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Low Amounts (low + amount)
Kinds of Low Amounts Selected AbstractsHighly Efficient Biomimetic Oxidation of Sulfide to Sulfone by Hydrogen Peroxide in the Presence of Manganese meso -TetraphenylporphyrinCHINESE JOURNAL OF CHEMISTRY, Issue 6 2008Xian-Tai ZHOU Abstract Low amount of manganese meso -tetraphenyl porphyrin [Mn(TPP)] was used for highly efficient selective oxidation of sulfide to sulfone by hydrogen peroxide at room temperature. Sulfones were produced directly with yields generally around 90% while the catalyst concentration was only 4×10,5 mol·L,1. In a large-scale experiment of thioanisole oxidation, the isolated yield of sulfone (87%) was obtained and the turnover number (TON) reached up to 8×106, which is the highest TON for the oxidation systems of sulfide to sulfone catalyzed by metalloporphyrins. [source] Identification and quantification of galloyl derivatives, flavonoid glycosides and anthocyanins in leaves of Pistacia lentiscus L.PHYTOCHEMICAL ANALYSIS, Issue 2 2002A. Romani Abstract Separation, identification and quantification of polyphenols was carried out on leaves of Pistacia lentiscus L., an evergreen member of the family Anacardiaceae, using semi-preparative HPLC, HPLC-photodiode array detection and HPLC-MS analysis, together with 1H- and 13C NMR. Three major classes of secondary metabolites were detected: (i) gallic acid and galloyl derivatives of both glucose and quinic acid; (ii) flavonol glycosides, i.e. myricetin and quercetin glycosides; and (iii) anthocyanins, namely delphinidin 3- O -glucoside and cyanidin 3- O -glucoside. Low amounts of catechin were also detected. The concentration of galloyl derivatives was extremely high, representing 5.3% of the leaf dry weight, and appreciable amounts of myricetin derivatives were also detected (1.5% on a dry weight basis). These findings may be useful in establishing a relationship between the chemical composition of the leaf extract and the previously reported biological activity of P. lentiscus, and may also assign a new potential role of P. lentiscus tissue extracts in human health care. Copyright © 2002 John Wiley & Sons, Ltd. [source] Immune response modifiers , mode of actionEXPERIMENTAL DERMATOLOGY, Issue 5 2006Meinhard Schiller Abstract:, The innate immune system governs the interconnecting pathways of microbial recognition, inflammation, microbial clearance, and cell death. A family of evolutionarily conserved receptors, known as the Toll-like receptors (TLRs), is crucial in early host defense against invading pathogens. Upon TLR stimulation, nuclear factor-,B activation and the interferon (IFN)-regulatory factor 3 pathway initiate production of pro-inflammatory cytokines, such as interleukin-1 and tumor necrosis factor-,, and production of type I IFNs (IFN-, and IFN-,), respectively. The innate immunity thereby offers diverse targets for highly selective therapeutics, such as small molecular synthetic compounds that modify innate immune responses. The notion that activation of the innate immune system is a prerequisite for the induction of acquired immunity raised interest in these immune response modifiers as potential therapeutics for viral infections and various tumors. A scenario of dermal events following skin cancer treatment with imiquimod presumably comprises (i) an initial low amount of pro-inflammatory cytokine secretion by macrophages and dermal dendritic cells (DCs), thereby (ii) attracting an increasing number type I IFN-producing plasmacytoid DCs (pDCs) from the blood; (iii) Langerhans cells migrate into draining lymph nodes, leading to an increased presentation of tumor antigen in the draining lymph node, and (iv) consequently an increased generation of tumor-specific T cells and finally (v) an accumulation of tumoricidal effector cells in the treated skin area. The induction of predominately T helper (Th)1-type cytokine profiles by TLR agonists such as imiquimod might have further benefits by shifting the dominant Th2-type response in atopic diseases such as asthma and atopic dermatitis to a more potent Th1 response. [source] Cradling in the prevention of excessive crying and colic symptoms in infantsINFANT MENTAL HEALTH JOURNAL, Issue 3 2005Elina Hyödynmaa To evaluate lying in a cradle in the prevention of excessive infant crying or colic symptoms, and to investigate potential protective or risk factors for the phenomenon, 220 newborns were randomized to sleep either in a bed or cot (control group, N = 108) or in a cradle (cradle group, N = 112). During three months, the parents filled in diaries on the sleeping place most used and the amount of crying of their infants. Three infants in the cradle group and one control fulfilled the criteria of colic. The percentages of extremely weepy infants (25.7% vs 24.4 %) and the intensity of crying did not differ between the groups. Medication for colic symptoms was used equally frequently in both groups. A high educational (OR 3.18, 95% CI 1.01; 10.04) and socioeconomic (OR 3.76, 95% CI 1.34; 10.52) level of the family and having a sibling with a history of colic (OR 6.46, 95% CI 1.17; 35.73) were predictors for the infant being weepy. Absence of nursing problems and having no sibling with a history of colic seemed to be related with a low amount of crying. Excessive infant crying was less common in families with unemployed fathers compared to those in which the father had an occupation (p = 0.018). Cradling seems not to prevent excessive crying or colic symptoms in infants. Breast-feeding