bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion of trypsin to a functional threonine protease
Authors: Baird Teaster T. , Wright William D. , Craik Charles S. 
Published: May 2006

AbstractThe hydroxyl group of a serine residue at position 195 acts as a nucleophile in the catalytic mechanism of the serine proteases. However, the chemically similar residue, threonine, is rarely used in similar functional context. Our structural modeling suggests that the Ser 195 → Thr trypsin variant is inactive due to negative steric interaction between the methyl group on the β‐carbon of Thr 195 and the disulfide bridge formed by cysteines 42 and 58. By simultaneously truncating residues 42 and 58 and substituting Ser 195 with threonine, we have successfully converted the classic serine protease trypsin to a functional threonine protease. Substitution of residue 42 with alanine and residue 58 with alanine or valine in the presence of threonine 195 results in trypsin variants that are 102–104‐fold less active than wild type in kcat/KM but >106‐fold more active than the Ser 195 → Thr single variant. The substitutions do not alter the substrate specificity of the enzyme in the P1′– P4′ positions. Removal of the disulfide bridge decreases the overall thermostability of the enzyme, but it is partially rescued by the presence of threonine at position 195.
Socio‐environmental influences on adolescents’ alcohol outcome expectancies: a prospective analysis
Authors: Martino Steven C. , Collins Rebecca L. , Ellickson Phyllis L. , Schell Terry L. , McCaffrey Daniel 
Published: May 2006

ABSTRACTAims  To investigate the prospective influence of social influence and social bonding variables on the development of alcohol outcome expectancies among adolescents with and without drinking experience.Design  Longitudinal data from students in the control schools of a field trial designed to evaluate a school‐based drug prevention program.Setting  A total of 19 middle schools in South Dakota, USA.Measurements  An alcohol outcome expectancy scale administered to 1410 students in grades 8 and 9. After using confirmatory factor analysis (CFA) to develop an expectancies measure, multiple‐group (grade 8 drinkers versus grade 8 non‐drinkers) path analysis was used to model 9th grade alcohol expectancies. Grade 8 social influence and bonding variables were used as predictors, controlling for grade 8 expectancies.Findings  At the bivariate level, peer and adult influences and social bonding variables were related consistently to alcohol outcome expectancies among drinkers and non‐drinkers. A bivariate relationship between alcohol advertising and alcohol expectancies was found among drinkers only. In the multivariate model, greater alcohol use by important adults predicted independently increased alcohol positivity among drinkers; greater perceived approval of alcohol use by parents and peers predicted diminished perceived potency of alcohol among non‐drinkers. Advertisement exposure and social bonding variables were not independent predictors of alcohol expectancies in the multivariate model.Conclusions  These findings suggest that attempts to alter adolescents’ alcohol expectancies are likely to fail unless they address the influence of immediate social models on these beliefs.
Phenology of a northern hardwood forest canopy
Authors: RICHARDSON ANDREW D. , BAILEY AMEY SCHENCK , DENNY ELLEN G. , MARTIN C. WAYNE , O'KEEFE JOHN 
Published: May 2006

AbstractWhile commonplace in other parts of the world, long‐term and ongoing observations of the phenology of native tree species are rare in North America. We use 14 years of field survey data from the Hubbard Brook Experimental Forest to fit simple models of canopy phenology for three northern hardwood species, sugar maple (Acer saccharum), American beech (Fagus grandifolia), and yellow birch (Betula alleghaniensis). These models are then run with historical meteorological data to investigate potential climate change effects on phenology. Development and senescence are quantified using an index that ranges from 0 (dormant, no leaves) to 4 (full, green canopy). Sugar maple is the first species to leaf out in the spring, whereas American beech is the last species to drop its leaves in the fall. Across an elevational range from 250 to 825 m ASL, the onset of spring is delayed by 2.7±0.4 days for every 100 m increase in elevation, which is in reasonable agreement with Hopkin's law. More than 90% of the variation in spring canopy development, and just slightly less than 90% of the variation in autumn canopy senescence, is accounted for by a logistic model based on accumulated degree‐days. However, degree‐day based models fit to Hubbard Brook data appear to overestimate the rate at which spring development occurs at the more southerly Harvard Forest. Autumn senescence at the Harvard Forest can be predicted with reasonable accuracy in sugar maple but not American beech. Retrospective modeling using five decades (1957–2004) of Hubbard Brook daily mean temperature data suggests significant trends (P≤0.05) towards an earlier spring (e.g. sugar maple, rate of change=0.18 days earlier/yr), consistent with other studies documenting measurable climate change effects on the onset of spring in both North America and Europe. Our results also suggest that green canopy duration has increased by about 10 days (e.g. sugar maple, rate of change=0.21 days longer/yr) over the period of study.
A B‐lectin receptor kinase gene conferring rice blast resistance
Authors: Chen Xuewei , Shang Junjun , Chen Dexi , Lei Cailin , Zou Yan , Zhai Wenxue , Liu Guozhen , Xu Jichen , Ling Zhongzhuan , Cao Gang , Ma Bingtian , Wang Yuping , Zhao Xianfeng , Li Shigui , Zhu Lihuang 
Published: May 2006

