bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacogenetics in drug regulation: promise, potential and pitfalls
Authors: Shah Rashmi R 
Published: July 2005

Pharmacogenetic factors operate at pharmacokinetic as well as pharmacodynamic levels—the two components of the dose–response curve of a drug. Polymorphisms in drug metabolizing enzymes, transporters and/or pharmacological targets of drugs may profoundly influence the dose–response relationship between individuals. For some drugs, although retrospective data from case studies suggests that these polymorphisms are frequently associated with adverse drug reactions or failure of efficacy, the clinical utility of such data remains unproven. There is, therefore, an urgent need for prospective data to determine whether pre-treatment genotyping can improve therapy. Various regulatory guidelines already recommend exploration of the role of genetic factors when investigating a drug for its pharmacokinetics, pharmacodynamics, dose–response relationship and drug interaction potential. Arising from the global heterogeneity in the frequency of variant alleles, regulatory guidelines also require the sponsors to provide additional information, usually pharmacogenetic bridging data, to determine whether data from one ethnic population can be extrapolated to another. At present, sponsors explore pharmacogenetic influences in early clinical pharmacokinetic studies but rarely do they carry the findings forward when designing dose–response studies or pivotal studies. When appropriate, regulatory authorities include genotype-specific recommendations in the prescribing information. Sometimes, this may include the need to adjust a dose in some genotypes under specific circumstances. Detailed references to pharmacogenetics in prescribing information and pharmacogenetically based prescribing in routine therapeutics will require robust prospective data from well-designed studies. With greater integration of pharmacogenetics in drug development, regulatory authorities expect to receive more detailed genetic data. This is likely to complicate the drug evaluation process as well as result in complex prescribing information. Genotype-specific dosing regimens will have to be more precise and marketing strategies more prudent. However, not all variations in drug responses are related to pharmacogenetic polymorphisms. Drug response can be modulated by a number of non-genetic factors, especially co-medications and presence of concurrent diseases. Inappropriate prescribing frequently compounds the complexity introduced by these two important non-genetic factors. Unless prescribers adhere to the prescribing information, much of the benefits of pharmacogenetics will be squandered.
Discovering highly predictive genotype–phenotype associations during drug development and demonstrating their clinical validity and utility in well-designed prospective clinical trials will no doubt better define the role of pharmacogenetics in future clinical practice. In the meantime, prescribing should comply with the information provided while pharmacogenetic research is deservedly supported by all concerned but without unrealistic expectations.
Pathogen clumping: an explanation for non‐linear transmission of an insect virus
Authors: D'Amico Vincent , Elkinton Joseph S. , Podgwaite John D. , Buonaccorsi J. P. , Dwyer Greg 
Published: July 2005

Abstract.  1. Previous work has shown that transmission of some insect pathogens is a non‐linear process. A number of hypotheses have been put forward as explanations for this phenomenon; however, none have proven wholly satisfactory. Here we test the effects on transmission of spatial distribution of an insect virus by testing whether or not experimental manipulations of pathogen clumping lead to different values of a clumping parameter. The gypsy moth nucleopolyhedrovirus (LdMNPV) was used, which is transmitted when larvae consume virus released from previously infected larvae that have died on foliage.2. It was found that even when virus densities on foliage were equal, overall mortality was lower when virus‐killed cadavers were clumped on foliage.3. Non‐linearity is more pronounced when cadavers are clumped than when they are placed at random on the foliage. Placement of droplets containing LdMNPV on foliage resulted in more linear transmission compared with cadavers.4. Spatial clumping of viral inoculum thus provides part of the explanation for non‐linear transmission in this system. The ultimate explanation for non‐linear transmission is likely to involve some combination of spatial clumping and heterogeneity in behaviours such as feeding rate or the ability to avoid pathogen.
Host selection by winged colonisers within the Myzus persicae group: a contribution towards understanding host specialisation
Authors: Margaritopoulos J. T. , Tsourapas C. , Tzortzi M. , Kanavaki O. M. , Tsitsipis J. A. 
Published: July 2005

