1,893 research outputs found
On biogeochemical processes influencing eutrophication and toxicity in riverine wetlands
No full textContains fulltext :
74434.pdf (Publisher’s version ) (Open Access)Radboud University Nijmegen, Aquatic Ecology and Environmental Biology, 05 november 2008Promotor : Roelofs, P.d.J.G.M.173 p
To boost or not to boost: How functional plant groups and warming influence aquatic greenhouse gas emissions
No full textContains fulltext :
207511.pdf (Publisher’s version ) (Open Access)Radboud University, 15 oktober 2019Promotores : Lamers, L.P.M., Roelofs, J.G.M. Co-promotor : Kosten, S.261 p
Phosphorylation of the C-terminal tail of proteasome subunit ?7 is required for binding of the proteasome quality control factor Ecm29
No full textCitation: Wani, P. S., Suppahia, A., Capalla, X., Ondracek, A., & Roelofs, J. (2016). Phosphorylation of the C-terminal tail of proteasome subunit ?7 is required for binding of the proteasome quality control factor Ecm29. Scientific Reports, 6. doi:10.1038/srep27873The proteasome degrades many short-lived proteins that are labeled with an ubiquitin chain. The identification of phosphorylation sites on the proteasome subunits suggests that degradation of these substrates can also be regulated at the proteasome. In yeast and humans, the unstructured C-terminal region of ?7 contains an acidic patch with serine residues that are phosphorylated. Although these were identified more than a decade ago, the molecular implications of ?7 phosphorylation have remained unknown. Here, we showed that yeast Ecm29, a protein involved in proteasome quality control, requires the phosphorylated tail of ?7 for its association with proteasomes. This is the first example of proteasome phosphorylation dependent binding of a proteasome regulatory factor. Ecm29 is known to inhibit proteasomes and is often found enriched on mutant proteasomes. We showed that the ability of Ecm29 to bind to mutant proteasomes requires the ?7 tail binding site, besides a previously characterized Rpt5 binding site. The need for these two binding sites, which are on different proteasome subcomplexes, explains the specificity of Ecm29 for proteasome holoenzymes. We propose that alterations in the relative position of these two sites in different conformations of the proteasome provides Ecm29 the ability to preferentially bind specific proteasome conformations
A Second Species of the Genus Cholomus Roelofs (Curculionidae) from Central America
No full textVíquez, Carlos, Anderson, Robert S. (2004): A Second Species of the Genus Cholomus Roelofs (Curculionidae) from Central America. The Coleopterists Bulletin 58 (3): 369-371, DOI: 10.1649/626, URL: http://dx.doi.org/10.1649/62
Goal-referenced selection of verbal action: Modeling attentional control in the Stroop task
No full textItem does not contain fulltextThis article presents a new account of the Stroop phenomenon (J. R. Stroop, 1935) based on an implemented model of word production, WEAVER++ (W. J. M. Levelt, A. Roelofs, & A. S. Meyer, 1999b; A. Roelofs, 1992, 1997c). Stroop effects are claimed to arise from processing interactions within the language-production architecture and explicit goal-referenced control. WEAVER++ successfully simulates 16 classic data sets, mostly taken from the review by C. M. MacLeod (1991), including incongruency, congruency, reverse-Stroop, response-set, semantic-gradient, time-course, stimulus, spatial, multiple-task, manual, bilingual, training, age, and pathological effects. Three experiments tested the account against alternative explanations. It is shown that WEAVER++ offers a more satisfactory account of the data than other models
Physiological and Molecular Characterization of Hydroxyphenylpyruvate Dioxygenase (HPPD)-inhibitor Resistance in Palmer Amaranth (Amaranthus palmeri S.Wats.)
