bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE REACTION OF CREATINE KINASE WITH DITHIOBISNITROBENZOIC ACID
Authors: O'Sullivan W. J. 
Published: August 2010

Two derivatives of creatine kinase (CrK) have been formed by reaction with the sul‐phydryl group reagent, dithiobisnitrobenzoic acid (DTNB). In the first derivative, TNB(2) ‐CrK, the two essential ‐SH groups of the active dimer form were blocked. The inactivated enzyme had similar physico‐chemical properties to the native enzyme, including the ability to bind manganese‐nucleotide substrates. Full activity could be restored by treatment with dithiothreitol. It is suggested that TNB(2)‐CrK could serve as a convenient means of protecting the essential ‐SH groups of CrK, while the effects of other group‐specific reagents are explored. A second derivative, TNB(8)‐CrK, was formed by carrying out the reaction in the presence of 8 M urea. Under these conditions, the CrK dimer is dissociated into monomers with exposure of a further six ‐SH groups. After removal of the urea, a significant concentration of the protein remained in solution in the monomer form. This derivative bound Mn2+ strongly but the nucleotide binding site was destroyed. A role for the “buried” sulphydryl groups in the formation of the stable dimer form of creatine kinase is indicated.
MOUSE INSULINS — SEPARATION AND STRUCTURES
Authors: Markussen Jan 
Published: August 2010

Two major components were detected by disc electrophoresis in twice crystallized mouse insulin. Gel filtration experiments indicated that the two components were two insulins rather than proinsulin and insulin. The components were separated by ion‐exchange chromatography, and amino acid analysis showed both components to be insulin, differing in two amino acids. The mouse insulins were named Mouse I and Mouse II insulin by analogy with Rat I and Rat II insulin in accordance with the electrophoretic mobilities. Performic acid oxidation followed by separation of the A and B chains, and amino acid analysis of the separated chains showed both differences to be present in the B chains whereas the A chains were identical. Trypsinization of the B chains followed by separation of the tryptic peptides and amino acid analysis of the peptides yielded the following results: B 1 to B 3 were identical. B 4 to B 22 differed in one amino acid, mouse I having one proline and no serine, mouse II having one serine and no proline. Finally, free serine B 30 plus a heptapeptide (B 23‐B 29) containing one lysine and no methionine was obtained from mouse I, whereas mouse II yielded an octapeptide (B 23‐B 30) containing one methionine and no lysine. Mouse II insulin displayed amino acid compositions identical with those of rat II insulin in regard to the A chain, the B chain, and the tryptic peptides from the B chain.
STUDY OF HYDROGEN BONDS IN AMINO ACIDS AND PEPTIDES*
Authors: Ramakrishnan C. , Prasad Nageshwar 
Published: August 2010

An analysis of the various parameters associated with N‐H… O type of hydrogen bonds has been made using data from reported crystal structures of amino acids and simple peptides. The different parameters at the donor and the acceptor ends have been suitably defined and evaluated. In some cases the analysis is done depending upon the chargedness or other characteristics of the donor and acceptor groups. Histograms giving the distribution of these parameters have been drawn and possible conclusions arrived at: 1. The distribution shows a maximum between 2.8 A and 2.9 A for the charged donor group and 2.9 A and 3.0 A for the uncharged donor group and is probably not dependent upon the charge on the acceptor group. 2. The angle between the directions CO and O. N tends to lie between two cones about C O with semi‐vertical angles 40 and 70°. The orientation of the directions O. N and O. H with respect to the lone pair orbital directions on the acceptor oxygen atoms are analysed in detail using spherical polar coordinates. The analysis indicates that the group NH has a very strong tendency to point towards the acceptor oxygen atom. A general feature has been found in that the direction N‐H tends to be closer to an orbital if the oxygen is an acceptor of two hydrogen bonds, while the direction tends to lie in between the orbitals when the acceptor oxygen is the receipient of only one hydrogen bond. The possible explanation of this on the basis of lone pair interaction is briefly discussed.
APPLICATION OF POLAROGRAPHY AND CONTROLLED POTENTIAL ELECTROLYSIS IN PEPTIDE SYNTHESIS
Authors: Capobianco Giulio , Vidali Giorgio 
Published: August 2010

