bluuebunny/crossref_metadata_2025_split huggingface dataset:
SBA‐15 pore‐width decrease via a one‐ or a two‐step covalent bonding of a Fischer tungsten carbene as measured by N2 sorption
Authors: Ojeda M. Luisa , Velásquez Celso , Campero Antonio , López‐Cortés José G. , Álvarez Cecilio , Esparza J. Marcos , Rojas Fernando 
Published: May 2008

AbstractThe chemical attachment of Fischer tungsten carbene molecules around the cylindrical walls of SBA‐15 causes a pore‐width diminution with respect to the diameters of the voids existing in the pristine substrate. The attachment is made via a bridging unit of aminopropyltriethoxysilane (APTES) that, at its ethoxysilane end, anchors on the SBA‐15 surface while, at its amino end, reacts with the tungsten carbene. The attachment can either be made in a single stage by adding the whole molecule, i.e. bridging + carbene units, or stepwise, i.e. the bridging unit is firstly attached to the silica surface and afterward the carbene group is linked to the amine end of the previous species. A remarkable result is that a uniform pore‐width decrease of 0.30 nm is achieved when the ethoxysilane bridging units are anchored on the SiO2 surface; this decrease being independent of the pore size. An additional decrease of 0.37 nm is observed when the tungsten carbene is fixed to the amine end of the bridging molecule; the total pore‐width decrease is thus 0.67 nm. In turn, the one‐stage insertion of the whole carbene molecules causes a uniform pore‐width decrease of 0.78 nm. The central cores of the functionalized pore entities remain free for the molecular transport of species that are taking place in catalytic, separation, and controlled release processes. The chemical anchoring of molecules on the surface of SBA‐15 pores can be tailor sized and occlude the existing micropores, thus representing important and fundamental industrial applications. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and Performance Properties of Cationic Fabric Softeners Derived from Different Fatty Acids and 1(2‐Hydroxyethylpiperazine)
Authors: Mishra Shilpi , Tyagi V. K. 
Published: May 2008

AbstractQuaternary ammonium salts (otherwise known as “quats”) commonly form the foundation of formulations in the antimicrobial industry. Many studies have been conducted on the biological activity of surfactants derived from fatty acids viz. lauric acid, myristic acid, stearic acid and palmitic acid and palm fatty acid with polyamine, i.e. 1(2‐hydroxyethylpiperazine). The present paper investigates the synthesis and surface‐active properties of esteramide quats derived from the esterification of the above‐mentioned fatty acids and 1(2‐hydroxyethylpiperazine) followed by quaternization using dimethyl sulphate (DMS). These derivatives were fully characterized by using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, and 13C‐NMR spectroscopy. In addition to the cationic content, surface tension, CMC (critical micelle concentration), fabric softening, rewettability, emulsification and dispersing power were determined as their surface‐active properties.
A correlative light and electron microscopic study of postnatal myelination in the murine corpus callosum
Authors: Vincze András , Mázló Mária , Seress László , Komoly Sámuel , Ábrahám Hajnalka 
Published: May 2008

