A Golgi-localized Hexose Transporter Is Involved in Heterotrimeric G Protein-mediated Early Development in Arabidopsis

Signal transduction involving heterotrimeric G proteins is universal among fungi, animals, and plants. In plants and fungi, the best understood function for the G protein complex is its modulation of cell proliferation and one of several important signals that are known to modulate the rate at which these cells proliferate is d-glucose. Arabidopsis thaliana seedlings lacking the β subunit (AGB1) of the G protein complex have altered cell division in the hypocotyl and are d-glucose hypersensitive. With the aim to discover new elements in G protein signaling, we screened for gain-of-function suppressors of altered cell proliferation during early development in the agb1-2 mutant background. One agb1-2-dependent suppressor, designated sgb1-1D for suppressor of G protein beta1 (agb1-2), restored to wild type the altered cell division in the hypocotyl and sugar hypersensitivity of the agb1-2 mutant. Consistent with AGB1 localization, SGB1 is found at the highest steady-state level in tissues with active cell division, and this level increases in hypocotyls when grown on d-glucose and sucrose. SGB1 is shown here to be a Golgi-localized hexose transporter and acts genetically with AGB1 in early seedling development

Tool wear monitoring using neuro-fuzzy techniques: a comparative study in a turning process

Tool wear detection is a key issue for tool condition monitoring. The maximization of useful tool life is frequently related with the optimization of machining processes. This paper presents two model-based approaches for tool wear monitoring on the basis of neuro-fuzzy techniques. The use of a neuro-fuzzy hybridization to design a tool wear monitoring system is aiming at exploiting the synergy of neural networks and fuzzy logic, by combining human reasoning with learning and connectionist structure. The turning process that is a well-known machining process is selected for this case study. A four-input (i.e., time, cutting forces, vibrations and acoustic emissions signals) single-output (tool wear rate) model is designed and implemented on the basis of three neuro-fuzzy approaches (inductive, transductive and evolving neuro-fuzzy systems). The tool wear model is then used for monitoring the turning process. The comparative study demonstrates that the transductive neuro-fuzzy model provides better error-based performance indices for detecting tool wear than the inductive neuro-fuzzy model and than the evolving neuro-fuzzy model

Imipenem resistance of Pseudomonas in pneumonia: a systematic literature review

<p>Abstract</p> <p>Background</p> <p>Pneumonia, and particularly nosocomial (NP) and ventilator-associated pneumonias (VAP), results in high morbidity and costs. NPs in particular are likely to be caused by <it>Pseudomonas aeruginosa </it>(PA), ~20% of which in observational studies are resistant to imipenem. We sought to identify the burden of PA imipenem resistance in pneumonia.</p> <p>Methods</p> <p>We conducted a systematic literature review of randomized controlled trials (RCT) of imipenem treatment for pneumonia published in English between 1993 and 2008. We extracted study, population and treatment characteristics, and proportions caused by PA. Endpoints of interest were: PA resistance to initial antimicrobial treatment, clinical success, microbiologic eradication and on-treatment emergence of resistance of PA.</p> <p>Results</p> <p>Of the 46 studies identified, 20 (N = 4,310) included patients with pneumonia (imipenem 1,667, PA 251; comparator 1,661, PA 270). Seven were double blind, and 7 included US data. Comparator arms included a β-lactam (17, [penicillin 6, carbapenem 4, cephalosporin 7, monobactam 1]), aminoglycoside 2, vancomycin 1, and a fluoroquinolone 5; 5 employed double coverage. Thirteen focused exclusively on pneumonia and 7 included pneumonia and other diagnoses. Initial resistance was present in 14.6% (range 4.2-24.0%) of PA isolates in imipenem and 2.5% (range 0.0-7.4%) in comparator groups. Pooled clinical success rates for PA were 45.2% (range 0.0-72.0%) for imipenem and 74.9% (range 0.0-100.0%) for comparator regimens. Microbiologic eradication was achieved in 47.6% (range 0.0%-100.0%) of isolates in the imipenem and 52.8% (range 0.0%-100.0%) in the comparator groups. Resistance emerged in 38.7% (range 5.6-77.8%) PA isolates in imipenem and 21.9% (range 4.8-56.5%) in comparator groups.</p> <p>Conclusions</p> <p>In the 15 years of RCTs of imipenem for pneumonia, PA imipenem resistance rates are high, and PA clinical success and microbiologic eradication rates are directionally lower for imipenem than for comparators. Conversely, initial and treatment-emergent resistance is more likely with the imipenem than the comparator regimens.</p