Electrolysis of amino acids and peptides protected on the amino function has been conducted. In aqueous medium the nitro group of w‐nitro arginine and o‐nitro sulfenyl are selectively removed by means of controlled potential electrolysis, whereas phthaloyl, tosyl, formyl, acetoacetyl, xanthyl, benzyloxycarbonyl, t‐butoxycarbonyl are stable under the electrolytic condition employed.
Initiation of a screening protocol for polyoma virus results in a decreased rate of opportunistic non‐BK viral disease after renal transplantation
Authors: Koleilat I. , Kushnir L. , Gallichio M. , Conti D.J. 
Published: August 2010

I. Koleilat, L. Kushnir, M. Gallichio, D.J. Conti. Initiation of a screening protocol for polyoma virus results in a decreased rate of opportunistic non‐BK viral disease after renal transplantation. Transpl Infect Dis 2011: 13: 1–8. All rights reservedBackground. Polyoma BK virus nephropathy (PVN) is a leading cause of renal allograft injury and loss. The mainstay of treatment, as there are no target therapies approved by the US Food & Drug Administration, is reduction in immunosuppression. However, current approaches are shifting to screening for viremia as an indicator of oncoming nephropathy, with subsequent reduction in immunotherapy. We attempted not only to replicate these data but also to evaluate the utility of polyoma viremia as a surrogate marker for overimmunosuppression in general, thus allowing prevention not only of PVN but also of other viral opportunistic infections such as cytomegalovirus (CMV) and Epstein–Barr virus (EBV) disease.Patients and methods. We conducted a retrospective cohort analysis of renal transplant recipients at our center. The historical controls (2003–2005, n=134) had received their allograft before the institution of a monthly serum polymerase chain reaction (PCR) polyoma screening protocol. The screened cohort received their allograft afterwards (2006–2008, n=134). Screening was performed using PCR techniques with prompt reduction in immunosuppression for viremic patients. The patients were followed for the development of PVN, acute rejection, renal allograft function, and survival.Results. Polyoma viremia was noted in 16% of the screened population, with none developing PVN after prompt reduction of immunosuppression. Clearance of the viremia occurred by 6 months in 95% of the patients after reduction of immunotherapy. No patient in the screened group developed CMV or EBV disease. Of the controls, 7 (5%) developed PVN and 12 (9%) developed CMV or EBV disease, compared with none of the screened patients (P<0.05). The incidence of acute rejection was comparable between the groups (4% controls, 5% screened). No deleterious effects were noted on patient or allograft survival, allograft function (measured by serum creatinine), rates of fungal infection, or the rate of post‐transplant lymphoproliferative disorder in the screened patients.Conclusions. Monthly PCR monitoring for BK viremia, together with a modest decrease in immunotherapy, is not only safe but also effectively prevents PVN and is associated with a significantly decreased rate of CMV and EBV disease in renal transplant patients. BK viremia may also serve as a surrogate marker for overimmunosuppression.
Prediction of low haemoglobin levels in whole blood donors
Authors: Baart A. M. , de Kort W. L. A. M. , Moons K. G. M. , Vergouwe Y. 
Published: August 2010

Background and Objectives  Each year, a relevant proportion of whole blood donors is deferred from donation because of low haemoglobin (Hb) levels. Such temporary deferrals are demoralizing, and donors may never return for a donation. Reliable predictions of Hb levels may guide the decision whether donors can be invited for the next donation. In this study, a prediction model was developed for the risk of low Hb levels.Materials and Methods  Individual data from 5191 whole blood donors were analysed; 143 donors had a low Hb level. Eleven candidate predictors were considered in logistic regression models to predict low Hb levels. The performance of the prediction model was studied with the receiver operating characteristic (ROC) curve. Internal validity was assessed with a bootstrap procedure.Results  Strong predictors were sex, seasonality, Hb level measured at the previous visit, difference in Hb levels between the previous two visits, time since the previous visit, deferral at the previous visit, and the total number of whole blood donations in the past 2 years. Internal validation showed an area under the ROC curve of 0·87.Conclusion  The developed prediction model provides accurate discrimination between donors with low and appropriate Hb levels. The model predictions may be valuable to determine whether donors can be invited for a next donation, or whether some interventions such as postponement of the invitation are warranted. Potentially, this could decrease the number of donor deferrals for low Hb levels.
Egg Colour Covaries with Female Expression of a Male Ornament in the Spotless Starling (Sturnus unicolor)
Authors: López‐Rull Isabel , Celis Patricia , Gil Diego 
Published: August 2010