guidance during rooming-in period and presence of father or another adult supporter at home might be preventive means against excessive crying. [source] Molecular cloning of several rat ABC transporters including a new ABC transporter, Abcb8, and their expression in rat testisINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2006Nathalie Melaine Summary Several members of the ABC transporter superfamily play an important role in testicular physiology and defence against anticancer drugs. Using a reverse transcription-polymerase chain reaction strategy with degenerate primers and rat testis RNA as template, we have looked for the presence of other members of this superfamily. Of the six partial cDNA found, five corresponded to ABC transporters already known ,Mdr1b, Mrp1, Tapl/Abcb9, Umat/Abcb6 and Sur2/Abcc9, and one presented a strong homology with mouse and human ABCB8. Using a 5, and 3, RACE approach, we cloned the full-length cDNA and found that the predicted protein presented 92% and 80% homology with the mouse and human proteins respectively. Strong expression of rat abcb8 was found in heart, brain and testis when compared with liver, lung and spleen. In the testis, rat abcb8 was expressed both in the somatic Sertoli cells and peritubular cells and in the germline (spermatogonia and pachytene spermatocytes). Furthermore, Umat/Abcb6 was very highly expressed in the testis (high amounts in meiotic pachytene spermatocytes and low amount in post-meiotic early spermatids). In conclusion, we confirm the presence of several ABC transporters in the testis and also provide evidence of the presence of Abcb8 in the organ. [source] New efficient copper fluoride-based catalyst for enantioselective hydrosilylation of ketones in aerobic conditionsISRAEL JOURNAL OF CHEMISTRY, Issue 4 2001James Courmarcel A new copper(II) fluoride,chiral diphosphines catalytic system was developed. This one is very efficient and selective for the hydrosilylation of several substituted or unsubstituted aromatic ketones in so far as moderate to excellent enantioselectivities were obtained. An oxygen acceleration effect was observed that led us to propose a practical protocol with a low amount of catalyst. [source] Poly(lactic acid)-based biocomposites reinforced with kenaf fibersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Maurizio Avella Abstract Biodegradable thermoplastic-based composites reinforced with kenaf fibers were prepared and characterized. Poly(lactic acid) (PLA) was selected as polymeric matrix. To improve PLA/fibers adhesion, low amount of a proper reactive coupling agent, obtained by grafting maleic anhydride onto PLA, was added during matrix/fibers melt mixing. Compared with uncompatibilized composites, this compatibilization strategy induces a strong interfacial adhesion and a pronounced improvement of the mechanical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Identification of Biological Samples in a Case of Contamination of a Cytological Slide Preparation,JOURNAL OF FORENSIC SCIENCES, Issue 3 2008Anke Junge Ph.D. Abstract:, Here we report a case where a discrete section of the cytological slide preparation of a female individual was obviously contaminated with pleura liquid of a female tumor patient. Analysis of the cancerous pleura liquid and the healthy cells of the slide preparation showed different DNA profiles, indicating that the material originated from two different female individuals. The DNA profile of the cell mixture revealed a heterogenous pattern whereby the alleles could be assigned to the healthy and the tumor patient. Loss of heterozygosity (LOH) was observed in four of eight short tandem repeat systems for the pleura liquid and the cell mixture. Despite the low amount of DNA on the slide preparation and the occurrence of LOH, it was possible to clarify the case and to support the assumption that a drop of cancerous pleura liquid contaminated the cytological slide. [source] Red blood cells labelling with 99mTc-d,l-HMPAO: an alternative method for specific casesJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 10 2003F.J. Pérez Abstract The effectiveness of the classic methods for red blood cells (RBCs) labelling with 99mTc has been demonstrated in nuclear medicine. However, nuclear physicians have found, in certain circumstances, this diagnostic technique fails and poor quality images are obtained. In this work we report on an alternative method that is of useful in these occasions, for in vitro labelling RBCs with 99mTc-d,l-HMPAO complex. The study shows a high and reproducible labelling efficiency (94.14±0.38), using low amount of tin. The RBCs were isolated from plasma and other interfering blood cells before adding 99mTc-d,l-HMPAO. The tracer was retained and the elution rate from RBCs was low (less than 6% after 120 min). The preclinical results indicate that this new method could be a good alternative to the standard classic methods for specific cases. Copyright © 2003 John Wiley & Sons, Ltd. [source] Suppression of proinflammatory cytokines and induction of IL-10 in human monocytes after coxsackievirus B3 infectionJOURNAL OF MEDICAL VIROLOGY, Issue 4 2001P. Hofmann Abstract Coxsackievirus B3 (CVB3) causes acute and chronic myocarditis, which is accompanied by an intense mononuclear leukocyte infiltration. Because myocardial tissue damage may either result from viral infections or from a dysregulated immune response, the susceptibility of human monocytes and macrophages to CVB3 was examined in this study with regard to virus replication, virus