AbstractOligodendroglial cells differ in their ultrastructural appearance depending on their myelin producing and maintaining activity. To better understand the relationship between light and electron microscopic features of myelination, myelin formation in the corpus callosum was studied in young postnatal mice. Immunostaining for myelin basic protein (MBP), which has an important role in myelin compaction, was compared with conventional Luxol Fast Blue myelin staining and with electron microscopic images of unlabeled tissue.MBP‐immunostaining labeled a few oligodendroglial cells at postnatal day (P)3, and a few axons at P7 in the corpus callosum, below the fronto‐parietal somatosensory cortex. By P10 there were more myelinated axons below the somatosensory cortex and the first MBP‐immunoreaction appeared in the cingulum: labeling appeared even later in the remaining areas of corpus callosum. Electron microscopy revealed numerous medium oligodendroglial cells at P7 in the corpus callosum, below the somatosensory cortex with the first sign of myelination at P10. By P14, there were numerous myelin sheaths with loosely built structure, and the number of myelin sheaths increased continuously thereafter. However, even as late as P28, the presence of both thick, compact and thin, loosely structured myelin sheaths in the same section suggested ongoing myelination. With Luxol Fast Blue myelin staining was first observed in the corpus callosum relatively late, at P14.Areal differences in myelination of the corpus callosum, seen with MBP‐immunohistochemistry, indicate that myelin formation follows cortical maturation rather than the rostro‐caudal developmental growth of the corpus callosum. Myelination of the afferent and efferent fibers within the cortical areas seems to follow the inside‐out maturational pattern of cortical neurons, with the first myelinated axons always appearing in layers V–VI.In addition to the known neuronal and astroglial factors that regulate myelin formation by oligodendroglial cells, we suggest that these cells and their myelin covering may also influence axonal maturation. Light microscopic data obtained with MBP‐immunohistochemistry correlates well with electron microscopic observations but not with Luxol Fast Blue staining which reveals myelinated axons only relatively late in development. Therefore, both MBP‐immunostaining and electron microscopy are useful, alone or in combination, for the detection of myelination, demyelination as well as remyelination processes in animal models and also in humans.
Complete orbits for twist maps on the plane
Authors: KUNZE MARKUS , ORTEGA RAFAEL 
Published: May 2008

AbstractTwist maps (θ1,r1)=f(θ,r) are considered in this paper, with no assumption on the periodicity of the map in θ. Under appropriate assumptions, the existence of infinitely many bounded (in r) complete orbits is proven. In particular, our results apply to the class of maps where λ>0 and no arithmetic condition has to be imposed on ω1/ω2.
Hydrologic response to extreme warm and cold summers in the McMurdo Dry Valleys, East Antarctica
Authors: Doran Peter T. , McKay Christopher P. , Fountain Andrew G. , Nylen Thomas , McKnight Diane M. , Jaros Chris , Barrett John E. 
Published: May 2008

AbstractThe meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present.
Comparing fixed-point and probabilistic sampling designs for monitoring the marine ecosystem near McMurdo Station, Ross Sea, Antarctica
Authors: Morehead Sally , Montagna Paul , Kennicutt Mahlon C. 
Published: May 2008

AbstractFixed-point and probabilistic sampling designs were compared to investigate which design best detected known contamination gradients in the marine ecosystem adjacent to McMurdo Station, Antarctica. The fixed-point sampling design included transects along historical contamination and physical disturbance gradients. The probabilistic sampling design used randomly selected hexagons spaced at 50 m intervals. In both designs, 15 stations were sampled over a small area (~1 km2) that extended from Winter Quarters Bay to Cape Armitage. Sediment quality triad components (sediment chemical contaminants, sediment toxicity, and a benthic index of biotic integrity) were measured to indicate chemical, toxicological, and biological effects. There were higher correlations between sediment quality triad components for the fixed-point sampling design than for the probabilistic design. The fixed-point design was better at detecting the intensity of alteration because disturbance of the marine ecosystem at McMurdo Station is localized within a small area. Based on these results, a limited fixed-point design with nine stations detected no significant change in macrofaunal community structure over a four year period from 2000–2004. However, the macrofaunal assemblages present in the contaminated portions of Winter Quarters Bay are indicative of a disturbed benthic community that has been subject to organic enrichment and toxic chemical exposure.
Opinion: Projecting the effects of environmental change on Antarctic seals
Authors: Siniff Donald B. , Garrott Robert A. , Rotella Jay J. , Fraser William R. , Ainley David G. 
Published: May 2008

