katsuyoshi , Yamaguchi Yoshiki , Takahashi Noriko , Jefferis Royston , Kato Koichi
Published: July 2010

Mutagenesis directed to a specific glycosylation site has been widely used to examine biological roles of individual glycans. However, occurrence of any post‐translational modification on such deglycosylated mutants has not yet been well characterized. Here we performed mass spectrometric analyses of the Fc fragment of an unglycosylated mutant of mouse immunoglobulin G2b, whose conserved N‐glycosylation site, i.e. Asn297, was substituted with alanine. We found that a major part of this mutant is sulfated at Tyr296, which adjacently precedes the originally glycosylated site. Our findings demonstrate that mutational deglycosylation can induce an unexpected post‐translational modification in the protein.
NLS‐mediated NPC functions of the nucleoporin Pom121
Authors: Yavuz Sevil , Santarella-Mellwig Rachel , Koch Birgit , Jaedicke Andreas , Mattaj Iain W. , Antonin Wolfram
Published: July 2010

MINT‐7951306, MINT‐7951362: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:Q7ZWL0), nup160 (uniprotkb:P83722), nup93 (uniprotkb:Q7ZX96), Importin beta (uniprotkb:P52297) and nup62 (uniprotkb:Q91349) by pull down (MI:0096)
Tropomyosin‐binding properties of the CHASM protein are dependent upon its calponin homology domain
Authors: Ulke-Lemée Annegret , Ishida Hiroaki , Borman Meredith A. , Valderrama Alexandra , Vogel Hans J. , MacDonald Justin A.
Published: July 2010

MINT‐7966090: CHASM (uniprotkb:Q99LM3) binds (MI:0407) to Tropomyosin alpha (uniprotkb:P04268) by pull down (MI:0096)
Effects of accuracy motivation and need to evaluate on mode of attitude formation and attitude–behavior consistency
Authors: Cronley Maria L. , Mantel Susan Powell , Kardes Frank R.
Published: July 2010

This study investigates the effects of accuracy motivation and need to evaluate on online vs. memory‐based attitude formation and attitude–behavior consistency. Results show that online attitude formation is more likely when accuracy motivation or the need to evaluate is high. However, cognitive load disrupts online attitude formation even when accuracy motivation is high. Additionally, attitude relevance increases the likelihood of online attitude formation, but attitude accessibility does not. Furthermore, online (vs. memory‐based) attitudes are more predictive of subsequent non‐hypothetical choice.
Comparison of purple carrot juice and β-carotene in a high-carbohydrate, high-fat diet-fed rat model of the metabolic syndrome
Authors: Poudyal Hemant , Panchal Sunil , Brown Lindsay
Published: July 2010

Anthocyanins, phenolic acids and carotenoids are the predominant phytochemicals present in purple carrots. These phytochemicals could be useful in treatment of the metabolic syndrome since anthocyanins improve dyslipidaemia, glucose tolerance, hypertension and insulin resistance; the phenolic acids may also protect against CVD and β-carotene may protect against oxidative processes. In the present study, we have compared the ability of purple carrot juice and β-carotene to reverse the structural and functional changes in rats fed a high-carbohydrate, high-fat diet as a model of the metabolic syndrome induced by diet. Cardiac structure and function were defined by histology, echocardiography and in isolated hearts and blood vessels; liver structure and function, oxidative stress and inflammation were defined by histology and plasma markers. High-carbohydrate, high-fat diet-fed rats developed hypertension, cardiac fibrosis, increased cardiac stiffness, endothelial dysfunction, impaired glucose tolerance, increased abdominal fat deposition, altered plasma lipid profile, liver fibrosis and increased plasma liver enzymes together with increased plasma markers of oxidative stress and inflammation as well as increased inflammatory cell infiltration. Purple carrot juice attenuated or reversed all changes while β-carotene did not reduce oxidative stress, cardiac stiffness or hepatic fat deposition. As the juice itself contained low concentrations of carotenoids, it is likely that the anthocyanins are responsible for the antioxidant and anti-inflammatory properties of purple carrot juice to improve glucose tolerance as well as cardiovascular and hepatic structure and function.
Estimation of percentage body fat in 6- to 13-year-old children by skinfold thickness, body mass index and waist circumference
Authors: Kriemler Susi , Puder Jardena , Zahner Lukas , Roth Ralf , Meyer Ursina , Bedogni Giorgio
Published: July 2010

