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1

Leaf Petiole and Stem Blight Disease of Sweet Potato Caused by Alternaria Bataticola in Uganda  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria leaf petiole and stem blight is an important disease of sweet potato (Ipomoea batatus (L.) Lam.) in tropical and sub-tropical regions. In surveys conducted in Uganda from 2001 to 2003, disease incidence ranged from 0-49%. Symptoms of Alternaria leaf and stem blight disease consisted of sm...

2

Etiology of the resinous stem canker of Chamaecyparis obtusa: Cistella japonica as the causal agent  

Microsoft Academic Search

In order to confirm the pathogenicity ofCistella japonica, inoculation experiments were conducted onto several coniferous trees. Resinous lesions similar to those of the resinous\\u000a stem canker developed by the inoculation withCi. japonica only onChamaecyparis obtusa. Chamaecyparis trees were heavily affected when inoculated with the fungus in November, but slightly in May and August. Resin flows occurred\\u000a when inocula ofCi. japonica

Yasuo Suto

1997-01-01

3

Rhizoctonia damping off stem canker and root rot  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia solani has been reported to cause damping-off and root rot of rhododendrons and azaleas. Damping-off often includes groups of dying and dead seedlings. Decline of rooted plants in containers results from both root rot and stem necrosis below or above the soil line. Root rot is usually no...

4

Assessing quantitative resistance against Leptosphaeria maculans (phoma stem canker) in Brassica napus (oilseed rape) in young plants.  

PubMed

Quantitative resistance against Leptosphaeria maculans in Brassica napus is difficult to assess in young plants due to the long period of symptomless growth of the pathogen from the appearance of leaf lesions to the appearance of canker symptoms on the stem. By using doubled haploid (DH) lines A30 (susceptible) and C119 (with quantitative resistance), quantitative resistance against L. maculans was assessed in young plants in controlled environments at two stages: stage 1, growth of the pathogen along leaf veins/petioles towards the stem by leaf lamina inoculation; stage 2, growth in stem tissues to produce stem canker symptoms by leaf petiole inoculation. Two types of inoculum (ascospores; conidia) and three assessment methods (extent of visible necrosis; symptomless pathogen growth visualised using the GFP reporter gene; amount of pathogen DNA quantified by PCR) were used. In stage 1 assessments, significant differences were observed between lines A30 and C119 in area of leaf lesions, distance grown along veins/petioles assessed by visible necrosis or by viewing GFP and amount of L. maculans DNA in leaf petioles. In stage 2 assessments, significant differences were observed between lines A30 and C119 in severity of stem canker and amount of L. maculans DNA in stem tissues. GFP-labelled L. maculans spread more quickly from the stem cortex to the stem pith in A30 than in C119. Stem canker symptoms were produced more rapidly by using ascospore inoculum than by using conidial inoculum. These results suggest that quantitative resistance against L. maculans in B. napus can be assessed in young plants in controlled conditions. Development of methods to phenotype quantitative resistance against plant pathogens in young plants in controlled environments will help identification of stable quantitative resistance for control of crop diseases. PMID:24454767

Huang, Yong-Ju; Qi, Aiming; King, Graham J; Fitt, Bruce D L

2014-01-01

5

Canker Sores  

MedlinePLUS

... Million NIDCR/NIH Grant 2015 AAOM Call for Abstract Submissions Upcoming Events 2015 Annual Conference Registration is Now Open 2016 Annual Meeting in Atlanta - Save the Date! Canker Sores Canker ...

6

Involvement of microRNA-Mediated Gene Expression Regulation in the Pathological Development of Stem Canker Disease in Populus trichocarpa  

PubMed Central

MicroRNAs (miRNAs), a type of short (21–23 nucleotides), non-coding RNA molecule, mediate repressive gene regulation through RNA silencing at the post-transcriptional level, and play an important role in defense and response to abiotic and biotic stresses. In the present study, Affymetrix® miRNA Array, real-time quantitative PCR (qPCR) for miRNAs and their targets, and miRNA promoter analysis were used to validate the gene expression patterns of miRNAs in Populus trichocarpa plantlets induced with the poplar stem canker pathogen, Botryosphaeria dothidea. Twelve miRNAs (miR156, miR159, miR160, miR164, miR166, miR168, miR172, miR319, miR398, miR408, miR1448, and miR1450) were upregulated in the stem bark of P. trichocarpa, but no downregulated miRNAs were found. Based on analysis of the miRNAs and their targets, a potential co-regulatory network was developed to describe post-transcriptional regulation in the pathological development of poplar stem canker. There was highly complex cross-talk between diverse miRNA pathway responses to biotic and abiotic stresses. The results suggest that miR156 is probably an integral component of the miRNA response to all environmental stresses in plants. Cis-regulatory elements were binding sites for the transcription factors (TFs) on DNA. Promoter analysis revealed that TC-rich repeats and a W1-box motif were both tightly related disease response motifs in Populus. Promoter analysis and target analysis of miRNAs also revealed that some TFs regulate their activation/repression. Furthermore, a feedback regulatory network in the pathological development of poplar stem canker is provided. The results confirm that miRNA pathways regulate gene expression during the pathological development of plant disease, and provide new insights into understanding the onset and development of poplar stem canker. PMID:23028709

Zhao, Jia-Ping; Jiang, Xiao-Ling; Zhang, Bing-Yu; Su, Xiao-Hua

2012-01-01

7

Alternaria redefined  

PubMed Central

Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always correlate to species-groups based on morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera based on nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and six monotypic lineages, the assemblage of which we recognise as Alternaria. This puts the genera Allewia, Brachycladium, Chalastospora, Chmelia, Crivellia, Embellisia, Lewia, Nimbya, Sinomyces, Teretispora, Ulocladium, Undifilum and Ybotromyces in synonymy with Alternaria. In this study, we treat the 24 internal clades in the Alternaria complex as sections, which is a continuation of a recent proposal for the taxonomic treatment of lineages in Alternaria. Embellisia annulata is synonymised with Dendryphiella salina, and together with Dendryphiella arenariae, are placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, which were previously associated with Alternaria, cluster within the Pleosporaceae, outside Alternaria s. str., whereas Alternariaster, a genus formerly seen as part of Alternaria, clusters within the Leptosphaeriaceae. Paradendryphiella is newly described, the generic circumscription of Alternaria is emended, and 32 new combinations and 10 new names are proposed. A further 10 names are resurrected, while descriptions are provided for 16 new Alternaria sections. Taxonomic novelties: New combinations - Alternaria abundans (E.G. Simmons) Woudenb. & Crous, Alternaria alternariae (Cooke) Woudenb. & Crous, Alternaria atra (Preuss) Woudenb. & Crous, Alternaria bornmuelleri (Magnus) Woudenb. & Crous, Alternaria botrytis (Preuss) Woudenb. & Crous, Alternaria caespitosa (de Hoog & C. Rubio) Woudenb. & Crous, Alternaria cantlous (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria caricis (E.G. Simmons) Woudenb. & Crous, Alternaria cinerea (Baucom & Creamer) Woudenb. & Crous, Alternaria didymospora (Munt.-Cvetk.) Woudenb. & Crous, Alternaria fulva (Baucom & Creamer) Woudenb. & Crous, Alternaria hyacinthi (de Hoog & P.J. Mull. bis) Woudenb. & Crous, Alternaria indefessa (E.G. Simmons) Woudenberg & Crous, Alternaria leptinellae (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria lolii (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria multiformis (E.G. Simmons) Woudenb. & Crous, Alternaria obclavata (Crous & U. Braun) Woudenb. & Crous, Alternaria obovoidea (E.G. Simmons) Woudenb. & Crous, Alternaria oudemansii (E.G. Simmons) Woudenb. & Crous, Alternaria oxytropis (Q. Wang, Nagao & Kakish.) Woudenb. & Crous, Alternaria penicillata (Corda) Woudenb. & Crous, Alternaria planifunda (E.G. Simmons) Woudenb. & Crous, Alternaria proteae (E.G. Simmons) Woudenb. & Crous, Alternaria scirpinfestans (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria scirpivora (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria septospora (Preuss) Woudenb. & Crous, Alternaria slovaca (Svob.-Pol., L. Chmel & Bojan.) Woudenb. & Crous, Alternaria subcucurbitae (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria tellustris (E.G. Simmons) Woudenb. & Crous, Alternaria tumida (E.G. Simmons) Woudenb. & Crous, Paradendryphiella salina (G.K. Sutherl.) Woudenb. & Crous, Paradendryphiella arenariae (Nicot) Woudenb. & Crous. New names - Alternaria aspera Woudenb. & Crous, Alternaria botryospora Woudenb. & Crous, Alternaria brassicae-pekinensis Woudenb. & Crous, Alternaria breviramosa Woudenb. & Crous, Alternaria chlamydosporigena Woudenb. & Crous, Alternaria concatenata

Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

2013-01-01

8

Alternaria blight  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria blight of chickpea is caused by the fungal pathogen Alternaria alternata. The pathogen has wide host range, and affects all above ground parts of the plant. The disease occurs sporadically and occasionally could be economically important and causes significant damage. The pathogen can ...

9

Myrothecium roridum leaf spot and stem canker on watermelon in the southern Great Plains: Possible factors for its outbreak  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diseases are generally the greatest yield-limiting factor for watermelon across the U.S. In 2010, a foliar and stem-lesion disease was observed for the first time in Oklahoma causing moderate to severe defoliation. Using microscopic examination, the physical features of the fungus were consistent ...

10

Canker Sores (For Parents)  

MedlinePLUS

... nutritional deficiencies of folic acid, vitamin B12, and iron seem to develop canker sores more often, as ... open sores that have a white or yellowish coating and a red "halo" around them. They tend ...

11

Most AAL toxin-sensitive Nicotiana species are resistant to the tomato fungal pathogen Alternaria alternata f. sp. lycopersici.  

PubMed

The phytopathogenic fungus Alternaria alternata f. sp. lycopersici produces AAL toxins required to colonize susceptible tomato (Lycopersicon esculentum) plants. AAL toxins and fumonisins of the unrelated fungus Fusarium moniliforme are sphinganine-analog mycotoxins (SAMs), which are toxic for some plant species and mammalian cell lines. Insensitivity of tomato to SAMs is determined by the Alternaria stem canker gene 1 (Asc-1), and sensitivity is associated with a mutated Asc-1. We show that SAM-sensitive species occur at a low frequency in the Nicotiana genus and that candidate Asc-1 homologs are still present in those species. In Nicotiana spp., SAM-sensitivity and insensitivity also is mediated by a single codominant locus, suggesting that SAM-sensitive genotypes are host for A. alternata f. sp. lycopersici. Nicotiana umbratica plants homozygous for SAM-sensitivity are indeed susceptible to A. alternata f. sp. lycopersici. In contrast, SAM-sensitive genotypes of Nicotiana spegazzinii, Nicotiana acuminata var. acuminata, Nicotiana bonariensis, and Nicotiana langsdorffii are resistant to A. alternata f. sp. lycopersici infection concomitant with localized cell death. Additional (nonhost) resistance mechanisms to A. alternata f. sp. lycopersici that are not based on an insensitivity to SAMs are proposed to be present in Nicotiana species. PMID:11310733

Brandwagt, B F; Kneppers, T J; Van der Weerden, G M; Nijkamp, H J; Hille, J

2001-04-01

12

Host switching between native and non-native trees in a population of the canker pathogen Chrysoporthe cubensis  

E-print Network

Host switching between native and non-native trees in a population of the canker pathogen of this study was to test the hypothesis that Chrysoporthe cubensis on native trees in South America could Chrysoporthe canker is an economically important stem disease of plantation-grown Eucalyptus species in the tro

13

TPCP: Cryphonectria canker of Eucalyptus CRYPHONECTRIA CANKER OF  

E-print Network

of Eucalyptus in areas of the world where these trees are grown as exotics in plantations. Although the fungus and has already resulted in the elimination of a number of valuable Eucalyptus clones. Cracked tree crown typical of infection on older trees. SYMPTOMS AND OCCURRENCE In South Africa, Cryphonectria canker

14

Clinical characteristics of alternaria keratitis.  

PubMed

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Hsiao, Ching-Hsi; Yeh, Lung-Kun; Chen, Hung-Chi; Lin, Hsin-Chiung; Chen, Phil Y F; Ma, David H K; Tan, Hsin-Yuan

2014-01-01

15

Clinical Characteristics of Alternaria Keratitis  

PubMed Central

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Lin, Hsin-Chiung; Chen, Phil Y. F.; Ma, David H. K.; Tan, Hsin-Yuan

2014-01-01

16

The HPLC-Fluorescence Detection of Coumarins in ‘Hamlin’ Sweet Orange and ‘Marsh’ Grapefruit Leaf Cankers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Canker is a devastating disease for the citrus fresh fruit market and is caused by the pathogenic bacterium Xanthomonas citri var. citri (Xcc). Infection occurs by bacterial penetration through physical damage of leaves, peel and stems, and also by bacterial entry through the stomates of these photo...

17

Morphological, Pathogenic, and Molecular Characterization of Alternaria Isolates Associated with Alternaria Late Blight of Pistachio  

Microsoft Academic Search

ABSTRACT Pryor, B. M., and Michailides, T. J. 2002. Morphological, pathogenic, and molecular characterization of ,Alternaria isolates associated with Alternaria late blight of pistachio. Phytopathology 92:406-416. Alternaria isolates ,were ,obtained from ,various pistachio tissues

Barry M. Pryor; Themis J. Michailides

2002-01-01

18

Ethanol attracts scolytid beetles to Phytophthora ramorum cankers on coast live oak.  

PubMed

Ethanol in sapwood was analyzed along vertical transects, through small spot cankers and larger basal cankers, of Phytophthora ramorum-infected stems of Quercus agrifolia at three sites in California. Trees with large basal cankers, known to attract scolytid beetles, had a 4.3 times higher ethanol level than trees with spot cankers that attract fewer beetles. Ethanol concentrations inside cankers, where scolytid beetles preferentially attack, varied by about four orders of magnitude among samples, with a median level of 16.0 ?g.g(-1) fresh mass. This concentration was 4.3 and 15.5 times greater, respectively, than the concentrations at 1 cm or 15-30 cm outside the canker boundaries. In the laboratory, we demonstrated that ethanol escaped through the bark of a Q. garryana log just 3 days after it was added to the sapwood. At the three study sites, traps baited with ethanol captured more Xyleborinus saxesenii, Pseudopityophthorus pubipennis, and Monarthrum dentiger (all Coleoptera: Curculionidae: Scolytinae) than traps baited with ethanol plus (-)-?-pinene, or ethanol plus 4-allylanisole (4AA). Logs of Q. agrifolia with a 50 % ethanol solution added to the sapwood were placed at the study sites, with or without additional bark treatments above the ethanol. The number of scolytid beetle gallery holes above the ethanol-infused sapwood was 4.4 times greater than that on the opposite side of the log where no ethanol was added. Attachment of ultra-high release (-)-?-pinene pouches to the bark surface above the 50 % ethanol solution reduced scolytid attacks to a density of 19.1 % that of logs without this treatment. We conclude that ethanol in P. ramorum cankers functions as a primary host attractant for scolytid beetles and is an important link in colonization of these cankers and accelerated mortality of Q. agrifolia. The results of this research shed light on the chemical ecology behind the focused scolytid attacks on P. ramorum-infected coast live oaks, and lay the groundwork for future efforts to prolong the survival of individual trees of this keystone species. PMID:23525941

Kelsey, Rick G; Beh, Maia M; Shaw, David C; Manter, Daniel K

2013-04-01

19

Dynamics of Cryphonectria hypovirus infection in chestnut blight cankers.  

PubMed

Virulent strains of the chestnut blight fungus Cryphonectria parasitica cause lethal bark cankers on chestnut trees. Infection of C. parasitica with Cryphonectria hypovirus 1 in Europe biologically controls this disease, leading to nonlethal and inactive cankers. Unexpectedly, virus-free C. parasitica strains have been isolated from inactive cankers. In this study, we compared the virulence of virus-infected and virus-free C. parasitica strains isolated from either inactive or active cankers on chestnut seedlings and sprouts. In the seedling experiment, we assessed canker growth and seedling mortality. In the sprout experiment, we also assessed canker growth and made fungal reisolations to determine virus infection and immigration of foreign vegetative compatibility (vc) types over a period of 13 years in a coppice forest. Overall, the virulence of virus-free C. parasitica strains isolated from inactive versus active cankers did not differ. Significant differences were only attributed to virus infection. Virus infection and fungal strain composition in cankers changed over time. Foreign vc types immigrated into cankers and virus-free cankers became virus-infected within a few years. Most of the cankers were callused over time and became inactive. However, we observed that the virus did not always persist in these cankers. This study demonstrates that virus spread occurs effectively in European chestnut forests and that this biocontrol system is highly dynamic. PMID:24601984

Bryner, Sarah Franziska; Prospero, Simone; Rigling, Daniel

2014-09-01

20

Hyperspectral reflectance imaging for detecting citrus canker based on dual-band ratio image classification method  

NASA Astrophysics Data System (ADS)

Citrus are one of the major fruit produced in China. Most of this production is exported to Europe for fresh consumption, where consumers increasingly demand best quality. Citrus canker is one of the most devastating diseases that threaten peel of most commercial citrus varieties. The aim of this research was to investigate the potential of using hyperspectral imaging technique for detecting canker lesions on citrus fruit. Navel oranges with cankerous, normal and various common diseased skin conditions including wind scar, thrips scarring, scale insect, dehiscent fruit, phytotoxicity, heterochromatic stripe, and insect damage were studied. The imaging system (400-1000 nm) was established to acquire reflectance images from samples. Region of interest (ROI) spectral feature of various diseased peel areas was analyzed and characteristic wavebands (630, 685, and 720 nm) were extracted. The dual-band reflectance ratio (such as Q720/685) algorithm was performed on the hyperspectral images of navel oranges for differentiating canker from normal fruit skin and other surface diseases. The overall classification success rate was 96.84% regardless of the presence of other confounding diseases. The presented processing approach overcame the presence of stem/navel on navel oranges that typically has been a problematic source for false positives in the detection of defects. Because of the limited sample size, delineation of an optimal detection scheme is beyond the scope of the current study. However, the results showed that two-band ratio (Q685/630) along with the use of a simple threshold value segmentation method for discriminating canker on navel oranges from other peel diseases may be feasible.

Li, Jiangbo; Rao, Xiuqin; Guo, Junxian; Ying, Yibin

2010-10-01

21

Symptoms visible on affected trees include bleeding areas on their stems and sometimes  

E-print Network

Symptoms visible on affected trees include bleeding areas on their stems and sometimes to induce bleeding stem cankers. Sequenceing of the gyrase B gene (gyrB) has indicated the presence of the isolates from bleeding canker was found to be identical to that of Pseudomonas syringae pv aesculi (NCPPB

22

Characteristics of Multi-rater Estimates of Citrus Canker Severity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (CC, caused by Xanthomonas citri) was under eradication for 10 y in Florida. A total of 28 CC surveyors and plant pathologists rated severity of CC symptoms on 200 images to investigate the range of abilities and some factors that influence canker severity estimation. Actual dis...

23

Alternaria keratitis after deep anterior lamellar keratoplasty.  

PubMed

To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

Naik, Mekhla; Mohd Shahbaaz; Sheth, Jay; Sunderamoorthy, S K

2014-01-01

24

Alternaria Keratitis after Deep Anterior Lamellar Keratoplasty  

PubMed Central

To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

Naik, Mekhla; Mohd. Shahbaaz; Sheth, Jay; Sunderamoorthy, S. K.

2014-01-01

25

Citrus Canker: The Pathogen and Its Impact  

NSDL National Science Digital Library

This Web site, currently featured on the home page of the American Phytopathological Society, contains a research report regarding the Asiatic citrus canker that has had devastating effects on Florida's citrus industry. The report, in a journal article format, thoroughly relates the natural history and current status of the disease, as well as detailing the methods and results of the (primarily genetic) experiments conducted in this study. One of the most appealing features of this Web site is the quality of the photos within the report. These photos can be viewed separately from the report in a slide show. While navigating this site is relatively straightforward, the lack of a table of contents can make finding your place in the body of the text somewhat confusing.

2002-01-01

26

Experiments with Biocontrol of Alternaria alternata  

Technology Transfer Automated Retrieval System (TEKTRAN)

A biocontrol yeast (WRL-76) developed by USDA-ARS at the Western Regional Research lab was evaluated for control of Alternaria alternata on pistachio. The experiment was conducted over a four year period in a Madera Co., CA orchard. Counts of damaged vs. intact fruit clusters were taken on 100 contr...

27

Impacts of Phytophthora ramorum Canker and Other Agents in Sonoma County  

E-print Network

209 Impacts of Phytophthora ramorum Canker and Other Agents in Sonoma County Forests1 Tedmund J canker disease caused by Phytophthora ramorum, we established permanent plots in Sonoma County forest California, including Sonoma County. Host trees that can be killed by P. ramorum canker (sudden oak death

Standiford, Richard B.

28

First report of Neofusicoccum parvum causing canker and die-back of Eucalyptus in Spain  

E-print Network

First report of Neofusicoccum parvum causing canker and die-back of Eucalyptus in Spain Eugenia disease in Eucalyptus globulus in North Spain. Keywords Eucalyptus canker. Neofusicoccum parvum . Botryosphaeriaceae A canker disease outbreak was observed for the first time on Eucalyptus globulus in North Spain

29

Copper Sprays and Windbreaks for Control of Citrus Canker on Young Orange Trees in Southern Brazil  

Technology Transfer Automated Retrieval System (TEKTRAN)

The benefit of windbreaks and copper sprays for control of citrus canker caused by Xanthomonas axonopodis pv. citri was investigated in a commercial citrus orchard located in a citrus canker endemic area in southern Brazil. Control of canker was evaluated as incidence and severity of lesions on foli...

30

New tricycloalternarenes from fungus Alternaria sp.  

PubMed

Two new tricycloalternarenes I (1) and J (2), together with five known derivatives (3-7), were isolated from the culture of marine fungus Alternaria sp. The structures were elucidated by a combination of spectroscopic approach ((1)H, (13)C NMR, HMBC, COSY, and NOESY) and the low-temperature (100 K) single-crystal X-ray crystallography analysis. The antimicrobial assays of tricycloalternarenes I (1) and J (2) were tested. PMID:25402226

Shi, Xiu; Wei, Wei; Zhang, Wen-Jing; Hua, Cheng-Pin; Chen, Chao-Jun; Ge, Hui-Ming; Tan, Ren-Xiang; Jiao, Rui-Hua

2015-02-01

31

Infection and decontamination of citrus-canker-inoculated leaf surfaces  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Personnel and equipment decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf su...

32

Walnut Twig Beetle and Thousand Cankers Disease: Field Identification Guide  

E-print Network

, University of California, Davis, CA Tom W. Coleman, USDA Forest Service, Forest Health Protection, San examining large logs for symptoms of thousand cankers disease, first look for evidence of old sap staining. Seybold, USDA Forest Service, Pacific Southwest Research Station, Davis, CA Please cite this document as

Ishida, Yuko

33

Efficacy of Cankerguard® Sprays for Effective Decontamination of Citrus Canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is endemic in Florida. We used grapefruit leaf surfaces to explore the efficacy of the personnel decontaminant Cankerguard® to kill inoculum. In three experiments plants in flush (leaves 3/4 expanded) were sprayed with inoculum (2x104-9x105 CFU/ml)...

34

Automating the assessment of citrus canker symptoms with image analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (CC, caused by Xanthomonas citri) is a serious disease of citrus in Florida and other citrus-growing regions. Severity of symptoms can be estimated by visual rating, but there is inter- and intra-rater variation. Automated image analysis (IA) may offer a way of reducing some of ...

35

PROSPECTS FOR CONTROL OF CITRUS CANKER WITH NOVEL CHEMICAL COMPOUNDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field trials conducted in Brazil demonstrate that copper formulations (copper hydroxide, CH; copper oxychloride, COC) even at reduced rates are consistently effective for control of canker on moderately susceptible orange varieties. Contact activity to replace and/or reduce copper could minimize po...

36

First Record of Alternaria simsimi Causing Leaf Spot on Sesame (Sesamum indicum L.) in Korea  

PubMed Central

Leaf spot disease was observed in sesame (Sesamum indicum L.) during 2009 and 2010 in Korea. The pathogen was identified as Alternaria simsimi based on morphological and cultural characteristics. The morphological identification was well supported by phylogenetic analysis of the ribosomal DNA-internal transcribed spacer region. A. simsimi isolates caused spot symptoms on leaves and stems of sesame plants 2 wk after artificial inoculation, which were similar to those observed in the field. This is the first record of leaf spot disease in Korea caused by A. simsimi. PMID:25606015

Choi, Young Phil; Paul, Narayan Chandra

2014-01-01

37

Effect of fruit harvest time on citrus canker detection using hyperspectral reflectance imaging  

Microsoft Academic Search

The citrus industry has need for effective and efficient approaches to remove fruit with canker before they are shipped to\\u000a selective international markets. The objective of this research was to study the effect of fruit harvest time on citrus canker\\u000a detection using hyperspectral reflectance imaging. Ruby Red grapefruits with normal surface, canker, and five common peel\\u000a diseases including greasy spot,

Xuhui Zhao; Thomas F. Burks; Jianwei Qin; Mark A. Ritenour

2010-01-01

38

Citrus canker detection using hyperspectral reflectance imaging and PCA-based image classification method  

Microsoft Academic Search

Citrus canker is one of the most devastating diseases that threaten marketability of citrus crops. Technologies that can efficiently\\u000a identify citrus canker would assure fruit quality and safety and enhance the competitiveness and profitability of the citrus\\u000a industry. This research was aimed to investigate the potential of using hyperspectral imaging technique for detecting canker\\u000a lesions on citrus fruit. A portable

Jianwei Qin; Thomas F. Burks; Moon S. Kim; Kuanglin Chao; Mark A. Ritenour

2008-01-01

39

Large-spored Alternaria pathogens in section Porri disentangled.  

PubMed

The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia. PMID:25492985

Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

2014-09-01

40

STEM?!?!  

ERIC Educational Resources Information Center

The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

Merrill, Jen

2012-01-01

41

First report of citrus canker caused by Xanthomonas citri in Somalia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Xanthomonas citri, causal agent of citrus canker, has been reported in several countries in Africa, but not Somalia. During 2006 and 2007, hyperplasia-type lesions, often surrounded by a water-soaked margin and yellow halo, typical of citrus canker caused by X. citri, were found on 8-10 year-old gr...

42

A novel Fusarium species causes a canker disease of the critically endangered conifer, Torreya taxifolia  

Technology Transfer Automated Retrieval System (TEKTRAN)

A canker disease of Florida torreya (Torreya taxifolia), here designated CDFT, has been implicated in the decline of this critically endangered species in its native range of northern Florida and southeastern Georgia. In our current surveys of eight Florida torreya sites, cankers were present on all...

43

CITRUS CANKER: DOING BATTLE WITH THE BEAST FOR NEARLY A CENTURY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) has a long history in Florida. The disease was first found around 1910 and spread throughout the southeastern US on imported citrus seedlings from Japan. After an extensive eradication program, canker was declared eradicated from Florida and the adjacent states in 1933....

44

Automated image analysis of the severity of foliar citrus canker symptoms  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (caused by Xanthomonas citri subsp. citri) is a destructive disease, reducing yield, and rendering fruit unfit for fresh sale. Accurate assessment of citrus canker severity and other diseases is needed for several purposes, including monitoring epidemics and evaluation of germplasm. ...

45

Detecting citrus canker by hyperspectral reflectance imaging and PCA-based image classification method  

NASA Astrophysics Data System (ADS)

Citrus canker is one of the most devastating diseases that threaten citrus crops. Technologies that can efficiently identify citrus canker would assure fruit quality and safety and enhance the competitiveness and profitability of the citrus industry. This research was aimed to investigate the potential of using hyperspectral imaging technique for detecting canker lesions on citrus fruit. A portable hyperspectral imaging system consisting of an automatic sample handling unit, a light source, and a hyperspectral imaging unit was developed for citrus canker detection. The imaging system was used to acquire reflectance images from citrus samples in the wavelength range between 400 nm and 900 nm. Ruby Red grapefruits with normal and various diseased skin conditions including canker, copper burn, greasy spot, wind scar, cake melanose, and specular melanose were tested. Hyperspectral reflectance images were analyzed using principal component analysis (PCA) to compress the 3-D hyperspectral image data and extract useful image features that could be used to discriminate cankerous samples from normal and other diseased samples. Image processing and classification algorithms were developed based upon the transformed images of PCA. The overall accuracy for canker detection was 92.7%. This research demonstrated that hyperspectral imaging technique could be used for discriminating citrus canker from other confounding diseases.

Qin, Jianwei; Burks, Thomas F.; Kim, Moon S.; Chao, Kuanglin; Ritenour, Mark A.

2008-04-01

46

ENHANCED DETECTION AND ISOLATION OF THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS: CAUSAL AGENT OF DEEP BARK CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep bark canker (DBC) of walnut is caused by the bacterium Brenneria rubrifaciens which produces the red pigment rubrifacine. This disease of English walnut trees, is characterized by deep vertical cankers which exude sap laden with B. rubrifaciens. Although DBC is not observed on younger trees, ...

47

Figure 1. Rapidly wilting black walnut in the final stage of thousand cankers  

E-print Network

Figure 1. Rapidly wilting black walnut in the final stage of thousand cankers disease. Figure 2 1998. Pest Alert Walnut Twig Beetle and Thousand Cankers Disease of Black Walnut Within the past decade an unusual decline of black walnut (Juglans nigra) has been observed in several western states. Initial

48

BARK CANKER OF UNKNOWN ETIOLOGY DEVELOPING ON PECAN CARYA ILLINOENSIS TREES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pecan trees in a five-year-old orchard of 17 cultivars had symptoms of an unusual bark canker first noticed in October, 2002. Symptoms appeared from ground line up to 3 meters on the central leader and most likely were initiated during the summer of 2002. Cankers developed around buds of the trunk...

49

Characterization of Alternaria infectoria extracellular vesicles  

PubMed Central

Many fungi use membrane vesicles to transport complex molecules across their cell walls. Like mammalian exosomes, fungal vesicles contain lipids, proteins, and polysaccharides, many of which are associated with virulence. Here we identify and characterize extracellular vesicles (EVs) in Alternaria infectoria, a ubiquitous, environmental filamentous fungus that is also an opportunistic human pathogen. Examination of the A. infectoria EVs revealed a morphology similar to that of vesicles described in other fungal species. Of note, proteomic analysis detected a reduced number of vesicle-associated proteins. There were two prevalent categories among the 20 identified proteins, including the polysaccharide metabolism group, probably related to plant host invasion or biosynthesis/degradation of cell wall components, and the nuclear proteins, especially DNA repair enzymes. We also found enzymes related to pigment synthesis, adhesion to the host cell, and trafficking of vesicles/organelles/molecules. This is the first time EV secretions have been identified in a filamentous fungus. We believe that these vesicles might have a role in virulence. PMID:24576997

Silva, Branca M.A.; Prados-Rosales, Rafael; Espadas-Moreno, Javier; Wolf, Julie M.; Luque-Garcia, Jose L.; Gonçalves, Teresa; Casadevall, Arturo

2015-01-01

50

Allergic bronchopulmonary mycosis due to Alternaria: Case report and review.  

PubMed

While allergic bronchopulmonary aspergillosis and mycosis are well recognised, no cases have been described related to Alternaria spp. Alternaria is a common sensitising fungus in asthmatics and related to thunderstorm asthma. We report a case of an asthmatic who presented with worsening asthma control, mild eosinophilia on high dose inhaled corticosteroids (800 ?g/day), a total IgE of 3800 KIU/L, an Alternaria-specific IgE of 21.3 KUa/L and positive skin prick test, negative specific IgE and skin prick test to Aspergillus fumigatus, Penicillium spp., Cladosporium spp., Trichophyton spp. and a normal CT scan of the thorax. He responded well to a short course of oral prednisolone and then oral itraconazole, given over 17 months but relapsed 1 month after stopping it. PMID:24371728

Singh, Bhagteshwar; Denning, David W

2012-01-01

51

Toxigenic profile and AFLP variability of Alternaria alternata and Alternaria infectoria occurring on wheat  

PubMed Central

The objectives of this study were to evaluate the ability to produce alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) by A. alternata and A. infectoria strains recovered from wheat kernels obtained from one of the main production area in Argentina; to confirm using AFLPs molecular markers the identify of the isolates up to species level, and to evaluate the intra and inter-specific genetic diversity of these two Alternaria species. Among all the Alternaria strains tested (254), 84% of them were able to produce mycotoxins. The most frequent profile of toxin production found was the co-production of AOH and AME in both species tested. TA was only produced by strains of A. alternata. Amplified fragment polymorphism (AFLPs) analysis was applied to a set of 89 isolates of Alternaria spp (40 were A. infectoria and 49 were A. alternata) in order to confirm the morphological identification. The results showed that AFLPs are powerful diagnostic tool for differentiating between A. alternata and A. infectoria. Indeed, in the current study the outgroup strains, A. tenuissima was consistently classified. Characteristic polymorphic bands separated these two species regardless of the primer combination used. Related to intraspecific variability, A. alternata and A. infectoria isolates evaluated seemed to form and homogeneous group with a high degree of similarity among the isolates within each species. However, there was more scoreable polymorphism within A. alternata than within A. infectoria isolates. There was a concordance between morphological identification and separation up to species level using molecular markers. Clear polymorphism both within and between species showed that AFLP can be used to asses genetic variation in A. alternata and A. infectoria. The most important finding of the present study was the report on AOH and AME production by A. infectoria strains isolated from wheat kernels in Argentina on a semisynthetic media for the first time. Also, specific bands for A. alternata and A. infectoria have been identified; these may be useful for the design of specific PCR primers in order to differentiate these species and to detect them in cereals. PMID:24294236

Oviedo, María Silvina; Sturm, María Elena; Reynoso, María Marta; Chulze, Sofia Noemi; Ramirez, María Laura

2013-01-01

52

A Novel Alternaria Species Isolated from Peucedanum japonicum in Korea  

PubMed Central

We isolated and examined a new Alternaria sp., which causes leaf spots on Peucedanum japonicum in Korea, by using molecular and morphological methods. Phylogenetic analysis based on a combined internal transcribed spacer region analysis and two protein-coding genes (gpd and Alt a1) demonstrated that the causal fungus was most closely related to A. cinerariae and A. sonchi, and relevant to A. brassicae. However, conidial morphology indicated that it is a novel species within the genus Alternaria, and therefore we have assigned the fungus a new name in this study. PMID:24808728

Deng, Jian Xin; Cho, Hye Sun; Paul, Narayan Chandra; Lee, Hyang Burm

2014-01-01

53

Airborne fungal spores of Alternaria, meteorological parameters and predicting variables  

NASA Astrophysics Data System (ADS)

Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t - 1) and mean concentration of the same day or week in other years (C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t - 1, and meteorological parameters were included in the equation, the resulting R 2 satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R 2 varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t - 1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air.

Filali Ben Sidel, Farah; Bouziane, Hassan; del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

2014-05-01

54

Airborne fungal spores of Alternaria, meteorological parameters and predicting variables.  

PubMed

Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t?-?1) and mean concentration of the same day or week in other years (C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t?-?1, and meteorological parameters were included in the equation, the resulting R (2) satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R (2) varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t?-?1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air. PMID:24844880

Filali Ben Sidel, Farah; Bouziane, Hassan; Del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

2014-05-21

55

[Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng].  

PubMed

To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG. PMID:25282882

Chen, Chang-Qing; Li, Tong; Li, Xin-Lian; Jiang, Yun; Tian, Lei; Xu, Peng

2014-05-01

56

Comparison of enzyme immunoassay–based assays for environmental Alternaria alternata  

PubMed Central

Background Alternaria alternata–derived allergenic materials are causes of human disease. Several immunoassays exist to quantify these materials. Objective To compare methods for evaluating Alternaria content. Methods Four methods, including 1 monoclonal antibody (MAb)–based assay specific for recombinant Alt a 1, 1 MAb-based assay for chromatographically purified Alt a 1, 1 polyclonal antibody (PAb)–based assay for chromatographically purified Alt a 1, and 1 PAb-based assay for whole Alternaria extract, were evaluated. Environmental samples collected as part of the National Survey of Lead and Allergens in Housing were examined. Alternaria spore counts were determined in dust by observation. Results The MAb-based assay for recombinant Alt a 1 detected Alternaria in few samples (25%); the PAb-based assay for whole Alternaria proteins detected antigen in 97% of the samples. The PAb- and MAb-based assays for purified Alt a 1 detected antigen in 100% of the samples. There was a significant positive correlation between the 2 assays directed against purified Alt a 1. There was a positive correlation between the PAb-based assay for whole Alternaria and the PAb-based assay for Alt a 1. Nearly all the dust samples contained Alternaria spores, and there was a strong positive correlation between counts and all assays. Conclusion Because of the multifaceted nature of Alternaria, the disparities between methods for quantifying Alternaria, the cross-reactivity between fungal allergens, and the documented genetic promiscuity of this fungus, enzyme immunoassays using PAbs against a range of Alternaria proteins will probably produce the most reliable estimation of overall Alternaria exposure in house dust. PMID:17042141

Barnes, Charles; Portnoy, Jay; Sever, Michelle; Arbes, Samuel; Vaughn, Ben; Zeldin, Darryl C.

2007-01-01

57

Oak Tree Canker Disease Supports Arthropod Diversity in a Natural Ecosystem  

PubMed Central

Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

2014-01-01

58

Innate Type-2 Response to Alternaria Extract Enhances Ryegrass-induced Lung Inflammation  

PubMed Central

Background Exposure to the fungal allergen Alternaria alternata as well as ryegrass pollen has been implicated in severe asthma symptoms during thunderstorms. We have previously shown that Alternaria extract induces innate type 2 lung inflammation in mice. We hypothesized that the innate eosinophilic response to Alternaria extract may enhance lung inflammation induced by ryegrass. Methods Mice were sensitized to ryegrass allergen and administered a single challenge with Alternaria alternata extract before or after final ryegrass challenges. Levels of BAL eosinophils, neutrophils, Th2 cells, innate lymphoid cells (ILC2), IL-5 and IL-13 as well as inflammation and mucus were assessed. Results Mice receiving ryegrass sensitization and challenge developed an eosinophilic lung response. A single challenge with Alternaria extract given 3 days before or 3 days after ryegrass challenges resulted in increased eosinophils, peribronchial inflammation and mucus production in the airway compared with ryegrass only challenges. Type 2 innate lymphoid cell (ILC2) and Th2 cell recruitment to the airway was increased after Alternaria extract exposure in ryegrass challenged mice. Innate challenges with Alternaria extract induced BAL eosinophilia, Th2 cell recruitment as well as ILC2 expansion and proliferation. Conclusions A single exposure of Alternaria extract in ryegrass sensitized and challenged mice enhances the type-2 lung inflammatory response including airway eosinophilia, peribronchial infiltrate, and mucus production possibly through Th2 cell recruitment and ILC2 expansion. If translated to humans, exposures to both grass pollen and Alternaria may be a potential cause of thunderstorm-related asthma. PMID:24296722

Kim, Hee-Kyoo; Lund, Sean; Baum, Rachel; Rosenthal, Peter; Khorram, Naseem; Doherty, Taylor A.

2014-01-01

59

Antiproliferative, antifungal, and antibacterial activities of endophytic alternaria species from cupressaceae.  

PubMed

Recent research has shown the bioprospecting of endophytic fungi from Cupressaceae. Here, we further uncover that the healthy cypress plants such as Cupressus arizonica, Cupressus sempervirens var. cereiformis, and Thuja orientalis host highly bioactive endophytic Alternaria fungal species. Indeed, endophytic Alternaria alternata, Alternaria pellucida, and Alternaria tangelonis were recovered from healthy Cupressaceous trees. Biodiversity and bioactivity of recovered endophytic Alternaria species were a matter of biogeography and host identity. We further extracted such Alternaria's metabolites and highlighted their significant antiproliferative, growth inhibitory, and antibacterial activities against the model target fungus Pyricularia oryzae and the model pathogenic bacteria Bacillus sp., Erwinia amylovora, and Pseudomonas syringae. In vitro assays also indicated that endophytic Alternaria species significantly inhibited the growth of cypress fungal phytopathogens Diplodia seriata, Phaeobotryon cupressi, and Spencermartinsia viticola. In conclusion, since the recovered Alternaria species were originally reported as pathogenic and allergenic fungi, our findings suggest a possible ecological niche for them inside the foliar tissues of Cupressaceous trees. Moreover, in this study, the significant bioactivities of endophytic Alternaria species in association with Cupressaceae plant family are reported. PMID:24801337

Soltani, Jalal; Hosseyni Moghaddam, Mahdieh S

2014-09-01

60

REAL-TIME PCR DETECTION AND DEVELOPMENT OF A BIOASSAY FOR THE DEEP BARK CANKER PATHOGEN, BRENNARIA RUBRIFACIENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep Bark Canker (DBC), caused by the bacterium Brennaria rubrifaciens afflicts English walnut cultivars and is characterized by late onset of symptoms in trees greater than 15 years old. These symptoms include deep bleeding vertical cankers along the trunk and larger branches that exude a bacteria...

61

Deinococcus citri sp. nov., isolated from citrus leaf canker lesions.  

PubMed

A Gram-stain-positive, strictly aerobic, non-motile, coccoid bacterium, designated NCCP-154(T), was isolated from citrus leaf canker lesions and was subjected to a polyphasic taxonomic study. Strain NCCP-154(T) grew at 10-37 °C (optimum 30 °C) and at pH 7.0-8.0 (optimum pH 7.0). The novel strain exhibited tolerance of UV irradiation (>1000 J m(-2)). Based on 16S rRNA gene sequence analysis, strain NCCP-154(T) showed the highest similarity to Deinococcus gobiensis CGMCC 1.7299(T) (98.8?%), and less than 94?% similarity to other closely related taxa. The chemotaxonomic data [major menaquinone, MK-8; cell-wall peptidoglycan type, A3? (Orn-Gly2); major fatty acids, summed feature 3 (C16?:?1?7c/iso-C15?:?0 2-OH; 35.3?%) followed by C16?:?0 (12.7?%), iso-C17?:?1?9c (9.2?%), C17?:?1?8c (7.4?%) and iso-C17?:?0 (6.9?%); major polar lipids made up of several unidentified phosphoglycolipids and glycolipids and an aminophospholipid, and mannose as the predominant whole-cell sugar] also supported the affiliation of strain NCCP-154(T) to the genus Deinococcus. The level of DNA-DNA relatedness between strain NCCP-154(T) and D. gobiensis JCM 16679(T) was 63.3±3.7?%. The DNA G+C content of strain NCCP-154(T) was 70.0 mol%. Based on the phylogenetic analyses, DNA-DNA hybridization and physiological and biochemical characteristics, strain NCCP-154(T) can be differentiated from species with validly published names. Therefore, it represents a novel species of the genus Deinococcus. The name Deinococcus citri sp. nov. is proposed, with the type strain NCCP-154(T) (?=?JCM 19024(T)?=?DSM 24791(T)?=?KCTC 13793(T)). PMID:25256704

Ahmed, Iftikhar; Abbas, Saira; Kudo, Takuji; Iqbal, Muhammad; Fujiwara, Toru; Ohkuma, Moriya

2014-12-01

62

Two new compounds from an endophytic fungus Alternaria solani.  

