bluuebunny/crossref_metadata_2025_split huggingface dataset:
Promiscuity in multidrug recognition and transport:  the bacterial MFS Mdr transporters
Authors: Lewinson Oded , Adler Julia , Sigal Nadejda , Bibi Eitan 
Published: June 2006

SummaryMultidrug (Mdr) transport is an obstacle to the successful treatment of cancer and infectious diseases, and it is mediated by Mdr transporters that recognize and export an unusually broad spectrum of chemically dissimilar toxic compounds. Therefore, in addition to its clinical significance, the Mdr transport phenomenon presents intriguing and challenging mechanistic queries. Recent studies of secondary Mdr transporters of the major facilitator superfamily (MFS) have revealed that they are promiscuous not only regarding their substrate recognition profile, but also with respect to matters of energy utilization, electrical and chemical flexibility in the Mdr recognition pocket, and surprisingly, also in their physiological functions.
The atypical amino‐terminal LPNTG‐containing domain of the pneumococcal human IgA1‐specific protease is required for proper enzyme localization and function
Authors: Bender Matthew H. , Weiser Jeffrey N. 
Published: June 2006

Summary Streptococcus pneumoniae produces a zinc metalloproteinase, Iga, which cleaves human immunoglobulin A1 (IgA1), and whose activity is predominantly localized to the bacterial surface. However, proper surface localization is not predicted using current models, as the LPNTG sorting motif is located atypically near the amino‐ rather than the carboxy‐terminus. The cell‐associated form of Iga was confirmed to be external to the bacterial membrane, and while bound tightly, its attachment to the cell wall is non‐covalent, but dependent on both a complete LPNTG sequence and sortase activity. Disruption of the region between the signal peptidase cleavage site and the LPNTG domain resulted in a localization defect, premature degradation, and an alteration of the ability of the enzyme to act on a monoclonal human IgA1 substrate and to enhance bacterial adherence, linking localization to enzyme function. Edman sequencing of cell‐associated Iga determined that the enzyme is processed at an unexpected site downstream of the sorting signal yet still associates with the bacterial surface. Our results indicate a non‐covalent re‐association between the carboxy‐terminal enzymatic domain and the cleaved, sorted amino‐terminal localization domain. This amino‐terminal motif is shared among the other zinc metalloproteinases in streptococci and suggests a novel conserved mechanism for the surface localization of protease activity.
The Zn(II)2Cys6 putative transcription factor NosA controls fruiting body formation in Aspergillus nidulans
Authors: Vienken Kay , Fischer Reinhard 
Published: June 2006

SummaryThe filamentous fungus Aspergillus nidulans reproduces asexually with conidiospores and sexually with ascospores, both of which are the result of complex morphogenetic pathways. The developmental decisions for both ways of reproduction largely depend on the action of stage‐specific transcription factors. Here we have characterized the putative Zn(II)2Cys6 transcription factor NosA (number of sexual spores), a protein of 675 aa, which shares 44% sequence identity to Pro1 from Sordaria macrospora and 43% identity to A. nidulans RosA, a second protein of that class. The nosA gene was constitutively expressed during the life cycle of A. nidulans and was upregulated during late asexual development and upon carbon starvation. The NosA protein localized to nuclei. Both, NosA and RosA, regulate sexual development. Whereas RosA plays a role in early decisions and represses sexual development, NosA activity is required for primordium maturation. Interestingly, the two factors are genetically linked, because RosA repressed NosA expression. This illustrates that the balance of these two Zn(II)2Cys6 proteins determines the fate of vegetative hyphae to undergo sexual development.
Acetyl phosphate‐sensitive regulation of flagellar biogenesis and capsular biosynthesis depends on the Rcs phosphorelay
Authors: Fredericks Christine E. , Shibata Satoshi , Aizawa Shin‐Ichi , Reimann Sylvia A. , Wolfe Alan J. 
Published: June 2006

