bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishment of a human non‐small cell lung cancer cell line resistant to gefitinib
Authors: Koizumi Fumiaki , Shimoyama Tatsu , Taguchi Fumiko , Saijo Nagahiro , Nishio Kazuto
Published: March 2005

The epidermal growth factor receptor (EGFR) tyrosine‐kinase inhibitor gefitinib (Iressa®, ZD1839) has shown promising activity preclinically and clinically. Because comparative investigations of drug‐resistant sublines with their parental cells are useful approaches to identifying the mechanism of gefitinib resistance and select factors that determine sensitivity to gefitinib, we established a human non‐small cell lung carcinoma subline (PC‐9/ZD) that is resistant to gefitinib. PC‐9/ZD cells are ∼180‐fold more resistant to gefitinib than their parental PC‐9 cells and PC‐9/ZD cells do not exhibit cross‐resistance to conventional anticancer agents or other tyrosine kinase inhibitors, except AG‐1478, a specific inhibitor of EGFR. PC‐9/ZD cells also display significant resistance to gefitinib in a tumor‐bearing animal model. To elucidate the mechanism of resistance, we characterized PC‐9/ZD cells. The basal level of EGFR in PC‐9 and PC‐9/ZD cells was comparable. A deletion mutation was identified within the kinase domain of EGFR in both PC‐9 and PC‐9/ZD, but no difference in the sequence of EGFR cDNA was detected in either cell line. Increased EGFR/HER2 (and EGFR/HER3) heterodimer formations were demonstrated in PC‐9/ZD cells by chemical cross‐linking and immunoprecipitation analysis in cells unexposed to gefitinib. Exposure to gefitinib increased heterodimer formation in PC‐9 cells, but not in PC‐9/ZD cells. Gefitinib inhibits EGFR autophosphorylation in a dose‐dependent manner in PC‐9 cells but not in PC‐9/ZD cells. A marked difference in inhibition of site‐specific phosphorylation of EGFR was observed at Tyr1068 compared to other tyrosine residues (Tyr845, 992 and 1045). To elucidate the downstream signaling in the PC9/ZD cellular machinery, complex formation between EGFR and its adaptor proteins GRB2, SOS, and Shc was examined. A marked reduction in the GRB2‐EGFR complex and absence of SOS‐EGFR were observed in PC‐9/ZD cells, even though the protein levels of GRB2 and SOS in PC‐9 and PC‐9/ZD cells were comparable. Expression of phosphorylated AKT was increased in PC‐9 cells and inhibited by 0.02 μM gefitinib. But the inhibition was not significant in PC‐9/ZD cells. These results suggest that alterations of adaptor‐protein‐mediated signal transduction from EGFR to AKT is a possible mechanism of the resistance to gefitinib in PC‐9/ZD cells. These phenotypes including EGFR–SOS complex and heterodimer formation of HER family members are potential biomarkers for predicting resistance to gefitinib. © 2005 Wiley‐Liss, Inc.
Pigmentary characteristics and moles in relation to melanoma risk
Authors: Titus‐Ernstoff Linda , Perry Ann E. , Spencer Steven K. , Gibson Jennifer J. , Cole Bernard F. , Ernstoff Marc S.
Published: March 2005

Although benign and atypical moles are considered key melanoma risk factors, previous studies of their influence were small and/or institution‐based. We conducted a population‐based case‐control study in the state of New Hampshire. Individuals of ages 20–69 with an incident diagnosis of first primary cutaneous melanoma were ascertained through the New Hampshire State Cancer Registry. Controls were identified through New Hampshire driver's license lists and frequency‐matched by age and gender to cases. We interviewed 423 eligible cases and 678 eligible controls. Host characteristics, including mole counts, were evaluated using logistic regression analyses. Our results showed that pigmentary factors, including eye color (OR = 1.57 for blue eyes compared to brown), hair color (OR = 1.85 for blonde/red hair color compared to brown/black), freckles before age 15 (OR = 2.39 for freckles present compared to absent) and sun sensitivity (OR = 2.25 for peeling sunburn followed by no tan or a light tan and 2.42 for sunburn followed by tan compared to tanning immediately), were related to melanoma risk; these associations held after adjustment for sun‐related factors and for moles. In analyses confined to skin examination participants, the covariate‐adjusted effects of benign and atypical moles were moderately strong. Compared to 0–4 benign moles, risk increased steadily for 5–14 moles (OR = 1.71), 15–24 moles (OR = 3.55) and ≥ 25 moles (OR = 4.33). Risk also increased with the number of atypical moles; compared to none, the ORs for having 1, 2–3, or ≥ 4 atypical moles were 2.08, 1.84 and 3.80, respectively. Although risk was highest for those with multiple benign and atypical moles, the interaction was not of statistical significance. Our findings, arising from the first population‐ and incidence‐based study to evaluate atypical moles in relation to melanoma risk, confirm the importance of host susceptibility, represented by pigmentary factors and the tendency to develop benign or atypical moles, in the etiology of this disease. © 2005 Wiley‐Liss, Inc.
Fluctuating charge normal modes: An algorithm for implementing molecular dynamics simulations with polarizable potentials
Authors: Olano L. Renee , Rick Steven W.
Published: March 2005