PubMed

Two new secondary metabolites, named 7-dehydroxyl-zinniol (1) and 20-hydroxyl-ergosta-4,6,8(14),22-tetraen-3-one (2), were isolated from the culture of Alternaria solani, an endophytic fungal strain residing in the roots of Aconitum transsectum. Their structures were elucidated on the basis of comprehensive spectroscopic analyses including IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR. Biological activity tests indicated that compound 1 showed moderate anti-HBV activity. PMID:23106531

Ai, Hong-Lian; Zhang, Li-Mei; Chen, Yan-Ping; Zi, Shu-Hui; Xiang, Hong; Zhao, Da-Ke; Shen, Yong

2012-01-01

63

GENETIC DIVERSITY AND WORLDWIDE PROLIFERATION OF CITRUS BACTERIAL CANKER PATHOGENS IDENTIFIED IN HIRTORIC SPECIMENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) may have originated in Southeast Asia based on symptoms present on early herbarium specimens. The disease was first introduced into the United States in 1911 and has spread to most citrus producing areas in the world. Thi...

64

GENETIC DIVERSITY AND WORLDWIDE PROLIFERATION OF CITRUS BACTERIAL CANKER PATHOGENS IDENTIFIED IN HISTORIC SPECIMENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) may have originated in Southeast Asia, based on symptoms present on early herbarium specimens. The disease was first introduced into the United States in 1911 and has spread to most citrus producing areas in the world. Th...

65

Hyperspectral reflectance imaging for detecting citrus canker based on dual-band ratio image classification method  

Microsoft Academic Search

Citrus are one of the major fruit produced in China. Most of this production is exported to Europe for fresh consumption, where consumers increasingly demand best quality. Citrus canker is one of the most devastating diseases that threaten peel of most commercial citrus varieties. The aim of this research was to investigate the potential of using hyperspectral imaging technique for

Jiangbo Li; Xiuqin Rao; Junxian Guo; Yibin Ying

2010-01-01

66

REPEATABILITY AND COMPARISION OF IMAGE ANALYSIS AND VISUAL ASSESSMENT FOR DISEASE ASSESSMENT OF CITRUS CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker, a disease of several citrus species, is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). The disease is of concern in several wet tropical and subtropical citrus growing regions as infection results in yield loss and severely blemished fruit unsuitable for the f...

67

DETECTION OF BRENNARIA RUBRIFACIENS THE CAUSATIVE AGENT OF DEEP BARK CANKER (DBC)OF WALNUT  

Technology Transfer Automated Retrieval System (TEKTRAN)

DBC afflicts English walnut cultivars and is characterized by late onset in trees greater than 15 years old. Symptoms include deep bleeding vertical cankers that exude a bacterial-laden reddish brown sap. We have developed a robust PCR-based technique to detect B. rubrifaciens in soil and symptomles...

68

Canker and twig dieback of blueberry caused by Pestalotiopsis spp. and a Truncatella sp. in Chile  

Technology Transfer Automated Retrieval System (TEKTRAN)

Blueberry (Vaccinium spp.) has great economic importance in Chile, currently with about 8,500 ha being cultivated. Recently, the presence of canker and dieback symptoms has been observed along the productive blueberry zone of Chile extending from the V Region (32º49´ South lat.) in the north to the ...

69

Update on packing line protocols for citrus canker and their effects on bacterial survival  

Technology Transfer Automated Retrieval System (TEKTRAN)

Markets for Florida citrus are severely restricted by regulations in place to minimize the spread of citrus canker to citrus producing areas. Included in these regulations are accepted protocols for sanitation and coating of fruit. However, these measures do not eradicate all the living bacterial ce...

70

Enhanced tomato resistance to bacterial canker by application of turtle oil  

Microsoft Academic Search

Pretreatment with oil of sea turtle Caretta caretta protected tomato plants against bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm). The turtle oil was ineffective in inhibiting Cmm in an agar diffusion test, suggesting a mechanism of induced resistance. Under controlled conditions in the greenhouse, turtle oil lowered the disease index and had reduced the growth of bacteria up

Ömür Baysal; Y. Ziya Gürsoy; Hakan Örnek; Ahmet Duru

2005-01-01

71

Endophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native Myrtaceae  

E-print Network

regarding the occurrence and species diversity of Botryosphaeriaceae in native Myrtaceae forests or what. nov. are novel species found only on native myrtaceous hosts. Pathogenicity tests showed that isolatesEndophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native

72

IMAGE ANALYSIS VERSUS VISUAL ASSESSMENT OF INCIDENCE AND SEVERITY OF CITRUS CANKER SYMPTOMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Xanthomonas axonopodis pv citri causes citrus canker. Disease assessment is important for monitoring epidemics. Visual assessment (VA) is presently the only reliable means of detection. To investigate how VA of symptoms compared to image analysis we used digital images of 214 citrus le...

73

ANNUAL AND POLYETIC PROGRESSION OF CITRUS CANKER ON TREES PROTECTED WITH COPPER SPRAYS  

Technology Transfer Automated Retrieval System (TEKTRAN)

: Mathematical models are important tools for comparative analysis of epidemics. In this paper, parameters obtained from the mathematical model that best fitted to the annual progress curves of citrus canker incidence were used to evaluate the effect of copper sprays and windbreaks on the annual and...

74

Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease  

Microsoft Academic Search

Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector

Y. Hu; J. Zhang; H. Jia; D. Sosso; T. Li; W. B. Frommer; B. Yang; F. F. White; N. Wang; J. B. Jones

2014-01-01

75

Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) was first documented in India and Java in the mid 19th century. Since that time the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described str...

76

THE EFFECT OF HURRICANES AND TROPICAL STORMS ON LONG DISTANCE SPREAD OF CITRUS CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) is a serious disease of citrus that causes foliar and fruit lesions leading to extensive yield and quality losses. During Fall 2004, Florida experienced 3 hurricanes (Charlie, Francis, Jeanne) and one tropical storm (Ivan) whose paths crossed the majority of the commercia...

77

LONG DISTANCE SPREAD OF CITRUS CANKER RELATED TO HURRICANES AND TROPICAL STORMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) is a serious disease of citrus that causes foliar and fruit lesions leading to extensive yield and quality losses. During Fall 2004, Florida experienced 3 hurricanes (Charlie, Francis, Jeanne) and one tropical storm (Ivan) whose paths crossed the majority of the commercia...

78

Citrus MAF1, a Repressor of RNA Polymerase III, Binds the Xanthomonas citri Canker Elicitor PthA4 and Suppresses Citrus Canker Development1  

PubMed Central

Transcription activator-like (TAL) effectors from Xanthomonas species pathogens act as transcription factors in plant cells; however, how TAL effectors activate host transcription is unknown. We found previously that TAL effectors of the citrus canker pathogen Xanthomonas citri, known as PthAs, bind the carboxyl-terminal domain of the sweet orange (Citrus sinensis) RNA polymerase II (Pol II) and inhibit the activity of CsCYP, a cyclophilin associated with the carboxyl-terminal domain of the citrus RNA Pol II that functions as a negative regulator of cell growth. Here, we show that PthA4 specifically interacted with the sweet orange MAF1 (CsMAF1) protein, an RNA polymerase III (Pol III) repressor that controls ribosome biogenesis and cell growth in yeast (Saccharomyces cerevisiae) and human. CsMAF1 bound the human RNA Pol III and rescued the yeast maf1 mutant by repressing tRNAHis transcription. The expression of PthA4 in the maf1 mutant slightly restored tRNAHis synthesis, indicating that PthA4 counteracts CsMAF1 activity. In addition, we show that sweet orange RNA interference plants with reduced CsMAF1 levels displayed a dramatic increase in tRNA transcription and a marked phenotype of cell proliferation during canker formation. Conversely, CsMAF1 overexpression was detrimental to seedling growth, inhibited tRNA synthesis, and attenuated canker development. Furthermore, we found that PthA4 is required to elicit cankers in sweet orange leaves and that depletion of CsMAF1 in X. citri-infected tissues correlates with the development of hyperplastic lesions and the presence of PthA4. Considering that CsMAF1 and CsCYP function as canker suppressors in sweet orange, our data indicate that TAL effectors from X. citri target negative regulators of RNA Pol II and Pol III to coordinately increase the transcription of host genes involved in ribosome biogenesis and cell proliferation. PMID:23898043

Soprano, Adriana Santos; Abe, Valeria Yukari; Smetana, Juliana Helena Costa; Benedetti, Celso Eduardo

2013-01-01

79

Fungal meningoencephalitis caused by Alternaria: a clinical case.  

PubMed

Cerebral phaeohyphomycosis is an infrequent infectious condition associated with a high mortality rate. The authors describe a very rare case that occurred in an immunocompetent 18-year-old man who developed severe meningoencephalitis and arachnoiditis caused by Alternaria alternata, which were diagnosed in the context of difficult-to-treat hydrocephalus. Etiological diagnosis was made based on fungal culture and histopathologic examination. Empirical treatment consisted of an early aggressive antifungal combination therapy consisting of intravenous liposomal amphotericin B (5 mg/kg per day) and voriconazole (4 mg/kg every 12 h), which initially induced a favorable response. Following the fungus identification, the choice for the combination of posaconazole (400 mg every 12 h) plus flucytosine (4000 mg/day) proved to be effective in the suppression of the signs and symptoms of this uncommon cerebral mycosis. At a 12-month follow-up visit no recurrence had occurred and posaconazole was then stopped. PMID:23381981

Silveira, Cícero J C; Amaral, Joana; Gorayeb, Rodrigo P; Cabral, José; Pacheco, Teresa

2013-02-01

80

Alternaria-derived serine protease activity drives IL-33–mediated asthma exacerbations  

PubMed Central

Background The fungal allergen Alternaria alternata is implicated in severe asthma and rapid onset life-threatening exacerbations of disease. However, the mechanisms that underlie this severe pathogenicity remain unclear. Objective We sought to investigate the mechanism whereby Alternaria was capable of initiating severe, rapid onset allergic inflammation. Methods IL-33 levels were quantified in wild-type and ST2?/? mice that lacked the IL-33 receptor given inhaled house dust mite, cat dander, or Alternaria, and the effect of inhibiting allergen-specific protease activities on IL-33 levels was assessed. An exacerbation model of allergic airway disease was established whereby mice were sensitized with house dust mite before subsequently being challenged with Alternaria (with or without serine protease activity), and inflammation, remodeling, and lung function assessed 24 hours later. Results Alternaria, but not other common aeroallergens, possessed intrinsic serine protease activity that elicited the rapid release of IL-33 into the airways of mice through a mechanism that was dependent upon the activation of protease activated receptor-2 and adenosine triphosphate signaling. The unique capacity of Alternaria to drive this early IL-33 release resulted in a greater pulmonary inflammation by 24 hours after challenge relative to the common aeroallergen house dust mite. Furthermore, this Alternaria serine protease–IL-33 axis triggered a rapid, augmented inflammation, mucus release, and loss of lung function in our exacerbation model. Conclusion Alternaria-specific serine protease activity causes rapid IL-33 release, which underlies the development of a robust TH2 inflammation and exacerbation of allergic airway disease. PMID:24636086

Snelgrove, Robert J.; Gregory, Lisa G.; Peiró, Teresa; Akthar, Samia; Campbell, Gaynor A.; Walker, Simone A.; Lloyd, Clare M.

2014-01-01

81

The effect of runoff on spray deposition and control of Alternaria brown spot of mandarins  

Microsoft Academic Search

Alternaria alternata pv. citri is the causal agent of Alternaria brown spot on tangerines and their hybrids and infects young leaves and fruit of all ages.\\u000a In South Africa, repeated high volume (?9000 L\\/ha) fungicide sprays on susceptible cultivars are the only effective control\\u000a measure of this disease. The effect of runoff on spray deposition and biological efficacy was largely

P. H. Fourie; M. du Preez; J. C. Brink; G. C. Schutte

2009-01-01

82

Barrier disrupting effects of alternaria alternata extract on bronchial epithelium from asthmatic donors.  

PubMed

Sensitization and exposure to the allergenic fungus Alternaria alternata has been associated with increased risk of asthma and asthma exacerbations. The first cells to encounter inhaled allergens are epithelial cells at the airway mucosal surface. Epithelial barrier function has previously been reported to be defective in asthma. This study investigated the contribution of proteases from Alternaria alternata on epithelial barrier function and inflammatory responses and compared responses of in vitro cultures of differentiated bronchial epithelial cells derived from severely asthmatic donors with those from non-asthmatic controls. Polarised 16HBE cells or air-liquid interface (ALI) bronchial epithelial cultures from non-asthmatic or severe asthmatic donors were challenged apically with extracts of Alternaria and changes in inflammatory cytokine release and transepithelial electrical resistance (TER) were measured. Protease activity in Alternaria extracts was characterised and the effect of selectively inhibiting protease activity on epithelial responses was examined using protease inhibitors and heat-treatment. In 16HBE cells, Alternaria extracts stimulated release of IL-8 and TNF?, with concomitant reduction in TER; these effects were prevented by heat-treatment of the extracts. Examination of the effects of protease inhibitors suggested that serine proteases were the predominant class of proteases mediating these effects. ALI cultures from asthmatic donors exhibited a reduced IL-8 response to Alternaria relative to those from healthy controls, while neither responded with increased thymic stromal lymphopoietin (TSLP) release. Only cultures from asthmatic donors were susceptible to the barrier-weakening effects of Alternaria. Therefore, the bronchial epithelium of severely asthmatic individuals may be more susceptible to the deleterious effects of Alternaria. PMID:24009658

Leino, Marina S; Loxham, Matthew; Blume, Cornelia; Swindle, Emily J; Jayasekera, Nivenka P; Dennison, Patrick W; Shamji, Betty W H; Edwards, Matthew J; Holgate, Stephen T; Howarth, Peter H; Davies, Donna E

2013-01-01

83

STAT6 regulates natural helper cell proliferation during lung inflammation initiated by Alternaria  

PubMed Central

Asthma exacerbations can be caused by a number of factors, including the fungal allergen Alternaria, which is specifically associated with severe and near-fatal attacks. The mechanisms that trigger lung responses are unclear and might vary between allergens. A comparison between Alternaria, Aspergillus, Candida, and house dust mite, all allergens in humans, showed that only Alternaria promoted immediate innate airway eosinophilia within 12 h of inhalation in nonsensitized mice. Alternaria, but not the other allergens, induced a rapid increase in airway levels of IL-33, accompanied by IL-33 receptor (IL-33R)-positive natural helper cell (NHC) production of IL-5 and IL-13. NHCs in the lung and bone marrow constitutively expressed transcription factors [GATA-3 and E26 transformation-specific sequence-1 (ETS-1)] that could allow for rapid induction of T helper type 2 (Th2) cytokines. Lung NHC numbers and proliferation (%Ki-67), but not IL-5 or GATA-3 expression, were significantly reduced in STAT6-deficient mice 3 days after one challenge with Alternaria. Alternaria induced NHC expression of the EGF receptor ligand amphiregulin (partially dependent on STAT6), as well as EGF receptor signaling in the airway epithelium. Finally, human peripheral blood NHCs (CRTH2+CD127+ lineage-negative lymphocytes) from allergic individuals highly expressed GATA-3 and ETS-1, similar to lung NHCs in mice. In summary, Alternaria-induced lung NHC proliferation and expression of amphiregulin are regulated by STAT6. In addition, NHCs in mouse and humans are primed to express Th2 cytokines through constitutive expression of GATA-3 and ETS-1. Thus several transcription factor pathways (STAT6, GATA-3, and ETS-1) may contribute to NHC proliferation and Th2-type responses in Alternaria-induced asthma. PMID:22865552

Khorram, Naseem; Chang, Jinny E.; Kim, Hee-Kyoo; Rosenthal, Peter; Croft, Michael; Broide, David H.

2012-01-01

84

A technique for screening muskmelon seedlings for resistance to Alternaria cucumerina  

E-print Network

in dried tissue (6, 27). The primary spring inoculum comes from renewed growth of the mycelium in host debris (19). The conidia are important in the dissemination of the pathogen during the growing season (18). In 1892, the causal organism of leafspot... symptoms of Alternaria leafspot caused by Alternaria cucumerina on 16 wk old leaves of Perlita muskmelons. Figure 2. (A, B) Disease screening room consisting of (A) illuminated growth bench, (B) incubation chambers. (C) Inoculation of muskmelon...

Carmody, Beth Elaine

2012-06-07

85

First report of stem canker of Salsola tragus caused by Diaporthe eres in Russia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Salsola tragus L. (Russian thistle, tumbleweed), family Chenopodiaceae, is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying Salsola tragus plants were found along the Azov Sea at Chushka, Russia. About 30 plants in the...

86

Identification and characterization of microsatellite from Alternaria brassicicola to assess cross-species transferability and utility as a diagnostic marker.  

PubMed

Alternaria blight caused by Alternaria brassicicola (Schwein.) Wiltshire and A. brassicae (Berk.) Sacc., is one of the most important disease of rapeseed-mustard, characterized by the formation of spots on leaves, stem, and siliquae with premature defoliation and stunting of growth. These two species are very difficult to differentiate based on disease symptoms or spore morphology. Therefore, the aim of present investigation was to identify and characterize transferable microsatellite loci from A. brassicicola to A. brassicae for the development of diagnostic marker. A total of 8,457 microsatellites were identified from transcript sequences of A. brassicicola. The average density of microsatellites was one microsatellite per 1.94 kb of transcript sequence screened. The most frequent repeat was tri-nucleotide (74.03 %), whereas penta-nucleotide (1.14 %) was least frequent. Among amino acids, arginine (13.11 %) showed maximum abundance followed by lysine (10.11 %). A total of 32 alleles were obtained across the 31 microsatellite loci for the ten isolates of A. brassicicola. In cross-species amplifications, 5 of the 31 markers amplified the corresponding microsatellite regions in twenty isolates of A. brassicae and showed monomorphic banding pattern. Microsatellite locus ABS28 was highly specific for A. brassicicola, as no amplification was observed from twenty-nine other closely related taxa. Primer set, ABS28F/ABS28R, amplified a specific amplicon of 380 bp from all A. brassicicola isolates. Standard curves were generated for A. brassicicola isolate using SYBR Green I fluorescent dye for detection of amplification in real-time PCR assay. The lowest detection limit of assay was 0.01 ng. Thus, the primer set can be used as diagnostic marker to discriminate and diagnose A. brassicicola from synchronously occurring fungus, A. brassicae associated with rapeseed and mustard. PMID:25048820

Singh, Ruchi; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok Kumar; Mishra, Sanjay; Sharma, Arun Kumar

2014-11-01

87

Treponemes-Infected Canker in a Japanese Racehorse: Efficacy of Maggot Debridement Therapy  

PubMed Central

A 3-year-old thoroughbred colt presented with canker on its left hind foot. Subsequent development of cottage cheese-like horns and dermatitis disturbed healing, despite the use of miscellaneous orthodox treatment approaches to the lesions. Histological examination revealed exudative and suppurative dermatitis, and proliferatively suppurative epidermitis infected with helically coiled treponemes. Total debridement under general anesthesia led to a temporary improvement, but the ground surface regenerated abnormal epidermis similar to that observed initially after surgery. Maggot debridement therapy (MDT) was attempted, which removed all the abnormal tissue. After MDT, general farriery trimming helped to correct the distorted ground surface, and the horse returned to constant training and eventually raced. This case shows that MDT was successfully used for treatment of an intractable and treponemes-infected canker. PMID:24833994

KUWANO, Atsutoshi; NIWA, Hidekazu; HIGUCHI, Tohru; MITSUI, Hideya; AGNE, Robert A.

2012-01-01

88

Dustborne Alternaria alternata antigens in U.S. homes: Results from the National Survey of Lead and Allergens in Housing  

PubMed Central

Background: Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized. Objective: The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in U.S. homes. Methods: Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the U.S. completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of Alternaria antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay. Results: Alternaria antigens were detected in most (95-99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 ?g/g (SE=0.13 ?g/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of dehumidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes. Conclusion: Exposure to Alternaria alternata antigens in U.S. homes is common. Antigen levels in homes are not only influenced by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors. PMID:16159634

Salo, Päivi M.; Yin, Ming; Arbes, Samuel J.; Cohn, Richard D.; Sever, Michelle; Muilenberg, Michael; Burge, Harriet A.; London, Stephanie J.; Zeldin, Darryl C.

2005-01-01

89

Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat.  

PubMed

Alternaria species have the ability to produce a variety of secondary metabolite, which plays important roles in food safety. Argentina is the second largest exporter of fresh and processed food products to Europe, however, few studies on Alternaria mycotoxins and other bioactive secondary metabolites have been carried out on Argentinean cereals, fruit and vegetables. Knowing the full chemical potential and the distribution of Alternaria spp. on crops, it is necessary to establish a toxicological risk assessment for food products for human consumption. In the present study, 87 Alternaria strains from different substrates (tomato, wheat, blueberries and walnuts) were characterized according to morphology and metabolite production. Aggressive dereplication (accurate mass, isotopic patterns and lists of all described compounds from Alternaria) was used for high-throughput evaluation of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of "M" according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging to morphological groups "G" and "H". The cluster analysis yielded 16 almost identical dendrograms and grouped the Alternaria strains into four clusters and 11 singletons and outlier groups. The chemical analysis showed that AOH and AME were the most common metabolites produced, followed by TEN, ALXs and TeA. The A. infectoria sp.-grp. had no metabolites in common with the rest of the strains. Several secondary metabolites isolated from large-spored Alternaria species or other fungal genera were detected, such as dehydrocurvularin, pyrenochaetic acid and alternarienonic acid. The strains isolated from tomato produced lower amounts of metabolites than strains from blueberries, walnut and wheat, although individual strains from tomato produced the highest amount of some metabolites. The A. infectoria sp.-grp. was unique to cereals, whereas strains classified as belonging to the A. arborescens sp.-grp or having sporulation pattern "M" were only isolated from tomatoes. Otherwise, no clear association between substrate and identity could be found. The analyses in the study show that at least 75% of the Argentinean strains are able to produce potential mycotoxins. PMID:25498470

Andersen, Birgitte; Nielsen, Kristian F; Fernández Pinto, Virginia; Patriarca, Andrea

2015-03-01

90

Pilot-Plant Production of Protease by Alternaria tenuissima  

PubMed Central

Agar slants of a selected Alternaria tenuissima strain were illuminated to give conidia suitable for further propagation. For production of protease with an optimal caseolytic activity in the region of pH 8 to 10, the fungus was cultivated in steel fermentors with 6- and 60-liter working capacity. Maximal activity, 1.5 enzyme units per liter, was attained in a medium based on liver after about 60 hr of cultivation. The protease was secreted parallel with, or slightly after, the main growth phase. The process could be run favorably with a relatively low aeration rate. The pH of the culture decreased during the process from 7.0 to about 6.3. This was the optimal region also when pH was kept constant by automatic pH control. Optimal temperature was about 28 C, which resulted in a maximal productivity of 0.057 enzyme units per liter per hr during the protease secretion phase. Replacement of the liver in the medium with skim milk, meat scrap, or rapeseed oil meal resulted in a decrease of the protease yield. Images Fig. 1 Fig. 2 Fig. 5 PMID:6067633

Jönsson, Arne G.

1967-01-01

91

Bioactive metabolites from the endophytic fungus Alternaria alternata.  

PubMed

Two altenuene derivatives (1-2) and one isocoumarin (3), together with six known compounds (4-9) were isolated from solid cultures of an endophytic fungus Alternaria alternata, obtained from the fresh branches of Camellia sinensis. Chiral analysis revealed the racemic nature of 1 and 2, which were subsequently resolved into two pairs of enantiomers [(+)-1 and (-)-1, (+)-2 and (-)-2]. Structures of all the isolates were identified through spectroscopic data. Absolute configurations of the two pairs of enantiomers were determined by electronic circular dichroism (ECD) calculation and the chiral center of C-10 in 3 was deduced via [Rh2(OCOCF3)4]-induced CD experiment. All the isolates were evaluated for their antimicrobial abilities against the pathogenic bacteria and fungi as well as cytotoxic activities against two human tumor cell lines. Compound 5 was the most active against Bacillus subtilis with MIC80 of 8.6?g/ml, and compounds 1-3, 6-7 and 9 exhibited moderate to weak inhibition towards the test pathogenic microorganism. Compound 4 showed mild cytotoxic activity against human osteosarcoma cells U2OS with IC50 of 28.3?M. PMID:25261763

Wang, Ying; Yang, Ming-Hua; Wang, Xiao-Bing; Li, Tian-Xiao; Kong, Ling-Yi

2014-12-01

92

Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.  

PubMed

Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. PMID:25560914

Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

2015-03-16

93

The decline in quantity of bacteria of Xanthomonas axonopodis pv citri dispersed from canker-infected citrus plants during wind/rain events  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background and objectives. Citrus canker (caused by Xanthomonas axonopodis pv. citri, Xac) is an important disease of citrus in several tropical and sub-tropical citrus growing regions. Canker damaged trees produce less yield and the blemished fruit is unfit for fresh sale, so processing becomes the...

94

DEVELOPMENT OF A PCR-BASED METHOD FOR THE DETECTION OF BRENNARIA RUBRIFACIENS; THE CAUSAL AGENT OF DEEP BARK CANKER OF WALNUT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep Bark Canker (DBC), caused by the bacterium Brenneria rubrifaciens (previously known as Erwinia rubrifaciens), afflicts English walnut cultivars and is characterized by late onset of symptoms in trees greater than 15 years old. These symptoms include deep bleeding vertical cankers throughout th...

95

Isolation and characterization of the grain mold fungi, Cochliobolus and Alternaria spp., from sorghum using semi-selective media and DNA sequence analyses  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mold diseases, caused by fungal complexes including Alternaria, Cochliobolus and Fusarium species, limit sorghum grain production. Media were tested by plating Fusarium thapsinum, Alternaria sp. and Curvularia lunata, individually and competitively. Dichloran chloramphenicol rose bengal (DRBC) and m...

96

Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina.  

PubMed

A mycological survey was carried out at Entre Ríos province, Argentina, on sorghum grain, maize, rice, soybean seeds and on freshly harvested and stored wheat. The isolation frequencies and relative densities of species belonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and other fungi were calculated. Alternaria alternata was the major fungal species isolated from sorghum, rice, soybean seeds and on freshly harvested wheat, and a low incidence of Fusarium species was observed on the same substrates. In maize the major fungal species isolated was Fusarium verticillioides. The high incidence levels of A. alternata observed,suggest that it may be necessary to determine, among other mycotoxins, if Alternaria toxins occur in these commodities. PMID:17592893

Broggi, Leticia Elvira; González, Héctor Horacio Lucas; Resnik, Silvia Liliana; Pacin, Ana

2007-03-01

97

Effect of Lime on Criconemella xenoplax and Bacterial Canker in Two California Orchards  

PubMed Central

In a peach orchard with an initial soil pH of 4.9, preplant application of 0, 13.2, 18.2, 27.3, or 54.2 kg lime/tree site altered soil pH (range after 1 year = 4.8-7.3) but did not affect numbers of Criconemella xenoplax or tree circumference. Liming also failed to reduce the incidence of bacterial canker, which affected 17% of the trees by the sixth year after planting. Four years after planting, numbers of C. xenoplax exceeded 400/100 cm³ soil, regardless of treatment. Trees with higher densities of C. xenoplax had a higher incidence of canker. The nematophagous fungus Hirsutella rhossiliensis was not detected until the fourth year. Thereafter, the incidence of H. rhossiliensis and percentage C. xenoplax parasitized by H. rhossiliensis increased, but the increases lagged behind increases in numbers of nematodes. In an almond orchard with an initial soil pH of 4.6, preplant application of 0, 6.4, 12.8, or 25.0 kg lime/tree site altered soil pH (range after 1 year = 4.7-7.1). Numbers of C. xenoplax remained low (<20/100 cm³ soil), whereas numbers of Paratylenchus sp. increased to high levels (>500/100 cm³ soil), regardless of treatment. Low levels (<20/100 cm³ soil) of H. rhossiliensis -parasitized Paratylenchus sp. were detected. No bacterial canker occurred, but tree circumference was greater after 6 years if soil pH was intermediate (6.0-7.0). PMID:19279934

Underwood, T.; Jaffee, B. A.; Verdegaal, P.; Norton, M. V. K.; Asai, W. K.; Muldoon, A. E.; McKenry, M. V.; Ferris, H.

1994-01-01

98

Amplification of DNA of Xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.  

PubMed

Herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. The appearance of novel strains of the pathogen in Florida and elsewhere make it increasingly important to understand the relationships among strains of this pathogen. USDA-ARS at Beltsville, Maryland maintains approximately 700 herbarium specimens with citrus canker disease lesions up to 90 years old, originally collected from all over the world, and so is an important resource for phytogeographic studies of this bacterium. Unfortunately, DNA in herbarium specimens is degraded and may contain high levels of inhibitors of PCR. In this study, we compared a total of 23 DNA isolation techniques in combination with 31 novel primer pairs in order to develop an efficient protocol for the analysis of Xac DNA in herbarium specimens. We identified the most reliable extraction method, identified in terms of successful amplification by our panel of 31 primer pairs. We also identified the most robust primer pairs, identified as successful in the largest number of extracts prepared by different methods. We amplified Xac genomic sequences up to 542 bp long from herbarium samples up to 89 years old. Primers varied in effectiveness, with some primer pairs amplifying Xac DNA from a 1/10,000 dilution of extract from a single lesion from a citrus canker herbarium specimen. Our methodology will be useful to identify pathogens and perform molecular analyses of bacterial and possibly fungal genomes from herbarium specimens. PMID:16099061

Li, Wenbin; Brlansky, Ronald H; Hartung, John S

2006-05-01

99

Characterization and Pathogenicity of Alternaria vanuatuensis, a New Record from Allium Plants in Korea and China  

PubMed Central

Alternaria from different Allium plants was characterized by multilocus sequence analysis. Based on sequences of the ?-tubulin (BT2b), the Alternaria allergen a1 (Alt a1), and the RNA polymerase II second largest subunit (RPB2) genes and phylogenetic data analysis, isolates were divided into two groups. The two groups were identical to representative isolates of A. porri (EGS48-147) and A. vanuatuensis (EGS45-018). The conidial characteristics and pathogenicity of A. vanuatuensis also well supported the molecular characteristics. This is the first record of A. vanuatuensis E. G. Simmons & C. F. Hill from Korea and China. PMID:25606017

Li, Mei Jia; Deng, Jian Xin; Paul, Narayan Chandra

2014-01-01

100

STEM, STEM Education, STEMmania  

ERIC Educational Resources Information Center

In this article, the author introduces integrative STEM (science, technology, engineering, and/or mathematics) education and discusses the importance of the program. The notion of integrative STEM education includes approaches that explore teaching and learning between/among any two or more of the STEM subject areas, and/or between a STEM subject…

Sanders, Mark

2009-01-01

101

Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi.  

PubMed

Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, altertoxins V (1) and VI (2) together with the known compounds, altertoxins I (3), II (4), and III (5). The structures of 1 and 2 were determined by detailed spectroscopic analysis and those of 3-5 were established by comparison with reported data. When tested in our cell-based assay at concentrations insignificantly toxic to T-cells, altertoxins V (1), I (3), II (4), and III (5) completely inhibited replication of the HIV-1 virus at concentrations of 0.50, 2.20, 0.30, and 1.50 ?M, respectively. Our findings suggest that the epoxyperylene structural scaffold in altertoxins may be manipulated to produce potent anti-HIV therapeutics. PMID:25260957

Bashyal, Bharat P; Wellensiek, Brian P; Ramakrishnan, Rajesh; Faeth, Stanley H; Ahmad, Nafees; Gunatilaka, A A Leslie

2014-11-01

102

Reclassification of the butternut canker fungus, Sirococcus clavigignenti-juglandacearum, into the genus Ophiognomonia.  

PubMed

Sirococcus clavigignenti-juglandacearum (Sc-j), which causes a canker disease on butternut, is largely responsible for the decline of this tree in the United States and Canada. The original description of the species was based on anamorphic characters because the teleomorph is unknown. Recent phylogenetic investigations have found that Sc-j is not a member of the genus Sirococcus, and accurate taxonomic classification is required. The objective of this study is to use sequence data to determine the phylogenetic placement of Sc-j within the Gnomoniaceae, Diaporthales. Isolates were recovered from infected Juglans ailantifolia var. cordiformis (heartnut), Juglans cinerea (butternut), and Juglans nigra (black walnut) in Ontario and the eastern United States. The genes coding for ?-tubulin, actin, calmodulin, internal transcribed spacers 1 and 2, and the translation elongation factor 1-alpha from 28 isolates of Sc-j and representatives of the major lineages within the Gnomoniaceae were evaluated. There was no difference in the sequences of the five genes among the isolates of Sc-j studied, indicating a recent introduction followed by asexual reproduction and spread via conidia. The phylogenetic analyses demonstrate this fungus does not belong to the genus Sirococcus, and provides strong support (99% MP and 100% NJ bootstrap values, and 100% Bayesian posterior probabilities) for its inclusion in the genus Ophiognomonia, thereby supporting a reclassification of the butternut canker fungus to Ophiognomonia clavigignenti-juglandacearum. PMID:21215957

Broders, K D; Boland, G J

2011-01-01

103

Under severe HLB and citrus canker pressure, 'Triumph' and 'Jackson' perform better than 'Flame' and 'Marsh' grapefruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

Huanglongbing (HLB) and Citrus Canker (CC) threaten the viability of Florida grapefruit production. ‘Triumph’ (T), reportedly a grapefruit/sweet orange hybrid, is similar to seedy white grapefruit with earlier maturity and lower bitterness. ‘Jackson’ (J) is a low-seeded budsport of ‘Triumph’. Tree h...

104

Characteristics of the perception of different severity measures of citrus canker and the relations between the various symptom types  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is a disease of citrus and is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). Ways of managing the disease are being sought, and accurate, precise, reproducible disease assessment is needed for monitoring epidemics. The objective of this study was to investigate...

105

Effect of the duration of inoculum exposure on development of citrus canker symptoms on seedlings of Swingle citrumelo  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is one of the most serious diseases citrus in Florida, and elsewhere in the world. The disease causes yield loss and some fresh fruit trade restrictions may apply. Cultural management techniques such as windbreaks may work by not only reducing wind...

106

THE EFFECT OF WIND SPEED ON THE DISPERSAL PLUME OF BACTERIA DOWNWIND FROM CANKER-INFECTED GRAPEFRUIT TREES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Xanthomonas axonopodis pv citri causes citrus canker. Disease assessment is important for monitoring epidemics. Visual assessment (VA) is presently the only reliable means of detection. To investigate how VA of symptoms compared to image analysis we used digital images of 214 citrus le...

107

Visual rating and the use of image analysis for assessing different symptoms of citrus canker on grapefruit leaves  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac) and infects several citrus species in wet tropical and subtropical citrus growing regions. Accurate, precise and reproducible disease assessment is needed for monitoring epidemics and disease response in breeding...

108

A new Real-time PCR-method for the quantification of the Pine Pitch Canker fungus Fusarium circinatum.  

E-print Network

A new Real-time PCR-method for the quantification of the Pine Pitch Canker fungus Fusarium 3 4 5 spores (log 10) Thresholdcycle(Ct) Env. samples Calculate spores/m2 Real-time PCR with primer Method 3: Filter paper + Real-time PCR RESULTS We developed a specific primer pair (CIRC1A-CIRC4A

California at Berkeley, University of

109

112 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 THOUSAND CANKERS PATHWAY ASSESSMENT: MOVEMENT OF  

E-print Network

of walnut, identified by state cooperators, may threaten the native range of eastern black walnut, Juglans vector is the walnut twig beetle, Pityophthorus juglandis (WTB). The common name for the disease and thousand cankers disease (TCD) has caused walnut mortality in Washington, Oregon, California, Idaho, Utah

110

Transcriptional Profiling of Canker-Resistant Transgenic Sweet Orange (Citrus sinensis Osbeck) Constitutively Overexpressing a Spermidine Synthase Gene  

PubMed Central

Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating diseases affecting the citrus industry worldwide. In our previous study, the canker-resistant transgenic sweet orange (Citrus sinensis Osbeck) plants were produced via constitutively overexpressing a spermidine synthase. To unravel the molecular mechanisms underlying Xcc resistance of the transgenic plants, in the present study global transcriptional profiling was compared between untransformed line (WT) and the transgenic line (TG9) by hybridizing with Affymetrix Citrus GeneChip. In total, 666 differentially expressed genes (DEGs) were identified, 448 upregulated, and 218 downregulated. The DEGs were classified into 33 categories after Gene ontology (GO) annotation, in which 68 genes are in response to stimulus and involved in immune system process, 12 genes are related to cell wall, and 13 genes belong to transcription factors. These genes and those related to starch and sucrose metabolism, glutathione metabolism, biosynthesis of phenylpropanoids, and plant hormones were hypothesized to play major roles in the canker resistance of TG9. Semiquantitative RT-PCR analysis showed that the transcript levels of several candidate genes in TG9 were significantly higher than in WT both before and after Xcc inoculation, indicating their potential association with canker disease. PMID:23509803

Fu, Xing-Zheng; Liu, Ji-Hong

2013-01-01

111

Tall fescue is a potential spillover reservoir host for Alternaria species.  

PubMed

The spread of invasive species is complicated and multifaceted. Enemy spillover (i.e. the transfer of a natural enemy from a reservoir host to a novel host) is one mechanism that facilitates the spread of non-native species. The reservoir host is a species that harbors high abundance of the enemy with little cost to fitness. We asked whether Schedonorus arundinaceus (tall fescue), a highly invasive grass species in North America, is a potential reservoir host for the ubiquitous genus of fungi, Alternaria. We also asked whether spillover of Alternaria is possible among grasses that commonly occur with S. arundinaceus in grassland ecosystems. We performed a greenhouse cross inoculation of three isolates of Alternaria and six grass species (three native, three invasive, including S. arundinaceus). We determined that spillover is possible because the fungal isolates infected and caused disease symptoms on all six grasses and decreased biomass in two of the grass species. We also determined that the invasive grass species appear to be more competent hosts than the native species and that S. arundinaceus could be a likely reservoir host for Alternaria spp. because it can harbor the pathogen with no apparent fitness cost. PMID:24603832

Wilson, Hannah E; Carroll, George C; Roy, Bitty A; Blaisdell, G Kai

2014-01-01

112

Effect of Alternaria solani exudates on resistant and susceptible potato cultivars from two different pathogen isolates  

Technology Transfer Automated Retrieval System (TEKTRAN)

The resistance phenotypes of two potato cultivars to two isolates of Alternaria solani, causal agent of early blight, were studied under greenhouse conditions. The two isolates contain varying degrees of aggressiveness on both susceptible and resistant phenotypes of potatoes. A bioassay was used to ...

113

Fumonisins and Alternaria alternata lycopersici Toxins: Sphinganine Analog Mycotoxins Induce Apoptosis in Monkey Kidney Cells  

Microsoft Academic Search

Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell

Hong Wang; Clinton Jones; Janice Ciacci-Zanella; Todd Holt; David G. Gilchrist; Martin B. Dickman

1996-01-01

114

Release of alkenyl isothiocyanates and other volatiles from Brassica rapa seedlings during infection by Alternaria brassicae  

Microsoft Academic Search

When Brassica rapa seedlings were inoculated with the fungal pathogen Alternaria brassicae, 3-butenyl and 4-pentenyl isothiocyanates were released, together with dimethyl disulphide, dimethyl trisulphide, 4-oxoisophorone and a number of sesquiterpenes. Release of isothiocyanates is evidence for the catabolism of glucosinolates during infection, which is a prerequisite for their involvement in resistance.

Kevin J. Doughty; Margaret M. Blight; Clive H. Bock; Jane K. Fieldsend; John A. Pickett

1996-01-01

115

Biological standardization and maximum tolerated dose estimation of an Alternaria alternata allergenic extract  

Microsoft Academic Search

Background: The manufacture of allergenic extracts from the mold Alternaria alternata is influenced by factors such as strain variability, allergenic origin, culturing conditions and extraction process, which affect the reproducibility of the preparations intended for diagnostic and therapeutic use. Objectives: To select the most adequate antigenic source of A. alternata extracts and determine its maximum tolerated dose (MTD) to be

M. T. Lizaso; A. Martínez; J. A. Asturias; J. Algorta; B. Madariaga; N. Labarta; A. I. Tabar

116

Antifungal activity of several medicinal plants extracts against the early blight pathogen (Alternaria solani)  

Microsoft Academic Search

The antifungal activity for several medicinal plants against the early blight fungus (Alternaria solani) has been investigated. These plants were Syrian marjoram (Majorana syriaca), rosemary (Rosmarinus officinalis), Greek sage (Salvia fruticosa), roselle (Hibiscus sabdariffa) and cotton lavender (Santolina chamaecyparissus). The inhibitory effect of these extracts on the radial mycelial growth as well as on spore germination was measured in vitro

Saba J. Goussous; Firas M. Abu el-Samen; Ragheb A. Tahhan

2010-01-01

117

Antileukemic alpha-pyrone derivatives from the endophytic fungus Alternaria phragmospora  

Technology Transfer Automated Retrieval System (TEKTRAN)

Four new (1–4) and two known (5 and 6)a-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identi'ed to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (2) 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-py...

118

Analysis of genetic and pathogenic variation among Alternaria solani in a potato production region  

Technology Transfer Automated Retrieval System (TEKTRAN)

A two-year survey was conducted in a potato production region to investigate the genetic variability within naturally infecting populations of Alternaria solani, the cause of early blight in potato, and between species A. solani and A. dauci. Genetic diversity among 151 isolates was assessed using s...

119

Stem Cells  

MedlinePLUS

Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair ... body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

120

Artificial neural network models of relationships between Alternaria spores and meteorological factors in Szczecin (Poland)  

NASA Astrophysics Data System (ADS)

Alternaria is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we constructed predictive models for the fungal spore circulation in Szczecin, Poland. Monthly forecasting models were developed for the airborne spore concentrations of Alternaria, which is one of the most abundant fungal taxa in the area. Aerobiological sampling was conducted over 2004-2007, using a Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation; maximum and average wind speed; relative humidity; and maximum, minimum, average, and dew point temperature. The original factors as well as with lags (up to 3 days) were used as the explaining variables. Due to non-linearity and non-normality of the data set, the modelling technique applied was the artificial neural network (ANN) method. The final model was a split model with classification (spore presence or absence) followed by regression for spore seasons and log(x+1) transformed Alternaria spore concentration. All variables except maximum wind speed and precipitation were important factors in the overall classification model. In the regression model for spore seasons, close relationships were noted between Alternaria spore concentration and average and maximum temperature (on the same day and 3 days previously), humidity (with lag 1) and maximum wind speed 2 days previously. The most important variable was humidity recorded on the same day. Our study illustrates a novel approach to modelling of time series with short spore seasons, and indicates that the ANN method provides the possibility of forecasting Alternaria spore concentration with high accuracy.

