Thematische Bibliographien / Screening mechanisms

Inhaltsverzeichnis

Zeitschriftenartikel
Dissertationen
Bücher
Buchteile
Konferenzberichte
Berichte der Organisationen

Auswahl der wissenschaftlichen Literatur zum Thema „Screening mechanisms“

Autor: Grafiati

Veröffentlicht am 23. November 2024

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an

Wählen Sie eine Art der Quelle aus:

Machen Sie sich mit den Listen der aktuellen Artikel, Bücher, Dissertationen, Berichten und anderer wissenschaftlichen Quellen zum Thema "Screening mechanisms" bekannt.

Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.

Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.

Zeitschriftenartikel zum Thema "Screening mechanisms"

Brenner, Michael P. „Screening mechanisms in sedimentation“. Physics of Fluids 11, Nr. 4 (April 1999): 754–72. http://dx.doi.org/10.1063/1.869948.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Harsha, Tumula Mani, Gangaraju Sai Moukthika, Dudipalli Siva Sai, Mannuru Naga Rajeswari Pravallika und Satish Anamalamudi. „Survey on Resume Screening Mechanisms“. International Journal of Computer Science and Engineering 9, Nr. 4 (25.04.2022): 14–22. http://dx.doi.org/10.14445/23488387/ijcse-v9i4p103.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Loveland Cook, Cynthia A., Letha Chadiha, Bruce Schmidt, James Holloway und Jerry L. Satterwhite. „High Social Risk Screening Mechanisms“. Social Work in Health Care 16, Nr. 4 (31.08.1992): 101–17. http://dx.doi.org/10.1300/j010v16n04_07.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Brax, Philippe. „Screening mechanisms in modified gravity“. Classical and Quantum Gravity 30, Nr. 21 (04.10.2013): 214005. http://dx.doi.org/10.1088/0264-9381/30/21/214005.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Gibbs, Patty. „Screening Mechanisms in BSW Programs“. Journal of Social Work Education 30, Nr. 1 (Januar 1994): 63–74. http://dx.doi.org/10.1080/10437797.1994.10672214.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Chawan, Vinaysingh. „Screening Agents in Belief Eliciting Mechanisms“. Theoretical Economics Letters 06, Nr. 04 (2016): 783–88. http://dx.doi.org/10.4236/tel.2016.64082.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Saloner, Garth. „Old Boy Networks as Screening Mechanisms“. Journal of Labor Economics 3, Nr. 3 (Juli 1985): 255–67. http://dx.doi.org/10.1086/298055.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Hong, Seungbum, Serge M. Nakhmanson und Dillon D. Fong. „Screening mechanisms at polar oxide heterointerfaces“. Reports on Progress in Physics 79, Nr. 7 (16.06.2016): 076501. http://dx.doi.org/10.1088/0034-4885/79/7/076501.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Takahashi, Koshi, Sho Nakamura, Kaname Watanabe, Masahiko Sakaguchi und Hiroto Narimatsu. „Availability of Financial and Medical Resources for Screening Providers and Its Impact on Cancer Screening Uptake and Intervention Programs“. International Journal of Environmental Research and Public Health 19, Nr. 18 (12.09.2022): 11477. http://dx.doi.org/10.3390/ijerph191811477.

Der volle Inhalt der Quelle

Annotation:

Interventions for residents and medical/financial resources available to screening providers can improve cancer screening rates. Yet the mechanisms by which the interactions of these factors affect the screening rates remain unknown. This study employed structural equation modeling to analyze the mechanisms underlying these factors. Data for Japanese municipalities’ medical/financial status, their implementation of screening interventions, and the number of municipality-based cancer screening appointments from April 2016 to March 2017 were obtained from an open database. Five cancer screenings were included: gastric, lung, colorectal, breast, and cervical cancer screening; all are nationally recommended for population screening in Japan. We defined two latent variables, namely, intervention for residents and medical/financial resources, and then analyzed the relationships between these variables and screening rates using structural equation modeling. Models were constructed for gastric, lung, and breast cancer screening, and similar relationships were observed. With these cancer types, medical/financial resources affected the intervention for residents, directly affecting screening rates. One limitation of this study is that it only included screening by municipalities, which may cause selection bias. In conclusion, financial pressures and lack of medical resources may cause a reduction in screening intervention programs, leading to stagnant screening rates. Ensuring consistent implementation of interventions for residents may improve local and regional cancer screening rates.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Waye, Jerome D., Lars Aabakken, J. R. Armengol-Miro, Pedro Llorens, Christopher B. Williams und Qi-Lian Zhang. „Screening for GI cancer and payment mechanisms“. Gastrointestinal Endoscopy 55, Nr. 3 (März 2002): 453–54. http://dx.doi.org/10.1067/mge.2002.120319.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Mehr Quellen

Dissertationen zum Thema "Screening mechanisms"

Ruiz, Carmona Sergio. „Virtual screening for novel mechanisms of action: applications and methodological developments“. Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/400297.

Der volle Inhalt der Quelle

Annotation:

The main motivation of this thesis has been to validate, improve and develop new methods with respect to the ones available nowadays in the area of drug discovery, in order to be able to study more challenging targets in the near future that currently are out of our reach. As the productivity of the pharmaceutical industry is decreasing year after year over the last decades, the improvement of such methods would be a step forward. As we are mostly a computational lab, this thesis has focused on different computational approaches such as docking, molecular dynamics or chemoinformatics. On the first part of the thesis (first author on the publication in PLoS Computational Biology in 2014), I worked on Docking-based Virtual Screening (VS). Particularly, in validating rDock, a little-known but very powerful program that was published and released during this thesis as open source software. In order to validate it, we performed several benchmarking experiments with DUD and ASTEX sets to compare the performance of rDock against Glide and AutoDock Vina, two commonly used docking programs. The capabilities of rDock with respect to binding mode prediction (predict how a ligand structure will be upon binding to its receptor) and virtual screening (selecting the most likely active ligands amongst thousands or millions of drug-like molecules) were compared with Glide and Vina, and we demonstrated that rDock performed as well as them. On the second project of the thesis (first author on the publication in Nature Chemistry in 2016), we wanted to develop a novel computational tool for drug discovery not only that was complementary to the existing ones, but also that improved them by adding new ways of interpreting the data. Taking advantage of the already known technique of Steered Molecular Dynamics (SMD), we proposed an approach consisting in reducing the size of the system, focusing around a key interaction point and running SMD to discriminate between active and inactive ligands. This approach, or as we call it: "Dynamic Undocking", is intended to foster drug design efforts in the lead optimization stage by improving the efficiency of the in silico assessment of protein-ligand binding affinity. After a positive retrospective assessment of the method using different systems of the DUD set, a prospective validation was required to evaluate its feasibility in a real drug discovery project. Hsp90 was selected as the test system: A fragment library was created and a subset of fragments was selected for a first stage of docking-based VS. About 300.000 ligands were docked with rDock and the top-scoring ones were subjected to Dynamic Undocking. In a collaboration with Vernalis, a pharmaceutical company in the UK, we tested tens of compounds selected with Dynamic Undocking and we were able not only to find positive and novel hits but also to improve hit-rate with respect to standard fragment screening by almost 10 fold. Finally, we had the opportunity to participate in the D3R Grand Challenge 2015 where we could apply all the methods from this thesis (first author on the publication in Journal of Computer-Aided Molecular Design in 2016). This challenge was designed as a blind public test where different groups around the world tried to predict the binding mode and the affinity of a set of ligands for their respective protein target. Our approach consisted in a combination of docking and Dynamic Undocking and our results were placed amongst the best for the two systems of the challenge. We also discussed how the level of available data and previous knowledge on each of the systems impacted on the final results.
La motivación principal de esta tesis ha sido validar, mejorar y desarrollar nuevos métodos con relación a los disponibles hoy en día en el área del desarrollo de fármacos, para en un futuro poder estudiar dianas que actualmente están fuera de nuestro alcance. Debido a que la productividad de la industria farmacéutica está disminuyendo durante los últimos años, una mejora en los métodos disponibles sería un gran paso adelante. Esta tesis se ha centrado en diferentes métodos computacionales, como el docking o la dinámica molecular. En la primera de las partes, trabajé en el cribado virtual (Virtual Screening) basado en docking. Concretamente, participé en la validación del programa de docking rDock mediante la comparación con dos programas muy usados hoy en día de su capacidad de predecir correctamente el modo de unión de un ligando con su proteína diana y de sus resultados en el cribado virtual de posibles fármacos. En la segunda parte de la tesis, participé en el desarrollo de un método computacional novedoso en el diseño de fármacos que complementase y mejorase los métodos actualmente disponibles. Éste método, bautizado en inglés como “Dynamic Undocking”, consiste en una implementación específica de dinámica molecular mediante la cual somos capaces de detectar si un ligando puede ser activo o inactivo de manera rápida y eficiente. Se validó el método de manera retrospectiva y posteriormente se aplicó en otro proyecto con el objetivo de encontrar nuevos posibles fármacos para una proteína relacionada con cáncer. Gracias a una colaboración con una empresa del Reino Unido, encontramos nuevos ligandos de manera que aumentamos la tasa de éxito con relación a un método estándar en casi 10 veces. Por último, participé en el “D3R Grand Challenge 2015”, un experimento a escala mundial donde los participantes aplicaron diferentes métodos y compararon sus resultados respecto a dos métricas distintas: la predicción del modo de unión y la capacidad de ordenar los ligandos proporcionados por la organización por su afinidad respecto a la proteína diana. En nuestro caso, aplicamos una combinación de docking y “Dynamic Undocking” con unos resultados excelentes.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Jaworek, Karolina. „Screening for novel brain tumour initiation mechanisms at single cell resolution“. Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/screening-for-novel-brain-tumour-initiation-mechanisms-at-single-cell-resolution(3bb44859-bc78-4fce-a7df-0f47d2dd6b4e).html.