SummaryAs part of our attempt to map the impact of acetyl phosphate (acetyl∼P) on the entire network of two‐component signal transduction pathways in Escherichia coli, we asked whether the influence of acetyl∼P on capsular biosynthesis and flagellar biogenesis depends on the Rcs phosphorelay. To do so, we performed a series of epistasis experiments: mutations in the components of the pathway that controls acetyl∼P levels were combined with mutations in components of the Rcs phosphorelay. Cells that did not synthesize acetyl∼P produced no capsule under normally permissive conditions, while those that accumulated acetyl∼P synthesized capsule under conditions previously considered to be non‐permissive. Acetyl∼P‐dependent capsular biosynthesis required both RcsB and RcsA, while the lack of RcsC restored capsular biosynthesis to acetyl∼P‐deficient cells. Similarly, acetyl∼P‐sensitive repression of flagellar biogenesis was suppressed by the loss of RcsB (but not of RcsA), while it was enhanced by the lack of RcsC. Taken together, these results show that both acetyl∼P‐sensitive activation of capsular biosynthesis and acetyl∼P‐sensitive repression of flagellar biogenesis require the Rcs phosphorelay. Moreover, they provide strong genetic support for the hypothesis that RcsC can function as either a kinase or a phosphatase dependent on environmental conditions. Finally, we learned that RcsB and RcsC inversely regulated the timing of flagellar biogenesis: rcsB mutants elaborated flagella prematurely, while rcsC mutants delayed their display of flagella. Temporal control of flagella biogenesis implicates the Rcs phosphorelay (and, by extension, acetyl∼P) in the transition of motile, planktonic individuals into sessile biofilm communities.
Aragonite cycles: diagenesis caught in the act
Authors: REUNING LARS , REIJMER JOHN J.G. , MATTIOLI EMANUELA 
Published: June 2006

AbstractOrganic biomarker and nannofossil assemblages are used in combination with sedimentary petrology to identify the role of diagenesis for the formation of a rhythmic calcareous succession. A record from the Early Pliocene of the Maldives (Ocean Drilling Program, ODP Leg 115) is presented containing precession and eccentricity cycles expressed as variable aragonite content. Additional sub‐Milankovitch cycles are caused by rhythmic precipitation of calcite cement in the lower part of the interval. Comparison with palaeo‐productivity indicators (nannofossils, chlorin, total organic carbon) suggests that cementation occurs preferentially in intervals characterized by increasing or decreasing productivity. The coupled variability in productivity and carbonate diagenesis is attributed to the effect of organic matter degradation in the sediment. The observed combination of primary and diagenetic factors hampers the interpretation of the cyclicity on Milankovitch and sub‐Milankovitch scales. Diagenetically stable proxies for palaeo‐productivity, such as nannofossil assemblage data, were used to distinguish between palaeoclimate and diagenetic influences.
Rapid increase in cuckoo egg matching in a recently parasitized reed warbler population
Authors: Avilés J. M. , Stokke B. G. , Moksnes A. , Røskaft E. , Åsmul M. , Møller A. P. 
Published: June 2006

Abstract
Parasitic cuckoos lay eggs that mimic those of their hosts, and such close phenotypic matching may arise from coevolutionary interactions between parasite and host. However, cuckoos may also explicitly choose hosts in a way that increases degree of matching between eggs of cuckoos and parasites, with female preference for specific host phenotypes increasing the degree of matching. We tested for temporal change in degree of matching between eggs of the parasitic European cuckoo (Cuculus canorus) and its reed warbler (Acrocephalus scirpaceus) host during 24 consecutive years in a recently parasitized reed warbler population. Cuckoo–host egg matching in an ultraviolet-brownness component yielding most of the chromatic variance of eggs improved during the study period. Improved matching was not due to changes in cuckoo egg phenotype. Cuckoo eggs matched host eggs for ultraviolet-brownness within nests irrespective of duration of sympatry. Ultraviolet-brownness of cuckoo eggs was similar to that of reed warbler eggs at parasitized nests, but differed from that of reed warbler eggs at unparasitized nests. These findings provide tentative support for the cuckoo preference hypothesis suggesting that cuckoo-host egg matching could partially be due to cuckoo females selecting host nests based on the appearance of their eggs.
Phenotypic plasticity in two marine snails: constraints superseding life history
Authors: Hollander J. , Collyer M. L. , Adams D. C. , Johannesson K. 
Published: June 2006