persistence, and release of cytokines. Monocytes were infected by CVB3 as shown by the intracellular appearance of plus- and minus-strand viral RNA, which was also capable of persisting for more than 10 days. Fresh monocytes were not permissive for full virus replication whereas monocyte-derived macrophages yielded a low amount of new viruses, which led to cell death. Although CVB3 infection induced the mRNA for the proinflammatory cytokines tumor necrosis factor-alpha (TNF-,), interleukin (IL)-1, and IL-6, only little cytokine production occurred. When infected monocytes were stimulated in addition by lipopolysaccharides (LPS), cytokine production was partially suppressed. In striking contrast, IL-10 expression was strongly and persistently induced by CVB3 on the mRNA and the protein level. These data show a dysregulated cytokine response in CVB3-exposed human monocytes and macrophages, which is characterized by a suppression of proinflammatory cytokines and a dominance of IL-10. This viral strategy may aid CVB3, causing chronic myocardiopathy. J. Med. Virol. 64:487,498, 2001. © 2001 Wiley-Liss, Inc. [source] Copolymerization of vinyl acetate with 1-octene and ethylene by cobalt-mediated radical polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2007Rayna Bryaskova Abstract The cobalt-mediated radical polymerization of vinyl acetate was extended to copolymerization with 1-alkenes (ethylene or 1-octene). In agreement with the low amount of 1-alkene that could be incorporated into the copolymer, a gradient structure was predictable, but a rather low polydispersity was observed. A poly(vinyl acetate)- b -poly(octene) copolymer was also successfully synthesized, leading to a poly (vinyl alcohol)- b -poly(octene) amphiphilic copolymer upon the methanolysis of the poly (vinyl acetate) block. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2532,2542, 2007 [source] Synthesis of a Li- and Ta-Modified (K,Na)NbO3 Solid Solution by Mechanochemical ActivationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2008Tadej Rojac The synthesis of (K0.485Na0.485Li0.03)(Nb0.8Ta0.2)O3 from a mechanochemically activated powder is presented for the first time. Mechanochemical activation, followed by a single calcination step was found to be a powerful technique for synthesizing a homogeneous solid solution with a low amount of contaminant, coming from the milling equipment, and good electrical properties without the need for a multiple calcination procedure involving intermediate wet-milling steps, which are typically required in the conventional solid-state synthesis route. [source] Phytogenic resources of halophytes of Central Asia and their role for rehabilitation of sandy desert degraded rangelandsLAND DEGRADATION AND DEVELOPMENT, Issue 4 2009K. N. Toderich Abstract Based on soil characteristics, watertable level, mineral composition of plant biomass, morphological/reproductive traits and carbon discrimination values, a new concept for the classification of halophytes was developed. Six main groups of halophytes have been described within the desert flora of Central Asia. Significant changes on chemical contents of ions: Cl,, SO, HCO, Na+, K+, Ca2+ and Mg2+among 23 studied halophytic forage species were revealed. Alhagi pseudoalhagi, Poaceae spp., Artemisia diffusa containing minimum concentration of mineral ions were categorised as relatively more palatable and valuable feed for livestock on open grazing and as hay. Fresh biomass of forage species growing under highly saline soils sharply decreased with increasing of salinity gradient. Potassium concentration was found highest in Kochia scoparia, Agropyron desertorum, closely followed by Atriplex nitens, Suaeda salsa, while annuals Salsola spp., Bromus tectorum, Aeluropus littoralis, Tamarix hispida, Eremopyrum orientale, Agropyron desertorum contain low amount of mineral ions because excess of salts are exuded through salt glands present abundantly on the surface of the epidermis. Native and exotic, both C3 and C4, halophytes are suitable for reclamation of degraded lands have been proven very useful in demonstration trials. The fresh biomass of investigated C3 plants sharply decreased with the increasing of soil salinity gradient. An integrated Biosaline Agriculture model for sustainable and integrated use of marginal mineralised water resources and salt-affected soils through involvement of food,feed salt/drought tolerant crops and forage legumes to improve food security, alleviate poverty and enhance ecosystem health in smallholder crop,livestock systems has been demonstrated. Copyright © 2009 John Wiley & Sons, Ltd. [source] Toughening of Epoxy Resin by Methyl Methacrylate/2-Ethylhexyl Acrylate Copolymers: The Effect of Copolymer CompositionMACROMOLECULAR MATERIALS & ENGINEERING, Issue 12 2007Soraia Zaioncz Abstract MMA-EHA copolymers with different compositions and with a low amount of AA were synthesized and used as impact modifier for epoxy networks. The effect of the copolymers on the tensile and dynamic mechanical properties as well as impact resistance of the epoxy network was evaluated. The addition of 10 phr of low-molar-mass MMA-EHA copolymer with defined composition resulted in a significant increase in impact resistance without any significant changes in the tensile strength, modulus, and glass transition temperature. The morphology of the modified epoxy network depends upon the copolymer composition. [source] Investigation on the oxidation behaviour of gamma titanium aluminides coated with thermal barrier coatingsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 7 2008R. Braun Abstract In the present study, the applicability of thermal barrier coatings (TBCs) on ,-TiAl alloys was investigated. Two alloys with the chemical compositions of Ti-45Al-8Nb-0.2B-0.15C and Ti-45Al-1Cr-6Nb-0.4W-0.2B-0.5C-0.2Si were used. Before TBC deposition, the specimens were pre-oxidised in laboratory air or low partial pressure oxygen atmosphere. Yttria partially stabilised zirconia top coats were then deposited using electron-beam physical vapour deposition (EB-PVD). The oxidation behaviour of the ,-TiAl specimens with TBC was studied by cyclic oxidation testing in air at 850 and 900,°C. Post-oxidation analysis of the coating systems was performed using scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS). No spallation of the TBC was observed for pre-oxidised specimens of both alloys when exposed to air at 850,°C for 1100 cycles of 1,h dwell time at high temperature. SEM micrographs of the thermally grown oxide scale revealed outer mixed TiO2/Al2O3 protrusions with a columnar structure. The protrusions contained small particles of zirconia and a low amount of about 0.5 at% zirconium was measured by EDS analysis throughout this outer oxide mixture. The TBCs exhibited excellent adherence on the oxide scale. Intercolumnar gaps and pores in the root area of the TBC were filled with titania and alumina. Below the outer columnar oxide scale, a broad porous zone of predominant titania was observed. The transition region between the oxide scale and substrate consisted of a discontinuous nitride layer intermixed with alumina particles and intermetallic phases rich in niobium formed at the nitride layer/substrate interface. When thermally cycled at 900,°C, the oxide scales on the alloy Ti-45Al-8Nb-0.2B-0.15C pre-oxidised in low partial pressure oxygen spalled off after 540 cycles. For the sample with TBC, spallation was observed after 810 cycles. Failure occurred in the thermally grown oxide near the oxide/nitride layer interface. Microstructural examinations revealed again oxide scales with columnar structure beneath the zirconia top coat and good adherence of the TBC on the thermally grown oxides formed at 900,°C. [source] Platinum group elements in impactites of the ICDP Chicxulub drill core Yaxcopoil-1: Are there traces of the projectile?METEORITICS & PLANETARY SCIENCE, Issue 6 2004Roald Tagle These are the main elements used for projectile identification. They were determined by nickel sulfide fire assay combined with inductively coupled plasma mass spectrometry. The concentration of PGE in the samples are low. The concentration patterns of the suevite samples resemble the pattern of the continental crust. We conclude that any meteoritic fraction in these samples is below 0.05%. A syn- and post-impact modification of the PGE pattern from meteoritic toward a continental crust pattern is very unlikely. The globally distributed fallout at the Cretaceous-Tertiary (K/T) boundary, however, has high PGE concentrations. Therefore, the lack of a significant meteoritic PGE signature in the crater is not an argument for a PGE-poor impactor. Taking the results of three-dimensional numerical simulations of the Chicxulub event into account, the following conclusions are drawn: 1) The main fraction of the impactor was ejected into and beyond the stratosphere, distributed globally, and deposited in the K/T boundary clay; and 2) the low amount of projectile contamination in the Yax-1 lithologies may reflect an oblique impact. However, the role of volatiles in the mixing process between projectile and target is not well-understood and may also have played a fundamental role. [source] Consequences of forest fragmentation for polyporous fungi at two spatial scalesOIKOS, Issue 2 2006R. Penttilä Greatly reduced area of old-growth forests and the very low amount of dead wood in managed forests in northern Europe have caused a marked decline in the populations of saproxylic species. It is less clear at which spatial and temporal scales these adverse changes are taking place, and more information is needed to reliably predict which species are especially sensitive to loss and fragmentation of habitat. Here we compare species richness, incidence of occurrence in forest fragments, and abundance of polyporous fungal species and species groups between two regions in Finland with contrasting histories of forestry and a marked difference in the amount and spatial configuration of old-growth forests. We also analyse the consequences of increasing loss of connectivity on the presence and abundance of polypores in a study region with a documented short-term history of old-growth fragmentation. Our results show that the species number, incidence of occurrence, and abundance of especially the rare, threatened, and near-threatened species are much lower in the old-growth fragments in Häme in southern Finland in comparison with Kuhmo in eastern Finland, most probably because of the longer history of intensive forestry in Häme. Among the rare species, the species that show the greatest difference between the two regions (at the scale of 500 km) also tended to respond most strongly to the more recent forest fragmentation within the study region in Kuhmo (at the scale of 50 km). Polypores associated with spruce seem to be more strongly affected by forestry than species associated with pine, possibly reflecting the differences in the natural dynamics of spruce-dominated and pine-dominated forests. [source] Organoclay,natural rubber nanocomposites