Consideration of learning orientations as an application of achievement goals in evaluating life science majors in introductory physics

NASA Astrophysics Data System (ADS)

Mason, Andrew J.; Bertram, Charles A.

2018-06-01

When considering performing an Introductory Physics for Life Sciences course transformation for one's own institution, life science majors' achievement goals are a necessary consideration to ensure the pedagogical transformation will be effective. However, achievement goals are rarely an explicit consideration in physics education research topics such as metacognition. We investigate a sample population of 218 students in a first-semester introductory algebra-based physics course, drawn from 14 laboratory sections within six semesters of course sections, to determine the influence of achievement goals on life science majors' attitudes towards physics. Learning orientations that, respectively, pertain to mastery goals and performance goals, in addition to a learning orientation that does not report a performance goal, were recorded from students in the specific context of learning a problem-solving framework during an in-class exercise. Students' learning orientations, defined within the context of students' self-reported statements in the specific context of a problem-solving-related research-based course implementation, are compared to pre-post results on physics problem-solving items in a well-established attitudinal survey instrument, in order to establish the categories' validity. In addition, mastery-related and performance-related orientations appear to extend to overall pre-post attitudinal shifts, but not to force and motion concepts or to overall course grade, within the scope of an introductory physics course. There also appears to be differentiation regarding overall course performance within health science majors, but not within biology majors, in terms of learning orientations; however, health science majors generally appear to fare less well on all measurements in the study than do biology majors, regardless of learning orientations.

Using Computer Animation and Illustration Activities to Improve High School Students' Achievement in Molecular Genetics

ERIC Educational Resources Information Center

Marbach-Ad, Gili; Rotbain, Yosi; Stavy, Ruth

2008-01-01

Our main goal in this study was to determine whether the use of computer animation and illustration activities in high school can contribute to student achievement in molecular genetics. Three comparable groups of eleventh- and twelfth-grade students participated: the control group (116 students) was taught in the traditional lecture format,…

The Effective Practices and Beliefs of School Principals in High Achieving Hispanic Majority Mid-Level Schools

ERIC Educational Resources Information Center

Briseno, Johnny

2010-01-01

This qualitative phenomenological research study used narrative inquiry to investigate the effective practices and beliefs of 10 Texas principals in high achieving majority Hispanic mid-level schools. Participant interviews were analyzed using the Creswell (2007) six step method for analyzing phenomenological studies. Findings from this study…

A Unique Large-Scale Undergraduate Research Experience in Molecular Systems Biology for Non-Mathematics Majors

ERIC Educational Resources Information Center

Kappler, Ulrike; Rowland, Susan L.; Pedwell, Rhianna K.

2017-01-01

Systems biology is frequently taught with an emphasis on mathematical modeling approaches. This focus effectively excludes most biology, biochemistry, and molecular biology students, who are not mathematics majors. The mathematical focus can also present a misleading picture of systems biology, which is a multi-disciplinary pursuit requiring…

Exploring the undergraduate experience of Latina students in Science, Technology, Engineering, and Mathematics (STEM) majors: Motivators and strategies for achieving baccalaureate attainment

NASA Astrophysics Data System (ADS)

Carbajal, Sandy C.

Drawing from Latino/a Critical Race Theory and the related Community Cultural Wealth (CCW) model, I concentrate on three forms of CCW---aspirational, navigational, and resistance capital---for this qualitative study on the undergraduate experience of Latina students in Science, Technology, Engineering, and Mathematics (STEM) majors, focusing on strategies and achieving baccalaureate attainment. I interviewed ten Latina students and asked them questions regarding their educational experiences in STEM majors, what contributed to their degree completion, and the strategies they employed for achieving baccalaureate attainment. I identified and described six themes within the study (the underrepresentation of Latinas in STEM majors, the lack of preparation by academic programs for upper division courses, motivators, involvement, time management, and support networks) that, when combined, contributed to participants' degree attainment. This study concludes with implications for policy and practice that would allow universities to better assist Latinas in STEM majors to achieve baccalaureate attainment.

Major Radiations in the Evolution of Caviid Rodents: Reconciling Fossils, Ghost Lineages, and Relaxed Molecular Clocks

PubMed Central

Pérez, María Encarnación; Pol, Diego

2012-01-01

Background Caviidae is a diverse group of caviomorph rodents that is broadly distributed in South America and is divided into three highly divergent extant lineages: Caviinae (cavies), Dolichotinae (maras), and Hydrochoerinae (capybaras). The fossil record of Caviidae is only abundant and diverse since the late Miocene. Caviids belongs to Cavioidea sensu stricto (Cavioidea s.s.) that also includes a diverse assemblage of extinct taxa recorded from the late Oligocene to the middle Miocene of South America (“eocardiids”). Results A phylogenetic analysis combining morphological and molecular data is presented here, evaluating the time of diversification of selected nodes based on the calibration of phylogenetic trees with fossil taxa and the use of relaxed molecular clocks. This analysis reveals three major phases of diversification in the evolutionary history of Cavioidea s.s. The first two phases involve two successive radiations of extinct lineages that occurred during the late Oligocene and the early Miocene. The third phase consists of the diversification of Caviidae. The initial split of caviids is dated as middle Miocene by the fossil record. This date falls within the 95% higher probability distribution estimated by the relaxed Bayesian molecular clock, although the mean age estimate ages are 3.5 to 7 Myr older. The initial split of caviids is followed by an obscure period of poor fossil record (refered here as the Mayoan gap) and then by the appearance of highly differentiated modern lineages of caviids, which evidentially occurred at the late Miocene as indicated by both the fossil record and molecular clock estimates. Conclusions The integrated approach used here allowed us identifying the agreements and discrepancies of the fossil record and molecular clock estimates on the timing of the major events in cavioid evolution, revealing evolutionary patterns that would not have been possible to gather using only molecular or paleontological data alone. PMID

A unique large-scale undergraduate research experience in molecular systems biology for non-mathematics majors.

PubMed

Kappler, Ulrike; Rowland, Susan L; Pedwell, Rhianna K

2017-05-01

Systems biology is frequently taught with an emphasis on mathematical modeling approaches. This focus effectively excludes most biology, biochemistry, and molecular biology students, who are not mathematics majors. The mathematical focus can also present a misleading picture of systems biology, which is a multi-disciplinary pursuit requiring collaboration between biochemists, bioinformaticians, and mathematicians. This article describes an authentic large-scale undergraduate research experience (ALURE) in systems biology that incorporates proteomics, bacterial genomics, and bioinformatics in the one exercise. This project is designed to engage students who have a basic grounding in protein chemistry and metabolism and no mathematical modeling skills. The pedagogy around the research experience is designed to help students attack complex datasets and use their emergent metabolic knowledge to make meaning from large amounts of raw data. On completing the ALURE, participants reported a significant increase in their confidence around analyzing large datasets, while the majority of the cohort reported good or great gains in a variety of skills including "analysing data for patterns" and "conducting database or internet searches." An environmental scan shows that this ALURE is the only undergraduate-level system-biology research project offered on a large-scale in Australia; this speaks to the perceived difficulty of implementing such an opportunity for students. We argue however, that based on the student feedback, allowing undergraduate students to complete a systems-biology project is both feasible and desirable, even if the students are not maths and computing majors. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):235-248, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Molecular cloning, characterization, and expression of Cuc m 2, a major allergen in Cucumis melo

PubMed Central

Sankian, Mojtaba; Mahmoudi, Mahmoud; Varasteh, Abdol-Reza

2013-01-01

Background: Several studies reported the clinical features of IgE-mediated hypersensitivity after ingestion of melon. Melon allergy is a common IgE-mediated fruit allergy in Iran. This prompted us to investigate immunochemical and molecular properties of the major allergen in melon fruit, to compare the IgE-binding capacity of the natural protein with the recombinant allergen, and to determine cross-reactivity of the major allergen with closely-related allergens from other plants displaying clinical cross-reactivity with melon. Methods: Identification and molecular characterization of the major melon allergen were performed using IgE immunoblotting, allergen-specific ELISA, affinity-based purifications, cross-inhibition assays, cloning, and expression of the allergen in Escherichia coli. Results: Melon profilin was identified and isolated as a major IgE-binding component and designated as Cuc m 2. Sequencing corresponding cDNA revealed an open reading frame of 363 bp coding for 131 amino acid residues and two fragments of 171 bp and 383 bps for the 5’and 3’ UTRs, respectively. Significant cross-reactivity was found between melon profilin and Cynodon dactylon, tomato, peach, and grape profilins in cross-inhibition assays. Although the highest degree of amino acid identity was revealed with watermelon profilin, there was no significant cross-reactivity between melon and watermelon profilins. Conclusion: Melon profilin is the major IgE-binding component in melon extract, and the recombinant and natural forms exhibited similar IgE-binding capacities. A part of the fruit-fruit and pollen-fruit cross-reactions could be explained by the presence of this conserved protein; however, sequence homology provides insufficient information to predict IgE cross-reactivity of profilins. PMID:26989709

The impact of epilepsy on academic achievement in children with normal intelligence and without major comorbidities: A systematic review.

PubMed

Wo, S W; Ong, L C; Low, W Y; Lai, P S M

2017-10-01

To systematically examine published literature which assessed the prevalence of academic difficulties in children with epilepsy (CWE) of normal intelligence, and its associating factors. A search was conducted on five databases for articles published in English from 1980 till March 2015. Included were studies who recruited children (aged 5-18 years), with a diagnosis or newly/recurrent epilepsy, an intelligent quotient (IQ) of ≥70 or attending regular school, with or without a control group, which measured academic achievement using a standardised objective measure, and published in English. Excluded were children with learning difficulties, intellectual disabilities (IQ<70) and other comorbidities such as attention deficits hyperactive disorder or autism. Two pairs of reviewers extracted the data, and met to resolve any differences from the data extraction process. Twenty studies were included. The majority of the studies assessed "low achievement" whist only two studies used the IQ-achievement discrepancy definition of "underachievement". Fourteen studies (70%) reported that CWE had significantly lower academic achievement scores compared to healthy controls, children with asthma or reported norms. The remaining six studies (30%) did not report any differences. CWE had stable academic achievement scores over time (2-4 years), even among those whose seizure frequency improved. Higher parental education and children with higher IQ, and had better attention or had a positive attitude towards epilepsy, were associated with higher academic achievement score. Older children were found to have lower academic achievement score. In CWE of normal intelligence, the majority of published literature found that academic achievement was lower than controls or reported norms. The high percentages of low achievement in CWE, especially in the older age group, and the stability of scores even as seizure frequency improved, highlights the need for early screening of learning

Molecular epidemiology of tuberculosis: achievements and challenges to current knowledge.

PubMed Central

Murray, Megan; Nardell, Edward

2002-01-01

Over the past 10 years, molecular methods have become available with which to strain-type Mycobacterium tuberculosis. They have allowed researchers to study certain important but previously unresolved issues in the epidemiology of tuberculosis (TB). For example, some unsuspected microepidemics have been revealed and it has been shown that the relative contribution of recently acquired disease to the TB burden in many settings is far greater than had been thought. These findings have led to the strengthening of TB control. Other research has demonstrated the existence and described the frequency of exogenous reinfection in areas of high incidence. Much recent work has focused on the phenotypic variation among strains and has evaluated the relative transmissibility, virulence, and immunogenicity of different lineages of the organism. We summarize the recent achievements in TB epidemiology associated with the introduction of DNA fingerprinting techniques, and consider the implications of this technology for the design and analysis of epidemiological studies. PMID:12132006

Patient's Compliance on the Use of Extended Low Molecular Weight Heparin Post Major Pelvic Surgeries in Cancer Patients at King Hussein Cancer Center.

PubMed

Baba, M; Al-Masri, M; Salhab, M; El-Ghanem, M

2015-01-01

Effective Venous Thrombo-Embolism (VTE) prophylaxis is used in less than 50% of oncology patients despite its wide availability. Low molecular weight heparin (LMWH) as a daily injection is an essential tool for effective prophylaxis against deep vein thrombosis (DVT). Daily outpatient self-injection by the patients or their family members is common practice. The effectiveness of this measure depends on patient compliance. The purpose of this study is to determine the degree of compliance and the factors that affect compliance to the extended out-patient use of prophylactic LMWH for 1 month after major abdominal/pelvic surgeries in cancer patients at King Hussein Cancer Center (KHCC). Following major abdominal/pelvic surgeries, data on 160 cancer patients at KHCC from January 2007 until July 2012 were collected concerning knowledge of DVT and compliance with prophylactic self-injections by answering a questionnaire. We have achieved a high compliance rate, this was explained by the medical team's role in educating the patients about the risk of VTE and the importance of thromboprophylaxis. The compliance with self-injections was directly associated with younger age, employment and higher degree of education. The high compliance rate outside clinical trials can be achieved through comprehensive patient education by a well-qualified medical team, clarification of the importance of DVT prophylaxis and patients' support.

Technical Tension Between Achieving Particulate and Molecular Organic Environmental Cleanliness: Data from Astromaterial Curation Laboratories

NASA Technical Reports Server (NTRS)

Allton, J. H.; Burkett, P. J.

2011-01-01

NASA Johnson Space Center operates clean curation facilities for Apollo lunar, Antarctic meteorite, stratospheric cosmic dust, Stardust comet and Genesis solar wind samples. Each of these collections is curated separately due unique requirements. The purpose of this abstract is to highlight the technical tensions between providing particulate cleanliness and molecular cleanliness, illustrated using data from curation laboratories. Strict control of three components are required for curating samples cleanly: a clean environment; clean containers and tools that touch samples; and use of non-shedding materials of cleanable chemistry and smooth surface finish. This abstract focuses on environmental cleanliness and the technical tension between achieving particulate and molecular cleanliness. An environment in which a sample is manipulated or stored can be a room, an enclosed glovebox (or robotic isolation chamber) or an individual sample container.

Building a Bridge to Span the Minority-Majority Achievement Gap.

ERIC Educational Resources Information Center

Lanasa, Philip J., III; Potter, Jane Hopkins

A number of hypotheses have been advanced to explain why black students lag behind whites in school achievement. In the 1950s and 1960s, an environmental hypothesis emerged which attributed the achievement gap to environment. Environmentalists at this point were divided between those who felt the family determined achievement and those who felt…

On the Relationship among Critical Thinking, Language Learning Strategy Use and University Achievement of Iranian English as a Foreign Language Majors

ERIC Educational Resources Information Center

Afshar, Hassan Soodmand; Movassagh, Hossein

2017-01-01

The study investigated the relationship among critical thinking, strategy use and university achievement. To this end, 76 English major students sat the California Critical Thinking Skills Test and filled out Oxford's Strategy Inventory for Language Learning. Participants' Grade Point Averages were regarded as their university achievement. The…

Predicting Undergraduate Music Education Majors' Collegiate Achievement

ERIC Educational Resources Information Center

Rohwer, Debbie

2012-01-01

In order for teachers to guide students in their preparation to be music majors, it would be useful to know those musical components that best predict overall collegiate success. The purpose of this study was to measure the relationship of predictor variables (Lessons, Music History, Music Theory, and Piano) to collegiate grade point average (GPA)…

Molecular Genetic Analysis of Chlamydia Species.

PubMed

Sixt, Barbara S; Valdivia, Raphael H

2016-09-08

Species of Chlamydia are the etiologic agent of endemic blinding trachoma, the leading cause of bacterial sexually transmitted diseases, significant respiratory pathogens, and a zoonotic threat. Their dependence on an intracellular growth niche and their peculiar developmental cycle are major challenges to elucidating their biology and virulence traits. The last decade has seen tremendous advances in our ability to perform a molecular genetic analysis of Chlamydia species. Major achievements include the generation of large collections of mutant strains, now available for forward- and reverse-genetic applications, and the introduction of a system for plasmid-based transformation enabling complementation of mutations; expression of foreign, modified, or reporter genes; and even targeted gene disruptions. This review summarizes the current status of the molecular genetic toolbox for Chlamydia species and highlights new insights into their biology and new challenges in the nascent field of Chlamydia genetics.

TIDEL-II: first-line use of imatinib in CML with early switch to nilotinib for failure to achieve time-dependent molecular targets

PubMed Central

Yeung, David T.; Osborn, Michael P.; White, Deborah L.; Branford, Susan; Braley, Jodi; Herschtal, Alan; Kornhauser, Michael; Issa, Samar; Hiwase, Devendra K.; Hertzberg, Mark; Schwarer, Anthony P.; Filshie, Robin; Arthur, Christopher K.; Kwan, Yiu Lam; Trotman, Judith; Forsyth, Cecily J.; Taper, John; Ross, David M.; Beresford, Jennifer; Tam, Constantine; Mills, Anthony K.; Grigg, Andrew P.

2015-01-01

The Therapeutic Intensification in De Novo Leukaemia (TIDEL)-II study enrolled 210 patients with chronic phase chronic myeloid leukemia (CML) in two equal, sequential cohorts. All started treatment with imatinib 600 mg/day. Imatinib plasma trough level was performed at day 22 and if <1000 ng/mL, imatinib 800 mg/day was given. Patients were then assessed against molecular targets: BCR-ABL1 ≤10%, ≤1%, and ≤0.1% at 3, 6, and 12 months, respectively. Cohort 1 patients failing any target escalated to imatinib 800 mg/day, and subsequently switched to nilotinib 400 mg twice daily for failing the same target 3 months later. Cohort 2 patients failing any target switched to nilotinib directly, as did patients with intolerance or loss of response in either cohort. At 2 years, 55% of patients remained on imatinib, and 30% on nilotinib. Only 12% were >10% BCR-ABL1 at 3 months. Confirmed major molecular response was achieved in 64% at 12 months and 73% at 24 months. MR4.5 (BCR-ABL1 ≤0.0032%) at 24 months was 34%. Overall survival was 96% and transformation-free survival was 95% at 3 years. This trial supports the feasibility and efficacy of an imatinib-based approach with selective, early switching to nilotinib. This trial was registered at www.anzctr.org.au as #12607000325404. PMID:25519749

Implementation of cascade logic gates and majority logic gate on a simple and universal molecular platform.

PubMed

Gao, Jinting; Liu, Yaqing; Lin, Xiaodong; Deng, Jiankang; Yin, Jinjin; Wang, Shuo

2017-10-25

Wiring a series of simple logic gates to process complex data is significantly important and a large challenge for untraditional molecular computing systems. The programmable property of DNA endows its powerful application in molecular computing. In our investigation, it was found that DNA exhibits excellent peroxidase-like activity in a colorimetric system of TMB/H 2 O 2 /Hemin (TMB, 3,3', 5,5'-Tetramethylbenzidine) in the presence of K + and Cu 2+ , which is significantly inhibited by the addition of an antioxidant. According to the modulated catalytic activity of this DNA-based catalyst, three cascade logic gates including AND-OR-INH (INHIBIT), AND-INH and OR-INH were successfully constructed. Interestingly, by only modulating the concentration of Cu 2+ , a majority logic gate with a single-vote veto function was realized following the same threshold value as that of the cascade logic gates. The strategy is quite straightforward and versatile and provides an instructive method for constructing multiple logic gates on a simple platform to implement complex molecular computing.

[Analysis and outlook on teaching status of Molecular Pharmacognosy].

PubMed

Bi, Yu-xia; Xu, Hai-yu; Tong, Yan; Cui, Shu-zhen; Li, Hai-yan; Liu, Chang-xiao

2015-09-01

The teaching status of Molecular Pharmacognosy in 28 institutions in China was investigated by questionnaire and the survey data was analyzed by SPSS. Research contents included course beginning years, majors, class hours, characteristics of the course, teaching ways, the theory and practice contents, evaluation modes, selection of teaching material, teaching achievements, teachers and so on for undergraduates and graduates. Research results showed that with 20 years' development, Molecular Pharmacognosy had been offered for both undergraduate and graduate students in at least 20 colleges and universities and Molecular Pharmacognosy education in China showed good development momentum. At the same time, to promote the development of Molecular Pharmacognosy further, investment for it should be increased and practical teaching condition should be improved.

The More Things Change, the More They Stay the Same? Examining Gender Equality in Prior Achievement and Entry into STEM College Majors over Time.

PubMed

Riegle-Crumb, Catherine; King, Barbara; Grodsky, Eric; Muller, Chandra

2012-12-01

This article investigates the empirical basis for often-repeated arguments that gender differences in entrance into STEM majors are largely explained by disparities in prior achievement. Analyses use data from three national cohorts of college matriculates across three decades to consider differences across several indicators of high school math and science achievement at the mean and also at the top of the test distribution. Analyses also examine the different comparative advantages men and women enjoy in math/science vs. English/reading. Regardless of how prior achievement is measured, very little of the strong and persistent gender gap in physical science and engineering majors over time is explained. Findings highlight the limitations of theories focusing on gender differences in skills and suggest directions for future research.

Clinical Efficacy and Safety of First-Line Dasatinib Therapy and the Relevance of Velocity of BCR-ABL1 Transcript Decline for Achievement of Molecular Responses in Newly Diagnosed Chronic-Phase Chronic Myeloid Leukemia: Report from the Juntendo Yamanashi Cooperative Study Group.

PubMed

Takaku, Tomoiku; Iriyama, Noriyoshi; Mitsumori, Toru; Sato, Eriko; Gotoh, Akihiko; Kirito, Keita; Noguchi, Masaaki; Koike, Michiaki; Sakamoto, Junichi; Oba, Koji; Komatsu, Norio

2018-01-01

The use of tyrosine kinase inhibitors led to an improvement in the prognoses of patients with chronic myeloid leukemia (CML). The aims of this study were to investigate the efficacy and safety of dasatinib in Japanese patients and to explore the factors that affect the achievement of molecular responses. The primary endpoint was a major molecular response (MMR) by 12 months. The halving time for BCR-ABL1 transcripts was calculated using transcript levels. Thirty-two patients with chronic-phase CML (CML-CP) were enrolled and 30 received 100 mg dasatinib once daily. At 24 months of follow-up, 21 (72%) and 24 (83%) patients achieved an MMR by 12 and 24 months, respectively; the rates of a deep molecular response (DMR) by 12 and 24 months were 48 and 59%, respectively. A shorter halving time of BCR-ABL1 transcripts (≤10.6 days) accurately predicted both an MMR and a DMR. The incidence of pleural effusion was 50%. Our study reconfirmed the efficacy and safety of dasatinib treatment in Japanese patients with newly diagnosed CML-CP. In addition, the usefulness of the halving time of BCR-ABL1 transcripts was validated. These data emphasize the significance of an early treatment response in achieving a DMR during dasatinib therapy. © 2017 S. Karger AG, Basel.

Conceptual framework for drought phenotyping during molecular breeding.

PubMed

Salekdeh, Ghasem Hosseini; Reynolds, Matthew; Bennett, John; Boyer, John

2009-09-01

Drought is a major threat to agricultural production and drought tolerance is a prime target for molecular approaches to crop improvement. To achieve meaningful results, these approaches must be linked with suitable phenotyping protocols at all stages, such as the screening of germplasm collections, mutant libraries, mapping populations, transgenic lines and breeding materials and the design of OMICS and quantitative trait loci (QTLs) experiments. Here we present a conceptual framework for molecular breeding for drought tolerance based on the Passioura equation of expressing yield as the product of water use (WU), water use efficiency (WUE) and harvest index (HI). We identify phenotyping protocols that address each of these factors, describe their key features and illustrate their integration with different molecular approaches.

A decade of molecular cell biology: achievements and challenges.

PubMed

Akhtar, Asifa; Fuchs, Elaine; Mitchison, Tim; Shaw, Reuben J; St Johnston, Daniel; Strasser, Andreas; Taylor, Susan; Walczak, Claire; Zerial, Marino

2011-09-23

Nature Reviews Molecular Cell Biology celebrated its 10-year anniversary during this past year with a series of specially commissioned articles. To complement this, here we have asked researchers from across the field for their insights into how molecular cell biology research has evolved during this past decade, the key concepts that have emerged and the most promising interfaces that have developed. Their comments highlight the broad impact that particular advances have had, some of the basic understanding that we still require, and the collaborative approaches that will be essential for driving the field forward.

Doping-free white organic light-emitting diodes without blue molecular emitter: An unexplored approach to achieve high performance via exciplex emission

NASA Astrophysics Data System (ADS)

Luo, Dongxiang; Xiao, Ye; Hao, Mingming; Zhao, Yu; Yang, Yibin; Gao, Yuan; Liu, Baiquan

2017-02-01

Doping-free white organic light-emitting diodes (DF-WOLEDs) are promising for the low-cost commercialization because of their simplified device structures. However, DF-WOLEDs reported thus far in the literature are based on the use of blue single molecular emitters, whose processing can represent a crucial point in device manufacture. Herein, DF-WOLEDs without the blue single molecular emitter have been demonstrated by managing a blue exciplex system. For the single-molecular-emitter (orange or yellow emitter) DF-WOLEDs, (i) a color rendering index (CRI) of 81 at 1000 cd/m2 can be obtained, which is one of the highest for the single-molecular-emitter WOLEDs, or (ii) a high efficiency of 35.4 lm/W can be yielded. For the dual-molecular-emitter (yellow/red emitters) DF-WOLED, a high CRI of 85 and low correlated color temperature of 2376 K at 1000 cd/m2 have been simultaneously achieved, which has not been reported by previous DF-WOLEDs. Such presented findings may unlock an alternative avenue to the simplified but high-performance WOLEDs.

Molecular analysis of FRIGIDA, a major determinant of natural variation in Arabidopsis flowering time.

PubMed

Johanson, U; West, J; Lister, C; Michaels, S; Amasino, R; Dean, C

2000-10-13

Vernalization, the acceleration of flowering by a long period of cold temperature, ensures that many plants overwinter vegetatively and flower in spring. In Arabidopsis, allelic variation at the FRIGIDA (FRI) locus is a major determinant of natural variation in flowering time. Dominant alleles of FRI confer late flowering, which is reversed to earliness by vernalization. We cloned FRI and analyzed the molecular basis of the allelic variation. Most of the early-flowering ecotypes analyzed carry FRI alleles containing one of two different deletions that disrupt the open reading frame. Loss-of-function mutations at FRI have thus provided the basis for the evolution of many early-flowering ecotypes.

Skin: Major target organ of allergic reactions to small molecular weight compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merk, Hans F.; Baron, Jens M.; Neis, Mark M.

2007-11-01

Skin is a major target organ for allergic reactions to small molecular weight compounds. Drug allergic reactions may be life-threatening such as in the case of anaphylactic reactions or bullous drug reactions and occur in about 5% of all hospitalized patients. Allergic contact dermatitis has an enormous influence on the social life of the patient because it is the most frequent reason for occupational skin diseases and the treatment and prevention of this disease cost approximately Euro 3 billion per year in Germany. The different proposed pathophysiological pathways leading to a drug eruption are discussed in this paper. All majormore » enzymes which are involved in the metabolism of xenobiotica were shown to be present in skin. Evidence supporting the role of metabolism in the development of drug allergy and allergic contact dermatitis is demonstrated in the example of sulphonamides and fragrances.« less

A decade of molecular cell biology: achievements and challenges

PubMed Central

Akhtar, Asifa; Fuchs, Elaine; Mitchison, Tim; Shaw, Reuben J.; St Johnston, Daniel; Strasser, Andreas; Taylor, Susan; Walczak, Claire; Zerial, Marino

2012-01-01

Nature Reviews Molecular Cell Biology celebrated its 10-year anniversary during this past year with a series of specially commissioned articles. To complement this, here we have asked researchers from across the field for their insights into how molecular cell biology research has evolved during this past decade, the key concepts that have emerged and the most promising interfaces that have developed. Their comments highlight the broad impact that particular advances have had, some of the basic understanding that we still require, and the collaborative approaches that will be essential for driving the field forward. PMID:21941276

Design of a 15N Molecular Unit to Achieve Long Retention of Hyperpolarized Spin State

NASA Astrophysics Data System (ADS)

Nonaka, Hiroshi; Hirano, Masashi; Imakura, Yuki; Takakusagi, Yoichi; Ichikawa, Kazuhiro; Sando, Shinsuke

2017-01-01

Nuclear hyperpolarization is a phenomenon that can be used to improve the sensitivity of magnetic resonance molecular sensors. However, such sensors typically suffer from short hyperpolarization lifetime. Herein we report that [15N, D14]trimethylphenylammonium (TMPA) has a remarkably long spin-lattice relaxation time (1128 s, 14.1 T, 30 °C, D2O) on its 15N nuclei and achieves a long retention of the hyperpolarized state. [15N, D14]TMPA-based hyperpolarized sensor for carboxylesterase allowed the highly sensitive analysis of enzymatic reaction by 15N NMR for over 40 min in phophate-buffered saline (H2O, pH 7.4, 37 °C).

Carboxylate-based molecular magnet: One path toward achieving stable quantum correlations at room temperature

DOE PAGES

Cruz, C.; Soares-Pinto, D. O.; Brandão, P.; ...

2016-03-07

The control of quantum correlations in solid-state systems by means of material engineering is a broad avenue to be explored, since it makes possible steps toward the limits of quantum mechanics and the design of novel materials with applications on emerging quantum technologies. This letter explores the potential of molecular magnets to be prototypes of materials for quantum information technology in this context. More precisely, we engineered a material and from its geometric quantum discord we found significant quantum correlations up to 9540 K (even without entanglement); and, a pure singlet state occupied up to around 80 K (above liquidmore » nitrogen temperature), additionally. Our results could only be achieved due to the carboxylate group promoting a metal-to-metal huge magnetic interaction.« less

A Single Molecular Diels-Alder Crosslinker for Achieving Recyclable Cross-Linked Polymers.

PubMed

Chen, Shengli; Wang, Fenfen; Peng, Yongjin; Chen, Tiehong; Wu, Qiang; Sun, Pingchuan

2015-09-01

A triol-functional crosslinker combining the thermoreversible properties of Diels-Alder (DA) adducts in one molecule is designed, synthesized, and used as an ideal substitute of a traditional crosslinker to prepare thermal recyclable cross-linked polyurethanes with excellent mechanical properties and recyclability in a very simple and efficient way. The recycle property of these materials achieved by the DA/retro-DA reaction at a suitable temperature is verified by differential scanning calorimetry and in situ variable temperature solid-state NMR experiments during the cyclic heating and cooling processes. The thermal recyclability and remending ability of the bulk polyurethanes is demonstrated by three polymer processing methods, including hot-press molding, injection molding, and solution casting. It is notable that all the recycled cross-linked polymers display nearly invariable elongation/stress at break compared to the as-synthesized samples. Further end-group functionalization of this single molecular DA crosslinker provides the potential in preparing a wide range of recyclable cross-linked polymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular cloning, expression and characterization of Pru a 1, the major cherry allergen.

PubMed

Scheurer, S; Metzner, K; Haustein, D; Vieths, S

1997-06-01

A high percentage of birch pollen allergic patients experiences food hypersensitivity reactions after ingestion of several fruits and vegetables. Previous work demonstrated common epitopes on an allergen of Mr 18,000 from sweet cherry (Prunus avium) and Bet v 1, the major allergen from birch pollen. N-terminal amino acid sequencing showed a sequence identity of 67% with Bet v 1. Here we report the cloning and cDNA sequencing of this cherry allergen. The entire deduced amino acid sequence described a protein of Mr 17,700 with 59.1% identity to Bet v 1. High degrees of identity in the range of 40 to 60% were also found with related allergens from other kinds of tree pollen and plant foods as well as with stress-induced proteins from food plants such as parsley, potato and soya. The coding DNA of the cherry protein was cloned into vector pET-16b and expressed in E. coli strain BL21(DE3) as a His-tag fusion protein. As shown by SDS-PAGE, the apparent molecular masses of the nonfusion protein and the natural allergen were identical. The fusion protein showed high IgE binding potency when sera from patients allergic to cherry were tested by immunoblotting and enzyme allergosorbent tests. Moreover, it cross-reacted strongly with IgE specific for the natural counterpart and for Bet v 1. The high biological activity of the recombinant fusion protein was further confirmed by the induction of a strong histamine release in basophils from cherry-allergic patients. Since sera from 17/19 of such patients contained IgE against this allergen it was classified as a major allergen and named Pru a 1. Recombinant Pru a 1 mimics most of the allergenic potency of cherry extract and hence could be a useful tool for studying the molecular and immunological properties of pollen related food allergens.

Major achievements of evidence-based traditional Chinese medicine in treating major diseases.

PubMed

Chao, Jung; Dai, Yuntao; Verpoorte, Robert; Lam, Wing; Cheng, Yung-Chi; Pao, Li-Heng; Zhang, Wei; Chen, Shilin

2017-09-01

A long history of use and extensive documentation of the clinical practices of traditional Chinese medicine resulted in a considerable number of classical preparations, which are still widely used. This heritage of our ancestors provides a unique resource for drug discovery. Already, a number of important drugs have been developed from traditional medicines, which in fact form the core of Western pharmacotherapy. Therefore, this article discusses the differences in drug development between traditional medicine and Western medicine. Moreover, the article uses the discovery of artemisinin as an example that illustrates the "bedside-bench-bedside" approach to drug discovery to explain that the middle way for drug development is to take advantage of the best features of these two distinct systems and compensate for certain weaknesses in each. This article also summarizes evidence-based traditional medicines and discusses quality control and quality assessment, the crucial steps in botanical drug development. Herbgenomics may provide effective tools to clarify the molecular mechanism of traditional medicines in the botanical drug development. The totality-of-the-evidence approach used by the U.S. Food and Drug Administration for botanical products provides the directions on how to perform quality control from the field throughout the entire production process. Copyright © 2017 Elsevier Inc. All rights reserved.

ALMA Achieves Major Milestone With Antenna-Link Success

NASA Astrophysics Data System (ADS)

2007-03-01

The Atacama Large Millimeter/submillimeter Array (ALMA), an international telescope project, reached a major milestone on March 2, when two ALMA prototype antennas were first linked together as an integrated system to observe an astronomical object. The milestone achievement, technically termed "First Fringes," came at the ALMA Test Facility (ATF) on the grounds of the National Radio Astronomy Observatory's (NRAO) Very Large Array (VLA) radio telescope in New Mexico. NRAO is a facility of the National Science Foundation (NSF), managed by Associated Universities, Incorporated (AUI). AUI also is designated by NSF as the North American Executive for ALMA. ALMA Test Facility ALMA Test Facility, New Mexico: VertexRSI antenna, left; AEC antenna, right. CREDIT: Drew Medlin, NRAO/AUI/NSF Click on image for page of graphics and full information Faint radio waves emitted by the planet Saturn were collected by the two ALMA antennas, then processed by new, state-of-the-art electronics to turn the two antennas into a single, high-resolution telescope system, called an interferometer. Such pairs of antennas are the basic building blocks of multi-antenna imaging systems such as ALMA and the VLA. In such a system, each antenna is combined electronically with every other antenna to form a multitude of pairs. Each pair contributes unique information that is used to build a highly-detailed image of the astronomical object under observation. When completed in 2012, ALMA will have 66 antennas. The successful Saturn observation began at 7:13 p.m., U.S. Mountain Time Friday (0213 UTC Saturday). The planet's radio emissions at a frequency of 104 GigaHertz (GHz) were tracked by the ALMA system for more than an hour. "Our congratulations go to the dedicated team of scientists, engineers and technicians who produced this groundbreaking achievement for ALMA. Much hard work and many long hours went into this effort, and we appreciate it all. This team should be very proud today," said NRAO

Molecular electronics: The technology of sixth generation computers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jarvis, M.T.; Miller, R.K.

1987-01-01

In February 1986, Japan began the 6th Generation project. At the 1987 Economic Summit in Venice, Prime Minister Yashuhiro Makasone opened the project to world collaboration. A project director suggests that the 6th Generation ''may just be a turning point for human society.'' The major rationale for building molecular electronic devices is to achieve advances in computational densities and speeds. Proposed chromophore chains for molecular-scale chips, for example, could be spaced closer than today's silicone elements by a factor of almost 100. This book describes the research and proposed designs for molecular electronic devices and computers. It examines specific potentialmore » applications and the relationship to molecular electronics to silicon technology and presents the first published survey of experts on research issues, applications, and forecast of future developments and also includes market forecast. An interesting suggestion of the survey is that the chemical industry may become a significant factor in the computer industry as the sixth generation unfolds.« less

Molecular medicine: a path towards a personalized medicine.

PubMed

Miranda, Debora Marques de; Mamede, Marcelo; Souza, Bruno Rezende de; Almeida Barros, Alexandre Guimarães de; Magno, Luiz Alexandre; Alvim-Soares, Antônio; Rosa, Daniela Valadão; Castro, Célio José de; Malloy-Diniz, Leandro; Gomez, Marcus Vinícius; Marco, Luiz Armando De; Correa, Humberto; Romano-Silva, Marco Aurélio

2012-03-01

Psychiatric disorders are among the most common human illnesses; still, the molecular and cellular mechanisms underlying their complex pathophysiology remain to be fully elucidated. Over the past 10 years, our group has been investigating the molecular abnormalities in major signaling pathways involved in psychiatric disorders. Recent evidences obtained by the Instituto Nacional de Ciência e Tecnologia de Medicina Molecular (National Institute of Science and Technology - Molecular Medicine, INCT-MM) and others using behavioral analysis of animal models provided valuable insights into the underlying molecular alterations responsible for many complex neuropsychiatric disorders, suggesting that "defects" in critical intracellular signaling pathways have an important role in regulating neurodevelopment, as well as in pathophysiology and treatment efficacy. Resources from the INCT have allowed us to start doing research in the field of molecular imaging. Molecular imaging is a research discipline that visualizes, characterizes, and quantifies the biologic processes taking place at cellular and molecular levels in humans and other living systems through the results of image within the reality of the physiological environment. In order to recognize targets, molecular imaging applies specific instruments (e.g., PET) that enable visualization and quantification in space and in real-time of signals from molecular imaging agents. The objective of molecular medicine is to individualize treatment and improve patient care. Thus, molecular imaging is an additional tool to achieve our ultimate goal.

Molecular modeling of class I and II alleles of the major histocompatibility complex in Salmo salar.

PubMed

Cárdenas, Constanza; Bidon-Chanal, Axel; Conejeros, Pablo; Arenas, Gloria; Marshall, Sergio; Luque, F Javier

2010-12-01

Knowledge of the 3D structure of the binding groove of major histocompatibility (MHC) molecules, which play a central role in the immune response, is crucial to shed light into the details of peptide recognition and polymorphism. This work reports molecular modeling studies aimed at providing 3D models for two class I and two class II MHC alleles from Salmo salar (Sasa), as the lack of experimental structures of fish MHC molecules represents a serious limitation to understand the specific preferences for peptide binding. The reliability of the structural models built up using bioinformatic tools was explored by means of molecular dynamics simulations of their complexes with representative peptides, and the energetics of the MHC-peptide interaction was determined by combining molecular mechanics interaction energies and implicit continuum solvation calculations. The structural models revealed the occurrence of notable differences in the nature of residues at specific positions in the binding groove not only between human and Sasa MHC proteins, but also between different Sasa alleles. Those differences lead to distinct trends in the structural features that mediate the binding of peptides to both class I and II MHC molecules, which are qualitatively reflected in the relative binding affinities. Overall, the structural models presented here are a valuable starting point to explore the interactions between MHC receptors and pathogen-specific interactions and to design vaccines against viral pathogens.

Interfacial Molecular Packing Determines Exciton Dynamics in Molecular Heterostructures: The Case of Pentacene-Perfluoropentacene.

PubMed

Rinn, Andre; Breuer, Tobias; Wiegand, Julia; Beck, Michael; Hübner, Jens; Döring, Robin C; Oestreich, Michael; Heimbrodt, Wolfram; Witte, Gregor; Chatterjee, Sangam

2017-12-06

The great majority of electronic and optoelectronic devices depend on interfaces between p-type and n-type semiconductors. Finding matching donor-acceptor systems in molecular semiconductors remains a challenging endeavor because structurally compatible molecules may not necessarily be suitable with respect to their optical and electronic properties, and the large exciton binding energy in these materials may favor bound electron-hole pairs rather than free carriers or charge transfer at an interface. Regardless, interfacial charge-transfer exciton states are commonly considered as an intermediate step to achieve exciton dissociation. The formation efficiency and decay dynamics of such states will strongly depend on the molecular makeup of the interface, especially the relative alignment of donor and acceptor molecules. Structurally well-defined pentacene-perfluoropentacene heterostructures of different molecular orientations are virtually ideal model systems to study the interrelation between molecular packing motifs at the interface and their electronic properties. Comparing the emission dynamics of the heterosystems and the corresponding unitary films enables accurate assignment of every observable emission signal in the heterosystems. These heterosystems feature two characteristic interface-specific luminescence channels at around 1.4 and 1.5 eV that are not observed in the unitary samples. Their emission strength strongly depends on the molecular alignment of the respective donor and acceptor molecules, emphasizing the importance of structural control for device construction.

Molecular Pathophysiology of Hepatic Glucose Production

PubMed Central

Sharabi, Kfir; Tavares, Clint D. J.; Rines, Amy K.; Puigserver, Pere

2015-01-01

Maintaining blood glucose concentration within a relatively narrow range through periods of fasting or excess nutrient availability is essential to the survival of the organism. This is achieved through an intricate balance between glucose uptake and endogenous glucose production to maintain constant glucose concentrations. The liver plays a major role in maintaining normal whole body glucose levels by regulating the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis), thus controlling the levels of hepatic glucose release. Aberrant regulation of hepatic glucose production (HGP) can result in deleterious clinical outcomes, and excessive HGP is a major contributor to the hyperglycemia observed in Type 2 diabetes mellitus (T2DM). Indeed, adjusting glycaemia as close as possible to a non-diabetic range is the foremost objective in the medical treatment of patients with T2DM and is currently achieved in the clinic primarily through suppression of HGP. Here, we review the molecular mechanisms controlling HGP in response to nutritional and hormonal signals and discuss how these signals are altered in T2DM. PMID:26549348

Research advances in major cereal crops for adaptation to abiotic stresses

PubMed Central

Maiti, RK; Satya, Pratik

2014-01-01

With devastating increase in population there is a great necessity to increase crop productivity of staple crops but the productivity is greatly affected by various abiotic stress factors such as drought, salinity. An attempt has been made a brief account on abiotic stress resistance of major cereal crops viz. In spite of good successes obtained on physiological and use molecular biology, the benefits of this high cost technology are beyond the reach of developing countries. This review discusses several morphological, anatomical, physiological, biochemical and molecular mechanisms of major cereal crops related to the adaptation of these crop to abiotic stress factors. It discusses the effect of abiotic stresses on physiological processes such as flowering, grain filling and maturation and plant metabolisms viz. photosynthesis, enzyme activity, mineral nutrition, and respiration. Though significant progress has been attained on the physiological, biochemical basis of resistance to abiotic stress factors, very little progress has been achieved to increase productivity under sustainable agriculture. Therefore, there is a great necessity of inter-disciplinary research to address this issue and to evolve efficient technology and its transfer to the farmers’ fields. PMID:25523172

Research advances in major cereal crops for adaptation to abiotic stresses.

PubMed

Maiti, R K; Satya, Pratik

2014-01-01

With devastating increase in population there is a great necessity to increase crop productivity of staple crops but the productivity is greatly affected by various abiotic stress factors such as drought, salinity. An attempt has been made a brief account on abiotic stress resistance of major cereal crops viz. In spite of good successes obtained on physiological and use molecular biology, the benefits of this high cost technology are beyond the reach of developing countries. This review discusses several morphological, anatomical, physiological, biochemical and molecular mechanisms of major cereal crops related to the adaptation of these crop to abiotic stress factors. It discusses the effect of abiotic stresses on physiological processes such as flowering, grain filling and maturation and plant metabolisms viz. photosynthesis, enzyme activity, mineral nutrition, and respiration. Though significant progress has been attained on the physiological, biochemical basis of resistance to abiotic stress factors, very little progress has been achieved to increase productivity under sustainable agriculture. Therefore, there is a great necessity of inter-disciplinary research to address this issue and to evolve efficient technology and its transfer to the farmers' fields.

Concordance between actual and pharmacogenetic predicted desvenlafaxine dose needed to achieve remission in major depressive disorder: a 10-week open-label study.

PubMed

Bousman, Chad A; Müller, Daniel J; Ng, Chee H; Byron, Keith; Berk, Michael; Singh, Ajeet B

2017-01-01

Pharmacogenetic-based dosing support tools have been developed to personalize antidepressant-prescribing practice. However, the clinical validity of these tools has not been adequately tested, particularly for specific antidepressants. To examine the concordance between the actual dose and a polygene pharmacogenetic predicted dose of desvenlafaxine needed to achieve symptom remission. A 10-week, open-label, prospective trial of desvenlafaxine among Caucasian adults with major depressive disorder (n=119) was conducted. Dose was clinically adjusted and at the completion of the trial, the clinical dose needed to achieve remission was compared with the predicted dose needed to achieve remission. Among remitters (n=95), there was a strong concordance (Kendall's τ-b=0.84, P=0.0001; Cohen's κ=0.82, P=0.0001) between the actual and the predicted dose need to achieve symptom remission, showing high sensitivity (≥85%), specificity (≥86%), and accuracy (≥89%) of the tool. Findings provide initial evidence for the clinical validity of a polygene pharmacogenetic-based tool for desvenlafaxine dosing.

Charging-induced asymmetry in molecular conductors

NASA Astrophysics Data System (ADS)

Zahid, F.; Ghosh, A. W.; Paulsson, M.; Polizzi, E.; Datta, S.

2004-12-01

We investigate the origin of asymmetry in various measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry, with particular focus on a recent break junction measurement. We argue that such asymmetry arises due to unequal coupling with the contacts and a consequent difference in charging effects, which can only be captured in a self-consistent model for molecular conduction. The direction of the asymmetry depends on the sign of the majority carriers in the molecule. For conduction through highest occupied molecular orbitals (i.e., HOMO or p -type conduction), the current is smaller for positive voltage on the stronger contact, while for conduction through lowest unoccupied molecular orbitals (i.e., LUMO or n -type conduction), the sense of the asymmetry is reversed. Within an extended Hückel description of the molecular chemistry and the contact microstructure (with two adjustable parameters, the position of the Fermi energy and the sulphur-gold bond length), an appropriate description of Poisson’s equation, and a self-consistently coupled nonequilibrium Green’s function description of transport, we achieve good agreement between theoretical and experimental I-V characteristics, both in shape as well as overall magnitude.

Association of 5-HTTLPR Polymorphism with the Nursing Diagnoses and the Achievement of Nursing Outcomes in Patients with Major Depression.

PubMed

Prokofieva, Margarita; Karadima, Georgia; Koukia, Evmorfia; Michou, Vassiliki; Kyprianidou, Chrysoula; Papageorgiou, Chrysovalantis V; Alexiadis, Evangelos; Constantoulakis, Pantelis; Dikeos, Dimitris

2017-10-01

The aim of this study is to investigate whether a 44-base-pair insertion/deletion polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) is associated with the nursing diagnoses and the achievement of the desired nursing outcomes in inpatients with major depression. Thirty five patients were evaluated. The nursing diagnoses of risk for suicide and imbalanced nutrition are reported less often in homozygotes of the high-expressing gene (L A ). Carriers of the low-expressing genes (L G or S) have a worse response to interventions which aim to increase low self-esteem, indicating that they may need more intensive care in order to achieve the desired outcome. Genetics in psychiatric nursing could help refine personalized care, however further studies with large sample sizes and multiple gene evaluations are needed.

Achieving Reversible H2/H+ Interconversion at Room Temperature with Enzyme-Inspired Molecular Complexes: A Mechanistic Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Priyadarshani, Nilusha; Dutta, Arnab; Ginovska-Pangovska, Bojana

Inspired by the contribution of the protein scaffold to the efficiency with which enzymes function, we report the first molecular complex that is reversible for electrocatalytic H2 production/oxidation at room temperature in methanol. [Ni(PCy2NPhe2)2]2+ (CyPhe; PR2NR’2 = 1,5-diaza-3,7-diphosphacyclooctane, Cy=cyclohexyl, Phe=phenylalanine), shows reversible behavior in acidic methanol with peripheral phenylalanine groups providing key contributions to the catalytic behavior. The importance of the aromatic rings is implicated in achieving reversibility, based on the lack of reversibility of similar complexes, [Ni(PCy2NAmino Acid2)2]2+, containing arginine (CyArg) or glycine (CyGly). A complex with an added OH group on the ring, (CyTyr; Tyr=Tyrosine), also shows similarmore » behavior. NMR studies reveal a significantly slower rate of chair-boat isomerization for the CyPhe relative to other derivatives, suggesting that the aromatic groups provide structural control by interacting with each other, an observation supported by molecular dynamics studies. NMR studies also show extremely fast proton movement, with a proton pathway from the Ni-H through the pendant amine to the –COOH group. Further, studies of acomplex without the –COOH group, [Ni(PCy2NTym2)2]2+ (CyTym; Tym=Tyramine), are not reversible and have slow proton movement from the pendant amine, demonstrating the essential nature of the –COOH group in achieving reversibility. Finally, methanol is demonstrated to play a critical contributing role. The influence of multiple factors on reversibility for this synthetic catalyst is a demonstration of the intricate interplay between the first, second, and outer coordination spheres and resembles the complexity observed in metalloenzymes.« less

Molecular Momentum Transport at Fluid-Solid Interfaces in MEMS/NEMS: A Review

PubMed Central

Cao, Bing-Yang; Sun, Jun; Chen, Min; Guo, Zeng-Yuan

2009-01-01

This review is focused on molecular momentum transport at fluid-solid interfaces mainly related to microfluidics and nanofluidics in micro-/nano-electro-mechanical systems (MEMS/NEMS). This broad subject covers molecular dynamics behaviors, boundary conditions, molecular momentum accommodations, theoretical and phenomenological models in terms of gas-solid and liquid-solid interfaces affected by various physical factors, such as fluid and solid species, surface roughness, surface patterns, wettability, temperature, pressure, fluid viscosity and polarity. This review offers an overview of the major achievements, including experiments, theories and molecular dynamics simulations, in the field with particular emphasis on the effects on microfluidics and nanofluidics in nanoscience and nanotechnology. In Section 1 we present a brief introduction on the backgrounds, history and concepts. Sections 2 and 3 are focused on molecular momentum transport at gas-solid and liquid-solid interfaces, respectively. Summary and conclusions are finally presented in Section 4. PMID:20087458

Molecular diagnostics of myeloproliferative neoplasms.

PubMed

Langabeer, Stephen E; Andrikovics, Hajnalka; Asp, Julia; Bellosillo, Beatriz; Carillo, Serge; Haslam, Karl; Kjaer, Lasse; Lippert, Eric; Mansier, Olivier; Oppliger Leibundgut, Elisabeth; Percy, Melanie J; Porret, Naomi; Palmqvist, Lars; Schwarz, Jiri; McMullin, Mary F; Schnittger, Susanne; Pallisgaard, Niels; Hermouet, Sylvie

2015-10-01

Since the discovery of the JAK2 V617F mutation in the majority of the myeloproliferative neoplasms (MPN) of polycythemia vera, essential thrombocythemia and primary myelofibrosis ten years ago, further MPN-specific mutational events, notably in JAK2 exon 12, MPL exon 10 and CALR exon 9 have been identified. These discoveries have been rapidly incorporated into evolving molecular diagnostic algorithms. Whilst many of these mutations appear to have prognostic implications, establishing MPN diagnosis is of immediate clinical importance with selection, implementation and the continual evaluation of the appropriate laboratory methodology to achieve this diagnosis similarly vital. The advantages and limitations of these approaches in identifying and quantitating the common MPN-associated mutations are considered herein with particular regard to their clinical utility. The evolution of molecular diagnostic applications and platforms has occurred in parallel with the discovery of MPN-associated mutations, and it therefore appears likely that emerging technologies such as next-generation sequencing and digital PCR will in the future play an increasing role in the molecular diagnosis of MPN. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Concordance between actual and pharmacogenetic predicted desvenlafaxine dose needed to achieve remission in major depressive disorder: a 10-week open-label study

PubMed Central

Müller, Daniel J.; Ng, Chee H.; Byron, Keith; Berk, Michael; Singh, Ajeet B.

2017-01-01

Background Pharmacogenetic-based dosing support tools have been developed to personalize antidepressant-prescribing practice. However, the clinical validity of these tools has not been adequately tested, particularly for specific antidepressants. Objective To examine the concordance between the actual dose and a polygene pharmacogenetic predicted dose of desvenlafaxine needed to achieve symptom remission. Materials and methods A 10-week, open-label, prospective trial of desvenlafaxine among Caucasian adults with major depressive disorder (n=119) was conducted. Dose was clinically adjusted and at the completion of the trial, the clinical dose needed to achieve remission was compared with the predicted dose needed to achieve remission. Results Among remitters (n=95), there was a strong concordance (Kendall’s τ-b=0.84, P=0.0001; Cohen’s κ=0.82, P=0.0001) between the actual and the predicted dose need to achieve symptom remission, showing high sensitivity (≥85%), specificity (≥86%), and accuracy (≥89%) of the tool. Conclusion Findings provide initial evidence for the clinical validity of a polygene pharmacogenetic-based tool for desvenlafaxine dosing. PMID:27779571

The molecular structural features controlling stickiness in cooked rice, a major palatability determinant

NASA Astrophysics Data System (ADS)

Li, Hongyan; Fitzgerald, Melissa A.; Prakash, Sangeeta; Nicholson, Timothy M.; Gilbert, Robert G.

2017-03-01

The stickiness of cooked rice is important for eating quality and consumer acceptance. The first molecular understanding of stickiness is obtained from leaching and molecular structural characteristics during cooking. Starch is a highly branched glucose polymer. We find (i) the molecular size of leached amylopectin is 30 times smaller than that of native amylopectin while (ii) that of leached amylose is 5 times smaller than that of native amylose, (iii) the chain-length distribution (CLD: the number of monomer units in a chain on the branched polymer) of leached amylopectin is similar to native amylopectin while (iv) the CLD of leached amylose is much narrower than that of the native amylose, and (v) mainly amylopectin, not amylose, leaches out of the granule and rice kernel during cooking. Stickiness is found to increase with decreasing amylose content in the whole grain, and, in the leachate, with increasing total amount of amylopectin, the proportion of short amylopectin chains, and amylopectin molecular size. Molecular adhesion mechanisms are put forward to explain this result. This molecular structural mechanism provides a new tool for rice breeders to select cultivars with desirable palatability by quantifying the components and molecular structure of leached starch.

Molecular Pathogenesis and Diagnostic, Prognostic and Predictive Molecular Markers in Sarcoma.

PubMed

Mariño-Enríquez, Adrián; Bovée, Judith V M G

2016-09-01

Sarcomas are infrequent mesenchymal neoplasms characterized by notable morphological and molecular heterogeneity. Molecular studies in sarcoma provide refinements to morphologic classification, and contribute diagnostic information (frequently), prognostic stratification (rarely) and predict therapeutic response (occasionally). Herein, we summarize the major molecular mechanisms underlying sarcoma pathogenesis and present clinically useful diagnostic, prognostic and predictive molecular markers for sarcoma. Five major molecular alterations are discussed, illustrated with representative sarcoma types, including 1. the presence of chimeric transcription factors, in vascular tumors; 2. abnormal kinase signaling, in gastrointestinal stromal tumor; 3. epigenetic deregulation, in chondrosarcoma, chondroblastoma, and other tumors; 4. deregulated cell survival and proliferation, due to focal copy number alterations, in dedifferentiated liposarcoma; 5. extreme genomic instability, in conventional osteosarcoma as a representative example of sarcomas with highly complex karyotype. Copyright © 2016 Elsevier Inc. All rights reserved.

Major bleeding risks of different low-molecular-weight heparin agents: a cohort study in 12 934 patients treated for acute venous thrombosis.