Der volle Inhalt der Quelle

Annotation:

Despite progress in our understanding of origin and development of brain tumours, more efficient therapeutic approaches addressing the high recurrence rate and poor prognosis of brain tumours remain urgently needed, in particular for the most aggressive glioblastomas (GBMs). In this work, I used the Drosophila brain tumour (brat) mutant as an in vivo model to identify potential mechanisms of brain tumour initiation. The human brat orthologue, Trim3, has a conserved tumour suppressor function in GBMs. I applied a single cell transcriptome microarray technique to compare intermediate neural progenitor cells harvested from live brat versus control larval brains, at a developmental stage when the first signs of molecular transformation into tumour initiation cells are observed in the mutants but no over-proliferation can yet be detected. I identified 1132 transcripts differentially expressed (threshold: -0.5Log2FC0.5). My gene ontology-based analysis revealed that metabolic pathways, RNA processing and protein synthesis are among the most represented functional categories. I validated the screen data via qPCRs, and translated gene expression findings into human GBM tissues and cell lines. I found 21 out of 24 human orthologue transcripts tested to be also differentially expressed in GBMs compared to control human brain tissues, suggesting the possibility of conserved roles. Finally, I examined in more detail selected individual transcripts. Of note, I showed that loss of two candidates found upregulated in brain tumour initiation cells and in GBMs, mob3 and l(2)k09022, causes severe impairment of normal postembryonic neural stem cell proliferation. I also demonstrated that another candidate, YME1L1, which contributes to mitochondrial proteostasis and respiration, is up regulated in tumour initiation cells and in GBMs at both mRNA and protein levels, suggesting it may promote tumour initiation by altering mitochondria function. In summary, the work I developed lays an original foundation for future studies of brain tumour initiation mechanisms.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Wang, An Qi. „Screening of hepatoprotective constituents from herbal medicines and investigation on the underlying mechanisms“. Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3690819.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Ibaraki, Alicia. „Mechanisms that perpetuate health disparities: physician stereotypes & bias“. Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23088.

Der volle Inhalt der Quelle

Annotation:

Purpose: Although Asian Americans are the only racial group for whom cancer is the leading cause of death, colorectal cancer screening is consistently lower than that of White Americans. Physicians also recommend colorectal cancer screening to Asian Americans at nearly half the rate as White Americans. This study tests a mechanism that may underlie low recommendation rates. I based my hypothesis on a conceptual model that integrates the literature on information processing and decision making with Asian American stereotypes. Methods: I conducted an online study of primary care physicians and measured their cancer screening referral behavior in response to clinical vignettes. I used the existing Asian Attitude Implicit Association Test (IAT) and developed a new Health Attitude IAT to measure implicit attitudes about Asian American foreignness and health advantages, respectively. Explicit attitudes about these constructs were also assessed through self-report. I used binary logistic regression models to evaluate the association of attitudes about Asian Americans foreignness and health advantage with screening recommendation. Results: My sample included 167 physicians (23% response rate). I found strong implicit bias that Asians are foreign (Cohen’s d = 1.09) and strong implicit bias favoring a white health advantage (Cohen’s d = -0.86). There were weaker explicit biases that Asians are foreign (Cohen’s d = 0.62). Explicit beliefs about health advantage favored Asians (Cohen’s d = 0.73). Physician race, age and gender were significant moderators of bias score. .I found no evidence of a race based screening disparity and no association between implicit or explicit bias scores and making a cancer screening recommendation. Conclusions: Foreign and health advantage biases exist among a sample of physicians, but may not influence cancer screening recommendation behavior. Physicians demonstrated both implicitly and explicitly held attitudes that Asian Americans are perpetual foreigners. Physicians also reported explicit beliefs that Asian Americans have health advantages relative to other races. Implicitly, their attitudes indicated that White Americans are a healthier group. Further research should address whether race-based cancer screening disparities persist in real world settings, both in terms of screening completion, and physician recommendation. If disparities still exist, alternate explanatory mechanisms should be identified.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Thistlethwaite, Rebecca Janette. „Identification of genetic variation in heat stress, genotype screening for and mechanisms of tolerance in wheat“. Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17339.

Der volle Inhalt der Quelle

Annotation:

Increasing global climatic variability will most likely increase temperatures and reduce annual rainfall in many cropping regions in the coming years. Changes in seasonal conditions are likely to have a significant impact on all food crops including wheat. This thesis aims to (1) identify genetic diversity for high temperature tolerance in bread wheat by evaluating a large number of genotypes across years and sowing dates, (2) evaluate a subset of germplasm was using different screening methods for heat tolerance (in-field controlled environment chambers and glasshouses) and (3) compare different screening methods, Field experiments were conducted between 2012 and 2015 to identify superior genotypes with tolerance to high temperature from Australian and international wheat germplasm. Yield and yield components and phenological and physiological traits were assessed each season. Mean maximum temperature between heading and maturity demonstrated that for every 1 °C rise in mean maximum temperature, grain yield decreased by approximately 230kg/ha. A subset of twenty genotypes was maintained across all years and times of sowing to assess trait stability under heat stress. A significant genotype x environment interaction was observed for yield and yield components and the size of the interaction differed by trait. In-field controlled environment chambers were designed to implement a heat shock at anthesis on normally sown materials to assess the validity of late sowing as a method for heat tolerance screening. The heat shock applied at anthesis using chambers consistently reduced grain number more than TKW, largely due to negative impacts on pollen viability. A glasshouse experiment was conducted to impose a heat shock to the same subset of twenty genotypes. Plants were heated for three days at pollen formation (meiosis) and anthesis. Heat shock at meiosis had a greater impact on yield components than heat shock at anthesis. An ideotype for the warmer conditions in northwestern NSW was developed from the trait responses and relationships with productivity traits such as yield, kernel weight and screenings. Such an ideotype would be short-statured, maintain and prolong greenness at booting and anthesis, maintain and produce larger grain, extend the vegetative period and produce a 1:1 ratio of grain to biomass.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Niegowski, Damian. „Structural biology of integral membrane proteins from methods to molecular mechanisms /“. Doctoral thesis, Stockholm : Department of Biochemistry and Biophysics, Stockholm Univeristy, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-30069.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Tsipa, Anastasia Isavella. „Understanding the factors and mechanisms that influence colorectal cancer screening uptake among socially deprived and non-deprived populations“. Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/22226/.