AbstractThe sexually selected egg colour hypothesis (SSECH) proposes that egg colouration is as a post‐mating sexually selected signal of female phenotypic quality, maintained by a higher allocation of paternal care. Similarly, some female traits can reflect genetic quality or condition and males could use this information in mate choice or in modulating parental investment. In our study, we examined the correlation of individual variation in egg colouration with female expression of a male ornament and how male feeding covaried with these two female traits in the spotless starling, in which egg colour varies widely between clutches and where both sexes possess showy throat feathers that are age dependent and that may signal individual quality. According to the SSECH, high‐quality females (females with longer throat feathers) are expected to lay more colourful eggs than low‐quality females and males should modify their feeding behaviour accordingly. By means of a principal component analysis, we found that most of the variation in egg colouration was due to brightness differences, and in a lower proportion to chromatic variation. Chromatic variation reflected a ultraviolet (UV) vs. greenness trade‐off and was positively associated with throat feather length: females with larger throat feathers laid eggs with higher UV and lower green reflectance. However, egg brightness was not related to female feather length, as the SSECH would predict. Male feedings were positively related to female throat feather length and negatively related to chromatic variation, meaning that males contributed more to nests of females with long throat feathers who laid eggs with higher UV and lower green reflectance. In conclusion, our data provide mixed support for the SSECH: although egg chromatic variation was related to female expression of a male ornament and male parental care, we found no evidence that egg brightness was involved in these processes.
Wing Colour Properties do not Reflect Male Condition in the American Rubyspot (Hetaerina americana)
Authors: Contreras‐Garduño Jorge , Buzatto Bruno A. , Abundis Lizeth , Nájera‐Cordero Karla , Córdoba‐Aguilar Alex 
Published: August 2010

AbstractAdult males of the American rubyspot (Hetaerina americana) dispute riverine territories where females arrive to mate. On the wing basis, these males bear a red pigmentation spot whose area correlates with territorial disputes and mating rate: males with larger spots are more successful. This is explained by the fact that spot size correlates with fat muscular reserves which fuel flight during territorial intrusions. To further our understanding of sexual selection acting on the spot, here we have examined possible differences in three spot colour properties (red chroma, hue and brightness) in three distinct adult male ages [young, middle‐aged (when males are more likely to defend a territory) and old], social status (territorial and non‐territorial in middle‐aged males), and under two potentially, energetically and costly situations: when faced with an immune challenge [comparing a nylon‐implanted male group vs. a non‐implanted male group in two ages, teneral (previous to colour formation) and middle‐aged] and low diet levels (comparing a male set of middle‐aged animals that received food ad libitum vs. a male set that received no food). Our results indicate no change in colour properties across any of these comparisons. Taken together, these and previous results suggest that only spot size but not the spot characteristics we measured here, is sexually selected in males of this species at least in terms of pre‐copulatory male–male competition. That some of these colour properties have been related to male condition in other calopterygid damselflies cannot be generalized to the American rubyspot.
Sources of Selection on Signal Timing in a Tree Frog
Authors: Höbel Gerlinde , Gerhardt H. Carl 
Published: August 2010

