bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chaperone‐like activity and hydrophobicity of α‐crystallin
Authors: Reddy G. Bhanuprakash , Kumar P. Anil , Kumar M. Satish 
Published: November 2006

Abstractα‐Crystallin, a prominent member of small heat shock protein (sHsp) family and a major structural protein of the eye lens is a large polydisperse oligomer of two isoforms, αA‐ and αB‐crystallins. Numerous studies have demonstrated that α‐crystallin functions like a molecular chaperone in preventing the aggregation of various proteins under a wide range of stress conditions. The molecular chaperone function of α‐crystallin is thus considered to be vital in the maintenance of lens transparency and in cataract prevention. α‐Crystallin selectively interacts with non‐native proteins thereby preventing them from aggregation and helps maintain them in a folding competent state. It has been proposed and generally accepted that α‐crystallin suppresses the aggregation of other proteins through the interaction between hydrophobic patches on its surface and exposed hydrophobic sites of partially unfolded substrate protein. However, a quantifiable relationship between hydrophobicity and chaperone‐like activity remains a matter to be concerned about. On an attentive review of studies on α‐crystallin chaperone‐like activity, particularly the studies that have direct or indirect implications to hydrophobicity and chaperone‐like activity, we found several instances wherein the correlation between hydrophobicity and its chaperone‐like activity is paradoxical. We thus attempted to provide an overview on the role of hydrophobicity in chaperone‐like activity of α‐crystallin, the kind of evaluation done for the first time.
iubmb Life, 58: 632 ‐ 641, 2006
Influence of a brushing working motion on the fatigue life of NiTi rotary instruments
Authors: Plotino G. , Grande N. M. , Sorci E. , Malagnino V. A. , Somma F. 
Published: November 2006

AbstractAim  To evaluate the cyclic fatigue resistance of Mtwo NiTi rotary instruments when used with a brushing or no‐brushing action in oval root canals.Methodology  Cyclic fatigue testing of instruments was performed in tapered artificial canals with a 5 mm radius of curvature and an angle of curvature of 60°. Twenty Mtwo instruments for each size were selected and divided into two groups: group A = 10 instruments used with a no‐brushing motion (control group); group B = 10 instruments used with a brushing‐milling action. Each Mtwo instrument was used for cleaning and shaping 10 oval root canals. In all 80 instruments were rotated until fracture occurred and the number of cycles to failure (NCF) recorded. Data were analysed by one‐way anova, Tukey HSD test and independent sample t‐test to determine any statistical difference; the significance was determined at the 95% confidence level.Results  No statistically significant reduction of NCF between instruments used with a no‐brushing motion (group A) and instruments used with a brushing motion (group B) were apparent except for size 25, 0.06 taper. Mtwo size 10, 0.04 taper, size 15, 0.05 taper, size 20, 0.06 taper, size 25, 0.06 taper instruments had a decrease in life span of 1%, 0.5%, 8% and 19%, respectively.Conclusions  Fatigue life of instruments of larger size could be reduced by using them with a lateral brushing or pressing movement. However, each file was successfully operated without intracanal failure, demonstrating that Mtwo rotary instruments can be used safely in a brushing action in simulated clinical conditions up to 10 times in oval canals.
In vivo comparison of working length determination with two electronic apex locators
Authors: Wrbas K. T. , Ziegler A. A. , Altenburger M. J. , Schirrmeister J. F. 
Published: November 2006