Der volle Inhalt der Quelle

Annotation:

Colorectal cancer (CRC) is the second most common cause of cancer death in the UK. Since the introduction of the NHS Bowel Cancer Screening Programme CRC incidence and mortality rates have reduced, however, screening uptake in the overall population remains suboptimal and is disproportionately low among populations with low socioeconomic status (SES) and Black and Minority Ethnic populations. This thesis aimed to critically assess the available evidence of public health interventions to improve CRC screening and to examine the possible mechanisms of socioeconomic inequalities in CRC screening uptake within a UK setting. A systematic review and meta-analysis (Study 1) of randomised controlled trials (RCTs) to increase CRC screening uptake was conducted. Data from 102 RCTs including 1.94 million participants were analysed and intervention effectiveness was examined by level of SES. Interventions significantly improved screening uptake, especially among low SES populations, and helped reduce - but not eliminate - SES disparities. Specific intervention strategies were highlighted as effective among low SES groups. Study 2 used qualitative interviews (N = 27) to explore the views of different socioeconomic and sociodemographic population subgroups and identify the barriers and facilitators to CRC screening. Results highlighted both practical and emotional factors that influenced screening decisions and revealed both similarities and differences in the views of different subgroups. Study 3 used cross-sectional, observational, survey data (N = 206) to explore key sociodemographic and psychosocial variables as potential moderators and mediators of screening intention. Results indicated that psychosocial variables mediated the effects of past behaviour on screening intention and identified some differences by educational attainment and area-level deprivation. This thesis argues the importance of considering both sociodemographic and psychosocial factors in relation to improving CRC screening uptake and reducing inequalities. Results highlighted key determinants of CRC screening participation and identified specific pathways via which sociodemographic and psychosocial variables interact to affect screening intention. This thesis provides an evidentiary basis that can be used to inform future public health initiatives and/or interventions that aim to reduce the CRC inequality gap.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Piotrowska, Barbara. „Investigating the performance and underlying mechanisms of a novel screening measure for developmental dyslexia : implications for early identification“. Thesis, Edinburgh Napier University, 2018. http://researchrepository.napier.ac.uk/Output/1253563.

Der volle Inhalt der Quelle

Annotation:

Developmental dyslexia is a common disorder affecting around 10% of the British population characterized by difficulties with reading despite adequate intelligence and education (IDA, 2007). Although most researchers and practitioners would agree that early identification is key in limiting negative consequences of reading problems, this is still difficult to achieve due to theoretical and practical inconsistencies in the field. This thesis focuses on investigating a novel, computer and tablet-based “dot-to-dot” (DtD) task that may aid the process of identification particularly in pre-reading children and English as additional language (EAL) individuals who, by definition, are more susceptible to misidentification. Performance on this task was tested in primary school children (N = 457) and in adults (N = 111) together with a set of dyslexia-sensitive, vision and reasoning tests. Performance on DtD (especially the first sector error) demonstrated significant differences between children at high and low risk of dyslexia (as assessed by Lucid Rapid), as well as between children prospectively identified as poor and typical readers. DtD measures added small but statistically significant unique contributions to the models predicting reading scores and reading level group membership, and DtD measures could distinguish between poor and typical readers as well as between adults with and without diagnosed dyslexia. The findings provide evidence for the DtD test to be a useful addition to existing tests as it presumably relates to a number of mechanisms in line with automaticity and cerebellar deficits theories of dyslexia. It also has a potential to identify a distinct type of dyslexia that is not related to phonological processing which has important theoretical and practical implications.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Theodorou, Andria Soteri. „Screening and delineation of molecular mechanisms of action of HbF inducing agents for the treatment of β-thalassaemia“. Thesis, King's College London (University of London), 2015. http://kclpure.kcl.ac.uk/portal/en/theses/screening-and-delineation-of-molecular-mechanisms-of-action-of-hbf-inducing-agents-for-the-treatment-of-thalassaemia(fbad43de-f2b2-49a1-980b-b6dfcc1a25c5).html.

Der volle Inhalt der Quelle

Annotation:

Current agents used for pharmacological reactivation of foetal haemoglobin (HbF) have limited application due to moderate therapeutic properties, variable patient response and potential cytotoxic effects. Therefore, identification of novel HbF inducing agents is still a major research goal to this day. Identification of new potential HbF inducers has been mainly based on screening of drug libraries. However, this approach has not been very successful in generating new promising agents. In the current project, I employed two approaches for identifying potential HbF inducers: 1) screening of agents that are structurally similar to compounds with known HbF inducing activity; 2) investigating molecular pathways of a known HbF inducer with the aim of identifying suitable targets for therapeutic manipulation and target-based drug design. The first approach involved screening of eleven xanthines including caffeine and nine hydroxystilbenic derivatives of resveratrol as potential HbF inducers. However, none of the agents had a potent enough HbF inducing activity in order to be considered as promising therapeutic agents. In the second approach, decitabine was chosen based on its high HbF inducing activity and moderate cytotoxicity in K562 cells and primary human erythroid cultures. Chromatin immunoprecipitation was used to characterise epigenetic changes in the β-globin gene locus, and quantitative real-time PCR for investigation of changes in gene expression levels of ten erythroid-related genes, in the presence of the agent. A quantitative iTRAQ proteomic approach coupled with mass spectrometry was used for identification of changes in the proteome of decitabine-treated and un-treated primary human erythroid cultures. The findings suggest that decitabine induces HbF production through activation of signal transduction pathways rather than through hypomethylation of gene promoters. One such possible pathway is the NF-κB pathway. Among the differentially expressed proteins, twenty-seven proteins were associated with the action of decitabine. Two of those proteins, ARHGAP4 and EGLN2, were previously implicated in hydroxyurea-mediated induction of γ-globin gene expression and hypoxia-mediated erythropoiesis, respectively. In addition, the de-ubiquitinating enzyme USP11 was substantially modulated in the presence of decitabine. The exact role of these proteins in γ-globin expression remains to be established.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

White, Rose. „Cyclin dependent kinase like 5 (CDKL5) mutation screening in Rett Syndrome and related clinical disorders“. Thesis, The University of Sydney, 2007. https://hdl.handle.net/2123/28108.