We evaluated the accuracy of skinfold thicknesses, BMI and waist circumference for the prediction of percentage body fat (PBF) in a representative sample of 372 Swiss children aged 6–13 years. PBF was measured using dual-energy X-ray absorptiometry. On the basis of a preliminary bootstrap selection of predictors, seven regression models were evaluated. All models included sex, age and pubertal stage plus one of the following predictors: (1) log-transformed triceps skinfold (logTSF); (2) logTSF and waist circumference; (3) log-transformed sum of triceps and subscapular skinfolds (logSF2); (4) log-transformed sum of triceps, biceps, subscapular and supra-iliac skinfolds (logSF4); (5) BMI; (6) waist circumference; (7) BMI and waist circumference. The adjusted determination coefficient (R _{adj}^{2} ) and the root mean squared error (RMSE; kg) were calculated for each model. LogSF4 (R _{adj}^{2} 0·85; RMSE 2·35) and logSF2 (R _{adj}^{2} 0·82; RMSE 2·54) were similarly accurate at predicting PBF and superior to logTSF (R _{adj}^{2} 0·75; RMSE 3·02), logTSF combined with waist circumference (R _{adj}^{2} 0·78; RMSE 2·85), BMI (R _{adj}^{2} 0·62; RMSE 3·73), waist circumference (R _{adj}^{2} 0·58; RMSE 3·89), and BMI combined with waist circumference (R _{adj}^{2} 0·63; RMSE 3·66) (P < 0·001 for all values of R _{adj}^{2} ). The finding that logSF4 was only modestly superior to logSF2 and that logTSF was better than BMI and waist circumference at predicting PBF has important implications for paediatric epidemiological studies aimed at disentangling the effect of body fat on health outcomes.
THE CHANGING SEX RATIOS AT BIRTH DURING THE CIVIL WAR IN TAJIKISTAN: 1992–1997
Authors: HOHMANN SOPHIE , ROCHE SOPHIE , GARENNE MICHEL
Published: July 2010

Sex ratios at birth are known to change during wars or shortly after. This study investigated changes in sex ratios during the civil war that occurred in Tajikistan after the dismantling of the Soviet Union. This civil war was particularly bloody and long lasting, and had many demographic consequences. According to vital registration data, some 27,000 persons died in excess of previous trends during the civil war period (1992–1997), and total mortality was sometimes estimated to be three times higher by independent observers. Birth rates dropped markedly during the war, and sex ratios at birth increased significantly from 104.6 before the war to 106.9 during the war, to return to baseline values afterwards. The change in sex ratio is investigated according to demographic evidence (migration, delayed marriage, spouse separation), substantiated with qualitative evidence (difficulties with food supply), and compared with patterns found in Europe during World War II, as well as with recent wars in the Middle East.
Use of flow cytometry to separateLeucocytozoon caulleryigametocytes from avian blood
Authors: OMORI SUMIE , SATO YUKITA , TODA HIDEAKI , SASAKI KAZUE , ISOBE TAKASHI , NAKANISHI TERUYUKI , MURATA KOICHI , YUKAWA MASAYOSHI
Published: July 2010