AbstractWe consider how Antarctic seals may respond to changes in climate, realizing that anthropogenic alteration of food webs will influence these responses. The species considered include the ice-obligate - crabeater (Lobodon carcinophaga), Weddell (Leptonychotes weddellii), Ross (Ommataphoca rossii) and leopard (Hydrurga leptonyx) seal - and the ice-tolerant Antarctic fur seal (Arctocephalus gazella) and southern elephant seal (Mirounga leonina). The data analysed are from long-term censuses of Weddell seals in McMurdo Sound (1997–2006), and of Weddell, fur and elephant seals at Arthur Harbour, Antarctic Peninsula (1974–2005). After considering their responses to recent changes in environmental features, as well as projected and current changes to their habitat our conclusions are that the distribution and abundance of 1) crabeater and Weddell seals will be negatively affected by changes in the extent, persistence and type of annual sea ice, 2) Ross and leopard seal will be the least negatively influenced by changes in pack ice characteristics, although, as may be the case for crabeater and Weddell, population size and distribution may be altered through changes in food web dynamics, and 3) southern elephant and fur seals will respond in ways opposite to the pack ice species, but could also be influenced most immediately by changes in their food resources due to factors other than climate.
Improvement of detection of hypoattenuation in acute ischemic stroke in unenhanced computed tomography using an adaptive smoothing filter
Authors: Takahashi N. , Lee Y. , Tsai D.-Y. , Ishii K. , Kinoshita T. , Tamura H. , Kimura M. 
Published: May 2008

Background: Much attention has been directed toward identifying early signs of cerebral ischemia on computed tomography (CT) images. Hypoattenuation of ischemic brain parenchyma has been found to be the most frequent early sign. Purpose: To evaluate the effect of a previously proposed adaptive smoothing filter for improving detection of parenchymal hypoattenuation of acute ischemic stroke on unenhanced CT images. Material and Methods: Twenty-six patients with parenchymal hypoattenuation and 49 control subjects without hypoattenuation were retrospectively selected in this study. The adaptive partial median filter (APMF) designed for improving detectability of hypoattenuation areas on unenhanced CT images was applied. Seven radiologists, including four certified radiologists and three radiology residents, indicated their confidence level regarding the presence (or absence) of hypoattenuation on CT images, first without and then with the APMF processed images. Their performances without and with the APMF processed images were evaluated by receiver operating characteristic (ROC) analysis. Results: The mean areas under the ROC curves (AUC) for all observers increased from 0.875 to 0.929 ( P=0.002) when the radiologists observed with the APMF processed images. The mean sensitivity in the detection of hypoattenuation significantly improved, from 69% (126 of 182 observations) to 89% (151 of 182 observations), when employing the APMF ( P=0.012). The specificity, however, was unaffected by the APMF ( P=0.41). Conclusion: The APMF has the potential to improve the detection of parenchymal hypoattenuation of acute ischemic stroke on unenhanced CT images.
First Report of Powdery Mildew Caused by Golovinomyces cichoracearum on Orange Coneflower (Rudbeckia fulgida) in Italy
Authors: Garibaldi A. , Bertetti D. , Frati S. , Gullino M. L. 
Published: May 2008

Rudbeckia fulgida (orange coneflower), a flowering plant belonging to the Asteraceae, is increasingly used as a border in parks and gardens. In September 2007, severe outbreaks of a previously unknown powdery mildew were observed on plants in a public park in Torino (northern Italy). More than 90% of the plants were affected by the disease. Both surfaces of leaves of affected plants were covered with white mycelia and conidia. As the disease progressed, infected leaves turned yellow and wilted. Mycelia and conidia also were observed on stems and flower calyxes. Conidia were hyaline, ellipsoid, borne in chains (as many as three to four conidia per chain) and measured 34 × 23 (30 to 39 × 21 to 25) μm. Conidiophores measured 129 × 12 (89 to 181 × 11 to 13) μm and showed a foot cell measuring 88 × 12 (48 to 129 × 11 to 13) μm followed by two shorter cells. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLASTn analysis (1) of the 619 bp showed a 100% homology with the sequence of Golovinomyces cichoracearum (3). The nucleotide sequence has been assigned GenBank Accession No. EU 233820. Pathogenicity was confirmed through inoculations by gently pressing diseased leaves onto leaves of healthy R. fulgida plants. Twenty plants were inoculated. Fifteen noninoculated plants served as the control. Plants were maintained in a greenhouse at temperatures ranging from 18 to 22°C. Eight days after inoculation, typical symptoms of powdery mildew developed on inoculated plants. The fungus observed on inoculated plants was morphologically identical to that originally observed. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. To our knowledge, this is the first report of powdery mildew on R. fulgida in Italy. Powdery mildew on Rudbeckia spp. was previously reported in the United States (4), Poland, and more recently, India and Switzerland. Particularly, in Switzerland the disease has been observed on R. laciniata and R. nitida (2). The economic importance of this disease is currently limited. Voucher specimens are available at the AGROINNOVA Collection, University of Torino. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) A. Bolay. Cryptogam. Helv. 20:1, 2005. (3) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (4) D. F. Farr et al. Page 82 in: Fungi on Plants and Plants Products in the United States. The American Phytopathological Society, St Paul, MN, 1989.
First Report of Soybean Rust Caused by Phakopsora pachyrhizi in Iowa and its Statewide Occurrence
Authors: Li X. , Engelbrecht C. J. , Mueller D. S. , Yang X. B. 
Published: May 2008