AbstractAim  To compare the accuracy of two electronic apex locators (EALs) in the same teeth in vivo.Methodology  The working lengths in 20 teeth with a single canal were determined with two different EALs (Root ZX; J. Morita Corporation, Tokyo, Japan and Raypex® 5 VDW, Munich, Germany) before extraction. When the first EAL was used the files were advanced until the display indicated the ‘apical constriction’. The files were then fixed in removable and replaceable light curing composite patterns. The procedure was repeated in the same tooth with the second EAL and a different file. The teeth were then extracted and the apical 4 mm of the root canals were exposed. After that the apical parts with the repositioned files in the canals were digitally photographed under a light microscope. On the images the minor diameter and the major foramen of each sample were marked and the respective distances of the file tips from these positions were measured with a computer program. Subsequently the values of the two groups of EALs were compared using a paired sample t‐test.Results  The minor foramen was located within the limits of ±0.5 mm in 75% of the cases with the Root ZX and in 80% of the cases with Raypex® 5. The paired sample t‐test showed no significant difference between the EALs regarding determination of the minor foramen.Conclusion  The use of EALs is a reliable method for determining working length. The differences between the two EALs were not statistically significant.
Experimental tests of the role of predation in the population dynamics of voles and lemmings
Authors: SUNDELL JANNE 
Published: November 2006

ABSTRACT

Reasons for fluctuating populations of small mammals have been intensively investigated since the early days of modern ecology. Particular interest has been taken in vole populations exhibiting multiannual oscillations. Much empirical and theoretical work has been accomplished to find out the key factor(s) driving these population cycles and many reviews have been written about the results.
One of the most plausible processes for explaining regular fluctuations in small mammals is predation. Here I review the existing literature on the experimental studies of the role of predation in vole population dynamics in the hope that a critical examination of these studies will help researchers improve the design of future experiments.
Most predation manipulations have been done in exclosures, but there are also studies that have attempted to reduce or increase predator numbers in non‐fenced areas, islands and enclosures.
As the number of experimental studies has increased, their quality in terms of replication, use of controls and realistic spatial and temporal scales has also improved.
Most studies have found population‐level effects of predator manipulations on prey populations. The effects have varied from very weak to very strong, reflecting dissimilar experimental designs and the great variety of predator–prey interactions among different kinds of species in different landscapes. Most of these studies show that predation limits population growth of voles, and in some circumstances even regulate vole population fluctuations, but none of them clearly demonstrates that predation consistently changes fluctuation patterns of voles.
To be able to assess more reliably the true role of predation on (cyclic) population fluctuations of voles, more competent experiments are still needed not only over the geographical range of cyclic population dynamics, but also in areas of weakly or non‐cyclic populations of voles.
Assessing the taxonomic status of dingoes Canis familiaris dingo for conservation
Authors: ELLEDGE AMANDA E. , LEUNG LUKE K.‐P. , ALLEN LEE R. , FIRESTONE KAREN , WILTON ALAN N. 
Published: November 2006

ABSTRACT

The conservation status of the dingo Canis familiaris dingo is threatened by hybridization with the domestic dog C. familiaris familiaris. A practical method that can estimate the different levels of hybridization in the field is urgently required so that animals below a specific threshold of dingo ancestry (e.g. 1/4 or 1/2 dingoes) can reliably be identified and removed from dingo populations.
Skull morphology has been traditionally used to assess dingo purity, but this method does not discriminate between the different levels of dingo ancestry in hybrids. Furthermore, measurements can only be reliably taken from the skulls of dead animals.
Methods based on the analysis of variation in DNA are able to discriminate between the different levels of hybridization, but the validity of this method has been questioned because the materials currently used as a reference for dingoes are from captive animals of unproven genetic purity. The use of pre‐European materials would improve the accuracy of this method, but suitable material has not been found in sufficient quantity to develop a reliable reference population. Furthermore, current methods based on DNA are impractical for the field‐based discrimination of hybrids because samples require laboratory analysis.
Coat colour has also been used to estimate the extent of hybridization and is possibly the most practical method to apply in the field. However, this method may not be as powerful as genetic or morphological analyses because some hybrids (e.g. Australian cattle dog × dingo) are similar to dingoes in coat colour and body form. This problem may be alleviated by using additional visual characteristics such as the presence/absence of ticking and white markings.
Novel DNA binding protein SarZ contributes to virulence in Staphylococcus aureus
Authors: Kaito Chikara , Morishita Daisuke , Matsumoto Yasuhiko , Kurokawa Kenji , Sekimizu Kazuhisa 
Published: November 2006