A new method for performing molecular dynamics simulations with fluctuating charge polarizable potentials is introduced. In fluctuating charge models, polarizability is treated by allowing the partial charges to be variables, with values that are coupled to charges on the same molecule as well as those on other molecules. The charges can be efficiently propagated in a molecular dynamics simulation using extended Lagrangian dynamics. By making a coordinate change from the charge variables to a set of normal mode charge coordinates for each molecule, a new method is constructed in which the normal mode charge variables uncouple from those on the same molecule. The method is applied to the TIP4P‐FQ model of water and compared to other methods for implementing the dynamics. The methods are compared using different molecular dynamics time steps. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 699–707, 2005
Plasma wave excitation and charged particle acceleration in an overdense plasma
Authors: Singh Meetoo , Parashar J , Gaur N K
Published: March 2005

A laser incident on an overdense plasma, generates a space charge wave at second harmonic (2ω). The amplitude of the generated wave is resonantly enhanced at 2ω=ωp, leading to substantial reduction in the reflectivity of the plasma. The generated plasma wave can accelerate the electrons to few keV of energies.
Hearing loss in chronic myeloid leukemia
Authors: Naithani Rahul , Chandra Jagdish , Mathur N.N. , Narayan Shashi , Singh Varinder
Published: March 2005

A 12‐year‐old girl presented with abdominal pain, fever, and hearing impairment of 6 months duration. She had massive hepatosplenomegaly and anemia. On the basis of her peripheral blood and bone marrow findings, she was diagnosed as chronic myeloid leukemia (CML) in chronic phase. Her hearing was assessed by brainstem evoked responses (BERA), which showed objective improvement in hearing with hydroxyurea. The rare occurrence of deafness in CML is reviewed and possible pathogenesis is discussed. Pediatr Blood Cancer 2005; 45: 54–56. © 2005 Wiley‐Liss, Inc.
Identifying the primitive path mesh in entangled polymer liquids
Authors: Sukumaran Sathish K. , Grest Gary S. , Kremer Kurt , Everaers Ralf
Published: March 2005

Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so‐called entanglements, dominate the viscoelastic behavior of high‐molecular‐weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse‐grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer‐generated conformations of long‐chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self‐entanglements and allows us to distinguish between local self‐knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self‐knots, Nlk is significantly larger than the entanglement length Ne. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 917–933, 2005
Investigation of organic condensed phoshates
Authors: Hlel F. , Thouvenot R. , Smiri L.
Published: March 2005

Preparation, crystal structure and infra‐red absorption spectra are reported for a new organic salt of the cyclohexaphosphate, [C6H5(CH2)3NH3]6P6O18 · 2 H2O. The new compound crystallizes in the triclinic system (P$\bar 1$ space group) with Z = 2 and the following unit cell dimensions: a = 10.528(3), b = 19.183(2), c = 9.839(3) Å, α = 74.92(5), β = 117.48(6) and γ = 99.90(5)°. The structure was solved by using 6709 independent reflections down to R value of 0.039. The ring anion exhibits $\bar 1$ internal symmetry. Its main geometrical features are those commonly observed in the atomic arrangements of cyclohexaphosphates. The three dimensional cohesion of this atomic arrangement is maintained through H‐bonds between organic cations, water molecules and the external oxygen atoms of the P6O18–6 ring. The H‐bond interactions induce local distortions of the ring leading to the existence of three different types of phosphate tetrahedra.

Solid‐state 31P magic‐angle‐spinning nuclear magnetic resonance (MAS NMR), performed at 162 MHz shows three isotropic resonances at –19.8, –22.6 and –24.5 ppm, confirming the non‐equivalence of the three PO4 groups. They are characterized by different chemical shift tensor parameters, which are in agreement with the local geometrical features of the tetrahedra. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation by simulation of tests based on non‐linear mixed‐effects models in pharmacokinetic interaction and bioequivalence cross‐over trials
Authors: Panhard Xavière , Mentré France
Published: March 2005

