bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Structural, DFT, and Cytotoxicity Studies of CuII and NiII Complexes with 3-Aminopyrazole Derivatives
Authors: Holló Berta , Leovac Vukadin M. , Bombicz Petra , Kovács Attila , Jovanović Ljiljana S. , Bogdanović Gordana , Kojić Vesna , Divjaković Vladimir , Joksović Milan D. , Szécsényi Katalin Mészáros
Published: November 2010

Template synthesis of N,N′-bis(4-acetyl-5-methylpyrazole-3-yl)formamidine (ampf) was performed starting from 4-acetyl-3-amino-5-methylpyrazole (aamp) and CH(OC2H5)3 in methanol in the presence of CuCl2, Cu(NO3)2, or Ni(NO3)2. The ligand was isolated in coordinated form as [Cu(ampf)Cl2], [Cu(ampf)(MeOH)(NO3)2]MeOH, and [Ni(ampf)(MeOH)2(NO3)]NO3 correspondingly. The compounds were characterized by elemental analysis, Fourier-transform IR and electronic spectroscopy, thermal analysis, single-crystal X-ray diffraction, and quantum chemical (density functional theory) calculations. The density functional theory calculations provided information on the metal–ligand interactions in the complexes and assisted the assignment of the FT-IR spectra. The antiproliferative activity of the complexes and the ligand precursor, aamp, was tested against human myelogenous leukaemia K562, colon adenocarcinoma HT29, and cervix carcinoma HeLa.
Synthesis of Azide-alkyne Fragments for 'Click' Chemical Applications. Formation of Chiral 1,4-Disubstituted-(β-alkyl)-γ-1,2,3-triazole Scaffolds from Orthogonally Protected Chiral β-Alkyl-trialkylsilyl-γ-pentynyl Azides and Chiral β-Alkyl-γ-pentynyl-alcohols
Authors: Montagnat Oliver D. , Lessene Guillaume , Hughes Andrew B.
Published: November 2010

A library of chiral γ-pentynyl alcohols and γ-pentynyl azides was made using the SuperQuat auxiliary. Coupling of the free alkynes with the azides by Huisgen 1,3-dipolar cycloaddition provided chiral oligomeric 1,4-disubstituted-1,2,3-triazoles as possible peptidomimetic compounds.
Most harmful algal bloom species are vitamin B1and B12auxotrophs
Authors: Tang Ying Zhong , Koch Florian , Gobler Christopher J.
Published: November 2010

Eutrophication can play a central role in promoting harmful algal blooms (HABs), and therefore many HAB studies to date have focused on macronutrients (N, P, Si). Although a majority of algal species require exogenous B vitamins (i.e., auxotrophic for B vitamins), the possible importance of organic micronutrients such as B vitamins (B1, B7, B12) in regulating HABs has rarely been considered. Prior investigations of vitamins and algae have examined a relatively small number of dinoflagellates (n= 26) and a paucity of HAB species (n= 4). In the present study, the vitamin B1, B7, and B12requirements of 41 strains of 27 HAB species (19 dinoflagellates) were investigated. All but one species (two strains) of harmful algae surveyed required vitamin B12, 20 of 27 species required B1, and 10 of 27 species required B7, all proportions higher than the previously reported for non-HAB species. Half-saturation (Ks) constants of several HAB species for B1and B12were higher than those previously reported for other phytoplankton and similar to vitamin concentrations reported in estuaries. Cellular quotas for vitamins suggest that, in some cases, HAB demands for vitamins may exhaust standing stocks of vitamins in hours to days. The sum of these findings demonstrates the potentially significant ecological role of B-vitamins in regulating the dynamics of HABs.
Error-prone translesion synthesis mediates acquired chemoresistance
Authors: Xie Kun , Doles Jason , Hemann Michael T. , Walker Graham C.
Published: November 2010

The development of cancer drug resistance is a persistent clinical problem limiting the successful treatment of disseminated malignancies. However, the molecular mechanisms by which initially chemoresponsive tumors develop therapeutic resistance remain poorly understood. Error-prone translesional DNA synthesis (TLS) is known to underlie the mutagenic effects of numerous anticancer agents, but little is known as to whether mutation induced by this process is ultimately relevant to tumor drug resistance. Here, we use a tractable mouse model of B-cell lymphoma to interrogate the role of error-prone translesional DNA synthesis in chemotherapy-induced mutation and resistance to front-line chemotherapy. We find that suppression of Rev1, an essential TLS scaffold protein and dCMP transferase, inhibits both cisplatin- and cyclophosphamide-induced mutagenesis. Additionally, by performing repeated cycles of tumor engraftment and treatment, we show that Rev1 plays a critical role in the development of acquired cyclophosphamide resistance. Thus, chemotherapy not only selects for drug-resistant tumor population but also directly promotes the TLS-mediated acquisition of resistance-causing mutations. These data provide an example of an alteration that prevents the acquisition of drug resistance in tumors in vivo. Because TLS also represents a critical mechanism of DNA synthesis in tumor cells following chemotherapy, these data suggest that TLS inhibition may have dual anticancer effects, sensitizing tumors to therapy as well as preventing the emergence of tumor chemoresistance.
THE UBIQUITY OF THE RAPID NEUTRON-CAPTURE PROCESS*
Authors: Roederer Ian U. , Cowan John J. , Karakas Amanda I. , Kratz Karl-Ludwig , Lugaro Maria , Simmerer Jennifer , Farouqi Khalil , Sneden Christopher
Published: November 2010