Grinn-Gofro?, Agnieszka; Strzelczak, Agnieszka

2008-11-01

121

Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii  

PubMed Central

Background Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control. PMID:20388224

2010-01-01

122

Association of IL-4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma  

PubMed Central

Background Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked Alternaria sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying Alternaria sensitivity and asthma, in these studies we examined T cell responses to Alternaria antigens, HLA Class II restriction and HLA-DQ protection in children with severe asthma. Methods Sixty children with Alternaria-sensitive moderate-severe asthma were compared to 49 children with Alternaria-sensitive mild asthma. We examined HLA-DR and HLA-DQ frequencies in Alternaria-sensitive asthmatic by HLA typing. To determine ratios of Th1/Th2 Alternaria-specific T-cells, cultures were stimulated in media alone, Alternaria alternata extract and Alt a1. Sensitivity to IL-4 stimulation was measured by up-regulation of CD23 on B cells. Results Children with Alternaria-sensitive moderate-severe asthma trended to have increased sensitivities to Cladosporium (46% versus 35%), to Aspergillus (43% versus 28%), and significantly increased sensitivities to trees (78% versus 57%) and to weeds (68% versus 48%). The IL-4RA ile75val polymorphism was significantly increased in Alternaria-sensitive moderate-severe asthmatics, 83% (0.627 allele frequency) compared to Alternaria-sensitive mild asthmatics, 57% (0.388 allele frequency). This was associated with increased sensitivity to IL-4 stimulation measured by significantly increased IL-4 stimulated CD23 expression on CD19+ and CD86+CD19+ B cells of Alternaria-sensitive moderate-severe asthmatics. IL-5 and IL-13 synthesis was significantly increased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics to Alternaria extract and Alt a1 stimulation. The frequency of HLA-DQB1*03 allele was significantly decreased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics, 39% versus 63%, with significantly decreased allele frequency, 0.220 versus 0.398. Summary In children with Alternaria-sensitive moderate severe asthma, there was an increased Th2 response to Alternaria stimulation and increased sensitivity to IL-4 stimulation. This skewing towards a Th2 response was associated with an increased frequency of the IL-4RA ile75val polymorphism. In evaluating the HLA association, there was a decreased frequency of HLA-DQB1*03 in Alternaria-sensitive moderate severe asthmatic children consistent with previous studies suggest that HLA-DQB1*03 may be protective against the development of mold-sensitive severe asthma. PMID:20298583

2010-01-01

123

Effects of simulated rainfall on disease development and weed control efficacy of the bioherbicidal fungi alternaria cassiae and colletotrichum truncatum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria cassiae and Colletotrichum truncatum are virulent pathogens of sicklepod (Senna obtusifolia), and hemp sesbania (Sesbania exaltata), respectively, under favorable environmental conditions. In greenhouse experiments, the effects of simulated rainfall on pathogenesis and mortality of these ...

124

Adaptive Potential of Maritime Pine (Pinus pinaster) Populations to the Emerging Pitch Canker Pathogen, Fusarium circinatum  

PubMed Central

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

125

Adaptive potential of maritime pine (Pinus pinaster) populations to the emerging pitch canker pathogen, Fusarium circinatum.  

PubMed

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

126

Analysis of the isothiocyanates present in cabbage leaves extract and their potential application to control Alternaria rot in bell peppers  

Microsoft Academic Search

The potential use of cabbage isothiocyanates to control Alternaria rot in bell pepper was tested. Solid phase microextraction and gas chromatography–mass spectrometry found allyl, benzyl, 2-phenylethyl and phenyl isothiocyanates in a ratio of 1:3.5:5.3:9.6, respectively, in cabbage leaves. The same proportion was used to prepare an isothiocyanate mixture from reagent grade isothiocyanates (MCIT) to test the effect on Alternaria alternata

R. Troncoso; C. Espinoza; A. Sánchez-Estrada; M. E. Tiznado; Hugo S. García

2005-01-01

127

Canker Sores  

MedlinePLUS

... SLS is a foaming agent found in most toothpastes and mouthwashes. Finally, not getting the right nutrition, ... you brush your teeth . Brush and rinse with toothpastes and mouthwashes that don't contain sodium lauryl ...

128

Solubilization of Acid-Swollen Cellulose by an Enzyme System from a Species of Alternaria1  

PubMed Central

An unknown species of Alternaria, when grown on a medium containing carboxymethylcellulose as a carbon source produced a mixture of extracellular enzymes which solubilized acid-swollen cellulose. The product of the hydrolysis was a 1:2 molar mixture of cellobiose and glucose. The organism apparently produced no cellobiase. It is suggested that the mixture of cellulolytic enzymes contains at least two different enzymes which degrade cellulose in an endwise manner. PMID:16349671

Logan, Robert M.; Siehr, Donald J.

1966-01-01

129

Changes in the leaf proteome profile of Mentha arvensis in response to Alternaria alternata infection  

Microsoft Academic Search

Plant pathogenic fungi cause important yield losses in crops. A proteomic approach was used to study the changes in the leaf proteome profile of the plant Mentha arvensis infected with a necrotrophic fungus, Alternaria alternata. High-resolution two-dimensional gel electrophoresis (2-DE) followed by colloidal Coomassie staining and mass spectrometric analysis was used to identify highly abundant proteins differentially expressed in response

Ragini Sinha; Sharmila Chattopadhyay

2011-01-01

130

Maculosin, a Host-Specific Phytotoxin for Spotted Knapweed from Alternaria alternata  

Microsoft Academic Search

Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo-(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the

Andrea C. Stierle; John H. Cardellina; Gary A. Strobel

1988-01-01

131

TPCP: Pitch canker PITCH CANKER  

E-print Network

to commercial forestry in South Africa today. In the past seven years, Fusarium subglutinans f.sp. pini or FSP successful control. Insects such as Ips spp., Pityophthorus spp., Pissodes sp. and Conophthorus spp. have

132

The complete genome sequence of a novel mycovirus from Alternaria longipes strain HN28.  

PubMed

The complete nucleotide sequence of Alternaria longipes dsRNA virus 1 (AlRV1), a novel double-stranded RNA (dsRNA) mycovirus, was determined and analyzed. AlRV1-HN28 contains a single dsRNA genome segment 3415 base pairs in length (excluding the 3' poly(A) tail) and was predicted to contain two discontiguous open reading frames (ORFs, ORF A and ORF B). The 5'-proximal ORF A (1182 nt) potentially encodes a protein of 394 amino acids (aa) with a predicted molecular mass of 43 kDa; this protein showed no significant similarities to any other sequences in any of the NCBI protein databases. The 3'-proximal ORF B (1737 nt) encodes a protein of 579 aa with a predicted molecular mass of 65 kDa; this protein sequence shares similarities with the conserved domains of RNA-dependent RNA polymerases of other mycoviruses. Phylogenetic analysis indicated that AlRV1-HN28 was closely related to four other unclassified viruses, which suggests that the AlRV1-HN28 isolated from Alternaria longipes may belong to a new family of dsRNA mycoviruses. This is the first report of the full-length nucleotide sequence of a mycovirus that infects Alternaria longipes. PMID:25248625

Lin, Yanhong; Zhang, Hailong; Zhao, Chengjin; Liu, Shengxue; Guo, Lihua

2015-02-01

133

Alternaria and Cladosporium Fungal Allergen Epitopes are Denatured by Sodium Hypochlorite  

PubMed Central

Background Fungal allergens are ubiquitous; however, little progress has been made understanding fungal allergenic material removal from indoor environments. Purpose We investigated removal of environmental allergenic material derived from Alternaria and Cladosporium using sodium hypochlorite in vivo and in vitro. Methods Freeze dried allergen extract from Alternaria alternata and Cladosporium herbarum was treated with hypochlorite concentrations of 322, 88, 38, 16, 3, 0.3, and 0 mM, respectively. Remaining native allergenic material was quantified using enzyme immunoassay and remaining viable fungal material was evaluated. Results The results of treating Alternaria or Cladosporium extract with sodium hypochlorite are immediate and obvious. Concentrations greater than 100 mM remove color and concentrations between 100 and 38 mM partially uncolored the extract. Immunoassay for total antigenic and allergenic material remaining after treatment with sodium hypochlorite including 2 concentrations recommended for killing fungus confirmed a general destruction of antigenic and allergenic material at concentrations of 38 mM or greater. Conclusions This work confirms the ability of solutions of sodium hypochlorite to denature fungal allergenic material from common outdoor and indoor fungi A. alternata and C. herbarum. Destruction of recognized antigenic and allergenic epitopes occurs at hypochlorite concentrations commonly used for household cleaning. PMID:23282316

2009-01-01

134

Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma.  

PubMed

A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA when grown at 25 degrees C with an alternating light/dark cycle consisting of 8 h of cool-white daylight followed by 16 h darkness. Addition of 1.5% MnCl(2) 4 H(2)O (w/v) inhibited most other fungi than Alternaria, Epicoccum and Phoma species when tested on pure cultures. The mycobiota of two soil samples and eight grain samples were examined using PCA-Mn and three commonly used isolation media, DRYES, DG18 and V8. On the three conventional media growth of several genera was observed with the predominant being Aspergillus, Eurotium, Fusarium, Mucor, Penicillium and Rhizopus. Of these only F. oxysporum and F. verticillioides were able to grow on PCA-Mn. Alternaria infectoria and Epicoccum nigrum were present in three cereal grain samples, but emerged to a far lower degree on the three conventional media compared to PCA-Mn. Three black spored fungi, identified as Phoma eupyrena, Paraconiothyrium minitan and one unknown species, were isolated from the two soil samples when incubated on PCA-Mn but were absent on the three conventional media. PMID:19185378

Sørensen, Jens Laurids; Mogensen, Jesper Mølgaard; Thrane, Ulf; Andersen, Birgitte

2009-03-15

135

Effects of meteorological factors on the levels of Alternaria spores on a potato crop  

NASA Astrophysics Data System (ADS)

Alternaria solani Soraeur produces early blight in Solanum tuberosum L., leading to significant agricultural losses. The current study was carried out on the extensive potato crop situated in north-western of Spain during 2007, 2008 and 2009. In this area potato crops are the most important source of income. In this work we used a Hirst-type volumetric spore-trap for the aerobiological monitoring of Alternaria spores. The highest spore concentrations were recorded during the 2009 cycle (10,555 spores), and the lowest concentrations were recorded during the 2008 cycle (5,471 spores). Over the 3 years of study, the highest concentrations were registered during the last stage of the crop. The aim of the study was to observe the influence of meteorological factors on the concentration of Alternaria spores, which can lead to serious infection and early blight. Prediction of the stages during which a crop is particularly vulnerable to infection allows for adjustment of the application of fungicide and is of environmental and agricultural importance. For this reason, we tested three models (P-Days, DD and IWP) to predict the first treatment and decrease the negative effect that these spores have on potato crops. The parameter that showed the most significant correlation with spore concentrations was minimum temperature. We used ARIMA (autoregressive integrated model of running mean) time-series models to determine the forecast. We considered weather data as predictor variables and the concentration of spores on the previous day as the fixed variable.

Escuredo, Olga; Seijo, Maria Carmen; Fernández-González, Maria; Iglesias, Isabel

2011-03-01

136

Genetic variation and host specificity of Phytophthora citrophthora isolates causing branch cankers in Clementine trees in Spain  

Microsoft Academic Search

Considerable tree losses have been observed during the past few years in Spain due to Phytophthora branch canker of clementines\\u000a caused by Phytophthora citrophthora. The emergence of this disease led to the speculation that either the pathogen has evolved increasing its aggressiveness\\u000a or specificity to clementines. A total of 134 isolates of P. citrophthora collected from 2003 to 2005 in

Luis Armando Alvarez; Maela León; Paloma Abad-Campos; José García-Jiménez; Antonio Vicent

2011-01-01

137

The role of meteorological factors in determining the annual variation of Alternaria and Cladosporium spores in the atmosphere of Palencia, 1990 1992  

NASA Astrophysics Data System (ADS)

A study was made of the daily content of Alternaria and Cladosporium spores in the atmosphere in Palencia city (Spain) for three consecutive years 1990 1992. Alternaria and Cladosporium represented 55% of the total identified spores, presenting an annual distributional pattern of which the maximum values were reached in summer. Multiple regression analyses showed a positive correlation between minimum temperature and Cladosporium spore concentrations, while for Alternaria there was a positive correlation with maximum temperature and a negative correlation with precipitation. Duncan's multiple range test among means of Alternaria data indicated that winds coming from a northeasterly direction were associated with significantly higher concentrations the spores.

Herrero, B.; Fombella-Blanco, M. A.; Fernández-González, D.; Valencia-Barrera, R. M.

1996-09-01

138

Brenneria populi sp. nov., isolated from symptomatic bark of Populus×euramericana canker.  

PubMed

Five Gran-stain-negative, facultatively anaerobic, motile, bacterial strains were isolated from symptomatic bark tissue of Populus×euramericana canker. Strains grew at 4-41 °C, pH 4-10 and 0-6?% (w/v) salinity. They were positive with respect to catalase activity and negative for oxidase activity, nitrate reduction and the Voges-Proskauer reaction. Analysis of 16S rRNA gene sequences indicated that these five poplar isolates belong to the genus Brenneria, having highest sequence similarity of 95.98?% with Brenneria goodwinii LMG 26270(T). These five isolates formed a single cluster based on multilocus sequence analysis, indicating that they all belong to a single taxon within the genus Brenneria, which was confirmed by DNA-DNA hybridization. The DNA G+C content was 54.9-55.7 mol%, and the main fatty acids were C16?:?0, C18?:?1?7c, C17?:?0 cyclo and C16?:?1?7c/iso-C15?:?0 2-OH. Based on these results, we describe a novel species of the genus Brenneria with the proposed name Brenneria populi sp. nov. The type strain is D9-5(T) (?=?CFCC 11963(T)?=?KCTC 42088(T)). PMID:25385993

Li, Yong; Fang, Wei; Xue, Han; Liang, Wen-Xing; Wang, Lai-Fa; Tian, Guo-Zhong; Wang, Xi-Zhuo; Lin, Cai-Li; Li, Xia; Piao, Chun-Gen

2015-02-01

139

Novel hosts of the Eucalyptus canker pathogen Chrysoporthe cubensis and a new Chrysoporthe species from Colombia.  

PubMed

The pathogen Chrysoporthe cubensis (formerly Cryphonectria cubensis) is best known for the important canker disease that it causes on Eucalyptus species. This fungus is also a pathogen of Syzygium aromaticum (clove), which is native to Indonesia, and like Eucalyptus, is a member of Myrtaceae. Furthermore, C. cubensis has been found on Miconia spp. native to South America and residing in Melastomataceae. Recent surveys have yielded C. cubensis isolates from new hosts, characterized in this study based on DNA sequences for the ITS and beta-tubulin gene regions. These hosts include native Clidemia sericea and Rhynchanthera mexicana (Melastomataceae) in Mexico, and non-native Lagerstroemia indica (Pride of India, Lythraceae) in Cuba. Isolates from these hosts and areas group in the sub-clade of C. cubensis accommodating the South American collections of the fungus. This sub-clade also includes isolates recently collected from Eucalyptus in Cuba, which are used to epitypify C. cubensis. New host records from Southeast Asia include exotic Tibouchina urvilleana from Singapore and Thailand and native Melastoma malabathricum (Melastomataceae) in Sumatra, Indonesia. Consistent with their areas of occurrence isolates from the latter collections group in the Asian sub-clade of C. cubensis. DNA sequence comparisons of isolates from Tibouchina lepidota in Colombia revealed that they represent a new sub-clade within the greater Chrysoporthe clade. Isolates in this clade are described as Chrysoporthe inopina sp. nov., based on distinctive morphological differences. PMID:16876702

Gryzenhout, Marieka; Rodas, Carlos A; Portales, Julio Mena; Clegg, Paul; Wingfield, Brenda D; Wingfield, Michael J

2006-07-01

140

Summer heat and low soil organic matter influence severity of hazelnut Cytospora canker.  

PubMed

Cytospora canker, caused by the fungus Cytospora corylicola, is present in hazelnut production areas worldwide. The disease is widespread throughout the main production areas of Italy. The causal agent is considered to be a secondary invader of damaged tissue that attacks mainly stressed plants. However, little is known of disease severity and stress factors that predispose plants to infection. In particular, the role of pedoclimatic factors was investigated. Direct survey indicated that disease severity varied across several study sites. Geostatistics showed a strong positive correlation between disease severity index and summer heat (r = 0.80 and 0.91 for July and August, respectively) and strong negative correlation between disease severity index and soil organic matter (r = -0.78). A moderate positive correlation between disease severity index and magnesium/potassium ratio (r = 0.58) and moderate negative correlations between disease severity index and total soil nitrogen (r = -0.53), thermal shock (r = -0.46), and rainfall (r = -0.53) were determined. No significant correlation between disease severity index and soil aluminum (r = -0.35), soil pH (r = -0.01), and plant age (r = -0.38) was found. PMID:24168042

Lamichhane, Jay Ram; Fabi, Alfredo; Varvaro, Leonardo

2014-04-01

141

Alternaria alternata allergen, Alt a 1 - a unique, ?-barrel protein dimer exclusively found in fungi  

PubMed Central

Background Alternaria is one of the most common molds associated with allergic diseases and 80% of Alternaria-sensitive patients produce IgE antibodies to a major protein allergen, Alt a 1. The structure and function of Alt a 1 is unknown. Objective To obtain a high resolution structure of Alt a 1 by X-ray crystallography and to investigate structural relationships between Alt a 1 and other allergens and proteins reported in the Protein Data Bank. Methods X-ray crystallography was used to determine the structure of Alt a 1 using a custom-designed set of crystallization conditions. An initial Alt a 1 model was determined by the application of a Ta6Br122+ cluster and Single-wavelength Anomalous Diffraction. Bioinformatic analyses were used to compare the Alt a 1 sequence and structure with other proteins. Results Alt a 1 is a unique ?-barrel comprising 11 ?-strands and forms a ‘butterfly-like’ dimer linked by a single disulfide bond, with a large (1345Å2) dimer interface. Intramolecular disulfide bonds are conserved among Alt a 1 homologs. Currently, the Alt a 1 structure has no equivalent in the Protein Data Bank. Bioinformatics analyses suggest that the structure is found exclusively in fungi. Four previously reported putative IgE binding peptides have been located on the Alt a 1 structure. Conclusions Alt a 1 has a unique, dimeric ?-barrel structure that appears to define a new protein family with unknown function found exclusively in fungi. The location of IgE antibody binding epitopes is in agreement with the structural analysis of Alt a 1.The Alt a 1 structure will allow mechanistic structure/function studies and immunologic studies directed towards new forms of immunotherapy for Alternaria-sensitive allergic patients. PMID:22664167

Chruszcz, Maksymilian; Chapman, Martin D.; Osinski, Tomasz; Solberg, Robert; Demas, Matthew; Porebski, Przemyslaw J.; Majorek, Karolina A.; Pomés, Anna; Minor, Wladek

2012-01-01

142

Exposure to Alternaria alternata in US homes is associated with asthma symptoms  

PubMed Central

Background Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments. Objective We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes. Methods The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti–A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors. Results Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90?2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18?2.85 for the 3rd tertile). Conclusion Exposure to A alternata in US homes is associated with active asthma symptoms. Clinical implications Measures that reduce indoor exposure to A alternata may help control asthma exacerbations. PMID:17030243

Salo, Päivi M.; Arbes, Samuel J.; Sever, Michelle; Jaramillo, Renee; Cohn, Richard D.; London, Stephanie J.; Zeldin, Darryl C.

2007-01-01

143

Association of IL4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma  

Microsoft Academic Search

BACKGROUND: Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked Alternaria sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying Alternaria sensitivity and asthma, in these studies we examined T

Alan P Knutsen; Hari M Vijay; Barbara Kariuki; Luis A Santiago; Ralph Graff; Jonathan D Wofford; Maulik R Shah

2010-01-01

144

Frequency distribution and assessment of genetic diversity of novel endophyte Alternaria alternata accessions isolated from Pongamia pinnata L.  

PubMed

Thepresent study discusses the frequency distribution and genetic diversity of novel fungal endopyte Alternaria alternata within the Pongammia pinnata plant samples. A total of ten plant samples of Pongammia pinnata, Pierre. (Karanja) were collected from specific locations of Sanganer region of Rajasthan for the isolation of fungal endophytes. Of these, maximum frequency of Alternaria alternata (22.29%) were recorded which are morphologically similar but ecologically variant. Efficacy of randomly amplified polymorphic DNA (RAPD), were assessed in seventeen individuals of the primers was GCC 180 where as 10 bands were generated by GCC 181. The similarity coefficient matrix generated for the primers was subjected to algorithm UPGMA (Unweighted Pair Group Method Analysis) and clusters were generated using NTSYS 2.02 pc program. To stabilize the level of relatedness among the seventeen ecologically variant Alternaria alternata accessions, the dendrogram was constructed, which showed that all the isolates were diversified endophytically with in the plant Pongamia pinnata. PMID:24502162

Tiwari, Kartikeya

2013-10-01

145

Inheritance of resistance to southern stem canker (Diaporthe phaseolorum f.s. meridionalis) in soybean [Glycine max (L.) Merr.  

E-print Network

Number of Plants. Expected Value Res. Sus. Res. Sus. 340-1 340-2 340-3 340-4 67 31 28 50 24 5 7 27 68. 25 27. 00 26. 25 57. 75 22. 75 0. 09 9. 00 2. 37 8. 75 0. 47 19. 25 4. 16 Sums Pooled 176 63 179. 25 59. 75 7. 09 0, 24... 338. Table 9. Chi-square test for homogeneity of F, population of the cross Dowling x Coker 338 to 3:1 ratio. F, sub-populations Observed Number of Plants. Expected X' Value Res. Sus. Res. Sus. 320-1 320-2 320-3 320-4 320-5 320-6 320-7...

Ngeleka, Kadima

2012-06-07

146

Effects of the nematicide 1,3-dichloropropene on weed populations and stem canker disease severity in potatoes  

Microsoft Academic Search

The soil fumigant 1,3-dichloropropene (1,3-D) has been used in the UK for the control of potato cyst nematodes (PCN), Globodera pallida (Stone) and Globodera rostochiensis (Wollenweber), but its potential herbicidal activity has not been extensively investigated in this country. Field and glasshouse studies were therefore conducted to evaluate the potential of 1,3-D for the control of weeds in potatoes, and

Patrick P. J. Haydock; Thomas Deliopoulos; Ken Evans; Stephen T. Minnis

2010-01-01

147

Recovery Plan for Phytophthora kernoviae Causing Bleeding Trunk Cankers, Leaf Blight and Stem Dieback in Trees and Shrubs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phytophthora kernoviae, a recently described species of Phytophthora, is an invasive pathogen of forest trees and shrubs such as beech (Fagus sylvatica) and rhododendron (Rhododendron ponticum) that has become established in woodlands and public gardens in Cornwall, United Kingdom. Although the ori...

148

Two new triterpenoid saponins obtained by microbial hydrolysis with Alternaria alternata AS 3.6872.  

PubMed

Compound 1, a triterpenoid saponin from Ardisia gigantifolia Stapf showing potential anti-tumour activity, was hydrolysed into two deglycosyl derivatives (2 and 3) by Alternaria alternata AS 3.6872. Both these derivatives are new compounds. Their structures were elucidated on the basis of 1D, 2D NMR, HR-ESI-MS and optical rotation spectral data. Compounds 1-3 were evaluated for their cytotoxicity against human hepatocellular carcinoma and normal liver cells by Cell Counting Kit 8 colorimetric assay. PMID:25421632

Mu, Li-Hua; Gu, Yong-Jie; Ma, Bai-Ping; Lu, Li; Liu, Ping

2014-11-25

149

Alternaria arborescens Infection in a Healthy Individual and Literature Review of Cutaneous Alternariosis.  

PubMed

A 28-year-old man presented at our clinic with 1-month history of an ulcer covered with crust on his left anterior tibia. Based on the morphological features and molecular identification, the patient was diagnosed as cutaneous alternariosis caused by Alternaria arborescens. He was successfully cured by oral itraconazole and topical use of 0.25 % liposomal amphotericin B. A review of published studies revealed 29 cases of cutaneous alternariosis. Most cases (90 %) occurred in immunosuppressed patients; itraconazole (59 %) and voriconazole (24 %) are the most effective treatments of choices. PMID:25370461

Hu, Wenying; Ran, Yuping; Zhuang, Kaiwen; Lama, Jebina; Zhang, Chaoliang

2015-02-01

150

Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata.  

PubMed

Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10(-5) M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the fungus possessed either less activity or none at all. In tests against 19 plant species, maculosin was phytotoxic only to spotted knapweed. Thus maculosin is a host-specific phytotoxin from a weed pathogen. PMID:16593989

Stierle, A C; Cardellina, J H; Strobel, G A

1988-11-01

151

DNA Polymorphisms and Biocontrol of Bacillus Antagonistic to Citrus Bacterial Canker with Indication of the Interference of Phyllosphere Biofilms  

PubMed Central

Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S–23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease. PMID:22848728

Huang, Tzu-Pi; Tzeng, Dean Der-Syh; Wong, Amy C. L.; Chen, Chun-Han; Lu, Kuan-Min; Lee, Ya-Huei; Huang, Wen-Di; Hwang, Bing-Fang; Tzeng, Kuo-Ching

2012-01-01

152

Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri.  

PubMed

The genome of Xanthomonas citri subsp. Citri strain 306 pathotype A (Xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics Xac and its host compatible have been developed, specially related to adaptive events that allow the survival of Xac within the plant. Proteomic analysis of Xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with its plant host. The results also indicate the importance of a group of proteins that may not be directly related to the classical virulence factors, but that are likely fundamental to the success of the initial stages of the infection, such as methyl-accepting chemotaxis protein (Mcp) and phosphate specific transport (Pst). Furthermore, the analysis of the mutant of the gene pstB which codifies to an ABC phosphate transporter subunit revealed a complete absence of citrus canker symptoms when inoculated in compatible hosts. We also conducted an in silico analysis which established the possible network of genes regulated by two-component systems PhoPQ and PhoBR (related to phosphate metabolism), and possible transcriptional factor binding site (TFBS) motifs of regulatory proteins PhoB and PhoP, detaching high degree of conservation of PhoB TFBS in 84 genes of Xac genome. This is the first time that chemotaxis signal transduction and phosphate metabolism were therefore indicated to be fundamental to the process of colonization of plant tissue during the induction of disease associated with Xanthomonas genus bacteria. PMID:25403594

Moreira, Leandro Marcio; Facincani, Agda Paula; Ferreira, Cristiano Barbalho; Ferreira, Rafael Marine; Ferro, Maria Inês Tiraboshi; Gozzo, Fabio Cesar; de Oliveira, Julio Cezar Franco; Ferro, Jesus Aparecido; Soares, Márcia Regina

2014-11-18

153

Bayesian Analysis for Inference of an Emerging Epidemic: Citrus Canker in Urban Landscapes  

PubMed Central

Outbreaks of infectious diseases require a rapid response from policy makers. The choice of an adequate level of response relies upon available knowledge of the spatial and temporal parameters governing pathogen spread, affecting, amongst others, the predicted severity of the epidemic. Yet, when a new pathogen is introduced into an alien environment, such information is often lacking or of no use, and epidemiological parameters must be estimated from the first observations of the epidemic. This poses a challenge to epidemiologists: how quickly can the parameters of an emerging disease be estimated? How soon can the future progress of the epidemic be reliably predicted? We investigate these issues using a unique, spatially and temporally resolved dataset for the invasion of a plant disease, Asiatic citrus canker in urban Miami. We use epidemiological models, Bayesian Markov-chain Monte Carlo, and advanced spatial statistical methods to analyse rates and extent of spread of the disease. A rich and complex epidemic behaviour is revealed. The spatial scale of spread is approximately constant over time and can be estimated rapidly with great precision (although the evidence for long-range transmission is inconclusive). In contrast, the rate of infection is characterised by strong monthly fluctuations that we associate with extreme weather events. Uninformed predictions from the early stages of the epidemic, assuming complete ignorance of the future environmental drivers, fail because of the unpredictable variability of the infection rate. Conversely, predictions improve dramatically if we assume prior knowledge of either the main environmental trend, or the main environmental events. A contrast emerges between the high detail attained by modelling in the spatiotemporal description of the epidemic and the bottleneck imposed on epidemic prediction by the limits of meteorological predictability. We argue that identifying such bottlenecks will be a fundamental step in future modelling of weather-driven epidemics. PMID:24762851

Neri, Franco M.; Cook, Alex R.; Gibson, Gavin J.; Gottwald, Tim R.; Gilligan, Christopher A.

2014-01-01

154

Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease.  

PubMed

Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccA(w), induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B; Yang, Bing; White, Frank F; Wang, Nian; Jones, Jeffrey B

2014-01-28

155

Bayesian analysis for inference of an emerging epidemic: citrus canker in urban landscapes.  

PubMed

Outbreaks of infectious diseases require a rapid response from policy makers. The choice of an adequate level of response relies upon available knowledge of the spatial and temporal parameters governing pathogen spread, affecting, amongst others, the predicted severity of the epidemic. Yet, when a new pathogen is introduced into an alien environment, such information is often lacking or of no use, and epidemiological parameters must be estimated from the first observations of the epidemic. This poses a challenge to epidemiologists: how quickly can the parameters of an emerging disease be estimated? How soon can the future progress of the epidemic be reliably predicted? We investigate these issues using a unique, spatially and temporally resolved dataset for the invasion of a plant disease, Asiatic citrus canker in urban Miami. We use epidemiological models, Bayesian Markov-chain Monte Carlo, and advanced spatial statistical methods to analyse rates and extent of spread of the disease. A rich and complex epidemic behaviour is revealed. The spatial scale of spread is approximately constant over time and can be estimated rapidly with great precision (although the evidence for long-range transmission is inconclusive). In contrast, the rate of infection is characterised by strong monthly fluctuations that we associate with extreme weather events. Uninformed predictions from the early stages of the epidemic, assuming complete ignorance of the future environmental drivers, fail because of the unpredictable variability of the infection rate. Conversely, predictions improve dramatically if we assume prior knowledge of either the main environmental trend, or the main environmental events. A contrast emerges between the high detail attained by modelling in the spatiotemporal description of the epidemic and the bottleneck imposed on epidemic prediction by the limits of meteorological predictability. We argue that identifying such bottlenecks will be a fundamental step in future modelling of weather-driven epidemics. PMID:24762851

Neri, Franco M; Cook, Alex R; Gibson, Gavin J; Gottwald, Tim R; Gilligan, Christopher A

2014-04-01

156

A rare case of allergic bronchopulmonary mycosis caused by Alternaria alternata.  

PubMed

A rare case of allergic bronchopulmonary mycosis (ABPM), caused by Alternaria alternata, is reported in an immunocompetent resident of Delhi. Her complaints included a generalized, urticarial skin rash and occasional pain in the right lower chest. Her differential count showed eosinophils, 22%; absolute eosinophil count (AEC), 2400 cells/?l; and total IgE, 4007 IU/ml. The computerised tomogram (CT) scan of her thorax showed an enhancing lesion with surrounding ground glass haziness in the right lower lobe. Histopathologic examination of the resected lung revealed a necrotizing granulomatous inflammation, parenchymal infiltration by eosinophils, lymphocytes, neutrophils, plasma cells and some exudative bronchiolitis suggestive of ABPM. Observation of KOH wet mounts of repeat sputum and BAL samples demonstrated the presence of septate, brownish hyphae and cultures of these specimens yielded A. alternata (identified by sequencing of the ITS region). Her serum showed a three-fold higher specific IgE to A. alternata antigens than control levels, and the type I cutaneous hypersensitivity response to antigens of A. alternata was strongly positive. She was treated successfully with oral glucocorticoids and itraconazole. To our knowledge, ABPM due to Alternaria alternata has not been reported previously. PMID:22563857

Chowdhary, Anuradha; Agarwal, Kshitij; Randhawa, H S; Kathuria, Shallu; Gaur, S N; Najafzadeh, Mohammad J; Roy, P; Arora, Naveen; Khanna, Geetika; Meis, Jacques F

2012-11-01

157

Conservation of the genes for HC-toxin biosynthesis in Alternaria jesenskae  

PubMed Central

Background HC-toxin, a cyclic tetrapeptide, is a virulence determinant for the plant pathogenic fungus Cochliobolus carbonum. It was recently discovered that another fungus, Alternaria jesenskae, also produces HC-toxin. Results The major genes (collectively known as AjTOX2) involved in the biosynthesis of HC-toxin were identified from A. jesenskae by genomic sequencing. The encoded orthologous proteins share 75-85% amino acid identity, and the genes for HC-toxin biosynthesis are duplicated in both fungi. The genomic organization of the genes in the two fungi show a similar but not identical partial clustering arrangement. A set of representative housekeeping proteins show a similar high level of amino acid identity between C. carbonum and A. jesenskae, which is consistent with the close relatedness of these two genera within the family Pleosporaceae (Dothideomycetes). Conclusions This is the first report that the plant virulence factor HC-toxin is made by an organism other than C. carbonum. The genes may have moved by horizontal transfer between the two species, but it cannot be excluded that they were present in a common ancestor and lost from other species of Alternaria and Cochliobolus. PMID:23865912

2013-01-01

158

Participation of the phosphoinositide metabolism in the hypersensitive response of Citrus limon against Alternaria alternata.  

PubMed

Lemon seedlings inoculated with Alternaria alternata develop a hypersensitive response (HR) that includes the induction of Phenylalanine ammonia-lyase (PAL, E. C. 4.3.1.5) and the synthesis of scoparone. The signal transduction pathway involved in the development of this response is unknown. We used several inhibitors of the Phosphoinositide (PI) animal system to study a possible role of Inositol-1,4,5-triphosphate (IP3) in the transduction of the fungal conidia signal in Citrus limon. The HR was only partially inhibited by EGTA, suggesting that not only external but internal calcium as well are necessary for a complete development of the HR. In this plant system, Alternaria alternata induced an early accumulation of the second messenger IP3. When lemon seedlings were watered long term with LiCl, an inhibitor of the phosphoinositide cycle, the IP3 production was reduced, and the LiCl-watered plants could neither induce PAL nor synthesize scoparone in response to fungal conidia. Furthermore, neomycin, a Phospholipase C (PLC, E. C. 3.1.4.3) inhibitor, also inhibited PAL induction and scoparone synthesis in response to A. alternata. These results suggest that IP3 could be involved in the signal transduction pathway for the development of the HR of Citrus limon against A. alternata. PMID:11471522

Ortega, X; Pérez, L M

2001-01-01

159

Molecular cloning and heterologous expression of an acid stable xylanase gene from Alternaria sp. HB186.  

PubMed

A new xylanase gene, named xyn186, was cloned by the genome-walking PCR method from the Alternaria sp. HB186. The sequence of xyn186 contains a 748 bp open reading frame separated by one intron with the size of 52 bp. The cDNA was obtained by DpnI-mediated intron deletion. The cDNA was cloned into pHBM905A and transformed into Pichia pastoris GS115 to screen xylanase-secreting transformants on RBB-xylan plates. The molecular mass of the enzyme was estimated to be 23 kDa on SDS-PAGE. The optimal pH and temperature of the purified enzyme is 6 and 50°C, respectively. The K (m) and V (max) valued for birchwood xylan are 1.404 mg ml(-1) and 0.2748 mmol min(-1) mg(-1), respectively. The inhibitory effects of various metal ions were investigated, Cu(2+) and Hg(2+) ions inhibited most of the enzyme activity. The gene copy number of xyn186 in the genome of P. pastoris was estimated as two by the Real-time PCR. To date, xyn186 gene is the first xylanase gene cloned from the genus Alternaria. PMID:22805796

Mao, Liangwei; Meng, Po; Zhou, Cheng; Ma, Lixin; Zhang, Guimin; Ma, Yanhe

2012-03-01

160

Effects of Alternaria destruens, Glyphosate, and Ammonium Sulfate Individually and Integrated for Control of Dodder (Cuscuta pentagona)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dodder is a serious weed problem in several crops. Its minutely sized, easily dispersed, and highly viable seed makes it difficult to control. Alternaria destruens is the active ingredient in a registered bioherbicide for control of dodder species. In greenhouse studies, the following treatments ...

161

First Report of a Leaf Spot Caused by Alternaria brassicae on the Invasive Weed Lepidium draba in North America  

Technology Transfer Automated Retrieval System (TEKTRAN)

A second leaf spot disease on the perennial invasive weed white top, aka hoary cress, was found in a stand of white top in south central Montana. The plant pathogen causing the lesions was identified as the fungus Alternaria brassicae. It was isolated, purified grown on a V-8 agar growth medium and ...

162

The epidemiological significance of post-packinghouse survival of Xanthomonas citri ssp. citri for dissemination of Asiatic citrus canker via infected fruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

The risk of introduction of Xanthomonas citri spp. citri (Xcc) to new, unaffected citrus producing areas is a major concern for those citrus industries attempting to remain free of citrus canker. Citrus fruit, as a potential pathway for Xcc to enter and become established in these areas, is assumed...

163

SPATIAL PATTERN ANALYSIS OF CITRUS CANKER INFECTED PLANTINGS IN SÃO PAULO BRAZIL AND IMPLICATION OF THE ASIAN LEAFMINER ON THE POTENTIAL DISPERSAL PROCESSES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Eradication of Asiatic Citrus Canker (ACC) has become increasingly difficult over the last decade following the introduction of the Asian leafminer into Brazil and Florida, which lead to changes in the eradication protocols. The present study, undertaken in Brazil, was aimed at characterizing the s...

164

POST-HURRICANE ANALYSIS OF CITRUS CANKER II: PREDICTIVE MODEL ESTIMATION OF DISEASE SPREAD AND AREA POTENTIALLY IMPACTED BY VARIOUS ERADICATION PROTOCOLS FOLLOWING CATASTROPHIC WEATHER EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The affect of 2005 Hurricane Wilma on the dissemination of Xanthomonas axonopodis pv. citri (Xac), the cause of Asiatic citrus canker (ACC), and subsequent disease development was examined and predictions for the areas into which Xac was likely to have spread from known sources of infection was deve...

165

POST-HURRICANE ANALYSIS OF CITRUS CANKER SPREAD AND PROGRESS TOWARDS THE DEVELOPMENT OF A PREDICTIVE MODEL FOR FUTURE WEATHER RELATED SPREAD  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (Xanthonomas axonopodis pv. citri) has had a long history in Florida and has been introduced multiple times since the early 1900’s. With each introduction or discovery, eradication programs have been implemented to attempt to eliminate the disease. The most recent eradication...

166

THE CHANGE IN QUANTITY OF BACTERIA OF XANTHOMONAS AXONOPODIS PV CITRI DISPERSED DOWN WIND FROM CANKER-INFECTED GRAPEFRUIT TREES DURING A WIND/RAIN EVENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The yield and marketability of citrus is limited in several tropical wet parts of the world by citrus canker (caused by Xanthomonas axonopodis pv. citri, Xac). The disease can cause severe epidemics and there are few options for control, although eradication has been favored (1). A thorough knowledg...

167

Effects of Mefenoxam, Phosphonate, and Paclobutrazol on In Vitro Characteristics of Phytophthora cactorum and P. citricola and on Canker Size of European Beech  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phytophthora citricola and P. cactorum cause bleeding cankers that lead to the death of mature European beech in the northeastern United States. Because of the economic value placed on these trees, experiments were conducted to investigate the effects of two fungicides and a plant growth regulator ...

168

ESTIMATING THE INCREASE AND SPREAD OF CITRUS CANKER CAUSED BY THE INTERACTION OF PEDESTRIAN VERSUS CATASTROPHIC WEATHER EVENTS, HUMANS, AND BAD LUCK  

Technology Transfer Automated Retrieval System (TEKTRAN)

The bacteria, Xanthomonas axonopodis pv. citri (Xac), that causes Asiatic Citrus Canker (ACC) can move in any of a variety of modes in the presence of free moisture. From a meteorological point of view, gentle rain, rain with wind, rain storms, tropical storms, and hurricanes can all disperse Xac i...

169

STEM Career  

NSDL National Science Digital Library

There are many groups and organizations in the United States working to encourage young people to enter STEM-related careers, and this website represents one of those endeavors. The STEM Career website was created by Professor Rich Feller of Colorado State University to help encourage young people to select just such a career path. The website contains updates on STEM career possibilities, and basic answers to questions like "Why STEM?" and "Why STEM Centric Career Development?" Visitors should also scan through the "STEM Disciplines" area on the homepage, as it contains resources about the job outlook for related STEM disciplines, such as biochemical engineering and engineering managers. Moving on, the site also features news updates from Professor Feller and his colleagues on subjects that include the ways in which corporations are promoting STEM education and women in STEM.

170

Use of a climatic rule and fuzzy sets to model geographic distribution of climatic risk for European canker (Neonectria galligena) of apple.  

PubMed

A rule-based model was developed to assess climatic risk of European canker (Neonectria galligena), which is a major disease of apple in some temperate zones. A descriptive rule was derived from published observations on climatic conditions favorable for European canker development. Fuzzy set theory was used to evaluate the descriptive rule quantitatively. The amount and frequency of rainfall and the average number of hours between 11 and 16°C/day were used as input variables whose values were matched with terms in the rule, e.g., 'high' or 'low'. The degree of a term, e.g., the state of being high or low, to a given input value was determined using a membership function that converts an input value to a number between 0 and 1. The rule was evaluated by combining the degree of the terms associated with monthly climate data. Monthly risk index values derived using the rule were combined for pairs of consecutive months over 12 months. The annual risk of European canker development was represented by the maximum risk index value for 2 months combined. The membership function parameters were adjusted iteratively to achieve a specified level of risk at Talca (Chile), Loughgall (Northern Ireland), East Malling (UK), and Sebastopol (USA), where European canker risk was known. The rule-based model was validated with data collected from Canada, Ecuador, Denmark, Germany, Norway, Poland, Sweden, the Netherlands, New Zealand, and the Pacific Northwest (USA), where European canker has been reported to occur. In these validation areas, the model's risk prediction agreed with reports of disease occurrence. The rule-based model also predicted high risk areas more reliably than the climate matching model, CLIMEX, which relies on correlations between the spatial distribution of a species and climatic conditions. The combination of a climatic rule and fuzzy sets could be used for other applications where prediction of the geographic distribution of organisms is required for climatic risk assessment. PMID:21809979

Kim, Kwang Soo; Beresford, Robert M

2012-02-01

171

Three New Resveratrol Derivatives from the Mangrove Endophytic Fungus Alternaria sp.  

PubMed Central

Three new resveratrol derivatives, namely, resveratrodehydes A–C (1–3), were isolated from the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. All compounds showed broad-spectrum inhibitory activities against three human cancer cell lines including human breast MDA-MB-435, human liver HepG2, and human colon HCT-116 by MTT assay (IC50 < 50 ?M). Among them, compounds 1 and 2 both exhibited marked cytotoxic activities against MDA-MB-435 and HCT-116 cell lines (IC50 < 10 ?M). Additionally, compounds 1 and 3 showed moderate antioxidant activity by DPPH radical scavenging assay. PMID:24828291

Wang, Jinhua; Cox, Daniel G.; Ding, Weijia; Huang, Guanghao; Lin, Yongcheng; Li, Chunyuan

2014-01-01

172

Induction of defense responses against Alternaria rot by different elicitors in harvested pear fruit.  