We propose tests based on non‐linear mixed effects models (NLMEM) in pharmacokinetic interaction and bioequivalence cross‐over trials comparing two treatments or two formulations. To compare the logarithm of the area under the curve (AUC) using these models, two approaches are studied: in the first one, concentration data are analysed globally, with and without the estimation of a treatment effect; and in the second one, they are analysed separately in each treatment group with the estimation of the individual parameters. Four tests for comparison of the logarithm AUC between two treatment arms are studied: a likelihood‐ratio test (LRT), a Wald test and two tests, parametric and non‐parametric, comparing the individual Empirical Bayes (EB) estimates. These tests are adapted to the case of equivalence, except the LRT which does not have any simple extension. We evaluate by simulation of the type I error and the power for both comparison and equivalence tests. They are compared to the standard tests recommended by the FDA and the EMEA, based on non‐compartmental (NC) AUC. Trials for a usual PK model are simulated under H0 and several H1 using S‐plus software and analysed with the nlme function. Different configurations of the number of subjects (n=12, 24 and 40) and of the number of samples per subject (J=10, 5 and 3) are studied. The type I error α of LRT and Wald comparison test in the 5000 replications of interaction cross‐over trials is found to be 20.9 per cent and 21.7 per cent, respectively, in the original design (n=12, J=10), which is far superior to 5 per cent, and decreases when n increases. When n is fixed, α is found to increase with J. Power is satisfactory for both tests, after correction of the significance threshold. Results of EB and NC tests are similar with satisfactory powers and a type I error close to 5 per cent, except when J=3 for EB tests. Similar results are obtained for equivalence tests, except for EB and NC Student tests, which are not of a great interest. NC tests keep their place when the number of samples per subject J is large, but NLMEM seem useful for cross‐over studies performed in special populations where J limited; the evaluation by Monte‐Carlo simulations of empirical threshold seems however necessary because of the inflation of the type I error. Copyright © 2005 John Wiley Sons, Ltd.
Formalizing cardinality‐based feature models and their specialization
Authors: Czarnecki Krzysztof , Helsen Simon , Eisenecker Ulrich
Published: March 2005

Feature modeling is an important approach to capture the commonalities and variabilities in system families and product lines. Cardinality‐based feature modeling integrates a number of existing extensions of the original feature‐modeling notation from Feature‐Oriented Domain Analysis. Staged configuration is a process that allows the incremental configuration of cardinality‐based feature models. It can be achieved by performing a step‐wise specialization of the feature model. In this article, we argue that cardinality‐based feature models can be interpreted as a special class of context‐free grammars. We make this precise by specifying a translation from a feature model into a context‐free grammar. Consequently, we provide a semantic interpretation for cardinality‐based feature models by assigning an appropriate semantics to the language recognized by the corresponding grammar. Finally, we give an account on how feature model specialization can be formalized as transformations on the grammar equivalent of feature models. Copyright © 2005 John Wiley & Sons, Ltd.
On the occurrence and formation of multiple layers of polar mesosphere summer echoes
Authors: Hoffmann P. , Rapp M. , Serafimovich A. , Latteck R.
Published: March 2005

Polar Mesosphere Summer Echoes (PMSE) have been studied at Andenes (69°N, 16°E), Norway, using VHF radar observations from 1994–1997 and since 1999. One remarkable feature of all PMSE is the fact that the radar echoes often occur in the form of two or more distinct layers that can persist for periods of up to several hours. Until now, the layering mechanism leading to these multiple structures is not well understood. Here we are studying the occurrence and the mean altitude distribution of these multiple layer events. To discuss the processes that are potentially responsible for the creation of these multiple structures, we apply a microphysical model of the generation and growth of mesospheric ice particles under the influence of temperature and wind variations caused by a long period gravity wave. Finally, this model approach is tested with gravity wave characteristics derived from MF and VHF radar wind measurements during the PMSE observations.
Coupling of eruptions and earthquakes at Mt. Etna (Sicily, Italy): A case study from the 1981 and 2001 events
Authors: Gresta Stefano , Ghisetti Francesca , Privitera Eugenio , Bonanno Amalia
Published: March 2005

Changes in Coulomb failure stress (ΔCFS) induced by dike propagation during two flank eruptions on Mt. Etna (1981 and 2001) are calculated for the most seismically active faults on the east slope of the volcano (the right‐lateral Timpe fault system, oriented NNW‐SSE, and the left‐lateral Pernicana fault, oriented E‐W). Calculations performed using Coulomb 2.5 software indicate that intrusion of a NNW dike on the NW side of the volcano (1981 eruption) rises ΔCFS on both the Timpe and Pernicana faults. In contrast, intrusion of a N‐S dike at high elevation on the south flank (2001 eruption) rises ΔCFS only on Timpe fault System. These results are compatible with the observed pattern of seismicity, but emphasize an extremely heterogeneous state of stress on the east flank of the volcano.
UV reflecting vole scent marks attract a passerine, the great grey shrike Lanius excubitor
Authors: Probst Remo , Pavlicev Mihaela , Viitala Jussi
Published: March 2005

Diurnal raptors have been shown to use ultraviolet vision and UV‐reflecting vole scent marks to find suitable hunting areas. We studied if a passerine species, the great grey shrike Lanius excubitor that uses voles as its primary food, may also detect prey‐patches in the same way. We conducted a laboratory experiment with ten shrikes. Each individual shrike had four options to choose from: (1) scent marks with UV light, (2) scent marks without UV light, (3) clean arena with UV light, and (4) clean arena without UV light. The birds preferred the scent‐marked arena with UV light as measured by the number of scans and the time spent above it. Therefore, we suggest that great grey shrike probably uses UV cues to gain information on vole locations and abundance.
Responses of great reed warblersAcrocephalus arundinaceusto experimental brood parasitism: the effects of a cuckooCuculus canorusdummy and egg mimicry
Authors: Bártol István , Karcza Zsolt , Moskát Csaba , Røskaft Eivin , Kisbenedek Tibor
Published: March 2005

