bluuebunny/crossref_metadata_2025_split huggingface dataset:
An amphiphilic region in the cytoplasmic domain of KdpD is recognized by the signal recognition particle and targeted to the Escherichia coli membrane
Authors: Maier Katja S. , Hubich Stefanie , Liebhart Helga , Krauss Susanne , Kuhn Andreas , Facey Sandra J. 
Published: April 2008

SummaryThe sensor protein KdpD of Escherichia coli is composed of a large N‐terminal hydrophilic region (aa 1–400), four transmembrane regions (aa 401–498) and a large hydrophilic region (aa 499–894) at the C‐terminus. KdpD requires the signal recognition particle (SRP) for its targeting to the membrane. Deletions within KdpD show that the first 50 residues are required for SRP‐driven membrane insertion. A fusion protein of the green fluorescent protein (GFP) with KdpD is found localized at the membrane only when SRP is present. The membrane targeting of GFP was not observed when the first 50 KdpD residues were deleted. A truncated mutant of KdpD containing only the first 25 amino acids fused to GFP lost its ability to specifically interact with SRP, whereas a specific interaction between SRP and the first 48 amino acids of KdpD fused to GFP was confirmed by pull‐down experiments. Conclusively, a small amphiphilic region of 27 residues within the amino‐terminal domain of KdpD (aa 22–48) is recognized by SRP and targets the protein to the membrane. This shows that membrane proteins with a large N‐terminal region in the cytoplasm can be membrane‐targeted early on to allow co‐translational membrane insertion of their distant transmembrane regions.
Plasmodium falciparum antigenic variation. Mapping mosaic var gene sequences onto a network of shared, highly polymorphic sequence blocks
Authors: Bull Peter C. , Buckee Caroline O. , Kyes Sue , Kortok Moses M. , Thathy Vandana , Guyah Bernard , Stoute José A. , Newbold Chris I. , Marsh Kevin 
Published: April 2008

Summary Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a potentially important family of immune targets, encoded by an extremely diverse gene family called var. Understanding of the genetic organization of var genes is hampered by sequence mosaicism that results from a long history of non‐homologous recombination. Here we have used software designed to analyse social networks to visualize the relationships between large collections of short var sequences tags sampled from clinical parasite isolates. In this approach, two sequences are connected if they share one or more highly polymorphic sequence blocks. The results show that the majority of analysed sequences including several var‐like sequences from the chimpanzee parasite Plasmodium reichenowi can be either directly or indirectly linked together in a single unbroken network. However, the network is highly structured and contains putative subgroups of recombining sequences. The major subgroup contains the previously described group A var genes, previously proposed to be genetically distinct. Another subgroup contains sequences found to be associated with rosetting, a parasite virulence phenotype. The mosaic structure of the sequences and their division into subgroups may reflect the conflicting problems of maximizing antigenic diversity and minimizing epitope sharing between variants while maintaining their host cell binding functions.
Ancestral roles of eukaryotic frataxin: mitochondrial frataxin function and heterologous expression of hydrogenosomal Trichomonas homologues in trypanosomes
Authors: Long Shaojun , Jirků Milan , Mach Jan , Ginger Michael L. , Sutak Robert , Richardson Des , Tachezy Jan , Lukeš Julius 
Published: April 2008

SummaryFrataxin is a small conserved mitochondrial protein; in humans, mutations affecting frataxin expression or function result in Friedreich's ataxia. Much of the current understanding of frataxin function comes from informative studies with yeast models, but considerable debates remain with regard to the primary functions of this ubiquitous protein. We exploit the tractable reverse genetics of Trypanosoma brucei in order to specifically consider the importance of frataxin in an early branching lineage. Using inducible RNAi, we show that frataxin is essential in T. brucei and that its loss results in reduced activity of the marker Fe–S cluster‐containing enzyme aconitase in both the mitochondrion and cytosol. Activities of mitochondrial succinate dehydrogenase and fumarase also decreased, but the concentration of reactive oxygen species increased. Trypanosomes lacking frataxin also exhibited a low mitochondrial membrane potential and reduced oxygen consumption. Crucially, however, iron did not accumulate in frataxin‐depleted mitochondria, and as T. brucei frataxin does not form large complexes, it suggests that it plays no role in iron storage. Interestingly, RNAi phenotypes were ameliorated by expression of frataxin homologues from hydrogenosomes of another divergent protist Trichomonas vaginalis. Collectively, the data suggest trypanosome frataxin functions primarily only in Fe–S cluster biogenesis and protection from reactive oxygen species.
Amino acid‐dependent growth of Campylobacter jejuni: key roles for aspartase (AspA) under microaerobic and oxygen‐limited conditions and identification of AspB (Cj0762), essential for growth on glutamate
Authors: Guccione Edward , Del Rocio Leon‐Kempis Maria , Pearson Bruce M. , Hitchin Edward , Mulholland Francis , Van Diemen Pauline M. , Stevens Mark P. , Kelly David J. 
Published: April 2008