SummaryRice blast, caused by the fungal pathogen Magnaporthe grisea, is one of the most devastating diseases in rice worldwide. The dominant resistance gene, Pi‐d2 [previously named Pi‐d(t)2], present in the rice variety Digu, confers gene‐for‐gene resistance to the Chinese blast strain, ZB15. Pi‐d2 was previously mapped close to the centromere of chromosome 6. In this study, the Pi‐d2 gene was isolated by a map‐based cloning strategy. Pi‐d2 encodes a receptor‐like kinase protein with a predicted extracellular domain of a bulb‐type mannose specific binding lectin (B‐lectin) and an intracellular serine–threonine kinase domain. Pi‐d2 is a single‐copy gene that is constitutively expressed in the rice variety Digu. Transgenic plants carrying the Pi‐d2 transgene confer race‐specific resistance to the M. grisea strain, ZB15. The Pi‐d2 protein is plasma membrane localized. A single amino acid difference at position 441 of Pi‐d2 distinguishes resistant and susceptible alleles of rice blast resistance gene Pi‐d2. Because of its novel extracellular domain, Pi‐d2 represents a new class of plant resistance genes.
Histological and genotypical characterization of feline cutaneous mycobacteriosis: a retrospective study of formalin‐fixed paraffin‐embedded tissues
Authors: Davies Jennifer L. , Sibley Jennifer A. , Myers Sherry , Clark Edward G. , Appleyard Greg D. 
Published: May 2006

AbstractTwenty‐nine cases presumptively diagnosed as feline cutaneous mycobacteriosis were evaluated microscopically with haematoxylin and eosin and modified Fite's stained sections using archived formalin‐fixed paraffin‐embedded tissue specimens. Lesions were characterized histologically as feline leprosy (7 cases lepromatous and 16 cases tuberculoid) or atypical mycobacteriosis (3 cases); three cases did not fit these criteria and were classified as ‘miscellaneous’. Actinomycetales‐specific polymerase chain reaction (PCR) of variable regions 1, 2 and 3 of the 16S ribosomal RNA (rRNA) gene and subsequent sequence analysis of the amplicons were performed to identify the species of mycobacteria associated with each case. Together, this study identified 10 different Actinomycetales organisms with greater than 98% nucleotide sequence identity to named species, nine were of the genus Mycobacterium and eight were associated with feline leprosy (both lepromatous and tuberculoid). Based on this study, we conclude that feline cutaneous mycobacteriosis should be considered as a syndrome with varied clinical and histological presentations associated with a variety of different Mycobacterium species, organisms other than Mycobacterium sp. may be associated with feline cutaneous mycobacteriosis lesions, and molecular diagnostic techniques can be an important tool for identifying agents associated with lesions of feline cutaneous mycobacteriosis.
Otoscopic, cytological, and microbiological examination of the equine external ear canal
Authors: Sargent Sandra J. , Frank Linda A. , Buchanan Benjamin R. , Donnell Robert L. , Morandi Federica 
Published: May 2006