PubMed

Pear fruit (Pyrus pyrifolia L. cv. Yali) treated by different elicitors, such as salicylic acid (SA), oxalic acid, calcium chloride, and antagonistic yeast Cryptococcus laurentii, were investigated to determine the induction of defense responses. The possible mechanism by which elicitors induced the resistance of pear fruit against postharvest disease was also evaluated. The results indicated that all the elicitors could significantly enhance defense-related enzyme activities, such as beta-1,3-glucanase, phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activity, and reduce the disease incidence caused by Alternaria alternata in pear fruit (P=0.05). Among these different elicitors, SA treatment showed the best result in inducing the defense responses and reducing the decay in pear fruit. PMID:16158285

Tian, Shiping; Wan, Yakun; Qin, Guozheng; Xu, Yong

2006-05-01

173

Metabolite profiling of Arabidopsis inoculated with Alternaria brassicicola reveals that ascorbate reduces disease severity.  

PubMed

The interaction between the pathogenic ascomycete Alternaria brassicicola and Arabidopsis was investigated by metabolite profiling. The effect of A. brassicicola challenge on metabolite levels was substantial, with nearly 50% of detected compounds undergoing significant changes. Mutations blocking ethylene, jasmonic acid, or ethylene signaling had little effect on metabolite levels. The effects of altering levels of some metabolites were tested by exogenous application during A. brassicicola inoculation. Gamma amino-butyric acid (GABA) or xylitol promoted, while trehalose and ascorbate inhibited, disease severity. GABA promoted, and ascorbate strongly inhibited, fungal growth in culture. Arabidopsis vtc1 and vtc2 mutants, that have low levels of ascorbate, were more susceptible to A. brassicicola. Ascorbate levels declined following A. brassicicola inoculation while levels of dehydroascorbate increased, resulting in a shift of the redox balance between these compounds in the direction of oxidation. These results demonstrate that ascorbate is an important component of resistance to this pathogen. PMID:23134520

Botanga, Christopher J; Bethke, Gerit; Chen, Zhong; Gallie, Daniel R; Fiehn, Oliver; Glazebrook, Jane

2012-12-01

174

Alternaria toxins alternariol and alternariol monomethyl ether in grain foods in Canada.  

PubMed

Alternaria alternata has been reported to be the most common fungus on Canadian Western wheat. The Alternaria toxins alternariol (AOH) and alternariol monomethyl ether (AME) are mutagenic in vitro and there is also limited evidence for carcinogenic properties. They have been found in wheat from Europe, Argentina, China and Australia, but they have not been looked for in Canadian grains or grain foods. In the present study, 83 samples of grain-based food sold in Canada, including flour, bran, breakfast cereals, infant cereals and bread, were analysed for AOH and AME using extraction with methanol, clean-up on combined aminopropyl/C18 solid phase extraction (SPE) columns, and liquid chromatography (LC) with tandem mass spectrometric (MS/MS) determination. The overall average recoveries of AOH and AME from a variety of spiked cereal foods (n?=?13) were 45?±?9% and 53?±?9%, which could be attributed mainly to MS matrix effects The instrumental limits of detection (LOD) were 0.34 ng/g and 0.13 ng/g for AOH and AME, respectively, and the instrumental limits of quantitation (LOQ) were 1.1 and 0.43 ng/g. Of 83 samples analysed, 70 were positive for AOH (up to 63 ng/g, in a soft wheat bran) and 64 contained AME (up to 12 ng/g in a bran-based breakfast cereal). Of particular interest was the presence of AOH and/or AME in 27 out of 30 infant foods (up to 4.4 ng/g and 9.0 ng/g, respectively, in a sample of multigrain cereal). PMID:23087499

Scott, Peter M; Zhao, Wendy; Feng, Sherry; Lau, Benjamin P-Y

2012-11-01

175

Enhancement of the citrus immune system provides effective resistance against Alternaria brown spot disease.  

PubMed

In addition to basal defense mechanisms, plants are able to develop enhanced defense mechanisms such as induced resistance (IR) upon appropriate stimulation. We recently described the means by which several carboxylic acids protect Arabidopsis and tomato plants against fungi. In this work, we demonstrate the effectiveness of hexanoic acid (Hx) in the control of Alternaria brown spot (ABS) disease via enhancement of the immune system of Fortune mandarin. The application of 1mM Hx in irrigation water to 2-year-old Fortune plants clearly reduced the incidence of the disease and led to smaller lesions. We observed that several of the most important mechanisms involved in induced resistance were affected by Hx application. Our results demonstrate enhanced callose deposition in infected plants treated with Hx, which suggests an Hx priming mechanism. Plants treated with the callose inhibitor 2-DDG were more susceptible to the fungus. Moreover, polygalacturonase-inhibiting protein (PGIP) gene expression was rapidly and significantly upregulated in treated plants. However, treatment with Hx decreased the levels of reactive oxygen species (ROS) in infected plants. Hormonal and gene analyses revealed that the jasmonic acid (JA) pathway was activated due to a greater accumulation of 12-oxo-phytodienoic acid (OPDA) and JA along with a rapid accumulation of JA-isoleucine (JA-Ile). Furthermore, we observed a more rapid accumulation of abscisic acid (ABA), which could act as a positive regulator of callose deposition. Thus, our results support the hypothesis that both enhanced physical barriers and the JA signaling pathway are involved in hexanoic acid-induced resistance (Hx-IR) to Alternaria alternata. PMID:23260526

Llorens, Eugenio; Fernández-Crespo, Emma; Vicedo, Begonya; Lapeña, Leonor; García-Agustín, Pilar

2013-01-15

176

STEM crisis or STEM surplus?  

E-print Network

The science, technology, engineering, and mathematics (STEM) workforce is a crucial driver of the U.S. economy. Over the last decade, there has been significant concern regarding the adequacy of the supply of STEM workers ...

Xue, Yi, S.M. Massachusetts Institute of Technology

2014-01-01

177

Modifications of Xanthomonas axonopodis pv. citri Lipopolysaccharide Affect the Basal Response and the Virulence Process during Citrus Canker  

PubMed Central

Xanthomonas axonopodis pv. citri (Xac) is the phytopathogen responsible for citrus canker, one of the most devastating citrus diseases in the world. A broad range of pathogens is recognized by plants through so-called pathogen-associated molecular patterns (PAMPs), which are highly conserved fragments of pathogenic molecules. In plant pathogenic bacteria, lipopolisaccharyde (LPS) is considered a virulence factor and it is being recognized as a PAMP. The study of the participation of Xac LPS in citrus canker establishment could help to understand the molecular bases of this disease. In the present work we investigated the role of Xac LPS in bacterial virulence and in basal defense during the interaction with host and non host plants. We analyzed physiological features of Xac mutants in LPS biosynthesis genes (wzt and rfb303) and the effect of these mutations on the interaction with orange and tobacco plants. Xac mutants showed an increased sensitivity to external stresses and differences in bacterial motilities, in vivo and in vitro adhesion and biofilm formation. Changes in the expression levels of the LPS biosynthesis genes were observed in a medium that mimics the plant environment. Xacwzt exhibited reduced virulence in host plants compared to Xac wild-type and Xacrfb303. However, both mutant strains produced a lower increase in the expression levels of host plant defense-related genes respect to the parental strain. In addition, Xac LPS mutants were not able to generate HR during the incompatible interaction with tobacco plants. Our findings indicate that the structural modifications of Xac LPS impinge on other physiological attributes and lead to a reduction in bacterial virulence. On the other hand, Xac LPS has a role in the activation of basal defense in host and non host plants. PMID:22792211

Petrocelli, Silvana; Tondo, María Laura; Daurelio, Lucas D.; Orellano, Elena G.

2012-01-01

178

Efficacy of heat treatment for the thousand cankers disease vector and pathogen in small black walnut logs.  

PubMed

Thousand cankers disease, caused by the walnut twig beetle (Pityophthorus juglandis Blackman) and an associated fungal pathogen (Geosmithia morbida M. Kolarík, E. Freeland, C. Utley, and N. Tisserat), threatens the health and commercial use of eastern black walnut (Juglans nigra L.), one of the most economically valuable tree species in the United States. Effective phytosanitary measures are needed to reduce the possibility of spreading this insect and pathogen through wood movement. This study evaluated the efficacy of heat treatments and debarking to eliminate P. juglandis and C. morbida in J. nigra logs 4-18 cm in diameter and 30 cm in length. Infested logs were steam heated until various outer sapwood temperatures (60, 65, and 70 degrees C in 2011; 36, 42, 48, 52, and 56 degrees C in 2012) were maintained or exceeded for 30-40 min. In 2011, all heat treatments eliminated G. morbida from the bark, but logs were insufficiently colonized by P. juglandis to draw conclusions about treatment effects on the beetle. Debarking did not ensure elimination of the pathogen from the sapwood surface. In 2012, there was a negative effect of increasing temperature on P. juglandis emergence and G. morbida recovery. G. morbida did not survive in logs exposed to treatments in which minimum temperatures were 48 degrees C or higher, and mean P. juglandis emergence decreased steadily to zero as treatment minimum temperature increased from 36 to 52 degrees C. A minimum outer sapwood temperature of 56 degrees C maintained for 40 min is effective for eliminating the thousand cankers disease vector and pathogen from walnut logs, and the current heat treatment schedule for the emerald ash borer (60 degrees C core temperature for 60 min) is more than adequate for treating P. juglandis and G. morbida in walnut firewood. PMID:24665700

Mayfield, A E; Fraedrich, S W; Taylor, A; Merten, P; Myers, S W

2014-02-01

179

A cDNA Encoding Polygalacturonase-inhibiting Protein Induced in Citrus Leaves by Polygalacturonase of Alternaria citri  

Microsoft Academic Search

  A cDNA encoding the polygalacturonase-inhibiting protein gene (RlemPGIPl) was identified from rough lemon (Citrus jambhiri Lush.). The deduced amino acid sequence is 46-75% identical to other plant PGIPs. The transcripts of the PGIP gene were weakly\\u000a but constitutively expressed in leaves and increased in leaves within 30 min after wounding or inoculation with nonpathogenic\\u000a Alternaria alternata or A. citri. However,

Yukie GOTOH; Sarunya NALUMPANG; Atsunori ISSHIKI; Takami UTSUMI; Kenji GOMI; Hiroyuki YAMAMOTO; Kazuya AKIMITSU

2002-01-01

180

Analysis of global gene expression changes in human bronchial epithelial cells exposed to spores of the allergenic fungus, Alternaria alternata.  

PubMed

Exposure and sensitivity to ubiquitous airborne fungi such as Alternaria alternata have long been implicated in the development, onset, and exacerbation of chronic allergic airway disorders. This present study is the first to investigate global changes in host gene expression during the interaction of cultured human bronchial epithelial cells and live Alternaria spores. In in vitro experiments human bronchial epithelial cells (BEAS-2B) were exposed to spores or media alone for 24 h. RNA was collected from three biological replicates per treatment and was used to assess changes in gene expression patterns using Affymetrix Human Genome U133 Plus 2.0 Arrays. In cells treated with Alternaria spores compared to controls, 613 probe sets representing 460 individual genes were found differentially expressed (p ? 0.05). In this set of 460 statistically significant, differentially expressed genes, 397 genes were found to be up-regulated and 63 were down-regulated. Of these 397 up-regulated genes, 156 genes were found to be up-regulated ?2 fold. Interestingly, none of the 63 down-regulated genes were found differentially expressed at ?-2 fold. Differentially expressed genes were identified following statistical analysis and subsequently used for pathway and network evaluation. Interestingly, many cytokine and chemokine immune response genes were up-regulated with a particular emphasis on interferon-inducible genes. Genes involved in cell death, retinoic acid signaling, and TLR3 response pathways were also significantly up-regulated. Many of the differentially up-regulated genes have been shown in other systems to be associated with innate immunity, inflammation and/or allergic airway diseases. This study now provides substantial information for further investigating specific genes and innate immune system pathways activated by Alternaria in the context of allergic airway diseases. PMID:23882263

Babiceanu, M C; Howard, B A; Rumore, A C; Kita, H; Lawrence, C B

2013-01-01

181

Survival, growth, and target canker infection of black walnut families 15 years after establishment in West Virginia. Forest Service research paper (Final)  

SciTech Connect

The survival, growth, and rate of target canker infection of 34 black walnut (Juglans nigra) families were evaluated 15 years after establishment in north-central West Virginia. The progenies originated at locations in Pennsylvania, West Virginia, Tennessee, and North Carolina. There were significant differences between families in survival, incidence of target-canker infection, total height, and diameter at breast height. The North Carolina and Tennessee sources were less suitable for the growing conditions of the test site, local and slightly more northern sources seem more suitable. Near the northern extremity of the range of black walnut, maintaining a viable native population of this species and using local seed sources in artificial regeneration activities are recommended.

Schuler, T.M.

1993-07-01

182

Quantitative Association of Bark Beetles with Pitch Canker Fungus and Effects of Verbenone on Their Semiochemical Communication in Monterey Pine Forests in Northern Spain  

Microsoft Academic Search

The association between 11 species of bark beetles (Coleoptera: Scolytinae) and one weevil (Coleoptera: Entiminae) with the pitch canker fungus, Fusarium circinatum Nirenberg and OÕDonnell, was determined by crushing beetles on selective medium and histone H3 gene sequencing. Pityophthorus pubescens (Marsham) (25.00%), Hylurgops palliatus (Gyllenhal) (11.96%), Ips sexden- tatus (Borner) (8.57%), Hypothenemus eruditus Westwood (7.89%), Hylastes attenuatus Erichson (7.40%), and

Pedro Romón; Juan Carlos Iturrondobeitia; Ken Gibson; B. Staffan Lindgren; Arturo Goldarazena

2007-01-01

183

Invasive Plants, Species and Conditions Fact Sheets: Cheatgrass Brome, Bamboo Reed, Butternut Canker, Dutch Elm, Chestnut Blight, Asian Cycad Scale, Crazy Ant, Red Fox  

NSDL National Science Digital Library

This resource from ATEEC provides a number of fact sheets on invasive plants, species and conditions which may be printed out or used as presentation material. The plants, species and conditions described here are cheatgrass brome, bamboo reed, butternut canker, dutch elm disease, chestnut blight, Asian cycad scale, crazy ant and red fox. The lesson plan is available for download as a PDF; users must create a free, quick login with ATEEC to access the materials.

2013-06-12

184

acetylcholinesterase inhibitory potential and insecticidal activity of an endophytic Alternaria sp. from Ricinus communis.  

PubMed

Keeping in view the vast potential of endophytic fungi to produce bioactive molecules, this study aimed at isolating and screening endophytes for the production of acetylcholinesterase inhibitors. Fifty-four endophytic fungi were isolated from Ricinus communis and screened for their AChE inhibitory activity using Ellman's colorimetric assay method. Six isolates were found to possess AChE inhibitory activity with maximum inhibition of 78 % being evinced by culture Cas1 which was identified to be Alternaria sp. on the basis of molecular as well as microscopic methods. Optimization of inhibitor production was carried out using one factor at a time approach. Maximum production of inhibitor was obtained on potato dextrose broth after 10 days incubation. The IC(50) of the chloroform extract was observed to be 40 ?g/ml. The extract was purified on silica gel and eluted stepwise with a gradient of chloroform/methanol. The insecticidal potential of the extract was evaluated by feeding the larvae of Spodoptera litura on diet containing varying concentrations of the extract. It was observed that with increase in the concentration of the extract, mortality of the larvae increased. The culture has the potential of being exploited in medicine as well as a biocontrol agent. PMID:22945561

Singh, Bahaderjeet; Thakur, Abhinay; Kaur, Sanehdeep; Chadha, B S; Kaur, Amarjeet

2012-11-01

185

Inhibition of Sporulation and Ultrastructural Alterations of Grapevine Downy Mildew by the Endophytic Fungus Alternaria alternata.  

PubMed

ABSTRACT One hundred twenty-six endophytic microorganisms isolated from grapevine leaves showing anomalous symptoms of downy mildew were tested on grapevine leaf disks as biocontrol agents against Plasmopara viticola. Among the 126 microorganisms, only five fungal isolates completely inhibited the sporulation of P. viticola; all of them were identified as Alternaria alternata. Ultrastructural analyses were carried out by transmission electron microscopy to observe cellular interactions between P. viticola and A. alternata in the grapevine leaf tissue. Cytological observations indicated that, even without close contact with A. alternata, the P. viticola mycelium showed severe ultrastructural alterations, such as the presence of enlarged vacuoles or vacuoles containing electron-dense precipitates. Haustoria appeared necrotic and irregularly shaped or were enclosed in callose-like substances. Therefore, a toxic action of A. alternata against P. viticola was hypothesized. To examine the production of toxic low-molecular-weight metabolites by A. alternata, we analyzed the fungal liquid culture by thin layer chromatography and proton magnetic resonance spectroscopy. The main low-molecular-weight metabolites produced by the endophyte were three diketopiperazines: cyclo(l-phenylalanine-trans-4-hydroxy-l-proline), cyclo(l-leucine-trans-4-hydroxy-l-proline), and cyclo(l-alanine-trans-4-hydroxy-l-proline). When applied at different concentrations to both grapevine leaf disks and greenhouse plants, a mixture of the three diketopiperazines was very efficacious in limiting P. viticola sporulation. PMID:18943142

Musetti, R; Vecchione, A; Stringher, L; Borselli, S; Zulini, L; Marzani, C; D'Ambrosio, M; di Toppi, L Sanità; Pertot, I

2006-07-01

186

Changes in concentration of Alternaria and Cladosporium spores during summer storms.  

PubMed

Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms. PMID:23161270

Grinn-Gofro?, Agnieszka; Strzelczak, Agnieszka

2013-09-01

187

Stress Response and Pathogenicity of the Necrotrophic Fungal Pathogen Alternaria alternata  

PubMed Central

The production of host-selective toxins by the necrotrophic fungus Alternaria alternata is essential for the pathogenesis. A. alternata infection in citrus leaves induces rapid lipid peroxidation, accumulation of hydrogen peroxide (H2O2), and cell death. The mechanisms by which A. alternata avoids killing by reactive oxygen species (ROS) after invasion have begun to be elucidated. The ability to coordinate of signaling pathways is essential for the detoxification of cellular stresses induced by ROS and for pathogenicity in A. alternata. A low level of H2O2, produced by the NADPH oxidase (NOX) complex, modulates ROS resistance and triggers conidiation partially via regulating the redox-responsive regulators (YAP1 and SKN7) and the mitogen-activated protein (MAP) kinase (HOG1) mediated pathways, which subsequently regulate the genes required for the biosynthesis of siderophore, an iron-chelating compound. Siderophore-mediated iron acquisition plays a key role in ROS detoxification because of the requirement of iron for the activities of antioxidants (e.g., catalase and SOD). Fungal strains impaired for the ROS-detoxifying system severely reduce the virulence on susceptible citrus cultivars. This paper summarizes the current state of knowledge of signaling pathways associated with cellular responses to multidrugs, oxidative and osmotic stress, and fungicides, as well as the pathogenicity/virulence in the tangerine pathotype of A. alternata. PMID:24278721

Chung, Kuang-Ren

2012-01-01

188

Multiple phytohormone signalling pathways modulate susceptibility of tomato plants to Alternaria alternata f. sp. lycopersici.  

PubMed

Three phytohormone molecules - ethylene (ET), jasmonic acid (JA) and salicylic acid (SA) - play key roles in mediating disease response to necrotrophic fungal pathogens. This study investigated the roles of the ET, JA, and SA pathways as well as their crosstalk during the interaction between tomato (Solanum lycopersicum) plants and a necrotrophic fungal pathogen Alternaria alternata f. sp. lycopersici (AAL). Both the ET and JASMONIC ACID INSENSITIVE1 (JAI1) receptor-dependent JA signalling pathways are necessary for susceptibility, while SA response promotes resistance to AAL infection. In addition, the role of JA in susceptibility to AAL is partly dependent on ET biosynthesis and perception, while the SA pathway enhances resistance to AAL and antagonizes the ET response. Based on these results, it is proposed that ET, JA, and SA each on their own can influence the susceptibility of tomato to AAL. Furthermore, the functions of JA and SA in susceptibility to the pathogen are correlated with the enhanced or decreased action of ET, respectively. This study has revealed the functional relationship among the three key hormone pathways in tomato defence against AAL. PMID:23264518

Jia, Chengguo; Zhang, Liping; Liu, Lihong; Wang, Jiansheng; Li, Chuanyou; Wang, Qiaomei

2013-01-01

189

Changes in the leaf proteome profile of Mentha arvensis in response to Alternaria alternata infection.  

PubMed

Plant pathogenic fungi cause important yield losses in crops. A proteomic approach was used to study the changes in the leaf proteome profile of the plant Mentha arvensis infected with a necrotrophic fungus, Alternaria alternata. High-resolution two-dimensional gel electrophoresis (2-DE) followed by colloidal Coomassie staining and mass spectrometric analysis was used to identify highly abundant proteins differentially expressed in response to fungal infection. From a total of 210 reproducibly detected and analyzed spots, the intensity of sixty-seven spots was altered, and forty-five of them were successfully identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry (MALDI TOF/TOF MS/MS). Fifty-six percent of the identified proteins belonged to energy and metabolism whereas 29% were stress and defense related. Taken together, the results allow to assess changes at the proteomic level in the host due to the defense response. Results show an initial defense response, not strong enough to overcome the pathogenesis, which may be similar to other susceptible plant-pathogen interactions; however, cross-talks between various defense pathways, regulatory networks and physiological conditions are other important aspects to be considered. PMID:21111074

Sinha, Ragini; Chattopadhyay, Sharmila

2011-03-01

190

Bioconversion of resveratrol using resting cells of non-genetically modified Alternaria sp.  

PubMed

Bioconversion of resveratrol is mainly achieved using plant cells and genetically modified microorganisms. We proposed a reaction system for resveratrol production using resting cells of a non-genetically modified strain, Alternaria sp. MG1, a resveratrol-producing endophytic fungus isolated from the grape. Effects of phenylalanine concentration, inoculum size, resting time, bioconversion medium, cell age, and pH on resveratrol production in the bioconversion process were investigated and their levels were optimized. The resulting optimal bioconversion medium was 0.2 mM phosphate buffer (pH 6.5), 0.1 g/L MgSO4 , 0.2 g/L CaSO4 , and 4.66 mM phenylalanine. Resting cells obtained from cultures of liquid potato-glucose medium after 4 days proved to be at the most suitable cell age for the bioconversion process with high resveratrol production and nonobvious cell growth. Highest resveratrol production (1.376 µg/L) was observed under the obtained optimal conditions of inoculum size, 12.16% (wet cell weight in 100 mL medium), and resting time, 21.3 H. The study provides a new way to produce resveratrol and establishes an essential reaction system for further study of the biosynthesis pathway of resveratrol in microorganisms, especially fungi. PMID:23586428

Zhang, Jinhua; Shi, Junling; Liu, Yanlin

2013-01-01

191

Changes in concentration of Alternaria and Cladosporium spores during summer storms  

NASA Astrophysics Data System (ADS)

Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms.

Grinn-Gofro?, Agnieszka; Strzelczak, Agnieszka

2013-09-01

192

Multiple phytohormone signalling pathways modulate susceptibility of tomato plants to Alternaria alternata f. sp. lycopersici  

PubMed Central

Three phytohormone molecules – ethylene (ET), jasmonic acid (JA) and salicylic acid (SA) – play key roles in mediating disease response to necrotrophic fungal pathogens. This study investigated the roles of the ET, JA, and SA pathways as well as their crosstalk during the interaction between tomato (Solanum lycopersicum) plants and a necrotrophic fungal pathogen Alternaria alternata f. sp. lycopersici (AAL). Both the ET and JASMONIC ACID INSENSITIVE1 (JAI1) receptor-dependent JA signalling pathways are necessary for susceptibility, while SA response promotes resistance to AAL infection. In addition, the role of JA in susceptibility to AAL is partly dependent on ET biosynthesis and perception, while the SA pathway enhances resistance to AAL and antagonizes the ET response. Based on these results, it is proposed that ET, JA, and SA each on their own can influence the susceptibility of tomato to AAL. Furthermore, the functions of JA and SA in susceptibility to the pathogen are correlated with the enhanced or decreased action of ET, respectively. This study has revealed the functional relationship among the three key hormone pathways in tomato defence against AAL. PMID:23264518

Jia, Chengguo; Zhang, Liping; Wang, Qiaomei

2013-01-01

193

STEM Thinking!  

ERIC Educational Resources Information Center

Science, Technology, Engineering, and Mathematics (STEM) is a term seen almost daily in the news. In 2009, President Obama launched the Educate to Innovate initiative to move American students from the middle to the top of the pack in science and math achievement over the next decade (The White House, n.d.). Learning about the attributes of STEM

Reeve, Edward M.

2015-01-01

194

Influence of IgG antibody and glycopeptide allergens on the correlation between the radioallergosorbent test (RAST) and skin testing or bronchial challenge with alternaria.  

PubMed Central

The radioallergosorbent test (RAST) for alternaria was compared to skin tests and bronchial challenges in children suffering from chronic intractable asthma. In contrast to when such children were tested with a timothy grass pollen extract, the bronchial challenge and skin test results against alternaria did not correlate significantly. When alternaria allergens were coupled to cyanogen bromide-activated microcrystalline cellulose, the RAST correlated with the results of skin testing but not bronchial challenge. It was demonstrated by column immunabsorption that some allergic sera contained sufficient IgG antibody against alternaria to competitively inhibit the RAST. When Sepharose 2B was substituted for cellulose as the insoluble support, the inhibition by IgG antibody was largely overcome and then the RAST correlated with both skin test and bronchial challenge results. Glycopeptides contribute significantly to the allergenicity of alternaria, and when these materials were coupled to a Sepharose 2B conjugate by mild oxidation, the RAST correlated with bronchial challenge, but not skin test, results. It was concluded that in this group of steroid-dependent asthmatic children, the correlation of the RAST with the in vivo challenges was strongly influenced by the presence of IgG antibody in the allergic sera and the chemical nature of the mould allergens investigated. PMID:765019

Lynch, N R; Dunand, P; Newcomb, R W; Chai, H; Bigley, J

1975-01-01

195

Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola  

PubMed Central

Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite. PMID:23133370

Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

2012-01-01

196

Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production  

PubMed Central

Background Although the effect of elevated carbon dioxide (CO2) concentration on pollen production has been established in some plant species, impacts on fungal sporulation and antigen production have not been elucidated. Objective Our purpose was to examine the effects of rising atmospheric CO2 concentrations on the quantity and quality of fungal spores produced on timothy (Phleum pratense) leaves. Methods Timothy plants were grown at four CO2 concentrations (300, 400, 500, and 600 ?mol/mol). Leaves were used as growth substrate for Alternaria alternata and Cladosporium phlei. The spore abundance produced by both fungi, as well as the size (microscopy) and antigenic protein content (ELISA) of A. alternata, were quantified. Results Leaf carbon-to-nitrogen ratio was greater at 500 and 600 ?mol/mol, and leaf biomass was greater at 600 ?mol/mol than at the lower CO2 concentrations. Leaf carbon-to-nitrogen ratio was positively correlated with A. alternata spore production per gram of leaf but negatively correlated with antigenic protein content per spore. At 500 and 600 ?mol/mol CO2 concentrations, A. alternata produced nearly three times the number of spores and more than twice the total antigenic protein per plant than at lower concentrations. C. phlei spore production was positively correlated with leaf carbon-to-nitrogen ratio, but overall spore production was much lower than in A. alternata, and total per-plant production did not vary among CO2 concentrations. Conclusions Elevated CO2 concentrations often increase plant leaf biomass and carbon-to-nitrogen ratio. Here we demonstrate for the first time that these leaf changes are associated with increased spore production by A. alternata, a ubiquitous allergenic fungus. This response may contribute to the increasing prevalence of allergies and asthma. PMID:20462828

Wolf, Julie; O’Neill, Nichole R.; Rogers, Christine A.; Muilenberg, Michael L.; Ziska, Lewis H.

2010-01-01

197

Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola  

SciTech Connect

Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

2012-05-01

198

Efficacy of a pyrimidine derivative to control spot disease on Solanum melongena caused by Alternaria alternata  

PubMed Central

The pyrimidine derivative (4,6-dimethyl-N-phenyldiethyl pyrimidine, DPDP) was tested as a foliar spray fungicide at 50 mg l?1 for protection of eggplant (Solanum melongena) from spot disease caused by Alternaria alternata. Varied concentrations of DPDP (10–50 mg l?1) differentially inhibited mycelial growth, conidial count and conidial germination of A. alternata growth in vitro; the magnitude of inhibition increased with increasing concentration. In vivo, an experiment was conducted in pots using a complete block randomized design and repeated twice with three replications and four treatments (control, A. alternata alone, DPDP alone and combination of DPDP and A. alternata) for 5 weeks (1 plant in pot × 3 pots per set (3 replications per treatment) × 4 sets (4 treatments) × 5 weeks × 2 experimental repetitions = 120 pots). In this experiment, 10-day-old eggplant seedlings were transplanted in pots and then inoculated with A. alternata, DPDP or their combination 1 week later. Leaves of the A. alternata-infected eggplant suffered from chlorosis, necrosis and brown spots during the subsequent 5 weeks. Disease intensity was obvious in infected leaves but withdrawn by DPDP. There were relationships between incidence and severity, greater in plant leaves infected A. alternata alone and diminished with the presence of DPDP. Moreover, the infection resulted in reductions in growth, decreases in contents of anthocyanins, chlorophylls, carotenoids and thiols as well as inhibitions in activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). Nonetheless, the application of DPDP at 50 mg led to a recovery of the infected eggplant; the infection-induced deleterious effects were mostly reversed by DPDP. However, treatment with DPDP alone seemed with no significant impacts. Due to its safe use to host and the inhibition for the pathogen, DPDP could be suggested as an efficient fungicide for protection of eggplant to control A. alternata spot disease.

Hassan, Nemat M.; Abu-Doubara, Mohamed I.; Waly, Mohamed A.; Nemat Alla, Mamdouh M.

2012-01-01

199

Contrasting Codon Usage Patterns and Purifying Selection at the Mating Locus in Putatively Asexual Alternaria Fungal Species  

PubMed Central

Sexual reproduction in heterothallic ascomycete fungi is controlled by a single mating-type locus called MAT1 with two alternate alleles or idiomorphs, MAT1-1 and MAT1-2. These alleles lack sequence similarity and encode different transcriptional regulators. A large number of phytopathogenic fungi including Alternaria spp. are considered asexual, yet still carry expressed MAT1 genes. The molecular evolution of Alternaria MAT1 was explored using nucleotide diversity, nonsynonymous vs. synonymous substitution (dn/ds) ratios and codon usage statistics. Likelihood ratio tests of site-branch models failed to detect positive selection on MAT1-1-1 or MAT1-2-1. Codon-site models demonstrated that both MAT1-1-1 and MAT1-2-1 are under purifying selection and significant differences in codon usage were observed between MAT1-1-1 and MAT1-2-1. Mean GC content at the third position (GC3) and effective codon usage (ENC) were significantly different between MAT1-1-1 and MAT1-2-1 with values of 0.57 and 48 for MAT1-1-1 and 0.62 and 46 for MAT1-2-1, respectively. In contrast, codon usage of Pleospora spp. (anamorph Stemphylium), a closely related Dothideomycete genus, was not significantly different between MAT1-1-1 and MAT1-2-1. The purifying selection and biased codon usage detected at the MAT1 locus in Alternaria spp. suggest a recent sexual past, cryptic sexual present and/or that MAT1 plays important cellular role(s) in addition to mating. PMID:21625561

Stewart, Jane E.; Kawabe, Masato; Abdo, Zaid; Arie, Tsutomu; Peever, Tobin L.

2011-01-01

200

Genetic differentiation and spatial structure of Geosmithia morbida, the causal agent of thousand cankers disease in black walnut (Juglans nigra).  

PubMed

The main objectives of this study were to evaluate genetic composition of Geosmithia morbida populations in the native range of black walnut and provide a better understanding regarding demography of the pathogen. The fungus G. morbida, and the walnut twig beetle, Pityophthorus juglandis, have been associated with a disease complex of black walnut (Juglans nigra) known as thousand cankers disease (TCD). The disease is manifested as branch dieback and canopy loss, eventually resulting in tree death. In 2010, the disease was detected in black walnut in Tennessee, and subsequently in Virginia and Pennsylvania in 2011 and North Carolina in 2012. These were the first incidences of TCD east of Colorado, where the disease has been established for more than a decade on indigenous walnut species. A genetic diversity and population structure study of 62 G. morbida isolates from Tennessee, Pennsylvania, North Carolina and Oregon was completed using 15 polymorphic microsatellite loci. The results revealed high haploid genetic diversity among seven G. morbida populations with evidence of gene flow, and significant differentiation among two identified genetic clusters. There was a significant correlation between geographic and genetic distance. Understanding the genetic composition and demography of G. morbida can provide valuable insight into recognizing factors affecting the persistence and spread of an invasive pathogen, disease progression, and future infestation predictions. Overall, these data support the hypotheses of two separate, highly diverse pathogen introductions into the native range of black walnut. PMID:24177436

Hadziabdic, Denita; Vito, Lisa M; Windham, Mark T; Pscheidt, Jay W; Trigiano, Robert N; Kolarik, Miroslav

2014-05-01

201

Bacterial canker on kiwifruit in Italy: anatomical changes in the wood and in the primary infection sites.  

PubMed

The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae is a severe threat to kiwifruit production worldwide. Many aspects of P. syringae pv. actinidiae biology and epidemiology still require in-depth investigation. The infection by and spread of P. syringae pv. actinidiae in xylem and phloem was investigated by carrying out artificial inoculation experiments with histological and dendrochronological analyses of naturally diseased plants in Italy. We found that the bacterium can infect host plants by entering natural openings and lesions. In naturally infected kiwifruit plants, P. syringae pv. actinidiae is present in the lenticels as well as in the dead phloem tissue beneath the lenticels, surrounded by a lesion in the periderm which appears to indicate the importance of lenticels to kiwifruit infection. Biofilm formation was observed outside and inside plants. In cases of advanced stages of P. syringae pv. actinidiae infection, neuroses of the phloem occur, which are followed by cambial dieback and most likely by infection of the xylem. Anatomical changes in wood such as reduced ring width, a drastic reduction in vessel size, and the presence of tyloses were observed within several infected sites. In the field, these changes occur only a year after the first leaf symptoms are observed suggesting a significant time lapse between primary and secondary symptoms. It was possible to study the temporal development of P. syringae pv. actinidiae-induced cambial dieback by applying dendrochronology methods which revealed that cambial dieback occurs only during the growing season. PMID:22713076

Renzi, Marsilio; Copini, Paul; Taddei, Anna R; Rossetti, Antonio; Gallipoli, Lorenzo; Mazzaglia, Angelo; Balestra, Giorgio M

2012-09-01

202

Purification of a Necrosis-Inducing, Host-Specific Protein Toxin from Spore Germination Fluid of Alternaria panax.  

PubMed

ABSTRACT Spore germination fluid of Alternaria panax, the causal agent of Alternaria blight of American ginseng (Panax quinquefolius), collected from water droplets or aqueous ginseng leaf extracts produced visible water-soaked lesions on wounded, detached leaflets after incubation for 48 h. Maximum development of brown, necrotic spots occurred 4 to 5 days after inoculation on attached and detached ginseng leaflets. Of 15 plant species tested, only American ginseng was susceptible to applications of spore inoculum or spore germination fluid. The phytotoxic activity of the spore germination fluid was destroyed by heat and treatment with proteinase A. The phytotoxic factor was retained by an ultrafiltration membrane with a 30-kDa molecular mass cut-off. Purification of the phytotoxic protein, named AP-toxin, was performed by anion exchange and gel filtration chromatography. Bioactive fractions eluted as a single peak. By comparison with protein standards, a molecular mass of 35 kDa was estimated for the native protein. The denatured protein toxin also had a mass of 35 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Production of the protein toxin was induced on American ginseng leaflets and water extracts of ginseng leaves but not on leaves of other nonhost plants and their water extracts. The results show that A. panax produces a host-specific, proteinaceous toxin during colonization and pathogenesis of ginseng leaves. PMID:18944342

Quayyum, H A; Gijzen, M; Traquair, J A

2003-03-01

203

Pseudomonas syringae pv. actinidiae (PSA) isolates from recent bacterial canker of kiwifruit outbreaks belong to the same genetic lineage.  

PubMed

Intercontinental spread of emerging plant diseases is one of the most serious threats to world agriculture. One emerging disease is bacterial canker of kiwi fruit (Actinidia deliciosa and A. chinensis) caused by Pseudomonas syringae pv. actinidiae (PSA). The disease first occurred in China and Japan in the 1980s and in Korea and Italy in the 1990s. A more severe form of the disease broke out in Italy in 2008 and in additional countries in 2010 and 2011 threatening the viability of the global kiwi fruit industry. To start investigating the source and routes of international transmission of PSA, genomes of strains from China (the country of origin of the genus Actinidia), Japan, Korea, Italy and Portugal have been sequenced. Strains from China, Italy, and Portugal have been found to belong to the same clonal lineage with only 6 single nucleotide polymorphisms (SNPs) in 3,453,192 bp and one genomic island distinguishing the Chinese strains from the European strains. Not more than two SNPs distinguish each of the Italian and Portuguese strains from each other. The Japanese and Korean strains belong to a separate genetic lineage as previously reported. Analysis of additional European isolates and of New Zealand isolates exploiting genome-derived markers showed that these strains belong to the same lineage as the Italian and Chinese strains. Interestingly, the analyzed New Zealand strains are identical to European strains at the tested SNP loci but test positive for the genomic island present in the sequenced Chinese strains and negative for the genomic island present in the European strains. Results are interpreted in regard to the possible direction of movement of the pathogen between countries and suggest a possible Chinese origin of the European and New Zealand outbreaks. PMID:22590555

Mazzaglia, Angelo; Studholme, David J; Taratufolo, Maria C; Cai, Rongman; Almeida, Nalvo F; Goodman, Tokia; Guttman, David S; Vinatzer, Boris A; Balestra, Giorgio M

2012-01-01

204

Occurrence of Cladosporium spp. and Alternaria spp. spores in Western, Northern and Central-Eastern Poland in 2004-2006 and relation to some meteorological factors  

NASA Astrophysics Data System (ADS)

The concentration of airborne spores of Cladosporium spp. and Alternaria spp. has been investigated at three monitoring stations situated along the west-north and central-east transect in Poland (Szczecin, Olsztyn, Warszawa,) i.e. from a height of 100 m to 149 m above sea level. The aerobiological monitoring of fungal spores was performed by means of three Lanzoni volumetric spore traps. Cladosporium spp. spores were dominant at all the stations. The highest Cladosporium spp. and Alternaria spp. numbers of spores were observed at all the cities in July and August. Statistically significant correlations have been found between the Cladosporium spp. and Alternaria spp. concentration in the air and the mean air temperature, amount of precipitation, air pressure and relative air humidity. The spore count of Cladosporium spp. and Alternaria spp. is determined by the diversity of local flora and weather conditions, especially by the air temperature. The identification of factors, which influence and shape spore concentrations, may significantly improve the current methods of allergy prevention.

Grinn-Gofro?, Agnieszka; Rapiejko, Piotr

2009-08-01

205

Expression of ß-1,3-glucanase and ß-1,4-glucanase in two potato cultivars following challenge by the fungal pathogen Alternaria solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

Early blight of potato, caused by Alternaria solani, is a ubiquitous disease in many countries around the world. We have previously found that variation in resistance phenotypes exist between two different Iranian cultivars of potato. Cultivar ‘Diamond’ is more resistant to multiple isolates of A. s...

206

Liquid chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry of the Alternaria mycotoxins alternariol and alternariol monomethyl ether in fruit juices and beverages  

Microsoft Academic Search

Alternariol (AOH) and alternariol monomethyl ether (AME) are among the main mycotoxins formed in apples and other fruits infected by Alternaria alternata. For determination of AOH and AME by LC, apple juice and other fruit beverages were cleaned up on C18 and aminopropyl solid-phase extraction columns. Positive and negative ion mass spectra of AOH and AME under electrospray (ESI) and

Benjamin P.-Y Lau; Peter M Scott; David A Lewis; Shriniwas R Kanhere; Chantal Cléroux; Veronica A Roscoe

2003-01-01

207

Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants*  

PubMed Central

The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 ?g/ml, the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P?0.079), and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P?0.001). However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 ?g/ml (P?0.096). Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Alternaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P?0.014). This result showed that the toxin-induced resistance related to the volatile changes of host plants. PMID:22302426

Yang, Fa-zhong; Li, Li; Yang, Bin

2012-01-01

208

Cell Stem Cell Stem Cell States, Fates,  

E-print Network

and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, Lund SE-223 62, Sweden 4Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, LundCell Stem Cell Review Stem Cell States, Fates, and the Rules of Attraction Tariq Enver,1 Martin

Peterson, Carsten

209

Stem cells, cancer, and cancer stem cells  

Microsoft Academic Search

Stem cell biology has come of age. Unequivocal proof that stem cells exist in the haematopoietic system has given way to the prospective isolation of several tissue-specific stem and progenitor cells, the initial delineation of their properties and expressed genetic programmes, and the beginnings of their utility in regenerative medicine. Perhaps the most important and useful property of stem cells

Tannishtha Reya; Sean J. Morrison; Michael F. Clarke; Irving L. Weissman

2001-01-01

210

Alterporriol-Type Dimers from the Mangrove Endophytic Fungus, Alternaria sp. (SK11), and Their MptpB Inhibitions  

PubMed Central

A new alterporriol-type anthranoid dimer, alterporriol S (1), along with seven known anthraquinone derivatives, (+)-aS-alterporriol C (2), hydroxybostrycin (3), halorosellinia A (4), tetrahydrobostrycin (5), 9?-hydroxydihydrodesoxybostrycin (6), austrocortinin (7) and 6-methylquinizarin (8), were isolated from the culture broth of the mangrove fungus, Alternaria sp. (SK11), from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra. The absolute configurations of 1 and the axial configuration of 2 were defined by experimental and theoretical ECD spectroscopy. 1 was identified as the first member of alterporriols consisting of a unique C-10?C-2? linkage. Atropisomer 2 exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC50 value 8.70 ?M. PMID:24840716

Xia, Guoping; Li, Jia; Li, Hanxiang; Long, Yuhua; Lin, Shao’e; Lu, Yongjun; He, Lei; Lin, Yongcheng; Liu, Lan; She, Zhigang

2014-01-01

211

Spatial and temporal distribution of Alternaria spores in the Iberian Peninsula atmosphere, and meteorological relationships: 1993-2009  

NASA Astrophysics Data System (ADS)

This paper provides an updated of airborne Alternaria spore spatial and temporal distribution patterns in the Iberian Peninsula, using a common non-viable volumetric sampling method. The highest mean annual spore counts were recorded in Sevilla (39,418 spores), Mérida (33,744) and Málaga (12,947), while other sampling stations never exceeded 5,000. The same cities also recorded the highest mean daily spore counts (Sevilla 109 spores m-3; Mérida 53 spores m-3 and Málaga 35 spores m-3) and the highest number of days on which counts exceeded the threshold levels required to trigger allergy symptoms (Sevilla 38 % and Mérida 30 % of days). Analysis of annual spore distribution patterns revealed either one or two peaks, depending on the location and prevailing climate of sampling stations. For all stations, average temperature was the weather parameter displaying the strongest positive correlation with airborne spore counts, whilst negative correlations were found for rainfall and relative humidity.