Abstract.  1. Myzus persicae sensu lato demonstrates considerable genetic variation in respect to adaptation to host plants. The subspecies M. persicae nicotianae shows a preference for tobacco, while M. persicae sensu stricto (s. str.) for other herbaceous plants. Given that winged colonisers of several aphid species play an important role in selecting host plants, here their role in the host specialisation observed in M. persicae was examined in choice and no‐choice tests conducted outdoors, in performance studies, and in DC Electrical Penetration Graph (DC‐EPG) studies.2. In outdoor choice tests, 77% of spring migrants of M. persicae nicotianae chose tobacco, whereas equal proportions of M. persicae s. str. selected tobacco and pepper. In no‐choice tests, spring migrants settled more quickly after alighting on host rather than on non host plants, and significantly more alate M. persicae s. str. (27%) than M. persicae nicotianae (2%) left tobacco after walking briefly on the leaf surface, whilst no significant differences were found on pepper. Cross‐host transfers significantly reduced the fecundity of both summer and spring migrants of the two subspecies. Finally, the results of no‐choice tests and DC‐EPG studies showed that winged aphids distinguished their host through cues located on the plant surface or in subcutaneous tissues perceived prior to the initiation of feeding.3. This study demonstrates the important role of winged colonisers in the evolution of host specialisation in M. persicae. The multifarious divergent selection that the two host forms experience, i.e. the selection against cross‐migrants and their subsequent generations, is a crucial factor involved in the development and maintenance of host specialisation and promotes the parallel evolution of improved host‐recognition ability.
Survival and reproduction when food is scarce: implications for a lekking Hawaiian Drosophila
Authors: Jones Therésa M. , Widemo Fredrik 
Published: July 2005

Abstract.  1. In insects, larval diet can have a major impact on development, survival, and reproductive success. However, resource availability at the adult phase of the life cycle is also likely to have strong effects in species where there is an extended period of sexual maturation following adult eclosion.2. The effect of diet on the survival and reproductive success of the lekking Hawaiian fruit fly, Drosophila grimshawi, was explored. Two generations of emerging adults were exposed to one of two feeding regimes: ‘constant’ and ‘varied’ (corresponding to food ‘each day’ or ‘every other day’ respectively). The impact of resource availability on survival and reproductive success in each generation was then investigated.3. The probability of survival to 5 weeks old was higher for individuals fed a constant diet than individuals fed a varied diet, but was comparable for males and females.4. There was a significant maternal effect on offspring survival. Offspring whose mothers were reared on a constant feeding regime had higher survival than offspring whose mothers were reared on a varied diet.5. There was no relationship between feeding regime and the quantity of pheromones deposited by males (a measure of male reproductive investment); however F2 sons were more likely to deposit pheromones and deposited a larger quantity of pheromone than their F1 sires. The number and sex ratio of offspring (a measure of female reproductive effort) emerging from the F1 generation was unrelated to maternal or paternal feeding regime.6. The implications of variation in the foraging environment for mate choice in D. grimshawi are discussed.
Influence of egg size differences within egg clutches on larval parameters in nine libellulid species (Odonata)
Authors: Schenk Kamilla , Söndgerath Dagmar 
Published: July 2005

Abstract. 1. In libellulids, egg size differs between species and populations. There are also size differences within egg clutches of individual females.2. Past experiments suggest that there are two different types of egg clutches in libellulids. Egg size decreases significantly during oviposition in species that perform non‐contact guarding during oviposition. In contrast, in species ovipositing in tandem, egg size is randomly distributed.3. This study deals with the possible consequences of egg size variation within the different egg clutch types. The study examined whether there is a correlation between egg development time, offspring sex or larval size and egg size.4. The current experiments were conducted in Namibia and Germany. Five non‐contact guarding and four tandem guarding libellulid species were used.5. In some species larger eggs needed more time to develop, in some species no correlation between egg size and egg development time could be found, whereas in other species larger eggs developed faster.6. The sex ratio was biased towards females inLeucorrhinia dubiaand inSympetrum striolatumand egg size was not associated with gender.7. In both egg clutch types larger eggs resulted in larger larvae. In this study, evidence was found that the effects of egg size diminished with progressing larval development under good conditions. However, it is possible that the effects may have a greater influence under harsh circumstances.
A method for rapidly mass laser‐marking individually coded ground beetles (Coleoptera: Carabidae) in the field
Authors: Griffiths Georgianne J. K. , Alexander Colin J. , Birt Andrew , Holland John M. , Kennedy Peter J. , Perry Joe N. , Preston Rick , Winder Linton 
Published: July 2005