Egg rejection behaviour towards parasitic eggs was studied in a great reed warblerAcrocephalus arundinaceuspopulation in central Hungary, which was heavily (about 65%) parasitised by the common cuckooCuculus canorus. Clutches were experimentally parasitised during the egg‐laying period with artificial, moderately mimetic cuckoo eggs or with conspecific eggs that were good mimics of the hosts' eggs. Great reed warblers rejected 76.2% of the artificial cuckoo eggs, mainly by ejection, but accepted most of the conspecific eggs (87.5%). Cuckoo eggs in naturally parasitised clutches were rejected at a lower rate (32%). When, in addition to the egg mimicry experiments, a stuffed cuckoo was placed near the nest, accompanied by the recording of a female cuckoo call, hosts' rejection rate of the artificial cuckoo egg increased from 76% to 96%. The sight of the cuckoo, on the other hand, did not influence host's rejection behaviour when a conspecific egg was used in the experiment. A stuffed collared doveStreptopelia decaocto, accompanied by its call, was used as a control, and did not cause any increased rejection. Great reed warblers were more aggressive towards the cuckoo than to the dove dummy. When the cuckoo eggs in naturally parasitised clutches were exchanged with artificial cuckoo eggs, we observed no increase in the rejection rate. We conclude that great reed warblers in our heavily parasitised population are capable of detecting brood parasitism in their clutch by identifying the parasitic egg. The efficiency of this identification depends mainly on the mimicry of the foreign egg. The sight of the cuckoo at the nest may increase rejection rate by stimulus summation, and this conditional effect is mainly affected by the degree of mimicry of the parasitic egg.
Calcium shortage as a constraint on reproduction in great tits Parus major: a field experiment
Authors: Tilgar Vallo , Mänd Raivo , Mägi Marko
Published: March 2005

Several bird species breeding in acidified habitats face serious problems caused by lowered availability of calcium‐rich foods. Moreover, recent studies have revealed that calcium shortage causes phenotypic variation in certain reproductive parameters of passerines even in non‐acidified habitats. However, to date, no clear evidence has been found of the limiting effect of calcium deficiency on the reproductive output of birds breeding in such habitats. In this paper, we present experimental evidence from a long‐term study that calcium shortage may indeed limit reproductive output of passerines that breed in non‐acidified habitats. We carried out calcium‐supplementation experiments with great tits Parus major breeding in coniferous and deciduous woodlands in Estonia. Calcium‐supplemented birds laid more eggs, tended larger broods and raised more fledglings with longer tarsi compared with control birds. Calcium shortage constrained reproduction of tits not only in spring, but also in mid‐summer, during second breeding attempts. Moreover, no significant differences were detected between deciduous and coniferous habitats with respect to the effect of calcium supplements on reproductive success.
Growth rate, size, and sex ratio of last‐laid, last‐hatched offspring in the tree swallow Tachycineta bicolor
Authors: Johnson L. Scott , Wimmers Larry E. , Campbell Sara , Hamilton Lucy
Published: March 2005

In tree swallows Tachycineta bicolor, last‐laid eggs typically hatch one to two days after the other eggs in the clutch hatch, putting last‐hatched offspring at a disadvantage when competing for food delivered by parents. We studied the biology of last‐laid, last‐hatched tree swallow offspring over two years in a Wyoming, USA, population. Our first objective was to compare the growth of last‐hatched offspring to that of their earlier‐hatched nestmates. One previous study had suggested that last‐hatched, competitively disadvantaged offspring grow feathers faster than senior nestmates, even at the expense of other aspects of growth. This may allow last‐hatched offspring to fledge with senior nestmates and avoid abandonment by parents. A second objective was to determine the sex of nestlings from last‐laid eggs. If last‐laid eggs typically produce undersized, weak adults that are poor competitors for resources, and if the fitness costs of being undersized/weak are more severe for males than for females, then selection may favour having offspring from last‐laid eggs to be female. In this study, last‐laid eggs hatched in 63 of 66 (94%) nests and hatched last in 93% of cases. At hatching, offspring from last‐laid eggs weighed, on average, 63% as much as their three heaviest nestmates (range: 26–107%). Offspring from last‐laid eggs fledged from 71% of the nests that produced at least one fledgling and apparently starved to death in remaining nests. Last‐hatched offspring who were presumably at a substantial competitive disadvantage (those whose mass at hatching was no more than about 75% of the mean mass of their three heaviest nestmates), gained mass more slowly than their senior nestmates but they eventually attained the same peak mass before fledging. Last‐hatched offspring grew primary feathers more slowly than their senior nestmates although the difference in growth rate was slight (0.2 mm/d) and only marginally significant. As a group, offspring from last‐laid eggs did not differ from offspring from all other eggs in either maximum mass attained before fledging or tarsus length at fledging. This is atypical for species with asynchronous hatching and is possibly the result of another unusual trait: the tendency of parent tree swallows to distribute food equally among young within broods. The sex ratio of offspring from last‐laid eggs did not deviate from 1:1 (22 males, 21 females). Given that last‐hatched eggs do not routinely produce undersized/weak individuals in our study population, there should be little selection on parent females to bias the sex ratio of last‐laid offspring towards females.
A comparison of the annual cycles in testicular size and moult in captive European starlings Sturnus vulgaris during their first and second years
Authors: Dawson Alistair
Published: March 2005