synthesized by mechanical and solution mixing methodsPOLYMER INTERNATIONAL, Issue 11 2004MA López-Manchado Abstract This investigation describes two methods to obtain rubber composites based on natural rubber (NR) and organophilic layered silicates. In order to improve the exfoliation and compatibilization of the organoclays with the rubber matrix, a new approach which involves swelling of the organoclays with an elastomer solution prior to compounding has been used. The effect of the addition during swelling of a coupling agent, namely bis(trietoxysilylpropyl)tetrasulfan (TESPT), on the behaviour of the composites was also investigated. The results show that a low amount of organoclay (10 phr) significantly improves the properties of natural rubber. This suggests a strong rubber,organoclay interaction which is attributed to a high degree of rubber intercalation into the nanosilicate galleries, as was confirmed from X-ray diffraction. In addition, an ulterior improvement in the properties of the nanocomposites prepared by solution mixing is clearly observed, due to the better filler,rubber compatibility. An even further increase in the properties is observed by treating the silicate with a silane coupling agent. The silane functional groups modify the clay surface, thus reducing the surface energy, and consequently improving the compatibility with the rubber matrix. Copyright © 2004 Society of Chemical Industry [source] Ways to Create New CHNO-Oxidizers for Stoichiometric Gas-Generating Compositions with Low Combustion TemperaturePROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 5 2007David Abstract The investigation is aimed to study the possibility of creation of new CHNO-oxidizers for smokeless gas-generating compositions for airbag inflators. For ensuring low amount of CO and nitrogen oxides in combustion products it is necessary to create stoichiometric compositions with a relatively low combustion temperature. Ways to create new oxidizers acceptable to this requirement are examined, mainly by introducing low-enthalpy oxygen-containing groups into the oxidizer molecule. Standard enthalpy of formation (,fH°) has been calculated for substances with unknown ,fH°, thermal stability has been qualitatively estimated, and combustion temperatures of stoichiometric compositions have been calculated. [source] Effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and visceral organ growth of suckling calvesANIMAL SCIENCE JOURNAL, Issue 6 2009Mitsuru KAMIYA ABSTRACT The objective was to evaluate effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and allometric growth of visceral organs in suckling calves. Holstein bull calves (n = 8; 3,4 days of age) were fed either a low amount (average 0.63 kgDM/day, LM) or high amount (average 1.15 kgDM/day, HM) of high protein milk replacer until they were slaughtered at 6 weeks of age. Body weight (BW) at 4, 5, and 6 weeks of age, feed intake, average daily gain, and feed efficiency were higher in the HM than LM calves. The HM group had higher plasma glucose at 3 and 4 weeks of age and insulin levels after the age of 4 weeks compared with LM calves whereas no effect was detected on plasma nonesterified fatty acid or urea nitrogen concentrations. The HM calves had greater empty body weight (EBW), viscera-free BW and most of the organs dissected than LM calves. Relative weights (% of EBW) of liver, spleen, kidneys, and internal fat were higher, whereas head and large intestine was lower in HM than LM calves. The results suggest that increased milk feeding levels would accelerate the growth of the body and specific organs. [source] Iron balance and iron nutrition in infancyACTA PAEDIATRICA, Issue 2003G Faldella At birth, the total body iron content is approximately 75 mg/kg, twice that of an adult man in relation to weight. During the first 6 mo of life, total iron body content increases slightly and exclusive breastfeeding is sufficient to maintain an optimal iron balance. Thereafter, iron body content substantially increases and the infant becomes critically dependent on dietary iron, provided by complementary foods. Numerous factors may contribute to nutritional iron deficiency in infancy, the most important being low body iron content at birth, blood loss, high postnatal growth rate, and a low amount and/or bioavailability of dietary iron. We have documented that the prevalence of iron deficiency declined in Italy as iron nutrition improved and that early feeding on fresh cow's milk is the single most important determinant of iron deficiency in infancy. Healthy full-term infants should maintain optimal iron balance by consuming a good diet, which can be summarized as follows: breastfeeding should be continued exclusively for at least 5 mo and then together with complementary foods containing highly bioavailable iron; infants who are not breastfed or are partially breastfed should receive an iron-fortified formula, containing between 4.0 and 8.0mg/L iron, from birth to 12 mo of age; fresh cow's milk should be avoided before 12 mo of age. [source] Landscape composition influences patterns of native and exotic lady beetle abundanceDIVERSITY AND DISTRIBUTIONS, Issue 4 2009M. M. Gardiner Abstract Aim, Coccinellid beetles are important predators that contribute to pest suppression in agricultural landscapes. Since the introduction of the exotic coccinellids Coccinella septempunctata L. and Harmonia axyridis Pallas into the USA, several studies have reported a decline of native Coccinellidae in agroecosystems. We aimed to investigate the