The highly pathogenic avian protozoanLeucocytozoon caulleryiinfects host chicken cells, and interference by the host genome results in difficulty in obtaining protozoal DNA for genetic analysis. We used flow cytometry analysis to separate expelledL. caulleryigametocytes from infected chicken blood and to analyse cell populations and sorting by FACS efficiency. Infected blood cells stained with SYTO-24 showed a specific area on 2-dimensional scattergrams compared to uninfected blood. The specific area was sorted, and approximately 85% of the sorted cells were identified asL. caulleryigametocytes by microscopic observation. DNA was also extracted from the sorted fraction, and a clear increase in polymerase chain reaction (PCR) amplification of protozoal DNA was observed compared to infected blood without sorting. Host-derived DNA was also detected by PCR; however, its amplification was decreased compared to that in unsorted infected blood. This is the first report of the separation ofL. caulleryigametocytes from infected host blood using flow cytometry. This method may be applied to further genetic analyses such as studies of the dynamics of stage-specificL. caulleryigene expression.
Scrutinizing design educators' perceptions of the design process
Authors: Strickfaden Megan , Heylighen Ann
Published: July 2010

When developing a better understanding of the design process there are several possible approaches to choose from. Many studies are based on novice designers (e.g., students) or designers of relatively modest talents. By contrast, some studies have queried designers who are considered to have outstanding and exceptional ability in order to gain an understanding of design at the highest level that it is practiced. The study reported here adopts yet another approach by exploring how design processes are perceived by design educators. The approach is motivated by the observation that teaching design requires consciously distilling the essence of the design process for the students, observing students during their design process and guiding them through the process. As a result, design teachers tend to develop a more articulate view of design processes than most other designers. Nineteen design teachers are interviewed using general topics as discussion points. Such an approach is invaluable when exploring more abstract research questions such as the notion of design processes. This approach differs from more controlled approaches (e.g., protocol analysis) in that it accepts that the data obtained are partially driven by negotiation between the researchers and the participants, and that the discussions are largely stories or narratives about design and designing. The resulting data illustrate that design processes are interpreted, articulated, and understood in a variety of ways by different teachers. These data and subsequent results tell us in rich detail about designing and design teaching, and as a result extend our understanding of the design process.
Matching pedagogical intent with engineering design process models for precollege education
Authors: Tate Derrick , Chandler John , Fontenot A. Dean , Talkmitt Susan
Published: July 2010

Public perception of engineering recognizes its importance to national and international competitiveness, economy, quality of life, security, and other fundamental areas of impact; but uncertainty about engineering among the general public remains. Federal funding trends for education underscore many of the concerns regarding teaching and learning in science, technology, engineering, and mathematics subjects in primary through grade 12 (P-12) education. Conflicting perspectives on the essential attributes that comprise the engineering design process results in a lack of coherent criteria against which teachers and administrators can measure the validity of a resource, or assess its strengths and weaknesses, or grasp incongruities among competing process models. The literature suggests two basic approaches for representing engineering design: a phase-based, life cycle-oriented approach; and an activity-based, cognitive approach. Although these approaches serve various teaching and functional goals in undergraduate and graduate engineering education, as well as in practice, they tend to exacerbate the gaps in P-12 engineering efforts, where appropriate learning objectives that connect meaningfully to engineering are poorly articulated or understood. In this article, we examine some fundamental problems that must be resolved if preengineering is to enter the P-12 curriculum with meaningful standards and is to be connected through learning outcomes, shared understanding of engineering design, and other vestiges to vertically link P-12 engineering with higher education and the practice of engineering. We also examine historical aspects, various pedagogies, and current issues pertaining to undergraduate and graduate engineering programs. As a case study, we hope to shed light on various kinds of interventions and outreach efforts to inform these efforts or at least provide some insight into major factors that shape and define the environment and cultures of the two institutions (including epistemic perspectives, institutional objectives, and political constraints) that are very different and can compromise collaborative efforts between the institutions of P-12 and higher education.
Statistical behavior of the topside electron density as determined from DMSP observations: A probabilistic climatology
Authors: Garner T. W. , Taylor B. T. , Gaussiran T. L. , Coley W. R. , Hairston M. R. , Rich F. J.
Published: July 2010