AbstractSignal‐timing adjustment is common in communally signaling species, and there is large variation in signal‐timing formats found in nature. We conducted a survey of geographic variation in female signal‐timing preferences and male signaling behavior of a tree frog to test predictions of two hypotheses about the sources of selection acting on signal‐timing behavior. We found that female preferences are important in shaping male signal timing, affecting the absolute placement of signals relative to the temporal limits of female preferences. Variation in other signal characters, particularly signal period, also affects signal timing, albeit in a more complicated pattern: the influence of signal period on signal timing varied between populations. Overall, our findings indicate that the evolution of male signal‐timing behavior is strongly influenced by female preferences and by an interaction with other aspects of male signaling behavior such as male signal period.
Does the Complexity of the Task Influence Manual Laterality in De Brazza’s Monkeys (Cercopithecus neglectus)?
Authors: Schweitzer Cécile , Bec Philippe , Blois‐Heulin Catherine 
Published: August 2010

AbstractWe assessed the manual preferences of 12 De Brazza’s monkeys (Cercopithecus neglectus) in spontaneous feeding situations and in two different coordinated bimanual tasks that were not visually guided. We recorded the hand used by each subject for 22 spontaneous activities, hand and digits use while extracting peanut butter from a hollow tube (tube task) and the hand used to extract candies from hanging plastic balls (ball task). Spontaneous activities revealed individual manual preferences but no population‐level biases. For both experimental tasks, all subjects were lateralized in their hand use. We found a left bias at the group level for the tube task, but no group‐level asymmetry for the ball task. Experimental tasks induced greater strength of laterality than did spontaneous activities. Although the size of our sample did not allow us to draw any conclusions concerning manual preference at the population level, this study stresses the importance of coordinated bimanual tasks to reveal manual laterality in non‐human primates.
An Experimental Analysis of Spatial Position Effects on Foraging and Vigilance in Brown‐Headed Cowbird flocks
Authors: Fernández‐Juricic Esteban , Beauchamp Guy 
Published: August 2010

AbstractSeveral observational studies have found that the costs and benefits of social foraging vary as a function of spatial position in the group. However, it is difficult to make mechanistic inferences because several confounding factors, such as food deprivation levels, food availability, neighbor distance, and group size can mask or amplify spatial position effects. We attempted to address experimentally the effect of spatial position on foraging and vigilance in a group, controlling for many confounding factors. We used enclosures that restricted physical but not visual interactions between brown‐headed cowbirds and manipulated spatial position, flock size, and neighbor distance. Pecking rate (number of pecks per trial duration) was not related with position, but instantaneous pecking rate (number of pecks per foraging bout duration) was higher at the edge. The proportion of time spent head‐up (scanning and food‐handling) was also higher at the edge. For pecking rate and proportion of time spent scanning, changes in neighbor distance influenced the behavior of edge birds to a lesser extent than central birds. These results suggest that cowbirds at the edge perceived greater predation risk and that during the limited foraging time available, edge birds tried to compensate by foraging at a faster rate.
The Influence of Tail Autotomy on the Escape Response of the Cape Dwarf Gecko, Lygodactylus capensis
Authors: Medger Katarina , Verburgt Luke , Bateman Philip W. 
Published: August 2010

AbstractTail autotomy as a defence against predators occurs in many species of lizard. Although tail autotomy may provide an immediate benefit in terms of survival it may nevertheless be costly due to other functions of the tail. For example, tail autotomy may affect the locomotory performance of lizards during escape. We investigated the influence of tail autotomy on the escape performance of the Cape Dwarf Gecko, Lygodactylus capensis, on a vertical and a horizontal surface. Autotomized geckos were significantly slower than intact geckos during vertical escape, whereas tail autotomy did not influence the horizontal escape speed. Backward falling of the autotomized geckos on the vertical platform may explain the reduced speed. In addition, tail autotomy did not significantly affect body curvature and stride length of the geckos. The observed decrease of escape speed on a vertical platform may influence the habitat use and behaviour of these geckos. Ecological consequences resulting from tail autotomy are discussed in light of these findings.
Mate Guarding in the Androdioecious Clam Shrimp Eulimnadia texana: Male Assessment of Hermaphrodite Receptivity
Authors: Weeks Stephen C. , Benvenuto Chiara 
Published: August 2010