SummaryAmino acids are key carbon and energy sources for the asaccharolytic food‐borne human pathogen Campylobacter jejuni. During microaerobic growth in amino acid rich complex media, aspartate, glutamate, proline and serine are the only amino acids significantly utilized by strain NCTC 11168. The catabolism of aspartate and glutamate was investigated. An aspartase (aspA) mutant (unable to utilize any amino acid except serine) and a Cj0762c (aspB) mutant lacking aspartate:glutamate aminotransferase (unable to utilize glutamate), were severely growth impaired in complex media, and an aspA sdaA mutant (also lacking serine dehydratase) failed to grow in complex media unless supplemented with pyruvate and fumarate. Aspartase was shown by activity and proteomic analyses to be upregulated by oxygen limitation, and aspartate enhanced oxygen‐limited growth of C. jejuni in an aspA‐dependent manner. Stoichiometric aspartate uptake and succinate excretion involving the redundant DcuA and DcuB transporters indicated that in addition to a catabolic role, AspA can provide fumarate for respiration. Significantly, an aspA mutant of C. jejuni 81‐176 was impaired in its ability to persist in the intestines of outbred chickens relative to the parent strain. Together, our data highlight the dual function of aspartase in C. jejuni and suggest a role during growth in the avian gut.
Trichomonas vaginalis‐induced neutrophil apoptosis causes anti‐inflammatory cytokine production by human monocyte‐derived macrophages
Authors: AHN M. H. , SONG H. O. , RYU J. S. 
Published: April 2008

SUMMARY Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with a Trichomonas vaginalis infection. Neutrophils have a shorter life span than other leucocytes. Our previous study indicated that live T. vaginalis alters Mcl‐1 expression and caspase‐3 activation, thereby inducing apoptosis of human neutrophils. However, it was previously unknown that the apoptotic neutrophils brought about by T. vaginalis can influence vaginal inflammation. Thus, human monocyte‐derived macrophages (HMDM) were incubated with T. vaginalis‐induced apoptotic neutrophils. Cytokine production and phagocytosis by HMDM were evaluated by ELISA and myeloperoxidase stain, respectively. HMDM showed increased anti‐inflammatory cytokine production (IL‐10) and decreased levels of pro‐inflammatory cytokines, such as TNF‐α and IL‐6, compared with macrophages alone. Therefore, these results suggest that apoptotic neutrophils caused by T. vaginalis may lead to the resolution of vaginal inflammation by anti‐inflammatory cytokine production in the human macrophages.
Toxocara canis larval excretory/secretory proteins impair eosinophil‐dependent resistance of mice to Nippostrongylus brasiliensis
Authors: GIACOMIN P. R. , CAVA M. , TUMES D. J. , GAULD A. D. , IDDAWELA D. R. , MCCOLL S. R. , PARSONS J. C. , GORDON D. L. , DENT L. A. 
Published: April 2008