The Defense Meteorological Satellite Program (DMSP) has flown spacecraft with ionospheric payloads since 1987. Over this period, DMSP has collected over two hundred million electron density measurements. This paper presents a statistical analysis of the DMSP topside electron density measurements from 1995 to 2005 with additional data from 1992. Nearly 140 million quality‐checked data points are binned by solar activity, magnetic latitude, season, and solar zenith angle or magnetic local time. When binned, the data usually obey a three‐parameter lognormal distribution. These parameters represent the density floor (the minimum possible density), the median density, and the variability in the densities. In general, the density floor, the median density, and the variability increase with solar activity and peak near the magnetic equator. Away from the equator, these parameters are higher during local summer and for lower solar zenith angles. However, the median density and the variability near the magnetic equator are greater in the dusk sector where the prereversal enhancement pushes F region plasma to higher altitudes. In addition, all three parameters show a marked asymmetry between the northern and southern hemispheres. A probabilistic climatology model is created by modeling these parameters and using the lognormal probability distribution function. This new model provides an occurrence frequency for different densities given the F10.7 solar radio flux, magnetic latitude, day of year, and either solar zenith angle or magnetic local time.
Near‐ultraviolet and blue spectral observations of sprites in the 320–460 nm region: N2 (2PG) emissions
Authors: Heavner M. J. , Morrill J. S. , Siefring C. , Sentman D. D. , Moudry D. R. , Wescott E. M. , Bucsela E. J.
Published: July 2010

A near‐ultraviolet (NUV) spectrograph (320–460 nm) was flown on the EXL98 aircraft sprite observation campaign during July 1998. In this wavelength range video rate (60 fields/sec) spectrographic observations found the NUV and blue emissions to be predominantly N2 (2PG). The negligible level of N2+ (1NG) present in the spectrum is confirmed by observations of a co‐aligned, narrowly filtered 427.8 nm imager and is in agreement with previous ground‐based filtered photometer observations. The synthetic spectral fit to the observations indicates a characteristic energy of ∼1.8 eV, in agreement with our other NUV observations.
Geodetic evidence for en echelon dike emplacement and concurrent slow slip during the June 2007 intrusion and eruption at Kīlauea volcano, Hawaii
Authors: Montgomery‐Brown E. K. , Sinnett D. K. , Poland M. , Segall P. , Orr T. , Zebker H. , Miklius A.
Published: July 2010

A series of complex events at Kīlauea Volcano, Hawaii, 17 June to 19 June 2007, began with an intrusion in the upper east rift zone (ERZ) and culminated with a small eruption (1500 m3). Surface deformation due to the intrusion was recorded in unprecedented detail by Global Positioning System (GPS) and tilt networks as well as interferometric synthetic aperture radar (InSAR) data acquired by the ENVISAT and ALOS satellites. A joint nonlinear inversion of GPS, tilt, and InSAR data yields a deflationary source beneath the summit caldera and an ENE‐striking uniform‐opening dislocation with ∼2 m opening, a dip of ∼80° to the south, and extending from the surface to ∼2 km depth. This simple model reasonably fits the overall pattern of deformation but significantly misfits data near the western end of an inferred dike‐like source. Three more complex dike models are tested that allow for distributed opening including (1) a dike that follows the surface trace of the active rift zone, (2) a dike that follows the symmetry axis of InSAR deformation, and (3) two en echelon dike segments beneath mapped surface cracks and newly formed steaming areas. The en echelon dike model best fits near‐field GPS and tilt data. Maximum opening of 2.4 m occurred on the eastern segment beneath the eruptive vent. Although this model represents the best fit to the ERZ data, it still fails to explain data from a coastal tiltmeter and GPS sites on Kīlauea's southwestern flank. The southwest flank GPS sites and the coastal tiltmeter exhibit deformation consistent with observations of previous slow slip events beneath Kīlauea's south flank, but inconsistent with observations of previous intrusions. Slow slip events at Kīlauea and elsewhere are thought to occur in a transition zone between locked and stably sliding zones of a fault. An inversion including slip on a basal decollement improves fit to these data and suggests a maximum of ∼15 cm of seaward fault motion, comparable to previous slow‐slip events.
Recent loss of floating ice and the consequent sea level contribution
Authors: Shepherd Andrew , Wingham Duncan , Wallis David , Giles Katharine , Laxon Seymour , Sundal Aud Venke
Published: July 2010