There is considerable evidence that reproductive success improves with age in birds. It is often suggested that improved performance of older birds is because they are more experienced. Less consideration has been given to the possibility that improvements may be a consequence of age‐related changes in reproductive physiology. One factor that consistently changes with age is laying date – first year birds lay later than older birds. In European starlings Sturnus vulgaris, older males begin reproductive activity earlier than first year males and dominate available nest sites. I monitored changes in testicular volume in captive starlings exposed to natural changes in day length and temperature, from their first autumn through the next two annual cycles. Testicular maturation was advanced by 3–4 weeks in birds during their second year compared to the first, and testicular regression occurred about 2 weeks later. The period of full sexual maturation was 50% longer during the second year. The timing of the post‐nuptial moult was the same. A possible physiological mechanism to explain this is discussed. The results show that earlier reproductive activity in older birds can be explained, at least in part, by intrinsic physiological mechanisms. This does not preclude additional effects of experience of an individual in the improvement in reproductive performance between first and second year birds.
Communal singing in the cooperatively breeding subdesert mesite Monias benschi: evidence of numerical assessment?
Authors: Seddon Nathalie , Tobias Joe A.
Published: March 2005

It has long been suggested that competing groups of social animals assess one another on the basis of communal vocalisations, but so far this has only been demonstrated in mammals. We investigated this idea in the subdesert mesite, a group‐living bird that produces communal songs during aggressive territorial interactions with other groups. Where groups compete as units, differences in group size might outweigh inter‐individual differences in determining the outcome of contests. Given this species’ variable social system, we predicted that the composition of groups would also influence their resource holding potential. Playback experiments showed that the number of simulated intruders significantly influenced the strength of response by defending groups hearing the stimulus: groups were less likely to approach but gave more protracted and more communal vocal responses as the number of vocalising intruders increased. We found that the likelihood of a group approaching playback increased as the ratio between the number of males in the defending group and the number of males in the intruding group increased. Furthermore, the ratio of adult males to females in the defending group significantly affected the probability of approach, with the probability increasing as groups became more male‐biased. This finding supports the idea that the social structure of groups may be important in determining the outcome of contests between groups. Overall this study provides some indication in birds of relative numerical assessment based on vocal cues.
Evolution, biogeography, and patterns of diversification in passerine birds
Authors: Ericson Per G. P. , Irestedt Martin , Johansson Ulf S.
Published: March 2005

This paper summarizes and discusses the many new insights into passerine evolution gained from an increased general interest in avian evolution among biologists, and particularly from the extensive use of DNA sequence data in phylogenetic reconstruction. The sister group relationship between the New Zealand rifleman and all other passerines, indicates the importance of the former southern supercontinent Gondwana in the earliest evolution of this group. Following the break‐up of Gondwana, the ancestors of other major passerine groups became isolated in Australia (oscines), South America (New World suboscines), and possibly, the then connected Kerguelen Plateau/India/Madagascar tectonic plates (Old World suboscines). The oscines underwent a significant radiation in the Australo‐Papuan region and only a few oscine lineages have spread further than to the nearby Southeast Asia. A remarkable exception is the ancestor to the vast Passerida radiation, which now comprises 35% of all bird species. This group obviously benefitted greatly from the increased diversity in plant seed size and morphology during the Tertiary. The lyrebirds (and possibly scrub‐birds) constitute the sister group to all other oscines, which renders “Corvida” (sensuSibley and Ahlquist 1990) paraphyletic. Sequence data suggests that Passerida, the other clade of oscines postulated based on the results of DNA–DNA hybridizations, is monophyletic, and that the rockfowl and rock‐jumpers are the most basal members of this clade. The suboscines in the Old World (Eurylamides) and the New World (Tyrannides), respectively, are sister groups. A provisional, working classification of the passerines is presented based on the increased understanding of the major patterns of passerine evolution.
The role of predators in ship rat and house mouse population eruptions: drivers or passengers?
Authors: Blackwell G. L. , Potter M. A. , McLennan J. A. , Minot E. O.
Published: March 2005

Four hypotheses regarding the role of predation in the population dynamics of eruptive small mammal communities were tested using the small mammal assemblage found in mixed forests in New Zealand. Large‐scale (750 ha) predator removal was conducted, targeting stoats (Mustela erminea). House mouse (Mus musculus) and ship rat (Rattus rattus) population dynamics during an eruption were compared in areas with and without predator reduction. The success of predator reduction was measured by comparing live‐capture rates of predators on treatment and non‐treatment areas, and by recruitment rates of the threatened northern brown kiwi (Apteryx australis mantelli). Overall, predator reduction was successful, although there was a continual low rate of reinvasion. The predictions and results were that 1) Predators can slow but not prevent a population eruption. Supported: Populations of mice and rats erupted to high densities in areas with and without predator reduction, following synchronous southern beech (Nothofagus spp.) seeding. 2) Predators cannot truncate peak prey population size. Supported: Peak densities of mice and rats were not significantly different between treatment and non‐treatment areas. 3) Predators can hasten the rate of decline in prey populations during the crash phase. Not supported: There was evidence of populations of mice and rats declining slower in areas with predators removed, but none of the trends were significant. 4) Predators can limit low‐phase prey populations. Equivocal: Populations of rats in beech forest, and population of mice and rats in coastline habitats were significantly higher in areas with predators removed, but were not significantly different in tawa‐podocarp forest. Therefore, the role of food in driving the early stages of the mouse and rat eruption was demonstrated, but the role of predation in the decline and low phases is unclear.
Regional and local patterns in plant species richness with respect to resource availability
Authors: Cornwell William K. , Grubb Peter J.
Published: March 2005