To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn, Z= 30), yttrium (Y, Z= 39), lanthanum (La, Z= 57), europium (Eu, Z= 63), and lead (Pb, Z= 82). Our sample of 161 metal-poor stars includes new measurements from 88 high-resolution and high signal-to-noise spectra obtained with the Tull Spectrograph on the 2.7 m Smith Telescope at the McDonald Observatory, and other abundances are adopted from the literature. We use models of the s-process in asymptotic giant branch stars to characterize the high Pb/Eu ratios produced in the s-process at low metallicity, and our new observations then allow us to identify a sample of stars with no detectable s-process material. In these stars, we find no significant increase in the Pb/Eu ratios with increasing metallicity. This suggests that s-process material was not widely dispersed until the overall Galactic metallicity grew considerably, perhaps even as high as [Fe/H] =−1.4, in contrast with earlier studies that suggested a much lower mean metallicity. We identify a dispersion of at least 0.5 dex in [La/Eu] in metal-poor stars with [Eu/Fe] <+0.6 attributable to the r-process, suggesting that there is no unique “pure” r-process elemental ratio among pairs of rare earth elements. We confirm earlier detections of an anti-correlation between Y/Eu and Eu/Fe bookended by stars strongly enriched in the r-process (e.g., CS 22892–052) and those with deficiencies of the heavy elements (e.g., HD 122563). We can reproduce the range of Y/Eu ratios using simulations of high-entropy neutrino winds of core-collapse supernovae that include charged-particle and neutron-capture components of r-process nucleosynthesis. The heavy element abundance patterns in most metal-poor stars do not resemble that of CS 22892–052, but the presence of heavy elements such as Ba in nearly all metal-poor stars without s-process enrichment suggests that the r-process is a common phenomenon.
Improving evolutionary models of protein interaction networks
Authors: Gibson Todd A. , Goldberg Debra S.
Published: November 2010

Motivation: Theoretical models of biological networks are valuable tools in evolutionary inference. Theoretical models based on gene duplication and divergence provide biologically plausible evolutionary mechanics. Similarities found between empirical networks and their theoretically generated counterpart are considered evidence of the role modeled mechanics play in biological evolution. However, the method by which these models are parameterized can lead to questions about the validity of the inferences. Selecting parameter values in order to produce a particular topological value obfuscates the possibility that the model may produce a similar topology for a large range of parameter values. Alternately, a model may produce a large range of topologies, allowing (incorrect) parameter values to produce a valid topology from an otherwise flawed model. In order to lend biological credence to the modeled evolutionary mechanics, parameter values should be derived from the empirical data. Furthermore, recent work indicates that the timing and fate of gene duplications are critical to proper derivation of these parameters.

Results: We present a methodology for deriving evolutionary rates from empirical data that is used to parameterize duplication and divergence models of protein interaction network evolution. Our method avoids shortcomings of previous methods, which failed to consider the effect of subsequent duplications. From our parameter values, we find that concurrent and existing existing duplication and divergence models are insufficient for modeling protein interaction network evolution. We introduce a model enhancement based on heritable interaction sites on the surface of a protein and find that it more closely reflects the high clustering found in the empirical network.

Contact:  Debra@Colorado.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Intraoperative Recruitment Maneuver Reverses Detrimental Pneumoperitoneum-induced Respiratory Effects in Healthy Weight and Obese Patients Undergoing Laparoscopy
Authors: Futier Emmanuel , Constantin Jean-Michel , Pelosi Paolo , Chanques Gerald , Kwiatkoskwi Fabrice , Jaber Samir , Bazin Jean-Etienne
Published: November 2010

Background

Pulmonary function is impaired during pneumoperitoneum mainly as a result of atelectasis formation. We studied the effects of 10 cm H2O of positive end-expiratory pressure (PEEP) and PEEP followed by a recruitment maneuver (PEEP+RM) on end-expiratory lung volume (EELV), oxygenation and respiratory mechanics in patients undergoing laparoscopic surgery.

Methods

Sixty consecutive adult patients (30 obese, 30 healthy weight) in reverse Trendelenburg position were prospectively studied. EELV, static elastance of the respiratory system, dead space, and gas exchange were measured before and after pneumoperitoneum insufflation with zero end-expiratory pressure, with PEEP alone, and with PEEP+RM. Results are presented as mean ± SD.

Results

Pneumoperitoneum reduced EELV (healthy weight, 1195 ± 405 vs. 1724 ± 774 ml; obese, 751 ± 258 vs. 886 ± 284 ml) and worsened static elastance and dead space in both groups (in all P < 0.01 vs. zero-end expiratory pressure before pneumoperitoneum) whereas oxygenation was unaffected. PEEP increased EELV (healthy weight, 570 ml, P < 0.01; obese, 364 ml, P < 0.01) with no effect on oxygenation. Compared with PEEP alone, EELV and static elastance were further improved after RM in both groups (P < 0.05), as was oxygenation (P < 0.01). In all patients, RM-induced change in EELV was 16% (P = 0.04). These improvements were maintained 30 min after RM. RM-induced changes in EELV correlated with change in oxygenation (r = 0.42, P < 0.01).