PubMed

van Rein, N; Biedermann, J S; van der Meer, F J M; Cannegieter, S C; Wiersma, N; Vermaas, H W; Reitsma, P H; Kruip, M J H A; Lijfering, W M

2017-07-01

Essentials Low-molecular-weight-heparins (LMWH) kinetics differ which may result in different bleeding risks. A cohort of 12 934 venous thrombosis patients on LMWH was followed until major bleeding. The absolute major bleeding risk was low among patients registered at the anticoagulation clinic. Once-daily dosing was associated with a lower bleeding risk as compared with twice-daily. Background Low-molecular-weight heparins (LMWHs) are considered members of a class of drugs with similar anticoagulant properties. However, pharmacodynamics and pharmacokinetics between LMWHs differ, which may result in different bleeding risks. As these agents are used by many patients, small differences may lead to a large effect on numbers of major bleeding events. Objectives To determine major bleeding risks for different LMWH agents and dosing schedules. Methods A cohort of acute venous thrombosis patients from four anticoagulation clinics who used an LMWH and a vitamin K antagonist were followed until they ceased LMWH treatment or until major bleeding. Exposures were classified according to different types of LMWHs and for b.i.d. and o.d. use. Cumulative incidences for major bleeding per 1000 patients and risk ratios were calculated and adjusted for study center. Results The study comprised 12 934 patients with a mean age of 59 years; 6218 (48%) were men. The cumulative incidence of major bleeding was 2.5 per 1000 patients (95% confidence interval [CI], 1.7-3.5). Enoxaparin b.i.d. or o.d. was associated with a relative bleeding risk of 1.7 (95% CI, 0.2-17.5) compared with nadroparin o.d. In addition, a nadroparin b.i.d. dosing schedule was associated with a 2.0-fold increased major bleeding risk (95% CI, 0.8-5.1) as compared with a nadroparin o.d. dosing schedule. Conclusions Absolute major bleeding rates were low for all LMWH agents and dosing schedules in a large unselected cohort. Nevertheless, twice-daily dosing with nadroparin appeared to be associated with an increased

Planned Pregnancy in a Chronic Myeloid Leukemia Patient in Molecular Remission

PubMed Central

Pavlovsky, Carolina; Giere, Isabel; Van Thillo, Germán

2012-01-01

Excellent response rates and a good quality of life have been observed since the introduction of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) treatment. Consequently, some challenges began to appear in CML women in child-bearing age wishing to become pregnant. Currently, many women around the world are in stable major/complete molecular response MMR/CMR (MMR: <0.1% BCR-ABL/ABL and CMR: undetectable BCR-ABL mRNA by RQ-PCR transcript levels on the international scale). The condition of stable MMR/CMR is linked to a long-term virtual absence of progression to the accelerated and blastic phase and to the possibility of stopping the TKI treatment with the maintenance of a condition of CMR in a proportion of cases. Imatinib teratogenic and prescribing information prohibits the use of it during pregnancy. We describe the case of a 36-year-old female patient with CML in chronic phase who stopped imatinib after 2 years in major molecular response (MMR) to plan a pregnancy. Molecular monitoring by RQ-PCR was performed quarterly. She achieved a safe pregnancy and delivery maintaining an optimal molecular response throughout the pregnancy. Isolated literature reports have been described, but no formal advice has been described at present time. PMID:22928126

Isolation and identification of molecular species of phosphatidylcholine and lysophosphatidylcholine from jojoba seed meal (Simmondsia chinensis).

PubMed

Léon, Fabian; Van Boven, Maurits; de Witte, Peter; Busson, Roger; Cokelaere, Marnix

2004-03-10

A mixture of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) has been isolated by column chromatography from a jojoba meal (Simmondsia chinensis) extract. The molecular species of both classes could be separated and isolated by C18 reversed phase HPLC. The two major compounds were identified by 1D and 2D (1)H and (13)C NMR, by MS, and by GC-MS as 1-oleoyl-3-lysophosphatidylcholine and 1,2-dioleoyl-3-phosphatidylcholine. Eight other molecular species of LPC and four other molecular species of PC could be assigned by comparison of the mass spectra of the isolated compounds with the spectra of the two major compounds. Complete characterization of the individual molecular species was achieved by GC and GC-MS analysis of the fatty acyl composition from the isolated compounds. The PC/LPC proportion in the phospholipid mixture from three different samples is 1.6 +/- 0.1. LPC is considered to be an important bioactive compound; the results of this study suggest further research for the evaluation of potential health benefits of jojoba meal phospholipids.

Molecular Dissection of a Major Gene Effect on a Quantitative Trait: The Level of Alcohol Dehydrogenase Expression in Drosophila Melanogaster

PubMed Central

Stam, L. F.; Laurie, C. C.

1996-01-01

A molecular mapping experiment shows that a major gene effect on a quantitative trait, the level of alcohol dehydrogenase expression in Drosophila melanogaster, is due to multiple polymorphisms within the Adh gene. These polymorphisms are located in an intron, the coding sequence, and the 3' untranslated region. Because of nonrandom associations among polymorphisms at different sites, the individual effects combine (in some cases epistatically) to produce ``superalleles'' with large effect. These results have implications for the interpretation of major gene effects detected by quantitative trait locus mapping methods. They show that large effects due to a single locus may be due to multiple associated polymorphisms (or sequential fixations in isolated populations) rather than individual mutations of large effect. PMID:8978044

Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.

PubMed

Mahfuz, Mohammad Upal

2016-10-01

In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.

Equilibrium state at supersaturated drug concentration achieved by hydroxypropyl methylcellulose acetate succinate: molecular characterization using (1)H NMR technique.

PubMed

Ueda, Keisuke; Higashi, Kenjirou; Yamamoto, Keiji; Moribe, Kunikazu

2015-04-06

The maintenance mechanism of the supersaturated state of poorly water-soluble drugs, glibenclamide (GLB) and chlorthalidone (CLT), in hydroxypropyl methylcellulose acetate succinate (HPMC-AS) solution was investigated at a molecular level. HPMC-AS suppressed drug crystallization from supersaturated drug solution and maintained high supersaturated level of drugs with small amount of HPMC-AS for 24 h. However, the dissolution of crystalline GLB into HPMC-AS solution failed to produce supersaturated concentrations, although supersaturated concentrations were achieved by adding amorphous GLB to HPMC-AS solution. HPMC-AS did not improve drug dissolution and/or solubility but efficiently inhibited drug crystallization from supersaturated drug solutions. Such an inhibiting effect led to the long-term maintenance of the amorphous state of GLB in HPMC-AS solution. NMR measurements showed that HPMC-AS suppressed the molecular mobility of CLT depending on their supersaturation level. Highly supersaturated CLT in HPMC-AS solution formed a gel-like structure with HPMC-AS in which the molecular mobility of the CLT was strongly suppressed. The gel-like structure of HPMC-AS could inhibit the reorganization from drug prenuclear aggregates to the crystal nuclei and delay the formation of drug crystals. The prolongation subsequently led to the redissolution of the aggregated drugs in aqueous solution and formed the equilibrium state at the supersaturated drug concentration in HPMC-AS solution. The equilibrium state formation of supersaturated drugs by HPMC-AS should be an essential mechanism underlying the marked drug concentration improvement.

Sampling Molecular Conformers in Solution with Quantum Mechanical Accuracy at a Nearly Molecular-Mechanics Cost.

PubMed

Rosa, Marta; Micciarelli, Marco; Laio, Alessandro; Baroni, Stefano

2016-09-13

We introduce a method to evaluate the relative populations of different conformers of molecular species in solution, aiming at quantum mechanical accuracy, while keeping the computational cost at a nearly molecular-mechanics level. This goal is achieved by combining long classical molecular-dynamics simulations to sample the free-energy landscape of the system, advanced clustering techniques to identify the most relevant conformers, and thermodynamic perturbation theory to correct the resulting populations, using quantum-mechanical energies from density functional theory. A quantitative criterion for assessing the accuracy thus achieved is proposed. The resulting methodology is demonstrated in the specific case of cyanin (cyanidin-3-glucoside) in water solution.

Reviewing and Updating the Major Molecular Markers for Stem Cells

PubMed Central

Calloni, Raquel; Cordero, Elvira Alicia Aparicio; Henriques, João Antonio Pêgas

2013-01-01

Stem cells (SC) are able to self-renew and to differentiate into many types of committed cells, making SCs interesting for cellular therapy. However, the pool of SCs in vivo and in vitro consists of a mix of cells at several stages of differentiation, making it difficult to obtain a homogeneous population of SCs for research. Therefore, it is important to isolate and characterize unambiguous molecular markers that can be applied to SCs. Here, we review classical and new candidate molecular markers that have been established to show a molecular profile for human embryonic stem cells (hESCs), mesenchymal stem cells (MSCs), and hematopoietic stem cells (HSCs). The commonly cited markers for embryonic ESCs are Nanog, Oct-4, Sox-2, Rex-1, Dnmt3b, Lin-28, Tdgf1, FoxD3, Tert, Utf-1, Gal, Cx43, Gdf3, Gtcm1, Terf1, Terf2, Lefty A, and Lefty B. MSCs are primarily identified by the expression of CD13, CD29, CD44, CD49e, CD54, CD71, CD73, CD90, CD105, CD106, CD166, and HLA-ABC and lack CD14, CD31, CD34, CD45, CD62E, CD62L, CD62P, and HLA-DR expression. HSCs are mainly isolated based on the expression of CD34, but the combination of this marker with CD133 and CD90, together with a lack of CD38 and other lineage markers, provides the most homogeneous pool of SCs. Here, we present new and alternative markers for SCs, along with microRNA profiles, for these cells. PMID:23336433

Reference materials for molecular diagnostics: Current achievements and future strategies.

PubMed

Jing, Rongrong; Wang, Huimin; Ju, Shaoqing; Cui, Ming

2018-06-01

Molecular diagnoses have become more widespread in many areas of laboratory medicine where qualitative or quantitative approaches are used to detect nucleic acids. The increasing number of assay methods and the targets for molecular diagnostics contribute to variability in the test results among clinical laboratories. Thus, reference materials (RMs) are required to enhance the comparability of results. This review focuses on the definition of RMs as well as the production and characteristics of higher order RMs from different organizations and their future strategies. We describe the recent progress in RMs, including the definition of RMs by the Joint Committee for Guides in Metrology, as well as the production and characteristics of higher order RMs by international official bodies. There is an urgent need for RMs in nucleic acid testing, especially higher order RMs. To advance the harmonization and standardization of clinical nucleic acid detection, cooperation between the above organizations is proposed and different approaches to higher order RMs development are also needed. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Investigation of Writing Strategies, Writing Apprehension, and Writing Achievement among Saudi EFL-Major Students

ERIC Educational Resources Information Center

Al Asmari, AbdulRahman

2013-01-01

The tenet of this study is to investigate the use of writing strategies in reducing writing apprehension and uncovering its effect on EFL students' writing achievement. It also attempts to explore associations between foreign language apprehension, writing achievement and writing strategies. The primary aims of the study were to explore the…

Motivation Orientations, Academic Achievement, and Career Goals of Undergraduate Music Education Majors

ERIC Educational Resources Information Center

Schmidt, Charles P.; Zdzinski, Stephen F.; Ballard, Dennis L.

2006-01-01

This study is an examination of motivation orientations (mastery, intrinsic, cooperative, individual, competition, ego, approach success, avoid failure, hypercompetition, personal development competition) and musical self-concept in relation to measures of academic achievement and career goals of preservice music teachers. The research questions…

Molecular mechanisms of inflammation and tissue injury after major trauma-is complement the "bad guy"?

PubMed Central

2011-01-01

Trauma represents the leading cause of death among young people in industrialized countries. Recent clinical and experimental studies have brought increasing evidence for activation of the innate immune system in contributing to the pathogenesis of trauma-induced sequelae and adverse outcome. As the "first line of defense", the complement system represents a potent effector arm of innate immunity, and has been implicated in mediating the early posttraumatic inflammatory response. Despite its generic beneficial functions, including pathogen elimination and immediate response to danger signals, complement activation may exert detrimental effects after trauma, in terms of mounting an "innocent bystander" attack on host tissue. Posttraumatic ischemia/reperfusion injuries represent the classic entity of complement-mediated tissue damage, adding to the "antigenic load" by exacerbation of local and systemic inflammation and release of toxic mediators. These pathophysiological sequelae have been shown to sustain the systemic inflammatory response syndrome after major trauma, and can ultimately contribute to remote organ injury and death. Numerous experimental models have been designed in recent years with the aim of mimicking the inflammatory reaction after trauma and to allow the testing of new pharmacological approaches, including the emergent concept of site-targeted complement inhibition. The present review provides an overview on the current understanding of the cellular and molecular mechanisms of complement activation after major trauma, with an emphasis of emerging therapeutic concepts which may provide the rationale for a "bench-to-bedside" approach in the design of future pharmacological strategies. PMID:22129197

An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen.

PubMed

Bonnet, B; Messaoudi, K; Jacomet, F; Michaud, E; Fauquert, J L; Caillaud, D; Evrard, B

2018-01-01

Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals. Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends.

Counterstereotypic Identity among High-Achieving Black Students

ERIC Educational Resources Information Center

Harpalani, Vinay

2017-01-01

This article examines how racial stereotypes affect achievement and identity formation among low income, urban Black adolescents. Specifically, the major question addressed is: how do high-achieving Black students succeed academically despite negative stereotypes of their intellectual abilities? Results indicate that high-achieving Black youth,…

Testing a Model of the Relationship of Demographic, Affective, and Fitness Variables to Academic Achievement among Non-Science Majors at an Independent University

NASA Astrophysics Data System (ADS)

Dutra, Andrew Martin

The purpose of this study was to determine the relationship of specific attributes of college students to their academic achievement at an independent university in central Florida. Academic achievement was measured as the numeric score on the final exam in a survey-of-science course (EDS 1032) required for non-science majors. Attribute sets included personological, affective, and fitness variables. A hypothesized diagram of the direct and indirect effects among these attributes relative to academic achievement was developed and tested using data collected Spring 2014 from 168 students in four sections of EDS 1032 at Florida Institute of Technology. Multiple regression results revealed that 19% of the variance in a students' academic achievement was due to the influence of these three sets of research factors; this was found to be statistically significant. The results of mediation analyses also indicated that three variables had significant direct effects on academic achievement, namely gender, number of academic credits, and sports motivation. In addition, gender had a significant indirect effect on academic achievement via stress, and the number of academic credits had a significant indirect effect on academic achievement via sports motivation. These findings indicated that female students scored roughly six points higher than male students on this final exam. Also, gender's influence on academic achievement was partially attributable to the student's level of stress (e.g., male students with high levels of stress had lower grades on this final exam than female students with the same level of stress). In addition, it was found that students taking more academic credits were likely to score higher on this final exam than those students taking fewer credits. Further, as students' level of sports amotivation increased, the strength of the relationship between the number of student academic credits and academic achievement decreased. These results support Self

Some Dynamical Features of Molecular Fragmentation by Electrons and Swift Ions

NASA Astrophysics Data System (ADS)

Montenegro, E. C.; Sigaud, L.; Wolff, W.; Luna, H.; Natalia, Ferreira

To date, the large majority of studies on molecular fragmentation by swift charged particles have been carried out using simple molecules, for which reliable Potential Energy Curves are available to interpret the measured fragmentation yields. For complex molecules the scenario is quite different and such guidance is not available, obscuring even a simple organization of the data which are currently obtained for a large variety of molecules of biological or technological interest. In this work we show that a general and relatively simple methodology can be used to obtain a broader picture of the fragmentation pattern of an arbitrary molecule. The electronic ionization or excitation cross section of a given molecular orbital, which is the first part of the fragmentation process, can be well scaled by a simple and general procedure at high projectile velocities. The fragmentation fractions arising from each molecular orbital can then be achieved by matching the calculated ionization with the measured fragmentation cross sections. Examples for Oxygen, Chlorodifluoromethane and Pyrimidine molecules are presented.

Structure of Black Male Students Academic Achievement in Science

NASA Astrophysics Data System (ADS)

Rascoe, Barbara

Educational policies and practices have been largely unsuccessful in closing the achievement gap between Black and White students "Schwartz, 2001". This achievement gap is especially problematic for Black students in science "Maton, Hrabrowski, - Schmitt, 2000. Given the fact that the Black-White achievement gap is still an enigma, the purpose of this article is to address the Black female-Black male academic achievement gap in science majors. Addressing barriers that Black male students may experience as college science and engineering majors, this article presents marketing strategies relative to politics, emotional intelligence, and issues with respect to how science teaching, and Black male students' responses to it, are different. Many Black male students may need to experience a paradigm shift, which structures and enhances their science achievement. Paradigm shifts are necessary because exceptional academic ability and motivation are not enough to get Black males from their first year in a science, technology, education, and mathematics "STEM" major to a bachelor's degree in science and engineering. The conclusions focus on the balance of truth-slippery slopes concerning the confluence of science teachers' further ado and Black male students' theories, methods, and values that position their academic achievement in science and engineering majors.

Stereotype Threat's Effect on Women's Achievement in Chemistry: The Interaction of Achievement Goal Orientation for Women in Science Majors

ERIC Educational Resources Information Center

Conway-Klaassen, Janice Marjorie

2010-01-01

"Stereotype threat is being at risk of confirming, as a self-characteristic, a negative stereotype about one's group" (C. M. Steele & Aronson, 1995, p. 797). A stereotype threat effect then is described as the detrimental impact on a person's performance or achievement measurements when they are placed in a stereotype threat environment. For…

The molecular refractive function of lens γ-crystallins

PubMed Central

Zhao, Huaying; Brown, Patrick H.; Magone, M. Teresa; Schuck, Peter

2011-01-01

γ-crystallins constitute the major protein component in the nucleus of the vertebrate eye lens. Present at very high concentrations, they exhibit extreme solubility and thermodynamic stability to prevent scattering of light and the formation of cataracts. However, functions beyond this structural role have remained mostly unclear. Here, we calculate molecular refractive index increments of crystallins. We show that all lens γ-crystallins have evolved a significantly elevated molecular refractive index increment, which is far above those of most proteins, including non-lens members of the βγ-crystallin family from different species. The same trait has evolved in parallel in crystallins of different phyla, including in the S-crystallins of cephalopods. A high refractive index increment can lower the crystallin concentration required to achieve a suitable refractive power of the lens, and thereby reduce their propensity to aggregate and form cataract. To produce a significant increase of the refractive index increment, a substantial global shift in the amino acid composition is required, which can naturally explain the highly unusual amino acid composition of γ-crystallins and their functional homologues. This function provides a new perspective for interpreting their molecular structure. PMID:21684289

The molecular refractive function of lens γ-Crystallins.

PubMed

Zhao, Huaying; Brown, Patrick H; Magone, M Teresa; Schuck, Peter

2011-08-19

γ-Crystallins constitute the major protein component in the nucleus of the vertebrate eye lens. Present at very high concentrations, they exhibit extreme solubility and thermodynamic stability to prevent scattering of light and formation of cataracts. However, functions beyond this structural role have remained mostly unclear. Here, we calculate molecular refractive index increments of crystallins. We show that all lens γ-crystallins have evolved a significantly elevated molecular refractive index increment, which is far above those of most proteins, including nonlens members of the βγ-crystallin family from different species. The same trait has evolved in parallel in crystallins of different phyla, including S-crystallins of cephalopods. A high refractive index increment can lower the crystallin concentration required to achieve a suitable refractive power of the lens and thereby reduce their propensity to aggregate and form cataracts. To produce a significant increase in the refractive index increment, a substantial global shift in amino acid composition is required, which can naturally explain the highly unusual amino acid composition of γ-crystallins and their functional homologues. This function provides a new perspective for interpreting their molecular structure. Copyright © 2011. Published by Elsevier Ltd.

Porphyrin-sensitized solar cells: systematic molecular optimization, coadsorption and cosensitization.

PubMed

Song, Heli; Liu, Qingyun; Xie, Yongshu

2018-02-15

As a promising low-cost solar energy conversion technique, dye-sensitized solar cells have undergone spectacular development since 1991. For practical applications, improvement of power conversion efficiency has always been one of the major research topics. Porphyrins are outstanding sensitizers endowed with strong sunlight harvesting ability in the visible region and multiple reaction sites available for functionalization. However, judicious molecular design in consideration of light-harvest, energy levels, operational dynamics, adsorption geometry and suppression of back reactions is specifically required for achieving excellent photovoltaic performance. This feature article highlights some of the recently developed porphyrin sensitizers, especially focusing on the systematic dye structure optimization approach in combination with coadsorption and cosensitization methods in pursuing higher efficiencies. Herein, we expect to provide more insights into the structure-performance correlation and molecular engineering strategies in a stepwise manner.

Mathematics anxiety and mathematics achievement

NASA Astrophysics Data System (ADS)

Sherman, Brian F.; Wither (Post.), David P.

2003-09-01

This paper is a distillation of the major result from the 1998 Ph.D. thesis of the late David Wither. It details a longitudinal study over five years of the relationship between mathematics anxiety and mathematics achievement. It starts from the already well documented negative correlation between the two, and seeks to establish one of the three hypotheses—that mathematics anxiety causes an impairment of mathematics achievement; that lack of mathematics achievement causes mathematics anxiety; or that there is a third underlying cause of the two.

Three pillars for achieving quantum mechanical molecular dynamics simulations of huge systems: Divide-and-conquer, density-functional tight-binding, and massively parallel computation.

PubMed

Nishizawa, Hiroaki; Nishimura, Yoshifumi; Kobayashi, Masato; Irle, Stephan; Nakai, Hiromi

2016-08-05

The linear-scaling divide-and-conquer (DC) quantum chemical methodology is applied to the density-functional tight-binding (DFTB) theory to develop a massively parallel program that achieves on-the-fly molecular reaction dynamics simulations of huge systems from scratch. The functions to perform large scale geometry optimization and molecular dynamics with DC-DFTB potential energy surface are implemented to the program called DC-DFTB-K. A novel interpolation-based algorithm is developed for parallelizing the determination of the Fermi level in the DC method. The performance of the DC-DFTB-K program is assessed using a laboratory computer and the K computer. Numerical tests show the high efficiency of the DC-DFTB-K program, a single-point energy gradient calculation of a one-million-atom system is completed within 60 s using 7290 nodes of the K computer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The effect of active learning on college students' achievement, motivation, and self-efficacy in a human physiology course for non-majors

NASA Astrophysics Data System (ADS)

Wilke, Roger Russell

2000-10-01

This study investigated the effects active learning strategies had on college students' achievement, motivation, and self-efficacy, in a human physiology course for non-majors. A continuum-based active learning instructional model was implemented over the course of a semester to assess the effects on the variables and specific student outcomes of learning mentioned above. In addition analyses were conducted to explore what learner characteristics contributed to the successful implementation of the model such as students' gender, classification, major, grade point average, ACT and SAT scores, motivation, and self-efficacy. A quasi-experimental, Solomon-4 Group design was undertaken on 171 students in a small west-Texas university. Treatment groups were taught using the model while controls were taught using traditional lecture methods. Students were administered a comprehensive physiology content exam, sections of the Motivated Strategies for Learning Questionnaire, and attitude surveys to assess the effects of the continuum-based active learning strategies. Factorial analyses indicated the treatment group acquired significantly more content knowledge and were significantly more self-efficacious than students in the control group. There were no significant differences in motivation. Factorial and modified regression analyses in the aptitude by treatment interaction exploration determined that males in the treatment group performed significantly better on the comprehensive physiology content exam versus males in the control group. While females performed better overall than males, there were no significant differences in achievement between females in the treatment group and those in the control. No significant interactions were found for the other learner characteristics. The results also indicated that students' general cognitive ability as measured by their grade point average, ACT, and SAT scores and their self-efficacy contributed significantly to their

Will Flexible Learning Raise Student Achievement?

ERIC Educational Resources Information Center

Guest, Ross

2005-01-01

This paper presents both theoretical and survey evidence on the effect of flexible learning--in particular, the shift to a more student-centred approach to learning--on academic achievement by students. A survey was conducted of 577 business students at a major Australian university in order to elicit their preferences for academic achievement and…

[Non-small cell lung cancer. Subtyping and predictive molecular marker investigations in cytology].

PubMed

Savic, S; Bihl, M P; Bubendorf, L

2012-07-01

The diagnosis and treatment of non-small cell lung cancer (NSCLC) have been revolutionized over the last few years. Requirements for cytopathologists in lung cancer diagnosis have therefore changed. The general diagnostic category of NSLC is no longer sufficient. In addition cytological specimens need to be evaluated for adequacy regarding predictive marker analyses. Accurate NSCLC subtyping with a distinction of adenocarcinoma from squamous cell carcinoma is crucial for treatment decisions as the subtype will decide on the chemotherapy regimen and the choice of predictive marker analyses for targeted treatment. In the majority of cases, the subtype can be diagnosed by morphology alone. Cytology is equally well suited as biopsy specimens for the assessment of molecular predictive markers. The best results are achieved when both cytology and biopsy specimens are compared to choose the most appropriate specimen for morphological subtyping and molecular testing. In this paper, we discuss special issues of NSCLC subtyping and currently recommended predictive molecular marker analyses.

Dealing with the Challenges of Teaching Molecular Biophysics to Biochemistry Majors through an Heuristics-Based Approach

ERIC Educational Resources Information Center

Castanho, Miguel A. R. B.

2002-01-01

The main distinction between the overlapping fields of molecular biophysics and biochemistry resides in their different approaches to the same problems. Molecular biophysics makes more use of physical techniques and focuses on quantitative data. This difference encounters two difficult pedagogical challenges when teaching molecular biophysics to…

Nuclear transformation of eukaryotic microalgae: historical overview, achievements and problems.

PubMed

León, Rosa; Fernández, Emilio

2007-01-01

Transformation of microalgae is a first step in their use for biotechnological applications involving foreign protein production or molecular modifications of specific cell metabolic pathways. Since the first reliable achievements of nuclear transformation in Chlamydomonas, other eukaryotic microalgae have become transformed with molecular markers that allow a direct selection. Different methods--glass beads, electroporation, particle bombardment, or Agrobacterium--and constructions have been set up in several organisms and successfully used. However, some problems associated with efficiency, integration, or stability of the transgenes still persist and are analysed herein. Though the number of microalgae species successfully transformed is not very high, prospects for transformation of many more are good enough on the basis of what has been achieved so far.

[Plant physiological and molecular biological mechanism in response to aluminium toxicity].

PubMed

Liu, Qiang; Zheng, Shaojian; Lin, Xianyong

2004-09-01

Aluminium toxicity is the major factor limiting crop growth on acid soils, which greatly affects the crop productivity on about 40% cultivated soils of the world and 21% of China. In the past decades, a lot of researches on aluminium toxicity and resistant mechanisms have been doing, and great progress was achieved. This paper dealt with the genetic differences in aluminium tolerance among plants, screening and selecting methods and technologies for identifying aluminium resistance in plants, and physiological and molecular mechanism resistance to aluminium toxicity. Some aspects needed to be further studied were also briefly discussed.

Interventional Molecular Imaging.

PubMed

Solomon, Stephen B; Cornelis, Francois

2016-04-01

Although molecular imaging has had a dramatic impact on diagnostic imaging, it has only recently begun to be integrated into interventional procedures. Its significant impact is attributed to its ability to provide noninvasive, physiologic information that supplements conventional morphologic imaging. The four major interventional opportunities for molecular imaging are, first, to provide guidance to localize a target; second, to provide tissue analysis to confirm that the target has been reached; third, to provide in-room, posttherapy assessment; and fourth, to deliver targeted therapeutics. With improved understanding and application of(18)F-FDG, as well as the addition of new molecular probes beyond(18)F-FDG, the future holds significant promise for the expansion of molecular imaging into the realm of interventional procedures. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Natural Korean Medicine Dang-Gui: Biosynthesis, Effective Extraction and Formulations of Major Active Pyranocoumarins, Their Molecular Action Mechanism in Cancer, and Other Biological Activities.

PubMed

Reddy, Chinreddy Subramanyam; Kim, Seong Cheol; Hur, Mok; Kim, Yeon Bok; Park, Chun Geon; Lee, Woo Moon; Jang, Jae Ki; Koo, Sung Cheol

2017-12-07

Angelica gigas Nakai (AGN) is a crucial oriental medicinal herb that grows especially in Korea and the Far-East countries. It contains chemically active compounds like pyranocoumarins, polyacetylenes and essential oils, which might be useful for treatment of several chronic diseases. It has been used for centuries as a traditional medicine in Southeast Asia, but in Western countries is used as a functional food and a major ingredient of several herbal products. The genus Angelica is also known as 'female ginseng' due to its critical therapeutic role in female afflictions, such as gynecological problems. However, it is well-documented that the AGN pyranocoumarins may play vital beneficial roles against cancer, neurodisorders, inflammation, osteoporosis, amnesia, allergies, depression, fungi, diabetes, ischemia, dermatitis, reactive oxygen species (ROS) and androgen. Though numerous studies revealed the role of AGN pyranocoumarins as therapeutic agents, none of the reviews have published their molecular mechanism of action. To the best of our knowledge, this would be the first review that aims to appraise the biosynthesis of AGN's major active pyranocoumarins, discuss effective extraction and formulation methods, and detail the molecular action mechanism of decursin (D), decursinol angelate (DA) and decursinol (DOH) in chronic diseases, which would further help extension of research in this area.

Integrated Molecular Characterization of Testicular Germ Cell Tumors.

PubMed

Shen, Hui; Shih, Juliann; Hollern, Daniel P; Wang, Linghua; Bowlby, Reanne; Tickoo, Satish K; Thorsson, Vésteinn; Mungall, Andrew J; Newton, Yulia; Hegde, Apurva M; Armenia, Joshua; Sánchez-Vega, Francisco; Pluta, John; Pyle, Louise C; Mehra, Rohit; Reuter, Victor E; Godoy, Guilherme; Jones, Jeffrey; Shelley, Carl S; Feldman, Darren R; Vidal, Daniel O; Lessel, Davor; Kulis, Tomislav; Cárcano, Flavio M; Leraas, Kristen M; Lichtenberg, Tara M; Brooks, Denise; Cherniack, Andrew D; Cho, Juok; Heiman, David I; Kasaian, Katayoon; Liu, Minwei; Noble, Michael S; Xi, Liu; Zhang, Hailei; Zhou, Wanding; ZenKlusen, Jean C; Hutter, Carolyn M; Felau, Ina; Zhang, Jiashan; Schultz, Nikolaus; Getz, Gad; Meyerson, Matthew; Stuart, Joshua M; Akbani, Rehan; Wheeler, David A; Laird, Peter W; Nathanson, Katherine L; Cortessis, Victoria K; Hoadley, Katherine A

2018-06-12

We studied 137 primary testicular germ cell tumors (TGCTs) using high-dimensional assays of genomic, epigenomic, transcriptomic, and proteomic features. These tumors exhibited high aneuploidy and a paucity of somatic mutations. Somatic mutation of only three genes achieved significance-KIT, KRAS, and NRAS-exclusively in samples with seminoma components. Integrated analyses identified distinct molecular patterns that characterized the major recognized histologic subtypes of TGCT: seminoma, embryonal carcinoma, yolk sac tumor, and teratoma. Striking differences in global DNA methylation and microRNA expression between histology subtypes highlight a likely role of epigenomic processes in determining histologic fates in TGCTs. We also identified a subset of pure seminomas defined by KIT mutations, increased immune infiltration, globally demethylated DNA, and decreased KRAS copy number. We report potential biomarkers for risk stratification, such as miRNA specifically expressed in teratoma, and others with molecular diagnostic potential, such as CpH (CpA/CpC/CpT) methylation identifying embryonal carcinomas. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Crystallization and preliminary X-ray analysis of Leishmania major glyoxalase I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ariza, Antonio; Vickers, Tim J.; Greig, Neil

2005-08-01

The detoxification enzyme glyoxalase I from L. major has been crystallized. Preliminary molecular-replacement calculations indicate the presence of three glyoxalase I dimers in the asymmetric unit. Glyoxalase I (GLO1) is a putative drug target for trypanosomatids, which are pathogenic protozoa that include the causative agents of leishmaniasis. Significant sequence and functional differences between Leishmania major and human GLO1 suggest that it may make a suitable template for rational inhibitor design. L. major GLO1 was crystallized in two forms: the first is extremely disordered and does not diffract, while the second, an orthorhombic form, produces diffraction to 2.0 Å. Molecular-replacement calculationsmore » indicate that there are three GLO1 dimers in the asymmetric unit, which take up a helical arrangement with their molecular dyads arranged approximately perpendicular to the c axis. Further analysis of these data are under way.« less

Inequalities in non-communicable diseases between the major population groups in Israel: achievements and challenges.

PubMed

Muhsen, Khitam; Green, Manfred S; Soskolne, Varda; Neumark, Yehuda

2017-06-24

Israel is a high-income country with an advanced health system and universal health-care insurance. Overall, the health status has improved steadily over recent decades. We examined differences in morbidity, mortality, and risk factors for selected non-communicable diseases (NCDs) between subpopulation groups. Between 1975 and 2014, life expectancy in Israel steadily increased and is currently above the average life expectancy for the Organisation for Economic Co-operation and Development countries. Nevertheless, life expectancy has remained lower among Israeli Arabs than Israeli Jews, and this gap has recently widened. Age-adjusted mortality as a result of heart disease, stroke, or diabetes remains higher in Arabs, whereas age-adjusted incidence and mortality of cancer were higher among Jews. The prevalence of obesity and low physical activity in Israel is considerably higher among Arabs than Jews. Smoking prevalence is highest for Arab men and lowest for Arab women. Health inequalities are also evident by the indicators of socioeconomic position and in subpopulations, such as immigrants from the former Soviet Union, ultra-Orthodox Jews, and Bedouin Arabs. Despite universal health coverage and substantial improvements in the overall health of the Israeli population, substantial inequalities in NCDs persist. These differences might be explained, at least in part, by gaps in social determinants of health. The Ministry of Health has developed comprehensive programmes to reduce these inequalities between the major population groups. Sustained coordinated multisectoral efforts are needed to achieve a greater impact and to address other social inequalities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular Mapping of Flowering Time Major Genes and QTLs in Chickpea (Cicer arietinum L.)

PubMed Central

Mallikarjuna, Bingi P.; Samineni, Srinivasan; Thudi, Mahendar; Sajja, Sobhan B.; Khan, Aamir W.; Patil, Ayyanagowda; Viswanatha, Kannalli P.; Varshney, Rajeev K.; Gaur, Pooran M.

2017-01-01

Flowering time is an important trait for adaptation and productivity of chickpea in the arid and the semi-arid environments. This study was conducted for molecular mapping of genes/quantitative trait loci (QTLs) controlling flowering time in chickpea using F2 populations derived from four crosses (ICCV 96029 × CDC Frontier, ICC 5810 × CDC Frontier, BGD 132 × CDC Frontier and ICC 16641 × CDC Frontier). Genetic studies revealed monogenic control of flowering time in the crosses ICCV 96029 × CDC Frontier, BGD 132 × CDC Frontier and ICC 16641 × CDC Frontier, while digenic control with complementary gene action in ICC 5810 × CDC Frontier. The intraspecific genetic maps developed from these crosses consisted 75, 75, 68 and 67 markers spanning 248.8 cM, 331.4 cM, 311.1 cM and 385.1 cM, respectively. A consensus map spanning 363.8 cM with 109 loci was constructed by integrating four genetic maps. Major QTLs corresponding to flowering time genes efl-1 from ICCV 96029, efl-3 from BGD 132 and efl-4 from ICC 16641 were mapped on CaLG04, CaLG08 and CaLG06, respectively. The QTLs and linked markers identified in this study can be used in marker-assisted breeding for developing early maturing chickpea. PMID:28729871

Molecular-Scale Electronics: From Concept to Function.

PubMed

Xiang, Dong; Wang, Xiaolong; Jia, Chuancheng; Lee, Takhee; Guo, Xuefeng

2016-04-13

Creating functional electrical circuits using individual or ensemble molecules, often termed as "molecular-scale electronics", not only meets the increasing technical demands of the miniaturization of traditional Si-based electronic devices, but also provides an ideal window of exploring the intrinsic properties of materials at the molecular level. This Review covers the major advances with the most general applicability and emphasizes new insights into the development of efficient platform methodologies for building reliable molecular electronic devices with desired functionalities through the combination of programmed bottom-up self-assembly and sophisticated top-down device fabrication. First, we summarize a number of different approaches of forming molecular-scale junctions and discuss various experimental techniques for examining these nanoscale circuits in details. We then give a full introduction of characterization techniques and theoretical simulations for molecular electronics. Third, we highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits. Finally, we provide a critical discussion of limitations and main challenges that still exist for the development of molecular electronics. These analyses should be valuable for deeply understanding charge transport through molecular junctions, the device fabrication process, and the roadmap for future practical molecular electronics.

Molecular cloning and characterization of an α-amylase cDNA highly expressed in major feeding stages of the coffee berry borer, Hypothenemus hampei.

PubMed

Bezerra, C A; Macedo, L L P; Amorim, T M L; Santos, V O; Fragoso, R R; Lucena, W A; Meneguim, A M; Valencia-Jimenez, A; Engler, G; Silva, M C M; Albuquerque, E V S; Grossi-de-Sa, M F

2014-12-10

α-Amylases are common enzymes responsible for hydrolyzing starch. Insect-pests, whose larvae develop in seeds, rely obligatorily on α-amylase activity to digest starch, as their major food source. Considering the relevance of insect α-amylases and the natural α-amylase inhibitors present in seeds to protect from insect damage, we report here the molecular cloning and nucleotide sequence of the full-length AmyHha cDNA of the coffee berry borer, Hypothenemus hampei, a major insect-pest of coffee crops. The AmyHha sequence has 1879 bp, containing a 1458 bp open reading frame, which encodes a predicted protein with 485 amino acid residues, with a predicted molecular mass of 51.2 kDa. The deduced protein showed 55-79% identity to other insect α-amylases, including Anthonomus grandis, Ips typographus and Sitophilus oryzae α-amylases. In depth analysis revealed that the highly conserved three amino acid residues (Asp184, Glu220, and Asp285), which compose the catalytic site are also presented in AmyHha amylase. The AmyHha gene seems to be a single copy in the haploid genome and AmyHha transcription levels were found higher in L2 larvae and adult insects, both corresponding to major feeding phases. Modeling of the AmyHha predicted protein uncovered striking structural similarities to the Tenebrio molitor α-amylase also displaying the same amino acid residues involved in enzyme catalysis (Asp184, Glu220 and Asp285). Since AmyHha gene was mostly transcribed in the intestinal tract of H. hampei larvae, the cognate α-amylase could be considered a high valuable target to coffee bean insect control by biotechnological strategies. Copyright © 2014. Published by Elsevier B.V.

Regulation of assimilate import into sink organs: update on molecular drivers of sink strength

PubMed Central

Bihmidine, Saadia; Hunter, Charles T.; Johns, Christine E.; Koch, Karen E.; Braun, David M.

2013-01-01

Recent developments have altered our view of molecular mechanisms that determine sink strength, defined here as the capacity of non-photosynthetic structures to compete for import of photoassimilates. We review new findings from diverse systems, including stems, seeds, flowers, and fruits. An important advance has been the identification of new transporters and facilitators with major roles in the accumulation and equilibration of sugars at a cellular level. Exactly where each exerts its effect varies among systems. Sugarcane and sweet sorghum stems, for example, both accumulate high levels of sucrose, but may do so via different paths. The distinction is central to strategies for targeted manipulation of sink strength using transporter genes, and shows the importance of system-specific analyses. Another major advance has been the identification of deep hypoxia as a feature of normal grain development. This means that molecular drivers of sink strength in endosperm operate in very low oxygen levels, and under metabolic conditions quite different than previously assumed. Successful enhancement of sink strength has nonetheless been achieved in grains by up-regulating genes for starch biosynthesis. Additionally, our understanding of sink strength is enhanced by awareness of the dual roles played by invertases (INVs), not only in sucrose metabolism, but also in production of the hexose sugar signals that regulate cell cycle and cell division programs. These contributions of INV to cell expansion and division prove to be vital for establishment of young sinks ranging from flowers to fruit. Since INV genes are themselves sugar-responsive “feast genes,” they can mediate a feed-forward enhancement of sink strength when assimilates are abundant. Greater overall productivity and yield have thus been attained in key instances, indicating that even broader enhancements may be achievable as we discover the detailed molecular mechanisms that drive sink strength in diverse

First microscopical and molecular-based characterization of Leishmania major within naturally infected Phlebotomus salehi (Diptera; Psychodidae) in Fars province, southern Iran

PubMed Central

DAVAMI, M H; MOTAZEDIAN, M H; KALANTARI, M; ASGARI, Q; BADZOHRE, A; MOHAMMADPOUR, I

2011-01-01

Zoonotoc cutaneous leishmaniasis is endemic in several parts of Iran. Jahrom district is one of the most important endemic foci of leishmaniasis located in Fars province, southern Iran. To identify the vectors of leishmaniasis in this area, a total of 349 sandflies were collected during May to August 2009. They were caught from outdoors in five regions of Jahrom district including villages of Mousavieh, Ghotb-Abad, Heydar-Abad, Fath-Abad and Jahrom County. Eleven species of Phlebotomine (three Phlebotomus spp. and eight Sergentomyia spp.) were detected. To determine the sandflies naturally infected by Leishmania spp., 122 female sandflies were dissected and evaluated microscopically using Giemsa-stained slides. Natural infection of 2 out of 38 (5.26%) P. papatasi and 1 out of 8 (12.5%) P. salehi to Leishmania major was confirmed in the region. Sequencing and nested polymerase chain reaction-based detection of Leishmania were carried out to confirm the microscopic findings. Five (13.16%) P. papatasi and two (25%) P. salehi were positive in nested polymerase chain reaction assay. All positive samples were shown 72–76% similarity with L. major Friedlin. On the basis of our knowledge, this is the first molecular detection of L. major within naturally infected P. salehi in this region in southern Iran. PMID:22185942

Molecular anions.

PubMed

Simons, Jack

2008-07-24

The experimental and theoretical study of molecular anions has undergone explosive growth over the past 40 years. Advances in techniques used to generate anions in appreciable numbers as well as new ion-storage, ion-optics, and laser spectroscopic tools have been key on the experimental front. Theoretical developments on the electronic structure and molecular dynamics fronts now allow one to achieve higher accuracy and to study electronically metastable states, thus bringing theory in close collaboration with experiment in this field. In this article, many of the experimental and theoretical challenges specific to studying molecular anions are discussed. Results from many research groups on several classes of molecular anions are overviewed, and both literature citations and active (in online html and pdf versions) links to numerous contributing scientists' Web sites are provided. Specific focus is made on the following families of anions: dipole-bound, zwitterion-bound, double-Rydberg, multiply charged, metastable, cluster-based, and biological anions. In discussing each kind of anion, emphasis is placed on the structural, energetic, spectroscopic, and chemical-reactivity characteristics that make these anions novel, interesting, and important.

New insights into molecular diagnostic pathology of primary liver cancer: Advances and challenges.

PubMed

Cong, Wen-Ming; Wu, Meng-Chao

2015-11-01

Primary liver cancer (PLC) is one of the most common malignancies worldwide with increasing incidence and accounts for the third leading cause of cancer-related mortality. Traditional morphopathology primarily emphasizes qualitative diagnosis of PLC, which is not sufficient to resolve the major concern of increasing the long-term treatment efficacy of PLC in clinical management for the modern era. Since the beginning of the 21st century, molecular pathology has played an active role in the investigation of the evaluation of the metastatic potential of PLC, detection of drug targets, prediction of recurrence risks, analysis of clonal origins, evaluation of the malignancy trend of precancerous lesions, and determination of clinical prognosis. As a result, many new progresses have been obtained, and new strategies of molecular-pathological diagnosis have been formed. Moreover, the new types of pathobiological diagnosis indicator systems for PLC have been preliminarily established. These achievements provide valuable molecular pathology-based guide for clinical formulation of individualized therapy programs for PLC. This review article briefly summarizes some relevant progresses of molecular-pathological diagnosis of PLC from the perspective of clinical translational application other than basic experimental studies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Photon Upconversion and Molecular Solar Energy Storage by Maximizing the Potential of Molecular Self-Assembly.

PubMed

Kimizuka, Nobuo; Yanai, Nobuhiro; Morikawa, Masa-Aki

2016-11-29

The self-assembly of functional molecules into ordered molecular assemblies and the fulfillment of potentials unique to their nanotomesoscopic structures have been one of the central challenges in chemistry. This Feature Article provides an overview of recent progress in the field of molecular self-assembly with the focus on the triplet-triplet annihilation-based photon upconversion (TTA-UC) and supramolecular storage of photon energy. On the basis of the integration of molecular self-assembly and photon energy harvesting, triplet energy migration-based TTA-UC has been achieved in varied molecular systems. Interestingly, some molecular self-assemblies dispersed in solution or organogels revealed oxygen barrier properties, which allowed TTA-UC even under aerated conditions. The elements of molecular self-assembly were also introduced to the field of molecular solar thermal fuel, where reversible photoliquefaction of ionic crystals to ionic liquids was found to double the molecular storage capacity with the simultaneous pursuit of switching ionic conductivity. A future prospect in terms of innovating molecular self-assembly toward molecular systems chemistry is also discussed.

Molecularly Imprinted Polymer of Colocynthin, An Effective Tool for Quality Control of Citrullus colocynthis Extracts.

PubMed

Farid, Ramezani; Mahnaz, Khanavi; Ardekani Mohammad Reza, Shams; Börje, Sellergren; Mahdieh, Eftekhari; Hossein, Rastegar; Maryam, Shekarchi

2017-01-01

Different parts of Colocynth, Citrullus colocynthis (L.) Schrad., are used in traditional phytotherapy and homeopathy. In our new approach, a molecularly imprinted polymer was synthesized to absorb colocynthin, the major plant marker, and its capability was evaluated using HPLC-UV. A new method was considered to achieve optimal conditions. FT-infrared, N2 adsorption porosimetry, fluorescent and scanning electron microscopy and thermo gravimetric profile of the polymers were studied. The imprinted polymer was applied as molecularly imprinted solid phase extraction sorbent to enrich colocynthin from colocynth oil extract, a traditional medicine dosage form. The imprinted polymer showed high capacity and affinity toward colocynthin. Physical assessments demonstrated no major differences between imprinted and nonimprinted polymers. The imprinted polymer was able to absorb colocynthin more efficiently than non-imprinted and control simple solvent extraction from the real sample. In conclusion, this polymer is capable of being applied as a promising adsorbent for analysis of colocynth traditional medicine products. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Achieving Peace through Education.

ERIC Educational Resources Information Center

Clarken, Rodney H.

While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

Ultra-Fast RAFT-HDA Click Conjugation: An Efficient Route to High Molecular Weight Block Copolymers.

PubMed

Inglis, Andrew J; Stenzel, Martina H; Barner-Kowollik, Christopher

2009-11-02

The use of the reversible addition fragmentation chain transfer-hetero Diels-Alder (RAFT-HDA) click reaction for the modular construction of block copolymers is extended to the generation of high molecular weight materials. Cyclopentadienyl end-functionalized polystyrene (PS-Cp) prepared via both atom transfer radical polymerization (ATRP) and the RAFT process are conjugated to poly(isobornyl acrylate) (PiBoA) (also prepared via RAFT polymerization) to achieve well-defined block copolymers with molecular weights ranging from 34 000 to over 100 000 g · mol(-1) and with small polydispersities (PDI < 1.2). The conjugation reactions proceeded in a very rapid fashion (less than 10 min in the majority of cases) under ambient conditions of temperature and atmosphere. The present study demonstrates-for the first time-that RAFT-HDA click chemistry can provide access to high molecular weight block copolymers in a simple and straight-forward fashion. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enantiomerically enriched, polycrystalline molecular sieves

DOE PAGES

Brand, Stephen K.; Schmidt, Joel E.; Deem, Michael W.; ...

2017-05-01

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. For this study, enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electronmore » microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).« less

Enantiomerically enriched, polycrystalline molecular sieves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brand, Stephen K.; Schmidt, Joel E.; Deem, Michael W.

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. For this study, enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electronmore » microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).« less

Foundational Concepts and Underlying Theories for Majors in "Biochemistry and Molecular Biology"

ERIC Educational Resources Information Center

Tansey, John T.; Baird, Teaster, Jr.; Cox, Michael M.; Fox, Kristin M.; Knight, Jennifer; Sears, Duane; Bell, Ellis

2013-01-01

Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3)…

A National Survey of Music Education Majors' Confidence in Teaching Improvisation

ERIC Educational Resources Information Center

Bernhard, H. Christian, II.; Stringham, David A.

2016-01-01

The purpose of the study was to investigate undergraduate music education majors' confidence in teaching improvisation, according to the NAfME (1994) K-12 Achievement Standards. Specific research questions were: 1) How confident are music education majors in implementing the 11 improvisation achievement standards for grades K-12? 2) How confident…

Molecular Genetic Diversity of Major Indian Rice Cultivars over Decadal Periods

PubMed Central

Deborah, Dondapati Annekitty; Vipparla, Abhilash; Anuradha, Ghanta; Siddiq, Ebrahimali Abubacker; Vemireddy, Lakshminarayana Reddy

2013-01-01

Genetic diversity in representative sets of high yielding varieties of rice released in India between 1970 and 2010 was studied at molecular level employing hypervariable microsatellite markers. Of 64 rice SSR primer pairs studied, 52 showed polymorphism, when screened in 100 rice genotypes. A total of 184 alleles was identified averaging 3.63 alleles per locus. Cluster analysis clearly grouped the 100 genotypes into their respective decadal periods i.e., 1970s, 1980s, 1990s and 2000s. The trend of diversity over the decadal periods estimated based on the number of alleles (Na), allelic richness (Rs), Nei’s genetic diversity index (He), observed heterozygosity (Ho) and polymorphism information content (PIC) revealed increase of diversity over the periods in year of releasewise and longevitywise classification of rice varieties. Analysis of molecular variance (AMOVA) suggested more variation in within the decadal periods than among the decades. Pairwise comparison of population differentiation (Fst) among decadal periods showed significant difference between all the pairs except a few. Analysis of trends of appearing and disappearing alleles over decadal periods showed an increase in the appearance of alleles and decrease in disappearance in both the categories of varieties. It was obvious from the present findings, that genetic diversity was progressively on the rise in the varieties released during the decadal periods, between 1970s and 2000s. PMID:23805204

Molecular cloning of human protein 4.2: a major component of the erythrocyte membrane.

PubMed Central

Sung, L A; Chien, S; Chang, L S; Lambert, K; Bliss, S A; Bouhassira, E E; Nagel, R L; Schwartz, R S; Rybicki, A C

1990-01-01

Protein 4.2 (P4.2) comprises approximately 5% of the protein mass of human erythrocyte (RBC) membranes. Anemia occurs in patients with RBCs deficient in P4.2, suggesting a role for this protein in maintaining RBC stability and integrity. We now report the molecular cloning and characterization of human RBC P4.2 cDNAs. By immunoscreening a human reticulocyte cDNA library and by using the polymerase chain reaction, two cDNA sequences of 2.4 and 2.5 kilobases (kb) were obtained. These cDNAs differ only by a 90-base-pair insert in the longer isoform located three codons downstream from the putative initiation site. The 2.4- and 2.5-kb cDNAs predict proteins of approximately 77 and approximately 80 kDa, respectively, and the authenticity was confirmed by sequence identity with 46 amino acids of three cyanogen bromide-cleaved peptides of P4.2. Northern blot analysis detected a major 2.4-kb RNA species in reticulocytes. Isolation of two P4.2 cDNAs implies existence of specific regulation of P4.2 expression in human RBCs. Human RBC P4.2 has significant homology with human factor XIII subunit a and guinea pig liver transglutaminase. Sequence alignment of P4.2 with these two transglutaminases, however, revealed that P4.2 lacks the critical cysteine residue required for the enzymatic crosslinking of substrates. Images PMID:1689063

The Impact and Racial Identity on Academic Achievement

ERIC Educational Resources Information Center

Mulzac, Anica Camela

2012-01-01

Research has shown that academic achievement among racial minority groups, particularly African Americans, and the majority Caucasian group is profoundly disproportionate. A number of variables have been shown to influence the academic achievement of students, such as stereotype threat, racial identity, and academic self-concept (Awad, 2007;…

The major protein of bovine seminal plasma, PDC-109, is a molecular chaperone.

PubMed

Sankhala, Rajeshwer Singh; Swamy, Musti J

2010-05-11

The major protein of bovine seminal plasma, PDC-109, binds to choline phospholipids on the sperm plasma membrane and induces the efflux of cholesterol and choline phospholipids, which is an important step in sperm capacitation. The high abundance, polydisperse nature and reversibility of thermal unfolding of PDC-109 suggest significant similarities to chaperone-like proteins such as spectrin, alpha-crystallin, and alpha-synuclein. In the present study, biochemical and biophysical approaches were employed to investigate the chaperone-like activity of PDC-109. The effect of various stress factors such as high temperature, chemical denaturant (urea), and acidic pH on target proteins such as lactate dehydrogenase, alcohol dehydrogenase, and insulin were studied in both the presence and absence of PDC-109. The results obtained indicate that PDC-109 exhibits chaperone-like activity, as evidenced by its ability to suppress the nonspecific aggregation of target proteins and direct them into productive folding. Atomic force microscopic studies demonstrate that PDC-109 effectively prevents the fibrillation of insulin, which is of considerable significance since amyloidogenesis has been reported to be a serious problem during sperm maturation in certain species. Binding of phosphorylcholine or high ionic strength in the medium inhibited the chaperone-like activity of PDC-109, suggesting that most likely the aggregation state of the protein is important for the chaperone function. These observations show that PDC-109 functions as a molecular chaperone in vitro, suggesting that it may assist the proper folding of proteins involved in the bovine sperm capacitation pathway. To the best of our knowledge, this is the first study reporting chaperone-like activity of a seminal plasma protein.

EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH).

PubMed

Porto, Graça; Brissot, Pierre; Swinkels, Dorine W; Zoller, Heinz; Kamarainen, Outi; Patton, Simon; Alonso, Isabel; Morris, Michael; Keeney, Steve

2016-04-01

Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines.

Molecular toxicity of nanomaterials.

PubMed

Chang, Xue-Ling; Yang, Sheng-Tao; Xing, Gengmei

2014-10-01

With the rapid developments in the fields of nanoscience and nanotechnlogy, more and more nanomaterials and their based consumer products have been used into our daily life. The safety concerns of nanomaterials have been well recognized by the scientific community and the public. Molecular mechanism of interactions between nanomaterials and biosystems is the most essential topic and final core of the biosafety. In the last two decades, nanotoxicology developed very fast and toxicity phenomena of nanomaterials have been reported. To achieve better understanding and detoxication of nanomaterials, thorough studies of nanotoxicity at molecular level are important. The interactions between nanomaterials and biomolecules have been widely investigated as the first step toward the molecular nanotoxicology. The consequences of such interactions have been discussed in the literature. Besides this, the chemical mechanism of nanotoxicology is gaining more attention, which would lead to a better design of nontoxic nanomaterials. In this review, we focus on the molecular nanotoxicology and explore the toxicity of nanomaterials at molecular level. The molecular level studies of nanotoxicology are summarized and the published nanotoxicological data are revisited.

The effects of higher-order questioning strategies on nonscience majors' achievement in an introductory environmental science course and their attitudes toward the environment

NASA Astrophysics Data System (ADS)

Eason, Grace Teresa

The purpose of this quasi-experimental study was to determine the effect a higher-order questioning strategy (Bloom, 1956) had on undergraduate non-science majors' attitudes toward the environment and their achievement in an introductory environmental science course, EDS 1032, "Survey of Science 2: Life Science," which was offered during the Spring 2000 term. Students from both treatment and control groups (N = 63), which were determined using intact classes, participated in eight cooperative group activities based on the Biological Sciences Curriculum Studies (BSCS) 5E model (Bybee, 1993). The treatment group received a higher-order questioning method combined with the BSCS 5E model. The control group received a lower-order questioning method, combined with the BSCS 5E model. Two instruments were used to measure students' attitude and achievement changes. The Ecology Issue Attitude (EIA) survey (Schindler, 1995) and a comprehensive environmental science final exam. Kolb's Learning Style Inventory (KLSI, 1985) was used to measure students' learning style type. After a 15-week treatment period, results were analyzed using MANCOVA. The overall MANCOVA model used to test the statistical difference between the collective influences of the independent variables on the three dependent variables simultaneously was found to be not significant at alpha = .05. This differs from findings of previous studies in which higher-order questioning techniques had a significant effect on student achievement (King 1989 & 1992; Blosser, 1991; Redfield and Rousseau, 1981; Gall 1970). At the risk of inflated Type I and Type II error rates, separate univariate analyses were performed. However, none of the research factors, when examined collectively or separately, made any significant contribution to explaining the variability in EIA attitude, EIA achievement, and comprehensive environmental science final examination scores. Nevertheless, anecdotal evidence from student's self

Predictors of Academic Achievement and Their Possible Applications

ERIC Educational Resources Information Center

Lockshin, Jeffrey; Zamkov, Oleg

2009-01-01

A significant amount of attention has been given to the predictors of academic achievement in higher education. However, the vast majority of articles have centred on entrance criteria and the learning approaches or personal habits of students. Investigations into how achievement depends on student efforts, being almost invariably based on…

Teacher Dispositions and Student Achievement

ERIC Educational Resources Information Center

Vaughn, Kathleen Adams

2012-01-01

In an effort to close the achievement gap between students of minority and majority populations and between students in higher and lower economic circumstances, the National Council for the Accreditation of Teacher Education (NCATE) added instruction and evaluation of teacher dispositions to its requirements for credentialing prospective teachers.…

Physiology of digestion and the molecular characterization of the major digestive enzymes from Periplaneta americana.