We combine new and published satellite observations and the results of a coupled ice‐ocean model to provide the first estimate of changes in the quantity of ice floating in the global oceans and the consequent sea level contribution. Rapid losses of Arctic sea ice and small Antarctic ice shelves are partially offset by thickening of Antarctic sea ice and large Antarctic ice shelves. Altogether, 746 ± 127 km3 yr−1 of floating ice was lost between 1994 and 2004, a value that exceeds considerably the reduction in grounded ice over the same period. Although the losses are equivalent to a small (49 ± 8 μm yr−1) rise in mean sea level, there may be large regional variations in the degree of ocean freshening and mixing. Ice shelves at the Antarctic Peninsula and in the Amundsen Sea, for example, have lost 481 ± 38 km3 yr−1.
Calpain is involved in C-terminal truncation of human aggrecan
Authors: Struglics André , Hansson Maria
Published: July 2010

Mature aggrecan is generally C-terminally truncated at several sites in the CS (chondroitin sulfate) region. Aggrecanases and MMPs (matrix metalloproteinases) have been suggested to be responsible for this digestion. To identify whether calpain, a common intracellular protease, has a specific role in the proteolysis of aggrecan we developed neoepitope antibodies (anti-PGVA, anti-GDLS and anti-EDLS) against calpain cleavage sites and used Western blot analysis to identify calpain-generated fragments in normal and OA (osteoarthritis) knee cartilage and SF (synovial fluid) samples. Our results showed that human aggrecan contains six calpain cleavage sites: one in the IGD (interglobular domain), one in the KS (keratan sulfate) region, two in the CS1 and two in the CS2 region. Kinetic studies of calpain proteolysis against aggrecan showed that the aggrecan molecule was cleaved in a specific order where cuts in CS1 was the most preferred and cuts in KS region was the second most preferred cleavage. OA and normal cartilage contained low amounts of a calpain-generated G1–PGVA fragment (0.5–2%) compared with aggrecanase-generated G1–TEGE (71–76%) and MMP-generated G1–IPEN (23–29%) fragments. Significant amounts of calpain-generated GDLS and EDLS fragments were found in OA and normal cartilage, and a ARGS–EDLS fragment was detected in arthritic SF samples. The results of the present study indicate that calpains are involved in the C-terminal truncation of aggrecan and might have a minor role in arthritic diseases.
Performance of multireference and equation-of-motion coupled-cluster methods for potential energy surfaces of low-lying excited states: Symmetric and asymmetric dissociation of water
Authors: Li Xiangzhu , Paldus Josef
Published: July 2010

Multireference (MR), general-model-space (GMS), state-universal (SU) coupled-cluster (CC) method that considers singly (S) and doubly (D) excited cluster amplitudes relative to the reference configurations spanning the model space (GMS SU CCSD), as well as its externally corrected (ec) version (N,M)-CCSD that employs N-reference MR CISD as an external source of higher-than-pair cluster amplitudes in a M-reference GMS CCSD, are employed to investigate low-lying states of the water molecule. The emphasis is on a generation of several low lying states belonging to the same symmetry species. Cuts of the potential energy surface (PES) corresponding to the breaking of a single OH bond and leading to the OH+H fragments, as well as the simultaneous breaking of both bonds into the O+2H are considered. Relying on a simple ab initio model that enables a comparison with the exact full configuration interaction energies, the performance of the GMS-based methods is assessed in the whole relevant range of internuclear separations. It is shown that the ec (N,M)-CCSD version provides best results for both the singlet and the triplet states considered. The same cuts of the PES are then explored using a realistic aug-cc-pVTZ basis set. For triplets, the use of high-spin (MS=1) references is to be preferred.
Generation of charged nanoparticles and their deposition during the synthesis of silicon thin films by chemical vapor deposition
Authors: Kim Chan-Soo , Youn Woong-Kyu , Hwang Nong-Moon
Published: July 2010