SummaryWe previously reported that the cvfA gene is a virulence regulatory gene in Staphylococcus aureus. Here, we identified a novel gene named sarZ that acts as a multicopy suppressor of decreased haemolysin production in the cvfA deletion mutant. The amount of sarZ transcripts was decreased in the cvfA mutant. The sarZ‐deletion mutant produced less haemolysin and attenuated virulence in a silkworm‐infection model and a mouse‐infection model. The amino acid sequence of the sarZ gene product had 19% identity with the transcription factor MarR in Escherichia coli, and the internal region contained a winged helix–turn–helix motif (wHTH), a known DNA binding domain. Purified recombinant SarZ protein had binding affinity for the promoter region of the hla gene that encodes α‐haemolysin. SarZ mutant proteins with an amino acid substitution in the N‐terminal region or in the wHTH motif had significantly decreased DNA binding. The mutated sarZ genes encoding SarZ mutant proteins with a low affinity for DNA did not complement the decreased haemolysin production or the attenuated killing ability against silkworms in the sarZ mutant. These results suggest that the DNA binding activity of the SarZ protein is required for virulence in S. aureus.
Control of fatty acid desaturation: a mechanism conserved from bacteria to humans
Authors: Aguilar Pablo S. , De Mendoza Diego 
Published: November 2006

SummaryUnsaturated fatty acids (UFAs) have profound effects on the fluidity and function of biological membranes. Microorganisms, plants and animals regulate the synthesis of UFAs during changing environmental conditions as well as in response to nutrients. UFAs homeostasis in many organisms is achieved by feedback regulation of fatty acid desaturase gene transcription through signalling pathways that are governed by sensors embedded in cellular membranes. Here, we review recently discovered components of the regulatory machinery governing the transcription of fatty acid desaturases in bacteria, yeasts and animals that indicate an ancient role of transmembrane signalling mechanisms and integrate membrane composition with lipid biosynthesis.
Apoptosis in yeast – mechanisms and benefits to a unicellular organism
Authors: Gourlay Campbell W. , Du Wei , Ayscough Kathryn R. 
Published: November 2006

SummaryInitial observations that the budding yeast Saccharomyces cerevisiae can be induced to undergo a form of cell death exhibiting typical markers of apoptosis has led to the emergence of a thriving new field of research. Since this discovery, a number of conserved pro‐ and antiapoptotic proteins have been identified in yeast. Indeed, early experiments have successfully validated yeasts as a powerful genetic tool with which to investigate mechanisms of apoptosis. However, we still have little understanding as to why programmes of cell suicide exist in unicellular organisms and how they may be benefit such organisms. Recent research has begun to elucidate pathways that regulate yeast apoptosis in response to environmental stimuli. These reports strengthen the idea that physiologically relevant mechanisms of programmed cell death are present, and that these function as important regulators of yeast cell populations.
Distinct roles of electric and hydraulic signals on the reaction of leaf gas exchange upon re‐irrigation in Zea mays L.
Authors: GRAMS THORSTEN E. E. , KOZIOLEK CHRISTIANE , LAUTNER SILKE , MATYSSEK RAINER , FROMM JÖRG 
Published: November 2006

ABSTRACTThe hypothesis that electric and hydraulic long‐distance signals modify photosynthesis and stomatal aperture upon re‐irrigation in intact drought‐stressed plants was examined. Maize plants (Zea mays L.) were exposed to drought conditions by decreasing the soil water content to 40–50% of field capacity. The decrease in water content resulted in a decline in stomatal conductance to 50–60% of the level in well‐watered plants. Re‐irrigation of the plants initiated both hydraulic and electric signals, followed by a two‐phase response of the net CO2 uptake rate and stomatal conductance of leaves. The transitional first phase (phase 1) is characterized by a rapid decrease in both levels. In the second phase (phase 2), both parameters gradually increase to levels above those of drought‐stressed plants. Elimination of either the hydraulic signal by compensatory pressure application to the root system, or of the electric signal by cooling of the leaf blade gave evidence that the two signals (1) propagated independently from each other and (2) triggered the two‐phase response in leaf gas exchange. The results provided evidence that the hydraulic signal initiated a hydropassive decrease in stomatal aperture and for the involvement of electric signals in the regulation of photosynthesis of drought‐stressed plants.
An overview on congenital alopecia in domestic animals
Authors: Mecklenburg Lars 
Published: November 2006