AbstractPrecopulatory mate guarding primarily occurs when males encounter receptive females at a low enough rate that such females become a valuable resource once encountered. Such circumstances are common in aquatic crustaceans wherein females are only receptive for a short period directly after molting. In these species, males commonly mate guard by physically attaching themselves to their prospective mates for hours to days at a time. To be effective in mate guarding, males must be able to assess the time to receptivity in their mates, which is commonly via chemical cues associated with molting. Clam shrimp in the genus Eulimnadia exhibit mate guarding, but with an important variation: these species are mixtures of males and hermaphrodites (androdioecy) rather than males and females. Nonetheless, the mate guarding behaviors of these shrimp are much the same as in other aquatic crustaceans. In this study, three projects were undertaken to determine the ability of Eulimnadia texana males to assess hermaphroditic receptivity. Males were found to be unable to assess receptivity without physically contacting hermaphrodites. However, after physical contact, males spent a significantly greater amount of time guarding receptive relative to non‐receptive hermaphrodites. Additionally, male interest in mate guarding was highest during the period between the dropping of one clutch of eggs and the extrusion of the following clutch. Because this period is also associated with hermaphroditic molting, it is consistent with the notion that males cue into chemicals associated with molting to determine hermaphroditic receptivity. These findings are consistent with previous studies of mating behavior in this species, and we discuss their importance to future tests of optimal mate guarding planned for these shrimp.
The Bold and the Variable: Fish with High Heterozygosity Act Recklessly in the Vicinity of Predators
Authors: Vilhunen Sampsa , Tiira Katriina , Laurila Anssi , Hirvonen Heikki 
Published: August 2010

AbstractVariation in the innate behavioral response to predation threat is often assumed to reflect genetic differences among the prey individuals. To date, no published results, however, exist that would offer explanation for the origin of this behavioral variation within populations. Using microsatellites as markers, we estimated the genetic variability of juvenile brown trout (Salmo trutta) individuals whose behavior had been individually recorded in a trade‐off situation where both predator chemical cues and food were present. Mean overall heterozygosity and the internal relatedness of fish associated significantly with their activity and foraging, so that the genetically more variable individuals showed more risk‐prone behavior under predation risk. No association between genetic variability and behavior was found in trials where predator odors were not present. These results were consistent over the three study populations of brown trout with different backgrounds, suggesting that the phenomenon is of general nature in this species. Of the possible mechanisms suggested to enable the existence of the positive association between neutral microsatellite variation and fitness‐related trait, the local effect hypothesis gained more support from our data than the general effect hypothesis.
Aerial Contests, Sexual Selection and Flight Morphology in Solitary Pompilid Wasps
Authors: Kemp Darrell J. , Alcock John 
Published: August 2010

AbstractAerial contest competition has proven to be a challenging phenomenon to interpret in many territorial insects. Because the duels often consist of elaborate and/or high speed ascending maneuvers, the hypothesis that they are settled due to asymmetries in flight performance is intuitively appealing. We evaluated this hypothesis by contrasting differences in known morphological determinants of flight performance between (1) residents vs. non‐residents of the territorial wasp, Hemipepsis ustulata and between (2) H. ustulata vs. a non‐territorial relative, Pepsis thisbe. In the first contrast, resident male H. ustulata were seen to be larger, and had a tendency for reduced wing loading, but they did not possess greater flight musculature or wing aspect ratios (i.e., more elongated wings) than their non‐resident counterparts. In the second contrast, male H. ustulata exhibited clearly greater flight musculature and greater sexual dimorphism in this parameter (males more muscular), and also exhibited a slight tendency for greater wing loading and smaller aspect ratios than males of the patrolling species P. thisbe. Interestingly, although size is linked with territorial success in H. ustulata, males of this species were not larger than male P. thisbe, nor did the former species exhibit greater sexual size dimorphism. These results do not support the hypothesis that the repeated ascending contests of H. ustulata require, and select for, a high acceleration design. However, the observed intraspecific patterns of flight musculature suggest that high acceleration is favored in males of the perching species, perhaps for the ability to intercept passing receptive females.