Aira, María-Jesús; Rodríguez-Rajo, Francisco-Javier; Fernández-González, María; Seijo, Carmen; Elvira-Rendueles, Belén; Abreu, Ilda; Gutiérrez-Bustillo, Montserrat; Pérez-Sánchez, Elena; Oliveira, Manuela; Recio, Marta; Tormo, Rafael; Morales, Julia

2013-03-01

212

Bioactive sulfur-containing sulochrin dimers and other metabolites from an Alternaria sp. isolate from a Hawaiian soil sample.  

PubMed

Polluxochrin (1) and dioschrin (2), two new dimers of sulochrin linked by thioether bonds, were purified from an Alternaria sp. isolate obtained from a Hawaiian soil sample. The structures of the two metabolites were established by NMR, mass spectrometry data, and X-ray analysis. Metabolite 1 was determined to be susceptible to intramolecular cyclization under aqueous conditions, resulting in the generation of 2 as well as another dimeric compound, castochrin (3). An additional nine new metabolites were also obtained, including four new pyrenochaetic acid derivatives (8-11), one new asterric acid analogue (13), and four new secalonic acid analogues (14-17). Bioassay analysis of these compounds revealed 1-3 displayed antimicrobial and weak cytotoxic activities. PMID:25265160

Cai, Shengxin; King, Jarrod B; Du, Lin; Powell, Douglas R; Cichewicz, Robert H

2014-10-24

213

Partial Resistance of Carrot to Alternaria dauci Correlates with In Vitro Cultured Carrot Cell Resistance to Fungal Exudates  

PubMed Central

Although different mechanisms have been proposed in the recent years, plant pathogen partial resistance is still poorly understood. Components of the chemical warfare, including the production of plant defense compounds and plant resistance to pathogen-produced toxins, are likely to play a role. Toxins are indeed recognized as important determinants of pathogenicity in necrotrophic fungi. Partial resistance based on quantitative resistance loci and linked to a pathogen-produced toxin has never been fully described. We tested this hypothesis using the Alternaria dauci – carrot pathosystem. Alternaria dauci, causing carrot leaf blight, is a necrotrophic fungus known to produce zinniol, a compound described as a non-host selective toxin. Embryogenic cellular cultures from carrot genotypes varying in resistance against A. dauci were confronted with zinniol at different concentrations or to fungal exudates (raw, organic or aqueous extracts). The plant response was analyzed through the measurement of cytoplasmic esterase activity, as a marker of cell viability, and the differentiation of somatic embryos in cellular cultures. A differential response to toxicity was demonstrated between susceptible and partially resistant genotypes, with a good correlation noted between the resistance to the fungus at the whole plant level and resistance at the cellular level to fungal exudates from raw and organic extracts. No toxic reaction of embryogenic cultures was observed after treatment with the aqueous extract or zinniol used at physiological concentration. Moreover, we did not detect zinniol in toxic fungal extracts by UHPLC analysis. These results suggest that strong phytotoxic compounds are present in the organic extract and remain to be characterized. Our results clearly show that carrot tolerance to A. dauci toxins is one component of its partial resistance. PMID:24983469

Voisine, Linda; Gatto, Julia; Hélesbeux, Jean-Jacques; Séraphin, Denis; Peña-Rodriguez, Luis M.; Richomme, Pascal; Boedo, Cora; Yovanopoulos, Claire; Gyomlai, Melvina; Briard, Mathilde; Simoneau, Philippe; Poupard, Pascal; Berruyer, Romain

2014-01-01

214

Dual Roles of Reactive Oxygen Species and NADPH Oxidase RBOHD in an Arabidopsis-Alternaria Pathosystem1[W  

PubMed Central

Arabidopsis (Arabidopsis thaliana) NADPH oxidases have been reported to suppress the spread of pathogen- and salicylic acid-induced cell death. Here, we present dual roles of RBOHD (for respiratory burst oxidase homolog D) in an Arabidopsis-Alternaria pathosystem, suggesting either initiation or prevention of cell death dependent on the distance from pathogen attack. Our data demonstrate that a rbohD knockout mutant exhibits increased spread of cell death at the macroscopic level upon inoculation with the fungus Alternaria brassicicola. However, the cellular patterns of reactive oxygen species accumulation and cell death are fundamentally different in the AtrbohD mutant compared with the wild type. Functional RBOHD causes marked extracellular hydrogen peroxide accumulation as well as cell death in distinct, single cells of A. brassicicola-infected wild-type plants. This single cell response is missing in the AtrbohD mutant, where infection triggers spreading-type necrosis preceded by less distinct chloroplastic hydrogen peroxide accumulation in large clusters of cells. While the salicylic acid analog benzothiadiazole induces the action of RBOHD and the development of cell death in infected tissues, the ethylene inhibitor aminoethoxyvinylglycine inhibits cell death, indicating that both salicylic acid and ethylene positively regulate RBOHD and cell death. Moreover, A. brassicicola-infected AtrbohD plants hyperaccumulate ethylene and free salicylic acid compared with the wild type, suggesting negative feedback regulation of salicylic acid and ethylene by RBOHD. We propose that functional RBOHD triggers death in cells that are damaged by fungal infection but simultaneously inhibits death in neighboring cells through the suppression of free salicylic acid and ethylene levels. PMID:19726575

Pogány, Miklós; von Rad, Uta; Grün, Sebastian; Dongó, Anita; Pintye, Alexandra; Simoneau, Philippe; Bahnweg, Günther; Kiss, Levente; Barna, Balázs; Durner, Jörg

2009-01-01

215

Stem Cells  

Microsoft Academic Search

\\u000a To fully understand the biological meaning of the term stem cell (SC) it is useful to clarify the derivation of the root staminal, even though modern research published in English-speaking journals never seem to use the term staminal. While there are\\u000a no doubts that the term SC originated in the context of two major embryological questions, the continuity of the

Manuela Monti; Carlo Alberto Redi

216

The Pro-Inflammatory but not Protective Effects of Protease-Activated-Receptor-2 In the Airways are Abolished in Beta-Arrestin-2 Mice in OVA, Cockroach Frass and Alternaria-Induced Models of Allergic Asthma.  

E-print Network

??ABSTRACT OF THE DISSERTATIONThe Pro-Inflammatory but not Protective Effects of Protease-Activated-Receptor-2 In the Airways are Abolished in Beta-Arrestin-2 Mice in OVA, Cockroach Frass and Alternaria-Induced… (more)

Nichols, Heddie

2012-01-01

217

Stem Cells and Diseases  

MedlinePLUS

... U.S. policy? More FAQs Links to related resources Stem Cell Research Center for Regenerative Medicine NIH Stem Cell Unit ... Help My Medical Condition? The International Society for Stem Cell Research (ISSCR) —ISSCR has developed information to help you ...

218

Stem Cell Transplants  

MedlinePLUS

What Are Stem Cells? As you probably remember from biology class, every living thing is made up of cells — including the human body. ... can become new cells like this. Blood Stem Cells When you hear about stem cell transplants, they ...

219

Stem Up  

NSDL National Science Digital Library

Stem Up is a pilot program to aid the disadvantaged youth of Boyle Heights in Los Angeles. The intent of the program was to integrate STEM career pathways into schools and local communities. Visitors will find the K-12 Students tab near the top of the page to be filled with almost two dozen links for all levels of student learning about science and technology. Some of the sites include "Arrick Robotics", for 9-12 graders, "Extreme Science", for all ages, and "Fun Engineering" for kids aged 10-14. The "Boyle Heights" link is a great resource for residents of the LA neighborhood, as well as informative for those visitors unfamiliar with it. There is full contact information for the city and state representatives of the neighborhood, the Police Activities League, and a live theatre that performs outreach through theatre, and classical plays. The "Parents" link also provides a number of science and technology links that parents and kids can visit together.

220

Occurrence of Cladosporium spp. and Alternaria spp. spores in Western, Northern and Central-Eastern Poland in 2004–2006 and relation to some meteorological factors  

Microsoft Academic Search

The concentration of airborne spores of Cladosporium spp. and Alternaria spp. has been investigated at three monitoring stations situated along the west-north and central-east transect in Poland (Szczecin, Olsztyn, Warszawa,) i.e. from a height of 100 m to 149 m above sea level. The aerobiological monitoring of fungal spores was performed by means of three Lanzoni volumetric spore traps.Cladosporium spp. spores were

Agnieszka Grinn-Gofron; Piotr Rapiejko

2009-01-01

221

Constitutive hydrolytic enzymes are associated with polygenic resistance of tomato to Alternaria solani and may function as an elicitor release mechanism  

Microsoft Academic Search

Foliar resistance to early blight disease of tomato, caused by the necrotrophic fungus Alternaria solani, is inherited in a complex quantitative manner. Our previous studies revealed that three moderately-resistant tomato breeding lines with different sources of early blight resistance, all possessed higher constitutive and more rapid accumulation of PR proteins, including specific antifungal isozymes of chitinase and ?-1,3-glucanase than susceptible

Christopher B. Lawrence; Narendra P. Singh; Jianseng Qiu; Randolph G. Gardner; Sadik Tuzun

2000-01-01

222

A Filamentous Hemagglutinin-Like Protein of Xanthomonas axonopodis pv. citri, the Phytopathogen Responsible for Citrus Canker, Is Involved in Bacterial Virulence  

PubMed Central

Xanthomonas axonopodis pv. citri, the phytopathogen responsible for citrus canker has a number of protein secretion systems and among them, at least one type V protein secretion system belonging to the two-partner secretion pathway. This system is mainly associated to the translocation of large proteins such as adhesins to the outer membrane of several pathogens. Xanthomonas axonopodis pv. citri possess a filamentous hemagglutinin-like protein in close vicinity to its putative transporter protein, XacFhaB and XacFhaC, respectively. Expression analysis indicated that XacFhaB was induced in planta during plant-pathogen interaction. By mutation analysis of XacFhaB and XacFhaC genes we determined that XacFhaB is involved in virulence both in epiphytic and wound inoculations, displaying more dispersed and fewer canker lesions. Unexpectedly, the XacFhaC mutant in the transporter protein produced an intermediate virulence phenotype resembling wild type infection, suggesting that XacFhaB could be secreted by another partner different from XacFhaC. Moreover, XacFhaB mutants showed a general lack of adhesion and were affected in leaf surface attachment and biofilm formation. In agreement with the in planta phenotype, adhesin lacking cells moved faster in swarming plates. Since no hyperflagellation phenotype was observed in this bacteria, the faster movement may be attributed to the lack of cell-to-cell aggregation. Moreover, XacFhaB mutants secreted more exopolysaccharide that in turn may facilitate its motility. Our results suggest that this hemagglutinin-like protein is required for tissue colonization being mainly involved in surface attachment and biofilm formation, and that plant tissue attachment and cell-to-cell aggregation are dependent on the coordinated action of adhesin molecules and exopolysaccharides. PMID:19194503

Gottig, Natalia; Garavaglia, Betiana S.; Garofalo, Cecilia G.; Orellano, Elena G.; Ottado, Jorgelina

2009-01-01

223

Quantitative association of bark beetles with pitch canker fungus and effects of verbenone on their semiochemical communication in Monterey pine forests in Northern Spain.  

PubMed

The association between 11 species of bark beetles (Coleoptera: Scolytinae) and one weevil (Coleoptera: Entiminae) with the pitch canker fungus, Fusarium circinatum Nirenberg and O'Donnell, was determined by crushing beetles on selective medium and histone H3 gene sequencing. Pityophthorus pubescens (Marsham) (25.00%), Hylurgops palliatus (Gyllenhal) (11.96%), Ips sexdentatus (Börner) (8.57%), Hypothenemus eruditus Westwood (7.89%), Hylastes attenuatus Erichson (7.40%), and Orthotomicus erosus (Wollaston) (2.73%) were found to carry the inoculum. In addition, the root weevil Brachyderes incanus L. (14.28%) had the second highest frequency of occurrence of the fungus. The responses of the insects to a range of verbenone doses were tested in field bioassays using funnel traps. Catches of P. pubescens, a species colonizing branch tips of live trees, were significantly reduced in a log-linear dose-dependent relationship. Catches of I. sexdentatus, an opportunistic species normally attacking fresh dead host material, were also gradually reduced with increasing verbenone dose. Catches of Tomicus piniperda L., O. erosus, Dryocoetes autographus (Ratzeburg), H. eruditus, Xyleborus dryographus (Ratzeburg), Hylastes ater (Paykull), Hylurgus ligniperda (F.), H. attenuatus, and B. incanus were not significantly affected by verbenone. The effects of verbenone were consistent with differences in host-age preference. Semiochemical disruption by verbenone in P. pubescens and I. sexdentatus could represent an integrated pest management strategy for the prevention of the spread of pitch canker disease between different stands. However, several species associated with F. circinatum were unaffected by verbenone, not supporting this compound for prevention of the establishment of potential vectors in Northern Spain. PMID:17716465

Romón, Pedro; Iturrondobeitia, Juan Carlos; Gibson, Ken; Lindgren, B Staffan; Goldarazena, Arturo

2007-08-01

224

Canker Sores: Treatment  

MedlinePLUS

... RAS fall roughly into four categories: occlusives, anesthetics, cleansing agents / antiseptics, and other. OTC products often combine ... with hypersensitivity. Many OTC anesthetic products are available. Cleansing agents/ Antiseptics can cleanse the area and decrease ...

225

Canker Sore (Aphthous Ulcer)  

MedlinePLUS

... or aphthae, are the most common cause of periodic (recurring) ulcers inside the mouth and genital linings ( ... Dec 2008 Information for other ages: Child Teen Table of Contents: Overview Who's At Risk Signs and ...

226

Rotatable stem and lock  

DOEpatents

A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, J.E.; Sanderson, S.N.

1981-10-27

227

Rotatable stem and lock  

DOEpatents

A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, Joseph E. (Albuquerque, NM); Sanderson, Stephen N. (Albuquerque, NM)

1984-01-01

228

Identification of a Polyketide Synthase Required for Alternariol (AOH) and Alternariol-9-Methyl Ether (AME) Formation in Alternaria alternata  

PubMed Central

Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH) and alternariol-9-methyl ether (AME) are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS). In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production. PMID:22792370

Saha, Debjani; Fetzner, Ramona; Burkhardt, Britta; Podlech, Joachim; Metzler, Manfred; Dang, Ha; Lawrence, Christopher; Fischer, Reinhard

2012-01-01

229

Selection and differentiation of Bacillus spp. Antagonistic to Fusarium oxysporum f.sp. lycopersici and Alternaria solani infecting Tomato.  

PubMed

Antagonistic Bacillus spp. displaying in vitro production of siderophore, chitinase, and ?-1,3-glucanase were identified from dual culture assays. In independent greenhouse studies, seed bacterization and soil application of Bacillus atrophaeus S2BC-2 challenge inoculated with Fusarium oxysporum f.sp. lycopersici (FOL) and Alternaria solani (AS) recorded low percent disease index of 25.3 and 28.7, respectively, over nonbacterised pathogen control (44.3 and 56.4). The low disease incidence corroborated with tomato growth promotion with high vigor index (8,041.2) and fresh plant weight (82.5 g) on challenge inoculation with FOL. Analysis of root and leaf samples in rhizobacterial treatment challenged with FOL and AS revealed maximum induction of chitinase (1.9 and 1.7 U/mg of protein, respectively) and ?-1,3-glucanase (23.5 and 19.2 U/mg of protein, respectively). In native gel activity assays, the rhizobacterial treatment on challenge inoculation strongly expressed three high intensity PO isoforms along with one low intensity isoform. In studies on genetic diversity of the Bacillus strains by repetitive extragenomic palindromic-polymerase chain reaction (REP-PCR) and amplified rDNA restriction analysis (ARDRA) patterns, ARDRA was more highly discriminant than REP-PCR and allowed grouping of the strains and differentiation of the antagonistic strains from other isolates. PMID:21503737

Shanmugam, Veerubommu; Atri, Kamini; Gupta, Samriti; Kanoujia, Nandina; Naruka, Digvijay Singh

2011-03-01

230

The phytoalexin camalexin induces fundamental changes in the proteome of Alternaria brassicicola different from those caused by brassinin.  

PubMed

Camalexin is the major phytoalexin produced by Alternaria thaliana, but is absent in Brassica species that usually produce phytoalexin blends containing brassinin and derivatives. The protein profiles of A. brassicicola treated with camalexin were evaluated using proteomics and metabolic analyses and compared with those treated with brassinin. Conidial germination and mycelial growth of A. brassicicola in liquid media amended with camalexin and brassinin showed that fungal growth was substantially slower in presence of camalexin than brassinin; chemical analyses revealed that A. brassicicola detoxified camalexin at much slower rate than brassinin. Two-dimensional gel electrophoresis (2-DE) followed by tryptic digestion and capillary liquid chromatography-mass spectrometric analyses identified 158 different proteins, of which 45 were up-regulated and 113 were down-regulated relative to controls. Venn diagram analyses of differentially expressed proteins in cultures of A. brassicicola incubated with camalexin and brassinin indicated clear differences in the effect of each phytoalexin, with camalexin causing down-regulation of a larger number of proteins than brassinin. Overall, results of this work suggest that each phytoalexin has several different targets in the cells of A. brassicicola, and that camalexin appears to have greater potential to protect cultivated Brassica species against A. brassicicola than brassinin. PMID:24433679

Pedras, M Soledade C; Minic, Zoran; Abdoli, Abbas

2014-01-01

231

Development of a stable isotope dilution LC-MS/MS method for the Alternaria toxins tentoxin, dihydrotentoxin, and isotentoxin.  

PubMed

For the Alternaria toxins tentoxin, dihydrotentoxin, and isotentoxin, a stable isotope dilution LC-MS/MS method was first developed. Triply deuterated internal standards were prepared via total synthesis and introducing the labels in the last step before cyclization. Method validation was carried out by using potato starch, tomato puree, and white pepper powder as blank matrices. For the three toxins the limits of detection ranged from 0.10 to 0.99 ?g/kg. The inter-/intraday relative standard deviations of the method were below 8.8%, and the recoveries ranged between 98 and 115%. Although cyclic peptides are known to show only negligible fragmentation, a low limit of detection was achieved with the optimization of mass spectrometry parameters and cleanup on C18-phenyl SPE columns providing a more selective binding of these phenyl-containing cyclic peptides. The method was applied to 103 food samples including bread, cereals, chips, juice, nuts, oil, sauce, seeds, and spices. Of these, 85% were contaminated with tentoxin and 55% were contaminated with dihydrotentoxin, whereas isotentoxin was not quantifiable. Maximal concentrations of tentoxin and dihydrotentoxin were 52.4 and 36.3 ?g/kg, respectively, and were both detected in paprika powder. PMID:23432357

Liu, Yang; Rychlik, Michael

2013-03-27

232

Expansion of Genetic Diversity in Randomly Mating Founder Populations of Alternaria brassicicola Infecting Cakile maritima in Australia?  

PubMed Central

Founder populations of fungal plant pathogens are expected to have low levels of genetic diversity coupled with further genetic drift due to, e.g., limited host availability, which should result in additional population bottlenecks. This study used microsatellite markers in the interaction between Cakile maritima and the fungal pathogen Alternaria brassicicola to explore genetic expectations associated with such situations. The host, C. maritima, was introduced into Australia approximately 100 years ago, but it is unknown whether the pathogen was already present in Australia, as it has a wide occurrence, or whether it was introduced to Australia on brassicaceous hosts. Eleven A. brassicicola populations were studied, and all showed moderate levels of gene and genotypic diversity. Chi-square tests of the frequencies of mating type alleles, a large number of genotypes, and linkage equilibrium among microsatellite loci all suggest A. brassicicola reproduces sexually. Significant genetic differentiation was found among populations, but there was no evidence for isolation by distance effects. Bayesian analyses identified eight clusters where the inferred clusters did not represent geographical populations but instead consisted of individuals admixed from all populations. Further analysis indicated that fungal populations were more likely to have experienced a recent population expansion than a population bottleneck. It is suggested that A. brassicicola has been introduced into Australia multiple times, potentially increasing the diversity and size of any A. brassicola populations already present there. Combined with its ability to reproduce sexually, such processes appear to have increased the evolutionary potential of the pathogen through recent population expansions. PMID:20097819

Linde, C. C.; Liles, J. A.; Thrall, P. H.

2010-01-01

233

Dehydrin-like Proteins in the Necrotrophic Fungus Alternaria brassicicola Have a Role in Plant Pathogenesis and Stress Response  

PubMed Central

In this study, the roles of fungal dehydrin-like proteins in pathogenicity and protection against environmental stresses were investigated in the necrotrophic seed-borne fungus Alternaria brassicicola. Three proteins (called AbDhn1, AbDhn2 and AbDhn3), harbouring the asparagine-proline-arginine (DPR) signature pattern and sharing the characteristic features of fungal dehydrin-like proteins, were identified in the A. brassicicola genome. The expression of these genes was induced in response to various stresses and found to be regulated by the AbHog1 mitogen-activated protein kinase (MAPK) pathway. A knock-out approach showed that dehydrin-like proteins have an impact mainly on oxidative stress tolerance and on conidial survival upon exposure to high and freezing temperatures. The subcellular localization revealed that AbDhn1 and AbDhn2 were associated with peroxisomes, which is consistent with a possible perturbation of protective mechanisms to counteract oxidative stress and maintain the redox balance in AbDhn mutants. Finally, we show that the double deletion mutant ??abdhn1-abdhn2 was highly compromised in its pathogenicity. By comparison to the wild-type, this mutant exhibited lower aggressiveness on B. oleracea leaves and a reduced capacity to be transmitted to Arabidopsis seeds via siliques. The double mutant was also affected with respect to conidiation, another crucial step in the epidemiology of the disease. PMID:24098369

Pochon, Stéphanie; Simoneau, Philippe; Pigné, Sandrine; Balidas, Samuel; Bataillé-Simoneau, Nelly; Campion, Claire; Jaspard, Emmanuel; Calmes, Benoît; Hamon, Bruno; Berruyer, Romain; Juchaux, Marjorie; Guillemette, Thomas

2013-01-01

234

RNA-Seq derived identification of differential transcription in the chrysanthemum leaf following inoculation with Alternaria tenuissima  

PubMed Central

Background A major production constraint on the important ornamental species chrysanthemum is black spot which is caused by the necrotrophic fungus Alternaria tenuissima. The molecular basis of host resistance to A. tenuissima has not been studied as yet in any detail. Here, high throughput sequencing was taken to characterize the transcriptomic response of the chrysanthemum leaf to A. tenuissima inoculation. Results The transcriptomic data was acquired using RNA-Seq technology, based on the Illumina HiSeq™ 2000 platform. Four different libraries derived from two sets of leaves harvested from either inoculated or mock-inoculated plants were characterized. Over seven million clean reads were generated from each library, each corresponding to a coverage of >350,000 nt. About 70% of the reads could be mapped to a set of chrysanthemum unigenes. Read frequency was used as a measure of transcript abundance and therefore as an identifier of differential transcription in the four libraries. The differentially transcribed genes identified were involved in photosynthesis, pathogen recognition, reactive oxygen species generation, cell wall modification and phytohormone signalling; in addition, a number of varied transcription factors were identified. A selection of 23 of the genes was transcription-profiled using quantitative RT-PCR to validate the RNA-Seq output. Conclusions A substantial body of chrysanthemum transcriptomic sequence was generated, which led to a number of insights into the molecular basis of the host response to A. tenuissima infection. Although most of the differentially transcribed genes were up-regulated by the presence of the pathogen, those involved in photosynthesis were down-regulated. PMID:24387266

2014-01-01

235

Inducible and constitutive expression of an elicitor gene Hrip1 from Alternaria tenuissima enhances stress tolerance in Arabidopsis.  

PubMed

Hrip1 is a novel hypersensitive response-inducing protein secreted by Alternaria tenuissima that activates defense responses and systemic acquired resistance in tobacco. This study investigates the role that Hrip1 plays in responses to abiotic and biotic stress using transgenic Arabidopsis thaliana expressing the Hrip1 gene under the control of the stress-inducible rd29A promoter or constitutive cauliflower mosaic virus 35S promoter. Bioassays showed that inducible Hrip1 expression in rd29A?Hrip1 transgenic lines had a significantly higher effect on plant height, silique length, plant dry weight, seed germination and root length under salt and drought stress compared to expression in 35S?Hrip1 lines and wild type plants. The level of enhancement of resistance to Botrytis cinerea by the 35S?Hrip1 lines was higher than in the rd29A?Hrip1 lines. Moreover, stress-related gene expression in the transgenic Arabidopsis lines was significantly increased by 200 mM NaCl and 200 mM mannitol treatments, and defense genes in the jasmonic acid and ethylene signaling pathway were significantly up-regulated after Botrytis inoculation in the Hrip1 transgenic plants. Furthermore, the activity of some antioxidant enzymes, such as peroxidase and catalase increased after salt and drought stress and Botrytis infection. These results suggested that the Hrip1 protein contributes to abiotic and biotic resistance in transgenic Arabidopsis and may be used as a useful gene for resistance breeding in crops. Although the constitutive expression of Hrip1 is suitable for biotic resistance, inducible Hrip1 expression is more responsive for abiotic resistance. PMID:25120219

Peng, Xue-Cong; Qiu, De-Wen; Zeng, Hong-Mei; Guo, Li-Hua; Yang, Xiu-Fen; Liu, Zheng

2015-02-01

236

The involvement of jasmonates and ethylene in Alternaria alternata f. sp. lycopersici toxin-induced tomato cell death  

PubMed Central

Previous studies have shown that an ethylene (ET)-dependent pathway is involved in the cell death signalling triggered by Alternaria alternata f. sp. lycopersici (AAL) toxin in detached tomato (Solanum lycopersicum) leaves. In this study, the role of jasmonic acid (JA) signalling in programmed cell death (PCD) induced by AAL toxin was analysed using a 35S::prosystemin transgenic line (35S::prosys), a JA-deficient mutant spr2, and a JA-insensitive mutant jai1. The results indicated that JA biosynthesis and signalling play a positive role in the AAL toxin-induced PCD process. In addition, treatment with the exogenous ET action inhibitor silver thiosulphate (STS) greatly suppressed necrotic lesions in 35S::prosys leaves, although 35S::prosys leaflets co-treated with AAL toxin and STS still have a significant high relative conductivity. Application of 1-aminocyclopropane-1-carboxylic acid (ACC) markedly enhanced the sensitivity of spr2 and jai1 mutants to the toxin. However, compared with AAL toxin treatment alone, exogenous application of JA to the ET-insensitive mutant Never ripe (Nr) did not alter AAL toxin-induced cell death. In addition, the reduced ET-mediated gene expression in jai1 leaves was restored by co-treatment with ACC and AAL toxin. Furthermore, JA treatment restored the decreased expression of ET biosynthetic genes but not ET-responsive genes in the Nr mutant compared with the toxin treatment alone. Based on these results, it is proposed that both JA and ET promote the AAL toxin-induced cell death alone, and the JAI1 receptor-dependent JA pathway also acts upstream of ET biosynthesis in AAL toxin-triggered PCD. PMID:21865178

Zhang, Liping; Jia, Chengguo; Liu, Lihong; Zhang, Zhiming; Li, Chuanyou; Wang, Qiaomei

2011-01-01

237

STEM Learning Quality Indicator Map  

E-print Network

STEM Learning Quality Indicator Map Quality Indicator Initiation Involvement Implementation Innovation Student Engagement STEM learning experiences are engaging and inspire creativity and imagination STEM learning experience is activity driven with specific step by step directions STEM learning

US Army Corps of Engineers

238

OPT STEM EXTENSION APPLICATION What is the OPT STEM Extension?  

E-print Network

OPT STEM EXTENSION APPLICATION What is the OPT STEM Extension? The OPT STEM Extension is a 17-month based on a bachelor's, master's, or Ph.D in certain STEM (Science, Technology, Engineering, Math) fields. Who is Eligible for the OPT STEM Extension? F-1 students who: 1). hold a STEM degree (see pg. 2

239

Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.  

PubMed

Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants. PMID:20552202

Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

2010-09-01

240

UW Summer STEM Undergraduate  

E-print Network

UW Summer STEM Undergraduate Research Poster SessionWednesday, August 21st, 2013 9:00 am--12 noon to conduct research in STEM fields. For more information, contact the Undergraduate Research Program at: urp

Kaminsky, Werner

241

Hematopoietic Stem Cell Transplantation  

Microsoft Academic Search

\\u000a The purpose of hematopoietic stem cell transplantation (HSCT) is to replace diseased, damaged, or absent hematopoietic stem\\u000a cells (HSCs) with healthy HSCs. In general, allogeneic transplants are used when the hematopoietic stem cells are diseased\\u000a (e.g., leukemia), damaged (e.g., sickle cell disease), or absent (e.g., severe immunodeficiency disease). Autologous transplants\\u000a are used to provide stem cell rescue after higher doses

Robbie Norville; Deborah Tomlinson

242

Stem Cell Basics  

MedlinePLUS

... U.S. policy? More FAQs Links to related resources Stem Cell Research Center for Regenerative Medicine NIH Stem Cell Unit ... of scientific research, and the potential use of stem cells in research and in treating disease. The primer includes information ...

243

Understanding Embryonic Stem Cells  

NSDL National Science Digital Library

This indexed webcast video along with synchronized lecture slides is from Howard Hughes Medical Institute's 2006 Holiday LecturesPotent Biology: Stem Cells, Cloning, and Regeneration. Douglas A. Melton presents an introduction to stem cells, as well as answers to questions about the role of stem cells in the human body. This video requires RealPlayer 10.

Douglas A. Melton, Ph.D. (Howard Hughes Medical Institute; )

2008-04-10

244

Understanding STEM: Current Perceptions  

ERIC Educational Resources Information Center

In many ways, the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness. The proponents of STEM education believe that by increasing math and science requirements in…

Brown, Ryan; Brown, Joshua; Reardon, Kristin; Merrill, Chris

2011-01-01

245

STEM Bridge Scholarship Program  

E-print Network

2015-2016 STEM Bridge Scholarship Program Virginia Space Grant Consortium (VSGC) provides renewable STEM Bridge Scholarships of $1,000 to sophomore students from any federally recognized minority group enrolled full-time in a program of study in science, technology, engineering, or math (STEM) at one

Buehrer, R. Michael

246

Stem Cell Quick Guide: Stem Cell Basics What is a Stem Cell?  

E-print Network

Stem Cell Quick Guide: Stem Cell Basics What is a Stem Cell? Stem cells are the starting point from to line blood vessels. All of these highly specialized cells have to grow from unspecialized stem cells. Stem cells produce new cells by dividing. In the right conditions, these new cells can then continue

Schladow, S. Geoffrey

247

Embryonic stem cells. Stem cell programs.  

PubMed

The availability of human embryonic stem cell lines provides an important tool for scientists to explore the fundamental mechanisms that regulate differentiation into specific cell types. When more is known about the mechanisms that govern these processes, human embryonic stem cells may be clinically useful in generating cell types that have been damaged or depleted by a variety of human diseases. The NIH is actively pursuing a variety of initiatives to promote this developing research field, while continuing and expanding its long-standing investment in adult stem cells and research. PMID:12738840

Zerhouni, Elias

2003-05-01

248

Stem Cell 101 What is a stem cell?  

E-print Network

and stem cells found in the skin generally form skin. However, some research suggests that certain adultStem Cell 101 What is a stem cell? A stem cell is a parent cell in the body that has two specific into all types of tissue in the body ­ this is called differentiation. Where are stem cells found

Minnesota, University of

249

Stem Cell Transplants  

NSDL National Science Digital Library

Transplanting embryonic stem cells from embryo into adult as a means of rejuvenating diseased cells, tissues, and organs poses ethical and moral challenges. In recent years, stem cell-derived nerve and glandular tissue has been transplanted into the brains and pancreas of Parkinson's disease and diabetes patients, respectively, with mixed results. This chapter provides background information on stem cell research, the future treatment of Parkinson's disease, and the controversy surrounding this sensitive issue.

Irwin Slesnick

2004-01-01

250

Embryonic Stem Cell Course  

NSDL National Science Digital Library

This "Course-in-a-Box" from Bio-Link is a good starting point for instructors to develop a course on embryonic stem cells. If a full course on stem cells is not appropriate for a particular curriculum "individual lectures and activity modules are well-suited for integration into existing bioscience or biotechnology courses." Materials include laboratory protocols for both mouse and human embryonic stem cells, lectures, activities, and assessments. A free login is required to access the materials.

251

Stem Cell Resources  

NSDL National Science Digital Library

The mission of the Stem Cell Resources website is "to provide timely, reliable, high-quality and scientifically credible stem cell information for the educational community worldwide." The website is a division of Bioscience Network which publishes online science education materials. On the site, visitors will find a stem cell image library, a multimedia area, and a special section titled "For Educators". In the "For Educators" area, visitors will find links to a primer on stem cells and links to educational resources on stem cells from curriculum to case studies to lesson plans from such trusted sources as the Australian Stem Cell Centre and the National Institutes of Health. Moving on, the "Multimedia" area includes videos that show how embryonic stem cell lines are made, along with other animations and graphics on the topic. Additionally, the site's "SCR Library" area includes the link to the Stem Cell Image Library, which provides dozens of photos of stem cells taken from researchers at the University of Cambridge and other institutions.

252

Stem cells and reproduction  

PubMed Central

Purpose of review To review the latest developments in reproductive tract stem cell biology. Recent findings In 2004, two studies indicated that ovaries contain stem cells which form oocytes in adults and that can be cultured in vitro into mature oocytes. A live birth after orthotopic transplantation of cyropreserved ovarian tissue in a woman whose ovaries were damaged by chemotherapy demonstrates the clinical potential of these cells. In the same year, another study provided novel evidence of endometrial regeneration by stem cells in women who received bone marrow transplants. This finding has potential for the use in treatment of uterine disorders. It also supports a new theory for the cause of endometriosis, which may have its origin in ectopic transdifferentiation of stem cells. Several recent studies have demonstrated that fetal cells enter the maternal circulation and generate microchimerism in the mother. The uterus is a dynamic organ permeable to fetal stem cells, capable of transdifferentiation and an end organ in which bone marrow stem cells may differentiate. Finally stem cell transformation can be an underlying cause of ovarian cancer. Summary Whereas we are just beginning to understand stem cells, the potential implications of stem cells to reproductive biology and medicine are apparent. PMID:20305558

Du, Hongling; Taylor, Hugh S.

2011-01-01

253

Stress and stem cells  

PubMed Central

The unique properties and functions of stem cells make them particularly susceptible to stresses and also lead to their regulation by stress. Stem cell division must respond to the demand to replenish cells during normal tissue turnover as well as in response to damage. Oxidative stress, mechanical stress, growth factors, and cytokines signal stem cell division and differentiation. Many of the conserved pathways regulating stem cell self-renewal and differentiation are also stress-response pathways. The long life span and division potential of stem cells create a propensity for transformation (cancer) and specific stress responses such as apoptosis and senescence act as antitumor mechanisms. Quiescence regulated by CDK inhibitors and a hypoxic niche regulated by FOXO transcription factor function to reduce stress for several types of stem cells to facilitate long-term maintenance. Aging is a particularly relevant stress for stem cells, because repeated demands on stem cell function over the life span can have cumulative cell-autonomous effects including epigenetic dysregulation, mutations, and telomere erosion. In addition, aging of the organism impairs function of the stem cell niche and systemic signals, including chronic inflammation and oxidative stress. PMID:23799624

Tower, John

2013-01-01

254

Stemming vision loss with stem cells.  

PubMed

Dramatic advances in the field of stem cell research have raised the possibility of using these cells to treat a variety of diseases. The eye is an excellent target organ for such cell-based therapeutics due to its ready accessibility, the prevalence of vasculo- and neurodegenerative diseases affecting vision, and the availability of animal models to demonstrate proof of concept. In fact, stem cell therapies have already been applied to the treatment of disease affecting the ocular surface, leading to preservation of vision. Diseases in the back of the eye, such as macular degeneration, diabetic retinopathy, and inherited retinal degenerations, present greater challenges, but rapidly emerging stem cell technologies hold the promise of autologous grafts to stabilize vision loss through cellular replacement or paracrine rescue effects. PMID:20811157

Marchetti, Valentina; Krohne, Tim U; Friedlander, David F; Friedlander, Martin

2010-09-01

255

Stemming vision loss with stem cells  

PubMed Central

Dramatic advances in the field of stem cell research have raised the possibility of using these cells to treat a variety of diseases. The eye is an excellent target organ for such cell-based therapeutics due to its ready accessibility, the prevalence of vasculo- and neurodegenerative diseases affecting vision, and the availability of animal models to demonstrate proof of concept. In fact, stem cell therapies have already been applied to the treatment of disease affecting the ocular surface, leading to preservation of vision. Diseases in the back of the eye, such as macular degeneration, diabetic retinopathy, and inherited retinal degenerations, present greater challenges, but rapidly emerging stem cell technologies hold the promise of autologous grafts to stabilize vision loss through cellular replacement or paracrine rescue effects. PMID:20811157

Marchetti, Valentina; Krohne, Tim U.; Friedlander, David F.; Friedlander, Martin

2010-01-01

256

Application of Plackett-Burman experimental design and Doehlert design to evaluate nutritional requirements for xylanase production by Alternaria mali ND-16.  

PubMed

The objective of this study was to use statistically based experimental designs for the optimization of xylanase production from Alternaria mali ND-16. Ten components in the medium were screened for nutritional requirements. Three nutritional components, including NH(4)Cl, urea, and MgSO(4), were identified to significantly affect the xylanase production by using the Plackett-Burman experimental design. These three major components were subsequently optimized using the Doehlert experimental design. By using response surface methodology and canonical analysis, the optimal concentrations for xylanase production were: NH(4)Cl 11.34 g L(-1), urea 1.26 g L(-1), and MgSO(4) 0.98 g L(-1). Under these optimal conditions, the xylanase activity from A. mali ND-16 reached 30.35 U mL(-1). Verification of the optimization showed that xylanase production of 31.26 U mL(-1) was achieved. PMID:17846761

Li, Yin; Liu, Zhiqiang; Cui, Fengjie; Liu, Zhisheng; Zhao, Hui

2007-11-01

257

Azole-synergistic anti-candidal activity of altenusin, a biphenyl metabolite of the endophytic fungus Alternaria alternata isolated from Terminalia chebula Retz.  

PubMed

In this study, a tropical endophytic fungus, Alternaria alternata Tche-153 was isolated from a Thai medicinal plant Terminalia chebula Rezt. The ethyl acetate extract prepared from the fermentation broth exhibited significant ketoconazole-synergistic activity against Candida albicans. Bioassay-directed fractionation of the ethyl acetate extract led to the isolation of altenusin (1), isoochracinic acid (2), and altenuic acid (3) together with 2,5-dimethyl-7-hydroxychromone (4). Using the disc diffusion method and the microdilution chequerboard technique, only altenusin (1) in combination with each of three azole drugs, ketoconazole, fluconazole or itraconazole at their low sub-inhibitory concentrations exhibited potent synergistic activity against C. albicans with the fractional inhibitory concentration index range of 0.078 to 0.188. This first discovery of altenusin (1) as a new azole-synergistic prototype possessing a biphenyl structure is of significance for further development of new azole-synergists to treat invasive candidiasis. PMID:24385360

Phaopongthai, Jatuporn; Wiyakrutta, Suthep; Meksuriyen, Duangdeun; Sriubolmas, Nongluksna; Suwanborirux, Khanit

2013-12-01

258

Multiple Epoxide Hydrolases in Alternaria alternata f. sp. lycopersici and Their Relationship to Medium Composition and Host-Specific Toxin Production  

PubMed Central

The production of Alternaria alternata f. sp. lycopersici host-specific toxins (AAL toxins) and epoxide hydrolase (EH) activity were studied during the growth of this plant-pathogenic fungus in stationary liquid cultures. Media containing pectin as the primary carbon source displayed peaks of EH activity at day 4 and at day 12. When pectin was replaced by glucose, there was a single peak of EH activity at day 6. Partial characterization of the EH activities suggests the presence of three biochemically distinguishable EH activities. Two of them have a molecular mass of 25 kDa and a pI of 4.9, while the other has a molecular mass of 20 kDa and a pI of 4.7. Each of the EH activities can be distinguished by substrate preference and sensitivity to inhibitors. The EH activities present at day 6 (glucose) or day 12 (pectin) are concomitant with AAL toxin production. PMID:10347018

Morisseau, Christophe; Ward, Barney L.; Gilchrist, David G.; Hammock, Bruce D.

1999-01-01

259

Bioreactors Stem Cells  

E-print Network

Keywords Bioreactors Stem Cells Regenerative Medicine Tissue Engineering Pharmacology » Prof. M.; yeZhelyev, M.; eMMrich, F.; o'regan, r.; bader, a. Quantum dots for human mesenchymal stem cells in situ tracheal regeneration: the bionic tissue engineered transplantation approach. J Cell Mol Med. Jul

Schüler, Axel

260

Bringing STEM to Life  

ERIC Educational Resources Information Center

The interdisciplinary approach that science, technology, engineering and mathematics (STEM) projects inspire in both teachers and students "brings to light a larger picture that promotes real-world scientific applications, which has in turn been shown to increase undergraduate persistence in STEM." The high school students have been warned…

Berkeihiser, Mike; Ray, Dori

2013-01-01

261

Valve stem seal  

Microsoft Academic Search

A fixed valve stem oil seal for a piston-type internal combustion engine is described, comprising: a cup-shaped case having a radially extending flange with a central aperture for the acceptance of a valve stem and an axially extending portion positively engageable with a valve guide, and a seal element disposed between the radial flange on the case and the valve

B. F. Rericha; B. G. Stritzke

1989-01-01

262

Hematopoietic stem cell transplantation  

PubMed Central

More than 25,000 hematopoietic stem cell transplantations (HSCTs) are performed each year for the treatment of lymphoma, leukemia, immune-deficiency illnesses, congenital metabolic defects, hemoglobinopathies, and myelodysplastic and myeloproliferative syndromes. Before transplantation, patients receive intensive myeloablative chemoradiotherapy followed by stem cell “rescue.” Autologous HSCT is performed using the patient’s own hematopoietic stem cells, which are harvested before transplantation and reinfused after myeloablation. Allogeneic HSCT uses human leukocyte antigen (HLA)-matched stem cells derived from a donor. Survival after allogeneic transplantation depends on donor–recipient matching, the graft-versus-host response, and the development of a graft versus leukemia effect. This article reviews the biology of stem cells, clinical efficacy of HSCT, transplantation procedures, and potential complications. PMID:24198516

Hatzimichael, Eleftheria; Tuthill, Mark

2010-01-01

263

I-STEM  

NSDL National Science Digital Library

The University of Illinois at Urbana-Champaign has developed a multi-pronged approach to remedying the lack of academic emphasis on the STEM subjects, from preschool through college, as well as the lack of interest in STEM subjects on the part of youth in the United States. Visitors can read about the University's four goals under the "Goals" tab at the top of any page. The "STEM Ed Projects" tab contains a directory of externally funded projects divided into four categories, and which are then further divided into subcategories. Visitors will find such projects as "Improving Supply and Demand Data for the Preparation of Secondary Science and Math Teachers" and "Clean Energy Education Workshop", under the category that aims to shape policy and advocate for STEM education. The "Resources" tab contains half a dozen categories under which visitors will find Outreach Resources, Teacher Development and Resources, and Policy and Advocacy for STEM Ed.