Der volle Inhalt der Quelle

Annotation:

Rett Syndrome (RTT) is a severe neurodevelopmental disorder affecting almost exclusively females, with an incidence of 1 in 8,000 by 15 yrs of age. The disorder encompasses a wide spectrum of clinical phenotypes. Up to 95% of classical RTT and a lesser proportion (20%-60%) of those with atypical forms of RTT patients carry mutations in the X-linked MECP2 gene (Methyl-CpG binding protein 2), the first gene discovered to be associated with this disorder. Mutations in the X-Iinked CDKL5 gene (cyclin-dependent kinase-like 5) have also been found to cause atypical RTT (in particular, the early onset seizure variant), autism, X-Iinked infantile spasm syndrome (ISSX), intellectual disability and other severe neurological disorders. This study investigates the speculation that CDKL5 deficiency may underlie a significant proportion of RTT cases that were not linked to MECP2 mutations. It is also investigates the possibility that CDKL5 mutations may lead to other non-RTT syndrome neurological disorders. The clinical cohort consisted of MECP2 mutation-negative RTT patients (91), males with X-Iinked mental retardation (8), patients with ISSX (52), patients with autism (59) and other patients with intellectual disability with or without seizures (39). The 21 coding exons of CDKL5 were screened by Denaturing High Performance Liquid Chromatography and direct sequencing. In all, six polymorphic variations and one probably pathogenic mutation were identified, accounting for 46 of the 249 patients in this cohort (17%). Each individual identified with a variation had the clinical feature of seizures. Based on other studies, it appears that the key feature that points to a CDKL5 mutation will be the presence of severe early onset seizures, particularly infantile spasms. The results of mutation screening in this cohort lead us to conclude that pathogenic CDKL5 mutations are unlikely to be identified in neurological disorders unless a RTT-like phenotype with severe early-onset seizures are present.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Mehr Quellen

Bücher zum Thema "Screening mechanisms"

service), SpringerLink (Online, Hrsg. Photoprotection in Plants: Optical Screening-based Mechanisms. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2010.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

M, Hardy Leslie, und Institute of Medicine (U.S.). Committee on Prenatal and Newborn Screening for HIV Infection., Hrsg. HIV screening of pregnant women and newborns. Washington, D.C: National Academy Press, 1991.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

O, St Louis Kenneth. Oral speech mechanism screening examination: Examiner's manual. 3. Aufl. Austin, Tex: Pro-ed, 2000.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Tafazoli, Shahrzad. Accelerated cytotoxic mechanism screening (ACMS) of radical hepatotoxins. Ottawa: National Library of Canada, 2002.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Piazza, Gianmatteo. A screening mechanism in an efficiency wage model with adverse selection. [s.l.]: typescript, 1993.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

EricksonKirk, M. T. Recommended screening limits for pressurized thermal shock (PTS). Washington, DC: United States Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, 2010.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Papadopoulos, Demetrios S. Use of unbalanced laminates as a screening method for microcracking. [Washington, D.C.]: NASA, 1990.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Klaus, Leonore. Untersuchungen zum Mechanismus der Kohlenstoff-Katabolit-Inaktivierung in Hefen: Entwicklung eines Screening-Systems zur Isolierung von Inaktivierungs-Mutanten und deren Charakterisierung. [s.l.]: [s.n.], 1985.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Patlak, Margie. Mammography and beyond: Developing technologies for the early detection of breast cancer : a non-technical summary. Herausgegeben von National Cancer Policy Board (U.S.). Committee on the Early Detection of Breast Cancer und National Research Council (U.S.). Commission on Life Sciences. Washington, D.C: National Academy Press, 2001.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Solovchenko, Alexei. Photoprotection in Plants: Optical Screening-based Mechanisms. Springer, 2011.

Den vollen Inhalt der Quelle finden

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Mehr Quellen

Buchteile zum Thema "Screening mechanisms"

Brax, Philippe. „Screening Mechanisms“. In Modified Gravity and Cosmology, 293–98. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-83715-0_20.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Fox, B. W. „Mechanisms of Drug Resistance in Screening“. In Human Tumour Xenografts in Anticancer Drug Development, 123–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-73252-2_22.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Zhang, Fan, Meijuan Yin, Shichang Ding und Fenlin Liu. „Landmarks Screening Method Based on Elliptical Trajectories Constraint“. In Mechanisms and Machine Science, 469–76. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-68775-4_37.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dimitropoulos, Georgios. „National Security: The Role of Investment Screening Mechanisms“. In Handbook of International Investment Law and Policy, 1–37. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-13-5744-2_59-1.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dimitropoulos, Georgios. „National Security: The Role of Investment Screening Mechanisms“. In Handbook of International Investment Law and Policy, 507–43. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-13-3615-7_59.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Franklin, Linda A., und Klaus Lüning. „Natural UV Enhances Chloroplast Protein Damage in Chondrus Crispus, Despite the Presence of UV Screening Pigments“. In Photosynthesis: Mechanisms and Effects, 2357–59. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-3953-3_553.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Taunk, Jyoti, Chandan Kumar Singh, Deepti Singh, Ram Sewak Singh Tomar, Dharmendra Singh und Madan Pal. „Aluminum Toxicity Tolerance in Food Legumes: Mechanisms, Screening, and Inheritance“. In Legumes: Physiology and Molecular Biology of Abiotic Stress Tolerance, 369–90. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-5817-5_15.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Shikanai, T., K. Shimizu, T. Endo und T. Hashimoto. „Screening of Arabidopsis Mutants Lacking Down-Regulation of Photosystem II Using an Imaging System of Chlorophyll Fluorescence“. In Photosynthesis: Mechanisms and Effects, 4293–96. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-3953-3_992.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Mészáros, Ilona, Gyula Lakatos, Szilvia Veres, Anikó Papp und Imre Lánszki. „Screening Glyphosate-Induced Changes in the Photosynthesis of Duckweed Lemna Gibba L. by Using Chlorophyll Fluorescence Induction Method“. In Photosynthesis: Mechanisms and Effects, 4073–76. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-3953-3_945.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Nath, Krishna, James P. O’Donnell und Yan Lu. „Chlorophyll Fluorescence for High-Throughput Screening of Plants During Abiotic Stress, Aging, and Genetic Perturbation“. In Photosynthesis: Structures, Mechanisms, and Applications, 261–73. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-48873-8_12.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Konferenzberichte zum Thema "Screening mechanisms"

Xie, Yun, Yucheng Wu, Hongyan Wang und Ang Li. „A Trusted Mechanism for Participant Screening and Verification in Federated Learning“. In 2024 4th International Conference on Machine Learning and Intelligent Systems Engineering (MLISE), 446–49. IEEE, 2024. http://dx.doi.org/10.1109/mlise62164.2024.10673891.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Cheng, T. K., M. S. Dresselhaus und E. P. Ippen. „Direct observation of ultrafast ionic screening“. In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/up.1994.tua.1.

Der volle Inhalt der Quelle

Annotation:

Recently, it has been shown that coherent optical phonons can be excited in semimetals[1,2], semiconductors[2-4] and superconductors[5]. In all cases, pulses of laser light, which are short compared to the optical phonon period, are used to impulsively generate the coherent lattice vibrations. While the experimental methods for phonon excitation are similar, the physical mechanisms responsible for phonon generation appear to differ among the various materials types. For semimetals and narrow-gap semiconductors, the reflectivity modulation observed with the pump-probe technique have been particularly large (on the order of 10% in some materials) and have suggested significant modulation of the material's electronic structure. In these cases, we have determined that the coherent phonon excitation is caused by a mechanism we call Displacive Excitation of Coherent Phonons (DECP) [2,6].