Aspartoacylase-LacZ Knockin Mice: An Engineered Model of Canavan Disease

Canavan Disease (CD) is a recessive leukodystrophy caused by loss of function mutations in the gene encoding aspartoacylase (ASPA), an oligodendrocyte-enriched enzyme that hydrolyses N-acetylaspartate (NAA) to acetate and aspartate. The neurological phenotypes of different rodent models of CD vary considerably. Here we report on a novel targeted aspa mouse mutant expressing the bacterial β-Galactosidase (lacZ) gene under the control of the aspa regulatory elements. X-Gal staining in known ASPA expression domains confirms the integrity of the modified locus in heterozygous aspa lacZ-knockin (aspalacZ/+) mice. In addition, abundant ASPA expression was detected in Schwann cells. Homozygous (aspalacZ/lacZ) mutants are ASPA-deficient, show CD-like histopathology and moderate neurological impairment with behavioural deficits that are more pronounced in aspalacZ/lacZ males than females. Non-invasive ultrahigh field proton magnetic resonance spectroscopy revealed increased levels of NAA, myo-inositol and taurine in the aspalacZ/lacZ brain. Spongy degeneration was prominent in hippocampus, thalamus, brain stem, and cerebellum, whereas white matter of optic nerve and corpus callosum was spared. Intracellular vacuolisation in astrocytes coincides with axonal swellings in cerebellum and brain stem of aspalacZ/lacZ mutants indicating that astroglia may act as an osmolyte buffer in the aspa-deficient CNS. In summary, the aspalacZ mouse is an accurate model of CD and an important tool to identify novel aspects of its complex pathology

User-centered virtual environment design for virtual rehabilitation

<p>Abstract</p> <p>Background</p> <p>As physical and cognitive rehabilitation protocols utilizing virtual environments transition from single applications to comprehensive rehabilitation programs there is a need for a new design cycle methodology. Current human-computer interaction designs focus on usability without benchmarking technology within a user-in-the-loop design cycle. The field of virtual rehabilitation is unique in that determining the efficacy of this genre of computer-aided therapies requires prior knowledge of technology issues that may confound patient outcome measures. Benchmarking the technology (e.g., displays or data gloves) using healthy controls may provide a means of characterizing the "normal" performance range of the virtual rehabilitation system. This standard not only allows therapists to select appropriate technology for use with their patient populations, it also allows them to account for technology limitations when assessing treatment efficacy.</p> <p>Methods</p> <p>An overview of the proposed user-centered design cycle is given. Comparisons of two optical see-through head-worn displays provide an example of benchmarking techniques. Benchmarks were obtained using a novel vision test capable of measuring a user's stereoacuity while wearing different types of head-worn displays. Results from healthy participants who performed both virtual and real-world versions of the stereoacuity test are discussed with respect to virtual rehabilitation design.</p> <p>Results</p> <p>The user-centered design cycle argues for benchmarking to precede virtual environment construction, especially for therapeutic applications. Results from real-world testing illustrate the general limitations in stereoacuity attained when viewing content using a head-worn display. Further, the stereoacuity vision benchmark test highlights differences in user performance when utilizing a similar style of head-worn display. These results support the need for including benchmarks as a means of better understanding user outcomes, especially for patient populations.</p> <p>Conclusions</p> <p>The stereoacuity testing confirms that without benchmarking in the design cycle poor user performance could be misconstrued as resulting from the participant's injury state. Thus, a user-centered design cycle that includes benchmarking for the different sensory modalities is recommended for accurate interpretation of the efficacy of the virtual environment based rehabilitation programs.</p

MRI of the kidney—state of the art

Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted

Promoting Pre-Service Teachers' Ideas About Nature of Science Through Educational Research Apprenticeship

Scopu

Investigating students' interest in chemistry through self-generated questions

This study investigates Turkish students' (age 15 or older) interest in chemistry by analysing 1027 of their self-generated chemistry-related questions, which had been submitted to a popular science magazine. These questions were classified based on the field of interest, the cognitive level of the question, and the stimulating impetus for asking the question. In addition, gender-related patterns were noted in these three categories. Those results demonstrated that males asked overwhelmingly more questions than females in an informal setting. In general, students mostly asked questions about "states of matter and solutions" and "nuclear chemistry and chemistry of the elements." Most of the students asked for the properties of a variable and sought to learn about factual and explanatory types of information. The driving factors that led students to ask questions were mostly non-applicative stimulus. Significant differences emerged in some categories. For example, while males were more interested in comparison and causal relationships, females were more interested in specific information about properties. Moreover, while males tended toward seeking methodological information, making predictions, asking open-ended questions, and making general requests for information, females were more interested than males in factual and explanatory types of information. The implications of students' self-generated chemistry questions for science curriculum reform and teaching are discussed in this paper. © the Partner Organisations 2014

Laboratory evaluation of cemented backfill materials for mines

A brief state-of-the-art review is given on backfill materials and laboratory tests. A new system developed for testing backfill material in the laboratory is described. In this system, most of the limitations of previously applied techniques have been eliminated. In performing unconfined-deformability tests (UDT) and confined-deform ability tests (CDT), large cylindrical specimens having a diameter of 600 mm are used. The specimens were prepared from riverbed sand and gravel mixed with cement. A total of 135 UDT and 127 CDT specimens were tested in order to investigate the strength and deformability characteristics of 40 different combinations of backfill mixture. Calculation methods are evaluated in terms of stress-strain plots and are illustrated with examples. Typical results are presented. Two sets of deformation data can be obtained during testing: one from between the top and bottom plates, and the other from between the rings peripherally fixed onto the specimen. It is shown in this study that ring-to-ring readings provide more reliable modulus results