AbstractIn organisms encountering predictable environments, fixed development is expected, whereas in organisms that cannot predict their future environment, phenotypic plasticity would be optimal to increase local adaptation. To test this prediction we experimentally compared phenotypic plasticity in two rocky-shore snail species; Littorina saxatilis releasing miniature snails on the shore, and Littorina littorea releasing drifting larvae settling on various shores, expecting L. littorea to show more phenotypic plasticity than L. saxatilis. We compared magnitude and direction of vectors of phenotypic difference in juvenile shell traits after 3 months exposure to different stimuli simulating sheltered and crab-rich shores, or wave-exposed and crab-free shores. Both species showed similar direction and magnitude of vectors of phenotypic difference with minor differences only between ecotypes of the nondispersing species, indicating that plasticity is an evolving trait in L. saxatilis. The lack of a strong plastic response in L. littorea might be explained by limits rather than costs to plasticity.
Ultrastructural Morphometry of Mammary Gland in Transgenic and Non‐transgenic Rabbits
Authors: Dragin S. , Pivko J. , Massanyi P. , Lukac N. , Makarevich A. V. , Paleyanda R. K. , Chrenek P. 
Published: June 2006

SummaryThe mammary gland of transgenic animals has been used for the production of recombinant proteins of therapeutic and nutraceutical use. The objective of this study was to compare the ultrastructure of transgenic and non‐transgenic rabbit mammary gland tissue. New Zealand White transgenic rabbits were obtained by breeding non‐transgenic rabbits with transgenic founder rabbits containing a whey acidic protein‐human factor VIII (WAP‐hFVIII) transgene integrated into their genome. Samples of mammary gland tissue from lactating rabbit females were isolated by surgical procedures. These samples were examined by optical and electron microscopy and photographs were taken. Measurements of ultrastructural organelles were made from digital images of the mammary cells. No differences were found in the cellular structure of mammary tissue, but significant differences t(0.001) in the relative volume of mitochondria and vacuoles between transgenic and non‐transgenic mammary gland epithelium were observed.
Morphometrical Characteristics of Age‐Associated Changes in the Thymus of Old Male Wistar Rats
Authors: Plećaš‐Solarović B. , Pešić V. , Radojević K. , Leposavić G. 
Published: June 2006

SummaryIn order to provide a morphometrical description of the changes in the aged rat thymus and to relate them to apoptotic and proliferative activity of thymocytes, the thymuses from 3‐ and 18‐month‐old male Wistar rats and the percentages of bromodeoxyuridine‐incorporating and apoptotic cells in cultures of thymocytes were assessed by stereological analysis and flow cytometry, respectively. In old rats the volume of lymphoepithelial thymic tissue is markedly reduced, reflecting a sharp decrease in the total number of thymocytes. A reduction in the proliferative capacity of thymocytes and increase in their susceptibility to apoptosis are, most likely, primarily responsible for a 7‐fold reduction in thymic cellularity in old animals. Furthermore, only the volume of cortical compartment was affected by aging, while that of medulla, despite of reduced cellularity, was not significantly altered. The loss of functional tissue in aged thymus is compensated by a substantial increase in the volume of inter‐lobular connective and adipose tissue, so the thymic weight remained unaltered in old rats. These results suggest that thymus of aged Wistar rats exhibits morphological characteristics similar to those found in aged human thymus and thus may serve as an animal model for further investigations of thymus‐related changes in immunological aging.
Social Context Influences the Antipredator Behaviour of Fathead Minnows to Chemical Alarm Cues
Authors: Pollock M. S. , Pollock R. J. , Chivers D. P. 
Published: June 2006

AbstractPrey fishes, like many organisms under fluctuating predation threat, rely on multiple sources of information to accurately gauge current risk. This includes the use of chemical cues such as alarm cues from damaged conspecifics or familiar heterospecifics, as well as the odour of known predators. While each fish is well equipped with its own array of sensory abilities, they should also be alert to the behaviours of nearby neighbours who may have information they lack. In the present study, we tested the ability of fathead minnows to use social cues in combination with the odour of damaged conspecifics and heterospecifics to mediate the assessment of predation risk. Specifically, we tested whether the presence of a shoal of conspecifics or familiar heterospecifics would significantly change a minnow's antipredator behaviour when exposed to the odour of a damage‐release cue from a conspecific or ecologically similar heterospecific. The results of our study showed a significant interaction between the damage‐release cues to which the minnows were exposed and the presence/absence of shoalmates. These findings have important implications for the design of future investigations of antipredator responses because most studies of group‐living prey have been conducted on solitary subjects.
NO ARBITRAGE UNDER TRANSACTION COSTS, WITH FRACTIONAL BROWNIAN MOTION AND BEYOND
Authors: Guasoni Paolo 
Published: June 2006