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Minssieux, L. „Removal of Asphalt Deposits by Cosolvent Squeeze: Mechanisms and Screening“. In SPE Formation Damage Control Conference. Society of Petroleum Engineers, 1998. http://dx.doi.org/10.2118/39447-ms.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Kato, Yasuo. „Non-linear screening effects in nuclear reactions in matter“. In FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier. AIP, 2006. http://dx.doi.org/10.1063/1.2338417.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Zhou, Wenrong, Tianyu Song, Min Long, Jiye Liu, Qunsheng Ji und Yong Cang. „Abstract 2088: Comprehensive CRISPR screening unravel the different mechanisms of IMiDs resistance“. In Proceedings: AACR Annual Meeting 2019; March 29-April 3, 2019; Atlanta, GA. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/1538-7445.sabcs18-2088.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dascaliuc, Alexandru. „Hormesis, screening and practical use of biostimulators in agriculture“. In International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.44.

Der volle Inhalt der Quelle

Annotation:

The term hormesis describes the biphasic response of any biological system to increasing the dose of the stress factor of a different nature, characterized in that low doses have stimulating, beneficial effects. In contrast, high doses cause harmful, inhibitory effects. The hormonal response is practically universal, being stimulated by the action of toxic substances, heavy metal ions, hormones, including physical factors. The standard type of response to different factors suggests installing these evolving mechanisms, so they are of particular interest in elucidating plant adaptation mechanisms to various stressors, including developing screening methods and practical use of biostimulators. The practical use of hormesis principles was the theoretical basis for elaboration and rational use of the biostimulator Reglalg in agriculture.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Marcireau, Christophe, Karine Berthelot, Alice Williart, Hamida Fournet, Delphine Debono, Gilbert Thill, Helene Erasimus et al. „Abstract 1272: Whole genome Crispr screening to identify potential SERD molecule resistance mechanisms“. In Proceedings: AACR Annual Meeting 2019; March 29-April 3, 2019; Atlanta, GA. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/1538-7445.sabcs18-1272.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Suleimanov, B. A., F. S. Ismailov, O. A. Dyshin und E. F. Veliyev. „Screening Evaluation of EOR Methods Based on Fuzzy Logic and Bayesian Inference Mechanisms“. In SPE Russian Petroleum Technology Conference and Exhibition. Society of Petroleum Engineers, 2016. http://dx.doi.org/10.2118/182044-ms.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Berichte der Organisationen zum Thema "Screening mechanisms"

Gutman, Éva. FDI screening regime of the European Union, is a way toward protectionism? ELTE Faculty of Law, 2024. http://dx.doi.org/10.58360/20240607-gutman.

Der volle Inhalt der Quelle

Annotation:

Foreign direct investment is undeniably one of the drivers of economic development, and as such, it has economic benefits, and functions as a catalysator for international trade and globalization. Even though its positive returns, might be reasons to be restricted, especially when the planned FDI transaction conflicts with the public order or security interest of a State. To 2017, several trading partners of the European Union already established FDI screening mechanisms or restrictive measures, what caused inequality toward the Union. Furthermore, more Member States had already introduced FDI screening rules, what caused regulatory discrepancies amongst the Member States. Therefore, although the European Union is still amongst the most open economies on earth, the creation of an FDI due diligence framework was necessary. In regard of three years after its fully applicability, the Regulation, and the operation of the FDI screening mechanisms of the Member States are worth to be reviewed. Moreover, the first FDIrelated case law is emerged, where different interpretation of conceptual definitions is visible, yet the judgement of ECJ follows the previous ones. As a conclusion, the FDI screening Regulation has accomplished its two-sided goal. Firstly, it is not an unprecedented protectionism, but rather a reactive step towards third countries and secondly, it harmonizes the FDI-framework with laying down minimum rules for Member States. In addition, it fits into the framework of other EU legal instruments, such as the European Merger Regulation or the Foreign Subsidies Regulation.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Bima, Luhur, Arjuni Rahmi Barasa, Shintia Revina, Niken Rarasati und Asri Yusrina. Screening Teachers in Indonesia: Does Ex-Ante Teacher Characteristics Assessment Predict Teaching Effectiveness? Research on Improving Systems of Education (RISE), März 2023. http://dx.doi.org/10.35489/bsg-rise-wp_2023/134.

Der volle Inhalt der Quelle

Annotation:

Selecting good teachers is vital as it can lead to a pool of teachers who will continuously strive to improve their teaching quality. Therefore, strengthening the assessment tools for screening effective teachers at their point of entry into the profession is important to improving teaching quality. While abundant studies have been conducted on improving teacher screening strategies in developed countries, only few have examined the process in the contexts of developing countries. Our study aims to enrich the literature on improving teacher screening in developing countries by testing sixty-two teachers using a set of teacher assessment instruments that measure both cognitive and non-cognitive skills. We discovered a significant and positive correlation between teacher competence in numeracy and student numeracy achievement. Furthermore, assessing teaching practices using a lesson demonstration is positively associated with students’ achievement. However, we found a significant but negative relationship between teacher competence in literacy and student literacy outcomes. We also reported a similar pattern in the correlation between teachers’ portfolio assessments and students’ learning outcomes. The negative correlation in literacy measurements may be explained by the difficulties experienced by teachers in Indonesia in translating their knowledge into practice, as there are no specific subjects designated to Indonesian language and reading comprehension. From a policy perspective, the government and education institutions can strengthen their teacher recruitment mechanisms by adopting instruments that can predict teacher effectiveness. Furthermore, these screening instruments should be combined with ex-post assessment tools as those assessments will provide a comprehensive overview of teacher capabilities, not only in terms of prospective teacher characteristics but also in terms of their actual classroom teaching performance after a certain period of teaching practice.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Eyal, Yoram, und Sheila McCormick. Molecular Mechanisms of Pollen-Pistil Interactions in Interspecific Crossing Barriers in the Tomato Family. United States Department of Agriculture, Mai 2000. http://dx.doi.org/10.32747/2000.7573076.bard.

Der volle Inhalt der Quelle

Annotation:

During the evolutionary process of speciation in plants, naturally occurring barriers to reproduction have developed that affect the transfer of genes within and between related species. These barriers can occur at several different levels beginning with pollination-barriers and ending with hybrid-breakdown. The interaction between pollen and pistils presents one of the major barriers to intra- and inter-specific crosses and is the focus of this research project. Our long-term goal in this research proposal was defined to resolve questions on recognition and communication during pollen-pistil interactions in the extended tomato family. In this context, this work was initiated and planned to study the potential involvement of tomato pollen-specific receptor-like kinases (RLK's) in the interaction between pollen and pistils. By special permission from BARD the objectives of this research were extended to include studies on pollen-pistil interactions and pollination barriers in horticultural crops with an emphasis on citrus. Functional characterization of 2 pollen-specific RLK's from tomato was carried out. The data shows that both encode functional kinases that were active as recombinant proteins. One of the kinases was shown to accumulate mainly after pollen germination and to be phosphorylated in-vitro in pollen membranes as well as in-vivo. The presence of style extract resulted in dephosphorylation of the RLK, although no species specificity was observed. This data implies a role for at least one RLK in pollination events following pollen germination. However, a transgenic plant analysis of the RLK's comprising overexpression, dominant-negative and anti-sense constructs failed to provide answers on their role in pollination. While genetic effects on some of the plants were observed in both the Israeli and American labs, no clear functional answers were obtained. An alternative approach to addressing function was pursued by screening for an artificial ligand for the receptor domain using a peptide phage display library. An enriched peptide sequence was obtained and will be used to design a peptide-ligand to be tested for its effect o pollen germination and tube growth. Self-incompatibility (SI) in citrus was studied on 3 varieties of pummelo. SI was observed using fluorescence microscopy in each of the 3 varieties and compatibility relations between varieties was determined. An initial screen for an S-RNase SI mechanism yielded only a cDNA homologous to the group of S-like RNases, suggesting that SI results from an as yet unknown mechanism. 2D gel electrophoresis was applied to compare pollen and style profiles of different compatibility groups. A "polymorphic" protein band from style extracts was observed, isolated and micro-sequenced. Degenerate primers designed based on the peptide sequence date will be used to isolate the relevant genes i order to study their potential involvement in SI. A study on SI in the apple cultivar Top red was initiated. SI was found, as previously shown, to be complete thus requiring a compatible pollinator variety. A new S-RNase allele was discovered fro Top red styles and was found to be highly homologous to pear S-RNases, suggesting that evolution of these genes pre-dated speciation into apples and pears but not to other Rosaceae species. The new allele provides molecular-genetic tools to determine potential pollinators for the variety Top red as well as a tool to break-down SI in this important variety.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Brockmann, Kolja, und Lauriane Héau. Developing Good Practices in Export Control Outreach to the NewSpace Industry. Stockholm International Peace Research Institute, März 2023. http://dx.doi.org/10.55163/bqao1685.