influence of landscape composition on native and exotic coccinellid abundance within soybean fields. Location, Iowa, Michigan, Minnesota and Wisconsin. Methods, As part of a 2-year study (2005,06) on the biological control of the soybean aphid, Aphis glycines Matsumura, we examined coccinellid communities in 33 soybean fields using yellow sticky card traps. Landscape heterogeneity and composition were measured at multiple spatial scales ranging 1,3.5 km from focal soybean fields where coccinellid sampling took place. Results, Exotic species made up 90% of the total coccinellid community in Michigan soybean fields followed by Wisconsin (84%), Minnesota (66%) and Iowa (57%). Harmonia axyridis was the dominant exotic coccinellid in all states comprising 45,62% of the total coccinellid community, followed by C. septempunctata (13,30%). Two additional exotic species, Hippodamia variegata (Goeze) and Propylea quatuordecimpunctata (L.) were also found in the region. Overall, the most abundant native coccinellid was Hippodamia convergens Guerin-Meneville; however, its abundance varied across the region, comprising 0% (Michigan) to 28% (Iowa) of the total coccinellid community. Landscape structure significantly influenced the composition of coccinellid communities in soybean agroecosystems. We found that native coccinellids were most abundant in low-diversity landscapes with an abundance of grassland habitat while exotic coccinellids were associated with the abundance of forested habitats. Main conclusion, We propose that grassland dominated landscapes with low structural diversity and low amounts of forested habitat may be resistant to exotic coccinellid build-up, particularly H. axyridis and therefore represent landscape-scale refuges for native coccinellid biodiversity. [source] Wood storage in a wide mountain river: case study of the Czarny Dunajec, Polish CarpathiansEARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2005omiej Wy Abstract Storage of large woody debris in the wide, mountain, Czarny Dunajec River, southern Poland, was investigated following two floods of June and July 2001 with a seven-year frequency. Within a reach, to which wood was delivered only by bank erosion and transport from upstream, wood quantities were estimated for eighty-nine, 100 m long, channel segments grouped into nine sections of similar morphology. Results from regression analysis indicated the quantity of stored wood to be directly related to the length of eroded, wooded banks and river width, and inversely related to unit stream power at the flood peak. The largest quantities of wood (up to 33 t ha,1) were stored in wide, multi-thread river sections. Here, the relatively low transporting ability of the river facilitated deposition of transported wood while a considerable length of eroded channel and island banks resulted in a large number of trees delivered from the local riparian forest. In these sections, a few morphological and ecological situations led to the accumulation of especially large quantities of wood within a small river area. Very low amounts of wood were stored in narrow, single-thread sections of regulated or bedrock channel. High stream power facilitated transport of wood through these sections while the high strength of the banks and low channel sinuosity prevented bank retreat and delivery of trees to the channel. Considerable differences in the character of deposited wood existed between wide, multi-thread channel sections located at different distances below a narrow, 7 km long, channellized reach of the river. Wood deposited close to the downstream end of the channellized reach was highly disintegrated and structured into jams, whereas further downstream well preserved shrubs and trees prevailed. This apparently reflects differences in the distance of wood transport and shows that in a mountain river wider than the height of trees growing on its banks, wood can be transported long distances along relatively narrow, single-thread reaches but is preferentially deposited in wide, multi-thread reaches. Copyright © 2005 John Wiley & Sons, Ltd. [source] Dynamic coating of SU-8 microfluidic chips with phospholipid disksELECTROPHORESIS, Issue 15 2010Tiina Sikanen Abstract In this work, PEG-stabilized phosphatidylcholine lipid aggregates (disks), mimicking mammalian cell membranes, were introduced as a new biofouling resistant coating for SU-8 polymer microchannels. A rapid and simple method was developed for immobilization of PEGylated phosphatidylcholine disks in microchannels. Microfluidic chips made from SU-8, PDMS, or glass were dynamically coated with the PEGylated disks followed by characterization of their surface chemistry before and after coating. On the basis of the observed changes in EOF and nonspecific protein adsorption, the affinity of the PEGylated disks was shown to be particularly strong toward SU-8. The PEG-lipid coating enabled permanent change in EOF in SU-8 microchannels with an initial value of 4.5×10,8,m2,V,1,s,1, decreasing to 2.1×10,8,m2,V,1,s,1 (immediately after modification), and, eventually, to 1.5×10,8,m2,V,1,s,1 (7 days after modification) for 9,mM sodium borate (pH 10.5) as BGE. As determined by the Wilhelmy plate measurements and microchip-CE analysis of BSA, the PEG-lipid coating also enabled efficient biofouling shield against protein adsorption, similar to that of low amounts of SDS (3.5,mM) or Tween-20 (80,,M) as buffer additives. These results suggest that dynamically attached PEG-lipid aggregates provide stable, biomimicking surface modification