Conclusion

RM combined with 10 cm H2O of PEEP improved EELV, respiratory mechanics, and oxygenation during pneumoperitoneum whereas PEEP alone did not.
Impact of a Comprehensive Safety Initiative on Patient-controlled Analgesia Errors
Authors: Paul James E. , Bertram Barbara , Antoni Karen , Kampf Marianne , Kitowski Terri , Morgan Aled , Cheng Ji , Thabane Lehana
Published: November 2010

Background

Adverse drug events related to patient-controlled analgesia (PCA) place patients at risk.

Methods

We reviewed all critical incident reports at three tertiary care hospitals dated January 1, 2002, to February 28, 2009. In this longitudinal cohort study, critical incidents attributable to PCA errors were identified, and each incident was investigated. A safety intervention was implemented in February 2006 and involved new PCA pumps, new preprinted physician orders, nursing and patient education, a manual independent double-check, and a formal nursing transfer of accountability.

Results

A total of 25,198 patients were treated with PCA during this study, and 62 errors were found (0.25%), with 21 (0.08%) involving pump programming. All errors occurred before the safety interventions were put in place. Compared with the preintervention period, the odds ratio of a PCA error postintervention was 0.28 (95% CI = 0.14, 0.53; P < 0.001) whereas the odds ratio of a pump-programming error postintervention was 0.05 (95% CI = 0.001, 0.30; P < 0.001). Programming the wrong drug concentration was the most common programming error (10 of 21). Improper setup of intravenous tubing was also common (8 of 62), with one incident leading to respiratory arrest. Most PCA errors resulted in no harm, but there was negative impact to patients 34% of the time.

Conclusion

At less than 1%, the incidence of PCA errors is relatively low. Most errors occur during PCA administration. Safety can be improved by addressing equipment, education, and process issues.
Positive End-expiratory Pressure Redistributes Regional Blood Flow and Ventilation Differently in Supine and Prone Humans
Authors: Petersson Johan , Ax Malin , Frey Joana , Sánchez-Crespo Alejandro , Lindahl Sten G. E. , Mure Margareta
Published: November 2010

Background

Animal studies have demonstrated an interaction between posture and the effect of positive end-expiratory pressure (PEEP) on regional ventilation and lung blood flow. The aim of this study was to explore this interaction in humans.

Methods

Regional lung blood flow and ventilation were compared between mechanical ventilation with and without PEEP in the supine and prone postures. Six normal subjects were studied in each posture. Regional lung blood flow was marked with In-labeled macroaggregates and ventilation with Technegas (Tc). Radiotracer distributions were mapped using quantitative single-photon emission computed tomography.

Results

In supine subjects, PEEP caused a similar redistribution of both ventilation and blood flow toward dependent (dorsal) lung regions, resulting in little change in the V/Q correlation. In contrast, in prone subjects, the redistribution toward dependent (ventral) regions was much greater for blood flow than for ventilation, causing increased V/Q mismatch. Without PEEP, the vertical ventilation-to-perfusion gradient was less in prone postures than in supine, but with PEEP, the gradient was similar.

Conclusions

During mechanical ventilation of healthy volunteers, the addition of PEEP, 10 cm H2O, causes redistribution of both lung blood flow and ventilation, and the effect is different between the supine and prone postures. Our results suggest that the addition of PEEP in prone might be less beneficial than in supine and that optimal use of the prone posture requires reevaluation of the applied PEEP.
Does foreplay matter?
Gammarus pulex
females may benefit from long-lasting precopulatory mate guarding
Authors: Galipaud Matthias , Dechaume-Moncharmont François-Xavier , Oughadou Abderrahim , Bollache Loïc
Published: November 2010

Precopulatory mate guarding (PCMG) is generally assumed to be costly for both sexes. However, males may gain by displaying long-lasting mate guarding under strong male–male competition. Surprisingly, the potential for females to benefit from being held by males has been largely overlooked in previous studies. In
Gammarus pulex
, an amphipod crustacean, PCMG lasts several weeks, yet females are described as bearing only cost from such male mating strategy. We investigated potential female benefits by assessing the effect of mate guarding on her intermoult duration. Unpaired females had longer intermoult duration than paired females. Intermoult duration clearly decreased when paired females engaged in early and long-lasting mate guarding. In addition, short intermoults and long-lasting mate guarding had no effect on egg number. These results highlight a potential benefit associated with PCMG for
G. pulex
females, suggesting that the strength of an intersexual conflict over its duration may be overestimated.
Spatial ecology across scales
Authors: Hastings Alan , Petrovskii Sergei , Morozov Andrew
Published: November 2010

The international conference ‘Models in population dynamics and ecology 2010: animal movement, dispersal and spatial ecology’ took place at the University of Leicester, UK, on 1–3 September 2010, focusing on mathematical approaches to spatial population dynamics and emphasizing cross-scale issues. Exciting new developments in scaling up from individual level movement to descriptions of this movement at the macroscopic level highlighted the importance of mechanistic approaches, with different descriptions at the microscopic level leading to different ecological outcomes. At higher levels of organization, different macroscopic descriptions of movement also led to different properties at the ecosystem and larger scales. New developments from Levy flight descriptions to the incorporation of new methods from physics and elsewhere are revitalizing research in spatial ecology, which will both increase understanding of fundamental ecological processes and lead to tools for better management.
Reynolds averaged Navier–Stokes modelling of long waves induced by a transient wave group on a beach
Authors: Lara Javier L. , Ruju Andrea , Losada Inigo J.
Published: November 2010