Der volle Inhalt der Quelle

Annotation:

NewSpace is changing the nature of the space industry, exacerbating missile proliferation risks and posing challenges for the effective implementation of export controls. NewSpace companies develop, test, produce, use and market missile-related emerging and dual-use technologies, including small and micro launchers. One of the measures states can take is to address these developments is to step up targeted outreach to NewSpace actors, raising awareness of such risks to strengthen compliance with export controls and foreign direct investment (FDI) screening mechanisms. Key elements of an effective outreach strategy for the NewSpace sector include tailored use of established outreach tools, mapping stakeholders, incentivizing participation in outreach activities, consistently engaging with launch vehicle manufacturers, inter-agency cooperation, and raising awareness of FDI-related risks. The Missile Technology Control Regime, the Hague Code of Conduct and the Wiesbaden Process provide multilateral forums through which states can begin sharing experiences and develop good practices for outreach to the NewSpace industry.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Avni, Adi, und Kirankumar S. Mysore. Functional Genomics Approach to Identify Signaling Components Involved in Defense Responses Induced by the Ethylene Inducing Xyalanase Elicitor. United States Department of Agriculture, Dezember 2009. http://dx.doi.org/10.32747/2009.7697100.bard.

Der volle Inhalt der Quelle

Annotation:

Plant-microbe interactions involve a large number of global regulatory systems, which are essential for plants to protect themselves against pathogen attack. An ethylene-inducing xylanase (EIX) of Trichoderma viride is a potent elicitor of plant defense responses, like hypersensitive response (HR), in specific cultivars of tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum). The central goal of this proposal was to investigate the molecular mechanisms that allow plants to specifically activate defense responses after EIX treatment. We proposed to identify cellular signaling components involved in the induction of HR by the EIX elicitor. The molecular genetic analysis of the signal transduction pathway that modulates hypersensitive responses is an important step in understanding the induction of plant defense responses. The genes that mediate LeEIX2-EIX dependent activation of resistance mechanisms remain to be identified. We used two approaches to identify the cellular signaling components that induce HR mediated by the EIX elicitor. In the first approach, we performed a yeast two-hybrid screening using LeEix2 as bait to identify plant proteins that interact with it. In the second approach, we used virus-induced gene silencing (VIGS) for a high-throughput screen to identify genes that are required for the induction of LeEIX2-EIX mediated HR. VIGS will also be used for functional characterization of genes that will be identified during the yeast two-hybrid screen. This investigation will shed light on cellular processes and signaling components involved in induction of general plant defense against pathogens and will provide the basis for future biotechnological approaches to improve plant resistance to pathogens. Several genes were indentified by the two approaches. We used the VIGS and yeast two hybrid approaches to confirm that activity of the genes initially identified by different procedure. Two genes inhibit the induction of HR by the fungal elicitor in the different systems; Tobacco-Harpin binding protein 1 and cyclopropyl isomerase.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Altstein, Miriam, und Ronald Nachman. Rationally designed insect neuropeptide agonists and antagonists: application for the characterization of the pyrokinin/Pban mechanisms of action in insects. United States Department of Agriculture, Oktober 2006. http://dx.doi.org/10.32747/2006.7587235.bard.

Der volle Inhalt der Quelle

Annotation:

The general objective of this BARD project focused on rationally designed insect neuropeptide (NP) agonists and antagonists, their application for the characterization of the mechanisms of action of the pyrokinin/PBAN (PK-PBAN) family and the development of biostable, bioavailable versions that can provide the basis for development of novel, environmentally-friendly pest insect control agents. The specific objectives of the study, as originally proposed, were to: (i) Test stimulatory potencies of rationally designed backbone cyclic (BBC) peptides on pheromonotropic, melanotropic, myotropic and pupariation activities; (ii) Test the inhibitory potencies of the BBC compounds on the above activities evoked either by synthetic peptides (PBAN, LPK, myotropin and pheromonotropin) or by the natural endogenous mechanism; (iii) Determine the bioavailability of the most potent BBC compounds that will be found in (ii); (iv) Design, synthesize and examine novel PK/PBAN analogs with enhanced bioavailability and receptor binding; (v) Design and synthesize ‘magic bullet’ analogs and examine their ability to selectively kill cells expressing the PK/PBAN receptor. To achieve these goals the agonistic and antagonistic activities/properties of rationally designed linear and BBC neuropeptide (NP) were thoroughly studied and the information obtained was further used for the design and synthesis of improved compounds toward the design of an insecticide prototype. The study revealed important information on the structure activity relationship (SAR) of agonistic/antagonistic peptides, including definitive identification of the orientation of the Pro residue as trans for agonist activity in 4 PK/PBANbioassays (pheromonotropic, pupariation, melanotropic, & hindgut contractile) and a PK-related CAP₂b bioassay (diuretic); indications that led to the identification of a novel scaffold to develop biostbiostable, bioavailable peptidomimetic PK/PBANagonists/antagonists. The work led to the development of an arsenal of PK/PBAN antagonists with a variety of selectivity profiles; whether between different PKbioassays, or within the same bioassay between different natural elicitors. Examples include selective and non-selective BBC and novel amphiphilic PK pheromonotropic and melanotropic antagonists some of which are capable of penetrating the moth cuticle in efficacious quantities. One of the latter analog group demonstrated unprecedented versatility in its ability to antagonize a broad spectrum of pheromonotropic elicitors. A novel, transPro mimetic motif was proposed & used to develop a strong, selective PK agonist of the melanotropic bioassay in moths. The first antagonist (pure) of PK-related CAP₂b diuresis in flies was developed using a cisPro mimetic motif; an indication that while a transPro orientation is associated with receptor agonism, a cisPro orientation is linked with an antagonist interaction. A novel, biostablePK analog, incorporating β-amino acids at key peptidase-susceptible sites, exhibited in vivo pheromonotropic activity that by far exceeded that of PBAN when applied topically. Direct analysis of neural tissue by state-of-the-art MALDI-TOF/TOF mass spectrometry was used to identify specific PK/PK-related peptides native to eight arthropod pest species [house (M. domestica), stable (S. calcitrans), horn (H. irritans) & flesh (N. bullata) flies; Southern cattle fever tick (B. microplus), European tick (I. ricinus), yellow fever mosquito (A. aegypti), & Southern Green Stink Bug (N. viridula)]; including the unprecedented identification of mass-identical Leu/Ile residues and the first identification of NPs from a tick or the CNS of Hemiptera. Evidence was obtained for the selection of Neb-PK-2 as the primary pupariation factor of the flesh fly (N. bullata) among native PK/PK-related candidates. The peptidomic techniques were also used to map the location of PK/PK-related NP in the nervous system of the model fly D. melanogaster. Knowledge of specific PK sequences can aid in the future design of species specific (or non-specific) NP agonists/antagonists. In addition, the study led to the first cloning of a PK/PBAN receptor from insect larvae (S. littoralis), providing the basis for SAR analysis for the future design of 2ⁿᵈgeneration selective and/or nonselective agonists/antagonists. Development of a microplate ligand binding assay using the PK/PBAN pheromone gland receptor was also carried out. The assay will enable screening, including high throughput, of various libraries (chemical, molecular & natural product) for the discovery of receptor specific agonists/antagonists. In summary, the body of work achieves several key milestones and brings us significantly closer to the development of novel, environmentally friendly pest insect management agents based on insect PK/PBANNPs capable of disrupting critical NP-regulated functions.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Cytryn, Eddie, Mark R. Liles und Omer Frenkel. Mining multidrug-resistant desert soil bacteria for biocontrol activity and biologically-active compounds. United States Department of Agriculture, Januar 2014. http://dx.doi.org/10.32747/2014.7598174.bard.