AbstractAlopecia, that is, lack of hair in any quantity, is a frequent complaint of pet owners. Although mostly acquired, rare congenital forms of alopecia exist that are associated with abnormalities in hair follicle morphogenesis. Congenital alopecias can result in changes in quality or quantity of hair follicles and the hair fibres produced by them. They vary in terms of clinical presentation and mode of inheritance. Histopathology is usually needed in order to differentiate between a reduced number of otherwise normal hair follicles and qualitative hair follicle abnormalities. Although our understanding of the molecular mechanisms that drive hair follicle morphogenesis in mice and humans has significantly increased during the last decade, still very little is known about congenital alopecias in domestic animals. Because of their rarity and the general lack of knowledge about their pathophysiology, classification of congenital alopecias in domestic animals is still unsatisfactory.This article reviews hair follicle morphogenesis and its most important molecular mechanisms, and it discusses the various forms of congenital alopecia occurring in domestic animals that have been described in the literature, differentiating between hair follicle aplasia, hair follicle dysplasia (i.e. defects associated with hair follicle development and defects associated with hair shaft formation), and neuroectodermal dysplasias, the latter involving the hair follicle pigmentary system.
Evaluation of a serological test (indirect ELISA) for the diagnosis of sarcoptic mange in red foxes (Vulpes vulpes)
Authors: Bornstein Set , Frössling Jenny , Näslund Katarina , Zakrisson Göran , Mörner Torsten 
Published: November 2006

AbstractSarcoptic mange occurs in many parts of the world and is common in populations of domestic and wild canids, including red foxes (Vulpes vulpes). In recent years, an indirect antibody enzyme‐linked immunosorbent assay (ELISA), with higher sensitivity and specificity than traditional diagnostic methods, has been successfully applied in the diagnosis of sarcoptic mange in dogs. The same ELISA has also demonstrated specific antibodies toSarcoptes scabieiin experimentally infected red foxes. The aim of this study was to evaluate the indirect ELISA when used to detect antibodies toS. scabieiin field sera from Swedish red foxes. One cohort of both infected and non‐infected red foxes (cohort 1;n = 88), and one cohort of apparently non‐infected foxes (cohort 2;n = 67) were examined for skin lesions and presence ofS. scabieiby thorough visual examination at autopsy and skin scrapings. Samples of blood‐tinted body liquid from the abdomen or thorax cavity were collected and analysed by the indirect ELISA. The relative sensitivity and specificity of the ELISA at different cut‐offs (OD values) were estimated by comparing the test results to the infection status as determined by examination and skin scrapings. The highest combination of relative sensitivity and specificity, calculated based on cohort 1, was 95.4 and 100.0%, respectively. These estimates were constant for cut‐offs 0.150–0.225, which included the cut‐off based on the mean plus three standard deviations of test results from cohort 2 (0.165). It is concluded that this test can be useful in diagnosis and epidemiological studies ofS. scabieiinfection in red foxes.
Evaluation of the effects of topical tripeptide‐copper complex and zinc oxide on open‐wound healing in rabbits
Authors: Cangul I. Taci , Gul Nihal Y. , Topal Ayse , Yilmaz Rahsan 
Published: November 2006