This paper presents the numerical modelling of the cross shore propagation of infragravity waves induced by a transient focused short wave group over a sloping bottom. A dataset obtained through new laboratory experiments in the wave flume of the University of Cantabria is used to validate the Reynolds averaged Navier–Stokes type model IH-2VOF. A new boundary condition based on the wave maker movement used in the experiments is implemented in the model. Shoaling and breaking of short waves as well as the enhancement of long waves and the energy transfer to low-frequency motion are well addressed by the model, proving the high accuracy in the reproduction of surf zone hydrodynamics. Under the steep slope regime, a long wave trough is radiated offshore from the breakpoint. Numerical simulations conducted for different bottom slopes and short wave steepness suggest that this low-frequency breakpoint generated wave is controlled by both the bed slope parameter and the Iribarren number. Moreover, the numerical model is used to investigate the influence that a large flat bottom induces on the propagation pattern of long waves.
Resonant instability in two-dimensional vortex arrays
Authors: Luzzatto-Fegiz Paolo , Williamson Charles H. K.
Published: November 2010

We examine conditions for the development of an oscillatory instability in two-dimensional vortex arrays. By building on the theory of Krein signatures for Hamiltonian systems, and considering constraints owing to impulse conservation, we show that a resonant instability (developing through coalescence of two eigenvalues) cannot occur for one or two vortices. We illustrate this deduction by examining available linear stability results for one or two vortices. Our work indicates that a resonant instability may, however, occur for three or more vortices. For these more complex flows, we propose a simple model, based on an elliptical vortex representation, to detect the onset of an oscillatory instability. We provide an example in support of our theory by examining three co-rotating vortices, for which we also perform a linear stability analysis. The stability boundary in our model is in good agreement with the full stability calculation. In addition, we show that eigenmodes associated with an overall rotation or an overall displacement of the vortices always have eigenvalues equal to zero and ±i
Ω
, respectively, where
Ω
is the angular velocity of the array. These results, for overall rotation and displacement modes, can also be used to immediately check the accuracy of a detailed stability calculation.
Four bugs on a rectangle
Authors: Chapman S. J. , Lottes James , Trefethen Lloyd N.
Published: November 2010

The idealized mathematical problem of four bugs in cyclic pursuit starting from a 2-by-1 rectangle is considered, and asymptotic formulas are derived to describe the motion. In contrast to the famous case of four bugs on a square, here the trajectories quickly freeze to essentially one dimension. After the first rotation about the centre point, the scale of the configuration has shrunk by a factor of 10427907250, and this number is then exponentiated four more times with each successive cycle. Relations to Knuth’s double-arrow notation and level-index arithmetic are discussed.
Universal power-law diet partitioning by marine fish and squid with surprising stability–diversity implications
Authors: Rossberg Axel G. , Farnsworth Keith D. , Satoh Keisuke , Pinnegar John K.
Published: November 2010

A central question in community ecology is how the number of trophic links relates to community species richness. For simple dynamical food-web models, link density (the ratio of links to species) is bounded from above as the number of species increases; but empirical data suggest that it increases without bounds. We found a new empirical upper bound on link density in large marine communities with emphasis on fish and squid, using novel methods that avoid known sources of bias in traditional approaches. Bounds are expressed in terms of the diet-partitioning function (DPF): the average number of resources contributing more than a fractionfto a consumer's diet, as a function off. All observed DPF follow a functional form closely related to a power law, with power-law exponents independent of species richness at the measurement accuracy. Results imply universal upper bounds on link density across the oceans. However, the inherently scale-free nature of power-law diet partitioning suggests that the DPF itself is a better defined characterization of network structure than link density.
Silk threads function as an ‘adhesive cleaner’ for nest space in a social spider mite
Authors: Kanazawa Miki , Sahara Ken , Saito Yutaka
Published: November 2010

Individuals of the social spider miteStigmaeopsis longuslive communally in narrow, humid nests made from silk threads and display nest sanitation behaviour through the coordinated deposition of faeces. We used artificial dust to experimentally determine that females of this species use silk threads to perform regular cleaning of the nest space and eggs. We first learned that silk-weaving behaviour is not a by-product of nest building (nest reinforcement); rather, it is actively performed as a function of cleaning the living space and eggs. Furthermore, we determined the effectiveness of the attending females by artificially manipulating their natural habitat, which is clearly connected to the cleaning behaviour by parental females. As such, we have uncovered an extraordinary new role of silk threads as devices for cleaning the nest space and/or eggs. These results strongly indicate that special adaptations for maintaining clean habitats are essential for animals to evolve aggregative social lives.
Conceptualization of above and below relationships by an insect
Authors: Avarguès-Weber Aurore , Dyer Adrian G. , Giurfa Martin
Published: November 2010