264

Intraoperative Stem Cell Therapy  

PubMed Central

Stem cells hold significant promise for regeneration of tissue defects and disease-modifying therapies. Although numerous promising stem cell approaches are advancing in clinical trials, intraoperative stem cell therapies offer more immediate hope by integrating an autologous cell source with a well-established surgical intervention in a single procedure. Herein, the major developments in intraoperative stem cell approaches, from in vivo models to clinical studies, are reviewed, and the potential regenerative mechanisms and the roles of different cell populations in the regeneration process are discussed. Although intraoperative stem cell therapies have been shown to be safe and effective for several indications, there are still critical challenges to be tackled prior to adoption into the standard surgical armamentarium. PMID:22809140

Coelho, Mónica Beato; Cabral, Joaquim M.S.; Karp, Jeffrey M.

2013-01-01

265

Cell Stem Cell Molecular Analysis of Stem Cells and Their  

E-print Network

homeostasis and regeneration, but also the utility of studies in planarians to broadly inform stem cellCell Stem Cell Article Molecular Analysis of Stem Cells and Their Descendants during Cell Turnover@neuro.utah.edu DOI 10.1016/j.stem.2008.07.002 SUMMARY In adult planarians, the replacement of cells lost

Alvarado, Alejandro Sánchez

266

Cell Stem Cell Control of Stem Cell Fate by Physical  

E-print Network

, Philadelphia, PA 19104, USA 5Stem Cell Laboratory, Pennington Biomedical Research Center, Louisiana StateCell Stem Cell Review Control of Stem Cell Fate by Physical Interactions with the Extracellular.06.016 A diverse array of environmental factors contributes to the overall control of stem cell activity

Chen, Christopher S.

267

Cell Stem Cell Stem Cell Epigenetics: Looking Forward  

E-print Network

Cell Stem Cell Voices Stem Cell Epigenetics: Looking Forward Epigenetics in Adult SCs The integrity of tissues is maintained by adult stem cells during adulthood. How- ever, recent work indicates that tissues often contain more than one population of stem cells that are located at distinct niches and display

Sander, Maike

268

``Stemness'': Transcriptional Profiling of Embryonic and Adult Stem Cells  

Microsoft Academic Search

The transcriptional profiles of mouse embryonic, neural, and hematopoietic stem cells were compared to define a genetic program for stem cells. A total of 216 genes are enriched in all three types of stem cells, and several of these genes are clustered in the genome. When compared to differentiated cell types, stem cells express a significantly higher number of genes

Miguel Ramalho-Santos; Soonsang Yoon; Yumi Matsuzaki; Richard C. Mulligan; Douglas A. Melton

2002-01-01

269

Nuclear receptor regulation of stemness and stem cell differentiation  

PubMed Central

Stem cells include a diverse number of toti-, pluri-, and multi-potent cells that play important roles in cellular genesis and differentiation, tissue development, and organogenesis. Genetic regulation involving various transcription factors results in the self-renewal and differentiation properties of stem cells. The nuclear receptor (NR) superfamily is composed of 48 ligand-activated transcription factors involved in diverse physiological functions such as metabolism, development, and reproduction. Increasing evidence shows that certain NRs function in regulating stemness or differentiation of embryonic stem (ES) cells and tissue-specific adult stem cells. Here, we review the role of the NR superfamily in various aspects of stem cell biology, including their regulation of stemness, forward- and trans-differentiation events; reprogramming of terminally differentiated cells; and interspecies differences. These studies provide insights into the therapeutic potential of the NR superfamily in stem cell therapy and in treating stem cell-associated diseases (e.g., cancer stem cell). PMID:19696553

Jeong, Yangsik

2009-01-01

270

Autophagy in stem cells  

PubMed Central

Autophagy is a highly conserved cellular process by which cytoplasmic components are sequestered in autophagosomes and delivered to lysosomes for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis as well as remodeling during normal development, and dysfunctions in autophagy have been associated with a variety of pathologies including cancer, inflammatory bowel disease and neurodegenerative disease. Stem cells are unique in their ability to self-renew and differentiate into various cells in the body, which are important in development, tissue renewal and a range of disease processes. Therefore, it is predicted that autophagy would be crucial for the quality control mechanisms and maintenance of cellular homeostasis in various stem cells given their relatively long life in the organisms. In contrast to the extensive body of knowledge available for somatic cells, the role of autophagy in the maintenance and function of stem cells is only beginning to be revealed as a result of recent studies. Here we provide a comprehensive review of the current understanding of the mechanisms and regulation of autophagy in embryonic stem cells, several tissue stem cells (particularly hematopoietic stem cells), as well as a number of cancer stem cells. We discuss how recent studies of different knockout mice models have defined the roles of various autophagy genes and related pathways in the regulation of the maintenance, expansion and differentiation of various stem cells. We also highlight the many unanswered questions that will help to drive further research at the intersection of autophagy and stem cell biology in the near future. PMID:23486312

Guan, Jun-Lin; Simon, Anna Katharina; Prescott, Mark; Menendez, Javier A.; Liu, Fei; Wang, Fen; Wang, Chenran; Wolvetang, Ernst; Vazquez-Martin, Alejandro; Zhang, Jue

2013-01-01

271

Stem Cell Differentiation Game  

NSDL National Science Digital Library

This game uses a modified Uno deck to review concepts related to stem cell research and diabetes. Specifically, it covers material in the "Pulse-Chase Primer," "Pancreatic Beta Cells," and "Microarrays and Stem Cells" activities from the same resource which may or may not be necessary to complete prior to this activity (depending on learner's prior knowledge). Learners accumulate points and answer questions about stem cells, development, and microarrays so that they can be the first to differentiate into a pancreatic beta (?) cell. This activity is recommended for learners studying Biology at the High School (honors, IB and AP) or Undergraduate level.

Mary Colvard

2010-01-01

272

Stem Cell Task Force  

NSDL National Science Digital Library

This Web site from the National Institutes of Health (NIH) provides an overview of the activities of an NIH task force established to move the stem cell research agenda forward. The section titled Scientific Research may be of particular interest to researchers in this area. It provides links to the Web sites of stem cell-related research at a number of NIH institutes, as well as an extensive information index, a FAQs page about stem cell research, information on funding opportunities, and much more.

273

Prostate cancer stem cells  

PubMed Central

Despite the discovery over 60 years ago by Huggins and Hodges 1 that prostate cancers respond to androgen deprivation therapy, hormone-refractory prostate cancer remains a major clinical challenge. There is now mounting evidence that solid tumours originate from undifferentiated stem cell-like cells coexisting within a heterogeneous tumour mass that drive tumour formation, maintain tumour homeostasis and initiate metastases. This review focuses upon current evidence for prostate cancer stem cells, addressing the identification and properties of both normal and transformed prostate stem cells. PMID:19040209

Lang, SH; Frame, FM; Collins, AT

2009-01-01

274

LESSON PLAN Stem Cell Discussion  

E-print Network

of stem cell research · research the current research situation · debate the future of stem cell of the ethical, moral and social implications of stem cell research. Photocopy these pages and distribute to students to read. · Make a list of advantages and disadvantages of using embryonic stem cells in research

Rambaut, Andrew

275

Information on Stem Cell Research  

MedlinePLUS

Information on Stem Cell Research Research @ NINDS Stem Cell Highlights Submit a hESC line for NIH review (9/21/09) NIH Opens Website ... found here: Human Induced Pluripotent Stem Cells NINDS Stem Cell Research on Campus The Intramural Research Program of NINDS ...

276

The advantages of hair follicle pluripotent stem cells over embryonic stem cells and induced pluripotent stem cells for regenerative medicine  

Microsoft Academic Search

Multipotent adult stem cells have many potential therapeutic applications. Our recent findings suggest that hair follicles are a promising source of easily accessible multipotent stem cells. Stem cells in the hair follicle area express the neural stem cell marker nestin, suggesting that hair-follicle stem cells and neural stem cells have common features. Nestin-expressing hair follicle stem cells can form neurons

Yasuyuki Amoh; Kensei Katsuoka; Robert M. Hoffman

2010-01-01

277

Stem cells and solid cancers.  

PubMed

Recently, there have been significant advances in our knowledge of stem cells found in tissues that can develop solid tumours. In particular, novel stem cell markers have been identified for the first time identifying multipotential cells: a required characteristic of a stem cell. The scarcity of cancer stem cells has been questioned. Current dogma states that they are rare, but novel research has suggested that this may not be the case. Here, we review the latest literature on stem cells, particularly cancer stem cells within solid tumours. We discuss current thinking on how stem cells develop into cancer stem cells and how they protect themselves from doing so and do they express unique markers that can be used to detect stem cells. We attempt to put into perspective these latest advances in stem cell biology and their potential for cancer therapy. PMID:19499244

McDonald, Stuart A C; Graham, Trevor A; Schier, Stefanie; Wright, Nicholas A; Alison, Malcolm R

2009-07-01

278

STEM Careers Grad Students  

NSDL National Science Digital Library

This brief video from WPSU introduces a diverse group of graduate students with interests in STEM careers. From deep sea diving to creating video games, each graduate student is pursuing activities beyond the stereotypical view of a nerdy scientist.

Wpsu

2009-11-10

279

Springboard to STEM  

NSDL National Science Digital Library

The goal of the Springboard to STEM program is "to increase student interest in science, technology, engineering and mathematics (STEM) and provide training and classroom materials for teachers." On this website, visitors can take advantage of free educational materials like worksheets, lesson plans, and discussion questions. Visitors need to fill out a form on the site before they can access all of the materials, but this only takes a minute or two. Moving on, the News and Links area contains links to their work around STEM education and the project's Twitter feed. The Marketplace is another great feature of the site which contains links to high quality STEM-related resources, such as books and classroom DVDs, that are available for purchase.

280

STEM Careers Middle School  

NSDL National Science Digital Library

This brief video from WPSU introduces a diverse group of middle school students with interests in STEM careers. Whether creating robots or designing solar cars, each student dreams of activities beyond the stereotypical view of a nerdy scientist.

WPSU

2009-11-10

281

Prostate cancer stem cells  

PubMed Central

The Cancer Stem Cells (CSCs) hypothesis postulates that a minute subpopulation of cells is accountable for cancer initiation and progression. Unlike the stochastic and clonal evolution models, the CSC theory proposes that tumours are hierarchical and only the rare subset of cells at the top of the 'stemness hierarchy tree’ are adequately ‘equipped’ biologically to initiate and drive tumourigenesis. CSCs have been implicated in various solid malignancies including prostate cancer (PCa), where their existence seems to provide an explanation for the failure of tumour eradicating therapies. As CSCs are thought to share many properties with normal stem cells, understanding normal stem cells should shed light on the pathomechanisms of cancer and, importantly, on potential therapeutic interventions. The purpose of this paper is to review the existing data on CSCs in PCa, their putative phenotypic markers, potential role in tumour biology and relevance to therapy. PMID:24578892

Abel, Paul

2011-01-01

282

Control of Stemness by Fibroblast Growth Factor Signaling in Stem Cells and Cancer Stem Cells  

Microsoft Academic Search

Since the discovery of stem cells, scientists have invested tremendous effort in establishing in vitro culture conditions in order to maintain the self-renewal and efficient proliferative capabilities of stem cells by manipulating a va- riety of growth factors. Fibroblast growth factor (FGF) is one of the most common growth factors used to expand stem cells, including human embryonic stem (hES)

Noriko Gotoh

2009-01-01

283

Hematopoietic stem cell donation.  

PubMed

Allogeneic hematopoietic stem cell transplantation is now an important treatment for numerous diseases. Donation of hematopoietic stem cells, either through bone marrow (BM) harvesting or peripheral blood stem cell (PBSC) collection, is a well-established and generally accepted procedure. The BM is aspirated from the posterior iliac crest under spinal or general anesthesia, and common side effects include fatigue and local pain. PBSC collection requires 4-6 days of G-CSF injections and leukapheresis 1-2 times. Common side effects of these procedures include bone pain, fatigue, and headache. The side effects of BM and PBSC collections are mostly transient and well tolerated. Severe adverse events are uncommon in healthy donors. At present, there is no definitive evidence to show that the stem cell donation increases the risk of marrow failure or cancer development. Nevertheless, all donors must be carefully evaluated and fully informed before donation. Donors must be able to provide informed consent without being coerced or pressured. Donors and graft products must be examined for potential agents to avoid transmitting infections and other diseases that may jeopardize donor's health during stem cell collection or recipient's well being after transplantation. Understanding the potential physical and psychological complications of stem cell donation and factors that may increase risks is very important to ensure that transplantation physicians maintain positive attitude in conducting this benevolent practice. PMID:23420184

Chen, Shu-Huey; Wang, Tso-Fu; Yang, Kuo-Liang

2013-04-01

284

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Wordin, J.J.

1991-09-03

285

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, John J. (Bingham County, ID)

1991-01-01

286

Fifth Annual Stem Cell Summit.  

PubMed

The Fifth Annual Stem Cell Summit, held in New York, included topics covering new commercial developments in the research field of stem cell-based therapies. This conference report highlights selected presentations on embryonic and adult stem cells, stem cell-based therapies for the treatment of orthopedic and cardiovascular indications and inflammatory diseases, as well as technologies for processing and storing stem cells. Investigational therapies discussed include placental expanded (PLX) cells (Pluristem Therapeutics Inc), StemEx (Gamida-Teva Joint Venture/Teva Pharmaceutical Industries Ltd) and remestemcel-L (Osiris Therapeutics Inc/Genzyme Corp/JCR Pharmaceuticals Co Ltd/ Mochida Pharmaceutical Co Ltd). PMID:20373251

Knowlton, Daniel

2010-04-01

287

STEM Guitar Project  

NSDL National Science Digital Library

This ATE professional development project is a collaboration between STEM faculty teams from Butler County Community College (Butler, PA), Purdue University (West Lafayette, IN), Sinclair Community College (Dayton, OH), Ventura College (Ventura, CA), College of the Redwoods (Eureka, Ca.), as well as high school STEM faculty in each of the states involved. Faculty teams at the respective locations are working together to design, build, and analyze solid body electric guitars as a means of learning applied concepts of science, technology, engineering, mathematics, and as a means of understanding product lifecycle management. This experience is providing teachers and students an accurate simulation of the collaborative design and rapid manufacturing processes routinely used in business and industry. Over 150 STEM faculty members from high schools and community colleges are participating in an intense five-day Summer Professional Development Program and are having extensive academic year follow-up activities. The teacher participants are using these processes and simulations in their classrooms to enhance the STEM laboratory learning experience. Nearly 5000 students are learning about cross-disciplinary STEM problem solving that is becoming increasingly important for new design technicians to experience.On the site, visitors can find curriculum materials including classroom tools and information on guitar fabrication. There are also details of upcoming workshops and professional development opportunities. In the Storefront section, visitors can learn about how to purchase a guitar kit.

2010-09-15

288

5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE, (12' DIAMETER HARDESTY MODEL 112 CIRCULAR GATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Island Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

289

6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (18' HARDESTY GATE), LOOKING SOUTHEAST - High Mountain Dams in Bonneville Unit, Long Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

290

7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (15' HARDESTY MODEL 115 GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Marjorie Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

291

5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (28' WIDE HARDESTY CAST IRON SLIDE HEADGATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Duck Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

292

7. VIEW OF UPRIGHT OUTLET GATE, WHEEL STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. VIEW OF UPRIGHT OUTLET GATE, WHEEL STEM AND STEM GUIDE (14' DIAMETER CIRCULAR CALCO CAST IRON SLIDE GATE), LOOKING SOUTHEAST - High Mountain Dams in Bonneville Unit, Fire Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

293

4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND WHEEL (10' HARDESTY VERTICAL LIFT GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Pot Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

294

5. VIEW OF UPRIGHT OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF UPRIGHT OUTLET GATE WHEEL, STEM AND STEM GUIDE (HARDESTY CAST IRON RECTANGULAR SLIDE GATE), LOOKING SOUTHWEST - High Mountain Dams in Bonneville Unit, Lost Lake Dam, Kamas, Summit County, UT

295

5. VIEW OF UPRIGHT OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF UPRIGHT OUTLET GATE WHEEL, STEM AND STEM GUIDE, LOOKING NORTHWEST - High Mountain Dams in Upalco Unit, Drift Lake Dam, Ashley National Forest, 11.4 miles Northwest of Swift Creek Campground, Mountain Home, Duchesne County, UT

296

5. VIEW OF UPRIGHT OUTLET GATE, STEM, STEM GUIDE AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF UPRIGHT OUTLET GATE, STEM, STEM GUIDE AND WHEEL (10' HARDESTY CAST IRON VERTICAL LIFT GATE), LOOKING WEST - High Mountain Dams in Bonneville Unit, Weir Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

297

Thousand Cankers of Black Walnut  

E-print Network

spread of TCD. Take the wood to a local landfill Take wood to an approved storage site in your city Known Locations of TCD in Colorado The Colorado State Forest Service, Colorado State University of the walnut twig beetle into areas where it does not yet occur. The beetle spreads to new locations primarily

298

Pathways to Science: STEM  

NSDL National Science Digital Library

Sponsored by NASA and the National Science Foundation, the Pathways to Science Project was created by the Institute for Broadening Participation to support "pathways to the STEM fields: science, technology, engineering, and mathematics." The project works on connecting underrepresented groups with STEM programs, funding, mentoring, and resources. The "Students" area features a sign-in area where students can sign up to receive targeted emails that will inform them of new STEM-focused scholarship and mentoring opportunities. The "Programs" area features a database of over 1500 programs designed for K-8 students, college educators, and undergraduate students. Additionally, the site also includes a "News" area where users can learn about recent success stories from universities around the United States, along with the particulars of upcoming conferences and seminars.

299

[Stem cells and cancer].  

PubMed

Surgery, radiotherapy and chemotherapy are universally recognized as the most effective anti-cancer therapies. Despite significant advances directed towards elucidating molecular mechanisms and developing clinical trials, cancer still remains a major public health issue. Cancer stem cells are a subpopulation of the cells that form the tumor. The discovery of these human cancer cells opens a perspective for understanding tumor recurrence, drug resistance and metastasis; and opens up new research directions on how cancer cells are capable of switching from dormancy to malignancy. Therapeutic alternatives emerge from a better understanding of the biology and the environment of tumor stem cells. The present paper aims to summarize the characteristics and properties of cancer stem cells, the ongoing research, as well as the best strategies for prevention and control of the mechanisms of tumor recurrence. PMID:25558756

Arvelo, Francisco; Cotte, Carlos; Sojo, Felipe

2014-12-01

300

Melanoma stem cells.  

PubMed

The cancer stem cell concept significantly broadens our understanding of melanoma biology. However, this concept should be regarded as an integral part of a holistic cancer model that also includes the genetic evolution of tumor cells and the variability of cell phenotypes within a dynamic tumor microenvironment. The biologic complexity and methodological difficulties in identifying cancer stem cells and their biomarkers are currently impeding the direct translation of experimental findings into clinical practice. Nevertheless, it is these methodological shortcomings that provide a new perspective on the phenotypic heterogeneity and plasticity of melanoma with important consequences for future therapies. The development of new combination treatment strategies, particularly with regard to overcoming treatment resistance, could significantly benefit from targeted elimination of cell subpopulations with cancer stem cell properties. PMID:25631128

Roesch, Alexander

2015-02-01

301

Role of the Alternaria alternata Blue-Light Receptor LreA (White-Collar 1) in Spore Formation and Secondary Metabolism  

PubMed Central

Alternaria alternata is a filamentous fungus that causes considerable loss of crops of economically important feed and food worldwide. It produces more than 60 different secondary metabolites, among which alternariol (AOH) and altertoxin (ATX) are the most important mycotoxins. We found that mycotoxin production and spore formation are regulated by light in opposite ways. Whereas spore formation was largely decreased under light conditions, the production of AOH was stimulated 2- to 3-fold. ATX production was even strictly dependent on light. All light effects observed could be triggered by blue light, whereas red light had only a minor effect. Inhibition of spore formation by light was reversible after 1 day of incubation in the dark. We identified orthologues of genes encoding the Neurospora crassa blue-light-perceiving white-collar proteins, a cryptochrome, a phytochrome, and an opsin-related protein in the genome of A. alternata. Deletion of the white-collar 1 (WC-1) gene (lreA) resulted in derepression of spore formation in dark and in light. ATX formation was strongly induced in the dark in the lreA mutant, suggesting a repressing function of LreA, which appears to be released in the wild type after blue-light exposure. In addition, light induction of AOH formation was partially dependent on LreA, suggesting also an activating function. A. alternata ?lreA was still able to partially respond to blue light, indicating the action of another blue-light receptor system. PMID:24532063

Pruß, Sonja; Fetzner, Ramona; Seither, Kristin; Herr, Andreas; Pfeiffer, Erika; Metzler, Manfred; Lawrence, Christopher B.

2014-01-01

302

Signal transduction in lemon seedlings in the hypersensitive response against Alternaria alternata: participation of calmodulin, G-protein and protein kinases.  

PubMed

The development of an effective hypersensitive response (HR) in any plant system relies, not only in their gene composition and expression, but also on an effective and rapid signal transduction system. Lemon seedlings induce the phenylpropanoid pathway, which results in the de novo biosynthesis of the phytoalexin scoparone, as part of the hypersensitive response against Alternaria alternata. In order to elucidate some of the signaling elements that participate in the development of HR in lemon seedlings, we used several compounds that are known as activators or inhibitors of signal transduction elements in plants or in animal cells. Lemon seedlings treated either with cholera toxin or with phorbol 12-myristate 13-acetate (PMA), in the absence of A. alternata induced phenylalanine ammonia-lyase (PAL, E. C. 4.3.1.5) and the synthesis of scoparone, suggesting the participation of a G-protein and of a serine/threonine kinase, respectively, in signal transduction. The use of trifluoperazine (TFP), W-7, staurosporine, lavendustin A or 2,5-dihydroximethyl cinnamate (DHMC) prevented PAL induction as well as scoparone biosynthesis in response to the fungal inoculation, thus allowing us to infer the participation of Calmodulin (CaM), of serine/threonine and of tyrosine protein kinases (TPK) for signal transduction in Citrus limon in response to A. alternata. PMID:12462990

Ortega, Ximena; Polanco, Rubén; Castañeda, Patricia; Perez, Luz M

2002-01-01

303

FTIR spectroscopic evaluation of changes in the cellular biochemical composition of the phytopathogenic fungus Alternaria alternata induced by extracts of some Greek medicinal and aromatic plants  

NASA Astrophysics Data System (ADS)

In this study, the biological activity of aquatic extracts of selected Greek medicinal and aromatic plants to the phytopathogenic fungus Alternaria alternata was investigated. Lamiaceae species (Hyssopus officinalis L., Melissa officinalis L., Origanum dictamnus L., Origanum vulgare L. and Salvia officinalis L.) were found to enhance significantly the mycelium growth whereas Crocus sativus appears to inhibit it slightly. M. officinalis and S. officinalis caused the highest stimulation in mycelium growth (+97%) and conidia production (+65%) respectively. In order to further investigate the bioactivity of plant extracts to A. alternata, we employed Fourier Transform Infrared Spectroscopy (FTIR). Differences of original spectra were assigned mainly to amides of proteins. The second derivative transformation of spectra revealed changes in spectral regions corresponding to absorptions of the major cellular constituents such as cell membrane and proteins. Principal component analysis of the second derivative transformed spectra confirmed that fatty acids of the cell membranes, amides of proteins and polysaccharides of the cell wall had the major contribution to data variation. FTIR band area ratios were found to correlate with fungal mycelium growth.

Skotti, Efstathia; Kountouri, Sophia; Bouchagier, Pavlos; Tsitsigiannis, Dimitrios I.; Polissiou, Moschos; Tarantilis, Petros A.

2014-06-01

304

Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit.  

PubMed

The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot. PMID:24026010

Fagundes, Cristiane; Pérez-Gago, María B; Monteiro, Alcilene R; Palou, Lluís

2013-09-16

305

FTIR spectroscopic evaluation of changes in the cellular biochemical composition of the phytopathogenic fungus Alternaria alternata induced by extracts of some Greek medicinal and aromatic plants.  

PubMed

In this study, the biological activity of aquatic extracts of selected Greek medicinal and aromatic plants to the phytopathogenic fungus Alternaria alternata was investigated. Lamiaceae species (Hyssopus officinalis L., Melissa officinalis L., Origanum dictamnus L., Origanum vulgare L. and Salvia officinalis L.) were found to enhance significantly the mycelium growth whereas Crocus sativus appears to inhibit it slightly. M. officinalis and S. officinalis caused the highest stimulation in mycelium growth (+97%) and conidia production (+65%) respectively. In order to further investigate the bioactivity of plant extracts to A. alternata, we employed Fourier Transform Infrared Spectroscopy (FTIR). Differences of original spectra were assigned mainly to amides of proteins. The second derivative transformation of spectra revealed changes in spectral regions corresponding to absorptions of the major cellular constituents such as cell membrane and proteins. Principal component analysis of the second derivative transformed spectra confirmed that fatty acids of the cell membranes, amides of proteins and polysaccharides of the cell wall had the major contribution to data variation. FTIR band area ratios were found to correlate with fungal mycelium growth. PMID:24657421

Skotti, Efstathia; Kountouri, Sophia; Bouchagier, Pavlos; Tsitsigiannis, Dimitrios I; Polissiou, Moschos; Tarantilis, Petros A

2014-06-01

306

Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.  

PubMed

Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both A. rabiei and Al. solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of A. rabiei and Al. solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity. PMID:25372118

Kim, Wonyong; Park, Chung-Min; Park, Jeong-Jin; Akamatsu, Hajime O; Peever, Tobin L; Xian, Ming; Gang, David Roger; Vandemark, George; Chen, Weidong

2014-11-01

307

Role of the Alternaria alternata blue-light receptor LreA (white-collar 1) in spore formation and secondary metabolism.  

PubMed

Alternaria alternata is a filamentous fungus that causes considerable loss of crops of economically important feed and food worldwide. It produces more than 60 different secondary metabolites, among which alternariol (AOH) and altertoxin (ATX) are the most important mycotoxins. We found that mycotoxin production and spore formation are regulated by light in opposite ways. Whereas spore formation was largely decreased under light conditions, the production of AOH was stimulated 2- to 3-fold. ATX production was even strictly dependent on light. All light effects observed could be triggered by blue light, whereas red light had only a minor effect. Inhibition of spore formation by light was reversible after 1 day of incubation in the dark. We identified orthologues of genes encoding the Neurospora crassa blue-light-perceiving white-collar proteins, a cryptochrome, a phytochrome, and an opsin-related protein in the genome of A. alternata. Deletion of the white-collar 1 (WC-1) gene (lreA) resulted in derepression of spore formation in dark and in light. ATX formation was strongly induced in the dark in the lreA mutant, suggesting a repressing function of LreA, which appears to be released in the wild type after blue-light exposure. In addition, light induction of AOH formation was partially dependent on LreA, suggesting also an activating function. A. alternata ?lreA was still able to partially respond to blue light, indicating the action of another blue-light receptor system. PMID:24532063

Pruss, Sonja; Fetzner, Ramona; Seither, Kristin; Herr, Andreas; Pfeiffer, Erika; Metzler, Manfred; Lawrence, Christopher B; Fischer, Reinhard

2014-04-01

308

Cell Stem Cell Dear Student: Stem Cell Scientists' Advice  

E-print Network

a career in stem cell research?'' ``Besides lending great worth to a scholar's life, leaving spiritual prog or restrict certain types of stem cell research raised profound questions about the field's sustainability. In academia, stem cell research has quickly become institutionalized. Research universities seized the opportu

309

Normal Stem Cells and Cancer Stem Cells: The Niche Matters  

Microsoft Academic Search

Scientists have tried for decades to understand cancer development in the context of therapeutic strategies. The realization that cancers may rely on ''cancer stem cells'' that share the self-renewal feature of normal stem cells has changed the perspective with regard to new approaches for treating the disease. In this review, we propose that one of the differences between normal stem

Linheng Li; William B. Neaves

310

Stem cells today: B1. Bone marrow stem cells  

Microsoft Academic Search

This review is the second in a series of four devoted to the analysis of recent studies on stem cells. The first considered embryo stem cells (ES). This review covers bone marrow stem cells. They are analysed initially in a historical perspective, and then in relation to foundation studies in the later 20th century before a detailed analysis is presented

RG Edwards

2004-01-01

311

STEM2Stern  

NSDL National Science Digital Library

The STEM2Stern Coordination Office works alongside all of the Naval Laboratories and Warfare Centers to offer a broad range of STEM education and outreach programs to support the next generation of scientists and engineers who will bring their talents to U.S. Naval laboratories and warfighting centers. On this site, visitors will find information about the multiple programs offered in each of the fifty states, success stories of students who have gone through these programs, and information for all those interested to get involved (students, educators, parents, and mentors).

2013-07-12

312

STEM on the radio  

NASA Astrophysics Data System (ADS)

Looking for an Internet radio station focusing on programing about science, technology, engineering, and math (STEM)? The U.S. National Science Foundation (NSF) announced on 26 September the launch of Science360 Radio, which it says is the first Internet radio stream dedicated to STEM programing. Science360 includes more than 100 radio shows and podcasts that are available on the Web as well as on iPhone and Android devices. The shows originate from a variety of sources, including NSF, other U.S. government agencies, science organizations, universities, and media outlets. For more information, see http://science360.gov/files/.

Showstack, Randy

2011-10-01

313

Stem Cells and Female Reproduction  

PubMed Central

Several recent findings in stem cell biology have resulted in new opportunities for the treatment of reproductive disease. Endometrial regeneration can be driven by bone marrow derived stem cells. This finding has potential implications for the treatment of uterine disorders. It also supports a new theory for the etiology of endometriosis. The ovaries have been shown to contain stem cells that form oocytes in adults and can be cultured in vitro to develop mature oocytes. Stem cells from the fetus have been demonstrated to lead to microchimerism in the mother and implicated in several maternal diseases. Additionally the placenta may be another source of hematopoietic stem cell. Finally endometrial derived stem cells have been demonstrated to differentiate into non-reproductive tissues. While we are just beginning to understand stem cells and many key questions remain, the potential advantages of stem cells in reproductive biology and medicine are apparent. PMID:19208782

Du, Hongling; Taylor, Hugh S.

2011-01-01

314

Laser biomodulation on stem cells  

NASA Astrophysics Data System (ADS)

Stem cells are views from the perspectives of their function, evolution, development, and cause. Counterintuitively, most stem cells may arise late in development, to act principally in tissue renewal, thus ensuring an organisms long-term survival. Surprisingly, recent reports suggest that tissue-specific adult stem cells have the potential to contribute to replenishment of multiple adult tissues. Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. The spotlight on stem cells has revealed gaps in our knowledge that must be filled if we are to take advantage of their full potential for treating devastating degenerative diseases such as Parkinsons's disease and muscular dystrophy. We need to know more about the intrinsic controls that keep stem cells as stem cells or direct them along particular differentiation pathways. Such intrinsic regulators are, in turn, sensitive to the influences of the microenvironment, or niche, where stem cells normally reside. Both intrinsic and extrinsic signals regular stem cell fate and some of these signals have now been identified. Vacek et al and Wang et al have studied the effect of low intensity laser on the haemopoietic stem cells in vitro. There experiments show there is indeed the effect of low intensity laser on the haemopoietic stem cells in vitro, and the present effect is the promotion of haemopoietic stem cells proliferation. In other words, low intensity laser irradiation can act as an extrinsic signal regulating stem cell fate. In this paper, we study how low intensity laser can be used to regulate stem cell fate from the viewpoint of collective phototransduction.

Liu, Timon C.; Duan, Rui; Li, Yan; Li, Xue-Feng; Tan, Li-Ling; Liu, Songhao

2001-08-01

315

Stem Cell Interaction with Topography  

Microsoft Academic Search

\\u000a The growth and differentiation of stem cells are regulated by biochemical and biophysical cues in the extracellular microenvironment.\\u000a Increasing evidences have shown that substrate topography, one of the biophysical properties of the microenvironment, can\\u000a affect stem cell fate, such as the maintenance of embryonic stem cells and the differentiation of adult and embryonic stem\\u000a cells. The underlying mechanism of how

Benjamin K. K. Teo; Soneela Ankam; Evelyn K. F. Yim

316

Controversies over stem cell research  

Microsoft Academic Search

Much interest and effort has focused on the therapeutic potential of stem cell technology to treat presently intractable diseases. However, this scientific promise has been accompanied by important issues, including ethical hurdles, political policies and dilemmas concerning cell-source selection (embryonic versus adult stem cells). Although the contribution of stem cells to medical research seems enormous, many countries now face complex

Gorka Orive; Rosa M. Hernández; Alicia R. Gascón; Manoli Igartua; José Luis Pedraz

2003-01-01

317

Cell Stem Cell Brief Report  

E-print Network

Cell Stem Cell Brief Report Reprogramming of T Cells from Human Peripheral Blood Yuin-Han Loh,1,2,5,9,10,* 1Stem Cell Transplantation Program, Division of Pediatric Hematology Oncology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA 2Harvard Stem Cell Institute, Cambridge, MA 02138, USA 3

Church, George M.

318

STEM--Beyond the Acronym  

ERIC Educational Resources Information Center

When most educators think of STEM education, they think of fully integrated projects seamlessly combining all four disciplines--science, technology, engineering, and mathematics. Although such transdisciplinary STEM units are ideal, writes Vasquez, they are not the only way to give students valuable STEM experiences. She gives examples of two…

Vasquez, Jo Anne

2015-01-01

319

National STEM Promoting Awareness of  

E-print Network

National STEM Awareness Program Promoting Awareness of Opportunities in Science, Technology, Engineering and Math (STEM) among Underrepresented Students Blanket Purchase Agreement (BPA) available for all.o.roberts@usace.army.mil HowdoISupportaSTEMAwarenessProgram? · Identify a school or desired STEM Awareness Program site (location

US Army Corps of Engineers

320

Hematopoietic stem cell transplantation without  

E-print Network

Hematopoietic stem cell transplantation without irradiation Claudia Waskow1,2, Vikas Madan2, Susanne Bartels2,4, Ce´line Costa2, Rosel Blasig3 & Hans-Reimer Rodewald2 Hematopoietic stem cell (HSC. These obstacles prevent in vivo analysis of histoincompatible mutant stem cells and of HSC functions in non

Cai, Long

321

Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.  

PubMed

Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f. sp. lycopersici), southern blight (Sclerotium rolfsii Sacc.), and root rot (Fusarium solani). To this end, dual culture antagonism assays were carried out on 25% Tryptic Soy Agar, King B medium, and Potato Dextrose Agar to determine the effect of the strains on mycelial growth of the pathogens. The effect of two concentrations of FeCl(3) on antagonism against Alternaria alternata f. sp. lycopersici was also tested. In addition, strains were screened for ability to produce exoenzymes and siderophores. Finally, the selected Pseudomonas strain, PCI2, was evaluated for effect on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotium rolfsii Sacc., under growth chamber conditions. All strains significantly inhibited Alternaria alternata f. sp. lycopersici, particularly in 25% TSA medium. Antagonistic effect on Sclerotium rolfsii Sacc. and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strains produced cellulase or chitinase. Growth chamber studies resulted in significant increases in plant stand as well as in root dry weight. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. PMID:21507555

Pastor, Nicolás; Carlier, Evelin; Andrés, Javier; Rosas, Susana B; Rovera, Marisa

2012-03-01

322

SMOOTH MUSCLE STEM CELLS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

323

Siemens Stem Academy  

NSDL National Science Digital Library

This website hosts resources for K-12 educators looking to access and share ideas for STEM (science, technology, engineering and mathematics) education. Monthly webinars (archived), lessons, videos, a blog, posters and other materials are available. Professional development opportunities are posted. Some resources require a free registration.

2012-01-01

324

STEM At Work  

NSDL National Science Digital Library

STEM (Science Technology Engineering & Math) at work, presented by the Florida Advanced Technological Education Center, includes a number of educational puzzles for use in the classroom. Puzzles include an energy audit exercise, measurement of air bag movement, and diesel fuel additive volatility.

2011-03-17

325

Helping STEM Take Root  

ERIC Educational Resources Information Center

STEM--the catchy shorthand for "science, technology, engineering and mathematics"--has been part of the school improvement discussion for more than a decade, as educational leaders and policy makers have underscored the importance of these areas in preparing students for an internationally competitive, 21st-century economy. But while the acronym…

Schachter, Ron

2011-01-01

326

Helping STEM Take Root  

ERIC Educational Resources Information Center

STEM--shorthand for "science, technology, engineering, and mathematics"--has been part of the school improvement discussion for more than a decade, as educational leaders and policy makers have underscored the importance of these areas in an internationally competitive, 21st-century economy. But building and implementing programs that emphasize…

Schachter, Ron

2011-01-01

327

Global STEM Navigators  

ERIC Educational Resources Information Center

In the STEM classroom, students can work in collaborative teams to build those essential skills needed for the 21st-century world. In project-based learning (PBL), teams of four to six students are often randomly selected to describe a realistic situation that may occur in today's workplace; this may be done by counting off in fours, fives,…

Dalimonte, Cathy

2013-01-01

328

STEM Sense and Nonsense  

ERIC Educational Resources Information Center

If you can believe the daily flood of mass media stories, journal articles, and white papers, the United States is facing a STEM worker crisis. Business leaders and politicians warn that the nation is falling hopelessly behind in the global economic race because our students are unprepared for and uninterested in science, technology, engineering,…

Charette, Robert N.

2015-01-01

329

Embryonic Stem Cells  

NSDL National Science Digital Library

BioEd Online is an "educational resource for educators, students, and parents" from the Baylor College of Medicine. This is an excellent place to find educational materials and current information in the field of biology. The "Hot Topics" section of this site focus on current events and issues in biology that are "receiving national attention." The controversy surrounding embryonic stem cells, and coverage it receives in news and research publications in the United States and around the world definitely warrants a closer look at this issue. This "Hot Topic" compiled by Joseph Marx, PhD, Nancy Moreno, PhD, and Deanne Erdmann, MS, contains a brief discussion of the stem cell debate, and includes references and links for further reading. Related news articles can be found as well. Be sure to check out the related slide sets for both embryonic stem cells and stem cells. These slide shows are an excellent resource to use in the classroom. Just add the slides you wish to use to your tray and then view or download your slide tray for an instant visual resource.

Erdmann, Deanne; Marx, Joseph; Moreno, Nancy

2006-07-20

330

Epithelial Cells Stem Cells  

E-print Network

Keywords Epithelial Cells Keratins Stem Cells » Prof. Thomas M. Magin Epithelia protect the body, altered cell adhesion and signal- ling. As no molecular therapy for these conditions is available, one that the co-chaperone CHIP can remove mutant aggregated keratins in a cell culture model of EBS, leading

Schüler, Axel

331

Stem cell plasticity  

Microsoft Academic Search

The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack

Uma Lakshmipathy; Catherine Verfaillie

2005-01-01

332

A Problem with STEM  

ERIC Educational Resources Information Center

Striking differences between physics and biology have important implications for interdisciplinary science, technology, engineering, and mathematics (STEM) education. The author is a physicist with interdisciplinary connections. The research group in which he works, the Center for Nonlinear Dynamics at the University of Texas at Austin, is…

Marder, Michael

2013-01-01

333

"Excellence" in STEM Education  

ERIC Educational Resources Information Center

So what does it take to achieve excellence in STEM education? That is the title of the author's presentation delivered at International Technology and Engineering Educators Association's (ITEEA's) FTEE "Spirit of Excellence" Breakfast on March 16, 2012, in Long Beach, California. In preparation for this presentation, the author went back and read…

Clark, Aaron C.

2012-01-01

334

Short stem shoulder replacement  

PubMed Central

Context: It is agreed that it is important to anatomically reproduce the proximal humeral anatomy when performing a prosthetic shoulder replacement. This can be difficult with a long stemmed prosthesis, in particular if there is little relationship of the metaphysis to the humeral shaft. The ‘short stem’ prosthesis can deal with this problem. Aims: A prospective study assessed the results of total shoulder arthroplasty using a short stem humeral prosthesis, a ceramic humeral head, and a pegged cemented polyethylene glenoid. Materials and methods: Patients with primary shoulder osteoarthritis were recruited into this prospective trial and pre-operatively had the ASES, Constant, SPADI, and DASH scores recorded. The patients were clinically reviewed at the two weeks, eight weeks, one year, and two year mark with completion of a data form. Radiological evaluation was at the eight week, one year and two year follow-up. At the one and two year follow-up the satisfaction rating, the range of passive and active motion, Constant, ASES, SPADI, DASH and pain results were recorded and analysed with SPPS 20. Results: During the study period 97 short stem, ceramic head total shoulder replacements were carried out. At the time of follow-up 12 were two years from operation and 38 one year from operation. Active elevation was overall mean 160 degrees. Constant scores were 76 at 1 year, and 86 at 2 years, ASES 88 and 93, and satisfaction 96% and 98% respectively at one and 2 year follow up. There were no problems during insertion of the humeral prosthesis, or any radiolucent lines or movement of the prosthesis on later radiographs. Conclusion: The short stem prosthesis had no complications, and on follow up radiographs good bone fixation. These fairly short term clinical results were overall good. PMID:25258497

Bell, Simon N.; Coghlan, Jennifer A.

2014-01-01

335

Gravitropism in Leafy Dicot Stems  

NASA Technical Reports Server (NTRS)

A polarizing research microscope with rotating stage and associated camera equipment were ordered, and techniques of fixation and preparation of specimens were perfected for studying possible changes in orientation of cellulose microfibrils in cell walls of gravistimulated dicot stems. Acid ethephon solutions or acid without ethephon caused elongation of stem tissues where they were applied; stems bent away from the side of application. Acid solutions applied to the bottom of horizontal stems greatly delayed bending. Research in tissue sensitivity changes during gravitropic bending of soybean hypocotyls while immersed in auxin and in castor bean stems is also reported.

Salisbury, F. B.

1985-01-01

336

Materials as stem cell regulators  

NASA Astrophysics Data System (ADS)

The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine.

Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

2014-06-01

337

Materials as stem cell regulators  

PubMed Central

The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine. PMID:24845994

Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

2014-01-01

338

Enhanced resistance to Phytophthora infestans and Alternaria solani in leaves and tubers, respectively, of potato plants with decreased activity of the plastidic ATP/ADP transporter.  