Der volle Inhalt der Quelle

Annotation:

Control of agro-associated pathogens is becoming increasingly difficult due to increased resistance and mounting restrictions on chemical pesticides and antibiotics. Likewise, in veterinary and human environments, there is increasing resistance of pathogens to currently available antibiotics requiring discovery of novel antibiotic compounds. These drawbacks necessitate discovery and application of microorganisms that can be used as biocontrol agents (BCAs) and the isolation of novel biologically-active compounds. This highly-synergistic one year project implemented an innovative pipeline aimed at detecting BCAs and associated biologically-active compounds, which included: (A) isolation of multidrug-resistant desert soil bacteria and root-associated bacteria from medicinal plants; (B) invitro screening of bacterial isolates against known plant, animal and human pathogens; (C) nextgeneration sequencing of isolates that displayed antagonistic activity against at least one of the model pathogens and (D) in-planta screening of promising BCAs in a model bean-Sclerotiumrolfsii system. The BCA genome data were examined for presence of: i) secondary metabolite encoding genes potentially linked to the anti-pathogenic activity of the isolates; and ii) rhizosphere competence-associated genes, associated with the capacity of microorganisms to successfully inhabit plant roots, and a prerequisite for the success of a soil amended BCA. Altogether, 56 phylogenetically-diverse isolates with bioactivity against bacterial, oomycete and fungal plant pathogens were identified. These strains were sent to Auburn University where bioassays against a panel of animal and human pathogens (including multi-drug resistant pathogenic strains such as A. baumannii 3806) were conducted. Nineteen isolates that showed substantial antagonistic activity against at least one of the screened pathogens were sequenced, assembled and subjected to bioinformatics analyses aimed at identifying secondary metabolite-encoding and rhizosphere competence-associated genes. The genome size of the bacteria ranged from 3.77 to 9.85 Mbp. All of the genomes were characterized by a plethora of secondary metabolite encoding genes including non-ribosomal peptide synthase, polyketidesynthases, lantipeptides, bacteriocins, terpenes and siderophores. While some of these genes were highly similar to documented genes, many were unique and therefore may encode for novel antagonistic compounds. Comparative genomic analysis of root-associated isolates with similar strains not isolated from root environments revealed genes encoding for several rhizospherecompetence- associated traits including urea utilization, chitin degradation, plant cell polymerdegradation, biofilm formation, mechanisms for iron, phosphorus and sulfur acquisition and antibiotic resistance. Our labs are currently writing a continuation of this feasibility study that proposes a unique pipeline for the detection of BCAs and biopesticides that can be used against phytopathogens. It will combine i) metabolomic screening of strains from our collection that contain unique secondary metabolite-encoding genes, in order to isolate novel antimicrobial compounds; ii) model plant-based experiments to assess the antagonistic capacities of selected BCAs toward selected phytopathogens; and iii) an innovative next-generation-sequencing based method to monitor the relative abundance and distribution of selected BCAs in field experiments in order to assess their persistence in natural agro-environments. We believe that this integrated approach will enable development of novel strains and compounds that can be used in large-scale operations.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Droby, Samir, Tim R. Gottwald, Richard Stange, Efraim Lewinsohn und T. Gregory McCollum. Characterization of the biochemical basis of host specificity of Penicillium digitatum and Penicillium italicum on citrus fruit. United States Department of Agriculture, Mai 2008. http://dx.doi.org/10.32747/2008.7587726.bard.

Der volle Inhalt der Quelle

Annotation:

l. This research demonstrates that citrus fruit volatiles play an important role in host recognition by P. digitatum and P. italicum. 2. Volatiles derived from non-host fruits and vegetables (apple, pear, tomato, pepper, strawberry and avocado) had no effect on promotion of spore germination and growth of citrus pathogens. 3. Citrus volatiles have a specific stimulatory effect solely on P. digitatum and P. italicum. Non-citrus pathogens such as P. expansum and B. cinerea not affected orinhibited by the volatile materials. The specific stimulatory effect of fruit peelvolatiles on citrus pathogens and inhibitory effect on non-pathogens indicateimport ant role of volatile compounds in the host selectivity of citrus postharvestpathogens. 4. Comparative CG-MS quantification was per formed and identification of volatileconstituents of citrus commercial oils, peel extracts and the headspace of thewounded fruits was completed. Monoterpenehydrocarbons (limonene, a-pinene,sabinene, and myrcene) were the most abundant in all volatiles regardless of thesource. 5. Our results demonstrated stimulation of germination and germ tube growth in both P. digitatum and P. italicum by limonene, myrcene, a-pinene, and b-pinene). Limonenewas show n to be the most efficient in induction of germination and growth in bothpathogens. 6. P. digitatum spores placed on the surface of lemon fruit, adjacent to a wounded oil gland, were induced to germinate and grow, thus supporting all the in vitro results and demonstrating that the phenomenon of stimulation of germination and growth occurs on the fruit. 7. We established that P. digitatum is capable of biotransformation of limonene to a terpineol. a-terpinel was proved to be involved in induction of fungal sporulation process. 8. Chemotropism (directional growth) of P. digitatum towards the volatiles released from the oil glands on fruit surface was demonstrated. 9. Citrus germplasm screening work for fruit susceptibility/resistance for P. digitatum infection showed no definitive results regarding host range and susceptibility.Although the sour orange selections appear to show higher resistance to infection and decay development. 10. We demonstrated that P. expansum, non citrus pathogen, is capable of germinating in citrus fruit surface wounds, but it strongly induced host resistance mechanisms which restrict it growth and prevented decay development. The host (citrus fruit) reacted strongly by production of ROS. On the other hand, P. digitatum seems to actively suppress host natural resistance mechanisms possibly through inhibiting the production of ROS production.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Shani, Uri, Lynn Dudley, Alon Ben-Gal, Menachem Moshelion und Yajun Wu. Root Conductance, Root-soil Interface Water Potential, Water and Ion Channel Function, and Tissue Expression Profile as Affected by Environmental Conditions. United States Department of Agriculture, Oktober 2007. http://dx.doi.org/10.32747/2007.7592119.bard.