Relational rules such as ‘same’ or ‘different’ are mastered by humans and non-human primates and are considered as abstract conceptual thinking as they require relational learning beyond perceptual generalization. Here, we investigated whether an insect, the honeybee (Apis mellifera), can form a conceptual representation of an above/below spatial relationship. In experiment 1, bees were trained with differential conditioning to choose a variable target located above or below a black bar that acted as constant referent throughout the experiment. In experiment 2, two visual stimuli were aligned vertically, one being the referent, which was kept constant throughout the experiment, and the other the target, which was variable. In both experiments, the distance between the target and the referent, and their location within the visual field was systematically varied. In both cases, bees succeeded in transferring the learned concept to novel stimuli, preserving the trained spatial relation, thus showing an ability to manipulate this relational concept independently of the physical nature of the stimuli. Absolute location of the referent into the visual field was not a low-level cue used by the bees to solve the task. The honeybee is thus capable of conceptual learning despite having a miniature brain, showing that such elaborated learning form is not a prerogative of vertebrates.
Personality-dependent dispersal in the invasive mosquitofish: group composition matters
Authors: Cote Julien , Fogarty Sean , Brodin Tomas , Weinersmith Kelly , Sih Andrew
Published: November 2010

Understanding/predicting ecological invasions is an important challenge in modern ecology because of their immense economical and ecological costs. Recent studies have revealed that within-species variation in behaviour (i.e. animal personality) can shed light on the invasion process. The general hypothesis is that individuals' personality type may affect their colonization success, suggesting that some individuals might be better invaders than others. We have recently shown that, in the invasive mosquitofish (Gambusia affinis), social personality trait was an important indicator of dispersal distance, with more asocial individuals dispersing further. Here, we tested how mean personality within a population, in addition to individual personality type, affect dispersal and settlement decisions in the mosquitofish. We found that individual dispersal tendencies were influenced by the population's mean boldness and sociability score. For example, individuals from populations with more asocial individuals or with more bold individuals are more likely to disperse regardless of their own personality type. We suggest that identifying behavioural traits facilitating invasions, even at the group level, can thus have direct applications in pest management.
Acute sun damage and photoprotective responses in whales
Authors: Martinez-Levasseur Laura M. , Gendron Diane , Knell Rob J. , O'Toole Edel A. , Singh Manuraj , Acevedo-Whitehouse Karina
Published: November 2010

Rising levels of ultraviolet radiation (UVR) secondary to ozone depletion are an issue of concern for public health. Skin cancers and intraepidermal dysplasia are increasingly observed in individuals that undergo chronic or excessive sun exposure. Such alterations of skin integrity and function are well established for humans and laboratory animals, but remain unexplored for mammalian wildlife. However, effects are unlikely to be negligible, particularly for species such as whales, whose anatomical or life-history traits force them to experience continuous sun exposure. We conducted photographic and histological surveys of three seasonally sympatric whale species to investigate sunburn and photoprotection. We find that lesions commonly associated with acute severe sun damage in humans are widespread and that individuals with fewer melanocytes have more lesions and less apoptotic cells. This suggests that the pathways used to limit and resolve UVR-induced damage in humans are shared by whales and that darker pigmentation is advantageous to them. Furthermore, lesions increased significantly in time, as would be expected under increasing UV irradiance. Apoptosis and melanocyte proliferation mirror this trend, suggesting that whales are capable of quick photoprotective responses. We conclude that the thinning ozone layer may pose a risk to the health of whales and other vulnerable wildlife.
A latitudinal gradient in rates of evolution of avian syllable diversity and song length
Authors: Weir Jason T. , Wheatcroft David
Published: November 2010

We ask whether rates of evolution in traits important for reproductive isolation vary across a latitudinal gradient, by quantifying evolutionary rates of two traits important for pre-mating isolation—avian syllable diversity and song length. We analyse over 2500 songs from 116 pairs of closely related New World passerine bird taxa to show that evolutionary rates for the two main groups of passerines—oscines and suboscines—doubled with latitude in both groups for song length. For syllable diversity, oscines (who transmit song culturally) evolved more than 20 times faster at high latitudes than in low latitudes, whereas suboscines (whose songs are innate in most species and who possess very simple song with few syllable types) show no clear latitudinal gradient in rate. Evolutionary rates in oscines and suboscines were similar at tropical latitudes for syllable complexity as well as for song length. These results suggest that evolutionary rates in traits important to reproductive isolation and speciation are influenced by latitude and have been fastest, not in the tropics where species diversity is highest, but towards the poles.
Genetic differentiation among sympatric cuckoo host races: males matter
Authors: Fossøy Frode , Antonov Anton , Moksnes Arne , Røskaft Eivin , Vikan Johan R. , Møller Anders P. , Shykoff Jacqui A. , Stokke Bård G.
Published: November 2010

Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo,
Cuculus canorus
. In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.
Has habitat heterogeneity promoted phenotypic and ecological sub‐structuring among a Coregonus lavaretus population in a large Scottish lake?
Authors: Etheridge E. C. , Harrod C. , Bean C. W. , Adams C. E.
Published: November 2010

Differences in stable‐isotope values, morphology and ecology in whitefish Coregonus lavaretus were investigated between the three basins of Loch Lomond. The results are discussed with reference to a genetic investigation to elucidate any substructuring or spawning site fidelity. Foraging fidelity between basins of Loch Lomond was indicated by δ13C and δ15N values of C. lavaretus muscle tissue. There was, however, no evidence of the existence of sympatric morphs in the C. lavaretus population. A previous report of two C. lavaretus‘species’ in Loch Lomond probably reflects natural variation between individuals within a single mixed population.
Upregulation of δ‐catenin is associated with poor prognosis and enhances transcriptional activity through Kaiso in non‐small‐cell lung cancer
Authors: Dai Shun‐Dong , Wang Yan , Zhang Jun‐Yi , Zhang Di , Zhang Peng‐Xin , Jiang Gui‐Yang , Han Yan , Zhang Sheng , Cui Quan‐Zhe , Wang En‐Hua
Published: November 2010