PubMed

Tamaki, Fábio K; Pimentel, André C; Dias, Alcides B; Cardoso, Christiane; Ribeiro, Alberto F; Ferreira, Clélia; Terra, Walter R

2014-11-01

Cockroaches are among the first insects to appear in the fossil record. This work is part of ongoing research on insects at critical points in the evolutionary tree to disclose evolutionary trends in the digestive characteristics of insects. A transcriptome (454 Roche platform) of the midgut of Periplanetaamericana was searched for sequences of digestive enzymes. The selected sequences were manually curated. The complete or nearly complete sequences showing all characteristic motifs and highly expressed (reads counting) had their predicted sequences checked by cloning and Sanger sequencing. There are two chitinases (lacking mucin and chitin-binding domains), one amylase, two α- and three β-glucosidases, one β-galactosidase, two aminopeptidases (none of the N-group), one chymotrypsin, 5 trypsins, and none β-glucanase. Electrophoretic and enzymological data agreed with transcriptome data in showing that there is a single β-galactosidase, two α-glucosidases, one preferring as substrate maltase and the other aryl α-glucoside, and two β-glucosidases. Chromatographic and enzymological data identified 4 trypsins, one chymotrypsin (also found in the transcriptome), and one non-identified proteinase. The major digestive trypsin is identifiable to a major P. americana allergen (Per a 10). The lack of β-glucanase expression in midguts was confirmed, thus lending support to claims that those enzymes are salivary. A salivary amylase was molecularly cloned and shown to be different from the one from the midgut. Enzyme distribution showed that most digestion occurs under the action of salivary and midgut enzymes in the foregut and anterior midgut, except the posterior terminal digestion of proteins. A counter-flux of fluid may be functional in the midgut of the cockroach to explain the low excretory rate of digestive enzymes. Ultrastructural and immunocytochemical localization data showed that amylase and trypsin are released by both merocrine and apocrine secretion

A simple molecular orbital treatment of current distributions in quantum transport through molecular junctions

NASA Astrophysics Data System (ADS)

Jhan, Sin-Mu; Jin, Bih-Yaw

2017-11-01

A simple molecular orbital treatment of local current distributions inside single molecular junctions is developed in this paper. Using the first-order perturbation theory and nonequilibrium Green's function techniques in the framework of Hückel theory, we show that the leading contributions to local current distributions are directly proportional to the off-diagonal elements of transition density matrices. Under the orbital approximation, the major contributions to local currents come from a few dominant molecular orbital pairs which are mixed by the interactions between the molecule and electrodes. A few simple molecular junctions consisting of single- and multi-ring conjugated systems are used to demonstrate that local current distributions inside molecular junctions can be decomposed by partial sums of a few leading contributing transition density matrices.

The CRC 20 years: An overview of some of the major achievements and remaining challenges.

PubMed

Doek, Jaap E

2009-11-01

On 20 November 1989, the General Assembly of the United Nations adopted the Convention on the Rights of the Child (CRC). It entered into force on 2 September 1990 and has by now been ratified by 193 States, making the most universally ratified human rights treaty. This overview will present and discuss the impact of this treaty both at the international and the national level, an overview which necessarily has to be limited to some of the developments as a result of the implementation of the CRC. The first part of this paper will be devoted to the impact the CRC had and still has on the setting and development of the international agenda for the promotion and protection of the rights and welfare of children. Special attention will given to developments, achievements, and remaining challenges at the international level with regard to protection of children in armed conflict; prevention and the protection of children from sexual exploitation; and from all forms of violence. This will include some information on the impact of these international developments and actions at the national level, for example, in the area of legislation. The second part will focus on the impact at the national level. Given the wide scope of the CRC this part will be limited to some of the General Measures of Implementation (law reform, national programmes, and independent monitoring) and the General Principles (non-discrimination, best interest, right to be heard) of the CRC. This will be based on reports of States on the implementation of the CRC submitted to the CRC Committee and the Concluding Observations of this Committee and on a number of studies. The conclusion will provide remarks on poverty as one of the major remaining challenges for the implementation of children's rights.

What Matters, What Works: Advancing Achievement after School

ERIC Educational Resources Information Center

Public/Private Ventures, 2008

2008-01-01

This brief provides highlights from "Advancing Achievement: Findings from an Independent Evaluation of a Major After-School Initiative." The brief underscores the potential of after-school programs in the ongoing drive to advance children's academic achievement. It shines a light on some of the issues that matter most for programs striving to…

Molecular Imaging of Atherothrombotic Diseases: Seeing Is Believing.

PubMed

Wang, Xiaowei; Peter, Karlheinz

2017-06-01

Molecular imaging, with major advances in the development of both innovative targeted contrast agents/particles and radiotracers, as well as various imaging technologies, is a fascinating, rapidly growing field with many preclinical and clinical applications, particularly for personalized medicine. Thrombosis in either the venous or the arterial system, the latter typically caused by rupture of unstable atherosclerotic plaques, is a major determinant of mortality and morbidity in patients. However, imaging of the various thrombotic complications and the identification of plaques that are prone to rupture are at best indirect, mostly unreliable, or not available at all. The development of molecular imaging toward diagnosis and prevention of thrombotic disease holds promise for major advance in this clinically important field. Here, we review the medical need and clinical importance of direct molecular imaging of thrombi and unstable atherosclerotic plaques that are prone to rupture, thereby causing thrombotic complications such as myocardial infarction and ischemic stroke. We systematically compare the advantages/disadvantages of the various molecular imaging modalities, including X-ray computed tomography, magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, fluorescence imaging, and ultrasound. We further systematically discuss molecular targets specific for thrombi and those characterizing unstable, potentially thrombogenic atherosclerotic plaques. Finally, we provide examples for first theranostic approaches in thrombosis, combining diagnosis, targeted therapy, and monitoring of therapeutic success or failure. Overall, molecular imaging is a rapidly advancing field that holds promise of major benefits to many patients with atherothrombotic diseases. © 2017 American Heart Association, Inc.

Superintendents' Responses to the Achievement Gap: An Ethical Critique.

ERIC Educational Resources Information Center

Sherman, Whitney H.; Grogan, Margaret

2003-01-01

Uses multidimensional ethical framework to critique 15 Virginia superintendents' responses to the achievement gap as measured by the Standards of Learning (SOL) tests. Questions majority of superintendents' readiness to deal with moral and ethical issues related to achievement gap. (Contains 24 references.) (PKP)

Graph Theory and Ion and Molecular Aggregation in Aqueous Solutions

NASA Astrophysics Data System (ADS)

Choi, Jun-Ho; Lee, Hochan; Choi, Hyung Ran; Cho, Minhaeng

2018-04-01

In molecular and cellular biology, dissolved ions and molecules have decisive effects on chemical and biological reactions, conformational stabilities, and functions of small to large biomolecules. Despite major efforts, the current state of understanding of the effects of specific ions, osmolytes, and bioprotecting sugars on the structure and dynamics of water H-bonding networks and proteins is not yet satisfactory. Recently, to gain deeper insight into this subject, we studied various aggregation processes of ions and molecules in high-concentration salt, osmolyte, and sugar solutions with time-resolved vibrational spectroscopy and molecular dynamics simulation methods. It turns out that ions (or solute molecules) have a strong propensity to self-assemble into large and polydisperse aggregates that affect both local and long-range water H-bonding structures. In particular, we have shown that graph-theoretical approaches can be used to elucidate morphological characteristics of large aggregates in various aqueous salt, osmolyte, and sugar solutions. When ion and molecular aggregates in such aqueous solutions are treated as graphs, a variety of graph-theoretical properties, such as graph spectrum, degree distribution, clustering coefficient, minimum path length, and graph entropy, can be directly calculated by considering an ensemble of configurations taken from molecular dynamics trajectories. Here we show percolating behavior exhibited by ion and molecular aggregates upon increase in solute concentration in high solute concentrations and discuss compelling evidence of the isomorphic relation between percolation transitions of ion and molecular aggregates and water H-bonding networks. We anticipate that the combination of graph theory and molecular dynamics simulation methods will be of exceptional use in achieving a deeper understanding of the fundamental physical chemistry of dissolution and in describing the interplay between the self-aggregation of solute

Graph Theory and Ion and Molecular Aggregation in Aqueous Solutions.

PubMed

Choi, Jun-Ho; Lee, Hochan; Choi, Hyung Ran; Cho, Minhaeng

2018-04-20

In molecular and cellular biology, dissolved ions and molecules have decisive effects on chemical and biological reactions, conformational stabilities, and functions of small to large biomolecules. Despite major efforts, the current state of understanding of the effects of specific ions, osmolytes, and bioprotecting sugars on the structure and dynamics of water H-bonding networks and proteins is not yet satisfactory. Recently, to gain deeper insight into this subject, we studied various aggregation processes of ions and molecules in high-concentration salt, osmolyte, and sugar solutions with time-resolved vibrational spectroscopy and molecular dynamics simulation methods. It turns out that ions (or solute molecules) have a strong propensity to self-assemble into large and polydisperse aggregates that affect both local and long-range water H-bonding structures. In particular, we have shown that graph-theoretical approaches can be used to elucidate morphological characteristics of large aggregates in various aqueous salt, osmolyte, and sugar solutions. When ion and molecular aggregates in such aqueous solutions are treated as graphs, a variety of graph-theoretical properties, such as graph spectrum, degree distribution, clustering coefficient, minimum path length, and graph entropy, can be directly calculated by considering an ensemble of configurations taken from molecular dynamics trajectories. Here we show percolating behavior exhibited by ion and molecular aggregates upon increase in solute concentration in high solute concentrations and discuss compelling evidence of the isomorphic relation between percolation transitions of ion and molecular aggregates and water H-bonding networks. We anticipate that the combination of graph theory and molecular dynamics simulation methods will be of exceptional use in achieving a deeper understanding of the fundamental physical chemistry of dissolution and in describing the interplay between the self-aggregation of solute

Germacrone derivatives: synthesis, biological activity, molecular docking studies and molecular dynamics simulations.

PubMed

Wu, Jie; Feng, Yu; Han, Chao; Huang, Wu; Shen, Zhibin; Yang, Mengdie; Chen, Weiqiang; Ye, Lianbao

2017-02-28

Germacrone is one of the major bioactive components in the Curcuma zedoaria oil product, which is extracted from Curcuma zedoaria Roscoe, known as zedoary. The present study designed some novel germacrone derivatives based on combination principles, synthesized these compounds, and investigated their inhibitions on Bel-7402, HepG2, A549 and HeLa cells. Meanwhile, the study evaluated inhibitions of these derivatives on c-Met kinase, which has been detected in a number of cancers. The results suggested that the majority of the compounds showed stronger inhibitory effect on cancers and c-Met kinase than germacrone. Furthermore, our docking experiments analyzed the results and explained the molecular mechanism. Molecular dynamics simulations were then applied to perform further evaluation of the binding stabilities between compounds and their receptors.

Surface Immobilization of Molecular Electrocatalysts for Energy Conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullock, R. Morris; Das, Atanu K.; Appel, Aaron M.

2017-03-22

Electrocatalysts are critically important for a secure energy future, as they facilitate the conversion between electrical energy and chemical energy. Molecular catalysts offer precise control of their structure, and the ability to modify the substituents to understand structure-reactivity relationships that are more difficult to achieve with heterogeneous catalysts. Molecular electrocatalysts can be immobilized on surfaces by covalent bonds or through non-covalent interactions. Advantages of surface immobilization include the need for less catalyst, avoidance of bimolecular decomposition pathways, and easier determination of catalyst lifetime. Copper-catalyzed click reactions are often used to form covalent bonds to surfaces, and pi-pi stacking of pyrenemore » substituents appended to the ligand of a molecular complex is a frequently used method to achieve non-covalent surface immobilization. This mini-review highlights surface confinement of molecular electrocatalysts for reduction of O2, oxidation of H2O, production of H2, and reduction of CO2.« less

Packet Fragmentation and Reassembly in Molecular Communication.

PubMed

Furubayashi, Taro; Nakano, Tadashi; Eckford, Andrew; Okaie, Yutaka; Yomo, Tetsuya

2016-04-01

This paper describes packet fragmentation and reassembly to achieve reliable molecular communication among bionanomachines. In the molecular communication described in this paper, a sender bionanomachine performs packet fragmentation, dividing a large molecular message into smaller pieces and embedding into smaller molecular packets, so that molecular packets have higher diffusivity to reach the receiver bionanomachine. The receiver bionanomachine then performs packet reassembly to retrieve the original molecular message from a set of molecular packets that it receives. To examine the effect of packet fragmentation and reassembly, we develop analytical models and conduct numerical experiments. Numerical results show that packet fragmentation and reassembly can improve the message delivery performance. Numerical results also indicate that packet fragmentation and reassembly may degrade the performance in the presence of drift in the environment.

Unidirectional rotary motion in a molecular system

NASA Astrophysics Data System (ADS)

Kelly, T. Ross; de Silva, Harshani; Silva, Richard A.

1999-09-01

The conversion of energy into controlled motion plays an important role in both man-made devices and biological systems. The principles of operation of conventional motors are well established, but the molecular processes used by `biological motors' such as muscle fibres, flagella and cilia to convert chemical energy into co-ordinated movement remain poorly understood. Although `brownian ratchets' are known to permit thermally activated motion in one direction only, the concept of channelling random thermal energy into controlled motion has not yet been extended to the molecular level. Here we describe a molecule that uses chemical energy to activate and bias a thermally induced isomerization reaction, and thereby achieve unidirectional intramolecular rotary motion. The motion consists of a 120° rotation around a single bond connecting a three-bladed subunit to the bulky remainder of the molecule, and unidirectional motion is achieved by reversibly introducing a tether between the two units to energetically favour one of the two possible rotation directions. Although our system does not achieve continuous and fast rotation, the design principles that we have used may prove relevant for a better understanding of biological and synthetic molecular motors producing unidirectional rotary motion.

Soluble Molecularly Imprinted Nanorods for Homogeneous Molecular Recognition

NASA Astrophysics Data System (ADS)

Liang, Rongning; Wang, Tiantian; Zhang, Huan; Yao, Ruiqing; Qin, Wei

2018-03-01

Nowadays, it is still difficult for molecularly imprinted polymer (MIPs) to achieve homogeneous recognition since they cannot be easily dissolved in organic or aqueous phase. To address this issue, soluble molecularly imprinted nanorods have been synthesized by using soluble polyaniline doped with a functionalized organic protonic acid as the polymer matrix. By employing 1-naphthoic acid as a model, the proposed imprinted nanorods exhibit an excellent solubility and good homogeneous recognition ability. The imprinting factor for the soluble imprinted nanoroads is 6.8. The equilibrium dissociation constant and the apparent maximum number of the proposed imprinted nanorods are 248.5 μM and 22.1 μmol/g, respectively. We believe that such imprinted nanorods may provide an appealing substitute for natural receptors in homogeneous recognition related fields.

Molecular similarity measures.

PubMed

Maggiora, Gerald M; Shanmugasundaram, Veerabahu

2011-01-01

Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

Achievements and opportunities from ESF Research Networking Programme: Natural molecular structures as drivers and tracers of terrestrial C fluxes, and COST Action 639: Greenhouse gas budget of soils under changing climate and land use

NASA Astrophysics Data System (ADS)

Boeckx, P.; Rasse, D.; Jandl, R.

2009-04-01

One of the activities of the European Science Foundation (ESF, www.esf.org) is developing European scale Research Networking Programmes (RNPs). RNPs lay the foundation for nationally funded research groups to address major scientific and research infrastructure issues, in order to advance the frontiers of existing science. MOLTER (www.esf.org/molter or www.molter.no) is such an RNP. MOLTER stands for "Natural molecular structures as drivers and tracers of terrestrial C fluxes" aims at stimulating the use of isotopic and organic chemistry to study carbon stabilization and biogeochemistry in terrestrial ecosystems and soils in particular. The understanding of the formation, stabilization and decomposition of complex organic compounds in the environment is currently being revolutionized by advanced techniques in identification, quantification, and origin tracing of functional groups and individual molecules. MOLTER focuses on five major research themes: - Molecular composition and turnover time of soil organic matter; - Plant molecular structures as drivers of C stabilisation in soils; - Fire transformations of plant and soil molecular structures - Molecular markers in soils; - Dissolved organic molecules in soils: origin, functionality and transport. These research themes are covered via the following activities: - Organisation of international conferences; - Organisation of specific topical workshops; - Organisation of summer schools for PhD students; - Short- and long-term exchange grants for scientists. MOLTER is supported by research funding or performing agencies from Austria, Belgium, France, Germany, the Netherlands, Norway, Romania, Spain, Sweden, Switzerland and the United Kingdom. The ESF is also the implementing agency of COST (European Cooperation in Science and Technology, www.cost.esf.org), one of the longest-running European instruments supporting cooperation among scientists and researchers across Europe. COST Action 639 "Greenhouse gas budget of

Molecular Modeling of Estrogen Receptor Using Molecular Operating Environment

ERIC Educational Resources Information Center

Roy, Urmi; Luck, Linda A.

2007-01-01

Molecular modeling is pervasive in the pharmaceutical industry that employs many of our students from Biology, Chemistry and the interdisciplinary majors. To expose our students to this important aspect of their education we have incorporated a set of tutorials in our Biochemistry class. The present article describes one of our tutorials where…

Evolutionary molecular medicine.

PubMed

Nesse, Randolph M; Ganten, Detlev; Gregory, T Ryan; Omenn, Gilbert S

2012-05-01

Evolution has long provided a foundation for population genetics, but some major advances in evolutionary biology from the twentieth century that provide foundations for evolutionary medicine are only now being applied in molecular medicine. They include the need for both proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, competition between alleles, co-evolution, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are transforming evolutionary biology in ways that create even more opportunities for progress at its interfaces with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and related principles to speed the development of evolutionary molecular medicine.

Assessment of Molecular Modeling & Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2002-01-03

This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materialsmore » modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.« less

Modelling Predictors of Molecular Response to Frontline Imatinib for Patients with Chronic Myeloid Leukaemia

PubMed Central

Brown, Fred; Adelson, David; White, Deborah; Hughes, Timothy; Chaudhri, Naeem

2017-01-01

Background Treatment of patients with chronic myeloid leukaemia (CML) has become increasingly difficult in recent years due to the variety of treatment options available and challenge deciding on the most appropriate treatment strategy for an individual patient. To facilitate the treatment strategy decision, disease assessment should involve molecular response to initial treatment for an individual patient. Patients predicted not to achieve major molecular response (MMR) at 24 months to frontline imatinib may be better treated with alternative frontline therapies, such as nilotinib or dasatinib. The aims of this study were to i) understand the clinical prediction ‘rules’ for predicting MMR at 24 months for CML patients treated with imatinib using clinical, molecular, and cell count observations (predictive factors collected at diagnosis and categorised based on available knowledge) and ii) develop a predictive model for CML treatment management. This predictive model was developed, based on CML patients undergoing imatinib therapy enrolled in the TIDEL II clinical trial with an experimentally identified achieving MMR group and non-achieving MMR group, by addressing the challenge as a machine learning problem. The recommended model was validated externally using an independent data set from King Faisal Specialist Hospital and Research Centre, Saudi Arabia. Principle Findings The common prognostic scores yielded similar sensitivity performance in testing and validation datasets and are therefore good predictors of the positive group. The G-mean and F-score values in our models outperformed the common prognostic scores in testing and validation datasets and are therefore good predictors for both the positive and negative groups. Furthermore, a high PPV above 65% indicated that our models are appropriate for making decisions at diagnosis and pre-therapy. Study limitations include that prior knowledge may change based on varying expert opinions; hence, representing

Exploiting β-Cyclodextrin in Molecular Imprinting for Achieving Recognition of Benzylparaben in Aqueous Media

PubMed Central

Asman, Saliza; Mohamad, Sharifah; Muhamad Sarih, Norazilawati

2015-01-01

The molecularly imprinted polymer (MIP) based on methacrylic acid functionalized β-cyclodextrin (MAA-β-CD) monomer was synthesized for the purpose of selective recognition of benzylparaben (BzP). The MAA-β-CD monomer was produced by bridging a methacrylic acid (MAA) and β-cyclodextrin (β-CD) using toluene-2,4-diisocyanate (TDI) by reacting the –OH group of MAA and one of the primary –OH groups of β-CD. This monomer comprised of triple interactions that included an inclusion complex, π–π interaction, and hydrogen bonding. To demonstrate β-CD performance in MIPs, two MIPs were prepared; molecularly imprinted polymer-methacrylic acid functionalized β-cyclodextrin, MIP(MAA-β-CD), and molecularly imprinted polymer-methacrylic acid, MIP(MAA); both prepared by a reversible addition fragmentation chain transfer polymerization (RAFT) in the bulk polymerization process. Both MIPs were characterized using the Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Brunauer-Emmett-Teller (BET). The presence of β-CD not only influenced the morphological structure, it also affected the specific surface area, average pore diameter, and total pore volume of the MIP. The rebinding of the imprinting effect was evaluated in binding experiments, which proved that the β-CD contributed significantly to the enhancement of the recognition affinity and selective adsorption of the MIP. PMID:25667978

Global Molecular Epidemiology of Cryptococcus neoformans and Cryptococcus gattii: An Atlas of the Molecular Types

PubMed Central

Cogliati, Massimo

2013-01-01

Cryptococcosis is a fungal disease affecting more than one million people per year worldwide. The main etiological agents of cryptococcosis are the two sibling species Cryptococcus neoformans and Cryptococcus gattii that present numerous differences in geographical distribution, ecological niches, epidemiology, pathobiology, clinical presentation and molecular characters. Genotyping of the two Cryptococcus species at subspecies level supplies relevant information to understand how this fungus has spread worldwide, the nature of its population structure, and how it evolved to be a deadly pathogen. At present, nine major molecular types have been recognized: VNI, VNII, VNB, VNIII, and VNIV among C. neoformans isolates, and VGI, VGII, VGIII, and VGIV among C. gattii isolates. In this paper all the information available in the literature concerning the isolation of the two Cryptococcus species has been collected and analyzed on the basis of their geographical origin, source of isolation, level of identification, species, and molecular type. A detailed analysis of the geographical distribution of the major molecular types in each continent has been described and represented on thematic maps. This study represents a useful tool to start new epidemiological surveys on the basis of the present knowledge. PMID:24278784

Tunable Single-Cell Extraction for Molecular Analyses.

PubMed

Guillaume-Gentil, Orane; Grindberg, Rashel V; Kooger, Romain; Dorwling-Carter, Livie; Martinez, Vincent; Ossola, Dario; Pilhofer, Martin; Zambelli, Tomaso; Vorholt, Julia A

2016-07-14

Because of cellular heterogeneity, the analysis of endogenous molecules from single cells is of significant interest and has major implications. While micromanipulation or cell sorting followed by cell lysis is already used for subsequent molecular examinations, approaches to directly extract the content of living cells remain a challenging but promising alternative to achieving non-destructive sampling and cell-context preservation. Here, we demonstrate the quantitative extraction from single cells with spatiotemporal control using fluidic force microscopy. We further present a comprehensive analysis of the soluble molecules withdrawn from the cytoplasm or the nucleus, including the detection of enzyme activities and transcript abundances. This approach has uncovered the ability of cells to withstand extraction of up to several picoliters and opens opportunities to study cellular dynamics and cell-cell communication under physiological conditions at the single-cell level. Copyright © 2016 Elsevier Inc. All rights reserved.

EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH)

PubMed Central

Porto, Graça; Brissot, Pierre; Swinkels, Dorine W; Zoller, Heinz; Kamarainen, Outi; Patton, Simon; Alonso, Isabel; Morris, Michael; Keeney, Steve

2016-01-01

Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines. PMID:26153218

Molecular weight distribution of phosphorus fraction of aquatic dissolved organic matter.

PubMed

Ged, Evan C; Boyer, Treavor H

2013-05-01

This study characterized dissolved organic phosphorus (DOP) that is discharged from the Everglades Agricultural Area as part of the larger pool of aquatic dissolved organic matter (DOM). Whole water samples collected at the Everglades stormwater treat area 1 West (STA-1 W) were fractionated using a batch ultrafiltration method to separate organic compounds based on apparent molecular weight (AMW). Each AMW fraction of DOM was characterized for phosphorus, carbon, nitrogen, UV absorbance, and fluorescence. The DOP content of the Everglades water matrix was characteristically variable constituting 4-56% of total phosphorus (TP) and demonstrated no correlation with dissolved organic carbon (DOC). Measured values for DOP exceeded 14μgL(-1) in four out of five sampling dates making phosphorus load reductions problematic for the stormwater treatment areas (STAs), which target inorganic phosphorus and have a goal of 10μgL(-1) as TP. The molecular weight distributions revealed 40% of DOP is high molecular weight, aromatic-rich DOM. The results of this research are expected to be of interest to environmental chemists, environmental engineers, and water resources managers because DOP presents a major obstacle to achieving TP levels <10μgL(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

Medulloblastoma in the Molecular Era

PubMed Central

Miranda Kuzan-Fischer, Claudia; Juraschka, Kyle; Taylor, Michael D.

2018-01-01

Medulloblastoma is the most common malignant brain tumor of childhood and remains a major cause of cancer related mortality in children. Significant scientific advancements have transformed the understanding of medulloblastoma, leading to the recognition of four distinct clinical and molecular subgroups, namely wingless (WNT), sonic hedgehog, group 3, and group 4. Subgroup classification combined with the recognition of subgroup specific molecular alterations has also led to major changes in risk stratification of medulloblastoma patients and these changes have begun to alter clinical trial design, in which the newly recognized subgroups are being incorporated as individualized treatment arms. Despite these recent advancements, identification of effective targeted therapies remains a challenge for several reasons. First, significant molecular heterogeneity exists within the four subgroups, meaning this classification system alone may not be sufficient to predict response to a particular therapy. Second, the majority of novel agents are currently tested at the time of recurrence, after which significant selective pressures have been exerted by radiation and chemotherapy. Recent studies demonstrate selection of tumor sub-clones that exhibit genetic divergence from the primary tumor, exist within metastatic and recurrent tumor populations. Therefore, tumor resampling at the time of recurrence may become necessary to accurately select patients for personalized therapy. PMID:29742881

Medulloblastoma in the Molecular Era.

PubMed

Miranda Kuzan-Fischer, Claudia; Juraschka, Kyle; Taylor, Michael D

2018-05-01

Medulloblastoma is the most common malignant brain tumor of childhood and remains a major cause of cancer related mortality in children. Significant scientific advancements have transformed the understanding of medulloblastoma, leading to the recognition of four distinct clinical and molecular subgroups, namely wingless (WNT), sonic hedgehog, group 3, and group 4. Subgroup classification combined with the recognition of subgroup specific molecular alterations has also led to major changes in risk stratification of medulloblastoma patients and these changes have begun to alter clinical trial design, in which the newly recognized subgroups are being incorporated as individualized treatment arms. Despite these recent advancements, identification of effective targeted therapies remains a challenge for several reasons. First, significant molecular heterogeneity exists within the four subgroups, meaning this classification system alone may not be sufficient to predict response to a particular therapy. Second, the majority of novel agents are currently tested at the time of recurrence, after which significant selective pressures have been exerted by radiation and chemotherapy. Recent studies demonstrate selection of tumor sub-clones that exhibit genetic divergence from the primary tumor, exist within metastatic and recurrent tumor populations. Therefore, tumor resampling at the time of recurrence may become necessary to accurately select patients for personalized therapy.

Molecular Force Spectroscopy on Cells

NASA Astrophysics Data System (ADS)

Liu, Baoyu; Chen, Wei; Zhu, Cheng

2015-04-01

Molecular force spectroscopy has become a powerful tool to study how mechanics regulates biology, especially the mechanical regulation of molecular interactions and its impact on cellular functions. This force-driven methodology has uncovered a wealth of new information of the physical chemistry of molecular bonds for various biological systems. The new concepts, qualitative and quantitative measures describing bond behavior under force, and structural bases underlying these phenomena have substantially advanced our fundamental understanding of the inner workings of biological systems from the nanoscale (molecule) to the microscale (cell), elucidated basic molecular mechanisms of a wide range of important biological processes, and provided opportunities for engineering applications. Here, we review major force spectroscopic assays, conceptual developments of mechanically regulated kinetics of molecular interactions, and their biological relevance. We also present current challenges and highlight future directions.

Achievement Goal Theory: The Relationship of Accounting Students' Goal Orientations with Self-Efficacy, Anxiety, and Achievement

ERIC Educational Resources Information Center

Dull, Richard B.; Schleifer, Lydia L. F.; McMillan, Jeffrey J.

2015-01-01

Students' goal orientations are examined using two major frameworks for learning: achievement goal theory (AGT) and students' approaches to learning (SAL). Previous student success research is extended, by examining goal constructs from the AGT framework to determine if they help explain the learning process in accounting. Data were gathered using…

Molecular Mechanism by which Prominent Human Gut Bacteroidetes Utilize Mixed-Linkage Beta-Glucans, Major Health-Promoting Cereal Polysaccharides.

PubMed

Tamura, Kazune; Hemsworth, Glyn R; Déjean, Guillaume; Rogers, Theresa E; Pudlo, Nicholas A; Urs, Karthik; Jain, Namrata; Davies, Gideon J; Martens, Eric C; Brumer, Harry

2017-10-10

Microbial utilization of complex polysaccharides is a major driving force in shaping the composition of the human gut microbiota. There is a growing appreciation that finely tuned polysaccharide utilization loci enable ubiquitous gut Bacteroidetes to thrive on the plethora of complex polysaccharides that constitute "dietary fiber." Mixed-linkage β(1,3)/β(1,4)-glucans (MLGs) are a key family of plant cell wall polysaccharides with recognized health benefits but whose mechanism of utilization has remained unclear. Here, we provide molecular insight into the function of an archetypal MLG utilization locus (MLGUL) through a combination of biochemistry, enzymology, structural biology, and microbiology. Comparative genomics coupled with growth studies demonstrated further that syntenic MLGULs serve as genetic markers for MLG catabolism across commensal gut bacteria. In turn, we surveyed human gut metagenomes to reveal that MLGULs are ubiquitous in human populations globally, which underscores the importance of gut microbial metabolism of MLG as a common cereal polysaccharide. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

First molecular identification and report of genetic diversity of Strongyloides stercoralis, a current major soil-transmitted helminth in humans from Lao People's Democratic Republic.

PubMed

Laymanivong, Sakhone; Hangvanthong, Bouasy; Insisiengmay, Bounnaloth; Vanisaveth, Viengxay; Laxachack, Pinnakhone; Jongthawin, Jurairat; Sanpool, Oranuch; Thanchomnang, Tongjit; Sadaow, Lakkhana; Phosuk, Issarapong; Rodpai, Rutchanee; Maleewong, Wanchai; Intapan, Pewpan M

2016-08-01

Strongyloidiasis is a major soil-transmitted helminth (STH) disease that affects people worldwide. We present updated data on prevalence in the Lao People's Democratic Republic (Lao PDR) in 2015, arising from a community cross-sectional helminthiasis survey. Fecal samples were collected from 327 individuals across three provinces in Lao PDR (Luang Prabang in the north, Khammouane in the center, and Champasack in the south). Agar plate culture and Kato-Katz methods were used to examine duplicate stool samples from each participant to detect Strongyloides stercoralis and co-infecting helminths. Overall prevalences of S. strercoralis human hookworm, Taenia spp., Trichuris trichiura, Ascaris lumbricoides, and Enterobius vermicularis were 41.0, 28.1, 4.9, 4.0, 1.5, and 0.9 %, respectively. The prevalence of miscellaneous trematodiases (including opisthorchiasis) was 37.9 % and of Schistosoma mekongi infection was 0.3 %. Strongyloidiasis is a current major STH disease in Lao PDR. We also report the molecular-phylogenetic identification of S. stercoralis adult males collected from 40 representative human strongyliodiasis fecal samples. DNA was extracted, amplified, and sequenced from a portion of the mitochondrial cox1 gene and the nuclear 18S ribosomal DNA. Phylogenetic analyses indicated that all specimens sequenced belonged to S. stercoralis (Bavay, 1876) Stiles and Hassall, 1902. The cox1 sequences exhibited great diversity (24 haplotypes) in Lao PDR. This is the first molecular identification and report of genetic diversity of S. stercoralis in humans from Lao PDR. An effective parasite control program is needed to reduce the serious health impacts.

New Molecular Targets of Anticancer Therapy - Current Status and Perspectives.

PubMed

Zajac, Marianna; Muszalska, Izabela; Jelinska, Anna

2016-01-01

Molecularly targeted anticancer therapy involves the use of drugs or other substances affecting specific molecular targets that play a part in the development, progression and spread of a given neoplasm. By contrast, the majority of classical chemotherapeutics act on all rapidly proliferating cells, both healthy and cancerous ones. Target anticancer drugs are designed to achieve a particular aim and they usually act cytostatically, not cytotoxically like classical chemotherapeutics. At present, more than 300 biological molecular targets have been identified. The proteins involved in cellular metabolism include (among others) receptor proteins, signal transduction proteins, mRNA thread matrix synthesis proteins participating in neoplastic transformation, cell cycle control proteins, functional and structural proteins. The receptor proteins that are targeted by currently used anticancer drugs comprise the epithelial growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor(VEGFR). Target anticancer drugs may affect extracellular receptor domains (antibodies) or intracellular receptor domains (tyrosine kinase inhibitors). The blocking of the mRNA thread containing information about the structure of oncogenes (signal transduction proteins) is another molecular target of anticancer drugs. That type of treatment, referred to as antisense therapy, is in clinical trials. When the synthesis of genetic material is disturbed, in most cases the passage to the next cycle phase is blocked. The key proteins responsible for the blockage are cyclines and cycline- dependent kinases (CDK). Clinical trials are focused on natural and synthetic substances capable of blocking various CDKs. The paper discusses the molecular targets and chemical structure of target anticancer drugs that have been approved for and currently applied in antineoplastic therapy together with indications and contraindications for their

Optical Molecular Imaging for Diagnosing Intestinal Diseases

PubMed Central

Kim, Sang-Yeob

2013-01-01

Real-time visualization of the molecular signature of cells can be achieved with advanced targeted imaging techniques using molecular probes and fluorescence endoscopy. This molecular optical imaging in gastrointestinal endoscopy is promising for improving the detection of neoplastic lesions, their characterization for patient stratification, and the assessment of their response to molecular targeted therapy and radiotherapy. In inflammatory bowel disease, this method can be used to detect dysplasia in the presence of background inflammation and to visualize inflammatory molecular targets for assessing disease severity and prognosis. Several preclinical and clinical trials have applied this method in endoscopy; however, this field has just started to evolve. Hence, many problems have yet to be solved to enable the clinical application of this novel method. PMID:24340254

The origin and diversification of eukaryotes: problems with molecular phylogenetics and molecular clock estimation

PubMed Central

Roger, Andrew J; Hug, Laura A

2006-01-01

Determining the relationships among and divergence times for the major eukaryotic lineages remains one of the most important and controversial outstanding problems in evolutionary biology. The sequencing and phylogenetic analyses of ribosomal RNA (rRNA) genes led to the first nearly comprehensive phylogenies of eukaryotes in the late 1980s, and supported a view where cellular complexity was acquired during the divergence of extant unicellular eukaryote lineages. More recently, however, refinements in analytical methods coupled with the availability of many additional genes for phylogenetic analysis showed that much of the deep structure of early rRNA trees was artefactual. Recent phylogenetic analyses of a multiple genes and the discovery of important molecular and ultrastructural phylogenetic characters have resolved eukaryotic diversity into six major hypothetical groups. Yet relationships among these groups remain poorly understood because of saturation of sequence changes on the billion-year time-scale, possible rapid radiations of major lineages, phylogenetic artefacts and endosymbiotic or lateral gene transfer among eukaryotes. Estimating the divergence dates between the major eukaryote lineages using molecular analyses is even more difficult than phylogenetic estimation. Error in such analyses comes from a myriad of sources including: (i) calibration fossil dates, (ii) the assumed phylogenetic tree, (iii) the nucleotide or amino acid substitution model, (iv) substitution number (branch length) estimates, (v) the model of how rates of evolution change over the tree, (vi) error inherent in the time estimates for a given model and (vii) how multiple gene data are treated. By reanalysing datasets from recently published molecular clock studies, we show that when errors from these various sources are properly accounted for, the confidence intervals on inferred dates can be very large. Furthermore, estimated dates of divergence vary hugely depending on the methods

Supramolecular Interactions in Secondary Plant Cell Walls: Effect of Lignin Chemical Composition Revealed with the Molecular Theory of Solvation.

PubMed

Silveira, Rodrigo L; Stoyanov, Stanislav R; Gusarov, Sergey; Skaf, Munir S; Kovalenko, Andriy

2015-01-02

Plant biomass recalcitrance, a major obstacle to achieving sustainable production of second generation biofuels, arises mainly from the amorphous cell-wall matrix containing lignin and hemicellulose assembled into a complex supramolecular network that coats the cellulose fibrils. We employed the statistical-mechanical, 3D reference interaction site model with the Kovalenko-Hirata closure approximation (or 3D-RISM-KH molecular theory of solvation) to reveal the supramolecular interactions in this network and provide molecular-level insight into the effective lignin-lignin and lignin-hemicellulose thermodynamic interactions. We found that such interactions are hydrophobic and entropy-driven, and arise from the expelling of water from the mutual interaction surfaces. The molecular origin of these interactions is carbohydrate-π and π-π stacking forces, whose strengths are dependent on the lignin chemical composition. Methoxy substituents in the phenyl groups of lignin promote substantial entropic stabilization of the ligno-hemicellulosic matrix. Our results provide a detailed molecular view of the fundamental interactions within the secondary plant cell walls that lead to recalcitrance.

Molecular Pathology Informatics.

PubMed

Roy, Somak

2015-06-01

Molecular informatics (MI) is an evolving discipline that will support the dynamic landscape of molecular pathology and personalized medicine. MI provides a fertile ground for development of clinical solutions to bridge the gap between clinical informatics and bioinformatics. Rapid adoption of next generation sequencing (NGS) in the clinical arena has triggered major endeavors in MI that are expected to bring a paradigm shift in the practice of pathology. This brief review presents a broad overview of various aspects of MI, particularly in the context of NGS based testing. Copyright © 2015 Elsevier Inc. All rights reserved.

Comprehensive molecular, genomic and phenotypic analysis of a major clone of Enterococcus faecalis MLST ST40.

PubMed

Zischka, Melanie; Künne, Carsten T; Blom, Jochen; Wobser, Dominique; Sakιnç, Türkân; Schmidt-Hohagen, Kerstin; Dabrowski, P Wojtek; Nitsche, Andreas; Hübner, Johannes; Hain, Torsten; Chakraborty, Trinad; Linke, Burkhard; Goesmann, Alexander; Voget, Sonja; Daniel, Rolf; Schomburg, Dietmar; Hauck, Rüdiger; Hafez, Hafez M; Tielen, Petra; Jahn, Dieter; Solheim, Margrete; Sadowy, Ewa; Larsen, Jesper; Jensen, Lars B; Ruiz-Garbajosa, Patricia; Quiñones Pérez, Dianelys; Mikalsen, Theresa; Bender, Jennifer; Steglich, Matthias; Nübel, Ulrich; Witte, Wolfgang; Werner, Guido

2015-03-12

generally showed a greater capacity of adherence to human cell lines and an increased pathogenic potential in various animal models in combination with an even faster growth in vivo (not in vitro). Molecular, genomic and phenotypic analysis of representative isolates of a major clone of E. faecalis MLST ST40 revealed new insights into the microbiology of a commensal bacterium which can turn into a conditional pathogen.

Coupling molecular catalysts with nanostructured surfaces for efficient solar fuel production

NASA Astrophysics Data System (ADS)

Jin, Tong

Solar fuel generation via carbon dioxide (CO2) reduction is a promising approach to meet the increasing global demand for energy and to minimize the impact of energy consumption on climate change. However, CO2 is thermodynamically stable; its activation often requires the use of appropriate catalysts. In particular, molecular catalysts with well-defined structures and tunability have shown excellent activity in photochemical CO2 reduction. These homogenous catalysts, however, suffer from poor stability under photochemical conditions and difficulty in recycling from the reaction media. Heterogenized molecular catalysts, particularly those prepared by coupling molecular catalysts with solid-state surfaces, have attracted more attention in recent years as potential solutions to address the issues associated with molecular catalysts. In this work, solar CO2 reduction is investigated using systems coupling molecular catalysts with robust nanostructured surfaces. In Chapter 2, heterogenization of macrocyclic cobalt(III) and nickel (II) complexes on mesoporous silica surface was achieved by different methods. Direct ligand derivatization significantly lowered the catalytic activity of Co(III) complex, while grafting the Co(III) complex onto silica surface through Si-O-Co linkage resulted in hybrid catalysts with excellent activity in CO2 reduction in the presence of p-terphenyl as a molecular photosensitizer. An interesting loading effect was observed, in which the optimal activity was achieved at a medium Co(III) surface density. Heterogenization of the Ni(II) complex on silica surface has also been implemented, the poor photocatalytic activity of the hybrid catalyst can be attributed to the intrinsic nature of the homogeneous analogue. This study highlighted the importance of appropriate linking strategies in preparing functional heterogenized molecular catalysts. Coupling molecular complexes with light-harvesting surfaces could avoid the use of expensive molecular

The Black-White Achievement Gap: Do State Policies Matter?

ERIC Educational Resources Information Center

Braun, Henry I.; Wang, Aubrey; Jenkins, Frank; Weinbaum, Elliot

2006-01-01

A longstanding issue in American education is the gap in academic achievement between majority and minority students. The goal of this study is to accumulate and evaluate evidence on the relationship between state education policies and changes in the Black-White achievement gap, while addressing some of the methodological issues that have led to…

Major Difference: An Examination of Student Writing Performance by Major and Its Implications for Business Communication

ERIC Educational Resources Information Center

Sigmar, Lucia S.; Hynes, Geraldine E.

2012-01-01

This study analyzes the writing performance levels of 352 students to determine the extent to which business students are achieving written communication competency and whether differences exist among the business majors. Although most students met or exceeded expectations in format and content on a common writing task, students were weakest in…

Complex Forms of Soil Organic Phosphorus-A Major Component of Soil Phosphorus.

PubMed

McLaren, Timothy I; Smernik, Ronald J; McLaughlin, Mike J; McBeath, Therese M; Kirby, Jason K; Simpson, Richard J; Guppy, Christopher N; Doolette, Ashlea L; Richardson, Alan E

2015-11-17

Phosphorus (P) is an essential element for life, an innate constituent of soil organic matter, and a major anthropogenic input to terrestrial ecosystems. The supply of P to living organisms is strongly dependent on the dynamics of soil organic P. However, fluxes of P through soil organic matter remain unclear because only a minority (typically <30%) of soil organic P has been identified as recognizable biomolecules of low molecular weight (e.g., inositol hexakisphosphates). Here, we use (31)P nuclear magnetic resonance spectroscopy to determine the speciation of organic P in soil extracts fractionated into two molecular weight ranges. Speciation of organic P in the high molecular weight fraction (>10 kDa) was markedly different to that of the low molecular weight fraction (<10 kDa). The former was dominated by a broad peak, which is consistent with P bound by phosphomonoester linkages of supra-/macro-molecular structures, whereas the latter contained all of the sharp peaks that were present in unfractionated extracts, along with some broad signal. Overall, phosphomonoesters in supra-/macro-molecular structures were found to account for the majority (61% to 73%) of soil organic P across the five diverse soils. These soil phosphomonoesters will need to be integrated within current models of the inorganic-organic P cycle of soil-plant terrestrial ecosystems.

Application of molecular dynamics simulations in molecular property prediction II: diffusion coefficient.

PubMed

Wang, Junmei; Hou, Tingjun

2011-12-01

In this work, we have evaluated how well the general assisted model building with energy refinement (AMBER) force field performs in studying the dynamic properties of liquids. Diffusion coefficients (D) have been predicted for 17 solvents, five organic compounds in aqueous solutions, four proteins in aqueous solutions, and nine organic compounds in nonaqueous solutions. An efficient sampling strategy has been proposed and tested in the calculation of the diffusion coefficients of solutes in solutions. There are two major findings of this study. First of all, the diffusion coefficients of organic solutes in aqueous solution can be well predicted: the average unsigned errors and the root mean square errors are 0.137 and 0.171 × 10(-5) cm(-2) s(-1), respectively. Second, although the absolute values of D cannot be predicted, good correlations have been achieved for eight organic solvents with experimental data (R(2) = 0.784), four proteins in aqueous solutions (R(2) = 0.996), and nine organic compounds in nonaqueous solutions (R(2) = 0.834). The temperature dependent behaviors of three solvents, namely, TIP3P water, dimethyl sulfoxide, and cyclohexane have been studied. The major molecular dynamics (MD) settings, such as the sizes of simulation boxes and with/without wrapping the coordinates of MD snapshots into the primary simulation boxes have been explored. We have concluded that our sampling strategy that averaging the mean square displacement collected in multiple short-MD simulations is efficient in predicting diffusion coefficients of solutes at infinite dilution. Copyright © 2011 Wiley Periodicals, Inc.

Molecular Identification of the Schwannomatosis Locus

DTIC Science & Technology

2006-07-01

DAMD17-03-1-0445 TITLE: Molecular Identification of the Schwannomatosis Locus PRINCIPAL INVESTIGATOR: Mia MacCollin, M.D...COVERED (From - To) 1 Jul 2005 – 30 Jun 2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Molecular Identification of the Schwannomatosis Locus 5b...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Background: Schwannomatosis is a recently recognized third major type of

Conserving the linear momentum in stochastic dynamics: Dissipative particle dynamics as a general strategy to achieve local thermostatization in molecular dynamics simulations.

PubMed

Passler, Peter P; Hofer, Thomas S

2017-02-15

Stochastic dynamics is a widely employed strategy to achieve local thermostatization in molecular dynamics simulation studies; however, it suffers from an inherent violation of momentum conservation. Although this short-coming has little impact on structural and short-time dynamic properties, it can be shown that dynamics in the long-time limit such as diffusion is strongly dependent on the respective thermostat setting. Application of the methodically similar dissipative particle dynamics (DPD) provides a simple, effective strategy to ensure the advantages of local, stochastic thermostatization while at the same time the linear momentum of the system remains conserved. In this work, the key parameters to employ the DPD thermostats in the framework of periodic boundary conditions are investigated, in particular the dependence of the system properties on the size of the DPD-region as well as the treatment of forces near the cutoff. Structural and dynamical data for light and heavy water as well as a Lennard-Jones fluid have been compared to simulations executed via stochastic dynamics as well as via use of the widely employed Nose-Hoover chain and Berendsen thermostats. It is demonstrated that a small size of the DPD region is sufficient to achieve local thermalization, while at the same time artifacts in the self-diffusion characteristic for stochastic dynamics are eliminated. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Identification of major allergens in watermelon.

PubMed

Pastor, Carlos; Cuesta-Herranz, Javier; Cases, Barbara; Pérez-Gordo, Marina; Figueredo, Elena; de las Heras, Manuel; Vivanco, Fernando

2009-01-01

Watermelon is a worldwide consumed Cucurbitaceae fruit that can elicit allergic reactions. However, the major allergens of watermelon are not known. The aim of this study is to identify and characterize major allergens in watermelon. Twenty-three patients allergic to watermelon took part in the study. The diagnosis was based on a history of symptoms and positive skin prick-prick tests to watermelon, confirmed by positive open oral challenge testing to watermelon pulp. Allergenic components were detected by SDS-PAGE and immunoblotting. Molecular characterization of IgE-binding bands was performed by N-terminal amino acid sequencing and mass spectrometry. Allergens were purified combining several chromatographic steps. Several IgE binding bands (8-120 kDa) were detected in watermelon extract. Three major allergens were identified as malate dehydrogenase (36 kDa), triose phosphate isomerase (28 kDa) and profilin (13 kDa). Purified allergens individually inhibited IgE binding to the whole watermelon extract. All in all these results indicate that malate dehydrogenase, triose phosphate isomerase and profilin are major allergens involved in watermelon allergy. Copyright (C) 2009 S. Karger AG, Basel.

Exercise Attenuates the Major Hallmarks of Aging

PubMed Central

Garatachea, Nuria; Pareja-Galeano, Helios; Santos-Lozano, Alejandro; Fiuza-Luces, Carmen; Morán, María; Emanuele, Enzo; Joyner, Michael J.; Lucia, Alejandro

2015-01-01

Abstract Regular exercise has multi-system anti-aging effects. Here we summarize how exercise impacts the major hallmarks of aging. We propose that, besides searching for novel pharmaceutical targets of the aging process, more research efforts should be devoted to gaining insights into the molecular mediators of the benefits of exercise and to implement effective exercise interventions for elderly people. PMID:25431878

Major system acquisitions process (A-109)

NASA Technical Reports Server (NTRS)

Saric, C.

1991-01-01

The Major System examined is a combination of elements (hardware, software, facilities, and services) that function together to produce capabilities required to fulfill a mission need. The system acquisition process is a sequence of activities beginning with documentation of mission need and ending with introduction of major system into operational use or otherwise successful achievement of program objectives. It is concluded that the A-109 process makes sense and provides a systematic, integrated management approach along with appropriate management level involvement and innovative and 'best ideas' from private sector in satisfying mission needs.

Quantum Dot Platform for Single-Cell Molecular Profiling

NASA Astrophysics Data System (ADS)

Zrazhevskiy, Pavel S.

In-depth understanding of the nature of cell physiology and ability to diagnose and control the progression of pathological processes heavily rely on untangling the complexity of intracellular molecular mechanisms and pathways. Therefore, comprehensive molecular profiling of individual cells within the context of their natural tissue or cell culture microenvironment is essential. In principle, this goal can be achieved by tagging each molecular target with a unique reporter probe and detecting its localization with high sensitivity at sub-cellular resolution, primarily via microscopy-based imaging. Yet, neither widely used conventional methods nor more advanced nanoparticle-based techniques have been able to address this task up to date. High multiplexing potential of fluorescent probes is heavily restrained by the inability to uniquely match probes with corresponding molecular targets. This issue is especially relevant for quantum dot probes---while simultaneous spectral imaging of up to 10 different probes is possible, only few can be used concurrently for staining with existing methods. To fully utilize multiplexing potential of quantum dots, it is necessary to design a new staining platform featuring unique assignment of each target to a corresponding quantum dot probe. This dissertation presents two complementary versatile approaches towards achieving comprehensive single-cell molecular profiling and describes engineering of quantum dot probes specifically tailored for each staining method. Analysis of expanded molecular profiles is achieved through augmenting parallel multiplexing capacity with performing several staining cycles on the same specimen in sequential manner. In contrast to other methods utilizing quantum dots or other nanoparticles, which often involve sophisticated probe synthesis, the platform technology presented here takes advantage of simple covalent bioconjugation and non-covalent self-assembly mechanisms for straightforward probe

Immigrant Students' Achievements in Croatia, Serbia and Slovenia in Context

ERIC Educational Resources Information Center

Šori, Iztok; Šušteric, Nika; Gaber, Slavko

2011-01-01

Achievement gaps between immigrant and native students indicate failure to assure educational equity in the majority of countries assessed by the Programme for International Student Assessment in 2009 (PISA, 2009). The present article explains disparate achievement results in Europe, first testing the hypothesis of old and new democracies. In…

Analysis of Relationships among Burnout, Academic Achievement, and Self-Regulation

ERIC Educational Resources Information Center

Duru, Erdinç; Duru, Sibel; Balkis, Murat

2014-01-01

This study examined the relationships among burnout, academic achievement, and self-regulation with two structural models. The participants were 383 undergraduates with different majors in a university in the western part of Turkey. The results showed that academic achievement was negatively associated with three dimensions of burnout and was…

Gender and Achievement-Related Beliefs among Engineering Students

NASA Astrophysics Data System (ADS)

Heyman, Gail D.; Martyna, Bryn; Bhatia, Sangeeta

Achievement-related beliefs were examined among a group of 238 college students in engineering (38 female, 104 male) and nonengineering majors (57 female, 39 male) to understand why women enter engineering majors at a low rate and are more likely than men to leave such majors. The results indicated that (a) among the engineering majors, women were more likely than men to identify engineering aptitude as a fixed ability, a belief that was associated with a tendency to drop classes when faced with difficulty; (b) female engineering majors were more likely to perceive male and female engineering students as receiving different treatment than their male counterparts; and (c) female engineering majors tended to place more emphasis on extrinsic factors and less emphasis on intrinsic factors than female nonengineering majors, a pattern not seen among men. Implications for intervention programs are discussed.

Nanowire array chips for molecular typing of rare trafficking leukocytes with application to neurodegenerative pathology

NASA Astrophysics Data System (ADS)

Kwak, Minsuk; Kim, Dong-Joo; Lee, Mi-Ri; Wu, Yu; Han, Lin; Lee, Sang-Kwon; Fan, Rong

2014-05-01

Despite the presence of the blood-brain barrier (BBB) that restricts the entry of immune cells and mediators into the central nervous system (CNS), a small number of peripheral leukocytes can traverse the BBB and infiltrate into the CNS. The cerebrospinal fluid (CSF) is one of the major routes through which trafficking leukocytes migrate into the CNS. Therefore, the number of leukocytes and their phenotypic compositions in the CSF may represent important sources to investigate immune-to-brain interactions or diagnose and monitor neurodegenerative diseases. Due to the paucity of trafficking leucocytes in the CSF, a technology capable of efficient isolation, enumeration, and molecular typing of these cells in the clinical settings has not been achieved. In this study, we report on a biofunctionalized silicon nanowire array chip for highly efficient capture and multiplexed phenotyping of rare trafficking leukocytes in small quantities (50 microliters) of clinical CSF specimens collected from neurodegenerative disease patients. The antibody coated 3D nanostructured materials exhibited vastly improved rare cell capture efficiency due to high-affinity binding and enhanced cell-substrate interactions. Moreover, our platform creates multiple cell capture interfaces, each of which can selectively isolate specific leukocyte phenotypes. A comparison with the traditional immunophenotyping using flow cytometry demonstrated that our novel silicon nanowire-based rare cell analysis platform can perform rapid detection and simultaneous molecular characterization of heterogeneous immune cells. Multiplexed molecular typing of rare leukocytes in CSF samples collected from Alzheimer's disease patients revealed the elevation of white blood cell counts and significant alterations in the distribution of major leukocyte phenotypes. Our technology represents a practical tool for potentially diagnosing and monitoring the pathogenesis of neurodegenerative diseases by allowing an effective

A Teaching Intervention to Increase Achievement of Hispanic Nonscience Majors Taking Physical Science Courses

ERIC Educational Resources Information Center

Poelzer, G. Herold; Zeng, Liang

2008-01-01

This quasi-experimental pilot study of nonscience majors taking a physical science course at a university in South Texas was conducted on Hispanic undergraduate students, and is theory based--an application of attribution theory. That the treatment group outperformed the comparison group provides evidence of the positive effect of having students…

Data warehousing in molecular biology.

PubMed

Schönbach, C; Kowalski-Saunders, P; Brusic, V

2000-05-01

In the business and healthcare sectors data warehousing has provided effective solutions for information usage and knowledge discovery from databases. However, data warehousing applications in the biological research and development (R&D) sector are lagging far behind. The fuzziness and complexity of biological data represent a major challenge in data warehousing for molecular biology. By combining experiences in other domains with our findings from building a model database, we have defined the requirements for data warehousing in molecular biology.