SUMMARY Survival of parasitic helminths within a host requires immune evasion and excretory/secretory (ES) proteins may contribute to this process. Eosinophils are important effector cells in immunity of mice to the nematode Nippostrongylus brasiliensis and eosinophilic interleukin‐5 transgenic (IL‐5 Tg) mice are highly resistant to the earliest stages of primary infections. In contrast, Toxocara canis is largely resistant to eosinophils, with viable larvae encysted in tissues often surrounded by these and other leucocytes. The aim of this study was to investigate whether T. canis ES (TES) proteins inhibit eosinophil‐dependent resistance to N. brasiliensis. Mouse serum pre‐treated with TES had reduced capacity to mediate the adherence of leucocytes to N. brasiliensis infective‐stage larvae (L3) and this correlated with reduced complement C3 deposition on the parasite. TES did not inhibit eosinophil survival or eotaxin‐dependent eosinophil migration in vitro. Cellular inflammation and eosinophil degranulation in the skin in response to injection of L3 was also not impaired by TES. However, when TES was included with L3 in an inoculum given to IL‐5 Tg mice, a greatly increased number of parasites migrated to the lung. This suggests that the early eosinophil‐dependent resistance in these mice was suppressed, by mechanisms yet to be determined.
Liposome‐Encapsulated Antigens Induce a Protective CTL Response against Listeria monocytogenes Independent of CD4+ T Cell Help
Authors: Grenningloh R. , Darj A. , Bauer H. , Zur Lage S. , Chakraborty T. , Jacobs T. , Weiss S. 
Published: April 2008

AbstractProtection against intracellular pathogens is usually mediated by cytotoxic T lymphocytes (CTL). Induction of a protective CTL response for vaccination purposes has proven difficult because of the limited access of protein antigens or attenuated pathogens to the MHC class I presentation pathway. We show here that pH‐sensitive PE/CHEMS liposomes can be used as a vehicle to efficiently deliver intact proteins for presentation by MHC class I. Mice immunized with listerial proteins encapsulated in such liposomes launched a strong CTL response and were protected against a subsequent challenge with L. monocytogenes. Remarkably, the CTL response was induced independently of detectable CD4+ T cell help.
Oestrogen‐dependent hereditary angio‐oedema with normal C1 inhibitor: description of six new cases and review of pathogenic mechanisms and treatment
Authors: Serrano C. , Guilarte M. , Tella R. , Dalmau G. , Bartra J. , Gaig P. , Cerdà M. , Cardona V. , Valero A. 
Published: April 2008

Background:  Hereditary angio‐oedema (HAE) is a rare condition in which there is a deficiency in the quantity or activity of C1 inhibitor (C1INH). Recently, an additional type of HAE with no alterations in the levels or the function of C1INH has been reported. It is defined as HAE with normal C1INH, and named type III HAE or oestrogen‐dependent HAE. The aim of this study is to describe the clinical and laboratory findings of six new cases of type III HAE and to review the literature about this disease.Methods:  A short description of six women with recurrent angio‐oedema is provided. The characteristics of the patients are compared with the previously reported case series in a literature‐based review.Results:  The mean age of the patients at onset was 22 years (range 16–30). All of them had angio‐oedema attacks during oestrogen‐based contraceptive treatment and four reported episodes during pregnancy. Four patients reported a positive past family history. Two of them had experienced episodes of laryngeal oedema. None of the patients responded to corticoids or antihistamines during the attacks. Levels and functional activity of C1INH were within the normal range in all cases.Conclusions:  Clinical and laboratory findings mirror the observations of previous reports of oestrogen‐dependent angio‐oedema with normal C1INH. This is the first published series of type III HAE in Spain.
Veränderungen des bodenbürtigen Mineralstickstoffs im Frühjahr und seine Bedeutung für die Bemessung der N‐Düngung von Zuckerrüben
Authors: Maidl F. X. , Fischbeck G. 
Published: April 2008