δ‐Catenin is the only member of the p120 catenin (p120ctn) subfamily that its primary expression is restricted to the brain. Since δ‐catenin is upregulated in human lung cancer, the effects of δ‐catenin overexpression in lung cancer still need to be clarified. Immunohistochemistry was performed to investigate the expression of δ‐catenin and Kaiso, a δ‐catenin‐binding transcription factor, in 151 lung cancer specimens. A correlation between cytoplasmic δ‐catenin and Kaiso expression was also associated with high TNM stage, lymph node metastases and poor prognosis. Co‐immunoprecipitation assay confirmed the interactions of δ‐catenin and Kaiso in lung cancer cells. In addition, gene transfection and RNAi technology were used to demonstrate that increased δ‐catenin expression was promoted, whereas its knockdown suppressed its lung cancer invasive ability. In addition, methylation‐specific PCR and ChIP assay demonstrated that δ‐catenin could regulate MTA2 via Kaiso in a methylation‐dependent manner, while it could regulate cyclin D1 and MMP7 expression through Kaiso in a sequence‐specific manner. In conclusion, a δ‐catenin/Kaiso pathway exists in lung cancer cells. Increased δ‐catenin expression is critical for maintenance of the malignant phenotype of lung cancer, making δ‐catenin a candidate target protein for future cancer therapeutics. (Cancer Sci 2011; 102: 95–103)
Phylogeny and biogeography of Carminator (Hymenoptera: Megalyridae)
Authors: MITA TOSHIHARU , KONISHI KAZUHIKO
Published: November 2010

Carminator Shaw is a small genus of parasitic wasps that is mainly distributed in Southeast Asia. Eight species are recognized here, including Carminator coronatussp.n. and Carminator gracilissp.n. A data set comprising 54 morphological characters and including all the known species of Carminator, as well as four out‐group taxa (two Cryptalyra spp., one Ettchellsia sp. and one Megalyra sp.), was assembled and analysed. Carminator is retrieved as monophyletic. All weighted analyses place Carminator affinis as the sister group to the rest of the genus. A northern clade comprising species occurring on the Japanese Isles, Taiwan and Vietnam (Carminator japonicus (Carminator gracilissp.n. (Carminator cavus + Carminator helios))) is strongly supported and nested inside the more southerly distributed species. C. helios is found on Nakanoshima Island, which emerged post‐Pliocene, and so C. helios is considered to have dispersed there via a land‐bridge connection from the Ryukyu Islands. A key to all known species of Carminator is provided.
Short Communication: Low seroprevalence of cryptococcal antigenaemia in patients with advanced HIV infection enrolling in an antiretroviral programme in Ghana
Authors: Mamoojee Yaasir , Shakoor Shaid , Gorton Rebecca L. , Sarfo Stephen , Appiah Lambert T. , Norman Betty , Balakrishnan Indran , Phillips Richard , Chadwick David
Published: November 2010

Objectives  To determine the prevalence of cryptococcal antigenaemia in a clinic population with advanced HIV infection, with a view to giving antifungal therapy to those testing positive.

Methods  Serum samples from adults with CD4 count <100 cells/mm3 presenting to a large HIV clinic in Kumasi, Ghana, were tested retrospectively for cryptococcal antigenaemia using a latex agglutination assay, and clinical and demographic data extracted from case notes.

Results  Of 92 samples tested, two were positive thus giving a prevalence of 2% (95% CI, 0–5.2%).

Conclusions  The prevalence of cryptococcal antigenaemia in patients with advanced HIV infection enrolling in an antiretroviral programme appears to be low in Kumasi, suggesting that the value of routine testing of outpatients diagnosed with advanced HIV infection may be limited in this population.
Examining the role of oxytocin in the interoceptive effects of 3,4‐methylenedioxymethamphetamine (MDMA, ‘ecstasy’) using a drug discrimination paradigm in the rat
Authors: Broadbear Jillian H. , Tunstall Brendan , Beringer Katherine
Published: November 2010

3,4‐Methylenedioxymethamphetamine (MDMA, ‘ecstasy’) use results in distinctive mood changes of a prosocial nature, most likely through its enhancement of serotonin (5HT) neurotransmission. Activation of 5HT‐1A postsynaptic receptors has been shown to stimulate the release of oxytocin in the central nervous system where it regulates aspects of mood and behavior. Using a drug discrimination paradigm, we examined whether modulation of oxytocin receptor activity would affect conditioned behavioral responses to MDMA. Male and female Sprague Dawley rats (n = 24) were trained to reliably differentiate between MDMA and a related stimulant, amphetamine (AMP), and saline using a three‐lever drug discrimination paradigm. The extent to which substitution with carbetocin (an oxytocin analog) or co‐administration with atosiban (an oxytocin receptor antagonist) affected drug‐appropriate responding was evaluated. The tricyclic antidepressant imipramine was included as a negative control. The results supported the hypotheses that substitution with an oxytocin analog (carbetocin) would partially generalize to the MDMA training cue, whereas blocking oxytocin receptors with atosiban would result in a selective disruption of MDMA––but not AMP‐appropriate responding. These findings were specific to the oxytocin receptor ligands as imipramine pre‐treatment did not affect drug‐appropriate responding. The results of this study implicate oxytocin receptor activation as a key MDMA‐specific interoceptive cue in male and female rats and support the conclusion that this is one of the features of MDMA's subjective effects that distinguishes it from AMP.
Future role of gastroenterologists in digestive oncology in the Asia Pacific region: Panir Chelvam Memorial Lecture, Asian Pacific Digestive Week 2010
Authors: Sung Joseph
Published: November 2010