The hump‐shaped relationship between plant species richness and productivity is a well‐established and important paradigm. While plot‐based species richness patterns on local scales have received much attention, little is currently known about species‐based patterns on a regional scale. Using Ellenberg's indicator values for 1802 plant species in central Europe, we assess the patterns in regional species richness with respect to light, water, and mineral nutrient availability – three variables that strongly influence productivity. The results of this analysis are compared to those of published studies on smaller scales leading to the following conclusions:

On a regional scale in central Europe there is a hump‐shaped relationship between soil nutrient supply and plant species richness within a given biome.

The peak in species richness for grasslands and wetlands occurs on nutrient‐poor soils, while the peak for forests is on nutrient‐rich soils.

Gradients in plant productivity controlled by different variables (i.e. water, nutrients, or disturbance) have dissimilar effects on plant species richness.
Simulation of water flow and solute transport in free‐drainage lysimeters and field soils with heterogeneous structures
Authors: Abdou H. M. , Flury M.
Published: March 2005

Lysimeters are valuable for studying the fate and transport of chemicals in soil. Large‐scale field lysimeters are used to assess pesticide behaviour and radionuclide transport, and are assumed to represent natural field conditions better than laboratory columns. Field lysimeters are usually characterized by a free‐draining lower boundary. As a result, the hydraulic gradient is disrupted, and leachate cannot be collected until the bottom of the lysimeter becomes saturated. We compared heterogeneously structured, free‐drainage lysimeters and field soils with respect to water flow and solute transport. Numerical simulations were carried out in a two‐dimensional heterogeneous sandy soil under unsaturated water flow conditions with the CHAIN_2D code. Three different soil structures (isotropic, horizontal, and vertical) were generated, and Miller–Miller similitude was used to scale the hydraulic properties of the soil. The results showed that ponding occurs at the bottom of the lysimeter for the three soil structures and that it occurred faster and was more pronounced with the vertical structure (preferential flow effect). Breakthrough curves of a conservative solute (bromide) showed that solutes are moving faster in the field than in the lysimeters. Fewer differences between lysimeters and field soils were found with the horizontal soil structure than with the isotropic and vertical structures.
Bronchiectasis in children after renal or liver transplantation: A report of five cases
Authors: Pijnenburg Mariëlle W. H. , Cransberg Karlien , Wolff Eric , Bouquet Jan , Merkus Peter J. F. M.
Published: March 2005

Abstract:  More effective immunosuppressive treatment in children following organ transplantation has significantly improved the survival of the grafts. Therefore, quality of life, long‐term prognosis and adverse drug reactions have become more important. One of the main complications of immunosuppressive drugs is infections of the respiratory tract, but irreversible damage to the airways has not been described after renal or liver transplantation. Five children following transplantation of kidney or liver were referred to the Paediatric Pulmonology department because of chronic respiratory complaints. Pulmonary function tests and HRCT scan were performed as routine patient care. Four children with a renal transplant and one with a liver transplant showed chronic bronchitis and moderate to severe airways obstruction. HRCT showed bronchiectasis in all of them. We speculate that the immunosuppressive treatment (in) directly contributes to irreversible airway damage. We recommend including follow‐up of lung function in the post‐transplantation protocol and considering bronchiectasis in case of respiratory symptoms, to try preventing further damage to the lung.
Living related small bowel transplantation in children: 3‐dimensional computed tomography donor evaluation
Authors: Panaro Fabrizio , Testa Giuliano , Balakrishnan Nikhil , Rao Bhaskara , Bogetti Diego , Jarzembowski Tomasz , Sammartino Cinzia , Sankary Howard , Benedetti Enrico
Published: March 2005

