131,463 research outputs found
Interview with Harold Boller
No full textAn interview with Harold D. Boller about horse racing. Audio is on tape MS016_17-1_76-007https://scholars.fhsu.edu/koh/1552/thumbnail.jp
July-December -- 1967 -- Correspondence, Miscellaneous -- letter, 1967-11-02
No full textLetter from Boller, William D. to Sabin, Albert B. dated 1967-11-02.Sabin Collection Fair Use Policy</a
Italian neuropsychology in the second half of the twentieth century.
No full textSince the early 1960s, human neuropsychology, the study of brain-behavior interrelations, mainly based on the analysis of their pathological variations, brought about by brain damage, has had a remarkable systematical development in Italy. All this started in Milan, with the neurologist Ennio de Renzi, and his collaborators (Luigi Vignolo, then Anna Basso, Pietro Faglioni, Hans Spinnler, François Boller, and, more autonomously, Edoardo Bisiach), in the Clinic of Nervous and Mental Diseases. Scientists of the “Milan group” investigated several neuropsychological deficits caused by focal hemispheric lesions in large series of left- and right-brain-damaged patients, and control participants, comparable for cultural and demographic variables. Standardized tests and advanced statistical methods were used, which also applied to the diagnosis and rehabilitation of aphasia. Subsequently, neuropsychology developed in Italy extensively, reaching high international reputation. Leading neuropsychologists have been the neurologists Guido Gainotti (Rome), and Franco Denes (Padua), the physicians and psychologists Luigi Pizzamiglio (Rome), and Carlo Umiltà (Parma, with fruitful interactions with the neurophysiologists Giovanni Berlucchi, Giacomo Rizzolatti, and Carlo Marzi, from the school of Giuseppe Moruzzi in Pisa) A second scientific generation of neuropsychologists has then developed in the 1970s, trained by the abovementioned scientists, further boosting and spreading high-level basic and applied research (diagnosis and rehabilitation of neuropsychological deficits of patients with brain damage or dysfunction throughout the life span, from childhood to the elderly). Available techniques include structural and functional imaging (CT, PET, SPET, MRI and fMRI Scans, DTI), electrophysiological recording (EEG, ERPs), non-invasive brain stimulation (TMS, tES), and their combined use
Annual Meeting of the Rummy Club, Faulkton SD, Faulk County
No full text3.5 x 5.5 postcard, row of young men and a boy sitting on the stoop of a building, most of the men are wearing hatsTowns Farmingdale - Forest City P13 Poster board Faulkton, S. D. P13 [stamp] Property of: South Dakota State Historical Society Pierre, South Dakota [stamp] Give photo credit to: South Dakota State Historical Society.Faulkton, S. D. "Rummy Club" 1916 Harold Burr: Wm. Dean (boy) Max Moore: Andy Boller, Jr.; Manning Moore; Wm. Niemeyer; Hamilton Thorn; Thos. Bonney.Annual Meeting Faulkton Rummy Club 191
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Effects of trehalose on gene expression in "Arabidopsis thaliana" seedlings : a genome-wide analysis
No full textTrehalose (α-D-glucopyranosyl-[1,1]-α-D-glucopyranoside), a non reducing disaccharide
consisting of two glucose units is present in a large variety of organisms such as bacteria,
fungi and invertebrate animals where it may serve as a storage compound or stress
protectant. Trehalose also accumulates in a few desiccation-tolerant ‘resurrection plants’
and may have similar functions there. However, in almost all higher plants, including the
model plant Arabidopsis thaliana, trehalose is only present in hardly detectable amounts.
Nevertheless, plants contain several genes for each of the two enzymes required for
trehalose synthesis, and an Arabidopsis mutant lacking one of these genes is embryolethal.
It is therefore interesting to investigate the possible physiological roles of trehalose
in plants. For this purpose A. thaliana seedlings were incubated with trehalose, and the
effects on gene transcript levels were studies at the whole-genome scale. Some of the
transcripts most strongly induced by trehalose were selected for a detailed analysis, and
their expression was studied by quantitative PCR.