Promoting Student Academic Achievement through Faculty Development about Inclusive Teaching

ERIC Educational Resources Information Center

Schmid, Megan E.; Gillian-Daniel, Donald L.; Kraemer, Sara; Kueppers, Mark

2016-01-01

The achievement gap, disparities in the academic achievement of marginalized students (e.g., underrepresented minority, first generation in their family to attend college, and low socio-economic status undergraduate students) relative to their non-minority peers is a pervasive problem in higher education. It impacts student access to the major and…

Molecular pathogenesis and mechanisms of thyroid cancer

PubMed Central

Xing, Mingzhao

2013-01-01

Thyroid cancer is a common endocrine malignancy. There has been exciting progress in understanding its molecular pathogenesis in recent years, as best exemplified by the elucidation of the fundamental role of several major signalling pathways and related molecular derangements. Central to these mechanisms are the genetic and epigenetic alterations in these pathways, such as mutation, gene copy-number gain and aberrant gene methylation. Many of these molecular alterations represent novel diagnostic and prognostic molecular markers and therapeutic targets for thyroid cancer, which provide unprecedented opportunities for further research and clinical development of novel treatment strategies for this cancer. PMID:23429735

From Fullerene-Polymer to All-Polymer Solar Cells: The Importance of Molecular Packing, Orientation, and Morphology Control.

PubMed

Kang, Hyunbum; Lee, Wonho; Oh, Jiho; Kim, Taesu; Lee, Changyeon; Kim, Bumjoon J

2016-11-15

All-polymer solar cells (all-PSCs), consisting of conjugated polymers as both electron donor (P D ) and acceptor (P A ), have recently attracted great attention. Remarkable progress has been achieved during the past few years, with power conversion efficiencies (PCEs) now approaching 8%. In this Account, we first discuss the major advantages of all-PSCs over fullerene-polymer solar cells (fullerene-PSCs): (i) high light absorption and chemical tunability of P A , which affords simultaneous enhancement of both the short-circuit current density (J SC ) and the open-circuit voltage (V OC ), and (ii) superior long-term stability (in particular, thermal and mechanical stability) of all-PSCs due to entangled long P A chains. In the second part of this Account, we discuss the device operation mechanism of all-PSCs and recognize the major challenges that need to be addressed in optimizing the performance of all-PSCs. The major difference between all-PSCs and fullerene-PSCs originates from the molecular structures and interactions, i.e., the electron transport ability in all-PSCs is significantly affected by the packing geometry of two-dimensional P A chains relative to the electrodes (e.g., face-on or edge-on orientation), whereas spherically shaped fullerene acceptors can facilitate isotropic electron transport properties in fullerene-PSCs. Moreover, the crystalline packing structures of P D and P A at the P D -P A interface greatly affect their free charge carrier generation efficiencies. The design of P A polymers (e.g., main backbone, side chain, and molecular weight) should therefore take account of optimizing three major aspects in all-PSCs: (1) the electron transport ability of P A , (2) the molecular packing structure and orientation of P A , and (3) the blend morphology. First, control of the backbone and side-chain structures, as well as the molecular weight, is critical for generating strong intermolecular assembly of P A and its network, thus enabling high

Faculty Development and Achievement: A Faculty's View.

ERIC Educational Resources Information Center

Braskamp, Larry A.; And Others

The way that 48 faculty at a major research university view their professional aspirations, achievement, and career conflicts between their professional activities and personal relationships was evaluated. In addition, a conceptual framework of faculty development using three professorial ranks as three qualitatively different stages of…

Effect of Direct Teaching Method on the Academic Achievement of High and Low Achievers in the Subject of English at the Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Hamdani, Syed Nisar Hussain; Quraishi, Uzma; Zeeshan, Muhammad

2010-01-01

The major objective of the study was to determine the role of the direct teaching method in the academic achievement of students in English at the secondary level. To achieve the said objective, the Solomon Four-Design pre-test/post-test equivalent group design was considered to be the most useful design for this study. The pre-test was used to…

Molecular dynamics correctly models the unusual major conformation of the GAGU RNA internal loop and with NMR reveals an unusual minor conformation.

PubMed

Spasic, Aleksandar; Kennedy, Scott D; Needham, Laura; Manoharan, Muthiah; Kierzek, Ryszard; Turner, Douglas H; Mathews, David H

2018-05-01

The RNA "GAGU" duplex, (5'GAC GAGU GUCA) 2 , contains the internal loop (5'-GAGU-3') 2 , which has two conformations in solution as determined by NMR spectroscopy. The major conformation has a loop structure consisting of trans -Watson-Crick/Hoogsteen GG pairs, A residues stacked on each other, U residues bulged outside the helix, and all sugars with a C2'- endo conformation. This differs markedly from the internal loops, (5'-G AG C-3') 2 , (5'-A AG U-3') 2 , and (5'-UAGG-3') 2 , which all have cis -Watson-Crick/Watson-Crick AG "imino" pairs flanked by cis -Watson-Crick/Watson-Crick canonical pairs resulting in maximal hydrogen bonding. Here, molecular dynamics was used to test whether the Amber force field (ff99 + bsc0 + OL3) approximates molecular interactions well enough to keep stable the unexpected conformation of the GAGU major duplex structure and the NMR structures of the duplexes containing (5'-G AG C-3') 2 , (5'-A AG U-3') 2 , and (5'-U AG G-3') 2 internal loops. One-microsecond simulations were repeated four times for each of the duplexes starting in their NMR conformations. With the exception of (5'-UAGG-3') 2 , equivalent simulations were also run starting with alternative conformations. Results indicate that the Amber force field keeps the NMR conformations of the duplexes stable for at least 1 µsec. They also demonstrate an unexpected minor conformation for the (5'-GAGU-3') 2 loop that is consistent with newly measured NMR spectra of duplexes with natural and modified nucleotides. Thus, unrestrained simulations led to the determination of the previously unknown minor conformation. The stability of the native (5'-GAGU-3') 2 internal loop as compared to other loops can be explained by changes in hydrogen bonding and stacking as the flanking bases are changed. © 2018 Spasic et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Transferability of molecular markers from major legumes to Lathyrus spp. for their application in mapping and diversity studies.

PubMed

Almeida, Nuno Felipe; Trindade Leitão, Susana; Caminero, Constantino; Torres, Ana Maria; Rubiales, Diego; Vaz Patto, Maria Carlota

2014-01-01

Lathyrus cicera L. (chickling pea) and L. sativus L. (grass pea) have great potential among grain legumes due to their adaptability to inauspicious environments, high protein content and resistance to serious diseases. Nevertheless, due to its past underused, further activities are required to exploit this potential and to capitalise on the advances in molecular biology that enable improved Lathyrus spp. breeding programmes. In this study we evaluated the transferability of molecular markers developed for closely related legume species to Lathyrus spp. (Medicago truncatula, pea, lentil, faba bean and lupin) and tested the application of those new molecular tools on Lathyrus mapping and diversity studies. Genomic and expressed sequence tag microsatellite, intron-targeted amplified polymorphic, resistance gene analogue and defence-related gene markers were tested. In total 128 (27.7 %) and 132 (28.6 %) molecular markers were successfully cross-amplified, respectively in L. cicera and L. sativus. In total, the efficiency of transferability from genomic microsatellites was 5 %, and from gene-based markers, 55 %. For L. cicera, three cleaved amplified polymorphic sequence markers and one derived cleaved amplified polymorphic sequence marker based on the cross-amplified markers were also developed. Nine of those molecular markers were suitable for mapping in a L. cicera recombinant inbred line population. From the 17 molecular markers tested for diversity analysis, six (35 %) in L. cicera and seven (41 %) in L. sativus were polymorphic and discriminate well all the L. sativus accessions. Additionally, L. cicera accessions were clearly distinguished from L. sativus accessions. This work revealed a high number of transferable molecular markers to be used in current genomic studies in Lathyrus spp. Although their usefulness was higher on diversity studies, they represent the first steps for future comparative mapping involving these species.

Multidisciplinary molecular diagnostics: the 9th European meeting on molecular diagnostics.

PubMed

Loonen, Anne J M; Schuurman, Rob; van den Brule, Adriaan J C

2016-01-01

This report presents a summary of the 9th European Meeting on Molecular Diagnostics held in Noordwijk, The Netherlands, 14-16 October 2015. This 3-day conference covered many relevant topics in the field of molecular diagnostics in humans, including infectious disease, oncology, outbreak management, population-based cancer screening, standardization and quality control, chronic diseases and pharmacogenetics. Beyond these different areas, shared values are new technologies and novel technical and clinical applications. Approximately 450 participants, the majority coming from European countries, attended the meeting. Besides high quality scientific presentations, more than 35 diagnostic companies presented their latest innovations, altogether in an informal and inspiring scientific ambience.

Dynamic Responses and Initial Decomposition under Shock Loading: A DFTB Calculation Combined with MSST Method for β-HMX with Molecular Vacancy.

PubMed

He, Zheng-Hua; Chen, Jun; Ji, Guang-Fu; Liu, Li-Min; Zhu, Wen-Jun; Wu, Qiang

2015-08-20

Despite extensive efforts on studying the decomposition mechanism of HMX under extreme condition, an intrinsic understanding of mechanical and chemical response processes, inducing the initial chemical reaction, is not yet achieved. In this work, the microscopic dynamic response and initial decomposition of β-HMX with (1 0 0) surface and molecular vacancy under shock condition, were explored by means of the self-consistent-charge density-functional tight-binding method (SCC-DFTB) in conjunction with multiscale shock technique (MSST). The evolutions of various bond lengths and charge transfers were analyzed to explore and understand the initial reaction mechanism of HMX. Our results discovered that the C-N bond close to major axes had less compression sensitivity and higher stretch activity. The charge was transferred mainly from the N-NO2 group along the minor axes and H atom to C atom during the early compression process. The first reaction of HMX primarily initiated with the fission of the molecular ring at the site of the C-N bond close to major axes. Further breaking of the molecular ring enhanced intermolecular interactions and promoted the cleavage of C-H and N-NO2 bonds. More significantly, the dynamic response behavior clearly depended on the angle between chemical bond and shock direction.

Extremely Stable Polypyrrole Achieved via Molecular Ordering for Highly Flexible Supercapacitors.

PubMed

Huang, Yan; Zhu, Minshen; Pei, Zengxia; Huang, Yang; Geng, Huiyuan; Zhi, Chunyi

2016-01-27

The cycling stability of flexible supercapacitors with conducting polymers as electrodes is limited by the structural breakdown arising from repetitive counterion flow during charging/discharging. Supercapacitors made of facilely electropolymerized polypyrrole (e-PPy) have ultrahigh capacitance retentions of more than 97, 91, and 86% after 15000, 50000, and 100000 charging/discharging cycles, respectively, and can sustain more than 230000 charging/discharging cycles with still approximately half of the initial capacitance retained. To the best of our knowledge, such excellent long-term cycling stability was never reported. The fully controllable electropolymerization shows superiority in molecular ordering, favoring uniform stress distribution and charge transfer. Being left at ambient conditions for even 8 months, e-PPy supercapacitors completely retain the good electrochemical performance. The extremely stable supercapacitors with excellent flexibility and scalability hold considerable promise for the commerical application of flexible and wearable electronics.

Cultural Influences on Gifted Gender Achievement

ERIC Educational Resources Information Center

Freeman, Joan

2004-01-01

In Britain, and reflected in other countries, the academic achievements of gifted girls in school are surpassing those of gifted boys in almost all areas of study and at all ages. This is not true in every country. The British evidence suggests two major reasons for this surge by the gifted girls. Emotionally, British girls are now showing greater…

Molecular cloning and immunoglobulin E reactivity of a natural rubber latex lecithinase homologue, the major allergenic component of Hev b 4.

PubMed

Sunderasan, E; Bahari, A; Arif, S A M; Zainal, Z; Hamilton, R G; Yeang, H Y

2005-11-01

Hev b 4 is an allergenic natural rubber latex (NRL) protein complex that is reactive in skin prick tests and in vitro immunoassays. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Hev b 4 is discerned predominantly at 53-55 kDa together with a 57 kDa minor component previously identified as a cyanogenic glucosidase. Of the 13 NRL allergens recognized by the International Union of Immunological Societies, the 53-55 kDa Hev b 4 major protein is the only candidate that lacks complete cDNA and protein sequence information. We sought to clone the transcript encoding the Hev b 4 major protein, and characterize the native protein and its recombinant form in relation to IgE binding. The 5'/3' rapid amplification of cDNA ends method was employed to obtain the complete cDNA of the Hev b 4 major protein. A recombinant form of the protein was over-expressed in Escherichia coli. The native Hev b 4 major protein was deglycosylated by trifluoromethane sulphonic acid. Western immunoblots of the native, deglycosylated and recombinant proteins were performed using both polyclonal antibodies and sera from latex-allergic patients. The cDNA encoding the Hev b 4 major protein was cloned. Its open reading frame matched lecithinases in the conserved domain database and contained 10 predicted glycosylation sites. Detection of glycans on the Hev b 4 lecithinase homologue confirmed it to be a glycoprotein. The deglycosylated lecithinase homologue was discerned at 40 kDa on SDS-PAGE, this being comparable to the 38.53 kDa mass predicted by its cDNA. Deglycosylation of the lecithinase homologue resulted in the loss of IgE recognition, although reactivity to polyclonal rabbit anti-Hev b 4 was retained. IgE from latex-allergic patients also failed to recognize the non-glycosylated E. coli recombinant lecithinase homologue. The IgE epitopes of the Hev b 4 lecithinase homologue reside mainly in its carbohydrate moiety, which also account for the discrepancy between the observed molecular

Simulating the control of molecular reactions via modulated light fields: from gas phase to solution

NASA Astrophysics Data System (ADS)

Thallmair, Sebastian; Keefer, Daniel; Rott, Florian; de Vivie-Riedle, Regina

2017-04-01

Over the past few years quantum control has proven to be very successful in steering molecular processes. By combining theory with experiment, even highly complex control aims were realized in the gas phase. In this topical review, we illustrate the past achievements on several examples in the molecular context. The next step for the quantum control of chemical processes is to translate the fruitful interplay between theory and experiment to the condensed phase and thus to the regime where chemical synthesis can be supported. On the theory side, increased efforts to include solvent effects in quantum control simulations were made recently. We discuss two major concepts, namely an implicit description of the environment via the density matrix algorithm and an explicit inclusion of solvent molecules. By application to chemical reactions, both concepts conclude that despite environmental perturbations leading to more complex control tasks, efficient quantum control in the condensed phase is still feasible.

Molecular evolution of the major chemosensory gene families in insects.

PubMed

Sánchez-Gracia, A; Vieira, F G; Rozas, J

2009-09-01

Chemoreception is a crucial biological process that is essential for the survival of animals. In insects, olfaction allows the organism to recognise volatile cues that allow the detection of food, predators and mates, whereas the sense of taste commonly allows the discrimination of soluble stimulants that elicit feeding behaviours and can also initiate innate sexual and reproductive responses. The most important proteins involved in the recognition of chemical cues comprise moderately sized multigene families. These families include odorant-binding proteins (OBPs) and chemosensory proteins (CSPs), which are involved in peripheral olfactory processing, and the chemoreceptor superfamily formed by the olfactory receptor (OR) and gustatory receptor (GR) families. Here, we review some recent evolutionary genomic studies of chemosensory gene families using the data from fully sequenced insect genomes, especially from the 12 newly available Drosophila genomes. Overall, the results clearly support the birth-and-death model as the major mechanism of evolution in these gene families. Namely, new members arise by tandem gene duplication, progressively diverge in sequence and function, and can eventually be lost from the genome by a deletion or pseudogenisation event. Adaptive changes fostered by environmental shifts are also observed in the evolution of chemosensory families in insects and likely involve reproductive, ecological or behavioural traits. Consequently, the current size of these gene families is mainly a result of random gene gain and loss events. This dynamic process may represent a major source of genetic variation, providing opportunities for FUTURE specific adaptations.

Demystified … Molecular pathology in oncology

PubMed Central

Crocker, J

2002-01-01

In the past 10 years, molecular biology has found major applications in pathology, particularly in oncology. This has been a field of enormous expansion, where pure science has found a place in clinical practice and is now of everyday use in any academic unit. This demystified review will discuss the techniques used in molecular pathology and then provide examples of how these can be used in oncology. PMID:12456768

Oriented molecular sieve membranes by heteroepitaxial growth.

PubMed

Jeong, Hae-Kwon; Krohn, John; Sujaoti, Khristina; Tsapatsis, Michael

2002-11-06

Heteroepitaxial growth of titanosilicates (ETS-10 and ETS-4) is reported. Using this heteroepitaxial growth, oriented ETS-10/-4 membranes have been fabricated, demonstrating a novel way to achieve preferred orientation of molecular sieve films.

Adaptive molecular evolution of the Major Histocompatibility Complex genes, DRA and DQA, in the genus Equus

PubMed Central

2011-01-01

Background Major Histocompatibility Complex (MHC) genes are central to vertebrate immune response and are believed to be under balancing selection by pathogens. This hypothesis has been supported by observations of extremely high polymorphism, elevated nonsynonymous to synonymous base pair substitution rates and trans-species polymorphisms at these loci. In equids, the organization and variability of this gene family has been described, however the full extent of diversity and selection is unknown. As selection is not expected to act uniformly on a functional gene, maximum likelihood codon-based models of selection that allow heterogeneity in selection across codon positions can be valuable for examining MHC gene evolution and the molecular basis for species adaptations. Results We investigated the evolution of two class II MHC genes of the Equine Lymphocyte Antigen (ELA), DRA and DQA, in the genus Equus with the addition of novel alleles identified in plains zebra (E. quagga, formerly E. burchelli). We found that both genes exhibited a high degree of polymorphism and inter-specific sharing of allele lineages. To our knowledge, DRA allelic diversity was discovered to be higher than has ever been observed in vertebrates. Evidence was also found to support a duplication of the DQA locus. Selection analyses, evaluated in terms of relative rates of nonsynonymous to synonymous mutations (dN/dS) averaged over the gene region, indicated that the majority of codon sites were conserved and under purifying selection (dN

Race, School Achievement, and Educational Inequality: Toward a Student-Based Inquiry Perspective

ERIC Educational Resources Information Center

Wiggan, Greg

2007-01-01

Over the past four decades, there have been numerous discussions on student achievement and school failure. Within this time, the debate over the causes and consequences of racial differences in achievement has been at the heart of the nation's social and political life. The author discusses the major developments in achievement research over the…

Male Saudi Arabian freshman science majors at Jazan University: Their perceptions of parental educational practices on their science achievements

NASA Astrophysics Data System (ADS)

Alrehaly, Essa D.

Examination of Saudi Arabian educational practices is scarce, but increasingly important, especially in light of the country's pace in worldwide mathematics and science rankings. The purpose of the study is to understand and evaluate parental influence on male children's science education achievements in Saudi Arabia. Parental level of education and participant's choice of science major were used to identify groups for the purpose of data analysis. Data were gathered using five independent variables concerning parental educational practices (attitude, involvement, autonomy support, structure and control) and the dependent variable of science scores in high school. The sample consisted of 338 participants and was arbitrarily drawn from the science-based colleges (medical, engineering, and natural science) at Jazan University in Saudi Arabia. The data were tested using Pearson's analysis, backward multiple regression, one way ANOVA and independent t-test. The findings of the study reveal significant correlations for all five of the variables. Multiple regressions revealed that all five of the parents' educational practices indicators combined together could explain 19% of the variance in science scores and parental attitude toward science and educational involvement combined accounted for more than 18% of the variance. Analysis indicates that no significant difference is attributable to parental involvement and educational level. This finding is important because it indicates that, in Saudi Arabia, results are not consistent with research in Western or other Asian contexts.

The academic and nonacademic characteristics of science and nonscience majors in Yemeni high schools

NASA Astrophysics Data System (ADS)

Anaam, Mahyoub Ali

The purposes of this study were: (a) to identify the variables associated with selection of majors; (b) to determine the differences between science and nonscience majors in general, and high and low achievers in particular, with respect to attitudes toward science, integrated science process skills, and logical thinking abilities; and (c) to determine if a significant relationship exists between students' majors and their personality types and learning styles. Data were gathered from 188 twelfth grade male and female high school students in Yemen, who enrolled in science (45 males and 47 females) and art and literature (47 males and 49 females) tracks. Data were collected by the following instruments: Past math and science achievement (data source taken from school records), Kolb's Learning Styles Inventory (1985), Integrated Science Process Skills Test, Myers-Briggs Type Indicator, Attitude Toward Science in School Assessment, Group Assessment of Logical Thinking, Yemeni High School Students Questionnaire. The Logistic Regression Model and the Linear Discriminant Analysis identified several variables that are associated with selection of majors. Moreover, some of the characteristics of science and nonscience majors that were revealed by these models include the following: Science majors seem to have higher degrees of curiosity in science, high interest in science at high school level, high tendency to believe that their majors will help them to find a potential job in the future, and have had higher achievement in science subjects, and have rated their math teachers higher than did nonscience majors. In contrast, nonscience majors seem to have higher degrees of curiosity in nonscience subjects, higher interest in science at elementary school, higher anxiety during science lessons than did science majors. In addition, General Linear Models allow that science majors generally demonstrate more positive attitudes towards science than do nonscience majors and they

Mechanism of molecular recognition on molecular imprinted monolith by capillary electrochromatography.

PubMed

Liu, Zhao-Sheng; Xu, Yan-Li; Yan, Chao; Gao, Ru-Yu

2005-09-16

The recognition mechanism of molecularly imprinted polymer (MIP) in capillary electrochromatography (CEC) is complicated since it possesses a hybrid process, which comprises the features of chromatographic retention, electrophoretic migration and molecular imprinting. For an understanding of the molecular recognition of MIP in CEC, a monolithic MIP in a capillary with 1,1'-binaphthyl-2,2'-diamine (BNA) imprinting was prepared by in situ copolymerization of imprinted molecule, methacrylic acid and ethylene glycol dimethacrylate in porogenic solvent, a mixture of toluene-isooctane. Strong recognition ability and high column performance (theory plates was 43,000 plates/m) of BNA were achieved on this monolithic MIP in CEC mode. In addition, BNA and its structural analogue, 1,1'-bi-2, 2'-naphthol, differing in functional groups, were used as model compounds to study imprinting effect on the resultant BNA-imprinted monolithic column, a reference column without imprinting of BNA and a open capillary. The effects of organic modifier concentration, pH value of buffer, salt concentration of buffer and column temperature on the retention and recognition of two compounds were investigated. The results showed that the molecular recognition on MIP monolith in CEC mode mainly derived from imprinting cavities on BNA-imprinted polymer other than chromatographic retention and electrophoretic migration.

EVOLUTIONARY FOUNDATIONS FOR MOLECULAR MEDICINE

PubMed Central

Nesse, Randolph M.; Ganten, Detlev; Gregory, T. Ryan; Omenn, Gilbert S.

2015-01-01

Evolution has long provided a foundation for population genetics, but many major advances in evolutionary biology from the 20th century are only now being applied in molecular medicine. They include the distinction between proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are further transforming evolutionary biology and creating yet more opportunities for progress at the interface of evolution with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and others to speed the development of evolutionary molecular medicine. PMID:22544168

Effect of Bead and Illustrations Models on High School Students' Achievement in Molecular Genetics

ERIC Educational Resources Information Center

Rotbain, Yosi; Marbach-Ad, Gili; Stavy, Ruth

2006-01-01

Our main goal in this study was to explore whether the use of models in molecular genetics instruction in high school can contribute to students' understanding of concepts and processes in genetics. Three comparable groups of 11th and 12th graders participated: The control group (116 students) was taught in the traditional lecture format, while…

Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake

USGS Publications Warehouse

Soldánová, Miroslava; Georgieva, Simona; Roháčováa, Jana; Knudsen, Rune; Kuhn, Jesper A.; Henriksen, Eirik H.; Siwertsson, Anna; Shaw, Jenny C.; Kuris, Armand M.; Amundsen, Per-Arne; Scholz, Tomáš; Lafferty, Kevin D.; Kostadinova, Aneta

2017-01-01

To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages), and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem, and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

Predicting drug-induced liver injury using ensemble learning methods and molecular fingerprints.

PubMed

Ai, Haixin; Chen, Wen; Zhang, Li; Huang, Liangchao; Yin, Zimo; Hu, Huan; Zhao, Qi; Zhao, Jian; Liu, Hongsheng

2018-05-21

Drug-induced liver injury (DILI) is a major safety concern in the drug-development process, and various methods have been proposed to predict the hepatotoxicity of compounds during the early stages of drug trials. In this study, we developed an ensemble model using three machine learning algorithms and 12 molecular fingerprints from a dataset containing 1,241 diverse compounds. The ensemble model achieved an average accuracy of 71.1±2.6%, sensitivity of 79.9±3.6%, specificity of 60.3±4.8%, and area under the receiver operating characteristic curve (AUC) of 0.764±0.026 in five-fold cross-validation and an accuracy of 84.3%, sensitivity of 86.9%, specificity of 75.4%, and AUC of 0.904 in an external validation dataset of 286 compounds collected from the Liver Toxicity Knowledge Base (LTKB). Compared with previous methods, the ensemble model achieved relatively high accuracy and sensitivity. We also identified several substructures related to DILI. In addition, we provide a web server offering access to our models (http://ccsipb.lnu.edu.cn/toxicity/HepatoPred-EL/).

An Experiment-Oriented Approach to Teaching the Kinetic Molecular Theory.

ERIC Educational Resources Information Center

Wiseman, Frank L., Jr.

1979-01-01

This paper reports an experiment in the teaching of the kinetic molecular theory to nonscience majors by the inquiry method. It allows the student to develop an essentially correct view of gases, liquids, and solids on the atomic or molecular level, and illustrates how one can draw conclusions about the molecular level by simple visual…

Building a personalized medicine infrastructure at a major cancer center.

PubMed

Meric-Bernstam, Funda; Farhangfar, Carol; Mendelsohn, John; Mills, Gordon B

2013-05-20

Our understanding of cancer biology is rapidly increasing, as is the availability and affordability of high throughput technologies for comprehensive molecular characterization of tumors and the individual's own genetic makeup. Thus, the time is right to implement personalized molecular medicine for all patients with cancer. Personalized approaches span the full cancer care spectrum from risk stratification to prevention, screening, therapy, and survivorship programs. Several molecular therapeutics have entered clinical trials creating a huge opportunity to couple genomic markers with this emerging drug tool kit. The number of patients managed in major cancer centers creates a challenge to the implementation of genomic technologies required to successfully deliver on the promise of personalized cancer care. This requires a major investment in infrastructure to facilitate rapid deployment of multiplex, cost-effective, and tissue-sparing assays relevant across multiple tumor lineages in the Clinical Laboratory Improvement Amendments (CLIA) environment. Efforts must be made to ensure that assays are accessible to patients most likely to be enrolled onto molecular-marker-driven trials and that the tests are billable and payable, which will make them accessible to a wide range of patients. As the number of patients and aberrations increase, it will become critical to provide decision support for genomic medicine. Institutional commitment is needed to optimize accessibility and quality of research biopsies and to facilitate novel personalized cancer therapy trials. This article will focus on the challenges and opportunities that accompany the building of infrastructure for personalized cancer therapy.

Using a Computer Animation to Teach High School Molecular Biology

ERIC Educational Resources Information Center

Rotbain, Yosi; Marbach-Ad, Gili; Stavy, Ruth

2008-01-01

We present an active way to use a computer animation in secondary molecular genetics class. For this purpose we developed an activity booklet that helps students to work interactively with a computer animation which deals with abstract concepts and processes in molecular biology. The achievements of the experimental group were compared with those…

Does High School Homework Increase Academic Achievement?

ERIC Educational Resources Information Center

Kalenkoski, Charlene Marie; Pabilonia, Sabrina Wulff

2017-01-01

Although previous research has shown that homework improves students' academic achievement, the majority of these studies use data on students' homework time from retrospective questionnaires, which may be less accurate than time-diary data. We use data from the combined Child Development Supplement (CDS) and the Transition to Adulthood Survey…

Structural disorder within sendai virus nucleoprotein and phosphoprotein: insight into the structural basis of molecular recognition.

PubMed

Jensen, Malene Ringkjøbing; Bernadó, Pau; Houben, Klaartje; Blanchard, Laurence; Marion, Dominque; Ruigrok, Rob W H; Blackledge, Martin

2010-08-01

Intrinsically disordered regions of significant length are present throughout eukaryotic genomes, and are particularly prevalent in viral proteins. Due to their inherent flexibility, these proteins inhabit a conformational landscape that is too complex to be described by classical structural biology. The elucidation of the role that conformational flexibility plays in molecular function will redefine our understanding of the molecular basis of biological function, and the development of appropriate technology to achieve this aim remains one of the major challenges for the future of structural biology. NMR is the technique of choice for studying intrinsically disordered proteins, providing information about structure, flexibility and interactions at atomic resolution even in completely disordered proteins. In particular residual dipolar couplings (RDCs) are sensitive and powerful tools for determining local and long-range structural behaviour in flexible proteins. Here we describe recent applications of the use of RDCs to quantitatively describe the level of local structure in intrinsically disordered proteins involved in replication and transcription in Sendai virus.

Preface - From molecules to molecular materials, biological molecular systems and nanostructures: A collection of contributions presented at the XIIIth International Conference on Molecular Spectroscopy

NASA Astrophysics Data System (ADS)

Ratajczak, Henryk; Drozd, Marek; Fausto, Rui

2016-12-01

This volume contains a series of selected contributions presented at the XIIIth International Conference on Molecular Spectroscopy (ICMS): "From Molecules to Molecular Materials, Biological Molecular Systems and Nanostructures" held in Wrocław, Poland, 9-12 September 2015, under the auspices of the Mayor of Wrocław and the European Academy of Sciences, Arts and Humanities. Wrocław was chosen not accidentally as venue for the conference. With more than a thousand years of history, Wrocław is the location of one of the oldest universities in Central Europe. Being a place where education and science play major roles in the daily life of its inhabitants, Wrocław is also a privileged center for spectroscopy in Poland.

Modeling Complex Workflow in Molecular Diagnostics

PubMed Central

Gomah, Mohamed E.; Turley, James P.; Lu, Huimin; Jones, Dan

2010-01-01

One of the hurdles to achieving personalized medicine has been implementing the laboratory processes for performing and reporting complex molecular tests. The rapidly changing test rosters and complex analysis platforms in molecular diagnostics have meant that many clinical laboratories still use labor-intensive manual processing and testing without the level of automation seen in high-volume chemistry and hematology testing. We provide here a discussion of design requirements and the results of implementation of a suite of lab management tools that incorporate the many elements required for use of molecular diagnostics in personalized medicine, particularly in cancer. These applications provide the functionality required for sample accessioning and tracking, material generation, and testing that are particular to the evolving needs of individualized molecular diagnostics. On implementation, the applications described here resulted in improvements in the turn-around time for reporting of more complex molecular test sets, and significant changes in the workflow. Therefore, careful mapping of workflow can permit design of software applications that simplify even the complex demands of specialized molecular testing. By incorporating design features for order review, software tools can permit a more personalized approach to sample handling and test selection without compromising efficiency. PMID:20007844

The Genetics of Major Depression

PubMed Central

Flint, Jonathan; Kendler, Kenneth S.

2014-01-01

Major depression is the commonest psychiatric disorder and in the U.S. has the greatest impact of all biomedical diseases on disability. Here we review evidence of the genetic contribution to disease susceptibility and the current state of molecular approaches. Genome-wide association and linkage results provide constraints on the allele frequencies and effect sizes of susceptibility loci, which we use to interpret the voluminous candidate gene literature. We consider evidence for the genetic heterogeneity of the disorder and the likelihood that subtypes exist that represent more genetically homogenous conditions than have hitherto been analyzed. PMID:24507187

In vivo nanoparticle-mediated radiopharmaceutical-excited fluorescence molecular imaging

PubMed Central

Hu, Zhenhua; Qu, Yawei; Wang, Kun; Zhang, Xiaojun; Zha, Jiali; Song, Tianming; Bao, Chengpeng; Liu, Haixiao; Wang, Zhongliang; Wang, Jing; Liu, Zhongyu; Liu, Haifeng; Tian, Jie

2015-01-01

Cerenkov luminescence imaging utilizes visible photons emitted from radiopharmaceuticals to achieve in vivo optical molecular-derived signals. Since Cerenkov radiation is weak, non-optimum for tissue penetration and continuous regardless of biological interactions, it is challenging to detect this signal with a diagnostic dose. Therefore, it is challenging to achieve useful activated optical imaging for the acquisition of direct molecular information. Here we introduce a novel imaging strategy, which converts γ and Cerenkov radiation from radioisotopes into fluorescence through europium oxide nanoparticles. After a series of imaging studies, we demonstrate that this approach provides strong optical signals with high signal-to-background ratios, an ideal tissue penetration spectrum and activatable imaging ability. In comparison with present imaging techniques, it detects tumour lesions with low radioactive tracer uptake or small tumour lesions more effectively. We believe it will facilitate the development of nuclear and optical molecular imaging for new, highly sensitive imaging applications. PMID:26123615

Development of haplotype-specific molecular markers for the low-molecular-weight glutenin subunits

USDA-ARS?s Scientific Manuscript database

Low-molecular-weight glutenin subunits (LMW-GSs) are one of the major components of gluten and their allelic variation has been widely associated with numerous wheat end-use quality parameters. These proteins are encoded by multigene families located at the orthologous Glu-3 loci (Glu-A3, Glu-B3 and...

The Neglected Majority--20th Anniversary

ERIC Educational Resources Information Center

Beebe, Anthony E.; Walleri, R. Dan

2005-01-01

It is the 20th anniversary of the release of Dale Parnell's landmark book "The Neglected Majority". In this book, Parnell pointed out that for too long America's educational system has focused on the highest and lowest achievers. He made the case that most of those students in the middle two high school quartiles neither prepare for nor aspire to…

Effects of Peer Academic Reputation on Achievement in Academically At-Risk Elementary Students

ERIC Educational Resources Information Center

Hughes, Jan N.; Dyer, Nicole; Luo, Wen; Kwok, Oi-Man

2009-01-01

664 relatively low achieving first grade children were recruited into a longitudinal study. Measures of peer academic reputation (PAR), peer acceptance, teacher-rated academic engagement and achievement, and reading and math achievement were obtained in Year 2, when the majority of students were in second grade, and 1 year later. Measures of…

Student academic achievement in college chemistry

NASA Astrophysics Data System (ADS)

Tabibzadeh, Kiana S.

General Chemistry is required for variety of baccalaureate degrees, including all medical related fields, engineering, and science majors. Depending on the institution, the prerequisite requirement for college level General Chemistry varies. The success rate for this course is low. The purpose of this study is to examine the factors influencing student academic achievement and retention in General Chemistry at the college level. In this study student achievement is defined by those students who earned grades of "C" or better. The dissertation contains in-depth studies on influence of Intermediate Algebra as a prerequisite compared to Fundamental Chemistry for student academic achievement and student retention in college General Chemistry. In addition the study examined the extent and manner in which student self-efficacy influences student academic achievement in college level General Chemistry. The sample for this part of the study is 144 students enrolled in first semester college level General Chemistry. Student surveys determined student self-efficacy level. The statistical analyses of study demonstrated that Fundamental Chemistry is a better prerequisite for student academic achievement and student retention. The study also found that student self-efficacy has no influence on student academic achievement. The significance of this study will be to provide data for the purpose of establishing a uniform and most suitable prerequisite for college level General Chemistry. Finally the variables identified to influence student academic achievement and enhance student retention will support educators' mission to maximize the students' ability to complete their educational goal at institutions of higher education.

Molecular contributions to conservation

USGS Publications Warehouse

Haig, Susan M.

1998-01-01

Recent advances in molecular technology have opened a new chapter in species conservation efforts, as well as population biology. DNA sequencing, MHC (major histocompatibility complex), minisatellite, microsatellite, and RAPD (random amplified polymorphic DNA) procedures allow for identification of parentage, more distant relatives, founders to new populations, unidentified individuals, population structure, effective population size, population-specific markers, etc. PCR (polymerase chain reaction) amplification of mitochondrial DNA, nuclear DNA, ribosomal DNA, chloroplast DNA, and other systems provide for more sophisticated analyses of metapopulation structure, hybridization events, and delineation of species, subspecies, and races, all of which aid in setting species recovery priorities. Each technique can be powerful in its own right but is most credible when used in conjunction with other molecular techniques and, most importantly, with ecological and demographic data collected from the field. Surprisingly few taxa of concern have been assayed with any molecular technique. Thus, rather than showcasing exhaustive details from a few well-known examples, this paper attempts to present a broad range of cases in which molecular techniques have been used to provide insight into conservation efforts.

Structural study of biologically significant ligands with major birch pollen allergen Betv1 by docking and molecular dynamics simulation

PubMed Central

Kundu, Sangeeta; Roy, Debjani

2010-01-01

The major birch pollen allergen, Betv1 of Betula verrucosa is the main causative agent of birch pollen allergy in humans. Betv1 is capable of binding several physiological ligands including fatty acids, flavones, cytokinins and sterols. Until now, no structural information from crystallography or NMR is available regarding binding mode of any of these ligands into the binding pocket of Betv1. In the present study thirteen ligands have been successfully docked into the hydrophobic cavity of Betv1 and binding free energies of the complexes have been calculated using AutoDock 3.0.5. A linear relationship with correlation coefficient (R2) of 0.6 is obtained between ΔGbs values plotted against their corresponding IC50 values. The complex formed between Betv1 and the best docking pose for each ligand has been optimized by molecular dynamics simulation. Here, we describe the ligand binding of Betv1, which provides insight into the biological function of this protein. This knowledge is required for structural alteration or inhibition of some of these ligands in order to modify the allergenic properties of this protein. PMID:20978606

Molecular dynamics simulations of large macromolecular complexes.

PubMed

Perilla, Juan R; Goh, Boon Chong; Cassidy, C Keith; Liu, Bo; Bernardi, Rafael C; Rudack, Till; Yu, Hang; Wu, Zhe; Schulten, Klaus

2015-04-01

Connecting dynamics to structural data from diverse experimental sources, molecular dynamics simulations permit the exploration of biological phenomena in unparalleled detail. Advances in simulations are moving the atomic resolution descriptions of biological systems into the million-to-billion atom regime, in which numerous cell functions reside. In this opinion, we review the progress, driven by large-scale molecular dynamics simulations, in the study of viruses, ribosomes, bioenergetic systems, and other diverse applications. These examples highlight the utility of molecular dynamics simulations in the critical task of relating atomic detail to the function of supramolecular complexes, a task that cannot be achieved by smaller-scale simulations or existing experimental approaches alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Advancing the education in molecular diagnostics: the IFCC-Initiative "Clinical Molecular Biology Curriculum" (C-CMBC); a ten-year experience.

PubMed

Lianidou, Evi; Ahmad-Nejad, Parviz; Ferreira-Gonzalez, Andrea; Izuhara, Kenji; Cremonesi, Laura; Schroeder, Maria-Eugenia; Richter, Karin; Ferrari, Maurizio; Neumaier, Michael

2014-09-25

Molecular techniques are becoming commonplace in the diagnostic laboratory. Their applications influence all major phases of laboratory medicine including predisposition/genetic risk, primary diagnosis, therapy stratification and prognosis. Readily available laboratory hardware and wetware (i.e. consumables and reagents) foster rapid dissemination to countries that are just establishing molecular testing programs. Appropriate skill levels extending beyond the technical procedure are required for analytical and diagnostic proficiency that is mandatory in molecular genetic testing. An international committee (C-CMBC) of the International Federation for Clinical Chemistry (IFCC) was established to disseminate skills in molecular genetic testing in member countries embarking on the respective techniques. We report the ten-year experience with different teaching and workshop formats for beginners in molecular diagnostics. Copyright © 2014 Elsevier B.V. All rights reserved.

Achievements and Future Directions of the APFCB Mass Spectrometry Harmonisation Project on Serum Testosterone.

PubMed

Greaves, Ronda F; Ho, Chung S; Hoad, Kirsten E; Joseph, John; McWhinney, Brett; Gill, Janice P; Koal, Therese; Fouracre, Chris; Iu, Heidi P; Cooke, Brian R; Boyder, Conchita; Pham, Hai T; Jolly, Lisa M

2016-05-01

As an outcome of the 2010 Asian Pacific Conference for Chromatography and Mass Spectrometry in Hong Kong, a collaborative working group was formed to promote the harmonisation of mass spectrometry methods. The Mass Spectrometry Harmonisation Working Group resides under the combined auspices of the Asia-Pacific Federation for Clinical Biochemistry and Laboratory Medicine (APFCB) and the Australasian Association of Clinical Biochemists (AACB). A decision was made to initially focus attention on serum steroids due to the common interest of members in this area; with the first steroid to assess being testosterone. In principle, full standardisation with traceability should be achievable for all steroids as they are small compounds with defined molecular weight and structure. In order to achieve this we need certified reference materials, reference methods, reference laboratories, reference intervals and external quality assurance programs; each being an important pillar in the process. When all the pillars are present, such as for serum testosterone, it is feasible to fully standardise the liquid chromatography - tandem mass spectrometry (LC-MS/MS) methods. In a collaborative process with interested stakeholders, we commenced on a pathway to provide ongoing assessment and seek opportunities for improvement in the LC-MS/MS methods for serum steroids. Here we discuss the outcomes to date and major challenges related to the accurate measurement of serum steroids with a focus on serum testosterone.

Stereodivergent synthesis with a programmable molecular machine

NASA Astrophysics Data System (ADS)

Kassem, Salma; Lee, Alan T. L.; Leigh, David A.; Marcos, Vanesa; Palmer, Leoni I.; Pisano, Simone

2017-09-01

It has been convincingly argued that molecular machines that manipulate individual atoms, or highly reactive clusters of atoms, with Ångström precision are unlikely to be realized. However, biological molecular machines routinely position rather less reactive substrates in order to direct chemical reaction sequences, from sequence-specific synthesis by the ribosome to polyketide synthases, where tethered molecules are passed from active site to active site in multi-enzyme complexes. Artificial molecular machines have been developed for tasks that include sequence-specific oligomer synthesis and the switching of product chirality, a photo-responsive host molecule has been described that is able to mechanically twist a bound molecular guest, and molecular fragments have been selectively transported in either direction between sites on a molecular platform through a ratchet mechanism. Here we detail an artificial molecular machine that moves a substrate between different activating sites to achieve different product outcomes from chemical synthesis. This molecular robot can be programmed to stereoselectively produce, in a sequential one-pot operation, an excess of any one of four possible diastereoisomers from the addition of a thiol and an alkene to an α,β-unsaturated aldehyde in a tandem reaction process. The stereodivergent synthesis includes diastereoisomers that cannot be selectively synthesized through conventional iminium-enamine organocatalysis. We anticipate that future generations of programmable molecular machines may have significant roles in chemical synthesis and molecular manufacturing.

Tobacco still a major killer-will we achieve the end game?

PubMed

Saboga-Nunes, Luis; Levin-Zamir, Diane; Rabius, Vance

2017-10-01

The game of tobacco use began in Europe in 1560 when the first tobacco seeds were sent from Lisbon to the king of France, by Jean Nicot. From kings' and nobles' exclusive use, it gradually and progressively became popular among the public, as a new player. Eighty-eight years ago (1929), Fritz Linkint, an extraordinary researcher in Germany, while reviewing existing evidence regarding a wide range of cancers potentially caused by smoking, indicated that smoking was a cause of respiratory disease. Despite the overwhelming accumulated evidence of the negative effects of nicotine intake, the prevalence of tobacco use is not expected to decline in the near future. What have we missed thus far in the game that claims more than seven million deaths annually worldwide? Although tobacco use is recognized as a major health problem, the persistent habit creates a dissonance between public health initiatives to reduce tobacco consumption and the choices citizens are making. To understand this dissonance, consideration first must be given to the social meaning attributed to smoking. Second, the political dissonance between health imperatives and social agendas is discussed with regard to relevant theory. Third, health promotion strategies can make a strong contribution to win the game from a negentropic perspective, that is to say, a public health vision that is structured towards an overarching goal. © The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Molecular mimicry between protein and tRNA.

PubMed

Nakamura, Y

2001-01-01

Mimicry is a sophisticated development in animals, fish, and plants that allows them to fool others by imitating a shape or color for diverse purposes, such as to prey, evade, lure, pollinate, or threaten. This is not restricted to the macro-world, but extends to the micro-world as molecular mimicry. Recent advances in structural and molecular biology uncovered a set of translation factors that resembles a tRNA shape and, in one case, even mimics a tRNA function for deciphering the genetic code. Nature must have evolved this art of molecular mimicry between protein and ribonucleic acid by using different protein structures until the translation factors sat in the cockpit of a ribosome machine, on behalf of tRNA, and achieved diverse actions. Structural, functional, and evolutionary aspects of molecular mimicry will be discussed.

Evaluation of Intrarehearsal Achievement by Listeners of Varying Levels of Expertise

ERIC Educational Resources Information Center

Montemayor, Mark

2016-01-01

The primary purpose of this study was to investigate expertise-related differences in the evaluation of moment-to-moment rehearsal achievement. Nonmusic majors, music education majors, and expert music teachers (N = 60) listened to 18 "before" and "after" pairs of rehearsal trials of various high school bands in their pursuit…

The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

PubMed

Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

2006-08-01

We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

Training Program in Marine Molecular Biology

DTIC Science & Technology

1989-09-01

marine biology, to the techniques of modern cell and molecular biology. Marine biology has been slow to apply these techniques for a number of...Beckman Instruments and Pharmacia--LKB. These two companies are due a major vote of thanks for their cooperation and generosity. Many individuals from...the two companies were involved, but particular thanks go to Tim Stebbins (Beckman), Mike Cammarata and Julie Perinne (Pharmacia--LKB) for their major

New concepts for molecular magnets

NASA Astrophysics Data System (ADS)

Pilawa, Bernd

1999-03-01

Miller and Epstein (1994) define molecular magnets as magnetic materials which are prepared by the low-temperature methods of the preparative chemistry. This definition includes molecular crystals of neutral radicals, radical salts and charge transfer complexes as well as metal complexes and polymers with unpaired spins (Dormann 1995). The challenge of molecular magnets consists in tailoring magnetic properties by specific modifications of the molecular units. The combination of magnetism with mechanical or electrical properties of molecular compounds promise materials of high technical interest (Gatteschi 1994a and 1994b, Möhwald 1996) and both the chemical synthesis of new molecular materials with magnetic properties as well as the physical investigation and explanation of these properties is important, in order to achieve any progress. This work deals with the physical characterization of the magnetic properties of molecular materials. It is organized as follows. In the first part molecular crystals of neutral radicals are studied. After briefly discussing the general magnetic properties of these materials and after an overview over the physical principles of exchange interaction between organic radicals I focus on the interplay between the crystallographic structure and the magnetic properties of various derivatives of the verdazyl and nitronyl nitroxide radicals. The magnetic properties of metal complexes are the subject of the second part. After an overview over the experimental and theoretical tools which are used for the investigation of the magnetic properties I shortly discuss the exchange coupling of transition metal ions and the magnetic properties of complexes of two and three metal ions. Special emphasis is given to spin cluster compounds. Spin cluster denote complexes of many magnetic ions. They are attractive as building blocks of molecular magnets as well as magnetic model compounds for the study of spin frustration, molecular super

MOLECULAR SYSTEMATICS OF THE AVIAN SCHISTOSOME GENUS TRICHOBILHARZIA (TREMATODA: SCHISTOSOMATIDAE) IN NORTH AMERICA

PubMed Central

Brant, Sara V.; Loker, Eric S.

2010-01-01

Trichobilharzia is a genus of thread-like schistosomes with a cosmopolitan distribution in birds. Species of Trichobilharzia achieve notoriety as major etiological agents of cercarial dermatitis, or swimmer’s itch. There are 40 species described in the literature, for which the majority lacks molecular sequence information. To better understand the phylogenetic relationships, diversity, species boundaries, host use, and geographic distribution of this genus, we surveyed 378 birds and over 10,000 snails from North America. The phylogenetic analysis was based on nuclear 18S, 28S rDNA, internal transcribed spacer region and mitochondrial cytochrome oxidase I sequence data. Specimens were recovered that could be related to 6 of the 14 described species of Trichobilharzia from North America (T. physellae, T. querquedulae, T. szidati, T. stagnicolae, T. franki, and T. brantae). An additional 5 lineages were found that could not be related directly to previously described species. Trichobilharzia brantae, transmitted by Gyraulus parvus, grouped outside the clade containing the recognized species of Trichobilharzia. A subgroup of the Trichobilharzia clade designated Clade Q was comprised of closely related species whose adults and eggs are similar, yet the European species use lymnaeids whereas the North American species use physids as snail hosts. This molecular phylogeny provides a useful framework to: 1) facilitate identification of worms, including those involved in dermatitis outbreaks; 2) test hypotheses about the evolution, diversification, host-parasite interactions and character evolution of Trichobilharzia; and 3) guide future taxonomic revision of Trichobilharzia. PMID:20049999

Paradoxical Personality and Academic Achievement in College Students From Buenos Aires

PubMed Central

Freiberg Hoffmann, Agustín; Fernández Liporace, María Mercedes

2015-01-01

This paper presents a study on paradoxical personality, defined as a distinctive feature in creative persons, developed with 350 college students from Buenos Aires. Goals aimed at describing and analysing possible significant differences of paradoxical traits in students from diverse majors representing seven different fields of study, and examining the relationship between each bipolar trait and academic achievement. The sample was composed of 7 groups (n = 50 by group) representing fields of study typically offered in public universities, Biology, Computer Science, Engineering, Law, Nutrition, Psychology, and History of Art. Analyses by career provided descriptive information about students of these majors, concerning their paradoxical personality profiles. Correlational studies verified significant associations between academic achievement and most paradoxical traits in majors such as Computer Science, Nutrition and Psychology. Results are discussed regarding practical outcomes and teaching programs. PMID:27247680

Coupling molecular spin centers to microwave resonators: steps towards the implementation of molecular qubits for hybrid quantum circuits

NASA Astrophysics Data System (ADS)

Bonizzoni, Claudio; Ghirri, Alberto; Affronte, Marco

Hybrid spin-photons quantum bits can be obtained under strong coupling regime between microwave photons and a spin ensemble, where coherent exchange of photons is realized. Molecular spins systems, thanks to their tailorable magnetic properties, are retained promising candidates for hybrid qubits. We present an experimental study of the coupling regimes between a high critical temperature YBCO superconducting resonator and different molecular spin ensembles. Three mononuclear compounds, (PPh4)2[Cu(mnt)2], [ErPc2]-TBA+ , Dy(trensal) and two organic radicals, DPPH and PyBTM, are studied. Strong coupling is found in radicals thanks to exchange narrowing. Possible strategies to achieve strong coupling with mononuclear compounds are discussed, and several hints in the design of molecular spins are given.

Virtual Transgenics: Using a Molecular Biology Simulation to Impact Student Academic Achievement and Attitudes

NASA Astrophysics Data System (ADS)

Shegog, Ross; Lazarus, Melanie M.; Murray, Nancy G.; Diamond, Pamela M.; Sessions, Nathalie; Zsigmond, Eva

2012-10-01

The transgenic mouse model is useful for studying the causes and potential cures for human genetic diseases. Exposing high school biology students to laboratory experience in developing transgenic animal models is logistically prohibitive. Computer-based simulation, however, offers this potential in addition to advantages of fidelity and reach. This study describes and evaluates a computer-based simulation to train advanced placement high school science students in laboratory protocols, a transgenic mouse model was produced. A simulation module on preparing a gene construct in the molecular biology lab was evaluated using a randomized clinical control design with advanced placement high school biology students in Mercedes, Texas ( n = 44). Pre-post tests assessed procedural and declarative knowledge, time on task, attitudes toward computers for learning and towards science careers. Students who used the simulation increased their procedural and declarative knowledge regarding molecular biology compared to those in the control condition (both p < 0.005). Significant increases continued to occur with additional use of the simulation ( p < 0.001). Students in the treatment group became more positive toward using computers for learning ( p < 0.001). The simulation did not significantly affect attitudes toward science in general. Computer simulation of complex transgenic protocols have potential to provide a "virtual" laboratory experience as an adjunct to conventional educational approaches.

Factors Associated with Asian American Students' Choice of STEM Major

ERIC Educational Resources Information Center

Lowinger, Robert; Song, Hyun-a

2017-01-01

This study explored Asian American students' likelihood of selecting STEM over liberal arts or business college majors using the Education Longitudinal Study of 2002. Student-level variables were the strongest predictors of college major, followed by parent-level variables, and background variables. Academic achievement and interest were the…

Candida albicans, the opportunist. A cellular and molecular perspective.

PubMed

Dupont, P F

1995-02-01

Candida albicans causes the majority of opportunistic fungal infections. The yeast's commensualistic relationship with humans enables it, when environmental conditions are favorable, to multiply and replace much of the normal flora. Virulence factors of C. albicans, enabling the organism to adhere to and penetrate host tissues, involve specific molecular interactions between the cells of the fungus and the host. Localized disease, such as oral candidiasis, onychomycosis, and vaginitis, results. These infections are usually limited to surfaces of the host, and can be quickly and successfully controlled by the use of one of the available antifungal agents. Candida albicans infections typically become systemic and life threatening when the host is immunocompromised. Depending on the immune defect in the host, one of the spectrum of Candida diseases can develop. If successful treatment of these patients is to be achieved, modulation of the immune deficit, as well as the use of an appropriate antifungal drug, must become a routine part of therapeutic interventions.

A mitochondrial genome phylogeny of termites (Blattodea: Termitoidae): robust support for interfamilial relationships and molecular synapomorphies define major clades.

PubMed

Cameron, Stephen L; Lo, Nathan; Bourguignon, Thomas; Svenson, Gavin J; Evans, Theodore A

2012-10-01

Despite their ecological significance as decomposers and their evolutionary significance as the most speciose eusocial insect group outside the Hymenoptera, termite (Blattodea: Termitoidae or Isoptera) evolutionary relationships have yet to be well resolved. Previous morphological and molecular analyses strongly conflict at the family level and are marked by poor support for backbone nodes. A mitochondrial (mt) genome phylogeny of termites was produced to test relationships between the recognised termite families, improve nodal support and test the phylogenetic utility of rare genomic changes found in the termite mt genome. Complete mt genomes were sequenced for 7 of the 9 extant termite families with additional representatives of each of the two most speciose families Rhinotermitidae (3 of 7 subfamilies) and Termitidae (3 of 8 subfamilies). The mt genome of the well supported sister-group of termites, the subsocial cockroach Cryptocercus, was also sequenced. A highly supported tree of termite relationships was produced by all analytical methods and data treatment approaches, however the relationship of the termites+Cryptocercus clade to other cockroach lineages was highly affected by the strong nucleotide compositional bias found in termites relative to other dictyopterans. The phylogeny supports previously proposed suprafamilial termite lineages, the Euisoptera and Neoisoptera, a later derived Kalotermitidae as sister group of the Neoisoptera and a monophyletic clade of dampwood (Stolotermitidae, Archotermopsidae) and harvester termites (Hodotermitidae). In contrast to previous termite phylogenetic studies, nodal supports were very high for family-level relationships within termites. Two rare genomic changes in the mt genome control region were found to be molecular synapomorphies for major clades. An elongated stem-loop structure defined the clade Polyphagidae + (Cryptocercus+termites), and a further series of compensatory base changes in this stem-loop is

Reticular synthesis of porous molecular 1D nanotubes and 3D networks.

PubMed

Slater, A G; Little, M A; Pulido, A; Chong, S Y; Holden, D; Chen, L; Morgan, C; Wu, X; Cheng, G; Clowes, R; Briggs, M E; Hasell, T; Jelfs, K E; Day, G M; Cooper, A I

2017-01-01

Synthetic control over pore size and pore connectivity is the crowning achievement for porous metal-organic frameworks (MOFs). The same level of control has not been achieved for molecular crystals, which are not defined by strong, directional intermolecular coordination bonds. Hence, molecular crystallization is inherently less controllable than framework crystallization, and there are fewer examples of 'reticular synthesis', in which multiple building blocks can be assembled according to a common assembly motif. Here we apply a chiral recognition strategy to a new family of tubular covalent cages to create both 1D porous nanotubes and 3D diamondoid pillared porous networks. The diamondoid networks are analogous to MOFs prepared from tetrahedral metal nodes and linear ditopic organic linkers. The crystal structures can be rationalized by computational lattice-energy searches, which provide an in silico screening method to evaluate candidate molecular building blocks. These results are a blueprint for applying the 'node and strut' principles of reticular synthesis to molecular crystals.