On 25 September 2007, soybean leaves with lesions typical of soybean rust were found in two commercial fields located in Dallas County, Iowa. Growth stage of the infected soybean plants was near physiological maturity. Diagnosis of Phakopsora pachyrhizi on leaves was confirmed by morphological observation of uredinia and urediniospores and conventional PCR conducted by the Iowa State University Plant and Insect Diagnostic Clinic using P. pachyrhizi-specific primers Ppm1 and Ppa2 as described (1). Water blanks were used as negative controls in PCR testing. Leaves were collected from additional counties throughout Iowa and examined microscopically. Soybean rust was identified on leaves from 14 counties, almost all the counties sampled, ranging from far western to far eastern Iowa. The northernmost detection was at 42.9°N in Hancock County, which also is the northernmost detection of soybean rust in the continental United States so far. In a commercial field in Fremont County, in the southwestern corner of Iowa along the Missouri River, disease incidence was approximately 20% and disease severity was 5%. Observed disease incidence was 1 to 2% and severity was less than 1% from all other samples. Most uredinia were scattered on the leaves as single pustules or clustered in groups of three to five pustules. Pustules on some leaf samples were sporulating, depending on weather conditions at the time when samples were collected. Fresh urediniospores collected from the leaf samples were placed on glass slides with free water on the surface and incubated in a dew chamber under darkness for 8 h to test for germination. Germination rates ranged from 80 to 90%. Rust spores also were used to inoculate detached soybean trifoliate leaves, which were kept in a dew chamber under darkness for 12 h with water-soaked cotton wrapped around the petioles. Typical soybean rust pustules developed within 10 to 14 days after incubation. The detections of soybean rust in Iowa were consistent with the predictions of an aerobiological spore dispersal model, which predicted spore showers in central to western Iowa in August. Above normal wet weather in the Great Plains and Iowa may have favored the statewide disease occurrence. To our knowledge, this is the first report of soybean rust in Iowa. Reference: (1) R. D. Frederick et al. Phytopathology 92:217, 2002.
Occurrence of Four Citrus Viroids in Chongqing, China
Authors: Wang X. F. , Zhou C. Y. , Tang K. Z. , Li Z. A. 
Published: May 2008