that efficiently reduces biofouling on SU-8. [source] A novel ultra-sensitive method for the quantification of glycosaminoglycan disaccharides using an automated DNA sequencerELECTROPHORESIS, Issue 7 2006Kay Vogel Abstract Analysis of glycosaminoglycans (GAGs) is of increasing importance concerning alterations in extracellular matrix composition and selectivity of glomerular basement membrane. In this report we describe the analysis of chondroitin sulfate disaccharides as an example of GAG ,disaccharide analysis using standard DNA sequencing equipment (DNA sequencer-assisted GAG disaccharide separation, DSA-GAGS). The presented methodology allows nanomolar quantification of 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-derived GAG disaccharides. In comparison to RP-HPLC the established method is much more sensitive, showing detection limits of 38,fmol/,L. Variation coefficients were approximately 10%, enabling exact quantifications after run times of 17,min at 30°C and an electrophoresis voltage of 15,kV; using a capillary DNA sequencer, available in many molecular laboratories, presented advantages like automated sample injection, opportunity of high-throughput analyses, separation of even sulfated disaccharide epimers, and the possibility of using APTS-derived fucose as an internal standard. Furthermore, highly reproducible retention times rendered easy identification of specific signals (SD,0.02). With regard to these results, the described method is a useful tool for the quantification of GAG disaccharides in low amounts, indicating advantages of obverse RP-HPLC and slab gel polyacrylamide electrophoresis in sensitivity, error-proneness, automation, and handling. [source] Dynamics of Benzene and Toluene Degradation in Pseudomonas putida F1 in the Presence of the Alternative Substrate SuccinateENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2007I. Rüegg Abstract In batch and continuous culture, the regulation of benzene and toluene degradation by Pseudomonas putida,F1 was investigated in the presence of the alternative carbon and energy source succinate. In batch culture, benzene and toluene were used simultaneously, whereas succinate suppressed benzene consumption under carbon excess conditions resulting in diauxic growth. In carbon-limited continuous culture mixed substrate growth was observed. Since in nature low substrate concentrations and ever changing conditions prevail, this paper focuses on the dynamics of benzene/toluene degradation, biomass synthesis, and the regulation of benzene/toluene-degrading enzymes in cultures growing continuously at a dilution rate of 0.1,h,1, when shifting the supply of the carbon and energy source from succinate to various mixtures of succinate and benzene/toluene, or to benzene only. When the succinate concentration was kept constant (1.25,mM) and the medium was supplemented with benzene (2,mM), growth with benzene began already two hours after the shift. In contrast, replacing succinate with benzene only led to a wash out of biomass for more then ten hours, before biomass production from benzene started. A striking and reproducible transition pattern was observed for all shifts where the succinate concentration was reduced or succinate was omitted. After an initial period of biomass production from benzene, the culture collapsed and a wash-out of biomass was observed. However, this wash-out was not accompanied by an increase in benzene in the cultivation liquid, indicating a benzene uptake without conversion into biomass. Another possibility is that in phases of low biomass concentrations, cells were only able to use the low amounts of benzene/toluene dissolved in the cultivation liquid yielding low biomass concentrations whereas in phases of high biomass concentrations, they were able to rapidly utilize the aromatic solvents so that additional benzene from the gas phase diffused into the cultivation liquid resulting in more biomass production. In most cases, growth resumed again after 10 to 80,h. Currently, the reasons for the decrease in biomass after the first rise are unknown. However, several indications rule out intoxication of the cells by either the solvents benzene or toluene themselves, or by toxic degradation intermediates, or by-products. [source] Heat Shock Protein-27 Is Upregulated in the Temporal Cortex of Patients with EpilepsyEPILEPSIA, Issue 12 2004Hans-J Bidmon Summary:,Purpose: Heat shock protein-27 (HSP-27) belongs to the group of small heat shock proteins that become induced in response to various pathologic conditions. HSP-27 has been shown to protect cells and subcellular structures, particularly mitochondria, and serves as a carrier for estradiol. It is a reliable marker for tissues affected by oxidative stress. Oxidative stress and related cellular defence mechanisms are currently thought to play a major role during experimentally induced epileptic neuropathology. We addressed the question whether HSP-27 becomes induced in the neocortex resected from patients with pharmacoresistant epilepsy. Methods: Human epileptic temporal neocortex was obtained during neurosurgery, and control tissue was obtained at autopsy from subjects without known neurologic diseases. The tissues were either frozen for Western blot analysis or fixed in Zamboni's fixative for the topographic detection of HSP-27 at the cellular level by means of immunohistochemistry. Results: HSP-27 was highly expressed in all epilepsy specimens and in the cortex of a patient who died in the final stage of multiple sclerosis (positive