Reticular synthesis of porous molecular 1D nanotubes and 3D networks

NASA Astrophysics Data System (ADS)

Slater, A. G.; Little, M. A.; Pulido, A.; Chong, S. Y.; Holden, D.; Chen, L.; Morgan, C.; Wu, X.; Cheng, G.; Clowes, R.; Briggs, M. E.; Hasell, T.; Jelfs, K. E.; Day, G. M.; Cooper, A. I.

2017-01-01

Synthetic control over pore size and pore connectivity is the crowning achievement for porous metal-organic frameworks (MOFs). The same level of control has not been achieved for molecular crystals, which are not defined by strong, directional intermolecular coordination bonds. Hence, molecular crystallization is inherently less controllable than framework crystallization, and there are fewer examples of 'reticular synthesis', in which multiple building blocks can be assembled according to a common assembly motif. Here we apply a chiral recognition strategy to a new family of tubular covalent cages to create both 1D porous nanotubes and 3D diamondoid pillared porous networks. The diamondoid networks are analogous to MOFs prepared from tetrahedral metal nodes and linear ditopic organic linkers. The crystal structures can be rationalized by computational lattice-energy searches, which provide an in silico screening method to evaluate candidate molecular building blocks. These results are a blueprint for applying the 'node and strut' principles of reticular synthesis to molecular crystals.

A meta-analysis of self-reported achievement goals and nonself-report performance across three achievement domains (work, sports, and education).

PubMed

Van Yperen, Nico W; Blaga, Monica; Postmes, Tom

2014-01-01

During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual's drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports) are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not) generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG) measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that - overall - approach goals (either mastery or performance) were associated positively with performance attainment, whereas avoidance goals (either mastery or performance) were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of performance

A Meta-Analysis of Self-Reported Achievement Goals and Nonself-Report Performance across Three Achievement Domains (Work, Sports, and Education)

PubMed Central

Van Yperen, Nico W.; Blaga, Monica; Postmes, Tom

2014-01-01

During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual’s drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports) are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not) generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG) measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that – overall – approach goals (either mastery or performance) were associated positively with performance attainment, whereas avoidance goals (either mastery or performance) were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of

Enhanced Molecular Sieve CO2 Removal Evaluation

NASA Technical Reports Server (NTRS)

Rose, Susan; ElSherif, Dina; MacKnight, Allen

1996-01-01

The objective of this research is to quantitatively characterize the performance of two major types of molecular sieves for two-bed regenerative carbon dioxide removal at the conditions compatible with both a spacesuit and station application. One sorbent is a zeolite-based molecular sieve that has been substantially improved over the materials used in Skylab. The second sorbent is a recently developed carbon-based molecular sieve. Both molecular sieves offer the potential of high payoff for future manned missions by reducing system complexity, weight (including consumables), and power consumption in comparison with competing concepts. The research reported here provides the technical data required to improve CO2 removal systems for regenerative life support systems for future IVA and EVA missions.

Molecular evolution tracks macroevolutionary transitions in Cetacea.

PubMed

McGowen, Michael R; Gatesy, John; Wildman, Derek E

2014-06-01

Cetacea (whales, dolphins, and porpoises) is a model group for investigating the molecular signature of macroevolutionary transitions. Recent research has begun to reveal the molecular underpinnings of the remarkable anatomical and behavioral transformation in this clade. This shift from terrestrial to aquatic environments is arguably the best-understood major morphological transition in vertebrate evolution. The ancestral body plan and physiology were extensively modified and, in many cases, these crucial changes are recorded in cetacean genomes. Recent studies have highlighted cetaceans as central to understanding adaptive molecular convergence and pseudogene formation. Here, we review current research in cetacean molecular evolution and the potential of Cetacea as a model for the study of other macroevolutionary transitions from a genomic perspective. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isomeric organic semiconductors containing fused-thiophene cores: molecular packing and charge transport.

PubMed

Dang, Dongfeng; Zhou, Pei; Wu, Yong; Xu, Yanzi; Zhi, Ying; Zhu, Weiguo

2018-05-16

Isomeric TF1 and TF2 with highly fused thiophene cores were designed and synthesized here, in which a highly planar molecular structure was obtained for TF1 with the face-to-face sulfur atoms in the lateral region and a twisted molecular backbone was observed for TF2 with the back-to-back sulfur atoms. It is worth noting that different intermolecular interactions dominated in TF1 and TF2 caused by their isomeric thiophene cores, in which strong π-π stacking was achieved for TF1, whereas sulphur-involved nonbonding intermolecular interactions dominated in TF2, leading to the different fluorescence behaviors and also the altered liquid crystalline phases. Finally, typical P-type charge transport behaviors were achieved in both TF1- and TF2-based solution-processed OFETs. Also owing to the much ordered molecular packing in TF1, a higher charge carrier mobility of 3.7 × 10-3 cm2 V-1 s-1 was achieved for TF1-based OFETs compared to TF2-based OFETs.

First Molecular Epidemiological Study of Cutaneous Leishmaniasis in Libya

PubMed Central

Amro, Ahmad; Gashout, Aisha; Al-Dwibe, Hamida; Zahangir Alam, Mohammad; Annajar, Badereddin; Hamarsheh, Omar; Shubar, Hend; Schönian, Gabriele

2012-01-01

Background Cutaneous leishmaniasis (CL) is a major public health problem in Libya. The objective of this study was to investigate, for the first time, epidemiological features of CL outbreaks in Libya including molecular identification of parasites, the geographical distribution of cases and possible scenarios of parasite transmission. Methodology/Principal Findings We studied 450 patients that came from 49 areas distributed in 12 districts in north-west Libya. The patients' ages ranged from 9 months to 87 years (median age 25 years); 54% of the cases were males. Skin scrapings spotted on glass slides were collected for molecular identification of causative agent. The ribosomal internal transcribed spacer 1 (ITS1) was amplified and subsequently characterized by restriction fragment length polymorphism (RFLP) analysis. In total, 195 samples were successfully identified of which 148 (75.9%) were Leishmania major, and 47 (24.1%) Leishmania tropica. CL cases infected with L. major were found in all CL areas whereas L. tropica cases came mainly from Al Jabal Al Gharbi (46.4%), Misrata (17.8%) and Tarhuna districts (10.7%). A trend of seasonality was noticed for the infections with L. major which showed a clear peak between November and January, but was less pronounced for infections by L. tropica. Conclusion The first molecular study on CL in Libya revealed that the disease is caused by L. major and L. tropica and the epidemiological patterns in the different foci were the same as in other Mediterranean foci of CL. PMID:22724036

First molecular epidemiological study of cutaneous leishmaniasis in Libya.

PubMed

Amro, Ahmad; Gashout, Aisha; Al-Dwibe, Hamida; Zahangir Alam, Mohammad; Annajar, Badereddin; Hamarsheh, Omar; Shubar, Hend; Schönian, Gabriele

2012-01-01

Cutaneous leishmaniasis (CL) is a major public health problem in Libya. The objective of this study was to investigate, for the first time, epidemiological features of CL outbreaks in Libya including molecular identification of parasites, the geographical distribution of cases and possible scenarios of parasite transmission. We studied 450 patients that came from 49 areas distributed in 12 districts in north-west Libya. The patients' ages ranged from 9 months to 87 years (median age 25 years); 54% of the cases were males. Skin scrapings spotted on glass slides were collected for molecular identification of causative agent. The ribosomal internal transcribed spacer 1 (ITS1) was amplified and subsequently characterized by restriction fragment length polymorphism (RFLP) analysis. In total, 195 samples were successfully identified of which 148 (75.9%) were Leishmania major, and 47 (24.1%) Leishmania tropica. CL cases infected with L. major were found in all CL areas whereas L. tropica cases came mainly from Al Jabal Al Gharbi (46.4%), Misrata (17.8%) and Tarhuna districts (10.7%). A trend of seasonality was noticed for the infections with L. major which showed a clear peak between November and January, but was less pronounced for infections by L. tropica. The first molecular study on CL in Libya revealed that the disease is caused by L. major and L. tropica and the epidemiological patterns in the different foci were the same as in other Mediterranean foci of CL.

Theranostics of prostate cancer: from molecular imaging to precision molecular radiotherapy targeting the prostate specific membrane antigen.

PubMed

Kulkarni, Harshad R; Singh, Aviral; Langbein, Thomas; Schuchardt, Christiane; Mueller, Dirk; Zhang, Jingjing; Lehmann, Coline; Baum, Richard P

2018-06-01

Alterations at the molecular level are a hallmark of cancer. Prostate cancer is associated with the overexpression of prostate-specific membrane antigen (PSMA) in a majority of cases, predominantly in advanced tumors, increasing with the grade or Gleason's score. PSMA can be selectively targeted using radiolabeled PSMA ligands. These small molecules binding the PSMA can be radiolabeled with γ-emitters like 99m Tc and 111 In or positron emitters like 68 Ga and 18 F for diagnosis as well as with their theranostic pairs such as 177 Lu (β-emitter) or 225 Ac (α-emitter) for therapy. This review summarizes the theranostic role of PSMA ligands for molecular imaging and targeted molecular radiotherapy, moving towards precision oncology.

The merger of electrochemistry and molecular electronics.

PubMed

McCreery, Richard L

2012-02-01

Molecular Electronics has the potential to greatly enhance existing silicon-based microelectronics to realize new functions, higher device density, lower power consumption, and lower cost. Although the investigation of electron transport through single molecules and molecular monolayers in "molecular junctions" is a recent development, many of the relevant concepts and phenomena are derived from electrochemistry, as practiced for the past several decades. The past 10+ years have seen an explosion of research activity directed toward how the structure of molecules affects electron transport in molecular junctions, with the ultimate objective of "rational design" of molecular components with new electronic functions, such as chemical sensing, interactions with light, and low-cost, low-power consumer electronics. In order to achieve these scientifically and commercially important objectives, the factors controlling charge transport in molecules "connected" to conducting contacts must be understood, and methods for massively parallel manufacturing of molecular circuits must be developed. This Personal Account describes the development of reproducible and robust molecular electronic devices, starting with modified electrodes used in electrochemistry and progressing to manufacturable molecular junctions. Although the field faced some early difficulties in reliability and characterization, the pieces are now in place for rapid advances in understanding charge transport at the molecular level. Inherent in the field of Molecular Electronics are many electrochemical concepts, including tunneling, redox exchange, activated electron transfer, and electron coupling between molecules and conducting contacts. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Molecular Diagnosis of Tuberculosis.

PubMed

Nurwidya, Fariz; Handayani, Diah; Burhan, Erlina; Yunus, Faisal

2018-01-01

Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by Mycobacterium tuberculosis (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.

Minor and major health: a Nietzschean reading.

PubMed

Biato, Emília Carvalho Leitão; Costa, Luciano Bedin da; Monteiro, Silas Borges

2017-03-01

This paper aims to discuss the concept of health, understood as multiple and plural. We use Friedrich Nietzsche's philosophical thought as an analytical tool, allowing us to reach a typology involving minor and major health. While the first is normative and sustained by an ideal of healing, the second is an expanding strength, a condition constantly achieved. If minor health follows a preset life moralization script, major health relates to the expanded living being, which affirms its creative nature and transcends established rules. The notion of major health embraces the overcoming of imperative models rooted in biomedicine-based practices and approaches to health collective actions. Nevertheless, on the one hand, if this movement extends the co-participatory nature between staff and users of the health system, on the other hand, it lacks more radical actions to break with the moral nature of health-disease processes. Not refusing life's own vicissitudes, major health understands the need to incorporate pain and suffering involved in individuation movements.

Department of Energy Other Major Laboratories and Facilities

Science.gov Websites

major laboratories and facilities. This high-level compilation of their history and achievements Laboratory (NBL) History About Background/History of the Laboratory New Brunswick Laboratory website TOP dropdown listing Oak Ridge Institute for Science and Education (ORISE) History Environmental Assessments

Major Variations in HIV-1 Capsid Assembly Morphologies Involve Minor Variations in Molecular Structures of Structurally Ordered Protein Segments*

PubMed Central

Lu, Jun-Xia; Bayro, Marvin J.; Tycko, Robert

2016-01-01

We present the results of solid state nuclear magnetic resonance (NMR) experiments on HIV-1 capsid protein (CA) assemblies with three different morphologies, namely wild-type CA (WT-CA) tubes with 35–60 nm diameters, planar sheets formed by the Arg18-Leu mutant (R18L-CA), and R18L-CA spheres with 20–100 nm diameters. The experiments are intended to elucidate molecular structural variations that underlie these variations in CA assembly morphology. We find that multidimensional solid state NMR spectra of 15N,13C-labeled CA assemblies are remarkably similar for the three morphologies, with only small differences in 15N and 13C chemical shifts, no significant differences in NMR line widths, and few differences in the number of detectable NMR cross-peaks. Thus, the pronounced differences in morphology do not involve major differences in the conformations and identities of structurally ordered protein segments. Instead, morphological variations are attributable to variations in conformational distributions within disordered segments, which do not contribute to the solid state NMR spectra. Variations in solid state NMR signals from certain amino acid side chains are also observed, suggesting differences in the intermolecular dimerization interface between curved and planar CA lattices, as well as possible differences in intramolecular helix-helix packing. PMID:27129282

The Impact of Physics Teachers' Pedagogical Content Knowledge and Motivation on Students' Achievement and Interest

ERIC Educational Resources Information Center

Keller, Melanie M.; Neumann, Knut; Fischer, Hans E.

2017-01-01

This paper examines students' achievement and interest and the extent to which they are predicted by teacher knowledge and motivation. Student achievement and interest are both considered desirable outcomes of school instruction. Teacher pedagogical content knowledge has been identified a major predictor of student achievement in previous…

Molecular basis of P450 OleTJE: an investigation of substrate binding mechanism and major pathways

NASA Astrophysics Data System (ADS)

Du, Juan; Liu, Lin; Guo, Li Zhong; Yao, Xiao Jun; Yang, Jian Ming

2017-05-01

Cytochrome P450 OleTJE has attracted much attention for its ability to catalyze the decarboxylation of long chain fatty acids to generate alkenes, which are not only biofuel molecule, but also can be used broadly for making lubricants, polymers and detergents. In this study, the molecular basis of the binding mechanism of P450 OleTJE for arachidic acid, myristic acid, and caprylic acid was investigated by utilizing conventional molecular dynamics simulation and binding free energy calculations. Moreover, random acceleration molecular dynamics (RAMD) simulations were performed to uncover the most probable access/egress channels for different fatty acids. The predicted binding free energy shows an order of arachidic acid < myristic acid < caprylic acid. Key residues interacting with three substrates and residues specifically binding to one of them were identified. The RAMD results suggest the most likely channel for arachidic acid, myristic acid, and caprylic acid are 2e/2b, 2a and 2f/2a, respectively. It is suggested that the reaction is easier to carry out in myristic acid bound system than those in arachidic acid and caprylic acid bound system based on the distance of Hβ atom of substrate relative to P450 OleTJE Compound I states. This study provided novel insight to understand the substrate preference mechanism of P450 OleTJE and valuable information for rational enzyme design for short chain fatty acid decarboxylation.

Facts and Fiction: The Impact of Hypothermia on Molecular Mechanisms following Major Challenge

PubMed Central

Frink, Michael; Flohé, Sascha; van Griensven, Martijn; Mommsen, Philipp; Hildebrand, Frank

2012-01-01

Numerous multiple trauma and surgical patients suffer from accidental hypothermia. While induced hypothermia is commonly used in elective cardiac surgery due to its protective effects, accidental hypothermia is associated with increased posttraumatic complications and even mortality in severely injured patients. This paper focuses on protective molecular mechanisms of hypothermia on apoptosis and the posttraumatic immune response. Although information regarding severe trauma is limited, there is evidence that induced hypothermia may have beneficial effects on the posttraumatic immune response as well as apoptosis in animal studies and certain clinical situations. However, more profound knowledge of mechanisms is necessary before randomized clinical trials in trauma patients can be initiated. PMID:22481864

The molecular composition of ambers

USGS Publications Warehouse

Grimalt, J.O.; Simoneit, B.R.T.; Hatcher, P.G.; Nissenbaum, A.

1988-01-01

Bulk (elemental composition, IR, CP/MAS 13C NMR) and molecular (GC-MS) analyses have been performed on a series of ambers and resins derived from different locations (Dominican Republic, Philippines, Canada, Israel, New Zealand, Chile) having diverse botanical affinities (Araucariaceae, Hymenaea) and variable age (from Holocene to Early Cretaceous). No major differences have been observed from the elemental composition and the spectroscopic data; however, the molecular analyses of the solvent extractable fraction show that a specific mixture of components is present in each sample. These are mainly diterpenoid products that in general are also found abundantly in the higher plants from which the ambers and resins originate. Nevertheless, a direct relationship between major terpenoid constituents in fossil resins and precursor plant materials can only be established for the younger samples. Irrespective of the geographical or botanical origin of the ambers and resins, several common age-dependent molecular transformation trends can be recognized: (1) progressive loss of olefinic bonds (especially those located in exocyclic positions), (2) decrease of functionalized products, and (3) increasing proportion of aromatized components. However, even in the samples of older age (Cretaceous) the degree of aromatization is very low when compared with that of other higher-plant related materials such as fossilized woods or low rank coals. This indicates that maturation must involve essentially olefin polymerization processes instead of extensive aromatization. ?? 1988.

Strategic Curricular Decisions in Butler University's Actuarial Science Major

ERIC Educational Resources Information Center

Wilson, Christopher James

2014-01-01

We describe specific curricular decisions employed at Butler University that have resulted in student achievement in the actuarial science major. The paper includes a discussion of how these decisions might be applied in the context of a new actuarial program.

Sex, Income, and Achievement: Reward-Dualism in Academia.

ERIC Educational Resources Information Center

Fox, Mary Frank

A report is presented on an analysis of sex factors in academic income variation as determined by achieved, ascribed, and university location characteristics. The study group consisted of 5450 individuals at a major midwestern university as of June 1971. The subjects included 4541 men and 908 women research assistants and associates, deans and…

School Climate and Academic Achievement in Suburban Schools

ERIC Educational Resources Information Center

Sulak, Tracey N.

2016-01-01

School climate research has indicated a relationship between the climate of a school and academic achievement. The majority of explanatory models have been developed in urban schools with less attention given to suburban schools. Due to the process of formation of suburban schools, there is a likelihood these campuses differ from the traditional…

Women and Mathematics: Research vs. Achievement in Education.

ERIC Educational Resources Information Center

Abel, Theodora Mead; And Others

Many educators and researchers who believe that girls have less mathematical ability than boys associate this deficiency with girls' inferior spatial ability. This generally accepted belief that spatial skills are a major prerequisite for math achievement was tested through a study of the visual-spatial skills of a sample of 32 professional…

Baneful Effects of Social Crises on Adult Education Goals' Achievement in Nigeria

ERIC Educational Resources Information Center

Ogundele, Michael Olarewaju

2014-01-01

This study examined the baneful effects of social crisis on goals achievement of adult education in Nigeria. The study however described the concepts, types causes and impacts of social crisis in Nigeria. The study went further to examine the major indicators of Adult education goals achievement and how the social crisis affects effective goals…

[Molecular Biology for Surgical Treatment of Lung Cancer].

PubMed

Suda, Kenichi; Mitsudomi, Tetsuya

2017-01-01

Progress in lung cancer research achieved during the last 10 years was summarized. These include identification of novel driver mutations and application of targeted therapies, resistance mechanisms to targeted therapies, and immunotherapy with immune checkpoint inhibitors. Molecular biology also affects the field of surgical treatment. Several molecular markers have been reported to predict benign/ malignant or stable/growing tumors, although far from clinical application. In perioperative period, there is a possibility of atrial natriuretic peptide to prevent cancer metastasis. As adjuvant settings, although biomarker-based cytotoxic therapies failed to show clinical efficacy, several trials are ongoing employing molecular targeted agents (EGFR-TKI or ALK-TKI) or immune checkpoint inhibitors. In clinical practice, mutational information is sometimes used to distinguish 2nd primary tumors from pulmonary metastases of previous cancers. Surgery also has important role for oligo-progressive disease during molecular targeted therapies.

EDITORIAL: Molecular switches at surfaces Molecular switches at surfaces

NASA Astrophysics Data System (ADS)

Weinelt, Martin; von Oppen, Felix

2012-10-01

In nature, molecules exploit interaction with their environment to realize complex functionalities on the nanometer length scale. Physical, chemical and/or biological specificity is frequently achieved by the switching of molecules between microscopically different states. Paradigmatic examples are the energy production in proton pumps of bacteria or the signal conversion in human vision, which rely on switching molecules between different configurations or conformations by external stimuli. The remarkable reproducibility and unparalleled fatigue resistance of these natural processes makes it highly desirable to emulate nature and develop artificial systems with molecular functionalities. A promising avenue towards this goal is to anchor the molecular switches at surfaces, offering new pathways to control their functional properties, to apply electrical contacts, or to integrate switches into larger systems. Anchoring at surfaces allows one to access the full range from individual molecular switches to self-assembled monolayers of well-defined geometry and to customize the coupling between molecules and substrate or between adsorbed molecules. Progress in this field requires both synthesis and preparation of appropriate molecular systems and control over suitable external stimuli, such as light, heat, or electrical currents. To optimize switching and generate function, it is essential to unravel the geometric structure, the electronic properties and the dynamic interactions of the molecular switches on surfaces. This special section, Molecular Switches at Surfaces, collects 17 contributions describing different aspects of this research field. They analyze elementary processes, both in single molecules and in ensembles of molecules, which involve molecular switching and concomitant changes of optical, electronic, or magnetic properties. Two topical reviews summarize the current status, including both challenges and achievements in the field of molecular switches on

Genetics and Molecular Pathogenesis of Gastric Adenocarcinoma.

PubMed

Tan, Patrick; Yeoh, Khay-Guan

2015-10-01

Gastric cancer (GC) is globally the fifth most common cancer and third leading cause of cancer death. A complex disease arising from the interaction of environmental and host-associated factors, key contributors to GC's high mortality include its silent nature, late clinical presentation, and underlying biological and genetic heterogeneity. Achieving a detailed molecular understanding of the various genomic aberrations associated with GC will be critical to improving patient outcomes. The recent years has seen considerable progress in deciphering the genomic landscape of GC, identifying new molecular components such as ARID1A and RHOA, cellular pathways, and tissue populations associated with gastric malignancy and progression. The Cancer Genome Atlas (TCGA) project is a landmark in the molecular characterization of GC. Key challenges for the future will involve the translation of these molecular findings to clinical utility, by enabling novel strategies for early GC detection, and precision therapies for individual GC patients. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

UNEP: Two Decades of Achievement and Challenge. 20 Years.

ERIC Educational Resources Information Center

El-Hinnawi, Essam

This publication highlights major achievements of the United Nations Environment Program (UNEP) activities over the period 1970 to 1990. Chapter 1, "The Stockholm Conference and the Establishment of UNEP," describes the establishment of UNEP. Chapter 2, "The Role of UNEP," covers program development, environment and…

Experimental thermodynamics of single molecular motor.

PubMed

Toyabe, Shoichi; Muneyuki, Eiro

2013-01-01

Molecular motor is a nano-sized chemical engine that converts chemical free energy to mechanical motions. Hence, the energetics is as important as kinetics in order to understand its operation principle. We review experiments to evaluate the thermodynamic properties of a rotational F1-ATPase motor (F1-motor) at a single-molecule level. We show that the F1-motor achieves 100% thermo dynamic efficiency at the stalled state. Furthermore, the motor reduces the internal irreversible heat inside the motor to almost zero and achieves a highly-efficient free energy transduction close to 100% during rotations far from quasistatic process. We discuss the mechanism of how the F1-motor achieves such a high efficiency, which highlights the remarkable property of the nano-sized engine F1-motor.

Experimental thermodynamics of single molecular motor

PubMed Central

Toyabe, Shoichi; Muneyuki, Eiro

2013-01-01

Molecular motor is a nano-sized chemical engine that converts chemical free energy to mechanical motions. Hence, the energetics is as important as kinetics in order to understand its operation principle. We review experiments to evaluate the thermodynamic properties of a rotational F1-ATPase motor (F1-motor) at a single-molecule level. We show that the F1-motor achieves 100% thermo dynamic efficiency at the stalled state. Furthermore, the motor reduces the internal irreversible heat inside the motor to almost zero and achieves a highly-efficient free energy transduction close to 100% during rotations far from quasistatic process. We discuss the mechanism of how the F1-motor achieves such a high efficiency, which highlights the remarkable property of the nano-sized engine F1-motor. PMID:27493546

Kernel approach to molecular similarity based on iterative graph similarity.

PubMed

Rupp, Matthias; Proschak, Ewgenij; Schneider, Gisbert

2007-01-01

Similarity measures for molecules are of basic importance in chemical, biological, and pharmaceutical applications. We introduce a molecular similarity measure defined directly on the annotated molecular graph, based on iterative graph similarity and optimal assignments. We give an iterative algorithm for the computation of the proposed molecular similarity measure, prove its convergence and the uniqueness of the solution, and provide an upper bound on the required number of iterations necessary to achieve a desired precision. Empirical evidence for the positive semidefiniteness of certain parametrizations of our function is presented. We evaluated our molecular similarity measure by using it as a kernel in support vector machine classification and regression applied to several pharmaceutical and toxicological data sets, with encouraging results.

Training New Technologists in the Basics of Molecular Pathology.

ERIC Educational Resources Information Center

Matta, Nahida

1993-01-01

Outlines a training model designed to help senior technologists ensure that the newly hired technologists in the clinical molecular pathology laboratory achieve the minimum level of knowledge needed to perform and progress on the job. (Author)

Three Dopaminergic Polymorphisms Are Associated with Academic Achievement in Middle and High School

ERIC Educational Resources Information Center

Beaver, Kevin M.; Vaughn, Michael G.; Wright, John Paul; DeLisi, Matt; Howard, Matthew O.

2010-01-01

Although academic achievement is a heritable construct, to date research has yet to explore its molecular genetic underpinnings. Drawing on data from the National Longitudinal Study of Adolescent Health, the current longitudinal study investigated the associations between polymorphisms in three dopaminergic genes (DAT1, DRD2, and DRD4) and…

Committee on Atomic, Molecular and Optical Sciences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lancaster, James

The Committee on Atomic, Molecular, and Optical Sciences (CAMOS) is a standing activity of the National Research Council (NRC) that operates under the auspices of the Board on Physics and Astronomy. CAMOS is one of five standing committees of the BPA that are charged with assisting it in achieving its goals—monitoring the health of physics and astronomy, identifying important new developments at the scientific forefronts, fostering interactions with other fields, strengthening connections to technology, facilitating effective service to the nation, and enhancing education in physics. CAMOS provides these capabilities for the atomic, molecular and optical (AMO) sciences.

Bioinformatic Integration of Molecular Networks and Major Pathways Involved in Mice Cochlear and Vestibular Supporting Cells.

PubMed

Requena, Teresa; Gallego-Martinez, Alvaro; Lopez-Escamez, Jose A

2018-01-01

Background : Cochlear and vestibular epithelial non-hair cells (ENHCs) are the supporting elements of the cellular architecture in the organ of Corti and the vestibular neuroepithelium in the inner ear. Intercellular and cell-extracellular matrix interactions are essential to prevent an abnormal ion redistribution leading to hearing and vestibular loss. The aim of this study is to define the main pathways and molecular networks in the mouse ENHCs. Methods : We retrieved microarray and RNA-seq datasets from mouse epithelial sensory and non-sensory cells from gEAR portal (http://umgear.org/index.html) and obtained gene expression fold-change between ENHCs and non-epithelial cells (NECs) against HCs for each gene. Differentially expressed genes (DEG) with a log2 fold change between 1 and -1 were discarded. The remaining genes were selected to search for interactions using Ingenuity Pathway Analysis and STRING platform. Specific molecular networks for ENHCs in the cochlea and the vestibular organs were generated and significant pathways were identified. Results : Between 1723 and 1559 DEG were found in the mouse cochlear and vestibular tissues, respectively. Six main pathways showed enrichment in the supporting cells in both tissues: (1) "Inhibition of Matrix Metalloproteases"; (2) "Calcium Transport I"; (3) "Calcium Signaling"; (4) "Leukocyte Extravasation Signaling"; (5) "Signaling by Rho Family GTPases"; and (6) "Axonal Guidance Si". In the mouse cochlea, ENHCs showed a significant enrichment in 18 pathways highlighting "axonal guidance signaling (AGS)" ( p = 4.37 × 10 -8 ) and "RhoGDI Signaling" ( p = 3.31 × 10 -8 ). In the vestibular dataset, there were 20 enriched pathways in ENHCs, the most significant being "Leukocyte Extravasation Signaling" ( p = 8.71 × 10 -6 ), "Signaling by Rho Family GTPases" ( p = 1.20 × 10 -5 ) and "Calcium Signaling" ( p = 1.20 × 10 -5 ). Among the top ranked networks, the most biologically significant network contained the

Comparative molecular cytogenetics of major repetitive sequence families of three Dendrobium species (Orchidaceae) from Bangladesh

PubMed Central

Begum, Rabeya; Alam, Sheikh Shamimul; Menzel, Gerhard; Schmidt, Thomas

2009-01-01

Background and Aims Dendrobium species show tremendous morphological diversity and have broad geographical distribution. As repetitive sequence analysis is a useful tool to investigate the evolution of chromosomes and genomes, the aim of the present study was the characterization of repetitive sequences from Dendrobium moschatum for comparative molecular and cytogenetic studies in the related species Dendrobium aphyllum, Dendrobium aggregatum and representatives from other orchid genera. Methods In order to isolate highly repetitive sequences, a c0t-1 DNA plasmid library was established. Repeats were sequenced and used as probes for Southern hybridization. Sequence divergence was analysed using bioinformatic tools. Repetitive sequences were localized along orchid chromosomes by fluorescence in situ hybridization (FISH). Key Results Characterization of the c0t-1 library resulted in the detection of repetitive sequences including the (GA)n dinucleotide DmoO11, numerous Arabidopsis-like telomeric repeats and the highly amplified dispersed repeat DmoF14. The DmoF14 repeat is conserved in six Dendrobium species but diversified in representative species of three other orchid genera. FISH analyses showed the genome-wide distribution of DmoF14 in D. moschatum, D. aphyllum and D. aggregatum. Hybridization with the telomeric repeats demonstrated Arabidopsis-like telomeres at the chromosome ends of Dendrobium species. However, FISH using the telomeric probe revealed two pairs of chromosomes with strong intercalary signals in D. aphyllum. FISH showed the terminal position of 5S and 18S–5·8S–25S rRNA genes and a characteristic number of rDNA sites in the three Dendrobium species. Conclusions The repeated sequences isolated from D. moschatum c0t-1 DNA constitute major DNA families of the D. moschatum, D. aphyllum and D. aggregatum genomes with DmoF14 representing an ancient component of orchid genomes. Large intercalary telomere-like arrays suggest chromosomal

Molecular Imaging of the Kidneys

PubMed Central

Szabo, Zsolt; Alachkar, Nada; Xia, Jinsong; Mathews, William B.; Rabb, Hamid

2010-01-01

Radionuclide imaging of the kidneys with gamma cameras involves the use of labeled molecules seeking functionally critical molecular mechanisms in order to detect the pathophysiology of the diseased kidneys and achieve an early, sensitive and accurate diagnosis. The most recent imaging technology, PET, permits quantitative imaging of the kidney at a spatial resolution appropriate for the organ. H215O, 82RbCl, and [64Cu] ETS are the most important radiopharmaceuticals for measuring renal blood flow. The renin angiotensin system is the most important regulator of renal blood flow; this role is being interrogated by detecting angiotensin receptor subtype AT1R using in vivo PET imaging. Membrane organic anion transporters are important for the function of the tubular epithelium; therefore, Tc-99m MAG3 as well as some novel radiopharmaceuticals such as copper-64 labeled mono oxo-tetraazamacrocyclic ligands have been utilized for molecular renal imaging. Additionally, other radioligands that interact with the organic cation transporters or peptide transporters have developed. Focusing on early detection of kidney injury at the molecular level is an evolving field of great significance. Potential imaging targets are the kidney injury molecule- 1 (KIM-1) that is highly expressed in kidney injury and renal cancer but not in normal kidneys. While pelvic clearance, in addition to parenchymal transport, is an important measure in obstructive nephropathy, techniques that focus on upregulated molecules in response to tissue stress resulted from obstruction will be of great implication. Monocyte chemoattractant protein -1 (MCP-1) is a well-suited molecule in this case. The greatest advances in molecular imaging of the kidneys have been recently achieved in detecting renal cancer. In addition to the ubiquitous [18F]FDG, other radioligands such as [11C]acetate and anti-[18F]FACBC have emerged. Radioimmuno-imaging with [124I]G250 could lead to radioimmunotherapy for renal cancer

Competence and Elementary School Achievement: Case Studies in an Urban Ghetto. Research Report, Vol. 4, No. 7.

ERIC Educational Resources Information Center

Hirsch, Jay G; Costello, Joan

This paper has presented some of the major conclusions arising out of a clinical study of a group of fifth grade achievers and underachievers from an urban lower class Negro public elementary school. The major factors which distinguished the group of achievers from the group of underachievers were those in the area of quality of interpersonal…

Graph Kernels for Molecular Similarity.

PubMed

Rupp, Matthias; Schneider, Gisbert

2010-04-12

Molecular similarity measures are important for many cheminformatics applications like ligand-based virtual screening and quantitative structure-property relationships. Graph kernels are formal similarity measures defined directly on graphs, such as the (annotated) molecular structure graph. Graph kernels are positive semi-definite functions, i.e., they correspond to inner products. This property makes them suitable for use with kernel-based machine learning algorithms such as support vector machines and Gaussian processes. We review the major types of kernels between graphs (based on random walks, subgraphs, and optimal assignments, respectively), and discuss their advantages, limitations, and successful applications in cheminformatics. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Does achievement motivation mediate the semantic achievement priming effect?

PubMed

Engeser, Stefan; Baumann, Nicola

2014-10-01

The aim of our research was to understand the processes of the prime-to-behavior effects with semantic achievement primes. We extended existing models with a perspective from achievement motivation theory and additionally used achievement primes embedded in the running text of excerpts of school textbooks to simulate a more natural priming condition. Specifically, we proposed that achievement primes affect implicit achievement motivation and conducted pilot experiments and 3 main experiments to explore this proposition. We found no reliable positive effect of achievement primes on implicit achievement motivation. In light of these findings, we tested whether explicit (instead of implicit) achievement motivation is affected by achievement primes and found this to be the case. In the final experiment, we found support for the assumption that higher explicit achievement motivation implies that achievement priming affects the outcome expectations. The implications of the results are discussed, and we conclude that primes affect achievement behavior by heightening explicit achievement motivation and outcome expectancies.

Comparative molecular cytogenetic analyses of a major tandemly repeated DNA family and retrotransposon sequences in cultivated jute Corchorus species (Malvaceae).

PubMed

Begum, Rabeya; Zakrzewski, Falk; Menzel, Gerhard; Weber, Beatrice; Alam, Sheikh Shamimul; Schmidt, Thomas

2013-07-01

The cultivated jute species Corchorus olitorius and Corchorus capsularis are important fibre crops. The analysis of repetitive DNA sequences, comprising a major part of plant genomes, has not been carried out in jute but is useful to investigate the long-range organization of chromosomes. The aim of this study was the identification of repetitive DNA sequences to facilitate comparative molecular and cytogenetic studies of two jute cultivars and to develop a fluorescent in situ hybridization (FISH) karyotype for chromosome identification. A plasmid library was generated from C. olitorius and C. capsularis with genomic restriction fragments of 100-500 bp, which was complemented by targeted cloning of satellite DNA by PCR. The diversity of the repetitive DNA families was analysed comparatively. The genomic abundance and chromosomal localization of different repeat classes were investigated by Southern analysis and FISH, respectively. The cytosine methylation of satellite arrays was studied by immunolabelling. Major satellite repeats and retrotransposons have been identified from C. olitorius and C. capsularis. The satellite family CoSat I forms two undermethylated species-specific subfamilies, while the long terminal repeat (LTR) retrotransposons CoRetro I and CoRetro II show similarity to the Metaviridea of plant retroelements. FISH karyotypes were developed by multicolour FISH using these repetitive DNA sequences in combination with 5S and 18S-5·8S-25S rRNA genes which enable the unequivocal chromosome discrimination in both jute species. The analysis of the structure and diversity of the repeated DNA is crucial for genome sequence annotation. The reference karyotypes will be useful for breeding of jute and provide the basis for karyotyping homeologous chromosomes of wild jute species to reveal the genetic and evolutionary relationship between cultivated and wild Corchorus species.

Comparative molecular cytogenetic analyses of a major tandemly repeated DNA family and retrotransposon sequences in cultivated jute Corchorus species (Malvaceae)

PubMed Central

Begum, Rabeya; Zakrzewski, Falk; Menzel, Gerhard; Weber, Beatrice; Alam, Sheikh Shamimul; Schmidt, Thomas

2013-01-01

Background and Aims The cultivated jute species Corchorus olitorius and Corchorus capsularis are important fibre crops. The analysis of repetitive DNA sequences, comprising a major part of plant genomes, has not been carried out in jute but is useful to investigate the long-range organization of chromosomes. The aim of this study was the identification of repetitive DNA sequences to facilitate comparative molecular and cytogenetic studies of two jute cultivars and to develop a fluorescent in situ hybridization (FISH) karyotype for chromosome identification. Methods A plasmid library was generated from C. olitorius and C. capsularis with genomic restriction fragments of 100–500 bp, which was complemented by targeted cloning of satellite DNA by PCR. The diversity of the repetitive DNA families was analysed comparatively. The genomic abundance and chromosomal localization of different repeat classes were investigated by Southern analysis and FISH, respectively. The cytosine methylation of satellite arrays was studied by immunolabelling. Key Results Major satellite repeats and retrotransposons have been identified from C. olitorius and C. capsularis. The satellite family CoSat I forms two undermethylated species-specific subfamilies, while the long terminal repeat (LTR) retrotransposons CoRetro I and CoRetro II show similarity to the Metaviridea of plant retroelements. FISH karyotypes were developed by multicolour FISH using these repetitive DNA sequences in combination with 5S and 18S–5·8S–25S rRNA genes which enable the unequivocal chromosome discrimination in both jute species. Conclusions The analysis of the structure and diversity of the repeated DNA is crucial for genome sequence annotation. The reference karyotypes will be useful for breeding of jute and provide the basis for karyotyping homeologous chromosomes of wild jute species to reveal the genetic and evolutionary relationship between cultivated and wild Corchorus species. PMID:23666888

Immunological and molecular polymorphisms of OspC, an immunodominant major outer surface protein of Borrelia burgdorferi.

PubMed Central

Wilske, B; Preac-Mursic, V; Jauris, S; Hofmann, A; Pradel, I; Soutschek, E; Schwab, E; Will, G; Wanner, G

1993-01-01

The gene of the immunodominant major protein pC of Borrelia burgdorferi was previously cloned and sequenced (R. Fuchs, S. Jauris, F. Lottspeich, V. Preac-Mursic, B. Wilske, and E. Soutschek, Mol. Microbiol. 6:503-509, 1992). pC is abundantly expressed on the outer surface of B. burgdorferi, as demonstrated by immunoelectron microscopy with monoclonal antibody L22 1F8. Accordingly, pC is renamed OspC, by analogy to the outer surface proteins OspA and OspB. Western immunoblot analysis of 45 B. burgdorferi isolates with monoclonal antibodies revealed that OspC is immunologically heterogeneous. Partial sequence analysis of the ospC gene confirmed the protein heterogeneity at the genetic level. We found that the degree of identity between the ospC partial sequences of five strains representing different OspA serotypes was only 63.3 to 85.4%. Immunological heterogeneity was also observed among representatives of the three newly designated genospecies of B. burgdorferi sensu lato, B. burgdorferi sensu stricto, B. garinii, and group VS461. Heterogeneity was confirmed for B. garinii at the genetic level. The ospC gene was also cloned from strains that did not express OspC, and antibody-reactive OspC was expressed in Escherichia coli. In addition, OspC-expressing variants were obtained from a nonexpressing strain by plating single colonies on solid medium. These findings confirm that the ospC gene is also present in nonexpressing strains. Because OspC is an immunodominant protein for the early immune response in Lyme borreliosis and was effective as a vaccine in an animal model, the immunological and molecular polymorphisms of ospC and OspC have important implications for the development of diagnostic reagents and vaccines. Images PMID:8478108

Vertical resonant tunneling transistors with molecular quantum dots for large-scale integration.

PubMed

Hayakawa, Ryoma; Chikyow, Toyohiro; Wakayama, Yutaka

2017-08-10

Quantum molecular devices have a potential for the construction of new data processing architectures that cannot be achieved using current complementary metal-oxide-semiconductor (CMOS) technology. The relevant basic quantum transport properties have been examined by specific methods such as scanning probe and break-junction techniques. However, these methodologies are not compatible with current CMOS applications, and the development of practical molecular devices remains a persistent challenge. Here, we demonstrate a new vertical resonant tunneling transistor for large-scale integration. The transistor channel is comprised of a MOS structure with C 60 molecules as quantum dots, and the structure behaves like a double tunnel junction. Notably, the transistors enabled the observation of stepwise drain currents, which originated from resonant tunneling via the discrete molecular orbitals. Applying side-gate voltages produced depletion layers in Si substrates, to achieve effective modulation of the drain currents and obvious peak shifts in the differential conductance curves. Our device configuration thus provides a promising means of integrating molecular functions into future CMOS applications.

An antilock molecular braking system.

PubMed

Sun, Wei-Ting; Huang, Shou-Ling; Yao, Hsuan-Hsiao; Chen, I-Chia; Lin, Ying-Chih; Yang, Jye-Shane

2012-08-17

A light-driven molecular brake displaying an antilock function is constructed by introducing a nonradiative photoinduced electron transfer (PET) decay channel to compete with the trans (brake-off) → cis (brake-on) photoisomerization. A fast release of the brake can be achieved by deactivating the PET process through addition of protons. The cycle of irradiation-protonation-irradiation-deprotonation conducts the brake function and mimics the antilock braking system (ABS) of vehicles.

Correlates of midlife career achievement among women physicians.

PubMed

Graves, P L; Thomas, C B

1985-08-09

In the context of a longitudinal study, we explored factors contributing to midlife career achievement among 108 women physicians. Three groups were formed, based on medical specialty, specialty board certification, and professorial appointment. Using analysis of variance procedures, the career groups were compared on measures obtained during medical school and on marital status, family size, and three health measures in midlife. Of the youthful measures, academic standing, father's socioeconomic status, and early family (specifically father-daughter) relationships were found to be associated with midlife achievement. Furthermore, a clear association was observed between success and good health in midlife. Married women formed the majority in all groups; no differences in family size were found. We conclude that career achievement among women physicians is influenced less by marriage and family size than by motivational and personality factors shaped in early life.

A PLAN FOR EVALUATING MAJOR ACTIVITIES IN GREAT CITIES SCHOOL IMPROVEMENT PROGRAM.

ERIC Educational Resources Information Center

MARBURGER, CARL L.; RASSCHAERT, WILLIAM M.

THE GUIDE IS INTENDED TO ASSIST PROJECT DIRECTORS IN THEIR EFFORTS TO DEVELOP MORE SYSTEMATIC AND THOROUGH EVALUATION DESIGNS FOR THE GREAT CITIES SCHOOL IMPROVEMENT PROGRAM. MAJOR DIMENSIONS OF TEACHING-LEARNING, SCHOOL-COMMUNITY, AND PUPIL-PARENT-TEACHER ACTIVITIES ARE LISTED. MAJOR EVALUATION AREAS ARE IN PUPIL ACHIEVEMENT, IMPLEMENTED BY GROUP…

Deep molecular responses for treatment-free remission in chronic myeloid leukemia.

PubMed

Dulucq, Stéphanie; Mahon, Francois-Xavier

2016-09-01

Several clinical trials have demonstrated that some patients with chronic myeloid leukemia in chronic phase (CML-CP) who achieve sustained deep molecular responses on tyrosine kinase inhibitor (TKI) therapy can safely suspend therapy and attempt treatment-free remission (TFR). Many TFR studies to date have enrolled imatinib-treated patients; however, the feasibility of TFR following nilotinib or dasatinib has also been demonstrated. In this review, we discuss available data from TFR trials and what these data reveal about the molecular biology of TFR. With an increasing number of ongoing TFR clinical trials, TFR may become an achievable goal for patients with CML-CP. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Gamma-glutamylcysteine and thiosulfate are the major low-molecular-weight thiols in halobacteria

NASA Technical Reports Server (NTRS)

Newton, Gerald L.; Javor, Barbara

1985-01-01

Six representative species of extremely halophilic bacteria were found to contain approximately millimolar concentrations of gamma-glutamylcysteine in the absence of significant glutathione. Thiosulfate also accumulated in the halobacteria, apparently as a major product of cysteine oxidation.

Molecular pathways and therapeutic targets in lung cancer

PubMed Central

Shtivelman, Emma; Hensing, Thomas; Simon, George R.; Dennis, Phillip A.; Otterson, Gregory A.; Bueno, Raphael; Salgia, Ravi

2014-01-01

Lung cancer is still the leading cause of cancer death worldwide. Both histologically and molecularly lung cancer is heterogeneous. This review summarizes the current knowledge of the pathways involved in the various types of lung cancer with an emphasis on the clinical implications of the increasing number of actionable molecular targets. It describes the major pathways and molecular alterations implicated in the development and progression of non-small cell lung cancer (adenocarcinoma and squamous cancer), and of small cell carcinoma, emphasizing the molecular alterations comprising the specific blueprints in each group. The approved and investigational targeted therapies as well as the immune therapies, and clinical trials exploring the variety of targeted approaches to treatment of lung cancer are the main focus of this review. PMID:24722523

Neurobiology of Chronic Stress-Related Psychiatric Disorders: Evidence from Molecular Imaging Studies

PubMed Central

Davis, Margaret T.; Holmes, Sophie E.; Pietrzak, Robert H.; Esterlis, Irina

2018-01-01

Chronic stress accounts for billions of dollars of economic loss annually in the United States alone, and is recognized as a major source of disability and mortality worldwide. Robust evidence suggests that chronic stress plays a significant role in the onset of severe and impairing psychiatric conditions, including major depressive disorder, bipolar disorder, and posttraumatic stress disorder. Application of molecular imaging techniques such as positron emission tomography and single photon emission computed tomography in recent years has begun to provide insight into the molecular mechanisms by which chronic stress confers risk for these disorders. The present paper provides a comprehensive review and synthesis of all positron emission tomography and single photon emission computed tomography imaging publications focused on the examination of molecular targets in individuals with major depressive disorder, posttraumatic stress disorder, or bipolar disorder to date. Critical discussion of discrepant findings and broad strengths and weaknesses of the current body of literature is provided. Recommended future directions for the field of molecular imaging to further elucidate the neurobiological substrates of chronic stress-related disorders are also discussed. This article is part of the inaugural issue for the journal focused on various aspects of chronic stress. PMID:29862379

The Determinants of School Achievement in Developing Countries: A Review of the Research.

ERIC Educational Resources Information Center

Simmons, John; Alexander, Leigh

The goal of the review is to identify the factors which promote student cognitive achievement as measured by several studies conducted in developing countries. The major tool of analysis which measures the relationship between the school inputs, like teacher quality and school facilities, and cognitive achievement is the educational production…

Association of HLA-DR1 with the allergic response to the major mugwort pollen allergen: molecular background.

PubMed

Knapp, Bernhard; Fischer, Gottfried; Van Hemelen, Dries; Fae, Ingrid; Maillere, Bernard; Ebner, Christof; Schreiner, Wolfgang; Bohle, Barbara; Jahn-Schmid, Beatrice

2012-08-08

Mugwort pollen allergens represent the main cause of pollinosis in late summer. The major allergen, Art v 1, contains only one single immunodominant, solely HLA-DR-restricted T cell epitope (Art v 125-36). The frequency of HLA-DRB1*01 is highly increased in mugwort-allergic individuals and HLA-DR1 serves as restriction element for Art v 125-36. However, Art v 125-36 also binds to HLA-DR4 with high affinity and DR1-restricted Art v 125-36 -specific T cell receptors can be activated by HLA-DR4 molecules. To understand the predominance of HLA-DR1 in mugwort allergy in spite of the degeneracy in HLA/peptide-binding and TCR-recognition, we investigated the molecular background of Art v 125-36 /MHC/TCR interactions in the context of HLA-DR1 compared to -DR4. The majority of Art v 125-36 -specific T cell lines and clones from HLA-DR1 carrying, mugwort pollen-allergic donors reacted to synthetic and naturally processed Art v 1-peptides when presented by HLA-DR1 or HLA-DR4 expressing antigen presenting cells. However, at limiting peptide concentrations DR1 was more effective in T cell stimulation. In addition, the minimal epitope for 50% of Art v 125-36 -specific T cells was shorter for DR1 than for DR4. In vitro binding assays of Art v 125-36 mutant peptides to isolated DR1- and DR4-molecules indicated similar binding capacities and use of the same register. In silico simulation of Art v 125-36 binding to HLA-DR1 and -DR4 suggested similar binding of the central part of the peptide to either molecule, but a higher flexibility of the N- and C-terminal amino acids and detachment at the C-terminus in HLA-DR1. The predominance of HLA-DR1 in the response to Art v 125-36 may be explained by subtle conformation changes of the peptide bound to DR1 compared to DR4. Computer simulation supported our experimental data by demonstrating differences in peptide mobility within the HLA-DR complex that may influence TCR-binding. We suggest that the minor differences observed in vitro may

Molecular Modeling and Structural Stability of Wild-Type and Mutant CYP51 from Leishmania major: In Vitro and In Silico Analysis of a Laboratory Strain.

PubMed

Keighobadi, Masoud; Emami, Saeed; Lagzian, Milad; Fakhar, Mahdi; Rafiei, Alireza; Valadan, Reza

2018-03-19

Cutaneous leishmaniasis is a neglected tropical disease and a major public health in the most countries. Leishmania major is the most common cause of cutaneous leishmaniasis. In the Leishmania parasites, sterol 14α-demethylase (CYP51), which is involved in the biosynthesis of sterols, has been identified as an attractive target for development of new therapeutic agents. In this study, the sequence and structure of CYP51 in a laboratory strain (MRHO/IR/75/ER) of L. major were determined and compared to the wild-type strain. The results showed 19 mutations including seven non-synonymous and 12 synonymous ones in the CYP51 sequence of strain MRHO/IR/75/ER. Importantly, an arginine to lysine substitution at position of 474 resulted in destabilization of CYP51 (ΔΔG = 1.17 kcal/mol) in the laboratory strain; however, when the overall effects of all substitutions were evaluated by 100 ns molecular dynamics simulation, the final structure did not show any significant changes ( p -value < 0.05) in stability parameter of the strain MRHO/IR/75/ER compared to the wild-type protein. The energy level for the CYP51 of wild-type and MRHO/IR/75/ER strain were -40,027.1 and -39,706.48 Kcal/mol respectively. The overall Root-mean-square deviation (RMSD) deviation between two proteins was less than 1 Å throughout the simulation and Root-mean-square fluctuation (RMSF) plot also showed no substantial differences between amino acids fluctuation of the both protein. The results also showed that, these mutations were located on the protein periphery that neither interferes with protein folding nor with substrate/inhibitor binding. Therefore, L. major strain MRHO/IR/75/ER is suggested as a suitable laboratory model for studying biological role of CYP51 and inhibitory effects of sterol 14α-demethylase inhibitors.

40 CFR 63.42 - Program requirements governing construction or reconstruction of major sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... construction or reconstruction of major sources. 63.42 Section 63.42 Protection of Environment ENVIRONMENTAL... POLLUTANTS FOR SOURCE CATEGORIES Requirements for Control Technology Determinations for Major Sources in... achievable control technology emission limitation for new sources. [61 FR 68400, Dec. 27, 1996, as amended at...

Achievement Goals and Achievement Emotions: A Meta-Analysis

ERIC Educational Resources Information Center

Huang, Chiungjung

2011-01-01

This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

Electron Transport Modeling of Molecular Nanoscale Bridges Used in Energy Conversion Schemes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunietz, Barry D

2016-08-09

The goal of the research program is to reliably describe electron transport and transfer processes at the molecular level. Such insight is essential for improving molecular applications of solar and thermal energy conversion. We develop electronic structure models to study (1) photoinduced electron transfer and transport processes in organic semiconducting materials, and (2) charge and heat transport through molecular bridges. We seek fundamental understanding of key processes, which lead to design new experiments and ultimately to achieve systems with improved properties.

A comparison of students' achievement and attitude as a function of lecture/lab sequencing in a non-science majors introductory biology course

NASA Astrophysics Data System (ADS)

Hurst March, Robin Denise

This investigation compared student achievement and attitudes toward science from three different sequencing approaches used in teaching biology to nonscience students. The three sequencing approaches were the lecture course only, lecture/laboratory courses taken together, and laboratory with previously taken lecture approach. The purposes of this study were to determine if (1) a relationship exists between the Attitude Towards Science in School Assessment (ATSSA) scores (Germann, 1988) and biology achievement, (2) a difference exists among the ATSSA scores and sequencing, (3) a difference exists among the biology achievement scores and sequencing, and (4) the ATSSA is a reliable instrument of science attitude assessment for the undergraduate students in an introductory biology nonmajors laboratory and lecture courses at a research I institution during the fall semester 1996. Fifty-four students comprised the lecture only group, 90 students comprised the lecture and laboratory taken together approach, and 23 students comprised the laboratory only approach. Research questions addressed were (1) What are the differences in student biology achievement as a function of the three different methods of instruction? (2) What are the differences in student attitude towards science as a function of the three different methods of instruction? (3) What is the relationship between post-attitude (ATSSA) and biology achievement for each of the three methods of instruction? An analysis of variance utilized the mean posttest scores on the ATSSA and mean achievement scores as the dependent variables. The independent variables were the three different sequences of enrollment in introductory biology. At the.05 level of significance, it was found that no significant difference existed between the ATTS and laboratory/lecture sequence. At the.05 level of significance, it was found that no significant difference existed between achievement and laboratory/lecture sequence. A Pearson

The Ten Outstanding Engineering Achievements of the Past 50 Years.

ERIC Educational Resources Information Center

Hightower, George

1984-01-01

Describes the outstanding achievement in each of 10 major engineering categories. These categories include synthetic fibers, nuclear energy, computers, solid state electronics, jet aircraft, biomedical engineering, lasers, communications satellites, the United States space program, and automation and control systems. (JN)

What Attracts High-Achieving Socioeconomically Disadvantaged Students to the Physical Sciences and Engineering?

ERIC Educational Resources Information Center

Conrad, Sarah; Canetto, Silvia Sara; MacPhee, David; Farro, Samantha

2009-01-01

Socioeconomically disadvantaged (SED) students are less likely to major in physical sciences or engineering. To guide recruitment and retention of a diversity of talent, this study examined what attracts high-achieving SED students to these fields. Participants were 50 undergraduates majoring in physical sciences or engineering enrolled in the…

Molecular Detection of Leishmania major and L. turanica in Phlebotomus papatasi and First Natural Infection of P. salehi to L. major in North-East of Iran.

PubMed

Rafizadeh, Sayena; Saraei, Mehrzad; Abaei, Mohammad Reza; Oshaghi, Mohammad Ali; Mohebali, Mehdi; Peymani, Amir; Naserpour-Farivar, Taghi; Bakhshi, Hassan; Rassi, Yavar

2016-06-01

Leishmaniasis is an important public health disease in many developing countries as well in Iran. The main objective of this study was to investigate on leishmania infection of wild caught sand flies in an endemic focus of disease in Esfarayen district, north east of Iran. Sand flies were collected by sticky papers and mounted in a drop of Puri's medium for species identification. Polymerase chain reaction techniques of kDNA, ITS1-rDNA, followed by restriction fragment length polymorphism were used for identification of DNA of Leishmania parasites within infected sand flies. Among the collected female sand flies, two species of Phlebotomus papatasi and Phlebotomus salehi were found naturally infected with Leishmania major. Furthermore, mixed infection of Leishmania turanica and L. major was observed in one specimen of P. papatasi. Sequence analysis revealed two parasite ITS1 haplotypes including three L. major with accession numbers: KJ425408, KJ425407, KM056403 and one L. turanica. (KJ425406). The haplotype of L. major was identical (100%) to several L. major sequences deposited in GenBank, including isolates from Iran, (Gen Bank accession nos.AY573187, KC505421, KJ194178) and Uzbekistan (Accession no.FN677357). To our knowledge, this is the first detection of L. major within wild caught P. salehi in northeast of Iran.