There is an increasing burden in digestive cancer in the coming years. With the advancement of endoscopic therapy, new molecular target therapy and minimally invasive ablation therapy, the treatment of digestive cancer will become more complicated. In Asia where gastric cancer and hepatocellular carcinoma are still prevalent and colorectal cancer is rapidly on the rise, the need in digestive oncology will be even higher. A new subspecialty of digestive oncology will be needed from the patient's perspective, from the healthcare authority's viewpoint and for the future development of gastroenterology.
Intraoperative mydriasis by intracameral injection of mydriatic eye drops: in vivo efficacy and in vitro safety studies
Authors: Mori Yosai , Miyai Takashi , Kagaya Fumie , Nagai Nobuyuki , Osakabe Yasuhiro , Miyata Kazunori , Amano Shiro
Published: November 2010

Abstract

Background:  This study investigated the efficacy and safety of intracameral injection of commercially available eye drops containing 0.5% tropicamide and 0.5% phenylephrine hydrochloride (Mydrin‐P, Santen Pharmaceutical, Osaka, Japan).

Design:  In vitro experiment and prospective clinical study at a private hospital.

Participants and Samples:  Mydrin‐P was applied to confluent cultured human corneal endothelial cells, and the cellular morphology was examined. Clinical study subjects were 65 eyes of 65 patients that underwent phaco‐emulsification and aspiration with intraocular lens implantation and received intracameral injection of Mydrin‐P for poor mydriasis after preoperative topical instillation of mydriatics (intraocular mydriasis group; with five subgroups based on cause: diabetes, pseudo‐exfoliation, post‐surgery, uveitis, unknown). Controls, comprising 39 eyes of 39 patients, were not injected with Mydrin‐P.

Methods:  The ratio of pupillary diameter to corneal diameter was determined before and after injection of Mydrin‐P. Corneal endothelial density was measured preoperatively and 3 months and 1 year postoperatively.

Main Outcome Measures:  Pupillary diameter and corneal endothelial density.

Results:  Human corneal endothelial cell morphology was unaltered after Mydrin‐P injection. The mean ratio of the pupillary diameter to corneal diameter increased in the intraocular mydriasis group (before: 54.2 ± 4.8%, after: 58.4 ± 6.6%; P < 0.001) and in the diabetes and unknown subgroups. The corneal endothelial cell density reduction rate 3 months and 1 year after surgery was not significantly different between the intraocular mydriasis group and controls.

Conclusion:  Intracameral injection of Mydrin‐P appears to be effective and safe for dilating the pupil in cases with poor mydriasis after preoperative instillation of mydriatics.
Plasma and aqueous humour levels of ghrelin in open‐angle glaucoma patients
Authors: Katsanos Andreas , Dastiridou Anna , Georgoulias Panagiotis , Cholevas Pierros , Kotoula Maria , Tsironi Evangelia E
Published: November 2010

Abstract

Background:  To compare aqueous humour and plasma levels of ghrelin, a peptide recently identified in human eyes, in patients with open‐angle glaucoma and controls.

Design:  Cross‐sectional, controlled, hospital‐based study.

Participants:  Twenty‐four open‐angle glaucoma (17 primary open‐angle and 7 pseudo‐exfoliation glaucoma) patients and 30 controls were included. All participants were patients scheduled for cataract or glaucoma surgery. Patients with other ocular pathology, previous ocular surgery or diabetes were excluded.

Methods:  Blood samples were collected before elective surgery. Aqueous humour was aspirated from the anterior chamber through a paracentesis with a 27‐G needle under sterile conditions before any tissue manipulation. Ghrelin quantification was performed with commercially available Radioimmunoassay kits.

Main Outcome Measure:  Ghrelin levels in aqueous humour and plasma.

Results:  Plasma levels of ghrelin were 490.5 ± 156.0 pg/mL in the open‐angle glaucoma and 482.2 ± 125.4 pg/mL in the control group (Mann–Whitney test, P = 0.897). Aqueous humour levels of ghrelin were 85.5 ± 15.4 and 123.4 ± 25.5 pg/mL in the respective groups (P < 0.001). The ratio of plasma/aqueous humour ghrelin concentration was higher in the open‐angle glaucoma versus the control group (5.75 ± 1.92 vs. 4.00 ± 1.04, P < 0.001). There was no difference in aqueous humour levels of ghrelin between primary open‐angle glaucoma and pseudo‐exfoliation glaucoma patients (P = 0.494).