Generation of charged nanoparticles in the gas phase has been frequently reported in many chemical vapor deposition (CVD) processes. In an effort to confirm whether charged nanoparticles are generated during the synthesis of silicon films by CVD, a differential mobility analyzer combined with a Faraday cup electrometer was connected to an atmospheric-pressure CVD reactor under typical conditions for silicon film growth. The size distribution of positively and negatively charged nanoparticles abundantly generated in the gas phase could be measured. An electric bias applied to the substrate holder affects the growth rate, the crystallinity and the morphology of the deposited films. The bias effect indicated that charged nanoparticles were actively involved in the film growth.
Higher energy electronic transitions of HC2n+1H+ (n=2–7) and HC2n+1H (n=4–7) in neon matrices
Authors: Fulara Jan , Nagy Adam , Garkusha Iryna , Maier John P.
Published: July 2010

Electronic absorption spectra of linear HC2n+1H+ (n=2–7) were recorded in 6 K neon matrices following their mass-selective deposition. Four new electronic band systems are identified; the strongest Ẽ Π2g/u←X̃ Π2u/g lies in the UV and the second most intense C̃ Π2g/u←X̃ Π2u/g is located in the visible range. The known Ã Π2g/u←X̃ Π2u/g absorption is an order of magnitude weaker than C̃ Π2g/u←X̃ Π2u/g. Transitions to the B̃ and D̃ states are also discussed. The wavelengths of the HC2n+1H+ (n=2–7) electronic systems obey a linear relation as a function of the size of the cations, similar to other carbon chains. The B̃ Σu−3←X̃ Σg−3 transition in the UV of neutral HC2n+1H (n=4–7) has also been identified upon photobleaching of the cations trapped in the matrices.
A tractable and accurate electronic structure method for static correlations: The perfect hextuples model
Authors: Parkhill John A. , Head-Gordon Martin
Published: July 2010

We present the next stage in a hierarchy of local approximations to complete active space self-consistent field (CASSCF) model in an active space of one active orbital per active electron based on the valence orbital-optimized coupled-cluster (VOO-CC) formalism. Following the perfect pairing (PP) model, which is exact for a single electron pair and extensive, and the perfect quadruples (PQ) model, which is exact for two pairs, we introduce the perfect hextuples (PH) model, which is exact for three pairs. PH is an approximation to the VOO-CC method truncated at hextuples containing all correlations between three electron pairs. While VOO-CCDTQ56 requires computational effort scaling with the 14th power of molecular size, PH requires only sixth power effort. Our implementation also introduces some techniques which reduce the scaling to fifth order and has been applied to active spaces roughly twice the size of the CASSCF limit without any symmetry. Because PH explicitly correlates up to six electrons at a time, it can faithfully model the static correlations of molecules with up to triple bonds in a size-consistent fashion and for organic reactions usually reproduces CASSCF with chemical accuracy. The convergence of the PP, PQ, and PH hierarchy is demonstrated on a variety of examples including symmetry breaking in benzene, the Cope rearrangement, the Bergman reaction, and the dissociation of fluorine.
Enhancement of the water proton relaxivity by trapping Gd3+ complexes in nanovesicles
Authors: Fries Pascal H. , Belorizky Elie
Published: July 2010