Fine- and hyperfine-structure effects in molecular photoionization. II. Resonance-enhanced multiphoton ionization and hyperfine-selective generation of molecular cations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Germann, Matthias; Willitsch, Stefan, E-mail: stefan.willitsch@unibas.ch

2016-07-28

Resonance-enhanced multiphoton ionization (REMPI) is a widely used technique for studying molecular photoionization and producing molecular cations for spectroscopy and dynamics studies. Here, we present a model for describing hyperfine-structure effects in the REMPI process and for predicting hyperfine populations in molecular ions produced by this method. This model is a generalization of our model for fine- and hyperfine-structure effects in one-photon ionization of molecules presented in Paper I [M. Germann and S. Willitsch, J. Chem. Phys. 145, 044314 (2016)]. This generalization is achieved by covering two main aspects: (1) treatment of the neutral bound-bound transition including the hyperfine structuremore » that makes up the first step of the REMPI process and (2) modification of our ionization model to account for anisotropic populations resulting from this first excitation step. Our findings may be used for analyzing results from experiments with molecular ions produced by REMPI and may serve as a theoretical background for hyperfine-selective ionization experiments.« less

Relationship between affective determinants and achievement in science for seventeen-year-olds

NASA Astrophysics Data System (ADS)

Napier, John D.; Riley, Joseph P.

Data collected in the 1976-1977 NAEP survey of seventeen-year-olds was used to reanalyze the hypothesis that there are affective determinates of science achievement. Factor and item analysis procedures were used to examine affective and cognitive items from Booklet 4. Eight affective scales and one cognitive achievement scale were identified. Using stepwise multiple regression procedures, the four affective scales of Motivation, Anxiety, Student Choice, and Teacher Support were found to account for the majority of the correlation between the affective determinants and achievement.

Rotational spectroscopy of cold and trapped molecular ions in the Lamb-Dicke regime

NASA Astrophysics Data System (ADS)

Alighanbari, S.; Hansen, M. G.; Korobov, V. I.; Schiller, S.

2018-06-01

Sympathetic cooling of trapped ions has been established as a powerful technique for the manipulation of non-laser-coolable ions1-4. For molecular ions, it promises vastly enhanced spectroscopic resolution and accuracy. However, this potential remains untapped so far, with the best resolution achieved being not better than 5 × 10-8 fractionally, due to residual Doppler broadening being present in ion clusters even at the lowest achievable translational temperatures5. Here we introduce a general and accessible approach that enables Doppler-free rotational spectroscopy. It makes use of the strong radial spatial confinement of molecular ions when trapped and crystallized in a linear quadrupole trap, providing the Lamb-Dicke regime for rotational transitions. We achieve a linewidth of 1 × 10-9 fractionally and 1.3 kHz absolute, an improvement of ≃50-fold over the previous highest resolution in rotational spectroscopy. As an application, we demonstrate the most precise test of ab initio molecular theory and the most accurate (1.3 × 10-9) determination of the proton mass using molecular spectroscopy. The results represent the long overdue extension of Doppler-free microwave spectroscopy of laser-cooled atomic ion clusters6 to higher spectroscopy frequencies and to molecules. This approach enables a wide range of high-accuracy measurements on molecules, both on rotational and, as we project, vibrational transitions.

Adaptively restrained molecular dynamics in LAMMPS

NASA Astrophysics Data System (ADS)

Kant Singh, Krishna; Redon, Stephane

2017-07-01

Adaptively restrained molecular dynamics (ARMD) is a recently introduced particles simulation method that switches positional degrees of freedom on and off during simulation in order to speed up calculations. In the NVE ensemble, ARMD allows users to trade between precision and speed while, in the NVT ensemble, it makes it possible to compute statistical averages faster. Despite the conceptual simplicity of the approach, however, integrating it in existing molecular dynamics packages is non-trivial, in particular since implemented potentials should a priori be rewritten to take advantage of frozen particles and achieve a speed-up. In this paper, we present novel algorithms for integrating ARMD in LAMMPS, a popular multi-purpose molecular simulation package. In particular, we demonstrate how to enable ARMD in LAMMPS without having to re-implement all available force fields. The proposed algorithms are assessed on four different benchmarks, and show how they allow us to speed up simulations up to one order of magnitude.

Ring-through-ring molecular shuttling in a saturated [3]rotaxane

NASA Astrophysics Data System (ADS)

Zhu, Kelong; Baggi, Giorgio; Loeb, Stephen J.

2018-06-01

Mechanically interlocked molecules such as rotaxanes and catenanes comprise two or more components whose motion relative to each other can be controlled. A [2]rotaxane molecular shuttle, for example, consists of an axle bearing two recognition sites and a single macrocyclic wheel that can undergo a to-and-fro motion along the axle—shuttling between the recognition sites. The ability of mechanically interlocked molecules to undergo this type of large-amplitude change is the core mechanism behind almost every interlocked molecular switch or machine, including sophisticated mechanical systems such as a molecular elevator and a peptide synthesizer. Here, as a way to expand the scope of dynamics possible at the molecular level, we have developed a molecular shuttling mechanism involving the exchange of rings between two recognition sites in a saturated [3]rotaxane (one with no empty recognition sites). This was accomplished by passing a smaller ring through a larger one, thus achieving ring-through-ring molecular shuttling.

Major versus minor groove DNA binding of a bisarginylporphyrin hybrid molecule: A molecular mechanics investigation

NASA Astrophysics Data System (ADS)

Gresh, Nohad; Perrée-fauvet, Martine

1999-03-01

On the basis of theoretical computations, we have recently synthesised [Perrée-Fauvet, M. and Gresh, N., Tetrahedron Lett., 36 (1995) 4227] a bisarginyl conjugate of a tricationic porphyrin (BAP), designed to target, in the major groove of DNA, the d(GGC GCC)2 sequence which is part of the primary binding site of the HIV-1 retrovirus site [Wain-Hobson, S. et al., Cell, 40 (1985) 9]. In the theoretical model, the chromophore intercalates at the central d(CpG)2 step and each of the arginyl arms targets O6/N7belonging to guanine bases flanking the intercalation site. Recent IR and UV-visible spectroscopic studies have confirmed the essential features of these theoretical predictions [Mohammadi, S. et al., Biochemistry, 37 (1998) 6165]. In the present study, we compare the energies of competing intercalation modes of BAP to several double-stranded oligonucleotides, according to whether one, two or three N- methylpyridinium rings project into the major groove. Correspondingly, three minor groove binding modes were considered, the arginyl arms now targeting N3, O2 sites belonging to the purine or pyrimidine bases flanking the intercalation site. This investigation has shown that: (i) in both the major and minor grooves, the best-bound complexes have the three N-methylpyridinium rings in the groove opposite to that of the phenyl group bearing the arginyl arms; (ii) major groove binding is preferred over minor groove binding by a significant energy (29 kcal/mol); and (iii) the best-bound sequence in the major groove is d(GGC GCC)2 with two successive guanines upstream from the intercalation. On the other hand, due to the flexibility of the arginyl arms, other GC-rich sequences have close binding energies, two of them being less stable than it by less than 8 kcal/mol. These results serve as the basis for the design of derivatives of BAP with enhanced sequence selectivities in the major groove.

Switchable molecular magnets

PubMed Central

SATO, Osamu

2012-01-01

Various molecular magnetic compounds whose magnetic properties can be controlled by external stimuli have been developed, including electrochemically, photochemically, and chemically tunable bulk magnets as well as a phototunable antiferromagnetic phase of single chain magnet. In addition, we present tunable paramagnetic mononuclear complexes ranging from spin crossover complexes and valence tautomeric complexes to Co complexes in which orbital angular momentum can be switched. Furthermore, we recently developed several switchable clusters and one-dimensional coordination polymers. The switching of magnetic properties can be achieved by modulating metals, ligands, and molecules/ions in the second sphere of the complexes. PMID:22728438

The effects of chronic achievement motivation and achievement primes on the activation of achievement and fun goals.

PubMed

Hart, William; Albarracín, Dolores

2009-12-01

This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit of means relevant to achieving or having fun. Findings indicated that achievement priming (vs. control priming) activated a goal to achieve and inhibited a goal to have fun in individuals with chronically high-achievement motivation but activated a goal to have fun and inhibited a goal to achieve in individuals with chronically low-achievement motivation.

The Effects of Chronic Achievement Motivation and Achievement Primes on the Activation of Achievement and Fun Goals

PubMed Central

Hart, William; Albarracín, Dolores

2013-01-01

This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit of means relevant to achieving or having fun. Findings indicated that achievement priming (vs. control priming) activated a goal to achieve and inhibited a goal to have fun in individuals with chronically high-achievement motivation but activated a goal to have fun and inhibited a goal to achieve in individuals with chronically low-achievement motivation. PMID:19968423

Molecular perspectives in differentiated thyroid cancer.

PubMed

Buffet, C; Groussin, L

2015-02-01

Progress in understanding the molecular genetics of thyroid cancer in the last 20 years has accelerated recently with the advent of high-throughput sequencing technologies known as Next-Generation Sequencing. Besides classical molecular abnormalities involving the MAPK (Mitogen Activated Protein Kinase) and PI3K (PhosphoInositide 3-Kinase) pathways that play a key role in follicular-derived thyroid tumorigenesis, new molecular abnormalities have been discovered. The major advances in recent years have been the discovery of new somatic driver gene point mutations (such as RASAL1 [RAS protein activator Like 1] mutations in follicular cancer) and/or mutations that have prognostic value (such as TERT [Telomerase reverse transcriptase] promoter mutations); new chromosomal rearrangements, usually having close connection with exposure to ionizing radiation (such as ALK [Anaplastic Lymphoma Kinase] rearrangements); and deregulation of some gene or microRNA expression representing a molecular signature. Progress made in understanding the molecular mechanisms of thyroid cancer offers new perspectives for the diagnosis of the benign or malignant status of a thyroid nodule, to refine prognosis and offer new perspectives of targeted therapy for radioiodine-refractory cancers. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Students’ Achievement Goals, Learning-Related Emotions and Academic Achievement

PubMed Central

Lüftenegger, Marko; Klug, Julia; Harrer, Katharina; Langer, Marie; Spiel, Christiane; Schober, Barbara

2016-01-01

In the present research, the recently proposed 3 × 2 model of achievement goals is tested and associations with achievement emotions and their joint influence on academic achievement are investigated. The study was conducted with 388 students using the 3 × 2 Achievement Goal Questionnaire including the six proposed goal constructs (task-approach, task-avoidance, self-approach, self-avoidance, other-approach, other-avoidance) and the enjoyment and boredom scales from the Achievement Emotion Questionnaire. Exam grades were used as an indicator of academic achievement. Findings from CFAs provided strong support for the proposed structure of the 3 × 2 achievement goal model. Self-based goals, other-based goals and task-approach goals predicted enjoyment. Task-approach goals negatively predicted boredom. Task-approach and other-approach predicted achievement. The indirect effects of achievement goals through emotion variables on achievement were assessed using bias-corrected bootstrapping. No mediation effects were found. Implications for educational practice are discussed. PMID:27199836

Exploring the inter-molecular interactions in amyloid-β protofibril with molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area free energy calculations.

PubMed

Liu, Fu-Feng; Liu, Zhen; Bai, Shu; Dong, Xiao-Yan; Sun, Yan

2012-04-14

Aggregation of amyloid-β (Aβ) peptides correlates with the pathology of Alzheimer's disease. However, the inter-molecular interactions between Aβ protofibril remain elusive. Herein, molecular mechanics Poisson-Boltzmann surface area analysis based on all-atom molecular dynamics simulations was performed to study the inter-molecular interactions in Aβ(17-42) protofibril. It is found that the nonpolar interactions are the important forces to stabilize the Aβ(17-42) protofibril, while electrostatic interactions play a minor role. Through free energy decomposition, 18 residues of the Aβ(17-42) are identified to provide interaction energy lower than -2.5 kcal/mol. The nonpolar interactions are mainly provided by the main chain of the peptide and the side chains of nine hydrophobic residues (Leu17, Phe19, Phe20, Leu32, Leu34, Met35, Val36, Val40, and Ile41). However, the electrostatic interactions are mainly supplied by the main chains of six hydrophobic residues (Phe19, Phe20, Val24, Met35, Val36, and Val40) and the side chains of the charged residues (Glu22, Asp23, and Lys28). In the electrostatic interactions, the overwhelming majority of hydrogen bonds involve the main chains of Aβ as well as the guanidinium group of the charged side chain of Lys28. The work has thus elucidated the molecular mechanism of the inter-molecular interactions between Aβ monomers in Aβ(17-42) protofibril, and the findings are considered critical for exploring effective agents for the inhibition of Aβ aggregation.

Exploring the inter-molecular interactions in amyloid-β protofibril with molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area free energy calculations

NASA Astrophysics Data System (ADS)

Liu, Fu-Feng; Liu, Zhen; Bai, Shu; Dong, Xiao-Yan; Sun, Yan

2012-04-01

Aggregation of amyloid-β (Aβ) peptides correlates with the pathology of Alzheimer's disease. However, the inter-molecular interactions between Aβ protofibril remain elusive. Herein, molecular mechanics Poisson-Boltzmann surface area analysis based on all-atom molecular dynamics simulations was performed to study the inter-molecular interactions in Aβ17-42 protofibril. It is found that the nonpolar interactions are the important forces to stabilize the Aβ17-42 protofibril, while electrostatic interactions play a minor role. Through free energy decomposition, 18 residues of the Aβ17-42 are identified to provide interaction energy lower than -2.5 kcal/mol. The nonpolar interactions are mainly provided by the main chain of the peptide and the side chains of nine hydrophobic residues (Leu17, Phe19, Phe20, Leu32, Leu34, Met35, Val36, Val40, and Ile41). However, the electrostatic interactions are mainly supplied by the main chains of six hydrophobic residues (Phe19, Phe20, Val24, Met35, Val36, and Val40) and the side chains of the charged residues (Glu22, Asp23, and Lys28). In the electrostatic interactions, the overwhelming majority of hydrogen bonds involve the main chains of Aβ as well as the guanidinium group of the charged side chain of Lys28. The work has thus elucidated the molecular mechanism of the inter-molecular interactions between Aβ monomers in Aβ17-42 protofibril, and the findings are considered critical for exploring effective agents for the inhibition of Aβ aggregation.

Symbol interval optimization for molecular communication with drift.

PubMed

Kim, Na-Rae; Eckford, Andrew W; Chae, Chan-Byoung

2014-09-01

In this paper, we propose a symbol interval optimization algorithm in molecular communication with drift. Proper symbol intervals are important in practical communication systems since information needs to be sent as fast as possible with low error rates. There is a trade-off, however, between symbol intervals and inter-symbol interference (ISI) from Brownian motion. Thus, we find proper symbol interval values considering the ISI inside two kinds of blood vessels, and also suggest no ISI system for strong drift models. Finally, an isomer-based molecule shift keying (IMoSK) is applied to calculate achievable data transmission rates (achievable rates, hereafter). Normalized achievable rates are also obtained and compared in one-symbol ISI and no ISI systems.

UCSC genome browser: deep support for molecular biomedical research.

PubMed

Mangan, Mary E; Williams, Jennifer M; Lathe, Scott M; Karolchik, Donna; Lathe, Warren C

2008-01-01

The volume and complexity of genomic sequence data, and the additional experimental data required for annotation of the genomic context, pose a major challenge for display and access for biomedical researchers. Genome browsers organize this data and make it available in various ways to extract useful information to advance research projects. The UCSC Genome Browser is one of these resources. The official sequence data for a given species forms the framework to display many other types of data such as expression, variation, cross-species comparisons, and more. Visual representations of the data are available for exploration. Data can be queried with sequences. Complex database queries are also easily achieved with the Table Browser interface. Associated tools permit additional query types or access to additional data sources such as images of in situ localizations. Support for solving researcher's issues is provided with active discussion mailing lists and by providing updated training materials. The UCSC Genome Browser provides a source of deep support for a wide range of biomedical molecular research (http://genome.ucsc.edu).

Human T-cell lymphotropic virus type 1 subtype C molecular variants among indigenous australians: new insights into the molecular epidemiology of HTLV-1 in Australo-Melanesia.

PubMed

Cassar, Olivier; Einsiedel, Lloyd; Afonso, Philippe V; Gessain, Antoine

2013-01-01

HTLV-1 infection is endemic among people of Melanesian descent in Papua New Guinea, the Solomon Islands and Vanuatu. Molecular studies reveal that these Melanesian strains belong to the highly divergent HTLV-1c subtype. In Australia, HTLV-1 is also endemic among the Indigenous people of central Australia; however, the molecular epidemiology of HTLV-1 infection in this population remains poorly documented. Studying a series of 23 HTLV-1 strains from Indigenous residents of central Australia, we analyzed coding (gag, pol, env, tax) and non-coding (LTR) genomic proviral regions. Four complete HTLV-1 proviral sequences were also characterized. Phylogenetic analyses implemented with both Neighbor-Joining and Maximum Likelihood methods revealed that all proviral strains belong to the HTLV-1c subtype with a high genetic diversity, which varied with the geographic origin of the infected individuals. Two distinct Australians clades were found, the first including strains derived from most patients whose origins are in the North, and the second comprising a majority of those from the South of central Australia. Time divergence estimation suggests that the speciation of these two Australian clades probably occurred 9,120 years ago (38,000-4,500). The HTLV-1c subtype is endemic to central Australia where the Indigenous population is infected with diverse subtype c variants. At least two Australian clades exist, which cluster according to the geographic origin of the human hosts. These molecular variants are probably of very ancient origin. Further studies could provide new insights into the evolution and modes of dissemination of these retrovirus variants and the associated ancient migration events through which early human settlement of Australia and Melanesia was achieved.

Physical health indicators in major mental illness: data from the Quality and Outcome Framework in the UK.

PubMed

Martin, Julie Langan; Lowrie, Richard; McConnachie, Alex; McLean, Gary; Mair, Frances; Mercer, Stewart; Smith, Daniel

2015-02-26

In the UK, the Quality and Outcome Framework (QOF) has specific targets for general practictioners to record body-mass index (BMI) and blood pressure (BP) in major mental illness, diabetes, and chronic kidney disease. Although incentives are given for aspects of major mental illness (schizophrenia, bipolar disorder, and related psychoses), barriers to care can occur. Our aim was to compare recording of specific targets for BP and BMI in individuals with major mental illness relative to diabetes and chronic kidney disease across the UK. Using 2012 and 2013 QOF data from 9731 general practices across all four countries in the UK, we calculated median payment, population achievement, and exception rates for BP indicators in major mental illness and chronic kidney disease and BMI indicators in major mental illness and diabetes. Differences in unweighted rates between practices in the same UK country were tested with a sign test. Differences in population achievement rate between practices in different countries were compared with those in England by use of a quantile regression analysis. UK payment and population achievement rates for BMI recording in major mental illness were significantly lower than were those in diabetes (payment 92·7% vs 95·5% and population achievement 84·0% vs 92·5%, p<0·0001) and exception rates were higher (8·1% vs 2·0%, p<0·0001). For BP recording, UK payment and population achievement rates were significantly lower for major mental illness than for chronic kidney disease (94·1% vs 97·8% and 87·0% vs 97·1%, p<0·0001), whereas exception rate was higher (6·5% vs 0·0%, p<0·0001). This difference was observed for all UK countries. Median population achievement rates for BMI and BP recording in major mental illness were significantly lower in Scotland than in England (for BMI -1·5%, 99% CI -2·7 to -0·3, and for BP -1·8%, -2·7 to -0·9; p<0·0001 for both). There were no cross-jurisdiction differences for chronic kidney disease

Manipulation of individual hyperfine states in cold trapped molecular ions and application to HD+ frequency metrology.

PubMed

Bressel, U; Borodin, A; Shen, J; Hansen, M; Ernsting, I; Schiller, S

2012-05-04

Advanced techniques for manipulation of internal states, standard in atomic physics, are demonstrated for a charged molecular species for the first time. We address individual hyperfine states of rovibrational levels of a diatomic ion by optical excitation of individual hyperfine transitions, and achieve controlled transfer of population into a selected hyperfine state. We use molecular hydrogen ions (HD+) as a model system and employ a novel frequency-comb-based, continuous-wave 5  μm laser spectrometer. The achieved spectral resolution is the highest obtained so far in the optical domain on a molecular ion species. As a consequence, we are also able to perform the most precise test yet of the ab initio theory of a molecule.

Individual Biomarkers Using Molecular Personalized Medicine Approaches.

PubMed

Zenner, Hans P

2017-01-01

Molecular personalized medicine tries to generate individual predictive biomarkers to assist doctors in their decision making. These are thought to improve the efficacy and lower the toxicity of a treatment. The molecular basis of the desired high-precision prediction is modern "omex" technologies providing high-throughput bioanalytical methods. These include genomics and epigenomics, transcriptomics, proteomics, metabolomics, microbiomics, imaging, and functional analyses. In most cases, producing big data also requires a complex biomathematical analysis. Using molecular personalized medicine, the conventional physician's check of biomarker results may no longer be sufficient. By contrast, the physician may need to cooperate with the biomathematician to achieve the desired prediction on the basis of the analysis of individual big data typically produced by omex technologies. Identification of individual biomarkers using molecular personalized medicine approaches is thought to allow a decision-making for the precise use of a targeted therapy, selecting the successful therapeutic tool from a panel of preexisting drugs or medical products. This should avoid the treatment of nonresponders and responders that produces intolerable unwanted effects. © 2017 S. Karger AG, Basel.

Molecular diagnostics for hereditary hearing loss in children.

PubMed

Sommen, Manou; Wuyts, Wim; Van Camp, Guy

2017-08-01

Hearing loss (HL) is the most common birth defect in industrialized countries with far-reaching social, psychological and cognitive implications. It is an extremely heterogeneous disease, complicating molecular testing. The introduction of next-generation sequencing (NGS) has resulted in great progress in diagnostics allowing to study all known HL genes in a single assay. The diagnostic yield is currently still limited, but has the potential to increase substantially. Areas covered: In this review the utility of NGS and the problems for comprehensive molecular testing for HL are evaluated and discussed. Expert commentary: Different publications have proven the appropriateness of NGS for molecular testing of heterogeneous diseases such as HL. However, several problems still exist, such as pseudogenic background of some genes and problematic copy number variant analysis on targeted NGS data. Another main challenge for the future will be the establishment of population specific mutation-spectra to achieve accurate personalized comprehensive molecular testing for HL.

Inputs and Student Achievement: An Analysis of Latina/o-Serving Urban Elementary Schools

ERIC Educational Resources Information Center

Heilig, Julian Vasquez; Williams, Amy; Jez, Su Jin

2010-01-01

One of the most pressing problems in the United States is improving student academic performance, especially the nation's burgeoning Latina/o student population. There is a dearth of research on variables associated with student achievement in Latina/o majority schools in urban districts. As the majority of Latina/o students are segregated into…

Examination of Achievement Gaps among Fourth Grade Students in a Selected Louisiana School District

ERIC Educational Resources Information Center

LeJeune, Kevin Scott

2010-01-01

A major concern for educators is that student achievement is disproportionate and not increasing for all groups at the same rate. This applied dissertation addressed the problem of unequal achievement for African American, economically disadvantaged, and academically at-risk students. This quantitative study utilized a correlational design to…

Low defect densities in molecular beam epitaxial GaAs achieved by isoelectronic In doping

NASA Technical Reports Server (NTRS)

Bhattacharya, P. K.; Dhar, S.; Berger, P.; Juang, F.-Y.

1986-01-01

A study has been made of the effects of adding small amounts of In (0.2-1.2 pct) to GaAs grown by molecular beam epitaxy. The density of four electron traps decreases in concentration by an order of magnitude, and the peak intensities of prominent emissions in the excitonic spectra are reduced with increase in In content. Based on the higher surface migration rate of In, compared to Ga, at the growth temperatures it is apparent that the traps and the excitonic transitions are related to point defects. This agrees with earlier observations by Briones and Collins (1982) and Skromme et al. (1985).

Essential Concepts and Underlying Theories from Physics, Chemistry, and Mathematics for "Biochemistry and Molecular Biology" Majors

ERIC Educational Resources Information Center

Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A.; Bell, Ellis

2013-01-01

Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry,…

Photonic activation of disulfide bridges achieves oriented protein immobilization on biosensor surfaces.

PubMed

Neves-Petersen, Maria Teresa; Snabe, Torben; Klitgaard, Søren; Duroux, Meg; Petersen, Steffen B

2006-02-01

Photonic induced immobilization is a novel technology that results in spatially oriented and spatially localized covalent coupling of biomolecules onto thiol-reactive surfaces. Immobilization using this technology has been achieved for a wide selection of proteins, such as hydrolytic enzymes (lipases/esterases, lysozyme), proteases (human plasminogen), alkaline phosphatase, immunoglobulins' Fab fragment (e.g., antibody against PSA [prostate specific antigen]), Major Histocompability Complex class I protein, pepsin, and trypsin. The reaction mechanism behind the reported new technology involves "photonic activation of disulfide bridges," i.e., light-induced breakage of disulfide bridges in proteins upon UV illumination of nearby aromatic amino acids, resulting in the formation of free, reactive thiol groups that will form covalent bonds with thiol-reactive surfaces (see Fig. 1). Interestingly, the spatial proximity of aromatic residues and disulfide bridges in proteins has been preserved throughout molecular evolution. The new photonic-induced method for immobilization of proteins preserves the native structural and functional properties of the immobilized protein, avoiding the use of one or more chemical/thermal steps. This technology allows for the creation of spatially oriented as well as spatially defined multiprotein/DNA high-density sensor arrays with spot size of 1 microm or less, and has clear potential for biomedical, bioelectronic, nanotechnology, and therapeutic applications.

Study of iron structure stability in high temperature molten lead-bismuth eutectic with oxygen injection using molecular dynamics simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arkundato, Artoto; Su'ud, Zaki; Sudarko

2014-09-30

Corrosion of structural materials in high temperature molten lead-bismuth eutectic is a major problem for design of PbBi cooled reactor. One technique to inhibit corrosion process is to inject oxygen into coolant. In this paper we study and focus on a way of inhibiting the corrosion of iron using molecular dynamics method. For the simulation results we concluded that effective corrosion inhibition of iron may be achieved by injection 0.0532 wt% to 0.1156 wt% oxygen into liquid lead-bismuth. At this oxygen concentration the structure of iron material will be maintained at about 70% in bcc crystal structure during interaction withmore » liquid metal.« less

Molecular testing practices and perceptions among dermatopathologists.

PubMed

Torre, Kristin; Jhorar, Preeti; Wu, Rong; Pfeifer, John; Elaba, Zendee; Murphy, Michael

2018-06-01

We evaluated how dermatopathologists are employing molecular testing in the setting of neoplastic skin diseases, and assessed their opinions of the broader role and utility of molecular technologies in clinical practice. A 15-question online survey was sent to Fellows of the American Society of Dermatopathology in April 2017. One hundred and thirty-six dermatopathologists completed the survey (response rate = 16%). A majority (94%) of respondents reported experience with one or more molecular testing strategies. Sixty-two percent of dermatopathologists order 12 or more molecular tests per year, while 5% of respondents order 2 or fewer assays per year. More frequent utilization of molecular testing is associated with relevant instruction during residency training (P = .009), primary board certification in pathology (P = .008), academic medical center affiliation (P = <.0001), higher volume clinical practice (P = .0004), presence of on-site clinical molecular pathology/cytogenetics laboratory (P = .007), and greater physician confidence incorporating test results into histopathological assessments (P = <.0001). Wider adoption of molecular testing in dermatopathology may be limited by factors such as physician training, test costs/insurance coverage, logistical issues and lack of evidence-based clinical practice guidelines. Dermatopathologists have concerns regarding clinical validity/utility and inappropriate/overuse of some molecular tests. The importance of longitudinal education in molecular technologies and their applications for trainee and practicing physicians is highlighted. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Energy conserving, linear scaling Born-Oppenheimer molecular dynamics.

PubMed

Cawkwell, M J; Niklasson, Anders M N

2012-10-07

Born-Oppenheimer molecular dynamics simulations with long-term conservation of the total energy and a computational cost that scales linearly with system size have been obtained simultaneously. Linear scaling with a low pre-factor is achieved using density matrix purification with sparse matrix algebra and a numerical threshold on matrix elements. The extended Lagrangian Born-Oppenheimer molecular dynamics formalism [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] yields microcanonical trajectories with the approximate forces obtained from the linear scaling method that exhibit no systematic drift over hundreds of picoseconds and which are indistinguishable from trajectories computed using exact forces.

Differential Gender Performance on the Major Field Test-Business

ERIC Educational Resources Information Center

Bielinska-Kwapisz, Agnieszka; Brown, F. William

2013-01-01

The Major Field Test in Business (MFT-B), a standardized assessment test of business knowledge among undergraduate business seniors, is widely used to measure student achievement. Many previous studies analyzing scores on the MFT-B report gender differences on the exam even after controlling for student's aptitude, general intellectual ability,…

Combination of molecular, morphological, and interfacial engineering to achieve highly efficient and stable plastic solar cells.

PubMed

Chang, Chih-Yu; Cheng, Yen-Ju; Hung, Shih-Hsiu; Wu, Jhong-Sian; Kao, Wei-Shun; Lee, Chia-Hao; Hsu, Chain-Shu

2012-01-24

A flexible solar device showing exceptional air and mechanical stability is produced by simultaneously optimizing molecular structure, active layer morphology, and interface characteristics. The PFDCTBT-C8-based devices with inverted architecture exhibited excellent power conversion efficiencies of 7.0% and 6.0% on glass and flexible substrates, respectively. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Latest advances in molecular imaging instrumentation.

PubMed

Pichler, Bernd J; Wehrl, Hans F; Judenhofer, Martin S

2008-06-01

This review concentrates on the latest advances in molecular imaging technology, including PET, MRI, and optical imaging. In PET, significant improvements in tumor detection and image resolution have been achieved by introducing new scintillation materials, iterative image reconstruction, and correction methods. These advances enabled the first clinical scanners capable of time-of-flight detection and incorporating point-spread-function reconstruction to compensate for depth-of-interaction effects. In the field of MRI, the most important developments in recent years have mainly been MRI systems with higher field strengths and improved radiofrequency coil technology. Hyperpolarized imaging, functional MRI, and MR spectroscopy provide molecular information in vivo. A special focus of this review article is multimodality imaging and, in particular, the emerging field of combined PET/MRI.

The Achievement Ideology and Whiteness: "Achieving Whiteness" or "Achieving Middle Class?"

ERIC Educational Resources Information Center

Allen, Ricky Lee

Over the past few decades, social reproduction theorists have criticized achievement ideology as a dominant and dominating myth that hides the true nature of class immobility. Social reproductionists' primary criticism of achievement ideology is that it blinds the working class, regardless of race or gender, to the possibilities of collective…

Protein expression profiling identifies molecular targets of quercetin as a major dietary flavonoid in human colon cancer cells.

PubMed

Wenzel, Uwe; Herzog, Angelika; Kuntz, Sabine; Daniel, Hannelore

2004-07-01

A high dietary intake of plant foods is thought to contribute to the prevention of colorectal cancers in humans and flavonoids as part of such a diet are considered to contribute to those protective effects. Quercetin is a major dietary flavonoid consumed with a diet rich in onions, tea, and apples. We used HT-29 human colon cancer cells and investigated the effects of quercetin on proliferation, apoptosis, and differentiation as processes shown to be disregulated during cancer development. To identify the cellular targets of quercetin action, two-dimensional gel electrophoresis was performed and proteins altered in expression level after quercetin exposure of cells were identified by mass spectrometry of peptide fragments generated by tryptic digestion. Quercetin inhibited the proliferation of HT-29 cells with an IC(50)-value of 81.2 +/- 6.6 microM. Cell differentiation based on surface expression of alkaline phosphatase was enhanced 4-fold and the activity of the pro-apoptotic effector caspase-3 increased 3-fold. Those effects were associated with the regulation of heat-shock proteins and annexins shown to both play a crucial role in the process of apoptosis. Cytoskeletal caspase substrates were found as regulated as well and various proteins involved in intermediary metabolism and in gene regulation showed altered steady-state expression levels upon quercetin treatment of cells. In conclusion, quercetin alters the levels of a variety of proteins involved in growth, differentiation, and apoptosis of colon cancer cells. Their identification as molecular targets of quercetin may explain the anti-cancer activities of this flavonoid.

Genetic link between family socioeconomic status and children's educational achievement estimated from genome-wide SNPs.

PubMed

Krapohl, E; Plomin, R

2016-03-01

One of the best predictors of children's educational achievement is their family's socioeconomic status (SES), but the degree to which this association is genetically mediated remains unclear. For 3000 UK-representative unrelated children we found that genome-wide single-nucleotide polymorphisms could explain a third of the variance of scores on an age-16 UK national examination of educational achievement and half of the correlation between their scores and family SES. Moreover, genome-wide polygenic scores based on a previously published genome-wide association meta-analysis of total number of years in education accounted for ~3.0% variance in educational achievement and ~2.5% in family SES. This study provides the first molecular evidence for substantial genetic influence on differences in children's educational achievement and its association with family SES.

Genetic link between family socioeconomic status and children's educational achievement estimated from genome-wide SNPs

PubMed Central

Krapohl, E; Plomin, R

2016-01-01

One of the best predictors of children's educational achievement is their family's socioeconomic status (SES), but the degree to which this association is genetically mediated remains unclear. For 3000 UK-representative unrelated children we found that genome-wide single-nucleotide polymorphisms could explain a third of the variance of scores on an age-16 UK national examination of educational achievement and half of the correlation between their scores and family SES. Moreover, genome-wide polygenic scores based on a previously published genome-wide association meta-analysis of total number of years in education accounted for ~3.0% variance in educational achievement and ~2.5% in family SES. This study provides the first molecular evidence for substantial genetic influence on differences in children's educational achievement and its association with family SES. PMID:25754083

Molecular musings in microbial ecology and evolution

PubMed Central

2011-01-01

A few major discoveries have influenced how ecologists and evolutionists study microbes. Here, in the format of an interview, we answer questions that directly relate to how these discoveries are perceived in these two branches of microbiology, and how they have impacted on both scientific thinking and methodology. The first question is "What has been the influence of the 'Universal Tree of Life' based on molecular markers?" For evolutionists, the tree was a tool to understand the past of known (cultured) organisms, mapping the invention of various physiologies on the evolutionary history of microbes. For ecologists the tree was a guide to discover the current diversity of unknown (uncultured) organisms, without much knowledge of their physiology. The second question we ask is "What was the impact of discovering frequent lateral gene transfer among microbes?" In evolutionary microbiology, frequent lateral gene transfer (LGT) made a simple description of relationships between organisms impossible, and for microbial ecologists, functions could not be easily linked to specific genotypes. Both fields initially resisted LGT, but methods or topics of inquiry were eventually changed in one to incorporate LGT in its theoretical models (evolution) and in the other to achieve its goals despite that phenomenon (ecology). The third and last question we ask is "What are the implications of the unexpected extent of diversity?" The variation in the extent of diversity between organisms invalidated the universality of species definitions based on molecular criteria, a major obstacle to the adaptation of models developed for the study of macroscopic eukaryotes to evolutionary microbiology. This issue has not overtly affected microbial ecology, as it had already abandoned species in favor of the more flexible operational taxonomic units. This field is nonetheless moving away from traditional methods to measure diversity, as they do not provide enough resolution to uncover what lies

Molecular musings in microbial ecology and evolution.

PubMed

Case, Rebecca J; Boucher, Yan

2011-11-10

A few major discoveries have influenced how ecologists and evolutionists study microbes. Here, in the format of an interview, we answer questions that directly relate to how these discoveries are perceived in these two branches of microbiology, and how they have impacted on both scientific thinking and methodology.The first question is "What has been the influence of the 'Universal Tree of Life' based on molecular markers?" For evolutionists, the tree was a tool to understand the past of known (cultured) organisms, mapping the invention of various physiologies on the evolutionary history of microbes. For ecologists the tree was a guide to discover the current diversity of unknown (uncultured) organisms, without much knowledge of their physiology.The second question we ask is "What was the impact of discovering frequent lateral gene transfer among microbes?" In evolutionary microbiology, frequent lateral gene transfer (LGT) made a simple description of relationships between organisms impossible, and for microbial ecologists, functions could not be easily linked to specific genotypes. Both fields initially resisted LGT, but methods or topics of inquiry were eventually changed in one to incorporate LGT in its theoretical models (evolution) and in the other to achieve its goals despite that phenomenon (ecology).The third and last question we ask is "What are the implications of the unexpected extent of diversity?" The variation in the extent of diversity between organisms invalidated the universality of species definitions based on molecular criteria, a major obstacle to the adaptation of models developed for the study of macroscopic eukaryotes to evolutionary microbiology. This issue has not overtly affected microbial ecology, as it had already abandoned species in favor of the more flexible operational taxonomic units. This field is nonetheless moving away from traditional methods to measure diversity, as they do not provide enough resolution to uncover what lies

Early Childhood Education in Europe. Achievements: Challenges and Possibilities

ERIC Educational Resources Information Center

Urban, Mathias

2009-01-01

This document is the report of a study commissioned by Education International. The aim of this study is to present key characteristics of ECE systems, to highlight strengths and successful approaches and to identify major challenges and areas where urgent action is needed. To achieve this aim, the report comprises two main sections. The first…

Beyond Standard Molecular Dynamics: Investigating the Molecular Mechanisms of G Protein-Coupled Receptors with Enhanced Molecular Dynamics Methods

PubMed Central

Johnston, Jennifer M.

2014-01-01

The majority of biological processes mediated by G Protein-Coupled Receptors (GPCRs) take place on timescales that are not conveniently accessible to standard molecular dynamics (MD) approaches, notwithstanding the current availability of specialized parallel computer architectures, and efficient simulation algorithms. Enhanced MD-based methods have started to assume an important role in the study of the rugged energy landscape of GPCRs by providing mechanistic details of complex receptor processes such as ligand recognition, activation, and oligomerization. We provide here an overview of these methods in their most recent application to the field. PMID:24158803

Molecular robots with sensors and intelligence.

PubMed

Hagiya, Masami; Konagaya, Akihiko; Kobayashi, Satoshi; Saito, Hirohide; Murata, Satoshi

2014-06-17

CONSPECTUS: What we can call a molecular robot is a set of molecular devices such as sensors, logic gates, and actuators integrated into a consistent system. The molecular robot is supposed to react autonomously to its environment by receiving molecular signals and making decisions by molecular computation. Building such a system has long been a dream of scientists; however, despite extensive efforts, systems having all three functions (sensing, computation, and actuation) have not been realized yet. This Account introduces an ongoing research project that focuses on the development of molecular robotics funded by MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan). This 5 year project started in July 2012 and is titled "Development of Molecular Robots Equipped with Sensors and Intelligence". The major issues in the field of molecular robotics all correspond to a feedback (i.e., plan-do-see) cycle of a robotic system. More specifically, these issues are (1) developing molecular sensors capable of handling a wide array of signals, (2) developing amplification methods of signals to drive molecular computing devices, (3) accelerating molecular computing, (4) developing actuators that are controllable by molecular computers, and (5) providing bodies of molecular robots encapsulating the above molecular devices, which implement the conformational changes and locomotion of the robots. In this Account, the latest contributions to the project are reported. There are four research teams in the project that specialize on sensing, intelligence, amoeba-like actuation, and slime-like actuation, respectively. The molecular sensor team is focusing on the development of molecular sensors that can handle a variety of signals. This team is also investigating methods to amplify signals from the molecular sensors. The molecular intelligence team is developing molecular computers and is currently focusing on a new photochemical technology for accelerating DNA

[Establishing Individualized Medicine for Intractable Cancer Based on Clinical Molecular Pathogenesis].

PubMed

Jono, Hirofumi

2018-01-01

　Although cancer treatment has dramatically improved with the development of molecular-targeted agents over the past decade, identifying eligible patients and predicting the therapeutic effects remain a major challenge. Because intratumoral heterogeneity represents genetic and molecular differences affecting patients' responses to these therapeutic agents, establishing individualized medicine based on precise molecular pathological analysis of tumors is urgently required. This review focuses on the pathogenesis of oral squamous cell carcinoma (OSCC), a common head and neck neoplasm, and introduces our approaches toward developing novel anticancer therapies particularly based on clinical molecular pathogenesis. Deeper understanding of more precise molecular pathogenesis in clinical settings may open up novel strategies for establishing individualized medicine for OSCC.

Qualitative Review Synthesis: The Relationship between Inattention and Academic Achievement

ERIC Educational Resources Information Center

Gray, Sarah Anne; Dueck, Katherine; Rogers, Maria; Tannock, Rosemary

2017-01-01

Background: A body of literature has emerged that links inattentive symptoms of attention deficit hyperactivity disorder (ADHD) to poor academic achievement. Major variation across studies renders conclusions about this relationship complex. Purpose: This review will provide a qualitative synthesis of these studies that (1) use community samples…

Achievement as Resistance: The Development of a Critical Race Achievement Ideology among Black Achievers

ERIC Educational Resources Information Center

Carter, Dorinda J.

2008-01-01

In this article, Dorinda Carter examines the embodiment of a critical race achievement ideology in high-achieving black students. She conducted a yearlong qualitative investigation of the adaptive behaviors that nine high-achieving black students developed and employed to navigate the process of schooling at an upper-class, predominantly white,…

B13+ : a photodriven molecular Wankel engine.

PubMed

Zhang, Jin; Sergeeva, Alina P; Sparta, Manuel; Alexandrova, Anastassia N

2012-08-20

Revved-up rotary: A molecular Wankel motor, the dual-ring structure B(13)(+), is driven by circularly-polarized infrared electromagnetic radiation. Calculations show that this illumination leads to a guided unidirectional rotation of the outer ring, which is achieved with rotational frequency of the order of 300 GHz. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Vertex Version of Weighted Wiener Number for Bicyclic Molecular Structures

PubMed Central

Gao, Wei

2015-01-01

Graphs are used to model chemical compounds and drugs. In the graphs, each vertex represents an atom of molecule and edges between the corresponding vertices are used to represent covalent bounds between atoms. We call such a graph, which is derived from a chemical compound, a molecular graph. Evidence shows that the vertex-weighted Wiener number, which is defined over this molecular graph, is strongly correlated to both the melting point and boiling point of the compounds. In this paper, we report the extremal vertex-weighted Wiener number of bicyclic molecular graph in terms of molecular structural analysis and graph transformations. The promising prospects of the application for the chemical and pharmacy engineering are illustrated by theoretical results achieved in this paper. PMID:26640513

Molecular inversion probe assay.

PubMed

Absalan, Farnaz; Ronaghi, Mostafa

2007-01-01

We have described molecular inversion probe technologies for large-scale genetic analyses. This technique provides a comprehensive and powerful tool for the analysis of genetic variation and enables affordable, large-scale studies that will help uncover the genetic basis of complex disease and explain the individual variation in response to therapeutics. Major applications of the molecular inversion probes (MIP) technologies include targeted genotyping from focused regions to whole-genome studies, and allele quantification of genomic rearrangements. The MIP technology (used in the HapMap project) provides an efficient, scalable, and affordable way to score polymorphisms in case/control populations for genetic studies. The MIP technology provides the highest commercially available multiplexing levels and assay conversion rates for targeted genotyping. This enables more informative, genome-wide studies with either the functional (direct detection) approach or the indirect detection approach.

Topology of molecular interaction networks.

PubMed

Winterbach, Wynand; Van Mieghem, Piet; Reinders, Marcel; Wang, Huijuan; de Ridder, Dick

2013-09-16

Molecular interactions are often represented as network models which have become the common language of many areas of biology. Graphs serve as convenient mathematical representations of network models and have themselves become objects of study. Their topology has been intensively researched over the last decade after evidence was found that they share underlying design principles with many other types of networks.Initial studies suggested that molecular interaction network topology is related to biological function and evolution. However, further whole-network analyses did not lead to a unified view on what this relation may look like, with conclusions highly dependent on the type of molecular interactions considered and the metrics used to study them. It is unclear whether global network topology drives function, as suggested by some researchers, or whether it is simply a byproduct of evolution or even an artefact of representing complex molecular interaction networks as graphs.Nevertheless, network biology has progressed significantly over the last years. We review the literature, focusing on two major developments. First, realizing that molecular interaction networks can be naturally decomposed into subsystems (such as modules and pathways), topology is increasingly studied locally rather than globally. Second, there is a move from a descriptive approach to a predictive one: rather than correlating biological network topology to generic properties such as robustness, it is used to predict specific functions or phenotypes.Taken together, this change in focus from globally descriptive to locally predictive points to new avenues of research. In particular, multi-scale approaches are developments promising to drive the study of molecular interaction networks further.

Topology of molecular interaction networks

PubMed Central

2013-01-01

Molecular interactions are often represented as network models which have become the common language of many areas of biology. Graphs serve as convenient mathematical representations of network models and have themselves become objects of study. Their topology has been intensively researched over the last decade after evidence was found that they share underlying design principles with many other types of networks. Initial studies suggested that molecular interaction network topology is related to biological function and evolution. However, further whole-network analyses did not lead to a unified view on what this relation may look like, with conclusions highly dependent on the type of molecular interactions considered and the metrics used to study them. It is unclear whether global network topology drives function, as suggested by some researchers, or whether it is simply a byproduct of evolution or even an artefact of representing complex molecular interaction networks as graphs. Nevertheless, network biology has progressed significantly over the last years. We review the literature, focusing on two major developments. First, realizing that molecular interaction networks can be naturally decomposed into subsystems (such as modules and pathways), topology is increasingly studied locally rather than globally. Second, there is a move from a descriptive approach to a predictive one: rather than correlating biological network topology to generic properties such as robustness, it is used to predict specific functions or phenotypes. Taken together, this change in focus from globally descriptive to locally predictive points to new avenues of research. In particular, multi-scale approaches are developments promising to drive the study of molecular interaction networks further. PMID:24041013

An Insight towards Conceptual Understanding: Looking into the Molecular Structures of Compounds

ERIC Educational Resources Information Center

Uyulgan, Melis Arzu; Akkuzu, Nalan

2016-01-01

The subject of molecular structures is one of the most important and complex subject in chemistry which a majority of the undergraduate students have difficulties to understand its concepts and characteristics correctly. To comprehend the molecular structures and their characteristics the students need to understand related subjects such as Lewis…

Genomic, RNAseq, and Molecular Modeling Evidence Suggests That the Major Allergen Domain in Insects Evolved from a Homodimeric Origin

PubMed Central

Randall, Thomas A.; Perera, Lalith; London, Robert E.; Mueller, Geoffrey A.

2013-01-01

The major allergen domain (MA) is widely distributed in insects. The crystal structure of a single Bla g 1 MA revealed a novel protein fold in which the fundamental structure was a duplex of two subsequences (monomers), which had diverged over time. This suggested that the evolutionary origin of the MA structure may have been a homodimer of this smaller subsequence. Using publicly available genomic data, the distribution of the basic unit of this class of proteins was determined to better understand its evolutionary history. The duplication and divergence is examined at three distinct levels of resolution: 1) within the orders Diptera and Hymenoptera, 2) within one genus Drosophila, and 3) within one species Aedes aegypti. Within the family Culicidae, we have found two separate occurrences of monomers as independent genes. The organization of the gene family in A. aegypti shows a common evolutionary origin for its monomer and several closely related MAs. Molecular modeling of the A. aegypti monomer with the unique Bla g 1 fold confirms the distant evolutionary relationship and supports the feasibility of homodimer formation from a single monomer. RNAseq data for A. aegypti confirms that the monomer is expressed in the mosquito similar to other A. aegypti MAs after a blood meal. Together, these data support the contention that the detected monomer shares similar functional characteristics to related MAs in other insects. An extensive search for this domain outside of Insecta confirms that the MAs are restricted to insects. PMID:24253356

Profiles of Persisting Fourth-Year STEM Majors. ACT Research Report Series 2016 (5)

ERIC Educational Resources Information Center

Westrick, Paul

2016-01-01

Using date from 120,612 students at 26 four-year institutions, this report provides a description of STEM majors entering four-year postsecondary institutions and those who persist through four years of study. The results indicate that persisting STEM majors enter college with very high levels of pre-college academic achievement as measured by the…

Molecular Diversity in Ukrainian Melon Collection as Revealed by AFLP and Microsatellite Markers

USDA-ARS?s Scientific Manuscript database

Thirty-eight melon accessions, which are of primary breeding importance in the Ukraine, were analyzed for diversity. These collections represent a major non-US and non-west Europe source of melon germplasm that have not yet been subjected to molecular characterization. Molecular diversity was esti...

Molecular Imaging of Inflammation in Atherosclerosis

PubMed Central

Wildgruber, Moritz; Swirski, Filip K.; Zernecke, Alma

2013-01-01

Acute rupture of vulnerable plaques frequently leads to myocardial infarction and stroke. Within the last decades, several cellular and molecular players have been identified that promote atherosclerotic lesion formation, maturation and plaque rupture. It is now widely recognized that inflammation of the vessel wall and distinct leukocyte subsets are involved throughout all phases of atherosclerotic lesion development. The mechanisms that render a stable plaque unstable and prone to rupture, however, remain unknown and the identification of the vulnerable plaque remains a major challenge in cardiovascular medicine. Imaging technologies used in the clinic offer minimal information about the underlying biology and potential risk for rupture. New imaging technologies are therefore being developed, and in the preclinical setting have enabled new and dynamic insights into the vessel wall for a better understanding of this complex disease. Molecular imaging has the potential to track biological processes, such as the activity of cellular and molecular biomarkers in vivo and over time. Similarly, novel imaging technologies specifically detect effects of therapies that aim to stabilize vulnerable plaques and silence vascular inflammation. Here we will review the potential of established and new molecular imaging technologies in the setting of atherosclerosis, and discuss the cumbersome steps required for translating molecular imaging approaches into the clinic. PMID:24312156

Elucidating the mechanism of protein water channels by molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Grubmuller, Helmut

2004-03-01

Aquaporins are highly selective water channels. Molecular dynamics simulations of multiple water permeation events correctly predict the measured rate and explain at the atomic level why these membrane channels are so efficient, while blocking other small molecules, ions, and even protons. High efficiency is achieved through a carefully tailored balance of hydrogen bonds that the protein substitutes for the bulk interactions; selectivity is achieved mainly by electrostatic barriers.

Molecular Modeling of Water Interfaces: From Molecular Spectroscopy to Thermodynamics.

PubMed

Nagata, Yuki; Ohto, Tatsuhiko; Backus, Ellen H G; Bonn, Mischa

2016-04-28

Understanding aqueous interfaces at the molecular level is not only fundamentally important, but also highly relevant for a variety of disciplines. For instance, electrode-water interfaces are relevant for electrochemistry, as are mineral-water interfaces for geochemistry and air-water interfaces for environmental chemistry; water-lipid interfaces constitute the boundaries of the cell membrane, and are thus relevant for biochemistry. One of the major challenges in these fields is to link macroscopic properties such as interfacial reactivity, solubility, and permeability as well as macroscopic thermodynamic and spectroscopic observables to the structure, structural changes, and dynamics of molecules at these interfaces. Simulations, by themselves, or in conjunction with appropriate experiments, can provide such molecular-level insights into aqueous interfaces. In this contribution, we review the current state-of-the-art of three levels of molecular dynamics (MD) simulation: ab initio, force field, and coarse-grained. We discuss the advantages, the potential, and the limitations of each approach for studying aqueous interfaces, by assessing computations of the sum-frequency generation spectra and surface tension. The comparison of experimental and simulation data provides information on the challenges of future MD simulations, such as improving the force field models and the van der Waals corrections in ab initio MD simulations. Once good agreement between experimental observables and simulation can be established, the simulation can be used to provide insights into the processes at a level of detail that is generally inaccessible to experiments. As an example we discuss the mechanism of the evaporation of water. We finish by presenting an outlook outlining four future challenges for molecular dynamics simulations of aqueous interfacial systems.

Molecular Environmental Science: An Assessment of Research Accomplishments, Available Synchrotron Radiation Facilities, and Needs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, G

2004-02-05

Synchrotron-based techniques are fundamental to research in ''Molecular Environmental Science'' (MES), an emerging field that involves molecular-level studies of chemical and biological processes affecting the speciation, properties, and behavior of contaminants, pollutants, and nutrients in the ecosphere. These techniques enable the study of aqueous solute complexes, poorly crystalline materials, solid-liquid interfaces, mineral-aqueous solution interactions, microbial biofilm-heavy metal interactions, heavy metal-plant interactions, complex material microstructures, and nanomaterials, all of which are important components or processes in the environment. Basic understanding of environmental materials and processes at the molecular scale is essential for risk assessment and management, and reduction of environmental pollutantsmore » at field, landscape, and global scales. One of the main purposes of this report is to illustrate the role of synchrotron radiation (SR)-based studies in environmental science and related fields and their impact on environmental problems of importance to society. A major driving force for MES research is the need to characterize, treat, and/or dispose of vast quantities of contaminated materials, including groundwater, sediments, and soils, and to process wastes, at an estimated cost exceeding 150 billion dollars through 2070. A major component of this problem derives from high-level nuclear waste. Other significant components come from mining and industrial wastes, atmospheric pollutants derived from fossil fuel consumption, agricultural pesticides and fertilizers, and the pollution problems associated with animal waste run-off, all of which have major impacts on human health and welfare. Addressing these problems requires the development of new characterization and processing technologies--efforts that require information on the chemical speciation of heavy metals, radionuclides, and xenobiotic organic compounds and their reactions

Analyzing Educational Testing Service Graduate Major Field Test Results

ERIC Educational Resources Information Center

Thornton, Barry; Arbogast, Gordon

2012-01-01

The Educational Testing Service (ETS) created the Graduate Major Field Test in Business (GMFT-B) for MBA students. This test is administered to all MBA classes at Jacksonville University for the purpose of measuring student academic achievement and growth, as well as to assess educational outcomes. The test is given in the capstone course,…

Empirical solvent-mediated potentials hold for both intra-molecular and inter-molecular inter-residue interactions.

PubMed Central

Keskin, O.; Bahar, I.; Badretdinov, A. Y.; Ptitsyn, O. B.; Jernigan, R. L.

1998-01-01

Whether knowledge-based intra-molecular inter-residue potentials are valid to represent inter-molecular interactions taking place at protein-protein interfaces has been questioned in several studies. Differences in the chain connectivity effect and in residue packing geometry between interfaces and single chain monomers have been pointed out as possible sources of distinct energetics for the two cases. In the present study, the interfacial regions of protein-protein complexes are examined to extract inter-molecular inter-residue potentials, using the same statistical methods as those previously adopted for intra-molecular residue pairs. Two sets of energy parameters are derived, corresponding to solvent-mediation and "average residue" mediation. The former set is shown to be highly correlated (correlation coefficient 0.89) with that previously obtained for inter-residue interactions within single chain monomers, while the latter exhibits a weaker correlation (0.69) with its intra-molecular counterpart. In addition to the close similarity of intra- and inter-molecular solvent-mediated potentials, they are shown to be significantly more residue-specific and thereby discriminative compared to the residue-mediated ones, indicating that solvent-mediation plays a major role in controlling the effective inter-residue interactions, either at interfaces, or within single monomers. Based on this observation, a reduced set of energy parameters comprising 20 one-body and 3 two-body terms is proposed (as opposed to the 20 x 20 tables of inter-residue potentials), which reproduces the conventional 20 x 20 tables with a correlation coefficient of 0.99. PMID:9865952

Nutrition and educational achievement of urban primary schoolchildren in Malaysia.