We establish a simple no‐arbitrage criterion that reduces the absence of arbitrage opportunities under proportional transaction costs to the condition that the asset price process may move arbitrarily little over arbitrarily large time intervals.We show that this criterion is satisfied when the return process is either a strong Markov process with regular points, or a continuous process with full support on the space of continuous functions. In particular, we prove that proportional transaction costs of any positive size eliminate arbitrage opportunities from geometric fractional Brownian motion for H∈ (0, 1) and with an arbitrary continuous deterministic drift.
Influence of income and capital on reproduction in a viviparous snake: direct and indirect effects
Authors: Gregory P. T. 
Published: June 2006

AbstractA central issue in life‐history studies is the extent to which organisms are ‘capital’ versus ‘income’ breeders (i.e. using stored resources vs. current food intake). Snakes are primarily capital breeders, but income during vitellogenesis can also contribute to reproductive output. In Manitoba, the garter snake Thamnophis sirtalis has a short active season, with mating occurring upon emergence from hibernation and vitellogenesis shortly thereafter. Given the brevity of this sequence, animals in these populations should be almost exclusively capital breeders. Consistent with this prediction, in this experiment the reproductive output of recently mated snakes was influenced by mass of the mother at the time of mating but not by her food intake shortly after mating. Food eaten during pregnancy contributed significantly to postpartum mass but not to litter mass. However, the initial mass of snakes influenced both postpartum and litter mass. For snakes given a high ration of food, a female's relative mass (i.e. adjusted for body length) significantly influenced the actual amount she consumed (relatively lighter snakes ate more). Perhaps most important, among pregnant snakes, those that were initially relatively heavier gave birth substantially and significantly earlier. Thus, snakes that are relatively heavy when they mate may gain further fitness benefits following pregnancy (e.g. more time to acquire resources and for offspring to grow before winter), which can also be interpreted as indirect effects on reproduction. These life‐history variations may be relevant to population dynamics.
Personality traits in early phases of panic disorder: implications on the presence of agoraphobia, clinical severity and short‐term outcome
Authors: Carrera M. , Herrán A. , Ramírez M. L. , Ayestarán A. , Sierra‐Biddle D. , Hoyuela F. , Rodríguez‐Cabo B. , Vázquez‐Barquero J. L. 
Published: June 2006

Objective:  To explore the relations between personality traits using the Big Five model and presence of agoraphobia, clinical severity and short‐term outcome in an unbiased clinical sample of never‐treated panic disorder patients.Method:  Panic disorder (PD) patients (n = 103) in the first stages of their illness were evaluated using the Neuroticism‐Extraversion‐Openness Five Factor Inventory of Personality (NEO‐FFI) and were compared with a sample of healthy subjects. Severity was assessed by the Panic Disorder Severity Scale and the Clinical Global Impression Scales. Patients were evaluated after 8 weeks of naturalistic pharmacologic treatment with Selective Serotonin Reuptake Inhibitors.Results:  Panic disorder patients show more neuroticism than healthy subjects. Patients suffering from agoraphobia are more introverted than controls. Extraversion, in addition to gender and distress, during panic attacks allows to correctly classifying 72% of the cases of agoraphobia.Conclusion:  Low scores in extraversion contribute to explain the presence of agoraphobia in panic disorder. Personality traits are neither related to clinical severity nor to short‐term response to pharmacological treatment.
Early Complete Failures of Fixed Implant‐Supported Prostheses in the Edentulous Maxilla: A 3‐Year Analysis of 17 Consecutive Cluster Failure Patients
Authors: Jemt Torsten , Häger Per 
Published: June 2006