Abstract Dynamics of inorganic soil nitrogen during spring and its importance for N‐fertilizer management in cultivation of sugar beets High sugar yield depends very much upon application of the correct dose of nitrogen fertilizer. To determine fertilizer needs in sugar beet cultivation two methods – Nmin and EUF – are discussed at present. Both methods are criticized not to be able to take into account the amount of soil nitrogen which becomes available between the early date of soil analysis and actual nutrient uptake in the sugar beet stands.The objective of this study was to investigate the influence of varying N‐mineralisation rates on growth and yield of sugar beets and corresponding changes in N‐fertilizer requirements.The differences in soil nitrate content in February showed no relation to the amount on N available during the early vegetation period. Therefore very low correlation coefficients were observed between soil nitrate content in early spring (February/March) and sugar yield (R2 > 0.2). However highly significant correlation coefficients were obtained for NO3‐N‐content in April/May in the 0—60 cm soil layer and sugar yield (R2= 0.62—0.78). Maximum sugar yield was obtained with 220 kg N/ha soil nitrat content in April/May in 0—‐60 cm. A wide N‐optimum range for maximal sugar yield was observed. Deviations less than 50 kg N/ha from the optimal N amount caused no significant changes in sugar yield.Higher amounts of late available nitrogen deposited at greater soil depths caused a decrease in sugar content and an increase in alpha‐amino‐N and sodium. Early applications of nitrogen fertilizer (before sowing) are endangered to be leached to lower depths with heavy rain falls and therefore may cause detrimental effects on juice purity and sugar content. For obtaining maximal sugar yield it is recommended to apply N‐fertilizer 1 or 2 weeks after and not before seeding.Related to the wide optimum of N‐requirement ist seems possible to determine the use of Nitrogen fertilizer according to local experience. In special cases (slurry, tillage of wet soils, preceeding vegetables or legumes) it is suggested to determine NO3‐N‐content in April (0—60 cm) and to apply nitrogen fertilizer supplementary to 220 kg N/ha.
Seasonal Changes in Nitrate Reductase Activity and Nitrogen Contents of Upland Rice at Low and Optimum N Fertility
Authors: Pal S. K. , Pal U. R. 
Published: April 2008

AbstractA field experiment was conducted at the Livestock Research Centre of G. B. Pant University of Agriculture and Technology, Pantnagar, India during the wet season (June—October) of 1980 with the objectives of characterizing the seasonal changes in in vivo nitrate reductase activity (NRA) and N contents of upland rice cultivars grown under rainfed condition at low (0 kg N/ha) and optimum (80 kg N/ha) N fertility. In vivo NRA increased initially up to panicle initiation stage (50 days after sowing) and declined, thereafter, until 90 days. Leaf NO3‐N content paralleled with in vivo NRA throughout crop season. Total N content of leaves and stem declined with advance in crop age, whereas panicle N content increased with the crop development. Optimum N fertility (80 kg N/ha) always resulted in higher NRA, NO−3 and total N contents of rice plants.
Combining Ability for Grain Yield and other Agronomic Characters in Rice
Authors: Sasmal B. , Banerjee S. P. 
Published: April 2008

AbstractA diallel analysis to identify parental lines and specific crosses through combining ability estimation was undertaken in a set of seven rice varieties. Griffing's Method I, Model I was employed for this purpose. The seven parents and 42 F1s (including reciprocals) were grown in a randomized block design with four replications. Data were collected on 16 characters including a few root characters for which requisite number of plants were grown (in RBD design) in pot culture.GCA and SCA variances were significant for all the characters. Reciprocal effects were also significant except for rachilla/panicle and grain length. An early flowering NC 1281 Mutant and Taichung Native 1: bold grain mutant were good general combiners for majority of characters. The crosses with high specific combining ability generally involved high × low general combiners. The cross Nira × T‐N‐1: bold grain mutant recorded best SCA effects for grain yield as well as all the important yield attributes and also for major root characters. In fact, in most of the high SCA registering crosses for various characters, Taichung Native 1: bold grain mutant or Nira was one of the parents commonly involved.
Das Kompensationsvermögen der Weizenähre in Abhängigkeit vom Temperaturniveau während der Kornausbildungsperiode
Authors: Aufhammer W. , Hannappel U. 
Published: April 2008

Abstract Compensation capacity of wheat ears depending on temperature level during grain‐filling period In order to investigate the compensation capacity, effects of sterilization treatments on dry matter storage within spikelets and florets of wheat ears, growing in different temperatures during grain‐filling period were tested. Alternatively proximal or distal florets from 6 spikelets in the central region were removed at different stages. — Grain weight/ear remained 40% smaller in the high compared with the low temperature level. With high temperature sterilization of proximal florets allowed more additional florets in distal positions to develop grains than with low temperature. Beyond of this in both levels single grain weights in the basal and the apical region of the ear increased. Compensation effects, especially by additional grains decreased as later the treatments were done. Relatively the grain weight loss by sterilization was compensated to a higher degree in high than in low temperatures.
Observations of Effects of Partial Vernalization in Winter Rape Plants Grafted Onto Generative Stock
Authors: Filek W. , Pienkowski S. , Dubert F. 
Published: April 2008