control), whereas only low amounts of HSP-27 were detectable in control brains. In epilepsy patients, HSP-27 was present in astrocytes and in the walls of blood vessels. The intracortical distribution patterns varied strongly among the epilepsy specimens. Conclusions: These results demonstrate that HSP-27 becomes induced in response to epileptic pathology. Although the functional aspects of HSP-27 induction during human epilepsy have yet to be elucidated, it can be concluded that HSP-27 is a marker for cortical regions in which a stress response has been caused by seizures. [source] CD4+ T cell help improves CD8+ T cell memory by retained CD27 expressionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2008Matthias Abstract CD4+ T cell help during the priming of CD8+ T lymphocytes imprints the capacity for optimal secondary expansion upon re-encounter with antigen. Helped memory CD8+ T cells rapidly expand in response to a secondary antigen exposure, even in the absence of T cell help and, are most efficient in protection against a re-infection. In contrast, helpless memory CTL can mediate effector function, but secondary expansion is reduced. How CD4+ T cells instruct CD8+ memory T cells during priming to undergo efficient secondary expansion has not been resolved in detail. Here, we show that memory CTL after infection with lymphocytic choriomeningitis virus are CD27high whereas memory CTL primed in the absence of CD4+ T cell have a reduced expression of CD27. Helpless memory CTL produced low amounts of IL-2 and did not efficiently expand after restimulation with peptide in vitro. Blocking experiments with monoclonal antibodies and the use of CD27,/, memory CTL revealed that CD27 ligation during restimulation increased autocrine IL-2 production and secondary expansion. Therefore, regulating CD27 expression on memory CTL is a novel mechanism how CD4+ T cells control CTL memory. [source] Regulation of the norepinephrine transporter by ,-synuclein-mediated interactions with microtubulesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2007Alexis M. Jeannotte Abstract ,-Synuclein (,-Syn) regulates catecholaminergic neurotransmission. We demonstrate that ,-Syn regulates the activity and surface expression of the norepinephrine transporter (NET), depending on its expression levels. In cells co-transfected with NET and low amounts of ,-Syn, NET activity and cell surface expression were increased and protein interactions with ,-Syn decreased, compared with cells transfected with NET alone. Converse effects were observed at higher levels of ,-Syn expression. Treatment with nocodazole and other microtubule (MT) destabilizers abolished the expression-dependent bimodal regulation of NET by ,-Syn. At low ,-Syn levels, nocodazole had no effect on NET surface expression or protein interactions, while inducing increases in these measures at higher levels. Cells that were transfected with NET alone displayed no sensitivity to nocodazole, indicating that ,-Syn expression was necessary for the MT-dependent changes in NET activity. MT destabilizers also caused a significant increase in [3H]-NE uptake in brainstem primary neurons and synaptosomes from the frontal cortex, but not striatal synaptosomes. These findings suggest that the surface localization and activity of NET is modulated by ,-Syn in a manner that is both dependent on interactions with the MT cytoskeleton and varies across brain regions. [source] Interleukin-6-induced proliferation of pre-B cells mediated by receptor complexes lacking the SHP2/SOCS3 recruitment sites revisitedFEBS JOURNAL, Issue 24 2001Kerstin Friederichs Interleukin-6 (IL-6) induces B-cell proliferation by binding to receptor complexes composed of a specific ,-receptor (gp80; CD126) and the signal transducing receptor subunit gp130 (CD130). Immediately after receptor complex activation, signal transducers and activators of transcription (STATs) 1 and 3 and the Src-homology domain-containing protein tyrosine phosphatase 2 (SHP2) are recruited to gp130 and subsequently tyrosine phosphorylated. The activated dimerized STATs translocate to the nucleus and bind to enhancer elements of IL-6-inducible genes. SHP2 acts as an adapter and links the Jak/STAT pathway to the Ras/Raf/MAPK cascade but it is also involved in signal attenuation. Whereas STAT3 activation appears to be crucial for all biological activities of IL-6, the requirement of SHP2-activation depends on the individual biological response analyzed. The requirement of SHP2 activation for the pre-B cell (Ba/F3) proliferation has been reported previously [Fukada, T., Hibi, M., Yamanaka, Y., Takahashi-Tezuka, M., Fujitani, Y., Yamaguchi, T., Nakajima, K. & Hirano, T. (1996) Immunity5, 449,460]. In contrast, we have recently demonstrated that the presence of a single STAT-recruitment site within gp130 is sufficient for IL-6- induced proliferation of Ba/F3 cells [Schmitz, J., Dahmen, H., Grimm, C., Gendo, C., Müller-Newen, G., Heinrich, P.C. & Schaper, F. (2000) J. Immunol.164, 848,854]. To unravel this discrepancy we analyzed the IL-6-induced dose-dependent proliferation of Ba/F3 cells mediated by receptor complexes lacking SHP2/SOCS3 recruitment sites. Surprisingly, pre-B cells, after stimulation with low amounts of IL-6, proliferate much more efficiently in the absence of the activated SHP2 than in the presence of the tyrosine phosphatase. Therefore, SHP2 activation appears to be relevant for IL-6-induced proliferation only after stimulation with very large amounts of IL-6. [source] | ||||||||||||||||||||||||||||