PubMed

Shariff, Z M; Bond, J T; Johnson, N E

2000-12-01

The relationship between nutrition, health and educational achievement of school-age population in less developed countries has been of interest to many researchers due to the frequent observation that many children did not complete primary school and those who completed, did not do as well as children in the developed countries. Nevertheless, nutritional and health status by itself is not the only variable affecting educational achievement, since biological, psychological, socioeconomic and cultural factors could directly or indirectly affect both nutrition, health status and educational achievement. The mechanism by which health and nutrition influence educational achievement is not well established, but poor health and malnutrition in early childhood may affect cognitive abilities, necessary for learning process and consequently educational achievement. A study was conducted in Kuala Lumpur, Malaysia, to investigate the relationship between nutritional status and educational achievement among primary schoolchildren from low income households (n = 399). A high percentage of them were mild-significantly underweight (52%), stunted (47%) and wasted (36%) and increasingly overweight (6%). In general, more boys than girls were found to experience some form of malnutrition. While weight-for-height did not differ significantly according to family, child and school factors, weight-for-age and height-for-age differed significantly by gender. Also, height-for-age was significantly related to household income. This indicates that stunting may be a consequence of prolonged socioeconomic deprivation. Educational achievement was measured based on test scores for Malay language (ML), English language (EL) and mathematics (MT). While a majority of the schoolchildren obtained optimum scores (>75) for ML and MT, the majority of them had insufficient scores (<50) for EL. Children's total score (TS) for the three subjects was significantly associated with household socioeconomic

Understanding the molecular mechanism of pulse current charging for stable lithium-metal batteries

PubMed Central

Li, Qi; Tan, Shen; Li, Linlin; Lu, Yingying; He, Yi

2017-01-01

High energy and safe electrochemical storage are critical components in multiple emerging fields of technologies. Rechargeable lithium-metal batteries are considered to be promising alternatives for current lithium-ion batteries, leading to as much as a 10-fold improvement in anode storage capacity (from 372 to 3860 mAh g−1). One of the major challenges for commercializing lithium-metal batteries is the reliability and safety issue, which is often associated with uneven lithium electrodeposition (lithium dendrites) during the charging stage of the battery cycling process. We report that stable lithium-metal batteries can be achieved by simply charging cells with square-wave pulse current. We investigated the effects of charging period and frequency as well as the mechanisms that govern this process at the molecular level. Molecular simulations were performed to study the diffusion and the solvation structure of lithium cations (Li+) in bulk electrolyte. The model predicts that loose association between cations and anions can enhance the transport of Li+ and eventually stabilize the lithium electrodeposition. We also performed galvanostatic measurements to evaluate the cycling behavior and cell lifetime under pulsed electric field and found that the cell lifetime can be more than doubled using certain pulse current waveforms. Both experimental and simulation results demonstrate that the effectiveness of pulse current charging on dendrite suppression can be optimized by choosing proper time- and frequency-dependent pulses. This work provides a molecular basis for understanding the mechanisms of pulse current charging to mitigating lithium dendrites and designing pulse current waveforms for stable lithium-metal batteries. PMID:28776039

MOLECULAR ARCHITECTURE OF THE HUMAN SPERM IZUMO1 AND EGG JUNO FERTILIZATION COMPLEX

PubMed Central

Aydin, Halil; Sultana, Azmiri; Li, Sheng; Thavalingam, Annoj; Lee, Jeffrey E.

2017-01-01

Fertilization is an essential biological process in sexual reproduction and comprises a series of molecular interactions between the sperm and egg1,2. The fusion of haploid spermatozoon and oocyte is the culminating event in mammalian fertilization, enabling the creation of a new genetically distinct diploid organism3,4. The merger of two gametes is achieved through a two-step mechanism where the sperm Izumo1 on the equatorial segment of the acrosome-reacted sperm recognizes its receptor Juno, on the egg surface4–6. This is followed by the fusion of two plasma membranes. Izumo1 and Juno proteins are indispensable for fertilization as constitutive knockout of either Izumo1 or Juno result in mice that are healthy but infertile5,6. Despite their central importance in reproductive medicine, the molecular architectures and the details of their functional roles in fertilization are not known. Here, we present the crystal structures of the human Izumo1 and Juno in unbound and bound conformations. The human Izumo1 structure exhibits a distinct boomerang shape and provides the first structural insights into the Izumo family of proteins7. Human Izumo1 forms a high-affinity complex with Juno and undergoes a major conformational change within its N-terminal domain upon binding to the egg-surface receptor. Our results provide new insights into the molecular basis of sperm-egg recognition, cross-species fertilization, and barrier to polyspermy, thus promising benefits for the rational development of novel non-hormonal contraceptives and fertility treatments for humans and other species of mammals. PMID:27309818

Phylogenetic Framework and Molecular Signatures for the Main Clades of the Phylum Actinobacteria

PubMed Central

Gao, Beile

2012-01-01

Summary: The phylum Actinobacteria harbors many important human pathogens and also provides one of the richest sources of natural products, including numerous antibiotics and other compounds of biotechnological interest. Thus, a reliable phylogeny of this large phylum and the means to accurately identify its different constituent groups are of much interest. Detailed phylogenetic and comparative analyses of >150 actinobacterial genomes reported here form the basis for achieving these objectives. In phylogenetic trees based upon 35 conserved proteins, most of the main groups of Actinobacteria as well as a number of their superageneric clades are resolved. We also describe large numbers of molecular markers consisting of conserved signature indels in protein sequences and whole proteins that are specific for either all Actinobacteria or their different clades (viz., orders, families, genera, and subgenera) at various taxonomic levels. These signatures independently support the existence of different phylogenetic clades, and based upon them, it is now possible to delimit the phylum Actinobacteria (excluding Coriobacteriia) and most of its major groups in clear molecular terms. The species distribution patterns of these markers also provide important information regarding the interrelationships among different main orders of Actinobacteria. The identified molecular markers, in addition to enabling the development of a stable and reliable phylogenetic framework for this phylum, also provide novel and powerful means for the identification of different groups of Actinobacteria in diverse environments. Genetic and biochemical studies on these Actinobacteria-specific markers should lead to the discovery of novel biochemical and/or other properties that are unique to different groups of Actinobacteria. PMID:22390973

Near-term nanotechnology: the molecular fabrication of nanostructured materials

NASA Astrophysics Data System (ADS)

Gillett, Stephen L.

1996-09-01

The remarkably short timescales commonly predicted for achieving full molecular nanotechnology (MNT) are not realistic, as an enormous investment must be made up-front for a distant and ill-defined payoff. The reason is that technology, per se, is not an economic driver; economics instead drives technology. Hence, markets that could motivate the ongoing, incremental development of MNT must be sought. Such markets exist: they fundamentally consist of the molecular assembly of nano structured materials such as semipermeable membranes, catalysts, perfect crystalline fibres, and others. Although in theory atomically precise, such materials have no molecular moving parts and thus will be both easier to build and more robust. Some of these applications (e.g. catalysis), moreover, have huge, mature markets. Once a demand is established, further incremental development of primitive molecular assemblers, or `molecular looms', might then justify the analogies with the explosive development of computer hardware over the last few decades. Finally, the fact that many such applications are likely to be rendered obsolete by full MNT is irrelevant to their interim value as technology drivers.

Biosynthesis, structural architecture and biotechnological potential of bacterial tannase: a molecular advancement.

PubMed

Jana, Arijit; Halder, Suman Kumar; Banerjee, Amrita; Paul, Tanmay; Pati, Bikash Ranjan; Mondal, Keshab Chandra; Das Mohapatra, Pradeep Kumar

2014-04-01

Tannin-rich materials are abundantly generated as wastes from several agroindustrial activities. Therefore, tannase is an interesting hydrolase, for bioconversion of tannin-rich materials into value added products by catalyzing the hydrolysis of ester and depside bonds and unlocked a new prospect in different industrial sectors like food, beverages, pharmaceuticals, etc. Microorganisms, particularly bacteria are one of the major sources of tannase. In the last decade, cloning and heterologous expression of novel tannase genes and structural study has gained momentum. In this article, we have emphasized critically on bacterial tannase that have gained worldwide research interest for their diverse properties. The present paper delineate the developments that have taken place in understanding the role of tannase action, microbial sources, various cultivation aspects, downstream processing, salient biochemical properties, structure and active sites, immobilization, efforts in cloning and overexpression and with special emphasis on recent molecular and biotechnological achievements. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Cobalt Supramolecular Triple-Stranded Helicate-based Discrete Molecular Cage

PubMed Central

Mai, Hien Duy; Kang, Philjae; Kim, Jin Kyung; Yoo, Hyojong

2017-01-01

We report a strategy to achieve a discrete cage molecule featuring a high level of structural hierarchy through a multiple-assembly process. A cobalt (Co) supramolecular triple-stranded helicate (Co-TSH)-based discrete molecular cage (1) is successfully synthesized and fully characterized. The solid-state structure of 1 shows that it is composed of six triple-stranded helicates interconnected by four linking cobalt species. This is an unusual example of a highly symmetric cage architecture resulting from the coordination-driven assembly of metallosupramolecular modules. The molecular cage 1 shows much higher CO2 uptake properties and selectivity compared with the separate supramolecular modules (Co-TSH, complex 2) and other molecular platforms. PMID:28262690

Controlling single-molecule junction conductance by molecular interactions

NASA Astrophysics Data System (ADS)

Kitaguchi, Y.; Habuka, S.; Okuyama, H.; Hatta, S.; Aruga, T.; Frederiksen, T.; Paulsson, M.; Ueba, H.

2015-07-01

For the rational design of single-molecular electronic devices, it is essential to understand environmental effects on the electronic properties of a working molecule. Here we investigate the impact of molecular interactions on the single-molecule conductance by accurately positioning individual molecules on the electrode. To achieve reproducible and precise conductivity measurements, we utilize relatively weak π-bonding between a phenoxy molecule and a STM-tip to form and cleave one contact to the molecule. The anchoring to the other electrode is kept stable using a chalcogen atom with strong bonding to a Cu(110) substrate. These non-destructive measurements permit us to investigate the variation in single-molecule conductance under different but controlled environmental conditions. Combined with density functional theory calculations, we clarify the role of the electrostatic field in the environmental effect that influences the molecular level alignment.

Providing a molecular mechanism for P-glycoprotein; why would I bother?

PubMed Central

Callaghan, Richard

2015-01-01

It is almost 40 years since the drug efflux pump P-glycoprotein (permeability glycoprotein or P-gp) was shown to confer multi-drug resistance in cancer cells. This protein has been one of the most extensively investigated transport proteins due to its intriguing mechanism and its affect in oncology. P-gp is known to interact with over 300 compounds and the ability to achieve this has not yet been revealed. Following the binding of substrate and nucleotide, a complex series of conformational changes in the membrane and cytosolic domains translocates substrate across the membrane. Despite over 30 years of biochemical investigation, the availability of structural data and a plethora of chemical tools to modulate its function, the molecular mechanism remains a mystery. In addition, overcoming its activity in resistant cancer cells has not been achieved in the clinic, thereby garnering some degree of pessimism in the field. This review highlights the progress that has been achieved in understanding this complex protein and the value of undertaking molecular studies. PMID:26517914

Grid computing in large pharmaceutical molecular modeling.

PubMed

Claus, Brian L; Johnson, Stephen R

2008-07-01

Most major pharmaceutical companies have employed grid computing to expand their compute resources with the intention of minimizing additional financial expenditure. Historically, one of the issues restricting widespread utilization of the grid resources in molecular modeling is the limited set of suitable applications amenable to coarse-grained parallelization. Recent advances in grid infrastructure technology coupled with advances in application research and redesign will enable fine-grained parallel problems, such as quantum mechanics and molecular dynamics, which were previously inaccessible to the grid environment. This will enable new science as well as increase resource flexibility to load balance and schedule existing workloads.

Using "Pseudomonas Putida xylE" Gene to Teach Molecular Cloning Techniques for Undergraduates

ERIC Educational Resources Information Center

Dong, Xu; Xin, Yi; Ye, Li; Ma, Yufang

2009-01-01

We have developed and implemented a serial experiment in molecular cloning laboratory course for undergraduate students majored in biotechnology. "Pseudomonas putida xylE" gene, encoding catechol 2, 3-dioxygenase, was manipulated to learn molecular biology techniques. The integration of cloning, expression, and enzyme assay gave students…

Antibody reactivity to the major fish allergen parvalbumin is determined by isoforms and impact of thermal processing.

PubMed

Saptarshi, Shruti R; Sharp, Michael F; Kamath, Sandip D; Lopata, Andreas L

2014-04-01

The EF-hand calcium binding protein, parvalbumin, is a major fish allergen. Detection of this allergen is often difficult due to its structural diversity among various fish species. The aim of this study was to evaluate the cross-reactivity of parvalbumin in a comprehensive range of bony and cartilaginous fish, from the Asia-Pacific region, and conduct a molecular analysis of this highly allergenic protein. Using the monoclonal anti-parvalbumin antibody PARV-19, we demonstrated the presence of monomeric and oligomeric parvalbumin in all fish analysed, except for gummy shark a cartilaginous fish. Heat processing of this allergen greatly affected its antibody reactivity. While heating caused a reduction in antibody reactivity to multimeric forms of parvalbumins for most bony fish, a complete loss of reactivity was observed for cartilaginous fish. Molecular analysis demonstrated that parvalbumin cross-reactivity, among fish species, is due to the molecular phylogenetic association of this major fish allergen. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular design for enhancement of ocular penetration.

PubMed

Shirasaki, Yoshihisa

2008-07-01

Over the past two decades, many oral drugs have been designed in consideration of physicochemical properties to attain optimal pharmacokinetic properties. This strategy significantly reduced attrition in drug development owing to inadequate pharmacokinetics during the last decade. On the other hand, most ophthalmic drugs are generated from reformulation of other therapeutic dosage forms. Therefore, the modification of formulations has been used mainly as the approach to improve ocular pharmacokinetics. However, to maximize ocular pharmacokinetic properties, a specific molecular design for ocular drug is preferable. Passive diffusion of drugs across the cornea membranes requires appropriate lipophilicity and aqueous solubility. Improvement of such physicochemical properties has been achieved by structure optimization or prodrug approaches. This review discusses the current knowledge about ophthalmic drugs adapted from systemic drugs and molecular design for ocular drugs. I propose the approaches for molecular design to obtain the optimal ocular penetration into anterior segment based on published studies to date.

Human Immunodeficiency Virus (HIV) Latency: The Major Hurdle in HIV Eradication

PubMed Central

Tyagi, Mudit; Bukrinsky, Michael

2012-01-01

Failure of highly active antiretroviral therapy to eradicate the human immunodeficiency virus (HIV), even in patients who suppress the virus to undetectable levels for many years, underscores the problems associated with fighting this infection. The existence of persistent infection in certain cellular and anatomical reservoirs appears to be the major hurdle in HIV eradication. The development of therapeutic interventions that eliminate or limit the latent viral pools or prevent the reemergence of the viruses from producing cells will therefore be required to enhance the effectiveness of current antiretroviral strategies. To achieve this goal, there is a pressing need to understand HIV latency at the molecular level to design novel and improved therapies to either eradicate HIV or find a functional cure in which patients could maintain a manageable viral pool without AIDS in the absence of antiretroviral therapy. The integrated proviral genome remains transcriptionally silent for a long period in certain subsets of T cells. This ability to infect cells latently helps HIV to establish a persistent infection despite strong humoral and cellular immune responses against the viral proteins. The main purpose of this report is to provide a general overview of the HIV latency. We will describe the hurdles being faced in eradicating latent HIV proviruses. We will also briefly discuss the ongoing strategies aimed toward curing HIV infection. PMID:22692576

Quantitative ultrasound molecular imaging by modeling the binding kinetics of targeted contrast agent

NASA Astrophysics Data System (ADS)

Turco, Simona; Tardy, Isabelle; Frinking, Peter; Wijkstra, Hessel; Mischi, Massimo

2017-03-01

Ultrasound molecular imaging (USMI) is an emerging technique to monitor diseases at the molecular level by the use of novel targeted ultrasound contrast agents (tUCA). These consist of microbubbles functionalized with targeting ligands with high-affinity for molecular markers of specific disease processes, such as cancer-related angiogenesis. Among the molecular markers of angiogenesis, the vascular endothelial growth factor receptor 2 (VEGFR2) is recognized to play a major role. In response, the clinical-grade tUCA BR55 was recently developed, consisting of VEGFR2-targeting microbubbles which can flow through the entire circulation and accumulate where VEGFR2 is over-expressed, thus causing selective enhancement in areas of active angiogenesis. Discrimination between bound and free microbubbles is crucial to assess cancer angiogenesis. Currently, this is done non-quantitatively by looking at the late enhancement, about 10 min after injection, or by calculation of the differential targeted enhancement, requiring the application of a high-pressure ultrasound (US) burst to destroy all the microbubbles in the acoustic field and isolate the signal coming only from bound microbubbles. In this work, we propose a novel method based on mathematical modeling of the binding kinetics during the tUCA first pass, thus reducing the acquisition time and with no need for a destructive US burst. Fitting time-intensity curves measured with USMI by the proposed model enables the assessment of cancer angiogenesis at both the vascular and molecular levels. This is achieved by estimation of quantitative parameters related to the microvascular architecture and microbubble binding. The proposed method was tested in 11 prostate-tumor bearing rats by performing USMI after injection of BR55, and showed good agreement with current USMI methods. The novel information provided by the proposed method, possibly combined with the current non-quantitative methods, may bring deeper insight into

Informational Sources, Self-Efficacy and Achievement: A Temporally Displaced Approach

ERIC Educational Resources Information Center

Phan, Huy Phuong

2012-01-01

Personal self-efficacy is an important theoretical orientation that helps to explain students' learning and academic achievements. One area of research inquiry has involved the four major sources of information and their predictive effects on self-efficacy. As an extension for examination, the purpose of our investigation was to explore the…

Relationships among Selected Practice Behaviours and Achievement in Jazz Improvisation

ERIC Educational Resources Information Center

Watson, Kevin E.

2015-01-01

The purpose of this exploratory study was to examine the practice strategies that collegiate music majors chose to employ in preparing for a jazz improvisation performance, and the relationships among selected practice behaviours and achievement in instrumental jazz improvisation. Participants for the study (N = 62) were enrolled as music majors…

Co-Relates between Anxiety and Academic Achievement in Teacher Trainees

ERIC Educational Resources Information Center

Yadav, Shivani; Sharma, Savita

2013-01-01

Anxiety is one of the major predictors of academic performance. Teacher trainees with anxiety disorder display a passive attitude in their studies such as lack of interest in learning, poor performance in exams, and on lesson plans & assignments. This research observes the relationship between level of anxiety and academic achievement of…

NABIC marker database: A molecular markers information network of agricultural crops.

PubMed

Kim, Chang-Kug; Seol, Young-Joo; Lee, Dong-Jun; Jeong, In-Seon; Yoon, Ung-Han; Lee, Gang-Seob; Hahn, Jang-Ho; Park, Dong-Suk

2013-01-01

In 2013, National Agricultural Biotechnology Information Center (NABIC) reconstructs a molecular marker database for useful genetic resources. The web-based marker database consists of three major functional categories: map viewer, RSN marker and gene annotation. It provides 7250 marker locations, 3301 RSN marker property, 3280 molecular marker annotation information in agricultural plants. The individual molecular marker provides information such as marker name, expressed sequence tag number, gene definition and general marker information. This updated marker-based database provides useful information through a user-friendly web interface that assisted in tracing any new structures of the chromosomes and gene positional functions using specific molecular markers. The database is available for free at http://nabic.rda.go.kr/gere/rice/molecularMarkers/

Schools in Violent Neighborhoods: The Impact on African American Elementary School Students' Academic Achievement

ERIC Educational Resources Information Center

Ingram, Brenda

2013-01-01

The academic achievement gap between African American and Caucasian students continues to be a major concern for policymakers and educators. This gap started to shrink in the 1970s and 1980s with integration, but the 1990s showed the achievement gap was on the rise again. The characteristics of the neighborhoods where children live and attend…

Extensively Reversible Thermal Transformations of a Bistable, Fluorescence-Switchable Molecular Solid: Entry into Functional Molecular Phase-Change Materials.

PubMed

Srujana, P; Radhakrishnan, T P

2015-06-15

Functional phase-change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous-crystalline transformation of materials like Ge-Sb-Te find use in advanced applications such as information storage. Reversible amorphous-crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Insights into the immuno-molecular biology of Angiostrongylus vasorum through transcriptomics--prospects for new interventions.

PubMed

Ansell, Brendan R E; Schnyder, Manuela; Deplazes, Peter; Korhonen, Pasi K; Young, Neil D; Hall, Ross S; Mangiola, Stefano; Boag, Peter R; Hofmann, Andreas; Sternberg, Paul W; Jex, Aaron R; Gasser, Robin B

2013-12-01

Angiostrongylus vasorum is a metastrongyloid nematode of dogs and other canids of major clinical importance in many countries. In order to gain first insights into the molecular biology of this worm, we conducted the first large-scale exploration of its transcriptome, and predicted essential molecules linked to metabolic and biological processes as well as host immune responses. We also predicted and prioritized drug targets and drug candidates. Following Illumina sequencing (RNA-seq), 52.3 million sequence reads representing adult A. vasorum were assembled and annotated. The assembly yielded 20,033 contigs, which encoded proteins with 11,505 homologues in Caenorhabditis elegans, and additional 2252 homologues in various other parasitic helminths for which curated data sets were publicly available. Functional annotation was achieved for 11,752 (58.6%) proteins predicted for A. vasorum, including peptidases (4.5%) and peptidase inhibitors (1.6%), protein kinases (1.7%), G protein-coupled receptors (GPCRs) (1.5%) and phosphatases (1.2%). Contigs encoding excretory/secretory and immuno-modulatory proteins represented some of the most highly transcribed molecules, and encoded enzymes that digest haemoglobin were conserved between A. vasorum and other blood-feeding nematodes. Using an essentiality-based approach, drug targets, including neurotransmitter receptors, an important chemosensory ion channel and cysteine proteinase-3 were predicted in A. vasorum, as were associated small molecular inhibitors/activators. Future transcriptomic analyses of all developmental stages of A. vasorum should facilitate deep explorations of the molecular biology of this important parasitic nematode and support the sequencing of its genome. These advances will provide a foundation for exploring immuno-molecular aspects of angiostrongylosis and have the potential to underpin the discovery of new methods of intervention. © 2013.

Molecular Imaging in the Era of Personalized Medicine

PubMed Central

Jung, Kyung-Ho; Lee, Kyung-Han

2015-01-01

Clinical imaging creates visual representations of the body interior for disease assessment. The role of clinical imaging significantly overlaps with that of pathology, and diagnostic workflows largely depend on both fields. The field of clinical imaging is presently undergoing a radical change through the emergence of a new field called molecular imaging. This new technology, which lies at the intersection between imaging and molecular biology, enables noninvasive visualization of biochemical processes at the molecular level within living bodies. Molecular imaging differs from traditional anatomical imaging in that biomarkers known as imaging probes are used to visualize target molecules-of-interest. This ability opens up exciting new possibilities for applications in oncologic, neurological and cardiovascular diseases. Molecular imaging is expected to make major contributions to personalized medicine by allowing earlier diagnosis and predicting treatment response. The technique is also making a huge impact on pharmaceutical development by optimizing preclinical and clinical tests for new drug candidates. This review will describe the basic principles of molecular imaging and will briefly touch on three examples (from an immense list of new techniques) that may contribute to personalized medicine: receptor imaging, angiogenesis imaging, and apoptosis imaging. PMID:25812652

Molecular imaging in the era of personalized medicine.

PubMed

Jung, Kyung-Ho; Lee, Kyung-Han

2015-01-01

Clinical imaging creates visual representations of the body interior for disease assessment. The role of clinical imaging significantly overlaps with that of pathology, and diagnostic workflows largely depend on both fields. The field of clinical imaging is presently undergoing a radical change through the emergence of a new field called molecular imaging. This new technology, which lies at the intersection between imaging and molecular biology, enables noninvasive visualization of biochemical processes at the molecular level within living bodies. Molecular imaging differs from traditional anatomical imaging in that biomarkers known as imaging probes are used to visualize target molecules-of-interest. This ability opens up exciting new possibilities for applications in oncologic, neurological and cardiovascular diseases. Molecular imaging is expected to make major contributions to personalized medicine by allowing earlier diagnosis and predicting treatment response. The technique is also making a huge impact on pharmaceutical development by optimizing preclinical and clinical tests for new drug candidates. This review will describe the basic principles of molecular imaging and will briefly touch on three examples (from an immense list of new techniques) that may contribute to personalized medicine: receptor imaging, angiogenesis imaging, and apoptosis imaging.

[Molecular Genetics as Best Evidence in Glioma Diagnostics].

PubMed

Masui, Kenta; Komori, Takashi

2016-03-01

The development of a genomic landscape of gliomas has led to the internally consistent, molecularly-based classifiers. However, development of a biologically insightful classification to guide therapy is still ongoing. Further, tumors are heterogeneous, and they change and adapt in response to drugs. The challenge of developing molecular classifiers that provide meaningful ways to stratify patients for therapy remains a major challenge for the field. Therefore, by incorporating molecular markers into the new World Health Organization (WHO) classification of tumors of the central nervous system, the traditional principle of diagnosis based on histologic criteria will be replaced by a multilayered approach combining histologic features and molecular information in an "integrated diagnosis", to define tumor entities as narrowly as possible. We herein review the current status of diagnostic molecular markers for gliomas, focusing on IDH mutation, ATRX mutation, 1p/19q co-deletion, and TERT promoter mutation in adult tumors, as well as BRAF and H3F3A aberrations in pediatric gliomas, the combination of which will be a promising endeavor to render molecular genetics as a best evidence in the glioma diagnositics.

Molecular Imaging and Precision Medicine in Dementia and Movement Disorders.

PubMed

Mallik, Atul K; Drzezga, Alexander; Minoshima, Satoshi

2017-01-01

Precision medicine (PM) has been defined as "prevention and treatment strategies that take individual variability into account." Molecular imaging (MI) is an ideally suited tool for PM approaches to neurodegenerative dementia and movement disorders (MD). Here we review PM approaches and discuss how they may be applied to other associated neurodegenerative dementia and MD. With ongoing major therapeutic research initiatives that include the use of molecular imaging, we look forward to established interventions targeted to specific molecular pathophysiology and expect the potential benefit of MI PM approaches in neurodegenerative dementia and MD will only increase. Copyright © 2016 Elsevier Inc. All rights reserved.

Reprogrammable Assembly of Molecular Motor on Solid Surfaces via Dynamic Bonds.

PubMed

Yu, Li; Sun, Jian; Wang, Qian; Guan, Yan; Zhou, Le; Zhang, Jingxuan; Zhang, Lanying; Yang, Huai

2017-06-01

Controllable assembly of molecular motors on solid surfaces is a fundamental issue for providing them to perform physical tasks. However, it can hardly be achieved by most previous methods due to their inherent limitations. Here, a general strategy is designed for the reprogrammable assembly of molecular motors on solid surfaces based on dynamic bonds. In this method, molecular motors with disulfide bonds can be remotely, reversibly, and precisely attached to solid surfaces with disulfide bonds, regardless of their chemical composition and microstructure. More importantly, it not only allows encoding geometric information referring to a pattern of molecular motors, but also enables erasing and re-encoding of geometric information via hemolytic photocleavage and recombination of disulfide bonds. Thus, solid surfaces can be regarded as "computer hardware", where molecular motors can be reformatted and reprogramed as geometric information. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strategic placement of stereogenic centers in molecular materials for second harmonic generation.

PubMed

Gangopadhyay, P; Rao, D Narayana; Agranat, Israel; Radhakrishnan, T P

2002-01-01

Basic aspects of the nonlinear optical phenomenon of second harmonic generation (SHG) and the assembly of molecular materials for SHG are reviewed. Extensive use of chirality as a convenient tool to generate noncentrosymmetricity in molecular lattices, an essential requirement for the development of quadratic nonlinear optical materials, is noted. An overview of our investigations of chiral diaminodicyanoquinodimethanes is presented, which provides insight into a systematic approach to the effective deployment of chirality to achieve optimal molecular orientations for enhanced solid state SHG. Extension of these ideas to the realization of strong SHG in materials based on helical superstructures is outlined.

Major depressive disorder: new clinical, neurobiological, and treatment perspectives

PubMed Central

Kupfer, David J; Frank, Ellen; Phillips, Mary L

2012-01-01

In this Seminar we discuss developments from the past 5 years in the diagnosis, neurobiology, and treatment of major depressive disorder. For diagnosis, psychiatric and medical comorbidity have been emphasised as important factors in improving the appropriate assessment and management of depression. Advances in neurobiology have also increased, and we aim to indicate genetic, molecular, and neuroimaging studies that are relevant for assessment and treatment selection of this disorder. Further studies of depression-specific psychotherapies, the continued application of antidepressants, the development of new treatment compounds, and the status of new somatic treatments are also discussed. We address two treatment-related issues: suicide risk with selective serotonin reuptake inhibitors, and the safety of antidepressants in pregnancy. Although clear advances have been made, no fully satisfactory treatments for major depression are available. PMID:22189047

Engineering controllable bidirectional molecular motors based on myosin

NASA Astrophysics Data System (ADS)

Chen, Lu; Nakamura, Muneaki; Schindler, Tony D.; Parker, David; Bryant, Zev

2012-04-01

Cytoskeletal motors drive the transport of organelles and molecular cargoes within cells and have potential applications in molecular detection and diagnostic devices. Engineering molecular motors with controllable properties will allow selective perturbation of mechanical processes in living cells and provide optimized device components for tasks such as molecular sorting and directed assembly. Biological motors have previously been modified by introducing activation/deactivation switches that respond to metal ions and other signals. Here, we show that myosin motors can be engineered to reversibly change their direction of motion in response to a calcium signal. Building on previous protein engineering studies and guided by a structural model for the redirected power stroke of myosin VI, we have constructed bidirectional myosins through the rigid recombination of structural modules. The performance of the motors was confirmed using gliding filament assays and single fluorophore tracking. Our strategy, in which external signals trigger changes in the geometry and mechanics of myosin lever arms, should make it possible to achieve spatiotemporal control over a range of motor properties including processivity, stride size and branchpoint turning.

Molecular characterization of 5S ribosomal RNA genes and transcripts in the protozoan parasite Leishmania major.

PubMed

Moreno-Campos, Rodrigo; Florencio-Martínez, Luis E; Nepomuceno-Mejía, Tomás; Rojas-Sánchez, Saúl; Vélez-Ramírez, Daniel E; Padilla-Mejía, Norma E; Figueroa-Angulo, Elisa; Manning-Cela, Rebeca; Martínez-Calvillo, Santiago

2016-12-01

Eukaryotic 5S rRNA, synthesized by RNA polymerase III (Pol III), is an essential component of the large ribosomal subunit. Most organisms contain hundreds of 5S rRNA genes organized into tandem arrays. However, the genome of the protozoan parasite Leishmania major contains only 11 copies of the 5S rRNA gene, which are interspersed and associated with other Pol III-transcribed genes. Here we report that, in general, the number and order of the 5S rRNA genes is conserved between different species of Leishmania. While in most organisms 5S rRNA genes are normally associated with the nucleolus, combined fluorescent in situ hybridization and indirect immunofluorescence experiments showed that 5S rRNA genes are mainly located at the nuclear periphery in L. major. Similarly, the tandemly repeated 5S rRNA genes in Trypanosoma cruzi are dispersed throughout the nucleus. In contrast, 5S rRNA transcripts in L. major were localized within the nucleolus, and scattered throughout the cytoplasm, where mature ribosomes are located. Unlike other rRNA species, stable antisense RNA complementary to 5S rRNA is not detected in L. major.

Molecular Regulation of the Mitosis/Meiosis Decision in Multicellular Organisms

PubMed Central

Kimble, Judith

2011-01-01

A major step in the journey from germline stem cell to differentiated gamete is the decision to leave the mitotic cell cycle and begin progression through the meiotic cell cycle. Over the past decade, molecular regulators of the mitosis/meiosis decision have been discovered in most of the major model multicellular organisms. Historically, the mitosis/meiosis decision has been closely linked with controls of germline self-renewal and the sperm/egg decision, especially in nematodes and mice. Molecular explanations of those linkages clarify our understanding of this fundamental germ cell decision, and unifying themes have begun to emerge. Although the complete circuitry of the decision is not known in any organism, the recent advances promise to impact key issues in human reproduction and agriculture. PMID:21646377

Molecular regulation of the mitosis/meiosis decision in multicellular organisms.

PubMed

Kimble, Judith

2011-08-01

A major step in the journey from germline stem cell to differentiated gamete is the decision to leave the mitotic cell cycle and begin progression through the meiotic cell cycle. Over the past decade, molecular regulators of the mitosis/meiosis decision have been discovered in most of the major model multicellular organisms. Historically, the mitosis/meiosis decision has been closely linked with controls of germline self-renewal and the sperm/egg decision, especially in nematodes and mice. Molecular explanations of those linkages clarify our understanding of this fundamental germ cell decision, and unifying themes have begun to emerge. Although the complete circuitry of the decision is not known in any organism, the recent advances promise to impact key issues in human reproduction and agriculture.

The Role of PS Ability and RC Skill in Predicting Growth Trajectories of Mathematics Achievement

ERIC Educational Resources Information Center

Vista, Alvin

2016-01-01

There are relatively few studies in Australia and South-East Asian region that combine investigating models of math growth trajectories with predictors such as reasoning ability and reading comprehension skills. Math achievement is one of the major components of overall academic achievement and it is important to determine what factors (especially…

A Study of the Differential Achievement among Graduates of the University of Qatar, 1977-81.

ERIC Educational Resources Information Center

Sefein, Naim A.

Achievement of University of Qatar graduates between 1977 and 1981 was studied. For the sample of 766 graduates, information was collected on sex, nationality, major, and year of graduation. The degree to which secondary school graduation scores can predict college achievement was examined using Pearson product moment correlation coefficients. The…

Within the Pipeline: Self-Regulated Learning and Academic Achievement among College Students in Science Courses

ERIC Educational Resources Information Center

DiBenedetto, Maria K.; Bembenutty, Hefer

2011-01-01

The present study examined the associations between self-regulated learning and science achievement and whether the academic self-regulation variables described, such as self-efficacy, delay of gratification, and help seeking, predict science achievement in courses deemed necessary for a major in science. It was hypothesized that students who do…

Benefits of and Barriers to Pharmacogenomics-Guided Treatment for Major Depressive Disorder.

PubMed

Ahmed, Ahmed T; Weinshilboum, Richard; Frye, Mark A

2018-05-01

Antidepressants have reduced the symptom burden for many Major Depressive Disorder (MDD) patients, but drug-related side effects and treatment resistance continue to present major challenges. Pharmacogenomics represents one approach to enhance antidepressant efficacy and avoid adverse reactions, but concerns remain with regard to the overall "value equation," and several barriers must be overcome to achieve the full potential of MDD pharmacogenomics. © 2018 American Society for Clinical Pharmacology and Therapeutics.

Achievement for African-American Students: Strategies for the Diverse Classroom.

ERIC Educational Resources Information Center

Reglin, Gary L.

This book has been designed to provide teachers of kindergarten through grade 12 with techniques and approaches for helping their African American students achieve in school. It presents a planned approach to four major initiatives: (1) to restructure the instruction and behaviors practiced in most classrooms today; (2) to provide teachers with…

The Molecular Biology Capstone Assessment: A Concept Assessment for Upper-Division Molecular Biology Students

PubMed Central

Couch, Brian A.; Wood, William B.; Knight, Jennifer K.

2015-01-01

Measuring students’ conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in novel scenarios. Targeted at graduating students, the MBCA consists of 18 multiple-true/false (T/F) questions. Each question consists of a narrative stem followed by four T/F statements, which allows a more detailed assessment of student understanding than the traditional multiple-choice format. Questions were iteratively developed with extensive faculty and student feedback, including validation through faculty reviews and response validation through student interviews. The final assessment was taken online by 504 students in upper-division courses at seven institutions. Data from this administration indicate that the MBCA has acceptable levels of internal reliability (α = 0.80) and test–retest stability (r = 0.93). Students achieved a wide range of scores with a 67% overall average. Performance results suggest that students have an incomplete understanding of many molecular biology concepts and continue to hold incorrect conceptions previously documented among introductory-level students. By pinpointing areas of conceptual difficulty, the MBCA can provide faculty members with guidance for improving undergraduate biology programs. PMID:25713098

HDAC4 as a potential therapeutic target in neurodegenerative diseases: a summary of recent achievements

PubMed Central

Mielcarek, Michal; Zielonka, Daniel; Carnemolla, Alisia; Marcinkowski, Jerzy T.; Guidez, Fabien

2015-01-01

For the past decade protein acetylation has been shown to be a crucial post-transcriptional modification involved in the regulation of protein functions. Histone acetyltransferases (HATs) mediate acetylation of histones which results in the nucleosomal relaxation associated with gene expression. The reverse reaction, histone deacetylation, is mediated by histone deacetylases (HDACs) leading to chromatin condensation followed by transcriptional repression. HDACs are divided into distinct classes: I, IIa, IIb, III, and IV, on the basis of size and sequence homology, as well as formation of distinct repressor complexes. Implications of HDACs in many diseases, such as cancer, heart failure, and neurodegeneration, have identified these molecules as unique and attractive therapeutic targets. The emergence of HDAC4 among the members of class IIa family as a major player in synaptic plasticity raises important questions about its functions in the brain. The characterization of HDAC4 specific substrates and molecular partners in the brain will not only provide a better understanding of HDAC4 biological functions but also might help to develop new therapeutic strategies to target numerous malignancies. In this review we highlight and summarize recent achievements in understanding the biological role of HDAC4 in neurodegenerative processes. PMID:25759639

The molecular genetics of insecticide resistance.

PubMed

Ffrench-Constant, Richard H

2013-08-01

The past 60 years have seen a revolution in our understanding of the molecular genetics of insecticide resistance. While at first the field was split by arguments about the relative importance of mono- vs. polygenic resistance and field- vs. laboratory-based selection, the application of molecular cloning to insecticide targets and to the metabolic enzymes that degrade insecticides before they reach those targets has brought out an exponential growth in our understanding of the mutations involved. Molecular analysis has confirmed the relative importance of single major genes in target-site resistance and has also revealed some interesting surprises about the multi-gene families, such as cytochrome P450s, involved in metabolic resistance. Identification of the mutations involved in resistance has also led to parallel advances in our understanding of the enzymes and receptors involved, often with implications for the role of these receptors in humans. This Review seeks to provide an historical perspective on the impact of molecular biology on our understanding of resistance and to begin to look forward to the likely impact of rapid advances in both sequencing and genome-wide association analysis.

Next generation extended Lagrangian first principles molecular dynamics

NASA Astrophysics Data System (ADS)

Niklasson, Anders M. N.

2017-08-01

Extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] is formulated for general Hohenberg-Kohn density-functional theory and compared with the extended Lagrangian framework of first principles molecular dynamics by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. It is shown how extended Lagrangian Born-Oppenheimer molecular dynamics overcomes several shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while improving or maintaining important features of Car-Parrinello simulations. The accuracy of the electronic degrees of freedom in extended Lagrangian Born-Oppenheimer molecular dynamics, with respect to the exact Born-Oppenheimer solution, is of second-order in the size of the integration time step and of fourth order in the potential energy surface. Improved stability over recent formulations of extended Lagrangian Born-Oppenheimer molecular dynamics is achieved by generalizing the theory to finite temperature ensembles, using fractional occupation numbers in the calculation of the inner-product kernel of the extended harmonic oscillator that appears as a preconditioner in the electronic equations of motion. Material systems that normally exhibit slow self-consistent field convergence can be simulated using integration time steps of the same order as in direct Born-Oppenheimer molecular dynamics, but without the requirement of an iterative, non-linear electronic ground-state optimization prior to the force evaluations and without a systematic drift in the total energy. In combination with proposed low-rank and on the fly updates of the kernel, this formulation provides an efficient and general framework for quantum-based Born-Oppenheimer molecular dynamics simulations.

Next generation extended Lagrangian first principles molecular dynamics.

PubMed

Niklasson, Anders M N

2017-08-07

Extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] is formulated for general Hohenberg-Kohn density-functional theory and compared with the extended Lagrangian framework of first principles molecular dynamics by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. It is shown how extended Lagrangian Born-Oppenheimer molecular dynamics overcomes several shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while improving or maintaining important features of Car-Parrinello simulations. The accuracy of the electronic degrees of freedom in extended Lagrangian Born-Oppenheimer molecular dynamics, with respect to the exact Born-Oppenheimer solution, is of second-order in the size of the integration time step and of fourth order in the potential energy surface. Improved stability over recent formulations of extended Lagrangian Born-Oppenheimer molecular dynamics is achieved by generalizing the theory to finite temperature ensembles, using fractional occupation numbers in the calculation of the inner-product kernel of the extended harmonic oscillator that appears as a preconditioner in the electronic equations of motion. Material systems that normally exhibit slow self-consistent field convergence can be simulated using integration time steps of the same order as in direct Born-Oppenheimer molecular dynamics, but without the requirement of an iterative, non-linear electronic ground-state optimization prior to the force evaluations and without a systematic drift in the total energy. In combination with proposed low-rank and on the fly updates of the kernel, this formulation provides an efficient and general framework for quantum-based Born-Oppenheimer molecular dynamics simulations.

Surgical management of giant sphenoid wing meningiomas encasing major cerebral arteries.

PubMed

Champagne, Pierre-Olivier; Lemoine, Emile; Bojanowski, Michel W

2018-04-01

OBJECTIVE Sphenoid wing meningiomas are a heterogeneous group of tumors with variable surgical risks and prognosis. Those that have grown to a very large size, encasing the major cerebral arteries, are associated with a high risk of stroke. In reviewing the authors' series of giant sphenoid wing meningiomas, the goal was to evaluate how the extent of the tumor's invasion of surrounding structures affected the ability to safely remove the tumor and restore function. METHODS The authors conducted a retrospective study of a series of giant sphenoid wing meningiomas operated on between 1996 and 2016. Inclusion criteria were meningiomas with a globoid component ≥ 6 cm, encasing at least 1 major intradural cerebral artery. Extent of resection was measured according to Simpson grade. RESULTS This series included 12 patients, with a mean age of 59 years. Visual symptoms were the most common clinical presentation. There was complete or partial encasement of all 3 major cerebral arteries except for 3 cases in which only the anterior cerebral artery was not involved. The lateral wall of the cavernous sinus was invaded in 8 cases (67%) and the optic canal in 6 (50%). Complete resection was achieved in 2 cases (Simpson grades 2 and 3). In the remaining 10 cases of partial resection (Simpson grade 4), radical removal (> 90%) was achieved in 7 cases (70%). In the immediate postoperative period, there were no deaths. Four of 9 patients with visual deficits improved, while the 5 others remained unchanged. Two patients experienced transient neurological deficits. Other than an asymptomatic lacuna of the internal capsule, there were no ischemic lesions following surgery. Tumor recurrence occurred in 5 patients, between 24 and 168 months (mean 61 months) following surgery. CONCLUSIONS Although these giant lesions encasing major cerebral arteries are particularly treacherous for surgery, this series demonstrates that it is possible to safely achieve radical removal and at times even

Turning randomness into meaning at the molecular level using Muller's morphs

PubMed Central

Henson, Kathleen; Cooper, Melanie M.; Klymkowsky, Michael W.

2012-01-01

Summary While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985), historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005). While molecular mechanisms address this issue (Jablonka and Lamb, 2005), analysis of responses to the Biological Concept Inventory (BCI) (Klymkowsky et al., 2010), revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a “Socratic tutorial” focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932). Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms. PMID:23213431

Turning randomness into meaning at the molecular level using Muller's morphs.

PubMed

Henson, Kathleen; Cooper, Melanie M; Klymkowsky, Michael W

2012-04-15

While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985), historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005). While molecular mechanisms address this issue (Jablonka and Lamb, 2005), analysis of responses to the Biological Concept Inventory (BCI) (Klymkowsky et al., 2010), revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a "Socratic tutorial" focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932). Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms.

Molecular chaperone properties of the high molecular weight aggregate from aged lens

NASA Technical Reports Server (NTRS)

Takemoto, L.; Boyle, D.; Spooner, B. S. (Principal Investigator)

1994-01-01

The high molecular weight aggregate (HMWA) fraction was isolated from the water soluble proteins of aged bovine lenses. Its composition and ability to inhibit heat-induced denaturation and aggregation were compared with the lower molecular weight, oligomeric fraction of alpha isolated from the same lens. Although the major components of both fractions were the alpha-A and alpha-B chains, the HMWA fraction possessed a decreased ability to protect other proteins against heat-induced denaturation and aggregation. Immunoelectron microscopy of both fractions demonstrated that alpha particles from the HMWA fraction contained increased amounts of beta and gamma crystallins, bound to a central region of the supramolecular complex. Together, these results demonstrate that alpha crystallins found in the HMWA fraction possess a decreased ability to protect against heat-induced denaturation and aggregation, and suggest that at least part of this decrease could be due to the increased presence of beta and gamma crystallins complexed to the putative chaperone receptor site of the alpha particles.

Escitalopram—translating molecular properties into clinical benefit: reviewing the evidence in major depression

PubMed Central

Leonard, Brian; Taylor, David

2010-01-01

The majority of currently marketed drugs contain a mixture of enantiomers; however, recent evidence suggests that individual enantiomers can have pharmacological properties that differ importantly from enantiomer mixtures. Escitalopram, the S-enantiomer of citalopram, displays markedly different pharmacological activity to the R-enantiomer. This review aims to evaluate whether these differences confer any significant clinical advantage for escitalopram over either citalopram or other frequently used antidepressants. Searches were conducted using PubMed and EMBASE (up to January 2009). Abstracts of the retrieved studies were reviewed independently by both authors for inclusion. Only those studies relating to depression or major depressive disorder were included. The search identified over 250 citations, of which 21 studies and 18 pooled or meta-analyses studies were deemed suitable for inclusion. These studies reveal that escitalopram has some efficacy advantage over citalopram and paroxetine, but no consistent advantage over other selective serotonin reuptake inhibitors. Escitalopram has at least comparable efficacy to available serotonin-norepinephrine reuptake inhibitors, venlafaxine XR and duloxetine, and may offer some tolerability advantages over these agents. This review suggests that the mechanistic advantages of escitalopram over citalopram translate into clinical efficacy advantages. Escitalopram may have a favourable benefit-risk ratio compared with citalopram and possibly with several other antidepressant agents. PMID:20147575

Optima HD Imax: Molecular Implant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tieger, D. R.; Splinter, P. R.; Hsieh, T. J.

2008-11-03

Molecular implantation offers semiconductor device manufacturers multiple advantages over traditional high current ion implanters. The dose multiplication due to implanting more than one atom per molecule and the transport of beams at higher energies relative to the effective particle energies result in significant throughput enhancements without risk of energy contamination. The Optima HD Imax is introduced with molecular implant capability and the ability to reach up to 4.2 keV effective {sup 11}B from octadecaborane (B{sub 18}H{sub 22}). The ion source and beamline are optimized for molecular species ionization and transport. The beamline is coupled to the Optima HD mechanically scannedmore » endstation. The use of spot beam technology with ionized molecules maximizes the throughput potential and produces uniform implants with fast setup time and with superior angle control. The implanter architecture is designed to run multiple molecular species; for example, in addition to B{sub 18}H{sub 22} the system is capable of implanting carbon molecules for strain engineering and shallow junction engineering. Source lifetime data and typical operating conditions are described both for high dose, memory applications such as dual poly gate as well as lower energy implants for source drain extension and contact implants. Throughputs have been achieved in excess of 50 wafers per hour at doses up to 1x10{sup 16} ions/cm{sup 2} and for energies as low as 1 keV.« less

Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

NASA Technical Reports Server (NTRS)

Thronson, Harley A.; Lester, Daniel F.

2008-01-01

Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx.10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover, as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders, if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating

Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

NASA Technical Reports Server (NTRS)

Thronson, Harley; Lester, Daniel F.

2008-01-01

Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx. 10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover. as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders. if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating

Persistence patterns of mathematics and science majors: A profile of highly motivated freshmen

NASA Astrophysics Data System (ADS)

Gonzales, Erin E.

Despite an increasing demand for college graduates skilled in science, technology, engineering, and mathematics ("STEM") fields, a substantial number of students who choose these majors leave after taking their first-year "gateway" math and science coursework. Research has shown GPA to be a salient predictor of persistence in STEM majors: Students who earn high grades in gateway courses are more likely to continue, and those who earn low grades are more likely to leave. However, a small number of students defy that expectation: Despite a low gateway course GPA, they persist not just to the sophomore year but all the way to graduation. The purpose of this study was to determine what other experiences, motivations, or attributes aside from academic performance influence these students to persist. A qualitative approach was taken with the use of semi-structured interviews, which provided a means for analysis based on insights directly from students. An invitation was sent to a cohort of graduating math and science majors at a large public institution, and 10 eligible volunteers were chosen to participate. A thematic analysis was conducted to seek common themes in the students' interviews regarding their experiences in their gateway coursework, their feelings towards their chosen major, their beliefs about their academic proficiency, their motivations for continuing in their major, and other prominent characteristics they attributed to their persistence. Five themes were found: Ambition, dedication, achievement, culture shock, and resilience. Of the five themes, four are attributes of the students themselves: Ambition, dedication, achievement, and resilience. The fifth, culture shock, is something that happened to them, although it does contain information about the students insofar as how they handled the situation. The end result was the identification of a specific group of students: High achievers majoring in math and science who are self-driven and independent, as

Carrier-envelope phase-dependent field-free molecular orientation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu Chuancun; Yuan Kaijun; Hu Wenhui

2009-07-15

We present a strategy to achieve carrier-envelope phase-dependent field-free molecular orientation with the use of carrier-envelope phase (CEP) stabilization and asymmetric few-cycle terahertz (THz) laser pulses. The calculations are performed on the LiH molecule by an exact solution of the full time-dependent Schroedinger equation including both the vibrational and the rotational degrees of freedom. Our calculations show that an efficient field-free molecular orientation can be obtained even at considerable temperatures. Moreover, we find a simple dependence of the field-free orientation on the CEP, which implies that the CEP becomes an important parameter for control of molecular orientation. More importantly, themore » realization of this scenario is appealing based on the fact that the intense few-cycle THz pulse with duration as short as a few optical cycles is available as a research tool.« less

Molecular Cancer Prevention: Current Status & Future Directions

PubMed Central

Maresso, Karen Colbert; Tsai, Kenneth Y.; Brown, Powel H.; Szabo, Eva; Lippman, Scott; Hawk, Ernest

2016-01-01

The heterogeneity and complexity of advanced cancers strongly supports the rationale for an enhanced focus on molecular prevention as a priority strategy to reduce the burden of cancer. Molecular prevention encompasses traditional chemopreventive agents as well as vaccinations and therapeutic approaches to cancer-predisposing conditions. Despite challenges to the field, we now have refined insights into cancer etiology and early pathogenesis; successful risk assessment and new risk models; agents with broad preventive efficacy (e.g., aspirin) in common chronic diseases, including cancer; and a successful track record of more than 10 agents approved by the FDA for the treatment of precancerous lesions or cancer risk reduction. The development of molecular preventive agents does not differ significantly from the development of therapies for advanced cancers, yet has unique challenges and special considerations given that it most often involves healthy or asymptomatic individuals. Agents, biomarkers, cohorts, overall design, and endpoints are key determinants of molecular preventive trials, as with therapeutic trials, although distinctions exist for each within the preventive setting. Progress in the development and evolution of molecular preventive agents has been steadier in some organ systems, such as breast and skin, than in others. In order for molecular prevention to be fully realized as an effective strategy, a number of challenges to the field must be addressed. Here we provide a brief overview of the context for and special considerations of molecular prevention along with a discussion of the results of major randomized controlled trials. PMID:26284997

Cooperative genomic alteration network reveals molecular classification across 12 major cancer types

PubMed Central

Zhang, Hongyi; Deng, Yulan; Zhang, Yong; Ping, Yanyan; Zhao, Hongying; Pang, Lin; Zhang, Xinxin; Wang, Li; Xu, Chaohan; Xiao, Yun; Li, Xia

2017-01-01

The accumulation of somatic genomic alterations that enables cells to gradually acquire growth advantage contributes to tumor development. This has the important implication of the widespread existence of cooperative genomic alterations in the accumulation process. Here, we proposed a computational method HCOC that simultaneously consider genetic context and downstream functional effects on cancer hallmarks to uncover somatic cooperative events in human cancers. Applying our method to 12 TCGA cancer types, we totally identified 1199 cooperative events with high heterogeneity across human cancers, and then constructed a pan-cancer cooperative alteration network. These cooperative events are associated with genomic alterations of some high-confident cancer drivers, and can trigger the dysfunction of hallmark associated pathways in a co-defect way rather than single alterations. We found that these cooperative events can be used to produce a prognostic classification that can provide complementary information with tissue-of-origin. In a further case study of glioblastoma, using 23 cooperative events identified, we stratified patients into molecularly relevant subtypes with a prognostic significance independent of the Glioma-CpG Island Methylator Phenotype (GCIMP). In summary, our method can be effectively used to discover cancer-driving cooperative events that can be valuable clinical markers for patient stratification. PMID:27899621

Membranes. Metal-organic framework nanosheets as building blocks for molecular sieving membranes.

PubMed

Peng, Yuan; Li, Yanshuo; Ban, Yujie; Jin, Hua; Jiao, Wenmei; Liu, Xinlei; Yang, Weishen

2014-12-12

Layered metal-organic frameworks would be a diverse source of crystalline sheets with nanometer thickness for molecular sieving if they could be exfoliated, but there is a challenge in retaining the morphological and structural integrity. We report the preparation of 1-nanometer-thick sheets with large lateral area and high crystallinity from layered MOFs. They are used as building blocks for ultrathin molecular sieve membranes, which achieve hydrogen gas (H2) permeance of up to several thousand gas permeation units (GPUs) with H2/CO2 selectivity greater than 200. We found an unusual proportional relationship between H2 permeance and H2 selectivity for the membranes, and achieved a simultaneous increase in both permeance and selectivity by suppressing lamellar stacking of the nanosheets. Copyright © 2014, American Association for the Advancement of Science.

Is Higher Better? Determinants and Comparisons of Performance on the Major Field Test in Business

ERIC Educational Resources Information Center

Bielinska-Kwapisz, Agnieszka; Brown, F. William; Semenik, Richard

2012-01-01

Student performance on the Major Field Achievement Test in Business is an important benchmark for college of business programs. The authors' results indicate that such benchmarking can only be meaningful if certain student characteristics are taken into account. The differences in achievement between cohorts are explored in detail by separating…

The Longitudinal Link between Student Health and Math Achievement Scores

ERIC Educational Resources Information Center

Garcy, Anthony M.

2009-01-01

This study investigated the relationship between health conditions suffered over time and student scores on the Stanford Achievement Test 9 in Yuma County, Arizona, public grade schools. The majority of children in Yuma County were of Hispanic origin. The poverty and low income status of most of these children placed them at greater risk for…

The Effect of Peer-Based Instruction on Rhythm Reading Achievement

ERIC Educational Resources Information Center

Johnson, Erik A.

2011-01-01

The purpose of this study was to determine the effect of peer-based instruction on rhythm reading achievement of instrumental and choral music students attending a large urbanfringe high school in a major metropolitan area. Participants (N = 131) included band (n = 71) and choir (n = 60) students whose backgrounds reflected extensive economic (78%…

NGC 3503 and its molecular environment

NASA Astrophysics Data System (ADS)

Duronea, N. U.; Vasquez, J.; Cappa, C. E.; Corti, M.; Arnal, E. M.