Abstract.  1. A laser‐marking technique is described that may be used to rapidly mass‐mark and individually code insects in the field. In this study, ground beetles were marked but the method is applicable to a wide range of organisms with a hard exoskeleton or shell.2. In a field‐scale capture–recapture study conducted in winter wheat, 8266 beetles were coded. Individuals marked in the first week of the trial and recaptured 2 months later retained their codes, which were therefore considered permanent.3. Assemblages were dominated numerically by Pterostichus cupreus, which formed more than 98% of the total captures. Of the 8046 released P. cupreus, 2269 were recaptured. As an illustration of the use of these data, the POPAN parameterisation of the Jolly–Seber model was used to estimate a whole‐field population of 17 237 individuals, equating to a density of 0.46 beetles m−2.
The effect of conspecifics on individual male movement in Roesel's bush cricket, Metrioptera roeseli
Authors: Berggren Åsa 
Published: July 2005

Abstract.  1. Individual movement behaviours of male Roesel's bush crickets were compared between individuals experimentally released with or without conspecifics.2. Differences in movement behaviour were recorded between the groups, with individuals released with conspecifics moving faster and further.3. The study shows that behavioural interactions between individuals need to be considered in population modelling. Empirical movement data derived from lone individuals would result in a significant underestimation of both population expansion (−38.1%) and inter‐patch movement (−35.8%).
The effects of foliar pubescence and nutrient enrichment on arthropod communities ofMetrosideros polymorpha(Myrtaceae)
Authors: Gruner Daniel S. , Taylor Andrew D. , Forkner Rebecca E. 
Published: July 2005

Abstract. 1. Nutrient resource availability and host‐plant foliar pubescence both influence arthropod food webs, but multifactor studies are needed to understand their interdependence and relative importance. Arthropods were sampled by clipping foliage fromMetrosideros polymorpha(Myrtaceae) trees of pubescent, glabrous, and intermediate leaf forms on fertilised and unfertilised plots.2. Fertilisation decreased leaf mass per area (LMA) but did not change the relative mass of pubescence within leaf morphological classes.3. Fertilisation increased densities of individuals in four taxonomic orders, densities of individuals and species of all trophic levels, and the biomass of Collembola and Homoptera. Herbivore relative diversity (ShannonH′) also increased with fertilisation, but detritivore diversity declined due to increasing dominance ofSalina celebensis(Schaeffer) (Collembola).4. Detritivore density, driven again byS. celebensis, increased with decreasing leaf pubescence, but Heteroptera and Acari were most abundant on the intermediate pubescence class, and Psocoptera density and biomass increased with increasing pubescence. Trophic‐level species density did not change with leaf morphological class, but relative diversity of all arthropods and of detritivores increased with increasing pubescence.5. Both resource availability and leaf pubescence affectedMetrosiderosarthropod communities. However, the pervasive positive influence of fertilisation did not translate to compositional shifts, and there were no interactions with leaf morphological class. In contrast, the effects of leaf pubescence on arthropod density, biomass, and diversity were more restricted taxonomically, and non‐parametricmanovaand redundancy analyses demonstrated significant differentiation in community composition on the pubescent morphology.
Transmission dynamics of an iridescent virus in an experimental mosquito population: the role of host density
Authors: Marina Carlos F. , Fernández‐Salas Ildefonso , Ibarra Jorge E. , Arredondo‐Jiménez Juan I. , Valle Javier , Williams Trevor 
Published: July 2005