AbstractOtoscopic examination and cytology of the equine ear would be beneficial in diseases such as head trauma, headshaking, otitis externa secondary to otitis media, vestibular disease, aural neoplasia and aural pruritus secondary to parasites. In practice, otic examinations of horses are rarely done due to the perceived difficulty in visualizing the equine external ear canal and tympanic membrane, as well as the need for chemical restraint. In this study, the proximal external ear canal was examined in live horses using a handheld otoscope and in cadaver heads using video otoscopy. Visualization of the proximal ear canal of the sedated horse could be done with a handheld otoscope, but more sedation or general anaesthesia and a video otoscope would be required to adequately visualize the tympanic membrane in the live horse. The proximal ear canals of 18 horses were examined cytologically and cultured aerobically. In three horses, both ears were sampled. No cells or organisms were seen on cytological examination of 11/21 ears. Nine of the 21 ears were sterile when cultured. Ten of the 21 ears had mixed growth with low numbers of organisms (Corynebacteriumsp. being most common). Two of the 21 ears had heavy growth of a single organism (Corynebacteriumsp. andStaphylococcus intermedius, respectively). Equine cadaver heads were examined in cross‐section by computed tomography (CT) imaging and histopathology in order to further understand the anatomy of the equine external ear canal. Equine practitioners should be aware that otic examination is possible and may provide important diagnostic information.
A randomized comparative clinical trial of recombinant canine interferon‐γ (KT‐100) in atopic dogs using antihistamine as control
Authors: Iwasaki Toshiroh , Hasegawa Atsuhiko 
Published: May 2006

AbstractRecombinant canine interferon‐γ (KT‐100) or topical antihistamine (diphenhydramine: DH) was administered to dogs with atopic dermatitis (AD) for 4 weeks and their efficacies were compared using pruritus, excoriation, erythema and alopecia as evaluation criteria. Clinical studies on 92 atopic dogs (KT‐100 group: 63, DH group: 29) were conducted at 18 animal hospitals in Japan. KT‐100 was administered subcutaneously once a day three times a week on alternating days for 4 weeks. DH was administered topically twice daily for 4 weeks. The efficacy rates of the KT‐100 group on day 28 were 72.1% for pruritus, 73.8% for excoriation, 75.4% for erythema and 60.7% for alopecia, which were significantly higher than those of the DH group (20.7% for pruritus, 27.6% for excoriation, 24.1% for erythema and 24.1% for alopecia).
Specific activity of cell‐surface acid phosphatase in different bacterioplankton morphotypes in an acidified mountain lake
Authors: Nedoma Jir̆í , Vrba Jaroslav 
Published: May 2006

SummaryActivity of extracellular acid phosphatases was measured at single‐cell level in bacterioplankton groups defined by their morphology and size, in acidified mountain Lake C̆ertovo, during the 2003 season, with a method based on use of the substrate ELF97 phosphate which provides fluorescent precipitates upon hydrolysis by phosphatases. The bacterial cell‐associated precipitates were quantified by image analysis. A specific, conspicuous, apparently homogeneous morphotype of curved cells of ∼5 µm average length, despite its low total biomass (average of 4%), contributed significantly (in average by 31%) to the total bacterioplankton phosphatase activity in Lake C̆ertovo (ranging from 1.0 to 12.7 µmol l−1 h−1, using ELF97 phosphate as a substrate). Bacterial filaments (> 10 µm), although comprising in average 85% of bacterioplankton biomass, contributed to the total bacterioplankton activity only by 45%. Biomass‐specific activity of extracellular (cell‐surface) phosphatases of the main bacterioplankton morphotypes increased in the order filaments < cocci and rods < curved cells. The biomass‐specific activity of bacterioplankton extracellular phosphatases (0–300 nmol µgC−1 h−1) was generally highest in the spring and decreased gradually during summer. These changes could result from seasonal changes in the phosphorus status of the lake and from subsequent regulation of enzyme expression by bacteria.
Characterization of outer membrane vesicles released by the psychrotolerant bacterium Pseudoalteromonas antarctica NF3
Authors: Nevot Maria , Deroncelé Víctor , Messner Paul , Guinea Jesús , Mercadé Elena 
Published: May 2006