It has recently been shown by others, working also with A. thaliana, that several effects
of exogenous application of trehalose can be mimicked by genetic manipulations leading
to enhanced endogenous trehalose-6-phosphate (T6P) levels, and that trehalose
application indeed rises the endogenous T6P level. (This effect might result from a
feedback inhibition of trehalose-6-phophate phosphatase when intracellular trehalose
levels are high.) Thus, the changes in gene expression triggered by trehalose application
may be due to an increase in intracellular T6P concentrations rather than to an increase in
trehalose levels per se.
A problem of trehalose application, as used by others and initially also in this thesis, is
the ubiquitous occurrence of trehalase activity in plants, an enzyme most likely present in
the cell wall. This enzyme reduces exogenous trehalose levels and generates glucose,
making it difficult to interpret data on exogenous trehalose application. To prevent this, in
the main part of the thesis, trehalose was applied in combination with the potent trehalase
inhibitor validamycin A (val). In the presence of validamycin A, application of 2-4 mM
trehalose was sufficient to alter gene expression in a similar way as application of 25 mM
alone.
In this work it is shown that 25 mM trehalose added in combination with val (tre/val)
caused a two fold or more up or down regulation of 2277 genes of which more than a
third was also regulated by abscisic acid (ABA), linking trehalose metabolism to ABA
metabolism or ABA signalling. In the ABA deficient Arabidopsis mutant aba1, selected
genes inducible by tre/val and ABA still could be induced by tre/val, indicating ABA and
ABA metabolism not to be necessary to induce ABA regulated genes upon tre/val
treatment. The qualitative difference of the kinetic induction curve of gene expression
over time after tre/val application for the genes inducible by tre/val and ABA compared
to the induction curve after ABA treatment further supports the hypothesis the tre/val
induction is independent of ABA. Interestingly, the induction of some of these by tre/val
and ABA inducible genes was suppressed in abi2-1, a mutant impaired in the ABA
response. Therefore, it can be suggested that ABI2 is necessary for the regulation of at
least some genes induced by tre/val. The results obtained by the two ABA mutants
suggest the signalling cascade triggered by tre/val affects the ABA signalling pathway
downstream of the ABA binding site but upstream of ABI2 activity.
Classification of the genes up regulated by tre/val but not by ABA revealed a set of genes
involved in disease resistance and secondary metabolism indicating trehalose in
combination with validamycin A may act as an elicitor in plants.
Sugars such as sucrose (suc), glucose and fructose serve in plants not only as important
intermediates in the primary metabolism, carbon sources or substrates for storage
compounds like starch and cellulose, but can also act as signalling molecules in a similar
way as trehalose/trehalose-6-phosphate. Plant cells can sense these sugars via either a
hexokinase-dependent, or -independent system. The signal transduction pathways of both
these systems include protein phosphatases (PPs) and protein kinases (PKs).
One gene that is readily induced by suc is the one encoding sucrose:fructan 6-
fructosyltransferase (6-SFT) in barley, a key enzyme in fructan synthesis. The promoter
of this gene was studied in excised barley leaves and transformed Arabidopsis bearing a
GUS reporter gene driven by a region of the barley 6-SFT promoter. The broad-spectrum
kinase inhibitor K252a as well as genistein (GEN), an inhibitor thought to be specific for
protein tyrosine kinases in animal systems, were able to reduce the Suc induced
activation of the 6-SFT promoter in both systems, indicating that PKs are involved in Suc
mediated regulation. Interestingly, staurosporine (STAU), an inhibitor of PKs similar to
K252a did not affect Suc induction, indicating a degree of specificity of these inhibitors.
A strong reduction of Suc triggered induction of 6-SFT expression was caused by 1 μM
of the potent PP inhibitor okadaic acid (OK). This suggests that PP2A activity is also
involved in the Suc mediated regulation of the 6-SFT promoter
Wiederholen in der gymnasialen Oberstufe – wissenschaftliche Befunde und pädagogische Unterstützungsmöglichkeiten.