We present a theoretical model for calculating the relaxivity of the water protons due to Gd3+ complexes trapped inside nanovesicles, which are permeable to water. The formalism is applied to the characterization of apoferritin systems [S. Aime et al., Angew. Chem., Int. Ed. 41, 1017 (2002); O. Vasalatiy et al., Contrast Media Mol. Imaging 1, 10 (2006)]. The very high relaxivity due to these systems is attributed to an increase of the local viscosity of the aqueous solution inside the vesicles and to an outer-sphere mechanism which largely dominates the inner-sphere contribution. We discuss how to tailor the dynamic parameters of the trapped complexes in order to optimize the relaxivity. More generally, the potential of relaxivity studies for investigating the local dynamics and residence time of exchangeable molecules in nanovesicles is pointed out.
Design and construction of pulsed neutron diagnostic system for plasma focus device (SBUPF1)
Authors: Moghadam Sahar Rajabi , Davani Fereydoon Abbasi
Published: July 2010

In this paper, two designs of pulsed neutron counter structure are introduced. To increase the activation counter efficiency, BC-400 plastic scintillator plates along with silver foils are utilized. Rectangular cubic and cylindrical geometries for activation counter cell are modeled using MCNP4C code. Eventually, an optimum length of 14 cm is calculated for the detector cell and optimum numbers of 20 silver foils for rectangular cubic geometry and ten foils for cylindrical geometry have been acquired. Due to the high cost of cutting, polishing of plastics, and etc., the rectangular cubic design is found to be more economical than the other design. In order to examine the functionality and ensure the detector output and corresponding designing, neutron yield of a 2.48 kJ plasma focus device (SBUPF1) in 8 mbar pressure with removal source method for calibration was measured (3.71±0.32)×107 neutrons per shot.
An open-walled ionization chamber appropriate to tritium monitoring for glovebox
Authors: Chen Zhilin , Chang Ruiming , Mu Long , Song Guoyang , Wang Heyi , Wu Guanyin , Wei Xiye
Published: July 2010

An open-walled ionization chamber is developed to monitor the tritium concentration in gloveboxes in tritium processing systems. Two open walls are used to replace the sealed wall in common ionization chambers, through which the tritium gas can diffuse into the chamber without the aid of pumps and pipelines. Some basic properties of the chamber are examined to evaluate its performance. Results turn out that an open-walled chamber of 1 l in volume shows a considerably flat plateau over 700 V for a range of tritium concentration. The chamber also gives a good linear response to gamma fields over 4 decades under a pressure condition of 1 atm. The pressure dependence characteristics show that the ionization current is only sensitive at low pressures. The pressure influence becomes weaker as the pressure increases mainly due to the decrease in the mean free path of β particles produced by tritium decay. The minimum detection limit of the chamber is 3.7×105 Bq/m3.
Enhancement of room temperature ferromagnetism in N-doped TiO2−x rutile: Correlation with the local electronic properties
Authors: Drera G. , Mozzati M. C. , Galinetto P. , Diaz-Fernandez Y. , Malavasi L. , Bondino F. , Malvestuto M. , Sangaletti L.
Published: July 2010

The magnetic and electronic properties of ferromagnetic undoped and N-doped TiO2−x rutile have been probed by soft x-ray spectroscopies. Upon N doping, a fivefold enhancement of the saturation magnetization is observed. Apparently, this enhancement is not related to an increase in oxygen vacancies, rather to additional in-gap states, arising from the replacement of O with N atoms in the rutile structure that can provide more favorable conditions for the onset of ferromagnetic ordering.
Polymer translocation through pores with complex geometries
Authors: Mohan Aruna , Kolomeisky Anatoly B. , Pasquali Matteo
Published: July 2010

We propose a method for the theoretical investigation of polymer translocation through composite pore structures possessing arbitrarily specified geometries. The proposed method accounts for possible reverse chain motions at the interface between the constituent parts of a composite pore. As an illustration of our method, we study polymer translocation between two spherical compartments connected by a cylindrical pore and by a composite pore consisting of two connected cylinders of different diameters, which is structurally similar to the α-hemolysin membrane channel. We demonstrate that reverse chain motions between the pore constituents may contribute significantly to the total translocation time. Our results further establish that translocation through a two-cylinder composite pore is faster when the chain is introduced into the pore on the cis (wide) side of the channel rather than the trans (narrow) side.