PubMed

Recently, it has been reported that tubers of transgenic potato ( Solanum tuberosum L.) plants with decreased activity of the plastidic ATP/ADP transporter (AATP1) contain less starch, despite having an increased glucose level [P. Geigenberger et al. (2001) Plant Physiol 125:1667-1678]. The metabolic alterations correlated with enhanced resistance to the bacterium Erwinia carotovora. Here it is shown that transgenic potato tubers, possessing less starch yet increased glucose levels due to the expression of a cytoplasm-localized yeast invertase, exhibit drastic susceptibility to E. carotovora. In addition, it is demonstrated that AATP1 anti-sense tubers show an increased capacity to ward off the pathogenic fungus Alternaria solani. In contrast to AATP1 anti-sense tubers, the corresponding leaf tissue does not show changes in carbohydrate accumulation. However, upon elicitor treatment, AATP1 anti-sense leaves possess an increased capacity to release H(2)O(2) and activate various defence-related genes, reactions that are associated with substantially delayed appearance of disease symptoms caused by Phytophthora infestans. Grafting experiments between AATP1 anti-sense plants and wild-type plants indicate the presence of a signal that is generated in AATP1 rootstocks and primes wild-type scions for potentiated activation of cellular defence responses in leaves. Together, the results suggest that (i) the enhanced pathogen tolerance of AATP1 anti-sense tubers is not due to "high sugar resistance", (ii) the increased disease resistance of AATP1 anti-sense tubers is effective against different types of pathogen and (iii) a systemic signal induced by antisensing the plastidic ATP/ADP transporter in potato tubers confers increased resistance to pathogens. PMID:12721851

Conrath, Uwe; Linke, Christoph; Jeblick, Wolfgang; Geigenberger, Peter; Quick, W Paul; Neuhaus, H Ekkehard

2003-05-01

339

Stem Cells and Leukaemia  

Microsoft Academic Search

Studies performed at RCRM have shown that hematopoietic and immune systems’ reconstitution after irradiation depends greatly\\u000a on the functional abilities of the stem cells. Subset analysis and expression of CD34+ antigens on bone marrow and peripheral\\u000a blood cells were studied in Chernobyl accident clean-up workers including patients with leukemia and myelodysplasia and patients\\u000a exposed to the natural levels of irradiation.

Volodymyr Bebeshko; Dimitry Bazyka

340

Melanoma Stem Cells  

Microsoft Academic Search

\\u000a The hypothesis that tumor initiation and growth are driven by a subpopulation of malignant cells, that is, cancer stem cells\\u000a (CSCs), has received considerable attention. The CSC concept predicts that the design of novel therapies that ablate CSCs\\u000a or target CSC-specific protumorigenic signaling pathways might result in more durable therapeutic responses in cancer patients\\u000a than those achieved by therapeutic approaches

Tobias Schatton; Markus H. Frank

341

Microarrays and Stem Cells  

NSDL National Science Digital Library

In this activity, learners use microarray technology to determine which genes are turned on and off at various points in the differentiation of pluripotent stem cells on their way to becoming pancreatic β cells. An introductory PowerPoint, reading, video clip and an animation provide learners with background information needed to interpret the results of a paper microarray simulation. Learners will position cDNA strips on mini-microarrays to discover which genes are expressing, to what degree they are expressing, and which are not. They use these findings to trace the differentiation of embryonic stem cells that give rise to pancreatic β cells and other cell types. The role of growth factors and proximity of other cell types is central to learners understanding how researchers may direct the ultimate fate of stem cells. The value of this in treating diabetes is also discussed. This activity is recommended for learners studying Biology at the High School (honors, IB and AP) or Undergraduate level.

Colvard, Mary

2010-01-01

342

EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Long-Term, Stable Differentiation of Human Embryonic Stem  

E-print Network

EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Long-Term, Stable Differentiation of Human Embryonic Stem Cell-Derived Neural Precursors Grafted into the Adult Mammalian Neostriatum IGOR NASONKIN Words. Cellular therapy · Embryonic stem cells · Neural differentiation · Neural induction · Neural stem

Ryugo, David K.

343

Biomaterials as Stem Cell Niche: Cardiovascular Stem Cells  

Microsoft Academic Search

\\u000a A tissue-specific stem cell niche functions to direct either self-renewal or differentiation. The niche comprises all local\\u000a cues that can be sensed by the cell including soluble and insoluble signals, physical forces and cell–cell contacts. Approximating\\u000a the stem cell niche through the utilization of biomaterials may give rise to a greater understanding of the biology of the\\u000a stem cell niche

Ge Zhang; Laura J. Suggs

344

Stem Cell Basics About this document  

E-print Network

that are the focus of scientific research, and the potential use of stem cells in research and in treating disease1 Stem Cell Basics About this document This primer on stem cells is intended for anyone who wishes to learn more about the biological properties of stem cells, the important questions about stem cells

Bandettini, Peter A.

345

Background Information 1. What are stem cells?  

E-print Network

Background Information 1. What are stem cells? 2. What might stem cell research achieve? 3. Why we need to continue research using embryonic stem cells? 4. Time taken for discoveries 5. Examples of stem cell therapies in clinical trials 6. Patentability of human embryonic stem cell therapies 7. Creation

Rambaut, Andrew

346

Stem cells in gastroenterology and hepatology  

Microsoft Academic Search

Cellular and tissue regeneration in the gastrointestinal tract and liver depends on stem cells with properties of longevity, self-renewal and multipotency. Progress in stem cell research and the identification of potential esophageal, gastric, intestinal, colonic, hepatic and pancreatic stem cells provides hope for the use of stem cells in regenerative medicine and treatments for disease. Embryonic stem cells and induced

Michael Quante; Timothy C. Wang

2009-01-01

347

Measuring stem cell circadian rhythm.  

PubMed

Circadian rhythms are biological rhythms that occur within a 24-h time cycle. Sleep is a prime example of a circadian rhythm and with it melatonin production. Stem cell systems also demonstrate circadian rhythms. This is particularly the case for the proliferating cells within the system. In fact, all proliferating cell populations exhibit their own circadian rhythm, which has important implications for disease and the treatment of disease. Stem cell chronobiology is particularly important because the treatment of cancer can be significantly affected by the time of day a drug is administered. This protocol provides a basis for measuring hematopoietic stem cell circadian rhythm for future stem cell chronotherapeutic applications. PMID:25388388

Hrushesky, William; Rich, Ivan N

2015-01-01

348

Mechanotransduction: Tuning Stem Cells Fate  

PubMed Central

It is a general concern that the success of regenerative medicine-based applications is based on the ability to recapitulate the molecular events that allow stem cells to repair the damaged tissue/organ. To this end biomaterials are designed to display properties that, in a precise and physiological-like fashion, could drive stem cell fate both in vitro and in vivo. The rationale is that stem cells are highly sensitive to forces and that they may convert mechanical stimuli into a chemical response. In this review, we describe novelties on stem cells and biomaterials interactions with more focus on the implication of the mechanical stimulation named mechanotransduction. PMID:24956164

D'Angelo, Francesco; Tiribuzi, Roberto; Armentano, Ilaria; Kenny, Josè Maria; Martino, Sabata; Orlacchio, Aldo

2011-01-01

349

Benefits Stemming from Space Exploration  

E-print Network

Benefits Stemming from Space Exploration September 2013 International Space from Space Exploration Table of Content Executive Summary .......................................................................................................................................... 3 2. Fundamental Benefits of Space Exploration

Waliser, Duane E.

350

Proposal to study stem forgings  

SciTech Connect

Reservoir designs consist of two primary features including the stem(s) and the body segment. The stem is either an integral part of the reservoir or is joined at some point in the fabrication sequence. The current interest is in high strength stems for advanced reservoir designs. The processing necessary to achieve these strength levels may result in heavily cold worked microstructures which may not interface well with the stem requirements. For instance, cold worked 316 plate stock has shown decreased hydrogen compatibility when contrasted to the annealed version in laboratory tests. More recently, Precision Forge produced a 100 ksi yield strength, 304L stem forging with a heavily deformed microstructure which also may show decreased compatibility in hydrogen. The proposed forging contract will evaluate the influence of forging parameters on the microstructure and mechanical properties of 304L and 316 stem forgings. A summary of the data available on 304L stem forgings is shown graphically. The yield strength values are shown for each set of forging parameters. Tensile tests and microstructural examination will be conducted to complete the information for 304L and create a similar graph for 316 stem forgings.

Odegard, B.C.

1982-06-25

351

Human Embryonic Stem Cell Registry  

NSDL National Science Digital Library

The National Institutes of Health (NIH) has recently released the Human Embryonic Stem Cell Registry in response to the President's announcement on August 9, 2001 to allow federal funds for stem cell research. The site lists the eleven laboratories or companies that meet the specific criteria for approved stem cell lines and explains the criteria themselves. The NIH gives the number of actual lines for each entity, the NIC and providers code for each, as well as contact information. The Website also provides links to those seeking additional information about NIH stem cell information, grants and funding opportunities, technology transfer issues, and further facts about the NIH.

2001-01-01

352

iSeek: STEM Careers  

NSDL National Science Digital Library

Minnesota's iSeek website "works with the state's workforce development and education authorities to develop and inform policy and to strategize services for career planning, education and e-learning, and workforce development." But the resources on the STEM Careers and Skills section of the site aren't just for those people living in Minnesota; this section provides all visitors the opportunity to explore STEM career skills that can be helpful no matter what state they live in. Visitors interested in learning what STEM skills are, should check out the link "Understanding STEM Skills". Here key STEM skills are outlined, such as analytical skills, science skills, technical, and math skills. The site also goes on to outline some of the soft skills that those in STEM careers should have, such as leadership, organization, communication, and creative skills. Visitors can take a free 5-10 minute "Skills Assessment" to determine which of their interests and skills match up with STEM careers. The "STEM Careers" link has a list of high-demand STEM careers, average hourly wage, and typical education requirements.

353

An Ecological Model of STEM Education: Operationalizing STEM FOR ALL  

ERIC Educational Resources Information Center

This article describes a framework for how to provide more accessible, relevant, and effective instruction in science, technology, engineering, and mathematics (STEM) education to all students. The STEM for All initiative asserts that all students, including those with disabilities and other diverse learning needs, should be included in meaningful…

Basham, James D.; Israel, Maya; Maynard, Kathie

2010-01-01

354

6. VIEW SHOWING UPRIGHT OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. VIEW SHOWING UPRIGHT OUTLET GATE WHEEL, STEM AND STEM GUIDE, WITH LOG ACCESS STRUCTURE, LOOKING WEST - High Mountain Dams in Upalco Unit, Bluebell Lake Dam, Ashley National Forest, 11.2 miles Northwest of Swift Creek Campground, Mountain Home, Duchesne County, UT

355

5. VIEW SHOWING UPRIGHT OUTLET GATE WHEEL, STEM AND STEM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW SHOWING UPRIGHT OUTLET GATE WHEEL, STEM AND STEM GUIDE, WITH LOG ACCESS STRUCTURE, LOOKING SOUTHEAST - High Mountain Dams in Upalco Unit, Bluebell Lake Dam, Ashley National Forest, 11.2 miles Northwest of Swift Creek Campground, Mountain Home, Duchesne County, UT

356

Are STEM High School Students Entering the STEM Pipeline?  

ERIC Educational Resources Information Center

This study compared the career skills and interests for students in two STEM schools to national data. Students completed the KUDER skills assessment and career planning online tools. Results were compared across school, grade level, and sex. The results provided evidence that STEM high school students expressed career intents in predominately…

Franco, M. Suzanne; Patel, Nimisha H.; Lindsey, Jill

2012-01-01

357

Learning for STEM Literacy: STEM Literacy for Learning  

ERIC Educational Resources Information Center

We are in the STEM generation whose comprehensive purpose is to resolve (1) societal needs for new technological and scientific advances; (2) economic needs for national security; and (3) personal needs to become a fulfilled, productive, knowledgeable citizen. STEM specifically refers to science, technology, engineering, and mathematics, but now…

Zollman, Alan

2012-01-01

358

Advancing the STEM Workforce through STEM-Centric Career Development  

ERIC Educational Resources Information Center

Preparing for the future is not what it used to be. Yet, advising students, preparing lessons, and promoting the value of STEM options remains constant. As a result, technical and engineering educators seek clarity about the future of careers, career development, and ways to promote STEM options. Recently, the ITEEA conference allowed the author…

Feller, Rich

2011-01-01

359

Blood and Marrow Stem Cell Transplant  

MedlinePLUS

... What Is a Blood and Marrow Stem Cell Transplant? A blood and marrow stem cell transplant replaces ... replace the missing white blood cells. Types of Transplants The two main types of stem cell transplants ...

360

Federal Policy on Stem Cell Research  

MedlinePLUS

... U.S. policy? More FAQs Links to related resources Stem Cell Research Center for Regenerative Medicine NIH Stem Cell Unit ... of Health (NIH) can support and conduct human stem cell research. The HHS Secretary, through the NIH Director, is ...

361

What's It Like to Donate Stem Cells?  

MedlinePLUS

... learn more What’s it like to donate stem cells? People usually volunteer to donate stem cells for ... autologous transplant. If you want to donate stem cells for someone else People who want to donate ...

362

FDA Warns About Stem Cell Claims  

MedlinePLUS

... Biologics Articulos en Espanol FDA Warns About Stem Cell Claims Search the Consumer Updates Section Researchers hope ... forming system. back to top Regulation of Stem Cells FDA regulates stem cells in the U.S. to ...

363

Sources of Stem Cells for Transplant  

MedlinePLUS

... Topic Donor matching for allogeneic transplant Sources of stem cells for transplant There are 3 possible sources of ... cord blood transplants are being actively studied. Which stem cell source is best? All 3 sources of stem ...

364

7 CFR 29.6039 - Stem rot.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action....

2011-01-01

365

7 CFR 29.6039 - Stem rot.  

... 2014-01-01 2014-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action....

2014-01-01

366

7 CFR 29.6039 - Stem rot.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action....

2013-01-01

367

7 CFR 29.6039 - Stem rot.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action....

2010-01-01

368

7 CFR 29.6039 - Stem rot.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture... Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action....

2012-01-01

369

STEM Colorado: Doppler Shift  

NSDL National Science Digital Library

This applet demonstrates the Doppler shift. The user can control the frequency of the sound source and the sound speed. The chart recorder at the bottom displays the wave crests as detected by the receiver and their frequency. It also displays the instantaneous wavelength if the ear is at rest. The user can drag the source or the receiver to any location in the display and choose the velocity of each. This is part of a larger collection of applets by STEM Colorado focused mostly on topics in astronomy.

Mccray, Richard; Koelemay, Andrew

2008-08-30

370

STEM Colorado: Galactic Communication  

NSDL National Science Digital Library

This applet illustrates the challenges of communicating with extraterrestrial civilizations. It shows a galaxy with a diameter of 100,000 light years. The user is able to control the average lifetime of communicating civilizations and the birth rate of such civilizations in the Milky Way galaxy. After hitting start, Earth appears and begins transmitting its signal. When Earth receives a signal from another civilization, a line appears connecting them. The applet will automatically pause when Earth ceases to communicate. Signals change color when a civilization ceases to exist. This is part of a larger collection of applets by STEM Colorado focused mostly on topics in astronomy.

Mccray, Richard; Koelemay, Andrew

2008-08-28

371

STEM Careers Exploration  

NSDL National Science Digital Library

This activity includes a presentation with links to videos about scientists and engineers working with NASA's Global Precipitation Measurement Mission (from the Faces of GPM series), as well as other STEM careers videos, followed by a number of links to online career resources. It is designed to be used by students working at their own pace, choosing which videos and links they are interested in watching and exploring, but could also be used with a larger group. As part of the activity, students identify personal skills and abilities related to career interests and develop a career goal. Includes a student capture sheet with guiding questions.

372

Stem Cell Research  

SciTech Connect

We have identified a population of primitive cells in normal human post-natal bone marrow that can, at the single cell level, differentiate in many ways and also proliferate extensively. These cells can differentiate in vitro into most mesodermal cell types (for example, bone cells, and others), as well as cells into cells of the nervous system. The finding that stem cells exist in post-natal tissues with previously unknown proliferation and differentiation potential opens up the possibility of using them to treat a host of degenerative, traumatic or congenital diseases.

Catherine Verfaillie

2009-01-23

373

STEM Colorado: Random Walk  

NSDL National Science Digital Library

This applet demonstrates random walk in two dimensions. The user can specify how many particles appear at the center of the circle and the mean free path as a fraction of the radius of the circle. The path lengths are randomized with an exponential distribution. A histogram shows the number of times each particle has been deflected before it escapes the circle. It also shows the mean number of scatterings and the standard deviation. This is part of a larger collection of applets by STEM Colorado focused mostly on topics in astronomy.

Mccray, Richard; Koelemay, Andrew

2008-11-04

374

Overexpression of the tomato Asc-1 gene mediates high insensitivity to AAL toxins and fumonisin B1 in tomato hairy roots and confers resistance to Alternaria alternata f. sp. lycopersici in Nicotiana umbratica plants.  

PubMed

The sphinganine-analog mycotoxins (SAMs) fumonisin B1 and AAL toxins are inhibitors of eukaryotic sphinganine N-acyltransferase in vitro. Treatment of eukaryotes with SAMs generally results in an accumulation of sphingoid base precursors and a depletion of complex sphingolipids. The asc,asc genotypes of tomato (Lycopersicon esculentum) and Nicotiana umbratica are sensitive to SAMs and host of the AAL toxin-producing fungus Alternaria alternata f. sp. lycopersici. Codominant insensitivity to SAMs in tomato is mediated by the Asc-1 gene, and sensitivity is associated with a frame-shift mutation present in asc-1. We investigated the function of Asc-1 in mediating insensitivity to SAMs and resistance to the fungus by overexpression of asc-1 and Asc-1. In this study, it is shown that overexpression of these genes did not lead to visual symptoms in tomato hairy roots and N. umbratica plants. Overexpression of asc-1 did not influence the (in)sensitivity to SAMs. Overexpression of Asc-1 in SAM-sensitive hairy roots and N. umbratica plants, however, mediated a high insensitivity to SAMs and resistance to plant infection by Alternaria alternata f. sp. lycopersici. PMID:11858172

Brandwagt, Bas F; Kneppers, Tarcies J A; Nijkamp, H John J; Hille, Jacques

2002-01-01

375

Adult skeletal muscle stem cells.  

PubMed

Skeletal muscles in vertebrates have a phenomenal regenerative capacity. A muscle that has been crushed can regenerate fully both structurally and functionally within a month. Remarkably, efficient regeneration continues to occur following repeated injuries. Thousands of muscle precursor cells are needed to accomplish regeneration following acute injury. The differentiated muscle cells, the multinucleated contractile myofibers, are terminally withdrawn from mitosis. The source of the regenerative precursors is the skeletal muscle stem cells-the mononucleated cells closely associated with myofibers, which are known as satellite cells. Satellite cells are mitotically quiescent or slow-cycling, committed to myogenesis, but undifferentiated. Disruption of the niche after muscle damage results in their exit from quiescence and progression towards commitment. They eventually arrest proliferation, differentiate, and fuse to damaged myofibers or make de novo myofibers. Satellite cells are one of the well-studied adult tissue-specific stem cells and have served as an excellent model for investigating adult stem cells. They have also emerged as an important standard in the field of ageing and stem cells. Several recent reviews have highlighted the importance of these cells as a model to understand stem cell biology. This chapter begins with the discovery of satellite cells as skeletal muscle stem cells and their developmental origin. We discuss transcription factors and signalling cues governing stem cell function of satellite cells and heterogeneity in the satellite cell pool. Apart from satellite cells, a number of other stem cells have been shown to make muscle and are being considered as candidate stem cells for amelioration of muscle degenerative diseases. We discuss these "offbeat" muscle stem cells and their status as adult skeletal muscle stem cells vis-a-vis satellite cells. The ageing context is highlighted in the concluding section. PMID:25344672

Sambasivan, Ramkumar; Tajbakhsh, Shahragim

2015-01-01

376

Mimicking Stem Cell Niches to Increase Stem Cell Expansion  

PubMed Central

Summary Niches regulate lineage-specific stem cell self-renewal vs. differentiation in vivo and are comprised of supportive cells and extracellular matrix components arranged in a 3-dimensional topography of controlled stiffness in the presence of oxygen and growth factor gradients. Mimicking stem cell niches in a defined manner will facilitate production of the large numbers of stem cells needed to realize the promise of regenerative medicine and gene therapy. Progress has been made in mimicking components of the niche. Immobilizing cell-associated Notch ligands increased the self-renewal of hematopoietic (blood) stem cells. Culture on a fibrous scaffold that mimics basement membrane texture increased the expansion of hematopoietic and embryonic stem cells. Finally, researchers have created intricate patterns of cell-binding domains and complex oxygen gradients. PMID:18725291

Dellatore, Shara M.; Garcia, A. Sofia; Miller, William M.

2008-01-01

377

Harvard Stem Cell Institute  

NSDL National Science Digital Library

The Harvard Stem Cell Institute (HSCI) was formed in 2004 to "draw Harvard's resources together by establishing a cooperative community of scientists and practitioners, by developing new ways to fund and support research, and by promoting opportunities for open communication and education." Their website features videos of HSCI scientists speaking about their selected disease programs. Visitors can click on a video as it appears, or they can wait for one of the next videos in the rotation. To read about the disease programs, visitors can click on the "Research" tab near the top of the page, and then select the "Research Programs" link to read about the different programs and the lead researcher. Research programs include the "Blood Disease Program", "Cancer Program", "Cardiovascular Disease Program", "Kidney Disease Program", "Nervous System Diseases Program", and the "Translational Research Program". The "Resources" tab near the top of the page has video of a great series of education sessions that are held quarterly by HSCI, and which address the medical, religious, economic, and public policy concerns that stem cell research presents. There are eight sessions to watch, and each runs longer than an hour, so each topic is covered in exquisite detail.

2009-11-09

378

Harvard Stem Cell Institute  

NSDL National Science Digital Library

The Harvard Stem Cell Institute (HSCI) was formed in 2004 to "draw Harvard's resources together by establishing a cooperative community of scientists and practitioners, by developing new ways to fund and support research, and by promoting opportunities for open communication and education." Their website features videos of HSCI scientists speaking about their selected disease programs. Visitors can click on a video as it appears, or they can wait for one of the next videos in the rotation. To read about the disease programs, visitors can click on the "Research" tab near the top of the page, and then select the "Research Programs" link to read about the different programs and the lead researcher. Research programs include the "Blood Disease Program", "Cancer Program", "Cardiovascular Disease Program", "Kidney Disease Program", "Nervous System Diseases Program", and the "Translational Research Program". The "Resources" tab near the top of the page has video of a great series of education sessions that are held quarterly by HSCI, and which address the medical, religious, economic, and public policy concerns that stem cell research presents. There are eight sessions to watch, and each runs longer than an hour, so each topic is covered in exquisite detail.

379

Excising the Root from STEM  

ERIC Educational Resources Information Center

There are a number of well-intentioned STEM initiatives, some designed to improve the recruitment and retention of science teachers. Sometimes it appears that the initiators are remote from direct contact with the "grass roots" issues that feed the "stem" on which the blossoms of young enthusiastic recruits to the science teaching profession are…

Lock, Roger

2009-01-01

380

Stem cells in the eye  

Microsoft Academic Search

In the adult organism, all tissue renewal and regeneration depends ultimately on somatic stem cells, and the eye is no exception. The importance of limbal stem cells in the maintenance of the corneal epithelium has long been recognised, and such cells are now used clinically for repair of a severely damaged cornea. The slow cycling nature of lens epithelial cells

Mike Boulton; Julie Albon

2004-01-01

381

AccessSTEM: Building Capacity  

ERIC Educational Resources Information Center

A series of activities were undertaken to understand the underrepresentation of people with disabilities in science, technology, engineering, and mathematics (STEM) careers and increase their participation in these fields. "AccessSTEM" collaborated with key stakeholders to conduct a "Capacity-Building Institute" ("CBI") in April 2009; share…

DO-IT, 2009

2009-01-01

382

Building STEM Opportunities for All  

ERIC Educational Resources Information Center

In response to a report from the President's Council of Advisors on Science and Technology, President Obama issued a challenge to the U.S. education system to create more than 1,000 new STEM-focused schools, including 200 high schools. Inclusive STEM-focused high schools--which focus their efforts on females, minorities, and students who are…

Lynch, Sharon J.; Peters-Burton, Erin; Ford, Michael

2015-01-01

383

Cell Stem Cell Clinical Progress  

E-print Network

, 2009), low cell numbers in single UCB units have limited the suitability of UCB transplan- tationCell Stem Cell Clinical Progress Rapid Expansion of Human Hematopoietic Stem Cells by Automated, Toronto, ON M5S 3E1, Canada 4Genomics Institute of the Novartis Research Foundation, 10675 John J. Hopkins

Zandstra, Peter W.

384

Engaging Students in STEM Education  

ERIC Educational Resources Information Center

With the "flattening" of the global economy in the 21st century, the teaching of Science, Technology, Engineering, and Mathematics (STEM) has taken on new importance as economic competition has become truly global. STEM education has evolved into a meta-discipline, an integrated effort that removes the traditional barriers between these…

Kennedy, T. J.; Odell, M. R. L.

2014-01-01

385

Special stem cells for bone.  

PubMed

Mesenchymal stem cells (MSCs) are multipotential in vitro, but their endogenous properties are poorly defined. In this issue of Cell Stem Cell, Park et al. (2012) report that an MSC-like, osteolineage-directed Mx1+ population generates new osteoblasts at sites of bone damage, suggesting its potential for skeletal repair and regeneration. PMID:22385649

Zaidi, Mone; Sun, Li; Blair, Harry C

2012-03-01

386

Cell Stem Cell Short Article  

E-print Network

Cell Stem Cell Short Article High Mitochondrial Priming Sensitizes hESCs to DNA of Pediatric Newborn Medicine 4Department of Medicine, Division of Genetics Brigham & Women's Hospital, BostonDivision of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA 7Harvard Stem Cell

Lahav, Galit

387

Deconstruction Geography: A STEM Approach  

ERIC Educational Resources Information Center

This article will define the engineering design process used to create an integrated curriculum at STEM Center Middle School, and it features the planning, implementation, and revision of the Deconstruction Geography unit. The Science Technology Engineering and Math (STEM) Center opened in the fall of 2009 as a way to relieve overcrowding at the…

Gehlhar, Adam M.; Duffield, Stacy K.

2015-01-01

388

STEM: Science Technology Engineering Mathematics  

ERIC Educational Resources Information Center

The generative economic power and social influence of Science, Technology, Engineering, and Mathematics (STEM) has made the production of a capable science and engineering workforce a priority among business and policy leaders. They are rightly concerned that without a robust STEM workforce, the nation will become less competitive in the global…

Carnevale, Anthony P.; Smith, Nicole; Melton, Michelle

2011-01-01

389

Mesenchymal stem cells in immunoregulation  

Microsoft Academic Search

Mesenchymal stem cells are present within the bone marrow cavity and serve as a reservoir for the continuous renewal of various mesenchymal tissues. Recent studies suggest that mesenchymal stem cells modulate immune reactions in vitro and escape from immune surveillance in vivo. We provide herein a discussion of issues including the current research progress on the in vitro interactions of

Xi Chen; Marilyn Ann Armstrong; Gang Li

2006-01-01

390

Stem cells for spine surgery.  

PubMed

In the past few years, stem cells have become the focus of research by regenerative medicine professionals and tissue engineers. Embryonic stem cells, although capable of differentiating into cell lineages of all three germ layers, are limited in their utilization due to ethical issues. In contrast, the autologous harvest and subsequent transplantation of adult stem cells from bone marrow, adipose tissue or blood have been experimentally utilized in the treatment of a wide variety of diseases ranging from myocardial infarction to Alzheimer's disease. The physiologic consequences of stem cell transplantation and its impact on functional recovery have been studied in countless animal models and select clinical trials. Unfortunately, the bench to bedside translation of this research has been slow. Nonetheless, stem cell therapy has received the attention of spinal surgeons due to its potential benefits in the treatment of neural damage, muscle trauma, disk degeneration and its potential contribution to bone fusion. PMID:25621119

Schroeder, Joshua; Kueper, Janina; Leon, Kaplan; Liebergall, Meir

2015-01-26

391

DEVELOPMENTAL BIOLOGY: Orienting Stem Cells  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Stem cells have the ability to self-renew and to differentiate into a variety of different cell types. However, it is not clear what determines the path taken by any particular stem cell. Discussing recent work with stem cells from the fruit fly testis (Yamashita et al.), Wallenfang and Matunis explain in their Perspective that, at least in the case of these stem cells, the trick is the asymmetric arrangement of the mitotic spindle during cell division. This asymmetric arrangement ensures that as the stem cell divides, one daughter cell remains in the environmental niche of the testis and continues to self-renew, whereas the other daughter cell is edged out of the niche and begins to differentiate.

Matthew R. Wallenfang (University of Pennsylvania; Department of Cell and Developmental Biology)

2003-09-12

392

Stem cells for spine surgery  

PubMed Central

In the past few years, stem cells have become the focus of research by regenerative medicine professionals and tissue engineers. Embryonic stem cells, although capable of differentiating into cell lineages of all three germ layers, are limited in their utilization due to ethical issues. In contrast, the autologous harvest and subsequent transplantation of adult stem cells from bone marrow, adipose tissue or blood have been experimentally utilized in the treatment of a wide variety of diseases ranging from myocardial infarction to Alzheimer’s disease. The physiologic consequences of stem cell transplantation and its impact on functional recovery have been studied in countless animal models and select clinical trials. Unfortunately, the bench to bedside translation of this research has been slow. Nonetheless, stem cell therapy has received the attention of spinal surgeons due to its potential benefits in the treatment of neural damage, muscle trauma, disk degeneration and its potential contribution to bone fusion. PMID:25621119

Schroeder, Joshua; Kueper, Janina; Leon, Kaplan; Liebergall, Meir

2015-01-01

393

Regulating the leukaemia stem cell.  

PubMed

Leukaemia stem cells (LSCs) are responsible for sustaining and propagating malignant disease, and, as such, are promising targets for therapy. Studies of human LSCs have served an important role in defining the major tenets of the cancer stem cell model, which centre on the frequencies of cancer stem cells, their potential hierarchical organisation and their degree of maturation. LSCs in acute myeloid leukaemia (AML) have recently been studied using mouse syngeneic models of leukaemia induced by MLL oncogenes. These studies have revealed that LSCs are more analogous to progenitor cells and employ embryonic stem cell-like genetic programmes for their maintenance, prompting a refinement of the original cancer stem cell model with important implications for design of therapies to selectively target LSCs. PMID:19959097

Cleary, Michael L

2009-12-01

394

Bioprinting for stem cell research.  

PubMed

Recently, there has been growing interest in applying bioprinting techniques to stem cell research. Several bioprinting methods have been developed utilizing acoustics, piezoelectricity, and lasers to deposit living cells onto receiving substrates. Using these technologies, spatially defined gradients of immobilized biomolecules can be engineered to direct stem cell differentiation into multiple subpopulations of different lineages. Stem cells can also be patterned in a high-throughput manner onto flexible implementation patches for tissue regeneration or onto substrates with the goal of accessing encapsulated stem cells of interest for genomic analysis. Here, we review recent achievements with bioprinting technologies in stem cell research, and identify future challenges and potential applications including tissue engineering and regenerative medicine, wound healing, and genomics. PMID:23260439

Tasoglu, Savas; Demirci, Utkan

2013-01-01

395

Bi-stem gripping apparatus  

NASA Technical Reports Server (NTRS)

This invention relates to devices which grip cylindrical structures and more particularly to a device which has three arcuate gripping members having frictional surfaces for gripping and compressing a bi-stem. The bi-stem gripping apparatus is constructed having a pair of side gripping members, and an intermediate gripping member disposed between them. Sheets of a gum stock silicone rubber with frictional gripping surfaces are bonded to the inner region of the gripping members and provide frictional engagement between the bi-stem and the apparatus. A latch secures the gripping apparatus to a bi-stem, and removable handles are attached, allowing an astronaut to pull the bi-stem from its cassette. A tethering ring on the outside of the gripping apparatus provides a convenient point to which a lanyard may be attached.

Sanders, Fred G. (inventor)

1988-01-01

396

Types of Stem Cell Transplants for Treating Cancer  

MedlinePLUS

... of stem cells for transplant Types of stem cell transplants for treating cancer In a typical stem ... from your identical twin or triplet Autologous stem cell transplants These stem cells come from you alone. ...

397

Leaving STEM: STEM Ph.D. Holders in Non-STEM Careers. Issue Brief  

ERIC Educational Resources Information Center

During the last few decades, national, state, and institutional-level initiatives have been implemented to build and expand the science, technology, engineering, and mathematics (STEM) workforce by recruiting and retaining groups of individuals that have been traditionally underrepresented in STEM in higher education. The underlying theory of…

Turk-Bicakci, Lori; Berger, Andrea

2014-01-01

398

Endodermal Stem Cell Populations Derived from Pluripotent Stem Cells  

PubMed Central

The generation of functional endodermal lineages, such as hepatocytes and pancreatic endocrine cells, from pluripotent stem cells remains a challenge. One strategy to enhance the purity, yield and maturity of endodermal derivatives is to expand endoderm committed stem or progenitor cell populations derived from pluripotent stem cells prior to final differentiation. Recent studies have shown that this is in fact a viable option both for expanding pure populations of endodermal cells as well as for generating more mature derivative tissues, as highlighted in the case of pancreatic beta cells. PMID:23452824

Cheng, Xin; Tyaboonchai, Amita; Gadue, Paul

2014-01-01

399

Allogeneic stem cell transplantation.  

PubMed

Allogeneic stem cell transplantation (HSCT) requires the harvest of an adequate number of stem cells (SC) from a histocompatible donor and their infusion into a patient following a conditioning regimen. During the past 35 years, the role of HSCT has changed from an experimental procedure for terminally ill patients to a curative treatment. In 2003, 1170 procedures were registered in Italy (Italian Group for Blood and Marrow Transplantation). The main reported indications were as follows: leukemia, lymphoproliferative diseases, myelodysplasia, and nonmalignant diseases such as thalassemia and severe aplastic anemia. Important changes have been observed in the last 5 years: the shift from bone marrow to peripheral blood as the SC source, the increasing number of alternative donors such as unrelated, partially matched family donors and cord blood SC, and the new extra-hematological indications including solid tumors. Moreover, the development of nonmyeloablative conditioning regimens have allowed physicians to perform HSCT in patients with advanced age or important comorbidities. In contrast, the availability of the Tyrosine kinase inhibitor (STI-571) for treatment of patients affected by chronic myelogenous leukemia, which was formerly the main indication for HSCT, has produced a dramatic decrease in the number of transplantations in this setting. HSCT performed in the early phases of disease and in young patients offers more than a 50% cure rate. The transplant-related mortality still represents the greatest obstacle, ranging from 20%-30%, despite the less toxic conditioning regimens, high-resolution HLA typing, and better supportive care. GvHD and infections remain the main causes of morbidity. As regards relapses, they correlate with disease status at the time of transplantation. Promising results have been recently obtained with haploidentical and with cord blood SC transplantation also in adult patients. PMID:16182779

Bosi, A; Bartolozzi, B; Guidi, S

2005-01-01

400

GPCRs in Stem Cell Function  

PubMed Central

Many tissues of the body cannot only repair themselves, but also self-renew, a property mainly due to stem cells and the various mechanisms that regulate their behavior. Stem cell biology is a relatively new field. While advances are slowly being realized, stem cells possess huge potential to ameliorate disease and counteract the aging process, causing its speculation as the next panacea. Amidst public pressure to advance rapidly to clinical trials, there is a need to understand the biology of stem cells and to support basic research programs. Without a proper comprehension of how cells and tissues are maintained during the adult life span, clinical trials are bound to fail. This review will cover the basic biology of stem cells, the various types of stem cells, their potential function, and the advantages and disadvantages to their use in medicine. We will next cover the role of G-protein coupled receptors in the regulation of stem cells and their potential in future clinical applications. PMID:23415095

DOZE, VAN A.; PEREZ, DIANNE M.

2013-01-01

401

Stem cell therapy for osteoporosis.  

PubMed

Osteoporosis is a debilitating disease that affects millions of people worldwide. Current osteoporosis treatments are predominantly bone-resorbing drugs that are associated with several side effects. The use of stem cells for tissue regeneration has raised great hope in various fields of medicine, including musculoskeletal disorders. Stem cell therapy for osteoporosis could potentially reduce the susceptibility of fractures and augment lost mineral density by either increasing the numbers or restoring the function of resident stem cells that can proliferate and differentiate into bone-forming cells. Such osteoporosis therapies can be carried out by exogenous introduction of mesenchymal stem cells (MSCs), typically procured from bone marrow, adipose, and umbilical cord blood tissues or through treatments with drugs or small molecules that recruit endogenous stem cells to osteoporotic sites. The main hurdle with cell-based osteoporosis therapy is the uncertainty of stem cell fate and biodistribution following cell transplantation. Therefore, future advancements will focus on long-term engraftment and differentiation of stem cells at desired bone sites for tangible clinical outcome. PMID:24407712

Antebi, Ben; Pelled, Gadi; Gazit, Dan

2014-03-01

402

Adult Stem and Progenitor Cells  

NASA Astrophysics Data System (ADS)

The discovery of adult stem cells in most adult tissues is the basis of a number of clinical studies that are carried out, with therapeutic use of hematopoietic stem cells as a prime example. Intense scientific debate is still ongoing as to whether adult stem cells may have a greater plasticity than previously thought. Although cells with some features of embryonic stem cells that, among others, express Oct4, Nanog and SSEA1 are isolated from fresh tissue, it is not clear if the greater differentiation potential is acquired during cell culture. Moreover, adult more pluripotent cells do not have all pluripotent characteristics typical for embryonic stem cells. Recently, some elegant studies were published in which adult cells could be completely reprogrammed to embryonic stem cell-like cells by overexpression of some key transcription factors for pluripotency (Oct4, Sox2, Klf4 and c-Myc). It will be interesting for the future to investigate the exact mechanisms underlying this reprogramming and whether similar transcription factor pathways are present and/or can be activated in adult more pluripotent stem cells.

Geraerts, Martine; Verfaillie, Catherine M.

403

Molecular Pathways: Stem Cell Quiescence  

PubMed Central

Adult stem cells are maintained in a quiescent state, but are able to exit quiescence and rapidly expand and differentiate in response to stress. The quiescent state appears to be necessary for preserving self-renewal of stem cells and a critical factor in resistance of cancer stem cells (CSC) to chemotherapy and targeted therapies. Limited knowledge of quiescence mechanisms has prevented significant advance in targeting of drug resistant quiescent CSC populations in the clinic. Thus improved understanding of the molecular mechanisms of quiescence in adult stem cells is critical for development of molecularly targeted therapies against quiescent CSC in different cancers. Recent studies have provided a better understanding of intrinsic and extrinsic regulatory mechanisms that control stem cell quiescence. It is now appreciated that the p53 gene plays a critical role in regulating stem cell quiescence. Other intrinsic regulatory mechanisms include the FoxO,, HIF-1? and NFATc1 transcription factors, and signaling through ATM and mTOR. Extrinsic microenvironmental regulatory mechanisms include Angiopoietin-1, TGF-?, BMP, TPO, N-Cadherin and integrin adhesion receptors, Wnt/?-catenin signaling and osteopontin. In this article, we review current advances in understanding normal stem cell quiescence, their significance for CSC quiescence and drug resistance, and the potential clinical applications of these findings. PMID:21593194

Li, Ling; Bhatia, Ravi

2011-01-01

404

UCLA stem cell scientists discover new airway stem cell:  

Cancer.gov

Researchers at UCLA have identified a new stem cell that participates in the repair of the large airways of the lungs, which play a vital role in protecting the body from infectious agents and toxins in the environment.

405

Planarian Regeneration and Stem Cells  

NSDL National Science Digital Library

A mini-documentary discussing the remarkable regenerative capabilities of the planarian, and how HHMI researcher Alejandro Snchez Alvarado uses them to study the biology of stem cells. This presentation is also featured on the DVD Potent Biology: Stem Cells, Cloning, and Regeneration, available for free from HHMI. This video is 11 minutes and 46 seconds in length, and available for download in Quicktime (114 MB) and Windows Media (156 MB) formats. All Stem Cell videos are located at: http://www.hhmi.org/biointeractive/stemcells/video.html.

Alejandro Sánchez Alvarado (Howard Hughes Medical Institute;)

2007-03-31

406

Embryonic Stem Cells Cell Signalling Course  

E-print Network

Embryonic Stem Cells Cell Signalling Course Ceské Budjovice November 2013 #12;Pluripotent (stem;1981 Lines of pluripotent cells were established for the first time from mouse embryo ­ Embryonic Stem Cells (Martin & Evans) Embryonic Stem Cells (ESC) ­ step from cancerous pluripotent cells of teratocarcinomas

South Bohemia, University of

407

Embryonic Stem Cells Cell Signalling Course  

E-print Network

Embryonic Stem Cells Cell Signalling Course Ceské Budjovice January 2013 #12;Pluripotent (stem;1981 Lines of pluripotent cells were established for the first time from mouse embryo ­ Embryonic Stem Cells (Martin & Evans) Embryonic Stem Cells (ESC) ­ step from cancerous pluripotent cells of teratocarcinomas

South Bohemia, University of

408

BMP signaling and stem cell regulation  

Microsoft Academic Search

Stem cells play an essential role in cellular specialization and pattern formation during embryogenesis and in tissue regeneration in adults. This is mainly due to a stem cell's ability to replenish itself (self-renewal) and, at the same time, produce differentiated progeny. Realization of these special stem cell features has changed the prospective of the field. However, regulation of stem cell

Jiwang Zhang; Linheng Li

2005-01-01

409

Stem Cell Research: Elephants in the Room  

Microsoft Academic Search

hen groups of stem cell researchers meet or when stem cell researchers publish their data and interpre- tations in scientific journals, a small cluster of important issues loom over the discussions yet often go unremarked. These issues influence much of the nature, direction, and funding of stem cell investigations, particularly those in- volving adult stem cells. The unmentionable issues are

NEIL D. THEISE

2003-01-01

410

Ferreting out stem cells from their niches  

Microsoft Academic Search

Over the past decade, it has become increasingly clear that many tissues have regenerative capabilities. The challenge has been to find the stem cells or progenitors that are responsible for tissue renewal and repair. The revolution in technological advances that permit sophisticated spatial, temporal and kinetic analyses of stem cells has allowed stem cell hunters to ferret out where stem

Valerie Horsley; Elaine Fuchs

2011-01-01

411

STEM CELL NICHE: Structure and Function  

Microsoft Academic Search

Adult tissue-specific stem cells have the capacity to self-renew and generate functional differentiated cells that replenish lost cells throughout an organism's lifetime. Studies on stem cells from di- verse systems have shown that stem cell function is controlled by extracellular cues from the niche and by intrinsic genetic programs within the stem cell. Here, we review the remarkable progress re-

Linheng Li; Ting Xie

2005-01-01

412

The Current Status of STEM Education Research  

ERIC Educational Resources Information Center

This paper explores the current Science, Technology, Engineering and Mathematics (STEM) education research base through an analysis of articles from eight journals focused on the STEM disciplines. Analyzed are both practitioner and research publications to determine the current scope of STEM education research, where current STEM education…

Brown, Josh

2012-01-01

413

The STEM Initiative: Constraints and Challenges  

ERIC Educational Resources Information Center

There is considerable national interest in STEM initiatives, but yet there is little discussion concerning what STEM means in terms of a curriculum concept to be applied to school programming. This article focuses on STEM as a curriculum concept. First, STEM programming is discussed in terms of separate subjects, correlated and broad fields…

Herschbach, Dennis R.