Conclusions:  Aqueous humour levels of ghrelin were significantly lower in open‐angle glaucoma patients, compared with controls. This difference may manifest a role of ghrelin in the disease process or a consequence of antiglaucoma treatment.
Quality of life of the most severely vision‐impaired
Authors: Crewe Julie M , Morlet Nigel , Morgan William H , Spilsbury Katrina , Mukhtar Aqif , Clark Antony , Ng Jonathon Q , Crowley Margaret , Semmens James B
Published: November 2010

Abstract

Background:  To explore the interaction between vision impairment, perceived quality of life loss and willingness to trade remaining life for vision gain.

Design:  Community‐based cross‐sectional study

Participants:  Legally blind or severely vision‐impaired people selected randomly from the Association for the Blind of Western Australia register.

Methods:  Individuals were examined by consultant ophthalmologists and completed the Impact of Vision Impairment profile quality of life assessment and a Time Trade‐Off evaluation. Vision‐related utility values were calculated. The results were analysed using univariate and multivariate regression methods.

Main Outcome Measures:  IVI Rasch Logits and TTO utility values (TTO UV).

Results:  156 people volunteered to contribute to the study. The median age was 80 (19–97) years, and 56% were female. Being legally blind (logMAR > 1) (95% CI 1.1 to 5.2, P = 0.003), clinically depressed (95% CI −11.2 to −1.8, P = 0.007) or more than 40 years of age (95% CI 0.9 to 8.1, P = 0.015) significantly lowered overall impact of vision impairment scores. The emotional domain of impact of vision impairment was associated with willingness to trade part of remaining life. A 5‐Logit increase in impact of vision impairment emotional score resulted in a 21% (95% CI 10 to 31) decrease in the odds of being likely to trade life for sight. The Australian definition of blindness compared with World Health Organisation or USA best separates those with perceived loss and appears useful in identifying vision loss‐related morbidity.

Conclusions:  These results suggest that emotional health and lack of depression are important determinants for quality and value of life.
Glutamate transporter EAAT4 in Purkinje cells controls intersynaptic diffusion of climbing fiber transmitter mediating inhibition of GABA release from interneurons
Authors: Satake Shin’Ichiro , Song Si‐Young , Konishi Shiro , Imoto Keiji
Published: November 2010

Neurotransmitters diffuse out of the synaptic cleft and act on adjacent synapses to exert concerted control of the synaptic strength within neural pathways that converge on single target neurons. The excitatory transmitter released from climbing fibers (CFs), presumably glutamate, is shown to inhibit γ‐aminobutyric acid (GABA) release at basket cell (BC)–Purkinje cell (PC) synapses in the rat cerebellar cortex through its extrasynaptic diffusion and activation of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptors on BC axon terminals. This study aimed at examining how the CF transmitter‐diffusion‐mediated presynaptic inhibition is controlled by glutamate transporters. Pharmacological blockade of the PC‐selective neuronal transporter EAAT4 markedly enhanced CF‐induced inhibition of GABAergic transmission. Tetanic CF‐stimulation elicited long‐term potentiation of glutamate transporters in PCs, and thereby attenuated the CF‐induced inhibition. Combined use of electrophysiology and immunohistochemistry revealed a significant inverse relationship between the level of EAAT4 expression and the inhibitory action of CF‐stimulation on the GABA release at different cerebellar lobules – the CF‐induced inhibition was profound in lobule III, where the EAAT4 expression level was low, whereas it was minimal in lobule X, where EAAT4 was abundant. The findings clearly demonstrate that the neuronal glutamate transporter EAAT4 in PCs plays a critical role in the extrasynaptic diffusion of CF transmitter – it appears not only to retrogradely determine the degree of CF‐mediated inhibition of GABAergic inputs to the PC by controlling the glutamate concentration for intersynaptic diffusion, but also regulate synaptic information processing in the cerebellar cortex depending on its differential regional distribution as well as use‐dependent plasticity of uptake efficacy.
Spatio‐temporal management of fisheries to reduce by‐catch and increase fishing selectivity
Authors: Dunn Daniel C , Boustany Andre M , Halpin Patrick N
Published: November 2010

Time/area closures have been widely used in fisheries management to prevent overfishing and the destruction of marine biodiversity. To a lesser degree, such spatio‐temporal management measures have been used to reduce by‐catch of finfish or protected species. However, as ecosystem‐based management approaches are employed and more fisheries are managed through multispecies, multiobjective models, the management of by‐catch will likely become increasingly important. The elimination of by‐catch has become a primary goal of the fishing policies of many countries. It is particularly relevant in the United States, as the deadline for setting annual catch limits (ACLs) in all fisheries passes in 2011. This will result in a dramatic expansion of the number of catch and by‐catch quotas. Such catch measures may result in the early closure of otherwise sustainable fisheries when by‐catch quotas are exceeded. To prevent such closures and the consequent economic hardship to fishers and the economy, it is imperative that managers be given the tools necessary to reduce by‐catch and improve fishing selectivity. Targeted spatio‐temporal fishery closures are one solution open to managers. Here, we examine how the spatio‐temporal and oceanographic characteristics of by‐catch may be used by managers to design fishery closures, and place these methods within a decision tree to assist managers to identify appropriate management measures. We argue that the current movement towards marine spatial planning (MSP) presents an important impetus to examine how we manage fisheries spatially, and we offer a first step towards the objective participation of fisheries in the MSP process.