ABSTRACTBackground  Clusters of implant failures in the edentulous maxilla seem to occur in some patients. To create groups for analysis with higher numbers of these patients implies large original groups for inclusion.Purpose  The aim of this study was to retrospectively describe and compare a group of “cluster failure patients” with randomly selected patients treated in the edentulous maxilla.Materials and Methods  From a group of 1,267 consecutively treated patients in one clinic, all patients presenting failing fixed implant‐supported prostheses within the first 3 years of follow‐up were included. All patients were treated with turned titanium implants using two‐stage surgery. A control group of equal number of patients were created for comparison. Data on patients were retrospectively retrieved from their records, and compared.Results  Seventeen patients (1.3%) met the inclusion criteria in the entire group. The bone resorption index revealed less bone quantity in the study group (p < .05) during implant placement, but there was no difference regarding primary implant stability at first‐stage surgery. The distribution of short and long implants showed relatively higher number of short implants in the study group (p < .05), and more patients had a presurgical discussion on the risk of implant failure prior to treatment in this group (p < .05). Only 5 out of 102 implants (4.9%) were lost before prosthesis placement as compared to 38 and 25 lost implants during the following two years in the study group. Smoking habits and signs of bone loss related to periodontitis in the lower dentition were more frequent in the study group, but did not reach a significant level (p > .05).Conclusion  The results indicate that bone quantity, reflected in fixture length, has a significant impact on increased implant failure risk. Other factors of interest as predictors for implant failures could be smoking habits and also possibly signs of periodontitis in the opposing dentition.
Phytoplasma from little leaf disease affected sweetpotato in Western Australia: detection and phylogeny
Authors: Tairo F. , Jones R.A.C. , Valkonen J.P.T. 
Published: June 2006

AbstractSymptoms of leaf and stem chlorosis and plant stunting were common in sweetpotato plants (Ipomoea batatas) in farmers’ fields in two widely separated locations, Kununurra and Broome, in the tropical Kimberley region in the state of Western Australia in 2003 and 2004. In the glasshouse, progeny plants developed similar symptoms characteristic of phytoplasma infection, consisting of chlorosis and a stunted, bushy appearance as a result of proliferation of axillary shoots. The same symptoms were reproduced in the African sweetpotato cv. Tanzania grafted with scions from the plant Aus1 with symptoms and in which no viruses were detected. PCR amplification with phytoplasma‐specific primers and sequencing of the 16S‐23S rRNA gene region from two plants with symptoms, Aus1 (Broome) and Aus142A (Kununurra), revealed highly identical sequences. Phylogenetic analysis of the 16S rRNA gene sequences obtained from previously described sweetpotato phytoplasma and inclusion of other selected phytoplasma for comparison indicated that Aus1 and Aus142A belonged to the Candidatus Phytoplasma aurantifolia species (16SrII). The 16S genes of Aus1 and Aus142A were almost identical to those of sweet potato little leaf (SPLL‐V4) phytoplasma from Australia (99.3%–99.4%) but different from those of the sweetpotato phytoplasma from Taiwan (95.5%–95.6%) and Uganda (SPLL‐UG, 90.0%–90.1%). Phylogenetically, Aus1, Aus142A and a phytoplasma previously described from sweetpotato in the Northern Territory of Australia formed a group distinctly different from other isolates within Ca. Phytoplasma aurantifolia species. These findings indicate that novel isolates of the 16SrII‐type phytoplasma pose a potential threat to sustainable sweetpotato production in northern Australia.
Executioners, bystanders and victims: collective guilt, the legacy of denazification and the birth of twentieth-century transitional justice
Authors: O'Donnell Therese 
Published: June 2006

‘We did not go into the streets when our Jewish friends were led away; we did not scream until we too were destroyed … We are guilty of being alive.’Karl Jaspers The Question of German Guilt, p 66The following scene as recounted by the English writer James Stern occurred in a German town one week after Germany's unconditional surrender in May 1945. A crowd is gathered around a series of photographs which though initially seeming to depict garbage instead reveal dead human bodies. Each photograph has a heading ‘WHO IS GUILTY?’. The spectators are silent, appearing hypnotised, and eventually retreat one by one. The placards are later replaced with clearer photographs and placards proclaiming ‘THIS TOWNISGUILTY! YOUARE GUILTY!’.