2012-01-01

Aims: We present a study of the molecular gas and interstellar dust distribution in the environs of the Hii region NGC 3503 associated with the open cluster Pis 17 with the aim of investigating the spatial distribution of the molecular gas linked to the nebula and achieving a better understanding of the interaction of the nebula and Pis 17 with their molecular environment. Methods: We based our study on 12CO(1-0) observations of a region of ~0.6° in size obtained with the 4-m NANTEN telescope, unpublished radio continuum data at 4800 and 8640 MHz obtained with the ATCA telescope, radio continuum data at 843 MHz obtained from SUMSS, and available IRAS, MSX, IRAC-GLIMPSE, and MIPSGAL images. Results: We found a molecular cloud (Component 1) having a mean velocity of -24.7 km s-1 ,compatible with the velocity of the ionized gas, which is associated with the nebula and its surroundings. Adopting a distance of 2.9 ± 0.4 kpc, the total molecular mass yields (7.6 ± 2.1) × 103M⊙ and density yields 400 ± 240 cm-3. The radio continuum data confirm the existence of an electron density gradient in NGC 3503. The IR emission shows a PDR bordering the higher density regions of the nebula. The spatial distribution of the CO emission shows that the nebula coincides with a molecular clump, and the strongest CO emission peak is located close to the higher electron density region. The more negative velocities of the molecular gas (about -27 km s-1), are coincident with NGC 3503. Candidate young stellar objects (YSOs) were detected toward the Hii region, suggesting that embedded star formation may be occurring in the neighborhood of the nebula. The clear electron density gradient, along with the spatial distribution of the molecular gas and PAHs in the region indicates that NGC 3503 is a blister-type Hii region that has probably undergone a champagne phase.

Latest achievements in PET techniques

NASA Astrophysics Data System (ADS)

Del Guerra, Alberto; Belcari, Nicola; Motta, Alfonso; Di Domenico, Giovanni; Sabba, Nicola; Zavattini, Guido

2003-11-01

Positron emission tomography (PET) has moved from a distinguished research tool in physiology, cardiology and neurology to become a major tool for clinical investigation in oncology, in cardiac applications and in neurological disorders. Much of the PET accomplishments is due to the remarkable improvements in the last 10 years both in hardware and software aspects. Nowadays a similar effort is made by many research groups towards the construction of dedicated PET apparatus in new emerging fields such as molecular medicine, gene therapy, breast cancer imaging and combined modalities. This paper reports on some recent results we have obtained in small animal imaging and positron emission mammography, based on the use of advanced technology in the field of scintillators and photodetectors, such as Position-Sensitive Detectors coupled to crystal matrices, combined use of scintillating fibers and Hybrid-Photo-Diodes readout, and Hamamatsu flat panels. New ideas and future developments are discussed.

Dynamic Geometry Software Improves Mathematical Achievement: Systematic Review and Meta-Analysis

ERIC Educational Resources Information Center

Chan, Kan Kan; Leung, Siu Wai

2014-01-01

Dynamic geometry software (DGS) aims to enhance mathematics education. This systematic review and meta-analysis evaluated the quasi-experimental studies on the effectiveness of DGS-based instruction in improving students' mathematical achievement. Research articles published between 1990 and 2013 were identified from major databases according to a…

Effect of Three Instructional Strategies on Students' Attitudes and Cognitive Achievement

ERIC Educational Resources Information Center

Schaffer, Dennis R.; Purohit, Anal

1975-01-01

The purpose of this study was to determine the effects of different instructional strategies upon the attitudes and cognitive achievement of nursing students. The major conclusions were: (a) fewer students were manifesting philosophies supportive of independent study strategies, and (b) significant interaction between students' attitudes,…

Single-molecule analysis of the major glycopolymers of pathogenic and non-pathogenic yeast cells

NASA Astrophysics Data System (ADS)

El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Alsteens, David; Sarazin, Aurore; Jouault, Thierry; Dufrêne, Yves F.

2013-05-01

Most microbes are coated with carbohydrates that show remarkable structural variability and play a crucial role in mediating microbial-host interactions. Understanding the functions of cell wall glycoconjugates requires detailed knowledge of their molecular organization, diversity and heterogeneity. Here we use atomic force microscopy (AFM) with tips bearing specific probes (lectins, antibodies) to analyze the major glycopolymers of pathogenic and non-pathogenic yeast cells at molecular resolution. We show that non-ubiquitous β-1,2-mannans are largely exposed on the surface of native cells from pathogenic Candida albicans and C. glabrata, the former species displaying the highest glycopolymer density and extensions. We also find that chitin, a major component of the inner layer of the yeast cell wall, is much more abundant in C. albicans. These differences in molecular properties, further supported by flow cytometry measurements, may play an important role in strengthening cell wall mechanics and immune interactions. This study demonstrates that single-molecule AFM, combined with immunological and fluorescence methods, is a powerful platform in fungal glycobiology for probing the density, distribution and extension of specific cell wall glycoconjugates. In nanomedicine, we anticipate that this new form of AFM-based nanoglycobiology will contribute to the development of sugar-based drugs, immunotherapeutics, vaccines and diagnostics.

Molecular breast imaging using a dedicated high-performance instrument

NASA Astrophysics Data System (ADS)

O'Connor, Michael K.; Wagenaar, Douglas; Hruska, Carrie B.; Phillips, Stephen; Caravaglia, Gina; Rhodes, Deborah

2006-08-01

In women with radiographically dense breasts, the sensitivity of mammography is less than 50%. With the increase in the percent of women with dense breasts, it is important to look at alternative screening techniques for this population. This article reviews the strengths and weaknesses of current imaging techniques and focuses on recent developments in semiconductor-based gamma camera systems that offer significant improvements in image quality over that achievable with single-crystal sodium iodide systems. We have developed a technique known as Molecular Breast Imaging (MBI) using small field of view Cadmium Zinc Telluride (CZT) gamma cameras that permits the breast to be imaged in a similar manner to mammography, using light pain-free compression. Computer simulations and experimental studies have shown that use of low-energy high sensitivity collimation coupled with the excellent energy resolution and intrinsic spatial resolution of CZT detectors provides optimum image quality for the detection of small breast lesions. Preliminary clinical studies with a prototype dual-detector system have demonstrated that Molecular Breast Imaging has a sensitivity of ~90% for the detection of breast tumors less than 10 mm in diameter. By comparison, conventional scintimammography only achieves a sensitivity of 50% in the detection of lesions < 10 mm. Because Molecular Breast Imaging is not affected by breast density, this technique may offer an important adjunct to mammography in the evaluation of women with dense breast parenchyma.

Molecular docking sites designed for the generation of highly crystalline covalent organic frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ascherl, Laura; Sick, Torben; Margraf, Johannes

Covalent organic frameworks (COFs) formed by connecting multidentate organic building blocks through covalent bonds provide a platform for designing multifunctional porous materials with atomic precision. As they are promising materials for applications in optoelectronics, they would benefit from a maximum degree of long-range order within the framework, which has remained a major challenge. We have developed a synthetic concept to allow consecutive COF sheets to lock in position during crystal growth, and thus minimize the occurrence of stacking faults and dislocations. Hereby, the three-dimensional conformation of propeller-shaped molecular building units was used to generate well-defined periodic docking sites, which guidedmore » the attachment of successive building blocks that, in turn, promoted long-range order during COF formation. This approach enables us to achieve a very high crystallinity for a series of COFs that comprise tri- and tetradentate central building blocks. We expect this strategy to be transferable to a broad range of customized COFs.« less

Molecular docking sites designed for the generation of highly crystalline covalent organic frameworks

NASA Astrophysics Data System (ADS)

Ascherl, Laura; Sick, Torben; Margraf, Johannes T.; Lapidus, Saul H.; Calik, Mona; Hettstedt, Christina; Karaghiosoff, Konstantin; Döblinger, Markus; Clark, Timothy; Chapman, Karena W.; Auras, Florian; Bein, Thomas

2016-04-01

Covalent organic frameworks (COFs) formed by connecting multidentate organic building blocks through covalent bonds provide a platform for designing multifunctional porous materials with atomic precision. As they are promising materials for applications in optoelectronics, they would benefit from a maximum degree of long-range order within the framework, which has remained a major challenge. We have developed a synthetic concept to allow consecutive COF sheets to lock in position during crystal growth, and thus minimize the occurrence of stacking faults and dislocations. Hereby, the three-dimensional conformation of propeller-shaped molecular building units was used to generate well-defined periodic docking sites, which guided the attachment of successive building blocks that, in turn, promoted long-range order during COF formation. This approach enables us to achieve a very high crystallinity for a series of COFs that comprise tri- and tetradentate central building blocks. We expect this strategy to be transferable to a broad range of customized COFs.

Forensic molecular pathology of violent deaths.

PubMed

Maeda, Hitoshi; Zhu, Bao-li; Ishikawa, Takaki; Michiue, Tomomi

2010-12-15

In forensic pathology, while classical morphology remains a core procedure to investigate deaths, a spectrum of ancillary procedures has been developed and incorporated to detail the pathology. Among them, postmortem biochemistry is important to investigate the systemic pathophysiological changes involved in the dying process that cannot be detected by morphology. In addition, recent advances in molecular biology have provided a procedure to investigate genetic bases of diseases that might present with sudden death, which is called 'molecular autopsy'. Meanwhile, the practical application of RNA analyses to postmortem investigation has not been accepted due to rapid decay after death; however, recent experimental and practical studies using real-time reverse transcription-PCR have suggested that the relative quantification of mRNA transcripts can be applied in molecular pathology for postmortem investigation of deaths, which may be called 'advanced molecular autopsy'. In a broad sense, forensic molecular pathology implies applied medical sciences to investigate the genetic basis of diseases, and the pathophysiology of diseases and traumas leading to death at a biological molecular level in the context of forensic pathology. The possible applications include analyses of local pathology, including tissue injury, ischemia/hypoxia and inflammation at the site of insult or specific tissue damage from intoxication, systemic responses to violence or environmental hazards, disorders due to intoxication, and systemic pathophysiology of fatal process involving major life-support organs. A review of previous studies suggests that systematic postmortem quantitative analysis of mRNA transcripts can be established from multi-faceted aspects of molecular biology and incorporated into death investigations in forensic pathology, to support and reinforce morphological evidence. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Prospective Teachers from Urban Environments Examine Causes of the Achievement Gap in the United States

ERIC Educational Resources Information Center

Morales, Erik E.

2016-01-01

This study analyzes the educational achievement gap between low and high socioeconomic students from the perspective of sixty-two prospective teachers in an undergraduate educational foundations course at a public majority minority urban university in the northeastern United States. The majority of these college students come from, and plan to…

Undergraduates Achieve Learning Gains in Plant Genetics through Peer Teaching of Secondary Students

ERIC Educational Resources Information Center

Chrispeels, H. E.; Klosterman, M. L.; Martin, J. B.; Lundy, S. R.; Watkins, J. M.; Gibson, C. L.; Muday, G. K.

2014-01-01

This study tests the hypothesis that undergraduates who peer teach genetics will have greater understanding of genetic and molecular biology concepts as a result of their teaching experiences. Undergraduates enrolled in a non-majors biology course participated in a service-learning program in which they led middle school (MS) or high school (HS)…

Large-Area, Ensemble Molecular Electronics: Motivation and Challenges.

PubMed

Vilan, Ayelet; Aswal, Dinesh; Cahen, David

2017-03-08

We review charge transport across molecular monolayers, which is central to molecular electronics (MolEl), using large-area junctions (NmJ). We strive to provide a wide conceptual overview of three main subtopics. First, a broad introduction places NmJ in perspective to related fields of research and to single-molecule junctions (1mJ) in addition to a brief historical account. As charge transport presents an ultrasensitive probe for the electronic perfection of interfaces, in the second part ways to form both the monolayer and the contacts are described to construct reliable, defect-free interfaces. The last part is dedicated to understanding and analyses of current-voltage (I-V) traces across molecular junctions. Notwithstanding the original motivation of MolEl, I-V traces are often not very sensitive to molecular details and then provide a poor probe for chemical information. Instead, we focus on how to analyze the net electrical performance of molecular junctions, from a functional device perspective. Finally, we point to creation of a built-in electric field as a key to achieve functionality, including nonlinear current-voltage characteristics that originate in the molecules or their contacts to the electrodes. This review is complemented by a another review that covers metal-molecule-semiconductor junctions and their unique hybrid effects.

Cascading of molecular logic gates for advanced functions: a self-reporting, activatable photosensitizer.

PubMed

Erbas-Cakmak, Sundus; Akkaya, Engin U

2013-10-18

Logical progress: Independent molecular logic gates have been designed and characterized. Then, the individual molecular logic gates were coerced to work together within a micelle. Information relay between the two logic gates was achieved through the intermediacy of singlet oxygen. Working together, these concatenated logic gates result in a self-reporting and activatable photosensitizer. GSH=glutathione. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular genetic transfection of the coccidian parasite Sarcocystis neurona.

PubMed

Gaji, Rajshekhar Y; Zhang, Deqing; Breathnach, Cormac C; Vaishnava, Shipra; Striepen, Boris; Howe, Daniel K

2006-11-01

Sarcocystis neurona is an apicomplexan parasite that is the major cause of equine protozoal myeloencephalitis (EPM). The biology of this pathogen remains poorly understood in part due to unavailability of molecular genetic tools. Hence, with an objective to develop DNA transfection capabilities for S. neurona, the 5' flanking region of the SnSAG1 gene was isolated from a genomic library and used to construct expression plasmids. In transient assays, the reporter molecules beta-galactosidase (beta-gal) and yellow fluorescent protein (YFP) could be detected in electroporated S. neurona, thereby confirming the feasibility of transgene expression in this organism. Stable transformation of S. neurona was achieved using a mutant dihydrofolate reductase thymidylate synthase (DHFR-TS) gene of Toxoplasma gondii that confers resistance to pyrimethamine. This selection system was used to create transgenic S. neurona that stably express beta-gal and YFP. As shown in this study, these transgenic clones can be useful for analyzing growth rate of parasites in vitro and for assessing drug sensitivities. More importantly, the DNA transfection methods described herein should greatly facilitate studies examining intracellular parasitism by this important coccidian pathogen.

Symposium FF: Molecular Motors, Nanomachines, and Active Nanostructures

DTIC Science & Technology

2008-06-23

proof crucial to power future nanomachines.The design of synthetic molecular motors to achieve controlled translational and rotary motion is...switching speeds and fatigue resistances of spiropyrans, we have designed and synthesized a new family of photochromic compounds based on the photoinduced...distance requirements between the two communicating parts. Drawing inspirations from naturally occurring constructs, we have designed and synthesized

Hemimetabolous genomes reveal molecular basis of termite eusociality.

PubMed

Harrison, Mark C; Jongepier, Evelien; Robertson, Hugh M; Arning, Nicolas; Bitard-Feildel, Tristan; Chao, Hsu; Childers, Christopher P; Dinh, Huyen; Doddapaneni, Harshavardhan; Dugan, Shannon; Gowin, Johannes; Greiner, Carolin; Han, Yi; Hu, Haofu; Hughes, Daniel S T; Huylmans, Ann-Kathrin; Kemena, Carsten; Kremer, Lukas P M; Lee, Sandra L; Lopez-Ezquerra, Alberto; Mallet, Ludovic; Monroy-Kuhn, Jose M; Moser, Annabell; Murali, Shwetha C; Muzny, Donna M; Otani, Saria; Piulachs, Maria-Dolors; Poelchau, Monica; Qu, Jiaxin; Schaub, Florentine; Wada-Katsumata, Ayako; Worley, Kim C; Xie, Qiaolin; Ylla, Guillem; Poulsen, Michael; Gibbs, Richard A; Schal, Coby; Richards, Stephen; Belles, Xavier; Korb, Judith; Bornberg-Bauer, Erich

2018-03-01

Around 150 million years ago, eusocial termites evolved from within the cockroaches, 50 million years before eusocial Hymenoptera, such as bees and ants, appeared. Here, we report the 2-Gb genome of the German cockroach, Blattella germanica, and the 1.3-Gb genome of the drywood termite Cryptotermes secundus. We show evolutionary signatures of termite eusociality by comparing the genomes and transcriptomes of three termites and the cockroach against the background of 16 other eusocial and non-eusocial insects. Dramatic adaptive changes in genes underlying the production and perception of pheromones confirm the importance of chemical communication in the termites. These are accompanied by major changes in gene regulation and the molecular evolution of caste determination. Many of these results parallel molecular mechanisms of eusocial evolution in Hymenoptera. However, the specific solutions are remarkably different, thus revealing a striking case of convergence in one of the major evolutionary transitions in biological complexity.

Molecular regulation of plant cell wall extensibility

NASA Technical Reports Server (NTRS)

Cosgrove, D. J.

1998-01-01

Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

Molecular biology of pancreatic cancer.

PubMed

Zavoral, Miroslav; Minarikova, Petra; Zavada, Filip; Salek, Cyril; Minarik, Marek

2011-06-28

In spite of continuous research efforts directed at early detection and treatment of pancreatic cancer, the outlook for patients affected by the disease remains dismal. With most cases still being diagnosed at advanced stages, no improvement in survival prognosis is achieved with current diagnostic imaging approaches. In the absence of a dominant precancerous condition, several risk factors have been identified including family history, chronic pancreatitis, smoking, diabetes mellitus, as well as certain genetic disorders such as hereditary pancreatitis, cystic fibrosis, familial atypical multiple mole melanoma, and Peutz-Jeghers and Lynch syndromes. Most pancreatic carcinomas, however, remain sporadic. Current progress in experimental molecular techniques has enabled detailed understanding of the molecular processes of pancreatic cancer development. According to the latest information, malignant pancreatic transformation involves multiple oncogenes and tumor-suppressor genes that are involved in a variety of signaling pathways. The most characteristic aberrations (somatic point mutations and allelic losses) affect oncogenes and tumor-suppressor genes within RAS, AKT and Wnt signaling, and have a key role in transcription and proliferation, as well as systems that regulate the cell cycle (SMAD/DPC, CDKN2A/p16) and apoptosis (TP53). Understanding of the underlying molecular mechanisms should promote development of new methodology for early diagnosis and facilitate improvement in current approaches for pancreatic cancer treatment.

A multiscale simulation technique for molecular electronics: design of a directed self-assembled molecular n-bit shift register memory device.

PubMed

Lambropoulos, Nicholas A; Reimers, Jeffrey R; Crossley, Maxwell J; Hush, Noel S; Silverbrook, Kia

2013-12-20

A general method useful in molecular electronics design is developed that integrates modelling on the nano-scale (using quantum-chemical software) and on the micro-scale (using finite-element methods). It is applied to the design of an n-bit shift register memory that could conceivably be built using accessible technologies. To achieve this, the entire complex structure of the device would be built to atomic precision using feedback-controlled lithography to provide atomic-level control of silicon devices, controlled wet-chemical synthesis of molecular insulating pillars above the silicon, and controlled wet-chemical self-assembly of modular molecular devices to these pillars that connect to external metal electrodes (leads). The shift register consists of n connected cells that read data from an input electrode, pass it sequentially between the cells under the control of two external clock electrodes, and deliver it finally to an output device. The proposed cells are trimeric oligoporphyrin units whose internal states are manipulated to provide functionality, covalently connected to other cells via dipeptide linkages. Signals from the clock electrodes are conveyed by oligoporphyrin molecular wires, and μ-oxo porphyrin insulating columns are used as the supporting pillars. The developed multiscale modelling technique is applied to determine the characteristics of this molecular device, with in particular utilization of the inverted region for molecular electron-transfer processes shown to facilitate latching and control using exceptionally low energy costs per logic operation compared to standard CMOS shift register technology.

A multiscale simulation technique for molecular electronics: design of a directed self-assembled molecular n-bit shift register memory device

NASA Astrophysics Data System (ADS)

Lambropoulos, Nicholas A.; Reimers, Jeffrey R.; Crossley, Maxwell J.; Hush, Noel S.; Silverbrook, Kia

2013-12-01

A general method useful in molecular electronics design is developed that integrates modelling on the nano-scale (using quantum-chemical software) and on the micro-scale (using finite-element methods). It is applied to the design of an n-bit shift register memory that could conceivably be built using accessible technologies. To achieve this, the entire complex structure of the device would be built to atomic precision using feedback-controlled lithography to provide atomic-level control of silicon devices, controlled wet-chemical synthesis of molecular insulating pillars above the silicon, and controlled wet-chemical self-assembly of modular molecular devices to these pillars that connect to external metal electrodes (leads). The shift register consists of n connected cells that read data from an input electrode, pass it sequentially between the cells under the control of two external clock electrodes, and deliver it finally to an output device. The proposed cells are trimeric oligoporphyrin units whose internal states are manipulated to provide functionality, covalently connected to other cells via dipeptide linkages. Signals from the clock electrodes are conveyed by oligoporphyrin molecular wires, and μ-oxo porphyrin insulating columns are used as the supporting pillars. The developed multiscale modelling technique is applied to determine the characteristics of this molecular device, with in particular utilization of the inverted region for molecular electron-transfer processes shown to facilitate latching and control using exceptionally low energy costs per logic operation compared to standard CMOS shift register technology.

PMG: online generation of high-quality molecular pictures and storyboarded animations

PubMed Central

Autin, Ludovic; Tufféry, Pierre

2007-01-01

The Protein Movie Generator (PMG) is an online service able to generate high-quality pictures and animations for which one can then define simple storyboards. The PMG can therefore efficiently illustrate concepts such as molecular motion or formation/dissociation of complexes. Emphasis is put on the simplicity of animation generation. Rendering is achieved using Dino coupled to POV-Ray. In order to produce highly informative images, the PMG includes capabilities of using different molecular representations at the same time to highlight particular molecular features. Moreover, sophisticated rendering concepts including scene definition, as well as modeling light and materials are available. The PMG accepts Protein Data Bank (PDB) files as input, which may include series of models or molecular dynamics trajectories and produces images or movies under various formats. PMG can be accessed at http://bioserv.rpbs.jussieu.fr/PMG.html. PMID:17478496

The Impact of Principal Leadership on School Culture and Student Achievement

ERIC Educational Resources Information Center

Troutman, Lisa Dorman

2012-01-01

Throughout the United States school principals are subject to increasingly high demands for student accountability. Under the pressures and mandates of this federal legislation, principals are asking themselves what specific leadership practices affect student achievement. A review of literature shows that principals are regarded as a major factor…

Symbolic programming language in molecular multicenter integral problem

NASA Astrophysics Data System (ADS)

Safouhi, Hassan; Bouferguene, Ahmed

It is well known that in any ab initio molecular orbital (MO) calculation, the major task involves the computation of molecular integrals, among which the computation of three-center nuclear attraction and Coulomb integrals is the most frequently encountered. As the molecular system becomes larger, computation of these integrals becomes one of the most laborious and time-consuming steps in molecular systems calculation. Improvement of the computational methods of molecular integrals would be indispensable to further development in computational studies of large molecular systems. To develop fast and accurate algorithms for the numerical evaluation of these integrals over B functions, we used nonlinear transformations for improving convergence of highly oscillatory integrals. These methods form the basis of new methods for solving various problems that were unsolvable otherwise and have many applications as well. To apply these nonlinear transformations, the integrands should satisfy linear differential equations with coefficients having asymptotic power series in the sense of Poincaré, which in their turn should satisfy some limit conditions. These differential equations are very difficult to obtain explicitly. In the case of molecular integrals, we used a symbolic programming language (MAPLE) to demonstrate that all the conditions required to apply these nonlinear transformation methods are satisfied. Differential equations are obtained explicitly, allowing us to demonstrate that the limit conditions are also satisfied.

Male Saudi Arabian Freshman Science Majors at Jazan University: Their Perceptions of Parental Educational Practices on Their Science Achievements

ERIC Educational Resources Information Center

Alrehaly, Essa D.

2012-01-01

Examination of Saudi Arabian educational practices is scarce, but increasingly important, especially in light of the country's pace in worldwide mathematics and science rankings. The purpose of the study is to understand and evaluate parental influence on male children's science education achievements in Saudi Arabia. Parental level of education…

Black Molecular Adsorber Coatings for Spaceflight Applications

NASA Technical Reports Server (NTRS)

Abraham, Nithin Susan; Hasegawa, Mark Makoto; Straka, Sharon A.

2014-01-01

The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

[Relevance of big data for molecular diagnostics].

PubMed

Bonin-Andresen, M; Smiljanovic, B; Stuhlmüller, B; Sörensen, T; Grützkau, A; Häupl, T

2018-04-01

Big data analysis raises the expectation that computerized algorithms may extract new knowledge from otherwise unmanageable vast data sets. What are the algorithms behind the big data discussion? In principle, high throughput technologies in molecular research already introduced big data and the development and application of analysis tools into the field of rheumatology some 15 years ago. This includes especially omics technologies, such as genomics, transcriptomics and cytomics. Some basic methods of data analysis are provided along with the technology, however, functional analysis and interpretation requires adaptation of existing or development of new software tools. For these steps, structuring and evaluating according to the biological context is extremely important and not only a mathematical problem. This aspect has to be considered much more for molecular big data than for those analyzed in health economy or epidemiology. Molecular data are structured in a first order determined by the applied technology and present quantitative characteristics that follow the principles of their biological nature. These biological dependencies have to be integrated into software solutions, which may require networks of molecular big data of the same or even different technologies in order to achieve cross-technology confirmation. More and more extensive recording of molecular processes also in individual patients are generating personal big data and require new strategies for management in order to develop data-driven individualized interpretation concepts. With this perspective in mind, translation of information derived from molecular big data will also require new specifications for education and professional competence.

Black molecular adsorber coatings for spaceflight applications

NASA Astrophysics Data System (ADS)

Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

2014-09-01

The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

Resolved Parental Infertility and Children's Educational Achievement.

PubMed

Branigan, Amelia R; Helgertz, Jonas

2017-06-01

Although difficulty conceiving a child has long been a major medical and social preoccupation, it has not been considered as a predictor of long-term outcomes in children ultimately conceived. This is consistent with a broader gap in knowledge regarding the consequences of parental health for educational performance in offspring. Here we address that omission, asking how resolved parental infertility relates to children's academic achievement. In a sample of all Swedish births between 1988 and 1995, we find that involuntary childlessness prior to either a first or a second birth is associated with lower academic achievement (both test scores and GPA) in children at age 16, even if the period of infertility was prior to a sibling's birth rather than the child's own. Our results support a conceptualization of infertility as a cumulative physical and social experience with effects extending well beyond the point at which a child is born, and emphasize the need to better understand how specific parental health conditions constrain children's educational outcomes.

Enzymatic and acidic degradation of high molecular weight dextran into low molecular weight and its characterizations using novel Diffusion-ordered NMR spectroscopy.

PubMed

Iqbal, Samina; Marchetti, Roberta; Aman, Afsheen; Silipo, Alba; Qader, Shah Ali Ul; Molinaro, Antonio

2017-10-01

Low molecular weight fractions were derived from native high molecular weight dextran produced by Leuconostoc mesenteroides KIBGE-IB26. Structural characterization of native and low molecular weight fractions obtained after acidic and enzymatic hydrolysis was done using FTIR and NMR spectroscopy. The molecular weight was estimated using Diffusion Ordered NMR spectroscopy. Native dextran (892kDa) is composed of α-(1→6) glycosidic linkage along with α-(1→3) branching. Major proportion of 528kDa dextran was obtained after prolong enzymatic hydrolysis however, an effective acidic treatment at pH-1.4 up to 02 and 04h of exposure resulted in the formation of 77kDa and 57kDa, respectively. The increment in pH from 1.4 to 1.8 lowered the hydrolysis efficiency and resulted in the formation of 270kDa dextran fraction. The results suggest that derived low molecular weight water soluble fractions can be utilized as a drug delivery carrier along with multiple application relating pharmaceutical industries. Copyright © 2017 Elsevier B.V. All rights reserved.

Lysozyme oxidation by singlet molecular oxygen: Peptide characterization using [18 O]-labeling oxygen and nLC-MS/MS.

PubMed

Marques, Emerson Finco; Medeiros, Marisa H G; Di Mascio, Paolo

2017-11-01

Singlet molecular oxygen ( 1 O 2 ) is generated in biological systems and reacts with different biomolecules. Proteins are a major target for 1 O 2 , and His, Tyr, Met, Cys, and Trp are oxidized at physiological pH. In the present study, the modification of lysozyme protein by 1 O 2 was investigated using mass spectrometry approaches. The experimental findings showed methionine, histidine, and tryptophan oxidation. The experiments were achieved using [ 18 O]-labeled 1 O 2 released from thermolabile endoperoxides in association with nano-scale liquid chromatography coupled to electrospray ionization mass spectrometry. The structural characterization by nLC-MS/MS of the amino acids in the tryptic peptides of the proteins showed addition of [ 18 O]-labeling atoms in different amino acids. Copyright © 2017 John Wiley & Sons, Ltd.

Monitoring pyrethroid insecticide resistance in major malaria vector Anopheles culicifacies: comparison of molecular tools and conventional susceptibility test.

PubMed

Djadid, Navid Dinparast; Forouzesh, Flora; Karimi, Mohsen; Raeisi, Ahmad; Hassan-Zehi, Abdoulghaffar; Zakeri, Sedigheh

2007-07-01

Anopheles culicifacies is a main malaria vector in southeastern part of Iran, bordring Afghanistan and Pakistan. So far, resistance to DDT, dieldrin, malathion and partial tolerance to pyrethroids has been reported in An. stephensi, but nothing confirmed on resistance status of An. culicifacies in Iran. In current study, along with WHO routine susceptibility test with DDT (4%), dieldrin (0.4%), malathion (5%), permethrin (0.25%), lambadacyhalothrin (0.1%), and deltamethrin 0.025, we cloned and sequenced segment VI of domain II (SII6) in voltage-gated sodium channel (vgsc) gene of An. culicifacies specimens collected in Sistan and Baluchistan province (Iran). A 221-bp amplified fragment showed 91% and 93% similarity with exon I and exon II of An. gambiae. The size of intron II in An. culicifacies is 62 bp, while in An. gambiae is 57 bp. The major difference within An. culicifacies specimens and also with An. gambiae is in position 29 of exon I, which led to substitution of Leu to His amino acid. This data will act as first report on partial sequence of vgsc gene and its polymorphism in An. culicifacies. A Leu to His amino acid substitution detected upstream the formerly known knockdown resistance (kdr) mutation site could be an indication for other possible mutations related to insecticide resistance. However, the result of WHO susceptibility test carried out in Baluchistan of Iran revealed a level of tolerance to DDT and dieldrin, but almost complete susceptibility to pyrethroids in An. culicifacies. We postulate that the molecular diagnostic tool developed for detection and identification of kdr-related mutations in An. culicifacies, could be useful in monitoring insecticide resistance in Iran and neighbouring countries such as Pakistan and Afghanistan. A phylogenetic tree also constructed based on the sequence of exon I and II, which readily separated An. culicifacies populations from An. stephensi, An. fluviatilis and An. gambiae.

Controlling molecular transport in minimal emulsions

NASA Astrophysics Data System (ADS)

Gruner, Philipp; Riechers, Birte; Semin, Benoît; Lim, Jiseok; Johnston, Abigail; Short, Kathleen; Baret, Jean-Christophe

2016-01-01

Emulsions are metastable dispersions in which molecular transport is a major mechanism driving the system towards its state of minimal energy. Determining the underlying mechanisms of molecular transport between droplets is challenging due to the complexity of a typical emulsion system. Here we introduce the concept of `minimal emulsions', which are controlled emulsions produced using microfluidic tools, simplifying an emulsion down to its minimal set of relevant parameters. We use these minimal emulsions to unravel the fundamentals of transport of small organic molecules in water-in-fluorinated-oil emulsions, a system of great interest for biotechnological applications. Our results are of practical relevance to guarantee a sustainable compartmentalization of compounds in droplet microreactors and to design new strategies for the dynamic control of droplet compositions.

Molecular Mechanisms Associated with Xylan Degradation by Xanthomonas Plant Pathogens*

PubMed Central

Santos, Camila Ramos; Hoffmam, Zaira Bruna; de Matos Martins, Vanesa Peixoto; Zanphorlin, Leticia Maria; de Paula Assis, Leandro Henrique; Honorato, Rodrigo Vargas; Lopes de Oliveira, Paulo Sérgio; Ruller, Roberto; Murakami, Mario Tyago

2014-01-01

Xanthomonas pathogens attack a variety of economically relevant plants, and their xylan CUT system (carbohydrate utilization with TonB-dependent outer membrane transporter system) contains two major xylanase-related genes, xynA and xynB, which influence biofilm formation and virulence by molecular mechanisms that are still elusive. Herein, we demonstrated that XynA is a rare reducing end xylose-releasing exo-oligoxylanase and not an endo-β-1,4-xylanase as predicted. Structural analysis revealed that an insertion in the β7-α7 loop induces dimerization and promotes a physical barrier at the +2 subsite conferring this unique mode of action within the GH10 family. A single mutation that impaired dimerization became XynA active against xylan, and high endolytic activity was achieved when this loop was tailored to match a canonical sequence of endo-β-1,4-xylanases, supporting our mechanistic model. On the other hand, the divergent XynB proved to be a classical endo-β-1,4-xylanase, despite the low sequence similarity to characterized GH10 xylanases. Interestingly, this enzyme contains a calcium ion bound nearby to the glycone-binding region, which is required for catalytic activity and structural stability. These results shed light on the molecular basis for xylan degradation by Xanthomonas and suggest how these enzymes synergistically assist infection and pathogenesis. Our findings indicate that XynB contributes to breach the plant cell wall barrier, providing nutrients and facilitating the translocation of effector molecules, whereas the exo-oligoxylanase XynA possibly participates in the suppression of oligosaccharide-induced immune responses. PMID:25266726

Online High School Achievement versus Traditional High School Achievement

ERIC Educational Resources Information Center

Blohm, Katherine E.

2017-01-01

The following study examined the question of student achievement in online charter schools and how the achievement scores of students at online charter schools compare to achievement scores of students at traditional schools. Arizona has seen explosive growth in charter schools and online charter schools. A study comparing how these two types of…

Why I Believe I Achieve Determines Whether I Achieve

ERIC Educational Resources Information Center

Siegle, Del; McCoach, D. Betsy; Roberts, Anne

2017-01-01

The beliefs and values students hold toward themselves, given tasks, and achievement itself can influence what tasks students seek, and whether they are able to obtain them. On the basis of previous research on underachievement and motivation, we developed the Achievement Orientation Model (AOM) to explore the issue of student achievement. The…

Targeting Leishmania major parasite with peptides derived from a combinatorial phage display library.

PubMed

Rhaiem, Rafik Ben; Houimel, Mehdi

2016-07-01

Cutaneous leishmaniasis (CL) is a global problem caused by intracellular protozoan pathogens of the genus Leishmania for which there are no suitable vaccine or chemotherapy options. Thus, de novo identification of small molecules binding to the Leishmania parasites by direct screening is a promising and appropriate alternative strategy for the development of new drugs. In this study, we used a random linear hexapeptide library fused to the gene III protein of M13 filamentous bacteriophage to select binding peptides to metacyclic promastigotes from a highly virulent strain of Leishmania major (Zymodeme MON-25; MHOM/TN/94/GLC94). After four rounds of stringent selection and amplification, polyclonal and monoclonal phage-peptides directed against L. major metacyclic promastigotes were assessed by ELISA, and the optimal phage-peptides were grown individually and characterized for binding to L. major by monoclonal phage ELISA. The DNA of 42 phage-peptides clones was amplified by PCR, sequenced, and their amino acid sequences deduced. Six different peptide sequences were obtained with frequencies of occurrence ranging from 2.3% to 85.7%. The biological effect of the peptides was assessed in vitro on human monocytes infected with L. major metacyclic promastigotes, and in vivo on susceptible parasite-infected BALB/c mice. The development of cutaneous lesions in the right hind footpads of infected mice after 13 weeks post-infection showed a protection rate of 81.94% with the injected peptide P2. Moreover, Western blots revealed that the P2 peptide interacted with the major surface protease gp63, a protein of 63kDa molecular weight. Moreover, bioinformatics were used to predict the interaction between peptides and the major surface molecule of the L. major. The molecular docking showed that the P2 peptide has the minimum interaction energy and maximum shape complimentarity with the L. major gp63 active site. Our study demonstrated that the P2 peptide occurs at high frequency

Absolute molecular sieve separation of ethylene/ethane mixtures with silver zeolite A.

PubMed

Aguado, Sonia; Bergeret, Gérard; Daniel, Cecile; Farrusseng, David

2012-09-12

Absolute ethylene/ethane separation is achieved by ethane exclusion on silver-exchanged zeolite A adsorbent. This molecular sieving type separation is attributed to the pore size of the adsorbent, which falls between ethylene and ethane kinetic diameters.

Personality Characteristics and Choice of Academic Major: Are Traditional Stereotypes Obsolete?

ERIC Educational Resources Information Center

Pringle, Charles D.; DuBose, Philip B.; Yankey, Michael D.

2010-01-01

Among the many reasons for choosing an academic major are stereotypes that students hold of particular occupations and the degree to which they believe that their personalities match those stereotypes. We examined relevant personality characteristics (i.e., achievement motivation, conformity, conscientiousness, creativity and extroversion) of 899…

In situ molecular elucidation of drug supersaturation achieved by nano-sizing and amorphization of poorly water-soluble drug.

PubMed

Ueda, Keisuke; Higashi, Kenjirou; Yamamoto, Keiji; Moribe, Kunikazu

2015-09-18

Quantitative evaluation of drug supersaturation and nanoparticle formation was conducted using in situ evaluation techniques, including nuclear magnetic resonance (NMR) spectroscopy. We prepared a ternary complex of carbamazepine (CBZ) with hydroxypropyl methylcellulose (HPMC) and sodium dodecyl sulfate (SDS) to improve the drug concentration. Different preparation methods, including grinding and spray drying, were performed to prepare the ternary component products, ground mixture (GM) and spray-dried sample (SD), respectively. Although CBZ was completely amorphized in the ternary SD, CBZ was partially amorphized with the remaining CBZ crystals in the ternary GM. Aqueous dispersion of the ternary GM formed nanoparticles of around 150 nm, originating from the CBZ crystals in the ternary GM. In contrast, the ternary SD formed transparent solutions without a precipitate. The molecular-level evaluation using NMR measurements revealed that approximately half a dose of CBZ in the ternary GM dispersion was present as nanoparticles; however, CBZ in the ternary SD was completely dissolved in the aqueous solution. The characteristic difference between the solid states, followed by different preparation methods, induced different solution characteristics in the ternary GM and SD. The permeation study, using a dialysis membrane, showed that the CBZ concentration dissolved in the bulk water phase rapidly reduced in the ternary SD dispersion compared to the ternary GM dispersion; this demonstrated the advantage of ternary GM dispersion in the maintenance of CBZ supersaturation. Long-term maintenance of a supersaturated state of CBZ observed in the ternary GM dispersion rather than in the ternary SD dispersion was achieved by the inhibition of CBZ crystallization owing to the existence of CBZ nanoparticles in the ternary GM dispersion. Nanoparticle formation, combined with drug amorphization, could be a promising approach to improve drug concentrations. The detailed elucidation

Polarizable Molecular Dynamics in a Polarizable Continuum Solvent

PubMed Central

Lipparini, Filippo; Lagardère, Louis; Raynaud, Christophe; Stamm, Benjamin; Cancès, Eric; Mennucci, Benedetta; Schnieders, Michael; Ren, Pengyu; Maday, Yvon; Piquemal, Jean-Philip

2015-01-01

We present for the first time scalable polarizable molecular dynamics (MD) simulations within a polarizable continuum solvent with molecular shape cavities and exact solution of the mutual polarization. The key ingredients are a very efficient algorithm for solving the equations associated with the polarizable continuum, in particular, the domain decomposition Conductor-like Screening Model (ddCOSMO), a rigorous coupling of the continuum with the polarizable force field achieved through a robust variational formulation and an effective strategy to solve the coupled equations. The coupling of ddCOSMO with non variational force fields, including AMOEBA, is also addressed. The MD simulations are feasible, for real life systems, on standard cluster nodes; a scalable parallel implementation allows for further speed up in the context of a newly developed module in Tinker, named Tinker-HP. NVE simulations are stable and long term energy conservation can be achieved. This paper is focused on the methodological developments, on the analysis of the algorithm and on the stability of the simulations; a proof-of-concept application is also presented to attest the possibilities of this newly developed technique. PMID:26516318

Grafting of molecularly imprinted polymer to porous polyethylene filtration membranes by plasma polymerization.

PubMed

Cowieson, D; Piletska, E; Moczko, E; Piletsky, S

2013-08-01

An application of plasma-induced grafting of polyethylene membranes with a thin layer of molecularly imprinted polymer (MIP) was presented. High-density polyethylene (HDPE) membranes, "Vyon," were used as a substrate for plasma grafting modification. The herbicide atrazine, one of the most popular targets of the molecular imprinting, was chosen as a template. The parameters of the plasma treatment were optimized in order to achieve a good balance between polymerization and ablation processes. Modified HDPE membranes were characterized, and the presence of the grafted polymeric layer was confirmed based on the observed weight gain, pore size measurements, and infrared spectrometry. Since there was no significant change in the porosity of the modified membranes, it was assumed that only a thin layer of the polymer was introduced on the surface. The experiments on the re-binding of the template atrazine to the membranes modified with MIP and blank polymers were performed. HDPE membranes which were grafted with polymer using continuous plasma polymerization demonstrated the best result which was expressed in an imprinted factor equal to 3, suggesting that molecular imprinting was successfully achieved.

Engineering Yarrowia lipolytica for Use in Biotechnological Applications: A Review of Major Achievements and Recent Innovations.

PubMed

Madzak, Catherine

2018-06-25

Yarrowia lipolytica is an oleaginous saccharomycetous yeast with a long history of industrial use. It aroused interest several decades ago as host for heterologous protein production. Thanks to the development of numerous molecular and genetic tools, Y. lipolytica is now a recognized system for expressing heterologous genes and secreting the corresponding proteins of interest. As genomic and transcriptomic tools increased our basic knowledge on this yeast, we can now envision engineering its metabolic pathways for use as whole-cell factory in various bioconversion processes. Y. lipolytica is currently being developed as a workhorse for biotechnology, notably for single-cell oil production and upgrading of industrial wastes into valuable products. As it becomes more and more difficult to keep up with an ever-increasing literature on Y. lipolytica engineering technology, this article aims to provide basic and actualized knowledge on this research area. The most useful reviews on Y. lipolytica biology, use, and safety will be evoked, together with a resume of the engineering tools available in this yeast. This mini-review will then focus on recently developed tools and engineering strategies, with a particular emphasis on promoter tuning, metabolic pathways assembly, and genome editing technologies.

Attendance and Achievement in Problem-Based Learning: The Value of Scaffolding

ERIC Educational Resources Information Center

Smith, Mike; Cook, Kathryn

2012-01-01

The impact of problem-based learning (PBL) in improving academic achievement comparedwith other forms of teaching is equivocal. This paper argues that poor tutorial preparation and vague reporting of the brainstorming stage of PBL are major contributing factors. To address these issues this study incorporated a scaffolding mechanism into the…

Molecular processes in a high temperature shock layer

NASA Technical Reports Server (NTRS)

Guberman, S. L.

1984-01-01

Models of the shock layer encountered by an Aeroassisted Orbital Transfer Vehicle require as input accurate cross sections and rate constants for the atomic and molecular processes that characterize the shock radiation. From the estimated atomic and molecular densities in the shock layer and the expected residence time of 1 m/s, it can be expected that electron-ion collision processes will be important in the shock model. Electron capture by molecular ions followed by dissociation, e.g., O2(+) + e(-) yields 0 + 0, can be expected to be of major importance since these processes are known to have high rates (e.g., 10 to the -7th power cu/cm/sec) at room temperature. However, there have been no experimental measurements of dissociative recombination (DR) at temperatures ( 12000K) that are expected to characterize the shock layer. Indeed, even at room temperature, it is often difficult to perform experiments that determine the dependence of the translational energy and quantum yields of the product atoms on the electronic and vibrational state of the reactant molecular ions. Presented are ab initio quantum chemical studies of DR for molecular ions that are likely to be important in the atmospheric shock layer.

Synthetic Molecular Machines for Active Self-Assembly: Prototype Algorithms, Designs, and Experimental Study

NASA Astrophysics Data System (ADS)

Dabby, Nadine L.

Computer science and electrical engineering have been the great success story of the twentieth century. The neat modularity and mapping of a language onto circuits has led to robots on Mars, desktop computers and smartphones. But these devices are not yet able to do some of the things that life takes for granted: repair a scratch, reproduce, regenerate, or grow exponentially fast--all while remaining functional. This thesis explores and develops algorithms, molecular implementations, and theoretical proofs in the context of "active self-assembly" of molecular systems. The long-term vision of active self-assembly is the theoretical and physical implementation of materials that are composed of reconfigurable units with the programmability and adaptability of biology's numerous molecular machines. En route to this goal, we must first find a way to overcome the memory limitations of molecular systems, and to discover the limits of complexity that can be achieved with individual molecules. One of the main thrusts in molecular programming is to use computer science as a tool for figuring out what can be achieved. While molecular systems that are Turing-complete have been demonstrated [Winfree, 1996], these systems still cannot achieve some of the feats biology has achieved. One might think that because a system is Turing-complete, capable of computing "anything," that it can do any arbitrary task. But while it can simulate any digital computational problem, there are many behaviors that are not "computations" in a classical sense, and cannot be directly implemented. Examples include exponential growth and molecular motion relative to a surface. Passive self-assembly systems cannot implement these behaviors because (a) molecular motion relative to a surface requires a source of fuel that is external to the system, and (b) passive systems are too slow to assemble exponentially-fast-growing structures. We call these behaviors "energetically incomplete" programmable

Treating the Synapse in Major Psychiatric Disorders: The Role of Postsynaptic Density Network in Dopamine-Glutamate Interplay and Psychopharmacologic Drugs Molecular Actions

PubMed Central

Tomasetti, Carmine; Iasevoli, Felice; Buonaguro, Elisabetta Filomena; De Berardis, Domenico; Fornaro, Michele; Fiengo, Annastasia Lucia Carmela; Martinotti, Giovanni; Orsolini, Laura; Valchera, Alessandro; Di Giannantonio, Massimo; de Bartolomeis, Andrea

2017-01-01

Dopamine-glutamate interplay dysfunctions have been suggested as pathophysiological key determinants of major psychotic disorders, above all schizophrenia and mood disorders. For the most part, synaptic interactions between dopamine and glutamate signaling pathways take part in the postsynaptic density, a specialized ultrastructure localized under the membrane of glutamatergic excitatory synapses. Multiple proteins, with the role of adaptors, regulators, effectors, and scaffolds compose the postsynaptic density network. They form structural and functional crossroads where multiple signals, starting at membrane receptors, are received, elaborated, integrated, and routed to appropriate nuclear targets. Moreover, transductional pathways belonging to different receptors may be functionally interconnected through postsynaptic density molecules. Several studies have demonstrated that psychopharmacologic drugs may differentially affect the expression and function of postsynaptic genes and proteins, depending upon the peculiar receptor profile of each compound. Thus, through postsynaptic network modulation, these drugs may induce dopamine-glutamate synaptic remodeling, which is at the basis of their long-term physiologic effects. In this review, we will discuss the role of postsynaptic proteins in dopamine-glutamate signals integration, as well as the peculiar impact of different psychotropic drugs used in clinical practice on postsynaptic remodeling, thereby trying to point out the possible future molecular targets of “synapse-based” psychiatric therapeutic strategies. PMID:28085108

Evaluation of molecular brain changes associated with environmental stress in rodent models compared to human major depressive disorder: A proteomic systems approach.

PubMed

Cox, David Alan; Gottschalk, Michael Gerd; Stelzhammer, Viktoria; Wesseling, Hendrik; Cooper, Jason David; Bahn, Sabine

2016-11-25

Rodent models of major depressive disorder (MDD) are indispensable when screening for novel treatments, but assessing their translational relevance with human brain pathology has proved difficult. Using a novel systems approach, proteomics data obtained from post-mortem MDD anterior prefrontal cortex tissue (n = 12) and matched controls (n = 23) were compared with equivalent data from three commonly used preclinical models exposed to environmental stressors (chronic mild stress, prenatal stress and social defeat). Functional pathophysiological features associated with depression-like behaviour were identified in these models through enrichment of protein-protein interaction networks. A cross-species comparison evaluated which model(s) represent human MDD pathology most closely. Seven functional domains associated with MDD and represented across at least two models such as "carbohydrate metabolism and cellular respiration" were identified. Through statistical evaluation using kernel-based machine learning techniques, the social defeat model was found to represent MDD brain changes most closely for four of the seven domains. This is the first study to apply a method for directly evaluating the relevance of the molecular pathology of multiple animal models to human MDD on the functional level. The methodology and findings outlined here could help to overcome translational obstacles of preclinical psychiatric research.

Influence of platelet aspect ratio on the mechanical behaviour of bio-inspired nanocomposites using molecular dynamics.

PubMed

Mathiazhagan, S; Anup, S

2016-06-01

Superior mechanical properties of biocomposites such as nacre and bone are attributed to their basic building blocks. These basic building blocks have nanoscale features and play a major role in achieving combined stiffening, strengthening and toughening mechanisms. Bioinspired nanocomposites based on these basic building blocks, regularly and stairwise staggered arrangements of hard platelets in soft matrix, have huge potential for developing advanced materials. The study of applicability of mechanical principles of biological materials to engineered materials will guide designing advanced materials. To probe the generic mechanical characteristics of these bioinspired nanocomposites, the model material concept in molecular dynamics (MD) is used. In this paper, the effect of platelets aspect ratio (AR) on the mechanical behaviour of bioinspired nanocomposites is investigated. The obtained Young׳s moduli of both the models and the strengths of the regularly staggered models agree with the available theories. However, the strengths of the stairwise staggered models show significant difference. For the stairwise staggered model, we demonstrate the existence of two critical ARs, a smaller critical AR above which platelet fracture occurs and a higher critical AR above which composite strength remains constant. Our MD study also shows the existence of mechanisms of platelet pull-out and breakage for lower and higher ARs. Pullout mechanism acts as a major source of plasticity. Further, we find that the regularly staggered model can achieve an optimal combination of high Young׳s modulus, flow strength and toughness, and the stairwise staggered model is efficient in obtaining high Young׳s modulus and tensile strength. Copyright © 2015 Elsevier Ltd. All rights reserved.

Building strong bones: molecular regulation of the osteoblast lineage.

PubMed

Long, Fanxin

2011-12-22

The past 15 years have witnessed tremendous progress in the molecular understanding of osteoblasts, the main bone-forming cells in the vertebrate skeleton. In particular, all of the major developmental signals (including WNT and Notch signalling), along with an increasing number of transcription factors (such as RUNX2 and osterix), have been shown to regulate the differentiation and/or function of osteoblasts. As evidence indicates that osteoblasts may also regulate the behaviour of other cell types, a clear understanding of the molecular identity and regulation of osteoblasts is important beyond the field of bone biology.

Molecular and immunological characterization of subtilisin like serine protease, a major allergen of Curvularia lunata.

PubMed

Tripathi, Prabhanshu; Nair, Smitha; Singh, B P; Arora, Naveen

2011-03-01

Serine protease from numerous sources have been identified and characterized as major allergens. The present study aimed to clone, express and characterize a serine protease from Curvularia lunata. cDNA library screening identified partial protease clones. A clone showed significant homology to subtilisin like serine proteases from Aspergillus and Penicillium species. Full length sequence was generated by RACE PCR, subcloned in pET vector, protein expressed in Escherichia coli and purified from inclusion bodies yielding 0.5 mg/L of culture. Bioinformatic analysis identified serine protease motifs of subtilase family, catalytic triad and N-glycosylation sites on the primary sequence. The protein resolved at 54-kDa on SDS-PAGE and was recognized as a major allergen on immunoblot with 13/16 C. lunata sensitive patients' sera in ELISA and immunoblot. Recombinant protein reacted with rabbit polyclonal antibodies against alkaline serine proteases from C. lunata. Recombinant protein required 50-56 ng of same protein for 50% inhibition of IgE binding in competitive ELISA. In addition, 13 of 16 patients' samples showed significant basophil histamine release upon stimulation with purified recombinant protein. In conclusion, a 54 kDa major allergen of C. lunata was cloned, expressed, characterized and showed biological activity. It has potential to be used in molecule based approach for allergy diagnosis and therapy. Copyright © 2010 Elsevier GmbH. All rights reserved.

Increasing Persistence in Undergraduate Science Majors: A Model for Institutional Support of Underrepresented Students

PubMed Central

Toven-Lindsey, Brit; Levis-Fitzgerald, Marc; Barber, Paul H.; Hasson, Tama

2015-01-01

The 6-yr degree-completion rate of undergraduate science, technology, engineering, and mathematics (STEM) majors at U.S. colleges and universities is less than 40%. Persistence among women and underrepresented minorities (URMs), including African-American, Latino/a, Native American, and Pacific Islander students, is even more troubling, as these students leave STEM majors at significantly higher rates than their non-URM peers. This study utilizes a matched comparison group design to examine the academic achievement and persistence of students enrolled in the Program for Excellence in Education and Research in the Sciences (PEERS), an academic support program at the University of California, Los Angeles, for first- and second-year science majors from underrepresented backgrounds. Results indicate that PEERS students, on average, earned higher grades in most “gatekeeper” chemistry and math courses, had a higher cumulative grade point average, completed more science courses, and persisted in a science major at significantly higher rates than the comparison group. With its holistic approach focused on academics, counseling, creating a supportive community, and exposure to research, the PEERS program serves as an excellent model for universities interested in and committed to improving persistence of underrepresented science majors and closing the achievement gap. PMID:25828403

Large Spatially Resolved Rectification in a Donor–Acceptor Molecular Heterojunction

DOE PAGES

Smerdon, Joseph A.; Giebink, Noel C.; Guisinger, Nathan P.; ...

2016-03-10

Here, we demonstrate that rectification ratios (RR) of ≳250 (≳1000) at biases of 0.5 V (1.2 V) are achievable at the two-molecule limit for donor–acceptor bilayers of pentacene on C 60 on Cu using scanning tunneling spectroscopy and microscopy. Using first-principles calculations, we show that the system behaves as a molecular Schottky diode with a tunneling transport mechanism from semiconducting pentacene to Cu- hybridized metallic C 60. Low-bias RRs vary by two orders-of-magnitude at the edge of these molecular heterojunctions due to increased Stark shifts and confinement effects.

Molecular microenvironments: Solvent interactions with nucleic acid bases and ions

NASA Technical Reports Server (NTRS)

Macelroy, R. D.; Pohorille, A.

1986-01-01

The possibility of reconstructing plausible sequences of events in prebiotic molecular evolution is limited by the lack of fossil remains. However, with hindsight, one goal of molecular evolution was obvious: the development of molecular systems that became constituents of living systems. By understanding the interactions among molecules that are likely to have been present in the prebiotic environment, and that could have served as components in protobiotic molecular systems, plausible evolutionary sequences can be suggested. When stable aggregations of molecules form, a net decrease in free energy is observed in the system. Such changes occur when solvent molecules interact among themselves, as well as when they interact with organic species. A significant decrease in free energy, in systems of solvent and organic molecules, is due to entropy changes in the solvent. Entropy-driven interactioins played a major role in the organization of prebiotic systems, and understanding the energetics of them is essential to understanding molecular evolution.

Charge Transport Processes in Molecular Junctions

NASA Astrophysics Data System (ADS)

Smith, Christopher Eugene

Molecular electronics (ME) has evolved into a rich area of exploration that combines the fields of chemistry, materials, electronic engineering and computational modeling to explore the physics behind electronic conduction at the molecular level. Through studying charge transport properties of single molecules and nanoscale molecular materials the field has gained the potential to bring about new avenues for the miniaturization of electrical components where quantum phenomena are utilized to achieve solid state molecular device functionality. Molecular junctions are platforms that enable these studies and consist of a single molecule or a small group of molecules directly connected to electrodes. The work presented in this thesis has built upon the current understanding of the mechanisms of charge transport in ordered junctions using self-assembled monolayer (SAM) molecular thin films. Donor and acceptor compounds were synthesized and incorporated into SAMs grown on metal substrates then the transport properties were measured with conducting probe atomic force microscopy (CP-AFM). In addition to experimentally measured current-voltage (I-V) curves, the transport properties were addressed computationally and modeled theoretically. The key objectives of this project were to 1) investigate the impact of molecular structure on hole and electron charge transport, 2) understand the nature of the charge carriers and their structure-transport properties through long (<4 nm) conjugated molecular wires, and 3) quantitatively extract interfacial properties characteristic to macroscopic junctions, such as energy level alignment and molecule-contact electronic coupling from experimental I-V curves. Here, we lay ground work for creating a more complete picture of charge transport in macroscopically ordered molecular junctions of controlled architecture, length and charge carrier. The polaronic nature of hopping transport has been predicted in long, conjugated molecular wires