Chongqing Municipality, located in the superior citrus belt of the upper-middle Yangtze River, is one of the most important citrus-producing areas in China. A survey was performed to evaluate the occurrence and distribution of citrus viroids in this area, where Poncirus trifoliata is the main rootstock. From 2002 to 2006, 72 samples of sweet oranges (Citrus sinensis), lemons (C. jambhiri), mandarins (C. reticulata), and mandarin hybrids, which showed stunting, bark scaling, and cracking symptoms on the rootstock, were collected and graft inoculated into Arizona 861-S1 Etrog citron (C. medica) on rough lemon rootstock and maintained in a greenhouse at 28 to 32°C. Fifty-one of the seventy-two samples were cultivars imported from abroad, and the remaining samples were all local cultivars. Sixty samples induced symptoms typical of citrus viroids on the Etrog indicator plants. To identify the causal agent(s), a one-step reverse transcription (RT)-PCR protocol, using five primer pairs (1) targeting the complete genome sequences, was used to detect Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Hop stunt viroid (HSVd), Citrus viroid III (CVd-III), and Citrus viroid IV (CVd-IV) (2). All 72 samples were infected by citrus viroids. Sixty-five and thirty-five of the seventy-two samples were positive for HSVd and CVd-III, respectively. CEVd and CBLVd were found, respectively, in 20 and 11 of 72 samples, whereas CVd-IV was not detected. Of 72 samples, 12 without typical symptoms on Etrog citrons were infected by HSVd and CBLVd. Nearly all (70 of 72) infected citrus plants harbored more than one viroid species, and two plants were both infected by CEVd, CBLVd, HSVd, and CVd-III. RT-PCR products were purified and ligated into pGEM T-Easy Vector (Promega, Madison, WI) and three clones for each of the four viroid species were sequenced and deposited in GenBank: CEVd (Accession Nos. EU382202, U382203, and EU382204); CBLVd (Accession Nos. EU382211, EU382212, and EU382213); HSVd (Accession Nos. EU382208, EU382209, and EU382210); and CVd-III (Accession Nos. EU382205, EU382206, and EU382207). BLAST analysis showed that these nucleotide sequences had greater than 94% nucleotide identity to the most similar genome sequences in GenBank. Sweet orange was more frequently infected by viroids than the other citrus cultivars. To our knowledge, this is the first report of CBLVd, HSVd, and CVd-III in Chongqing and the first report of CBLVd in China. The high incidence of citrus viroids in Chongqing necessitates rapid development of a system of propagation and testing to reduce the incidence of viroids and the associated loss of citrus production. References: (1) L. Bernard and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (2) K. Z. Tang et al. Acta Hortic. Sin. 32:408, 2005.
First Report of Sclerotinia sclerotiorum on African Daisy (Osteospermum sp.) in Italy
Authors: Garibaldi A. , Pensa P. , Minuto A. , Gullino M. L. 
Published: May 2008

African daisy (Osteospermum sp.) is an ornamental plant grown in the winter as a potted plant in Liguria (northern Italy) and is generally marketed in early-to-late spring in Italy and central and northern Europe. In the winter of 2006, stem lesions, general chlorosis, wilt, and plant death occurred in a greenhouse nursery. Affected plants were characterized by the presence of soft, watery tissues. Necrotic tissues were covered with a white, cottony mycelium. During periods of high humidity, black sclerotia differentiated within the mycelium. To recover the pathogen, diseased stem tissue was surface sterilized for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/l of streptomycin sulfate. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently isolated from affected tissue. Sclerotia produced on PDA measured 1.3 to 3.1 × 1.5 to 3.5 mm in diameter. The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and then sequenced. BLASTn analysis (1) of the 633 bp showed a 100% identity with S. sclerotiorum. The nucleotide sequence was assigned GenBank Accession No. EU 556701. Pathogenicity of two isolates obtained from infected plants was confirmed by inoculating 10 80-day-old plants grown in 14-cm-diameter pots. Inoculum consisted of 1 cm2 of mycelium excised from a 10-day-old PDA culture of each isolate and placed on the soil surface around the base of each plant. Ten plants were inoculated with each isolate and 10 noninoculated plants served as controls. Plants were maintained in a greenhouse under shade at temperatures of 10 to 22°C (average 19°C), in high relative humidity (>90%), and were watered as needed. The trial was conducted twice. All inoculated plants developed leaf yellowing within 12 days of inoculation. White, cottony mycelium and black sclerotia developed on stems and at the base of all inoculated plants, which eventually wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from the stems of inoculated plants. This disease has been reported on an Osteospermum sp. in the United States (3) and Argentina (4). To our knowledge, this is the first report of white mold on an Osteospermum sp. in Italy as well as in Europe. Currently, the economic importance of this disease is limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift. 75, 1949. (3) H. S. Gill. Plant Dis. Rep. 59:82, 1975. (4) E. R. Wright et al. Plant Dis. 89:1014, 2005.