Der volle Inhalt der Quelle

Annotation:

Constraints on water resources and the environment necessitate more efficient use of water. The key to efficient management is an understanding of the physical and physiological processes occurring in the soil-root hydraulic continuum.While both soil and plant leaf water potentials are well understood, modeled and measured, the root-soil interface where actual uptake processes occur has not been sufficiently studied. The water potential at the root-soil interface (yᵣₒₒₜ), determined by environmental conditions and by soil and plant hydraulic properties, serves as a boundary value in soil and plant uptake equations. In this work, we propose to 1) refine and implement a method for measuring yᵣₒₒₜ; 2) measure yᵣₒₒₜ, water uptake and root hydraulic conductivity for wild type tomato and Arabidopsis under varied q, K⁺, Na⁺ and Cl⁻ levels in the root zone; 3) verify the role of MIPs and ion channels response to q, K⁺ and Na⁺ levels in Arabidopsis and tomato; 4) study the relationships between yᵣₒₒₜ and root hydraulic conductivity for various crops representing important botanical and agricultural species, under conditions of varying soil types, water contents and salinity; and 5) integrate the above to water uptake term(s) to be implemented in models. We have made significant progress toward establishing the efficacy of the emittensiometer and on the molecular biology studies. We have added an additional method for measuring ψᵣₒₒₜ. High-frequency water application through the water source while the plant emerges and becomes established encourages roots to develop towards and into the water source itself. The yᵣₒₒₜ and yₛₒᵢₗ values reflected wetting and drying processes in the rhizosphere and in the bulk soil. Thus, yᵣₒₒₜ can be manipulated by changing irrigation level and frequency. An important and surprising finding resulting from the current research is the obtained yᵣₒₒₜ value. The yᵣₒₒₜ measured using the three different methods: emittensiometer, micro-tensiometer and MRI imaging in both sunflower, tomato and corn plants fell in the same range and were higher by one to three orders of magnitude from the values of -600 to -15,000 cm suggested in the literature. We have added additional information on the regulation of aquaporins and transporters at the transcript and protein levels, particularly under stress. Our preliminary results show that overexpression of one aquaporin gene in tomato dramatically increases its transpiration level (unpublished results). Based on this information, we started screening mutants for other aquaporin genes. During the feasibility testing year, we identified homozygous mutants for eight aquaporin genes, including six mutants for five of the PIP2 genes. Including the homozygous mutants directly available at the ABRC seed stock center, we now have mutants for 11 of the 19 aquaporin genes of interest. Currently, we are screening mutants for other aquaporin genes and ion transporter genes. Understanding plant water uptake under stress is essential for the further advancement of molecular plant stress tolerance work as well as for efficient use of water in agriculture. Virtually all of Israel’s agriculture and about 40% of US agriculture is made possible by irrigation. Both countries face increasing risk of water shortages as urban requirements grow. Both countries will have to find methods of protecting the soil resource while conserving water resources—goals that appear to be in direct conflict. The climate-plant-soil-water system is nonlinear with many feedback mechanisms. Conceptual plant uptake and growth models and mechanism-based computer-simulation models will be valuable tools in developing irrigation regimes and methods that maximize the efficiency of agricultural water. This proposal will contribute to the development of these models by providing critical information on water extraction by the plant that will result in improved predictions of both water requirements and crop yields. Plant water use and plant response to environmental conditions cannot possibly be understood by using the tools and language of a single scientific discipline. This proposal links the disciplines of soil physics and soil physical chemistry with plant physiology and molecular biology in order to correctly treat and understand the soil-plant interface in terms of integrated comprehension. Results from the project will contribute to a mechanistic understanding of the SPAC and will inspire continued multidisciplinary research.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Fahima, Tzion, und Jorge Dubcovsky. Map-based cloning of the novel stripe rust resistance gene YrG303 and its use to engineer 1B chromosome with multiple beneficial traits. United States Department of Agriculture, Januar 2013. http://dx.doi.org/10.32747/2013.7598147.bard.

Der volle Inhalt der Quelle

Annotation:

Research problem: Bread wheat (Triticumaestivum) provides approximately 20% of the calories and proteins consumed by humankind. As the world population continues to increase, it is necessary to improve wheat yields, increase grain quality, and minimize the losses produced by biotic and abiotic stresses. Stripe rust, caused by Pucciniastriiformisf. sp. tritici(Pst), is one of the most destructive diseases of wheat. The new pathogen races are more virulent and aggressive than previous ones and have produced large economic losses. A rich source for stripe-rust resistance genes (Yr) was found in wild emmer wheat populations from Israel. Original Project goals: Our long term goal is to identify, map, clone, characterize and deploy in breeding, novel wild emmer Yr genes, and combine them with multiple beneficial traits. The current study was aiming to map and clone YrG303 and Yr15, located on chromosome 1BS and combine them with drought resistance and grain quality genes. Positional cloning of YrG303/Yr15: Fine mapping of these genes revealed that YrG303 is actually allelic to Yr15. Fine genetic mapping using large segregating populations resulted in reduction of the genetic interval spanning Yr15 to less than 0.1 cM. Physical mapping of the YrG303/Yr15 locus was based on the complete chromosome 1BS physical map of wheat constructed by our group. Screening of 1BS BAC library with Yr15 markers revealed a long BAC scaffold covering the target region. The screening of T. dicoccoidesaccession-specific BAC library with Yr15 markers resulted in direct landing on the target site. Sequencing of T. dicoccoidesBAC clones that cover the YrG303/Yr15 locus revealed a single candidate gene (CG) with conserved domains that may indicate a role in disease resistance response. Validation of the CG was carried out using EMS mutagenesis (loss-of- function approach). Sequencing of the CG in susceptible yr15/yrG303 plants revealed three independent mutants that harbour non-functional yr15/yrG303 alleles within the CG conserved domains, and therefore validated its function as a Pstresistance gene. Evaluation of marker-assisted-selection (MAS) for Yr15. Introgressions of Yr15 into cultivated wheat are widely used now. Recently, we have shown that DNA markers linked to Yr15 can be used as efficient tools for introgression of Yr15 into cultivated wheat via MAS. The developed markers were consistent and polymorphic in all 34 tested introgressions and are the most recommended markers for the introgression of Yr15. These markers will facilitate simultaneous selection for multiple Yr genes and help to avoid escapees during the selection process. Engineering of improved chromosome 1BS that harbors multiple beneficial traits. We have implemented the knowledge and genetic resources accumulated in this project for the engineering of 1B "super-chromosome" that harbors multiple beneficial traits. We completed the generation of a chromosome including the rye 1RS distal segment associated with improved drought tolerance with the Yr gene, Yr15, and the strong gluten allele 7Bx-over-expressor (7Bxᴼᴱ). We have completed the introgression of this improved chromosome into our recently released variety Patwin-515HP and our rain fed variety Kern, as well as to our top breeding lines UC1767 and UC1745. Elucidating the mechanism of resistance exhibited by Yr36 (WKS1). The WHEAT KINASE START1 (WKS1) resistance gene (Yr36) confers partial resistance to Pst. We have shown that wheat plants transformed with WKS1 transcript are resistant to Pst. WKS1 is targeted to the chloroplast where it phosphorylates the thylakoid-associatedascorbateperoxidase (tAPX) and reduces its ability to detoxify peroxides. Based on these results, we propose that the phosphorylation of tAPX by WKS1 reduces the ability of the cells to detoxify ROS and contributes to cell death. Distribution and diversity of WKS in wild emmer populations. We have shown that WKS1 is present only in the southern distribution range of wild emmer in the Fertile Crescent. Sequence analysis revealed a high level of WKS1 conservation among wild emmer populations, in contrast to the high level of diversity observed in NB-LRR genes. This phenomenon shed some light on the evolution of genes that confer partial resistance to Pst. Three new WKS1 haplotypes displayed a resistance response, suggesting that they can be useful to improve wheat resistance to Pst. In summary, we have improved our understanding of cereals’ resistance mechanisms to rusts and we have used that knowledge to develop improved wheat varieties.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Wir bieten Rabatte auf alle Premium-Pläne für Autoren, deren Werke in thematische Literatursammlungen aufgenommen wurden. Kontaktieren Sie uns, um einen einzigartigen Promo-Code zu erhalten!