No full textCitation: Nakka, S., Godar, A. S., Wani, P. S., Thompson, C. R., Peterson, D. E., Roelofs, J., & Jugulam, M. (2017). Physiological and Molecular Characterization of Hydroxyphenylpyruvate Dioxygenase (HPPD)-inhibitor Resistance in Palmer Amaranth (Amaranthus palmeri S. Wats.). Frontiers in Plant Science, 8, 12. doi:10.3389/fpls.2017.00555Herbicides that inhibit hydroxyphenylpyruvate dioxygenase (HPPD) such as mesotrione are widely used to control a broad spectrum of weeds in agriculture. Amaranthus palmeri is an economically troublesome weed throughout the United States. The first case of evolution of resistance to HPPD-inhibiting herbicides in A. palmeri was documented in Kansas (KS) and later in Nebraska (NE). The objective of this study was to investigate the mechansim of HPPD-inhibitor (mesotrione) resistance in A. palmeri. Dose response analysis revealed that this population (KSR) was 10-18 times more resistant than their sensitive counterparts (MSS or KSS). Absorbtion and translocation analysis of [C-14] mesotrione suggested that these mechanisms were not involved in the resistance in A. palmeri. Importantly, mesotrione (>90%) was detoxified markedly faster in the resistant populations (KSR and NER), within 24 hours after treatment (HAT) compared to sensitive plants (MSS, KSS, or NER). However, at 48 HAT all populations metabolized the mesotrione, suggesting additional factors may contribute to this resistance. Further evaluation of mesotrione-resistant A. palmeri did not reveal any specific resistance-conferring mutations nor amplification of HPPD gene, the molecular target of mesotrione. However, the resistant populations showed 4- to 12-fold increase in HPPD gene expression. This increase in HPPD transcript levels was accompanied by increased HPPD protein expression. The significant aspects of this research include: the mesotrione resistance in A. palmeri is conferred primarily by rapid detoxification (non-target-site based) of mesotrione; additionally, increased HPPD gene expression (target-site based) also contributes to the resistance mechanism in the evolution of herbicide resistance in this naturally occurring weed species
VEMH
No full textTelemcdicinc aims at equal access to medical expertise irrespective of the geographical location of the person in need. New developments in Information and Communication Technologies (JCT) have enabled the transmission of medical images in sufficiently high quality, which allows for a reliable diagnosis to be determined by the expert at the receiving site (Pande, Patel, Powers, D'Ancona & Karamanoukian, 2003; Lacroix et al., 2002). At the same time, however, these innovative developments in ICT over the last decade bear the risk of creating and amplifying a digital divide in the world, creating a disparity between the northern and southern Euro-Mediterranean areas (Dario etal., 2005; Graschew, Rakowsky, Roelofs & Schlag, 2003a; Graschew, Roelofs, Rakowsky & Schlag, 2004 ). In recent years, various institutions have started Euro-Mediterranean telemedicine projects (EMISPHER, www.emispher.org/; BURNET, www.burnet.org/; PARADIGMA, www.paradigmamed.org; EMPHIS, www.emphis.org/; EUMEDGEN, www.eurogene.org; ODISEAME, www.odiseame.org; EUMEDCONNECT, www.eumedconncct.net/; GALENOS, www.rrk-berlin.de/op2000/Deutsch/projekte/galenos.html), which were intended to foster a cooperation between the European EU-Member countries and the Mediterranean countries (Graschew, Roelofs, Rakowsky, & Schlag, 2002; Graschew, Roelofs, Rakowsky, & Schlag, 2003b; Rheuban & Sullivan, 2005; Wootton, Jcbamani, & Dow, 2005). All these projects have demonstrated how the digital divide is only part of a more complex problem: the need for integration. Therefore, provision of the same advanced technologies to the European, Mediterranean, and Adhering countries should be the final goal for contributing to their better dialogue for integration
Simulation of impairment: Commentary on Nickels, Rapp, and Kohnen (2015)
No full textNickels, L., Rapp, B., and Kohnen, S. (2015. Challenges in the use of treatment to investigate cognition. Cognitive Neuropsychology, 32, 91-103) argue that impairment and treatment may be used to test computational models of cognition. They state that, contrary to their view, the authors of the WEAVER++ model of spoken word production have explicitly rejected simulation of impairment [i.e., Levelt, W. J. M., Roelofs, A., & Meyer, A. S. (1999b). Multiple perspectives on word production. Behavioral and Brain Sciences, 22, 61-69]. Here, I argue that this incorrectly characterizes the position of Levelt et al. Moreover, I further clarify this position, which holds that simulation of impairment requires both a theory of the intact system and assumptions about the underlying deficit, which is a widely accepted view. To demonstrate this position, I outline the approach taken in WEAVER++ simulations of aphasic performance reported in Roelofs, A. (2014. A dorsal-pathway account of aphasic language production: The WEAVER++/ARC model. Cortex, 59, 33-48). These simulations not only prove that the developers of WEAVER++ endorse simulation of impairment, but also highlight the importance of integrating psycholinguistic, functional neuroimaging, and tractographic evidence in testing models of impaired performance