AbstractIn this study the clinical and histopathological effects of topically applied tripeptide‐copper complex (TCC) and zinc oxide on open‐wound healing in rabbits was evaluated. Eighteen New Zealand rabbits were divided into three groups: TCC, zinc oxide and no treatment. One full thickness wound was created on each side of the dorsal midline in each rabbit. Wound margins were traced on days 0, 7, 14, and 21 and topical TCC and zinc oxide were applied daily for 21 days to each rabbit in the respective treatment groups. The mean unhealed wound area was significantly smaller in the TCC than in the zinc oxide group on day 7, but it was significantly smaller in the TCC group than in to the control group on days 7, 14 and 21. The mean percentage of wound contraction on day 7 was significantly higher in the TCC than in the zinc oxide group; however, it was significantly higher in the TCC group than in the control group on days 7, 14 and 21. Median time for the coverage of the wound bed with granulation tissue was significantly shorter in the TCC group than in the other groups. Filling of the open wound with granulation tissue to skin level was significantly slower in the control group than in the other two groups. Neutrophil counts decreased regardless of the group in parallel with healing, while neovascularization was best observed in the TCC group. The results suggest that TCC is a better choice in the treatment protocols of open wounds in rabbits than zinc oxide.
Putting informed and shared decision making into practice
Authors: Towle Angela , Godolphin William , Grams Garry , LaMarre Amanda 
Published: November 2006

AbstractObjective  To investigate the practice, experiences and views of motivated and trained family physicians as they attempt to implement informed and shared decision making (ISDM) in routine practice and to identify and understand the barriers they encounter.Background  Patient involvement in decision making about their health care has been the focus of much academic activity. Although significant conceptual and experimental work has been done, ISDM rarely occurs. Physician attitudes and lack of training are identified barriers.Design  Qualitative analysis of transcripts of consultations and key informant group interviews.Settings and participants  Six family physicians received training in the ISDM competencies. Audiotapes of office consultations were made before and after training. Transcripts of consultations were examined to identify behavioural markers associated with each competency and the range of expression of the competencies. The physicians attended group interviews at the end of the study to explore experiences of ISDM.Results  The physicians liked the ISDM model and thought that they should put it into practice. Evidence from transcripts indicated they were able to elicit concerns, ideas and expectations (although not about management) and agree an action plan. They did not elicit preferences for role or information. They sometimes offered choices. They had difficulty achieving full expression of any of the competencies and integrating ISDM into their script for the medical interview. The study also identified a variety of competency‐specific barriers.Conclusion  A major barrier to the practice of ISDM by motivated physicians appears to be the need to change well‐established patterns of communication with patients.
Towards genetic markers in animal populations as biomonitors for human‐induced environmental change
Authors: Hoffmann Ary A. , Daborn Phillip J. 
Published: November 2006

AbstractGenetic markers provide potentially sensitive indicators of changes in environmental conditions because the genetic constitution of populations is normally altered well before populations become extinct. Genetic indicators in populations include overall genetic diversity, genetic changes in traits measured at the phenotypic level, and evolution at specific loci under selection. While overall genetic diversity has rarely been successfully related to environmental conditions, genetically based changes in traits have now been linked to the presence of toxins and both local and global temperature shifts. Candidate loci for monitoring stressors are emerging from information on how specific genes influence traits, and from screens of random loci across environmental gradients. Drosophila research suggests that chromosomal regions under recent intense selection can be identified from patterns of molecular variation and a high frequency of transposable element insertions. Allele frequency changes at candidate loci have been linked to pesticides, pollutants and climate change. Nevertheless, there are challenges in interpreting allele frequencies in populations, particularly when a large number of loci control a trait and when interactions between alleles influence trait expression. To meet these challenges, population samples should be collected for longitudinal studies, and experimental programmes should be undertaken to link variation at candidate genes to ecological processes.
Thirty years of plant transformation technology development
Authors: Vain Philippe 
Published: November 2006

SummaryTechnology development is seminal to many aspects of basic and applied plant transgenic science. Through the development and commercialization of genetically modified crops, the evolution of plant transgenic technologies is also relevant to society as a whole. In this study, literature statistics were used to uncover trends in the development of these technologies. Publication volume and impact (citation) over the past 30 years were analysed with respect to economic zones, countries, species and DNA delivery method. This revealed that, following a dramatic expansion in the 1980s, publications focusing on the development of transgenic technology have been slowing down worldwide since the early mid‐1990s, except in a few leading Asian countries. The implications of these trends on the future of plant transgenic science as a whole are discussed.