Summary Pseudoalteromonas antarctica NF3 is an Antarctic psychrotolerant Gram‐negative bacterium that accumulates large amounts of an extracellular polymeric substance (EPS) with high protein content. Transmission electron microscopy analysis after high‐pressure freezing and freeze substitution (HPF‐FS) shows that the EPS is composed of a capsular polymer and large numbers of outer membrane vesicles (OMVs). These vesicles are bilayered structures and predominantly spherical in shape, with an average diameter of 25–70 nm, which is similar to what has been observed in OMVs from other Gram‐negative bacteria. Analyses of lipopolysaccharide (LPS), phospholipids and protein profiles of OMVs are consistent with the bacterial outer membrane origin of these vesicles. In an initial attempt to elucidate the functions of OMVs proteins, we conducted a proteomic analysis on 1D SDS‐PAGE bands. Those proteins putatively identified match with outer membrane proteins and proteins related to nutrient processing and transport in Gram‐negative bacteria. This approach suggests that OMVs present in the EPS from P. antarctica NF3, might function to deliver proteins to the external media, and therefore play an important role in the survival of the bacterium in the extreme Antarctic environment.
HOW DO BUILDINGS MEAN? SOME ISSUES OF INTERPRETATION IN THE HISTORY OF ARCHITECTURE1
Authors: WHYTE WILLIAM 
Published: May 2006

Architectural history as we know it has been written tacitly adhering to the crudest version of the paradigm of communication: all the attention has been focussed on the design of the new forms, none on their interpretation. It is time to realize, that even within the limits of the paradigm of communication, there should be a history of meaning, not only a history of forms.2—Juan Pablo Bonta
You think philosophy is difficult enough, but I can tell you it is nothing to the difficulty of being a good architect.3—Ludwig Wittgenstein
ABSTRACTDespite growing interest from historians in the built environment, the use of architecture as evidence remains remarkably under‐theorized. Where this issue has been discussed, the interpretation of buildings has often been likened to the process of reading, in which architecture can be understood by analogy to language: either as a code capable of use in communicating the architect's intentions or more literally as a spoken or written language in its own right. After a historiographical survey, this essay, by contrast, proposes that the appropriate metaphor is one of translation. More particularly, it draws on the work of Mikhail Bakhtin to suggest that architecture—and the interpretation of architecture— comprises a series of transpositions. As a building is planned, built, inhabited, and interpreted, so its meaning changes. The underlying logic of each medium shapes the way in which its message is created and understood. This suggests that the proper role of the historian is to trace these transpositions. Buildings, then, can be used as a historical source, but only if the historian takes account of the particular problems that they present. In short, architecture should not be studied for its meaning, but for its meanings. As historians we are always translating architecture: not reading its message, but exploring its multiple transpositions.
Activity patterns of brown bears (Ursus arctos) in Slovenia and Croatia
Authors: Kaczensky P. , Huber D. , Knauer F. , Roth H. , Wagner A. , Kusak J. 
Published: May 2006

AbstractIn most of Europe, true wilderness areas do not exist and brown bears Ursus arctos generally have to cope with human disturbance and infrastructure. The few studies in Europe that have investigated brown bear activity have demonstrated a predominantly nocturnal and ‘shy’ behaviour in bears. There is still quite a debate on whether the shy, nocturnal bears of Europe are the result of centuries of persecution by men (genetically fixed trait) or whether hunting and the high disturbance potential in the multi‐use landscapes are the driving force (individually learnt trait). We analysed the activity pattern of 16 individual bears monitored for 3372 h between May and October 1982–1998 in the Dinaric Mountains of Slovenia and Croatia. The data were collected via time sampling and basically analysed using two approaches: a general linear model with seasonal component to delineate the most important variables influencing the activity pattern and level and cluster analysis to group bears according to their 24‐h activity pattern. Time of day and age were the most important variables predicting activity. Although individual variation in the activity pattern was high among individual bears, in general, yearlings were more diurnal and had a less distinct difference between day‐ and night‐time activity levels than adult bears. Subadults were somewhat intermediate to adults and yearlings. We believe that nocturnal behaviour is most likely driven through negative experiences with humans, giving space for much individual variation. More research is needed to prove the causal relationship of nocturnal behaviour and the degree of disturbance that an individual bear is exposed to.
Abstract no.: 1 Statins and oxysterol‐induced vascular smooth muscle cell death
Authors: Schrijvers D. , Fret H. , Martinet W. , Bult H. 
Published: May 2006