Pteridobaris maritima Roelofs
No full textPteridobaris maritima (Roelofs) (Figs. 13, 20) Baris maritima Roelofs 1875: 181. Syntypes from Japan, without further collecting data (BMNH, NKMB, RBINS); one examined. Transferred to Pteridobaris by Morimoto & Yoshihara (1996). Baris quinquecarinata Zaslavskij 1956: 351. Holotype male, “Pekin”, without further collecting data (ZIN); examined. New synonymy. Diagnosis. Species of Pteridobaris Morimoto & Yoshihara have one distinct and several small denticles on the ventral side of the femora, most conspicuously on the profemur; most other Oriental genera with armed femora have single or paired denticles. Pteridobaris maritima (Fig. 13) has five dorsal carinae on the rostrum, which are absent in a similar, undescribed species from Hainan, China (HBU, IZCAS). Morimoto & Yoshihara (1996) mentioned six undescribed species from Taiwan, the Philippines, Thailand and Malaya. Notes. Zaslavskij (1956) distinguished B. quinquecarinata from B. maritima based on the dorsally carinate rostrum. We examined the types and found no difference, although the carination can be more subtle in females. Distribution. The species occurs in S China (Fujian, Guangxi, Guizhou, Hong Kong), Japan and Vietnam (Fig. 20). The record from Beijing (Zaslavskij 1956) is unconfirmed. Biology. Nothing is known about the life history of Pteridobaris species except that P. maritima and an undescribed species have been collected from ferns (Morimoto & Yoshihara 1996). The only other known baridines associated with ferns are species of the New World genera Lamprobaris Champion and Lissobaris Champion (A. Howden, J. Prena, unpubl. data). Material examined. CHINA. Beijing: “Pekin”, without collecting data (ZIN 1). Fujian: Buyun Village, Shanghang, 31.v. 2004 (IZCAS 1); Huangkeng Guilin, Jianyang, 14.iv. 1960 (IZCAS 1); Jianyang, 12.v. 1965 (IZCAS 1); Xingcun, Wuyishan, Nanping, 21.iv. 2009 (ZAFU 1). Guangxi: Daming Mountain Natural Reserve, 25.– 26.v. 2011 (IZCAS 3); Dongzhong Forest Farm, Fangcheng, Fangchenggang, 9.iv. 2002 (HBU 1); Hongqi Forestry Centre, 18.iii. 1998 (IZCAS 3); Napo Baihe, 7.iv. 1998 (IZCAS 2); Napo Defu, 4.iv. 1998 (IZCAS 5); Xialeizhen, Daxin, Chongzuo, 31.iii. 1998 (IZCAS 1). Guizhou: Xishui Sancha River, 29.v. 2000 (IZCAS 1). Hong Kong: Mui Wo, Lantau Island, 13.iv. 2013 (IZCAS 1); Tai Mo Shan, 15.iv. 2013 (IZCAS 4). Shanghai: (SNSD 1). JAPAN. Without locality data (NHMB 1, NKMB 1, SNSD 1). VIETNAM. Tinh Vinh Phuc: Tam Dao, 12.vi. 1994, 19.v. 1995 (ZIN 2). “ Tonkin ”, Manson Mts. (MNKB 3).Published as part of Prena, Jens, Yang, Jiani, Ren, Li, Wang, Zhiliang, Liu, Ning & Zhang, Runzhi, 2014, Nomenclatural changes, new country records and range extensions of Baridinae (Coleoptera, Curculionidae) from China, pp. 339-363 in Zootaxa 3841 (3) on page 352, DOI: 10.11646/zootaxa.3841.3.2, http://zenodo.org/record/22625
Mesenchymal stem cells for the management of rheumatoid arthritis: Immune modulation, repair or both?
No full textPurpose of review Mesenchymal stromal/stem cells (MSCs) have potent anti-inflammatory and immunomodulatory properties, in addition to their ability to form cartilage and bone. The purpose of this review is to highlight recent developments and current knowledge gaps in our understanding of the protective effects of MSCs against inflammatory arthritis, and to discuss their clinical exploitation for the treatment of rheumatoid arthritis (RA). Recent findings The weight of evidence for protective mechanisms of exogenously administered MSCs is on immunomodulatory effects, including inhibition of dendritic cell maturation, polarization of macrophages to an anti-inflammatory phenotype, and activation of regulatory T cells, thereby dampening inflammation and preventing joint damage. Evidence for direct effects on tissue repair is scant. Recent studies have identified MSC subsets in vivo and an important question is whether MSCs in their native tissues have similar immunoregulatory functions. Recent proof-of-concept clinical studies have shown a satisfactory safety profile of allogeneic MSC therapy in RA patients with promising trends for clinical efficacy. Summary Allogeneic MSCs could be effective in RA. Larger, multicentre clinical studies are needed to provide robust evidence, and MSC treatment at early stages of RA should be explored to 'reset' the immune system
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