No full textBoller S, Möller M, Palowski M. Wiederholen in der gymnasialen Oberstufe – wissenschaftliche Befunde und pädagogische Unterstützungsmöglichkeiten. In: Bosse D, Eberle F, Schneider-Taylor B, eds. Standardisierung in der gymnasialen Oberstufe. Wiesbaden: VS/Springer; 2013: 175-188
Characterization of flagellin perception in "Arabidopsis thaliana"
No full textAt the time when this work was started, a highly sensitive perception system for bacterial flagellin in plant cells had been described (Felix et al, 1999), and FLS1 and FLS2, had been identified in A. thaliana as essential loci for flagellin perception (Gómez-Gómez et al, 1999; Gómez-Gómez and Boller, 2000). In addition, radioactive binding studies had been established for tomato to characterize the flagellin binding site (Meindl et al, 2000). It became necessary to establish binding studies for A. thaliana as well, in order to assess if mutations in FLS2, causing insensitivity to flagellin, correlated with impairment in binding. Beyond the biochemical characterization of the flagellin binding site in A. thaliana, the goal of this work was to find out if the putative flagellin receptor FLS2 is the flagellin binding site. The A. thaliana flagellin binding site was found to exhibit the biochemical characteristics of a bona fida flagellin receptor: Binding was saturable and exhibited high affinity. It exhibited specificity for flagellin-derived peptides with biological activity as agonists or antagonists of the elicitor responses. Activation of flagellin receptor in A. thaliana appeared to occur as a two step process according to the addressmessage concept with the N-terminal part required for binding (address) and the Cterminal part for activation (message), as proposed for tomato before (Meindl et al, 2000). Additionally, sensitivity to salt and pH were determined, and reversibility was found to increase during cell fractionation, indicating that disassembly of a receptor complex or loss of cofactors take place. Furthermore, it was concluded that the flagellin binding site is localized at the plasma membrane. Comparison between the characteristics of flagellin binding in A. thaliana and tomato revealed that they show clear overall similarity but exhibit characteristic differences in detail, for instance in specificity, reversibility and sensitivity to pH and salts. The elution pattern from the ion exchange column indicated that two subclasses of the binding site occur. Concanavalin A chromatography showed, that the binding site is glycosylated, and optimization of ligand affinity chromatography paved the way for the identification of the binding site in future. Binding assays in extracts of different ecotypes and La-er FLS2 mutants showed a tight
correlation between the presence of the binding site and sensitivity to flagellin,
providing further evidence that the characterized binding site acts as the physiological
receptor. Moreover, these results showed the pivotal role of FLS2 for flagellin binding.
One mutation causing impairment of flg22 binding was localized in the LRR domain,
indicating that this site might be involved in direct flagellin binding. Surprisingly, four
mutations that disrupted binding, affected the cytoplasmic kinase domain. The
significance of this finding is not understood yet. We speculated that the kinase activity
might be important for proper targeting of FLS2 or for formation of a functional
receptor complex.
In order to prove that FLS2 is the flagellin binding site, epitope-tagged FLS2 was
introduced into A. thaliana and tomato cell cultures and plants. When introduced into
fls2 mutants, this construct complemented the mutation. However, properties of
FLS2:myc protein, detected by immuno blot techniques, clearly differed from the
properties of the flagellin binding site. Nevertheless, specificity of FLS2:myc transgenic
tomato cell cultures for flagellin-derived peptides carried characteristic traits of A.
thaliana binding and elicitor-response. This finding suggests that FLS2 determines
specificity of flagellin perception. Another interesting aspect of this finding is that FLS2
seems compatible with tomato signal transduction components. It will be interesting to
find out which part of FLS2 is responsible for the differences of flagellin perception,
and which part is conserved in the two species.
Although the results presented in this work clearly demonstrate an essential role of
FLS2 for flagellin binding, direct evidence that FLS2 is the flagellin binding site is still
lacking. Binding studies with heterologously expressed FLS2 could contribute to
clearing this point. Also, optimization of the experimental conditions in order to prove
flagellin binding by solubilized FLS2 could be reasonable. Alternatively, purification of
the flagellin binding site would represent an independent approach. This method, like
partial purification of FLS2, could provide further information’s about additional
components of the receptor complex. It is likely that several components are needed for
flagellin perception, as found for the CLAVATA and the self-incompatibility perception
systems (for review see introduction)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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