2011-01-01

414

Hematopoietic Stem Cell Aging: Wrinkles In Stem Cell Potential  

Microsoft Academic Search

Hematopoietic stem cells (HSC) continuously replenish the blood and immune systems. Their activity must be sustained throughout\\u000a life to support optimal immune responses. It has been thought that stem cells may be somewhat protected from age because of\\u000a their perpetual requirement to replenish the blood, however studies over the past 10 years have revealed dramatic changes\\u000a in HSC function and phenotype

S. M. Chambers; M. A. Goodell

2007-01-01

415

EMBRYONIC STEM CELLS or INDUCED PLURIPOTENT STEM CELLS? A DNA INTEGRITY PERSPECTIVE  

E-print Network

1 EMBRYONIC STEM CELLS or INDUCED PLURIPOTENT STEM CELLS? A DNA INTEGRITY PERSPECTIVE Qiang Bai Gene Therapy 2013;13(2):93-8" #12;2 ABSTRACT Induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) are two types of pluripotent stem cells that hold great promise for biomedical research

Boyer, Edmond

416

Curr Gene Ther . Author manuscript Embryonic stem cells or induced pluripotent stem cells? A DNA integrity  

E-print Network

Curr Gene Ther . Author manuscript Page /1 7 Embryonic stem cells or induced pluripotent stem cellsPSCs) and embryonic stem cells (ESCs) are two types of pluripotent stem cells that hold great promise for biomedical ; Embryonic Stem Cells ; cytology ; immunology ; Epigenesis, Genetic ; Genomic Instability ; Humans ; Induced

Paris-Sud XI, Université de

417

From stem cells to germ cells and from germ cells to stem cells  

Microsoft Academic Search

Germline and somatic stem cells are distinct types of stem cells that are dedicated to reproduction and somatic tissue regeneration, respectively. Germline stem cells (GSCs), which can self-renew and generate gametes, are unique stem cells in that they are solely dedicated to transmit genetic information from generation to generation. We developed a strategy for the establishment of germline stem cell

Gerald Wulf; Ingrid E. Ehrmann; David Elliott; Ulrich Zechner; Thomas Haaf; Andreas Meinhardt; Hans W. Michelmann; Gerlad Hasenfuss; Kaomei Guan

418

Columbia Stem Cell Initiative Tapping the potential of stem cells for human health  

E-print Network

Faculty Positions in Stem Cell Research at Columbia University Medical Center The Columbia Stem Cell of stem cells for human health. Their research covers all aspects of stem cell research, from basic Professor and Associate Professor level. Applicants' research may focus directly on stem cell biology

Adams, Mark

419

Multilocus Variable-Number-Tandem-Repeats Analysis (MLVA) distinguishes a clonal complex of Clavibacter michiganensis subsp. michiganensis strains isolated from recent outbreaks of bacterial wilt and canker in Belgium  

PubMed Central

Background Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial wilt and canker in tomato. Cmm is present nearly in all European countries. During the last three years several local outbreaks were detected in Belgium. The lack of a convenient high-resolution strain-typing method has hampered the study of the routes of transmission of Cmm and epidemiology in tomato cultivation. In this study the genetic relatedness among a worldwide collection of Cmm strains and their relatives was approached by gyrB and dnaA gene sequencing. Further, we developed and applied a multilocus variable number of tandem repeats analysis (MLVA) scheme to discriminate among Cmm strains. Results A phylogenetic analysis of gyrB and dnaA gene sequences of 56 Cmm strains demonstrated that Belgian Cmm strains from recent outbreaks of 2010–2012 form a genetically uniform group within the Cmm clade, and Cmm is phylogenetically distinct from other Clavibacter subspecies and from non-pathogenic Clavibacter-like strains. MLVA conducted with eight minisatellite loci detected 25 haplotypes within Cmm. All strains from Belgian outbreaks, isolated between 2010 and 2012, together with two French strains from 2010 seem to form one monomorphic group. Regardless of the isolation year, location or tomato cultivar, Belgian strains from recent outbreaks belonged to the same haplotype. On the contrary, strains from diverse geographical locations or isolated over longer periods of time formed mostly singletons. Conclusions We hypothesise that the introduction might have originated from one lot of seeds or contaminated tomato seedlings that was the source of the outbreak in 2010 and that these Cmm strains persisted and induced infection in 2011 and 2012. Our results demonstrate that MLVA is a promising typing technique for a local surveillance and outbreaks investigation in epidemiological studies of Cmm. PMID:23738754

2013-01-01

420

Stem cell mechanics: Auxetic nuclei  

NASA Astrophysics Data System (ADS)

The nuclei of naive mouse embryonic stem cells that are transitioning towards differentiation expand when the cells are stretched and contract when they are compressed. What drives this auxetic phenotype is, however, unclear.

Wang, Ning

2014-06-01

421

Microbioreactors for Stem Cell Research  

NASA Astrophysics Data System (ADS)

During tissue development and regeneration, stem cells respond to the entire milieu of their environment, through dynamic interactions with the surrounding cells, extracellular matrix, and cascades of molecular and physical regulatory factors. A new generation of culture systems is emerging to offer some of the biological fidelity of a whole organism within highly controllable in vitro settings and provide the cultured cells with the combinations of factors they normally encounter in vivo. There is a growing notion that such "biomimetic" systems are essential for unlocking the full potential of stem cells - for tissue regeneration as well as biological research. In this chapter, we discuss the biological principles for designing biologically inspired culture systems for stem cell research and focus on the control of stem cell microenvironment through surface patterning, microfluidics, and electrical stimulation.

Freytes, Donald O.; Vunjak-Novakovic, Gordana

422

Modeling Stem Cell Induction Processes  

E-print Network

Technology for converting human cells to pluripotent stem cell using induction processes has the potential to revolutionize regenerative medicine. However, the production of these so called iPS cells is still quite inefficient ...

Grácio, Filipe

423

Humboldt River main stem, Nevada  

USGS Publications Warehouse

This data set contains the main stem of the Humboldt River as defined by Humboldt Project personnel of the U.S. Geological Survey Nevada District, 2001. The data set was digitized on screen using digital orthophoto quadrangles from 1994.

Warmath, Eric; Medina, Rose L.

2001-01-01

424

Future Research in Adipose Stem Cell Engineering  

Microsoft Academic Search

\\u000a Adipose stem cells have a bright prospect in regenerative medicine for tissue\\/organ engineering. However, some hurdles may\\u000a hinder the progress of adipose stem cell engineering. Therefore this chapter highlights the advances in adipose stem cell\\u000a researches, and focuses on prospective researches that are needed to overcome the hurdles in adipose stem cell engineering,\\u000a i.e., to identify the various stem cells

Jeanne Adiwinata Pawitan

425

Interpreting stem diameter changes  

NASA Astrophysics Data System (ADS)

Detecting phloem transport in stem diameter changes Teemu Hölttä1, Sanna Sevanto2, Eero Nikinmaa1 1Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland 2Department of Physics, P.O. Box 48, FIN-00014 University of Helsinki, Finland Introduction The volume of living cells and xylem conduits vary according to pressures they are subjected to. Our proposition is that the behavior of the inner bark diameter variation which cannot be explained by changes in xylem water status arise from changes in the osmotic concentration of the phloem and cambial growth. Materials and methods Simultaneous xylem and stem diameter measurements were conducted between June 28th to October 4th 2006 in Southern Finland on a 47-year old, 15 meter tall, Scots pine tree (DBH 15 cm) at heights of 1.5 and 10 meters. The difference between the measured inner bark diameter and the inner bark diameter predicted from xylem diameter change with a simple model (assuming there was no change in the osmotic concentration of the phloem) is hypothesized to give the changes in the osmotic concentration of the inner bark. The simple model calculates the radial water exchange between the xylem and phloem driven by the water potential changes in the xylem. Results and Discussion The major signal in the inner bark diameter was the transpiration rate as assumed, but also a signal arising from the change in the osmotic concentration (Fig 1a). The predicted osmotic concentration of the phloem typically increased during the afternoon due to the loading of photosynthesized sugars to the phloem. Inner bark osmotic concentration followed the photosynthesis rate with a 3 and 4 hour time-lag at the top and base, respectively (Fig 1b). The connection between photosynthesis and the predicted change in phloem osmotic concentration was stronger in the upper part of the tree compared to lower part. The changes in the predicted osmotic concentration were not similar every day, indicating that photosynthesized sugars were not always immediately loaded to the phloem (not shown). Figures Fig 1. (a) Measured xylem and inner bark diameter, the inner bark diameter predicted from xylem diameter alone, and the difference between the measured inner bark diameter and the inner bark diameter predicted from xylem diameter. (b) Measured transpiration and photosynthesis rates and the change in osmotic concentration at tree top and bottom predicted by the analysis.

Hölttä, T.; Sevanto, S.; Nikinmaa, E.

2009-12-01

426

Stem-and-Leaf Plots  

NSDL National Science Digital Library

This lesson is designed to introduce students to stem-and-leaf plots as a graphical way to represent a data set. The lesson also reviews measures of central tendency. This lesson provides links to discussions and activities related to stem-and-leaf plots as well as suggested ways to integrate them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

2010-01-01

427

Stem Cells Promises to Keep?  

NSDL National Science Digital Library

Samantha and her husband Brad have two children, conceived with the help of in vitro fertilization treatments. After viewing a TV program on stem cells and their potential medical uses, Samantha is convinced that they should donate the remaining frozen embryos they have to medical research, an idea Brad strongly objects to. The case teaches about stem cells and their medical applications as well as the ethical dilemmas posed by their use.

Yaich, Lauren E.

2002-01-01

428

The stem cell debate CNN  

NSDL National Science Digital Library

As most of our readers no doubt know, President Bush made a determination on federal funding for embryonic stem cell research in August 2001, agreeing to release federal funds for research involving already existing stem cell lines. Information on this contentious topic is available at CNN's in-depth special, which features articles, analysis, video clips, and message boards devoted to the many aspects of the debate.

2001-01-01

429

Stem cells in veterinary medicine.  

PubMed

The stem cell field in veterinary medicine continues to evolve rapidly both experimentally and clinically. Stem cells are most commonly used in clinical veterinary medicine in therapeutic applications for the treatment of musculoskeletal injuries in horses and dogs. New technologies of assisted reproduction are being developed to apply the properties of spermatogonial stem cells to preserve endangered animal species. The same methods can be used to generate transgenic animals for production of pharmaceuticals or for use as biomedical models. Small and large animal species serve as valuable models for preclinical evaluation of stem cell applications in human beings and in veterinary patients in areas such as spinal cord injury and myocardial infarction. However, these applications have not been implemented in the clinical treatment of veterinary patients. Reviews on the use of animal models for stem cell research have been published recently. Therefore, in this review, animal model research will be reviewed only in the context of supporting the current clinical application of stem cells in veterinary medicine. PMID:21371354

Fortier, Lisa A; Travis, Alexander J

2011-01-01

430

Science, Technology, Engineering, and Math (STEM)  

NSDL National Science Digital Library

This report of the State Educational Technology Directors Association addresses needs in STEM eduction. The report recommends that states and school districts should develop a strategic plan to implement STEM education for all kids beginning in kindergarten, and develop specific targets for achieving these goals. As part of this strategic plan, states and school districts need to demonstrate to the community, especially parents, that STEM education is necessary for all students. States and school districts can look to broad-based initiatives developed in others states and districts for guidance. In order to provide ALL students with a solid background in STEM, the report recommends: obtaining societal support for STEM education, exposing students to STEM careers, providing on-going and sustainable STEM professional development, providing STEM pre-service teacher training and recruiting, and retaining STEM teachers.

2008-10-03

431

Engineering stem cell niches in bioreactors  

PubMed Central

Stem cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells and amniotic fluid stem cells have the potential to be expanded and differentiated into various cell types in the body. Efficient differentiation of stem cells with the desired tissue-specific function is critical for stem cell-based cell therapy, tissue engineering, drug discovery and disease modeling. Bioreactors provide a great platform to regulate the stem cell microenvironment, known as “niches”, to impact stem cell fate decision. The niche factors include the regulatory factors such as oxygen, extracellular matrix (synthetic and decellularized), paracrine/autocrine signaling and physical forces (i.e., mechanical force, electrical force and flow shear). The use of novel bioreactors with precise control and recapitulation of niche factors through modulating reactor operation parameters can enable efficient stem cell expansion and differentiation. Recently, the development of microfluidic devices and microbioreactors also provides powerful tools to manipulate the stem cell microenvironment by adjusting flow rate and cytokine gradients. In general, bioreactor engineering can be used to better modulate stem cell niches critical for stem cell expansion, differentiation and applications as novel cell-based biomedicines. This paper reviews important factors that can be more precisely controlled in bioreactors and their effects on stem cell engineering. PMID:24179601

Liu, Meimei; Liu, Ning; Zang, Ru; Li, Yan; Yang, Shang-Tian

2013-01-01

432

Stem cells, neural progenitors, and engineered stem cells.  

PubMed

Human pluripotent stem cellsHuman pluripotent stem cells (hPSCshPSCs ) have the unique potential to form every cell type in the body. This potential provides opportunities for generating humanhuman progenitorsprogenitors and other differentiated cell types for understanding human developmenthuman development and for use in cell type-specific therapiestherapies . Equally important is the ability to engineer stem cellsstem cells and their derived progenitors to mimic specific diseasedisease models. This chapter will focus on the propagationpropagation and characterization of human neural progenitorshuman neural progenitors (hNPshNPs ) derived from hPSCs with a particular focus on engineering hNPs to generate in vitroin vitro disease modelsdisease models for human neuro-mitochondrial disordersneuro-mitochondrial disorders . We will discuss the methodologies for culturing and characterizing hPSCs and hNPs; and protocols for engineering hNPs by using a novel mitochondrial transfectionmitochondrial transfection technology. PMID:25431071

Rao, Raj R; Iyer, Shilpa

2015-01-01

433

Immunotargeting of cancer stem cells  

PubMed Central

Cancer stem cells (CSCs) represent a distinctive population of tumour cells that control tumour initiation, progression, and maintenance. Their influence is great enough to risk the statement that successful therapeutic strategy must target CSCs in order to eradicate the disease. Because cancer stem cells are highly resistant to chemo- and radiotherapy, new tools to fight against cancer have to be developed. Expression of antigens such as ALDH, CD44, EpCAM, or CD133, which distinguish CSCs from normal cells, together with CSC immunogenicity and relatively low toxicity of immunotherapies, makes immune targeting of CSCs a promising approach for cancer treatment. This review will present immunotherapeutic approaches using dendritic cells, T cells, pluripotent stem cells, and monoclonal antibodies to target and eliminate CSCs. PMID:25691822

G?bka-Buszek, Agnieszka; Jankowski, Jakub; Mackiewicz, Andrzej

2015-01-01

434

Isolation and characterization of rhizosphere bacteria for the biocontrol of the damping-off disease of tomatoes in Tunisia.  

PubMed

Fluorescent Pseudomonas spp., isolated from tomato and pepper plants rhizosphere soil, was evaluated in vitro as a potential antagonist of fungal pathogens. Pseudomonas strains were tested against the causal agents of tomatoes damping-off (Sclerotinia sclerotiorum), root rot (Fusarium solani), and causal agents of stem canker and leaf blight (Alternaria alternata). For this purpose, dual culture antagonism assays were carried out on 25% tryptic soy agar, King B medium and potato dextrose agar to determine the effect of the strains on mycelial growth of the pathogens. In addition, strains were screened for their ability to produce exoenzymes and siderophores. All the strains significantly inhibited Alternaria alternata, particularly in 25% TSA medium. Antagonistic effect on Sclerotinia sclerotiorum and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strain produced cellulase or chitinase. Finally, the selected Pseudomonas strain, Psf5, was evaluated on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotinia sclerotiorum, under growth chamber conditions. In vivo studies resulted in significant increases in plant stand as well as in root dry weight. Psf5 was able to establish and survive in tomato plants rhizosphere after 40days following the planting of bacterized seeds. PMID:24296079

Hammami, Inés; Ben Hsouna, Anis; Hamdi, Naceur; Gdoura, Radhouane; Triki, Mohamed Ali

2013-01-01

435

Problematizing the STEM Pipeline Metaphor: Is the STEM Pipeline Metaphor Serving Our Students and the STEM Workforce?  

ERIC Educational Resources Information Center

Researchers and policy makers often use the metaphor of an ever-narrowing pipeline to describe the trajectory to a science, technology, engineering or mathematics (STEM) degree or career. This study interrogates the appropriateness of the STEM pipeline as the dominant frame for understanding and making policies related to STEM career trajectories.…

Cannady, Matthew A.; Greenwald, Eric; Harris, Kimberly N.

2014-01-01

436

Stem Cells for Periodontal Regeneration  

PubMed Central

Periodontal regeneration is considered to be biologically possible but clinically unpredictable. In periodontitis, inflammation manifests clinically as loss of supporting periodontal tissues and regeneration of damaged tissue is the main goal of treatment. For decades, periodontists have sought to repair the damage through a variety of surgical procedures, and use of grafting materials and growth factors, and of barrier membranes. Reports have emerged that demonstrate which populations of adult stem cells reside in the periodontal ligaments of humans and other animals. This opens the way for new cell-based therapies for periodontal regeneration. This review provides an overview of adult human stem cells and their potential use in periodontal regeneration. PMID:24265588

Pejcic, A; Kojovic, D; Mirkovic, D; Minic, I

437

Stem cells for periodontal regeneration.  

PubMed

Periodontal regeneration is considered to be biologically possible but clinically unpredictable. In periodontitis, inflammation manifests clinically as loss of supporting periodontal tissues and regeneration of damaged tissue is the main goal of treatment. For decades, periodontists have sought to repair the damage through a variety of surgical procedures, and use of grafting materials and growth factors, and of barrier membranes. Reports have emerged that demonstrate which populations of adult stem cells reside in the periodontal ligaments of humans and other animals. This opens the way for new cell-based therapies for periodontal regeneration. This review provides an overview of adult human stem cells and their potential use in periodontal regeneration. PMID:24265588

Pejcic, A; Kojovic, D; Mirkovic, D; Minic, I

2013-06-01

438

Science: Embryos and Stem Cells  

NSDL National Science Digital Library

It's quite easy to stay abreast of all the developments within the world of embryos and stem cell research with this handy site created and maintained by staff members at the Guardian newspaper. On their page, visitors can read news reports from the frontlines of scientific research in these areas, and also check out the latest posts from the weblogs they maintain on these matters. Further down the page, visitors will find a selection of specialized reports on both stem cell research and the manipulation and transformation of embryos. Visitors can also sign up to receive an RSS feed and even learn about related subjects, including genetics and biotechnology.

2008-06-04

439

MICROFLUIDIC CONTROL OF STEM CELL DIFFUSIBLE SIGNALING  

E-print Network

MICROFLUIDIC CONTROL OF STEM CELL DIFFUSIBLE SIGNALING Katarina Blagovi, Lily Y. Kim, Alison M cell differentiation. KEYWORDS: Embryonic stem cells, microfluidic perfusion, diffusible signaling; they secrete molecules to which they respond. Microfluidics offers a potential solution to this challenge

Voldman, Joel

440

Plant Structure--Leaves, Stems, and Roots  

NSDL National Science Digital Library

Page one consists of a full color illustration of an idealized plant, showing various leaf, stem and root features. Page two illustrates various adaptations of plant flowers, leaves and stems. All illustrations are accompanied by explanations of the structures' functions.

2000-01-01

441

Control of the Embryonic Stem Cell State  

E-print Network

Embryonic stem cells and induced pluripotent stem cells hold great promise for regenerative medicine. These cells can be propagated in culture in an undifferentiated state but can be induced to differentiate into specialized ...

Young, Richard A.

442

Cancer Stem Cells Found in Pancreatic Tumors  

Cancer.gov

Researchers have detected cancer stem cells in tumors from patients with pancreatic cancer. Experiments in mice suggest that these cancer stem cells may help explain the aggressive growth and spread of pancreatic tumors seen in patients.

443

7 CFR 30.4 - Stemmed.  

Code of Federal Regulations, 2013 CFR

...TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.4 Stemmed. A form of leaf tobacco consisting of a collection of leaves from which the stems or midribs have been...

2013-01-01

444

7 CFR 30.4 - Stemmed.  

Code of Federal Regulations, 2012 CFR

...TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.4 Stemmed. A form of leaf tobacco consisting of a collection of leaves from which the stems or midribs have been...

2012-01-01

445

Another call to increase STEM education  

NASA Astrophysics Data System (ADS)

As science, technology, engineering, and mathematics (STEM) education becomes increasingly important, U.S. students are lagging behind other nations on international assessments, according to a recent Trends in International Mathematics and Science study. A 22 June report from the U.S. National Research Council (NRC) calls for increasing the focus on STEM education in the United States. “To make progress in improving STEM education for all students, policy makers at the national, state, and local levels should elevate science to the same level of importance as reading and mathematics,” states the report, “Successful K-12 STEM Education: Identifying Effective Approaches in Science, Technology, Engineering, and Mathematics.” It outlines several goals: expand the number of students who pursue advanced degrees and careers in STEM fields; expand the STEM-capable workforce, while also broadening the participation of women and minorities; and increase STEM literacy for all students, whether or not they pursue STEM-related careers or additional study in those areas.

Showstack, Randy

2011-07-01

446

Stem cell differentiation: Sticky mechanical memory  

NASA Astrophysics Data System (ADS)

Physical cues from the extracellular environment influence the lineage commitment of stem cells. Now, experiments on human mesenchymal stem cells cultured on photodegradable hydrogels show that the cells' fate can also be determined by past physical environments.

Eyckmans, Jeroen; Chen, Christopher S.

2014-06-01

447

7 CFR 29.6037 - Stem.  

... Agriculture 2 2014-01-01 2014-01-01 false Stem. 29.6037 Section 29.6037 Agriculture Regulations... TOBACCO INSPECTION Standards Definitions § 29.6037 Stem. The midrib or large central vein of a tobacco...

2014-01-01

448

7 CFR 29.6037 - Stem.  

Code of Federal Regulations, 2013 CFR

... Agriculture 2 2013-01-01 2013-01-01 false Stem. 29.6037 Section 29.6037 Agriculture Regulations... TOBACCO INSPECTION Standards Definitions § 29.6037 Stem. The midrib or large central vein of a tobacco...

2013-01-01

449

7 CFR 29.6037 - Stem.  

Code of Federal Regulations, 2010 CFR

... Agriculture 2 2010-01-01 2010-01-01 false Stem. 29.6037 Section 29.6037 Agriculture Regulations... TOBACCO INSPECTION Standards Definitions § 29.6037 Stem. The midrib or large central vein of a tobacco...

2010-01-01

450

7 CFR 30.4 - Stemmed.  

Code of Federal Regulations, 2010 CFR

...Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.4 Stemmed. A form of leaf tobacco consisting of a collection of leaves from which the stems or midribs have been removed, including strip...

2010-01-01

451

7 CFR 29.6037 - Stem.  

Code of Federal Regulations, 2011 CFR

... Agriculture 2 2011-01-01 2011-01-01 false Stem. 29.6037 Section 29.6037 Agriculture Regulations... TOBACCO INSPECTION Standards Definitions § 29.6037 Stem. The midrib or large central vein of a tobacco...

2011-01-01

452

7 CFR 30.4 - Stemmed.  

...Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.4 Stemmed. A form of leaf tobacco consisting of a collection of leaves from which the stems or midribs have been removed, including strip...

2014-01-01

453

7 CFR 30.4 - Stemmed.  

Code of Federal Regulations, 2011 CFR

...Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.4 Stemmed. A form of leaf tobacco consisting of a collection of leaves from which the stems or midribs have been removed, including strip...

2011-01-01

454

7 CFR 29.6037 - Stem.  

Code of Federal Regulations, 2012 CFR

... Agriculture 2 2012-01-01 2012-01-01 false Stem. 29.6037 Section 29.6037 Agriculture Regulations... TOBACCO INSPECTION Standards Definitions § 29.6037 Stem. The midrib or large central vein of a tobacco...

2012-01-01

455

Academic Success for STEM and Non-STEM Majors  

ERIC Educational Resources Information Center

Enrollment in STEM majors has improved recently, but there continues to be concern over students' retention in those majors, especially women and minority students. The purpose of this study is to develop an integrated understanding of how multiple predictor variables affect student degree attainment, and to ascertain how those variables' impact…

Whalen, Donald F; Shelley, Mack C., II

2010-01-01

456

Making STEM Fun: How to Organize a STEM Camp  

ERIC Educational Resources Information Center

The work from the University of Central Florida's STEM summer camp (sponsored by Workforce Central Florida) is shared. The camps targeted low-SES schools with a high percentage of students on free and reduced lunch as well as high percentages of students with. Students were given preassessments and postassessments to gauge their knowledge of and…

Davis, Kimberly E. Bryant; Hardin, Stacey E.

2013-01-01

457

Spatial Organization of Embryonic Stem Cell Responsiveness to Autocrine Gp130 Ligands Reveals an Autoregulatory Stem  

E-print Network

Spatial Organization of Embryonic Stem Cell Responsiveness to Autocrine Gp130 Ligands Reveals, Ontario, Canada Key Words. Autocrine signaling · Embryonic stem cell · Niche · Self-renewal · Stem cell-location-independent processes control- ling cell fate by analyzing the spatial organization of embryonic stem cells (ESCs) using

Zandstra, Peter W.

458

Stem Cells. Author manuscript Derivation and cloning of a novel rhesus embryonic stem cell line stably  

E-print Network

Stem Cells. Author manuscript Page /1 13 Derivation and cloning of a novel rhesus embryonic stem,FR * Correspondence should be adressed to: Colette Dehay Abstract Embryonic stem cells (ESC Line ; Embryonic Stem Cells ; cytology ; enzymology ; physiology ; virology ; Genes, Reporter ; Green

Paris-Sud XI, Université de

459

Multipotent somatic stem cells contribute to the stem cell niche in the Drosophila testis  

Microsoft Academic Search

Adult stem cells reside in specialized microenvironments, or niches, that have an important role in regulating stem cell behaviour. Therefore, tight control of niche number, size and function is necessary to ensure the proper balance between stem cells and progenitor cells available for tissue homeostasis and wound repair. The stem cell niche in the Drosophila male gonad is located at

Justin Voog; Cecilia D'Alterio; D. Leanne Jones

2008-01-01

460

Cell Stem Cell CNS-Resident Glial Progenitor/Stem Cells  

E-print Network

to this rule and provides a striking example of stem/precursor cell-mediated regeneration. RemyelinationCell Stem Cell Article CNS-Resident Glial Progenitor/Stem Cells Produce Schwann Cells as well. Richardson,3,4,* and Robin J.M. Franklin1,* 1MRC Cambridge Centre for Stem Cell Biology and Regenerative

Richardson, William D.

461

Summary of current research interests Field of Research: Retinal Stem Cell Biology, Development of Stem Cell  

E-print Network

Summary of current research interests Field of Research: Retinal Stem Cell Biology, Development Müller stem cells for development of cell based therapies to treat end stage glaucoma' This research aims of Stem Cell Based Therapies to treat Retinal Diseases, Endogenous Regeneration of the human Retina Stem

Saunders, Mark

462

College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning  

ERIC Educational Resources Information Center

In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before…

Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

2010-01-01

463

hy are stem cells so valuable in research? One reason stem cells have generated  

E-print Network

W hy are stem cells so valuable in research? One reason stem cells have generated excitement in science is their versatility. Like little Swiss Army knives, stem cells provide the basic tools of stem cells -- embryonic, induced pluripotent, fetal and adult -- can all be used in different ways

464

Bio-engineering of stem/progenitor cells Blood stem cell products  

E-print Network

Bio-engineering of stem/progenitor cells Blood stem cell products: Toward sustainable benchmarks expansion of umbilical cord blood (UCB) derived hematopoietic stem and progenitor cells (HSPCs) should stem cell derived products that fulfill our current best known criteria of clinical relevance

Zandstra, Peter W.

465

Stem Cell Reports Quality Metrics for Stem Cell-Derived Cardiac Myocytes  

E-print Network

Stem Cell Reports Article Quality Metrics for Stem Cell-Derived Cardiac Myocytes Sean P. Sheehy,1, provided the original author and source are credited. SUMMARY Advances in stem cell manufacturing methods have made it possible to produce stem cell-derived cardiac myocytes at industrial scales for in vitro

466

Evaluating K-12 STEM Education Programs in Indiana: The SERI/I-STEM Partnership  

E-print Network

Evaluating K-12 STEM Education Programs in Indiana: The SERI/I-STEM Partnership Brandon Sorge1,2 , Bill Walker3 , Charlie Feldhaus1,2 1 School of Engineering and Technology 2 STEM Education Research Institute 3 I-STEM Resource Network, Purdue University Indiana University ­ Purdue University Indianapolis

Zhou, Yaoqi

467

Hematopoietic Stem Cells for Myocardial Regeneration  

Microsoft Academic Search

Adult bone marrow consists of several populations of stem cells that are the focus of investigations into their potential\\u000a to regenerate nonhematopoietic tissues. According to this hypothesis, bone marrow stem cells display a plasticity not previously\\u000a recognized. Although data supporting bone marrow stem cell plasticity is extensive, many researchers dispute this concept.\\u000a One of the most controversial aspects of stem

Donald Orlic; Richard O. Cannon III

468

Stem cells and tooth tissue engineering  

Microsoft Academic Search

The notion that teeth contain stem cells is based on the well-known repairing ability of dentin after injury. Dental stem\\u000a cells have been isolated according to their anatomical locations, colony-forming ability, expression of stem cell markers,\\u000a and regeneration of pulp\\/dentin structures in vivo. These dental-derived stem cells are currently under increasing investigation\\u000a as sources for tooth regeneration and repair. Further

Amanda H.-H. Yen; Paul T. Sharpe

2008-01-01

469

Notch signalling in cancer stem cells  

Microsoft Academic Search

A new theory about the development of solid tumours is emerging from the idea that solid tumours, like normal adult tissues,\\u000a contain stem cells (called cancer stem cells) and arise from them. Genetic mutations encoding for proteins involved in critical\\u000a signalling pathways for stem cells such as BMP, Notch, Hedgehog and Wnt would allow stem cells to undergo uncontrolled proliferation

Victoria Bolós; Moisés Blanco; Vanessa Medina; Guadalupe Aparicio; Silvia Díaz-Prado; Enrique Grande

2009-01-01

470

Stem cell aging in the Drosophila ovary  

Microsoft Academic Search

Accumulating evidence suggests that with time human stem cells may become defective or depleted, thereby contributing to aging\\u000a and aging-related diseases. Drosophila provides a convenient model system in which to study stem cell aging. The adult Drosophila ovary contains two types of stem cells: the germ-line stem cells give rise to the oocyte and its supporting nurse cells,\\u000a while the

Morris Waskar; Yishi Li; John Tower

2005-01-01

471

Stem Cell Biology and it Application to Biotechnology  

E-print Network

don't want them (causing mutations) #12;Stem Cell Research · Stem cell field is still in its infancy · Human embryonic stem cell research is a decade old, adult stem cell research has 30-year head start of this field? #12;Importance of Stem Cell Research · Stem cells allow us to study how organisms grow

Tsymbal, Evgeny Y.

472

Incorporating Ethics into K-12 STEM Education  

E-print Network

Incorporating Ethics into K-12 STEM Education: An Introduction Richard A. Burgess, M.A. Texas Tech T-STEM Center and Deputy Director, National Institute for Engineering Ethics Summer 2012 #12 for Engineering Ethics (NIEE) to incorporate Ethics into all STEM education and outreach efforts. · In this module

Gelfond, Michael

473

How Embryonic Stem Cell Lines are Made  

NSDL National Science Digital Library

Use of embryonic stem cells in research has been hotly debated for several years. This animation presents the basics on how stem cell lines are established. This animation from Cold Spring Harbor Laboratory's Dolan DNA Learning Center presents how embryonic stem cell lines are made through a series of illustrations of the processes involved.

474

Adult neurogenesis: VCAM stems the tide  

PubMed Central

Summary statement In this issue of Cell Stem Cell, Kokovay et al., uncover that VCAM1 expression in neural stem cells regulates adult neurogenesis. Cerebrospinal fluid-borne IL-1? upregulates VCAM1 expression, which in turn regulates the architecture of the stem cell niche, redox homeostasis, and neurogenesis. PMID:22862936

Lehtinen, Maria K.

2012-01-01

475

MANAGEMENT STRATEGIES FOR THE SUNFLOWER STEM WEEVIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

The sunflower stem weevil infests stalks of cultivated sunflower and can cause lodging resulting in loss of the head prior to harvest. The stem weevil also has been implicated in the transmission of Phoma black stem and charcoal rot. Field research in Kansas evaluated the effect of insecticides and ...

476

Leading Edge Stem Cell Trafficking in Tissue  

E-print Network

that achieving targeted trafficking of stem cells will be critical for effective tissue regeneration fromLeading Edge Review Stem Cell Trafficking in Tissue Development, Growth, and Disease Diana J. Laird, USA 4Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA 5

von Andrian, Ulrich H.

477

The therapeutic potential of neural stem cells  

Microsoft Academic Search

Recent evidence shows that transplantation of neural stem\\/precursor cells may protect the central nervous system from inflammatory damage through a 'bystander' mechanism that is alternative to cell replacement. This novel mechanism, which might improve the success of transplantation procedures, is exerted by undifferentiated neural stem cells, the functional characteristics of which are regulated by important stem cell regulators released by

Gianvito Martino; Stefano Pluchino

2006-01-01

478

Epigenetic regulation of aging stem cells  

Microsoft Academic Search

The function of adult tissue-specific stem cells declines with age, which may contribute to the physiological decline in tissue homeostasis and the increased risk of neoplasm during aging. Old stem cells can be ‘rejuvenated’ by environmental stimuli in some cases, raising the possibility that a subset of age-dependent stem cell changes is regulated by reversible mechanisms. Epigenetic regulators are good

E A Pollina; A Brunet

2011-01-01

479

*Institute for Stem Cell Research, GSF --National  

E-print Network

*Institute for Stem Cell Research, GSF -- National Research Center for Environment and Health neural stem cells. THE CELL BIOLOGY OF NEUROGENESIS Magdalena Götz* and Wieland B. Huttner Abstract | During the development of the mammalian central nervous system, neural stem cells and their derivative

Cai, Long

480

Advancing STEM Education: A 2020 Vision  

ERIC Educational Resources Information Center

STEM (an acronym for science, technology, engineering and mathematics) had its origins in the 1990s at the National Science Foundation (NSF) and has been used as a generic label for any event, policy, program, or practice that involves one or several of the STEM disciplines. However, a recent survey on the "perception of STEM" found that most…

Bybee, Rodger W.

2010-01-01

481

Setting FIRES to Stem Cell Research  

ERIC Educational Resources Information Center

The goal of this lesson is to present the basic scientific knowledge about stem cells, the promise of stem cell research to medicine, and the ethical considerations and arguments involved. One of the challenges of discussing stem cell research is that the field is constantly evolving and the most current information changes almost daily. Few…

Miller, Roxanne Grietz

2005-01-01

482

--Taking STem Cell SCienCe from  

E-print Network

associate professor of biomedical engineering and stem cell researcher, says that basic research the frontiers of biomedical engineering and stem cell research: associate professor Treena livingston arinzeh Medicine, dedi- cated to creating technologies to translate basic stem cell research into practical

Bieber, Michael

483

Contribution of Stem Cells to Kidney Repair  

Microsoft Academic Search

A current explanation for development of chronic renal injury is the imbalance between injurious mechanism and regenerative repair. The possibility that stem cells contribute to the repair of glomerular and tubular damage is of great interest for basic and translational research. Endogenous bone marrow-derived stem cells have been implicated in the repair of renal tissue, although the lineage of stem

Benedetta Bussolati; Peter Viktor Hauser; Raquel Carvalhosa; Giovanni Camussi

2009-01-01

484

Cell Stem Cell Alternative Induced Pluripotent  

E-print Network

-disease- relevant area of stem cell research. We agree that criteria and standards are important to allow for crossCell Stem Cell Letter Alternative Induced Pluripotent Stem Cell Characterization Criteria Cell Facility, SickKids Research Institute, University of Toronto, Toronto, Ontario M5G 1L7, Canada 2

Zandstra, Peter W.

485

Stem cells' exodus: a journey to immortality.  

PubMed

Stem cell niches provide a regulatory microenvironment that retains stem cells and promotes self-renewal. Recently in Developmental Cell, Rinkevich et al. (2013) showed that cell islands (CIs) of Botryllus schlosseri, a colonial chordate, provide niches for maintaining cycling stem cells that migrate from degenerated CIs to newly formed buds. PMID:23369706

Zhou, Yi; Lewallen, Michelle; Xie, Ting

2013-01-28

486

ADVANCE-Nebraska Advancing Women, Advancing STEM  

E-print Network

3/4/2011 1 ADVANCE-Nebraska Advancing Women, Advancing STEM Introductions Co-PIs PI Prem Paul Vice · 49% of STEM women in A&S, Engineering (11% ) · 77% of 's partners are tenure-track (66% of ' partners: Disseminationp p Proposed Program Five Barriers to Gender Equity at UNL 3. Under-recruitment of women to STEM

Farritor, Shane

487

Soft Skills, Hard Program for STEM  

E-print Network

Soft Skills, Hard Science: A Program for STEM Students with Disabilities Laura McCullough, Kathleen Deery, Michael Lawler, Debra Homa University of Wisconsin-Stout NSF Grant #RDE-1129682 May 2014 Women job placement rates for STEM students with Disabilities Monday, June 9, 14 #12;Employment gap STEM

Wu, Mingshen

488

Restoring the cornea from limbal stem cells  

PubMed Central

“…in light of the result that ABCB5 helps to amplify a PAX6-positive limbal stem cell population … it will now be important to test whether ABCB5 selection could also enhance the conversion of skin epithelial stem cells to corneal epithelial stem cells.” PMID:25562345

Frank, Markus H; Frank, Natasha Y

2015-01-01

489

Epithelial stem cells, wound healing and cancer  

Microsoft Academic Search

It is well established that tissue repair depends on stem cells and that chronic wounds predispose to tumour formation. However, the association between stem cells, wound healing and cancer is poorly understood. Lineage tracing has now shown how stem cells are mobilized to repair skin wounds and how they contribute to skin tumour development. The signalling pathways, including WNT and

Esther N. Arwert; Esther Hoste; Fiona M. Watt

2012-01-01

490

Cell Stem Cell The Systematic Production  

E-print Network

Cell Stem Cell Review The Systematic Production of Cells for Cell Therapies Daniel C. Kirouac1 10.1016/j.stem.2008.09.001 Stem cells have emerged as the starting material of choice for bioprocesses to produce cells and tissues to treat degenerative, genetic, and immunological disease

Zandstra, Peter W.

491

Patenting Human Genes and Stem Cells  

Microsoft Academic Search

Cell lines and genetically modified single cell organisms have been considered patentable subjects for the last two decades. However, despite the technical patentability of genes and stem cell lines, social and legal controversy concerning their 'ownership' has surrounded stem cell research in recent years. Some granted patents on stem cells with extremely broad claims are casting a shadow over the

Enca Martin-Rendon; Derek J. Blake

2007-01-01

492

Cardiomyocytes from Human Embryonic Stem Cells  

Microsoft Academic Search

Terminal heart failure is characterized by a significant loss of cardiac myocytes. Stem cells represent a possibility for replacing these lostmyocytes but the question of which stem cells are most ideally suited for cell transplantation therapies is still being addressed. Here, we consider human embryonic stem cells (HESC), derived from human embryos in this context. We review the methods used

R. Passier; C. Denning; C. Mummery

493

Substrate Modulus Directs Neural Stem Cell Behavior  

Microsoft Academic Search

Although biochemical signals that modulate stem cell self-renewal and differentiation were extensively studied, only recently were the mechanical properties of a stem cell's microenvironment shown to regulate its behavior. It would be desirable to have independent control over biochemical and mechanical cues, to analyze their relative and combined effects on stem-cell function. We developed a synthetic, interfacial hydrogel culture system,

Krishanu Saha; Albert J. Keung; Elizabeth F. Irwin; Yang Li; Lauren Little; David V. Schaffer; Kevin E. Healy

2008-01-01

494

Analysis of neuronal differentiation from stem cells  

Microsoft Academic Search

High-content analysis (HCA) based on automated image acquisition, image processing and analysis, and bioinformatics has a power to enhance discovery research using stem cells. Human embryonic stem cells (hESCs) are difficult to study because of the specialized conditions that affect growth rate, death and differentiation. HCA with optimized cell culture conditions provides a valuable tool for stem cell research. HCA

Michael Anhalt; Douglas E. Hughes; Suk J. Hong

2000-01-01

495

Developing Effective STEM Professional Development Programs  

ERIC Educational Resources Information Center

To help the United States stay globally competitive in terms of innovation and invention, the teaching of science, technology, engineering, and mathematics (STEM) has become a priority in P-12 education today. As the need for students to become stronger in STEM grows, so does the need for well-qualified STEM teachers who understand what is needed…

Avery, Zanj K.; Reeve, Edward M.

2013-01-01

496

Cell Stem Cell The Transcriptional Landscape  

E-print Network

Cell Stem Cell Resource The Transcriptional Landscape of Hematopoietic Stem Cell Ontogeny Shannon Stem Cell Institute, Boston, MA 02115, USA 2Department of Hematology, St. Jude Children's Research Cell Transplantation Program and Children's Hospital Boston, Boston, MA 02115, USA 9Dana Farber Cancer

Collins, James J.

497

The Top STEM Degree Producers  

ERIC Educational Resources Information Center

This article presents a list of the top Science, Technology, Engineering, and Mathematics (STEM) degree producers in the U.S. This list is broken down into seven categories: (1) Total Minority Research/Scholarship and Other Doctoral: Mathematics and Statistics; (2) Total Minority Bachelors: Biological and Biomedical Sciences; (3) Total Minority…

Diverse: Issues in Higher Education, 2012

2012-01-01

498

Stem cells in tissue engineering  

Microsoft Academic Search

The concept of producing 'spare parts' of the body for replacement of damaged or lost organs lies at the core of the varied biotechnological practices referred to generally as tissue engineering. Use of postnatal stem cells has the potential to significantly alter the perspective of tissue engineering. Successful long-term restoration of continuously self-renewing tissues such as skin, for example, depends

Paolo Bianco; Pamela Gehron Robey

2001-01-01

499