Abstract:  The evaluation of the small bowel vascular anatomy of living small bowel donors (LSBD) is usually performed with conventional angiography (CA). Recently, angio computed tomography (CT) has become a valid study of the vascular anatomy for kidney and liver living donors. We studied the applicability of angio CT with 3‐D reconstruction (3‐D‐ACT) in the evaluation of LSBD. Potential LSBDs for pediatric transplant underwent both CA and 3‐D‐ACT to evaluate the anatomy of the distal branches of the superior mesenteric artery and vein. Angio‐CT was performed with General Electric Lightspeed Scanner. The 3‐D reconstruction was performed on the TeraRecon workstation. Adverse reactions, contrast dosage, test duration, invasiveness, hospital‐stay, patient discomforts and accuracy were evaluated. Four potential donors (four female; mean age: 30.5 yr; mean BMI: 28.4) underwent both tests. Adverse reactions correlated to contrast agent used (90 mL CA, 150 mL 3‐D‐ACT) were not reported. CA required a hospitalization of 6 h as opposed to immediate discharge after the 3‐D‐ACT. The CA required the placement of transfemoral catheter and therefore greater patient discomfort than with 3‐D‐ACT. The 3‐D‐ACT arterial images were rated as equivalent to CA, however, 3‐D‐ACT venous images were rated better than the CA in all cases. CT‐angiography with 3‐D reconstruction is an acceptable method for vascular evaluation. When compared with routine angiography, it is less invasive, better tolerated and faster, but does require a significantly greater volume of venous contrast. 3‐D‐ACT also offers a better evaluation of the venous phase, and thus may become the test of choice to evaluate the vascular anatomies of LSBD candidates.
Mutations in the hydrophobic core and in the protein–RNA interface affect the packing and stability of icosahedral viruses
Authors: Lima Sheila M. B. , Peabody David S. , Silva Jerson L. , de Oliveira Andréa C.
Published: March 2005

The information required for successful assembly of an icosahedral virus is encoded in the native conformation of the capsid protein and in its interaction with the nucleic acid. Here we investigated how the packing and stability of virus capsids are sensitive to single amino acid substitutions in the coat protein. Tryptophan fluorescence, bis‐8‐anilinonaphthalene‐1‐sulfonate fluorescence, CD and light scattering were employed to measure urea‐ and pressure‐induced effects on MS2 bacteriophage and temperature sensitive mutants. M88V and T45S particles were less stable than the wild‐type forms and completely dissociated at 3.0 kbar of pressure. M88V and T45S mutants also had lower stability in the presence of urea. We propose that the lower stability of M88V particles is related to an increase in the cavity of the hydrophobic core. Bis‐8‐anilinonaphthalene‐1‐sulfonate fluorescence increased for the pressure‐dissociated mutants but not for the urea‐denatured samples, indicating that the final products were different. To verify reassembly of the particles, gel filtration chromatography and infectivity assays were performed. The phage titer was reduced dramatically when particles were treated with a high concentration of urea. In contrast, the phage titer recovered after high‐pressure treatment. Thus, after pressure‐induced dissociation of the virus, information for correct reassembly was preserved. In contrast to M88V and T45S, the D11N mutant virus particle was more stable than the wild‐type virus, in spite of it also possessing a temperature sensitive growth phenotype. Overall, our data show how point substitutions in the capsid protein, which affect either the packing or the interaction at the protein–RNA interface, result in changes in virus stability.
Numerical calculations of the pH of maximal protein stability
Authors: Alexov Emil
Published: March 2005

A large number of proteins, found experimentally to have different optimum pH of maximal stability, were studied to reveal the basic principles of their preferenence for a particular pH. The pH‐dependent free energy of folding was modeled numerically as a function of pH as well as the net charge of the protein. The optimum pH was determined in the numerical calculations as the pH of the minimum free energy of folding. The experimental data for the pH of maximal stability (experimental optimum pH) was reproducible (rmsd = 0.73). It was shown that the optimum pH results from two factors – amino acid composition and the organization of the titratable groups with the 3D structure. It was demonstrated that the optimum pH and isoelectric point could be quite different. In many cases, the optimum pH was found at a pH corresponding to a large net charge of the protein. At the same time, there was a tendency for proteins having acidic optimum pHs to have a base/acid ratio smaller than one and vice versa. The correlation between the optimum pH and base/acid ratio is significant if only buried groups are taken into account. It was shown that a protein that provides a favorable electrostatic environment for acids and disfavors the bases tends to have high optimum pH and vice versa.
Adventurers, Foreign Women and Masculinity in the Colombian Wars of Independence
Authors: Brown Matthew
Published: March 2005

This paper examines changing conceptions of honour and masculinity during the Colombian Wars of Independence in the early 19th century. It explores the position of the foreign women who accompanied British and Irish expeditions to join the war against Spanish rule, and shows how colonial, imperial and republican conceptions of masculinity were affected by the role that women played in these volunteer expeditions and in the wars in general. The paper considers women's experiences during war and peace, and examines their experiences in the light of changing conceptions of masculinity at home, in the British empire and in Hispanic America in the early nineteenth century. The social mobility of the Wars of Independence shifted the ground on which these concepts rested for all groups involved. The participation of foreign women alongside male adventurers was a further ingredient in this disorientating period.
Recasting the Role of the Intellectual: Chilean Poet Gabriela Mistral
Authors: Miller Nicola
Published: March 2005

The life and work of Gabriela Mistral, the first Latin American writer to be awarded the Nobel Prize for Literature in 1945, is examined as an example of how difficult it was for women to win recognition as intellectuals in 20th-century Latin America. Despite an international reputation for erudition and political commitment, Mistral has traditionally been represented in stereotypically gendered terms as the ‘Mother’ and ‘Schoolteacher’ of the Americas, and it has been repeatedly claimed that she was both apolitical and anti-intellectual. This article contests such claims, arguing that she was not only committed to fulfilling the role of an intellectual, but that she also elaborated a critique of the dominant male Latin American view of intellectuality, probing the boundaries of both rationality and nationality as constructed by male Euro-Americans. In so doing, she addressed many of the crucial issues that still confront intellectuals today in Latin America and elsewhere.
Fabrication and evaluation of GaN negative and bifocal microlenses
Authors: Choi H. W. , Gu E. , Liu C. , Girkin J. M. , Dawson M. D.
Published: March 2005