AbstractWinter rape plants vernalized under natural conditions were used as stock for grafting apical and subapical parts of rape seedlings vernalized at 5 °C in light during different periods ranging from 0 to 10 weeks. Acceleration of generative development in both kinds of grafts occurred already after 3 weeks of their vernalization, i.e. after cold treatment of insufficient length to induce flowering in plants developing independently. Effectiveness of vernalization — measured by acceleration of flowering in grafts was highest from 3rd to 5th week of cold treatment and then it declined. Processes occurring during an early stage of vernalization, though insufficient to allow independent generative development, become manifest in grafts made on vernalized stock. This allows investigations of very early stages of vernalization processes inaccessible to observation by other methods.
Effect of Field Bean and Soybean Cultivation on Soil Compaction Amelioration and its Influence on Wheat and Barley as subsequent Crops
Authors: Kahnt G. , Hijazi L. A. , Rao M. 
Published: April 2008

Abstract Effect of field bean and soybean cultivation on soil compaction amelioration and its influence on wheat and barley as subsequent crops Amelioration effect of field bean and soybean growth on compacted soil and its influence on the following crops of wheat and barley was tested. The performance of both field bean and soybean was affected by compaction. A reduction of 5–16 % in total dry matter, 10–22 % in seed yield, 5–12 % in no. of pods per plant, 4–14 % in plant height, 8–19 % in total accumulated N in plant and 11–22 % in accumulated N in seed of the both crops was registered. The crops were grown at 30 and 60 plants/m2 densities. The negative effects of compaction were compensated to some extent by high plant density. Both crops loosened the compacted field, the effect increased with an increase in plant density. Field beans decreased the soil bulk density up to 8 %, increased total porosity up to 8 % and air filled pores up to 19 % till 30 cm soil depth, the effects being higher than produced by soybeans.The increases in yields of wheat and barley and in their accumulated N were 9–57 % and 11–56 %, respectively after field bean and soybean as preceeding crops than after barley.
Inhaltsstoffe von Ackerbohnen und ihre Beeinflussung durch Genotyp und Umwelt
Authors: Keydel F. , Wünsch A. , Scheller H. 
Published: April 2008

AbstractUsing grain‐material of 12 field bean (Vicia faba) varieties from three quite different locations 10 different constituents and their range were examined and the following results obtained:

In the case of N‐, P‐, and K‐contents significant differences between the varieties and genotypes can be noticed. The average values obtained are 4.97, 0.63 and 1.33 % respectively.
Field beans have a relatively high Fe‐ and Zn‐content with an average of 61.1 respectively 40.1 ppm, whereas the average value of Mn and Cu was only 16.0 respectively 12.6 ppm.
As far as starch, crude fat and crude protein are concerned, great differences can be observed. The average values were 42.97, 1.83 and 31.06 %. However, significant differences were noticed between the varieties and the locations.
Assimilation and Partitioning of Photosynthate and Nitrogen in Isogenic Tall, Semidwarf, and Doubledwarf Winter Wheats
Authors: Kim N. I. , Paulsen G. M. 
Published: April 2008

AbstractPatterns of assimilation and partitioning of photosynthate and nitrogen in isogenic tall, semidwarf, and doubledwarf (Norin 10/5/Pawnee) ‘Pawnee’ hard red winter wheats (Triticum aestivum L.) were studied under controlled environmental conditions and field conditions. The objective of the investigations was to determine reasons for the advantageous harvest index associated with dwarf genes. Plants were sampled at four growth stages and separated into plant parts as they developed. Ribulose bisphosphate carboxylase (RuBPC) and nitrate reductase (NR) activities in leaves differed among growth stages but not among isogenic lines. Fructosan in sheaths, stems, and roots increased from the soft dough stage to maturity, but differed little among the lines. Nitrogen concentrations decreased in leaf blades, stems, and roots as plants developed to the soft dough stage and then stayed nearly constant until maturity. Nitrogen in all plant parts frequently varied directly with the complement of dwarfing genes, being lowest in the tall line and highest in the doubledwarf line. The tall and semidwarf lines had significantly higher grain yield, test weight, total dry matter, spike number, and 1000‐kernel weight than the doubledwarf line under either or both experimental conditions. The dwarf lines, however, had significantly higher kernel number per spike than the tall line. Harvest index was higher for the doubledwarf line (0.58) than for the two other lines (0.54).