Objective  The strength of the fibrous cap of an atherosclerotic plaque is maintained by smooth muscle cells (SMCs). 7‐Ketocholesterol (7‐KC), and other oxysterols formed inside plaques, are known to induce SMC death, thereby increasing the risk of rupture and myocardial infarction (MI). Statins are known to protect patients from MI, but paradoxically they induce apoptosis in vascular SMCs as well. The aim of this study was to investigate the cell death effects of statins in 7‐KC‐treated SMCs.Methods  Rabbit aorta SMCs (50 000; passage 2–6) were seeded in 24 well plates in HAM F10 with 10% foetal bovine serum (FBS). The next day, they were exposed to 25 μM 7‐KC and 10−8–10−4 M of fluvastatin (fluva), simvastatin (simva) or pravastatin (prava) in the presence of 2% FBS. Uptake of neutral red (0.01%, added 16 h later) was measured for 2 h as viability index.Results  SMC viability decreased from 100% to 55 ± 3% (n = 28) upon 18 h exposure to 25 μM 7‐KC. High concentrations of fluva (≥ 10 μM) or simva (≥ 1 μM) also induced a concentration‐dependent loss of SMC viability; prava was always without effect. Interestingly, fluva and simva partly reversed the viability loss evoked by 7‐KC. Similar effects were seen when mitochondrial function was assessed using the succinate dehydrogenase substrate MTT. Fluva and simva alone were without effect, but they attenuated the mitochondrial dysfunction induced by 7‐KC. In contrast, both statins and 7‐KC enhanced the conversion of the caspase substrate DEVD‐R110 by SMC monolayers.Conclusions  The results confirm that 7‐KC and high concentrations of lipophilic statins induce SMC death and activate caspases. Yet, in 7‐KC treated SMCs statins paradoxically attenuated viability loss and mitochondrial dysfunction. This clearly illustrates that drug effects seen in normal SMCs are not necessarily predictive of their action in an atherosclerotic setting.
Abstract no.: 3 Vitreous– a barrier to non‐viral ocular gene therapy
Authors: Peeters L. , Sanders N.N. , Braeckmans K. , Boussery K. , Van de Voorde J. , De Smedt S. C. , Demeester J. 
Published: May 2006

Purpose  Intravitreal injection of therapeutic DNA, complexed to non‐viral carriers like cationic liposomes, may be promising to treat many severe retinal eye diseases. However, after intravitreal injection such DNA/cationic liposome complexes, so called lipoplexes, which are typically some hundreds of nanometers in size, must first diffuse through the vitreous before they can reach the retina. The aim of this study was both to elucidate whether vitreous is a barrier for the lipoplexes as well as to evaluate strategies to overcome this barrier.Methods  Fluorescent polystyrene nanospheres and lipoplexes were mixed with vitreous and their mobility was monitored by fluorescence recovery after photobleaching (FRAP), a microscopy based technique. The stability of lipoplexes and naked pDNA in vitreous was studied by gel electrophoresis.Results  We showed that polystyrene nanospheres, in our first experiments used as a model for the lipoplexes, do not diffuse freely into the vitreous but adhere to fibrillar structures in the vitreous, most likely to collagen fibers. Making the surface of the polystyrene nanospheres hydrophillic by attaching hydrophillic polyethyleneglycol (PEG) chains at their surface circumvented the binding to fibrillar structures in the vitreous. FRAP revealed that ‘pegylated’ polystyrene nanospheres, as long as they are smaller than 500 nm in size, are indeed mobile in the vitreous. It was further demonstrated that lipoplexes severely aggregate in vitreous and strongly bind to biopolymers in the vitreous which immobilizes them completely. However, as observed for the polystyrene nanospheres, coating of the lipoplexes with PEG avoided both their aggregation in the vitreous as well as their binding to fibrillar structures.Conclusions  Modifying the surface of lipoplexes with hydrophylic PEG chains prevents them from aggregation in vitreous. In this way lipoplexes are obtained which can freely move in vitreous, an absolute request to be able to reach the retina after intravitreal injection.