Methods of fabricating negative and bifocal microlens arrays have been demonstrated in this paper. The technique of photoresist molding using a sapphire positive lens template was used for the patterning of negative microlenses, while the bifocal microlens arrays were fabricated using a two-step etch process. In both cases, the lenses were etched using inductively coupled plasma. Microlenses with diameters as small as 10μm have been demonstrated and were characterized using atomic force microscopy and confocal microscopy. The lens arrays were found to be smooth, uniform, and to have focal lengths consistent with their design and calculated values.
Finite size effects in tightly meshed polymer networks
Authors: Hentschke Reinhard , Oyen Enno
Published: March 2005

Molecular dynamics computer simulations on regular, tightly meshed model networks exhibit variations of the network density with system size. We show that these variations are due mainly to network elasticity. A theoretical expression derived on the basis of the self-consistent-field approach yields finite size scaling behavior in good accord with the simulation for a wide range of thermodynamic conditions.
Generation of sub-10-fs, 5-mJ-optical pulses using a hollow fiber with a pressure gradient
Authors: Suda Akira , Hatayama Masatoshi , Nagasaka Keigo , Midorikawa Katsumi
Published: March 2005

We propose and demonstrate a pulse compression technique using a hollow fiber with a pressure gradient. This technique improves the spatial and spectral qualities of femtosecond laser pulses spectrally broadened by self-phase modulation, and allows an increase of the pulse energy for pulse compression. Using chirped mirrors for dispersion compensation, we have successfully compressed the pulse to less than 10 fs with an energy as high as 5 mJ.
Reversible self-assembly and directed assembly of DNA-linked micrometer-sized colloids
Authors: Valignat Marie-Pierre , Theodoly Olivier , Crocker John C. , Russel William B. , Chaikin Paul M.
Published: March 2005

We present a technique for the directed assembly and self-assembly of micrometer-scale structures based on the control of specific DNA linkages between colloidal particles. The use of DNA links combined with polymer brushes provides an effective way to regulate the range and magnitude of addressable forces between pairs (and further combinations) of different particles. We demonstrate that the autoassembly of alternate microbeads as well as their directed assembly, by using laser tweezers, is reversible. The key to reversibility is preventing the particles from falling into their van der Waals well at close distances. This goal is achieved by the use of adsorbed polymers that limit the number of DNA bridges to one to three between adjacent particles.
A previously uncharacterized role for estrogen receptor β: Defeminization of male brain and behavior
Authors: Kudwa Andrea E. , Bodo Cristian , Gustafsson Jan-Åke , Rissman Emilie F.
Published: March 2005

Sex differences in brain and behavior are ubiquitous in sexually reproducing species. One cause of sexual dimorphisms is developmental differences in circulating concentrations of gonadal steroids. Neonatal testes produce androgens; thus, males are exposed to both testosterone and estradiol, whereas females are not exposed to high concentrations of either hormone until puberty. Classically, the development of neural sex differences is initiated by estradiol, which activates two processes in male neonates; masculinization, the development of male-type behaviors, and defeminization, the loss of the ability to display female-type behaviors. Here, we test the hypothesis that defeminization is regulated by estrogen receptor β (ERβ). Adult male ERβ knockout and WT mice were gonadectomized, treated with female priming hormones, and tested for receptive behavior. Indicative of incomplete defeminization, male ERβ knockout mice showed significantly higher levels of female receptivity as compared with WT littermates. Testes-intact males did not differ in any aspects of their male sexual behavior, regardless of genotype. In olfactory preference tests, males of both genotypes showed equivalent preferences for female-soiled bedding. Based on these results, we hypothesize that ERβ is involved in defeminization of brain and behavior. This aspect of ERβ function may lead to developments in our understanding of neural-based sexually dimorphic human behaviors.
Task-Invariant Aspects of Goodness in Perceptual Representation
Authors: Lachmann Thomas , van Leeuwen Cees
Published: March 2005

In two experiments, pairs of Garner's classical 5-dot patterns were presented with an interstimulus interval of 500 ms in a same–different task in which a physical sameness criterion was used: Rotated or reflected versions of the same pattern were rated as different. Patterns varied in “goodness” according to Garner's equivalence set size measure. Both first and second pattern goodness affected reaction time and accuracy. This result and fits of models to reaction time data indicate that equivalence set representations are used in the task, as in a related categorical matching task in previous studies. Two effects were observed that contrast with the categorical matching task: One is a conflict between the need to respond different to patterns that are categorically equivalent under the equivalence set representation; the other is that extra time is needed for rechecking of the representation if pattern structures are hard to distinguish. In combination with previous studies, the present results show that even though the processes differ, the same representational mechanism is used across tasks.