Abstract. 1. The transmission of insect pathogens cannot be adequately described by direct linear functions of host and pathogen density due to heterogeneity generated from behavioural or physiological traits, or from the spatial distribution of pathogen particles. Invertebrate iridescent viruses (IIVs) can cause patent and lethal infection or a covert sub‐lethal infection in insects.Aedes aegyptilarvae were exposed to suspensions of IIV type 6 at two densities. High larval density increased the prevalence of aggression resulting in potentially fatal wounding.2. The overall prevalence of infection (patent + covert) was positively influenced by host density and increased with exposure time in both densities. The survival time of patently infected insects was extended by ≈ 5 days compared with non‐infected insects.3. Maximum likelihood models based on the binomial distribution were fitted to empirical results. A model incorporating heterogeneity in host susceptibility by inclusion of a pathogen‐free refuge was a significantly better fit to data than an all‐susceptible model, indicating that transmission is non‐linear. The transmission coefficient (υ) did not differ with host density whereas the faction of the population that occupied the pathogen‐free refuge (ΠR) was significantly reduced at high host density compared with the low density treatment.4. The transmission of free‐living infective stages of an IIV inAe. aegyptilarvae is non‐linear, probably because of density‐related changes in the frequency of aggressive encounters between hosts. This alters host susceptibility to infection and effectively reduces the proportion of hosts that occupy the pathogen‐free refuge.
Egg maturation strategy and its associated trade‐offs: a synthesis focusing on Lepidoptera
Authors: Jervis Mark A. , Boggs Carol L. , Ferns Peter N. 
Published: July 2005

Abstract. 1. Insects vary considerably between and within orders, and even within the same genus, in the degree to which the female's lifetime potential egg complement is mature when she emerges as an adult.2. The ‘ovigeny index’ (OI) – the number of eggs females have ready to lay divided by the lifetime potential fecundity – quantifies variation in the degree of early life concentration of egg production, and also variation in initial reproductive effort.3. Here, an integrated set of hypotheses is presented, based on a conceptual model of resource allocation and acquisition, concerning trade‐offs at the interspecific level between initial investment in egg production (as measured by OI) and other life‐history traits in holometabolous insects.4. The evidence supporting each of these hypotheses is reviewed, and particular attention is paid to the Lepidoptera, as relevant life‐history data are rapidly accumulating for this ecologically and economically important group.5. There is evidence at the interspecific level supporting: (i) a link between OI and a trade‐off between soma and non‐soma in Trichoptera and Hymenoptera (the proportionate allocation to soma decreases with increasing OI); (ii) a negative correlation between OI and dependency on external nutrient inputs (via adult feeding) in Hymenoptera and in Lepidoptera; (iii) a negative correlation between OI and the degree of polyandry (and nuptial gift, i.e. spermatophore, use) in Lepidoptera; (iv) negative correlations between OI and resource re‐allocation capabilities (egg and thoracic musculature resorption) in Hymenoptera and in Lepidoptera; (v) a negative correlation between lifespan and OI in Trichoptera, Hymenoptera, and Lepidoptera, indicating a cost of reproduction; (vi) a link between winglessness and an OI of one in Lepidoptera; (vii) a negative correlation between OI and the degree of female mobility in winged Lepidoptera; and (viii) a negative correlation between OI and larval diet breadth (as mediated by oviposition strategy) in Lepidoptera.
Paternity analysis in the golden egg bug using AFLPs: do the males preferentially accept their true genetic offspring?
Authors: García‐González F. , Núñez Y. , Ponz F. , Roldán E. R. S. , Gomendio M. 
Published: July 2005

Abstract.  1. The evolution of parental care and intraspecific parasitism involve conflicts of interest between mothers and other potential care givers who contribute to enhance offspring survival. In the golden egg bug, Phyllomorpha laciniata Villers (Heteroptera: Coreidae), females lay eggs on conspecifics and on plants. The adaptive significance of egg carrying in this species has been the subject of some controversy, which can only be resolved by determining the genetic relationship between the eggs and the adult who carries them. This study examined whether male acceptance of true genetic offspring occurs with a higher frequency than that expected from random oviposition on conspecifics.2. Paternity analysis, using Amplified Fragment Length Polymorphism (AFLP) markers, was conducted on eggs carried by males housed with field‐mated females.3. Out of the total number of eggs sired by males in the experimental groups, the proportion of eggs carried by males that were their true genetic offspring was 30.8%.4. Monte Carlo methods show that the probability of a male accepting an egg that is his true genetic offspring is higher than expected if females dumped eggs on males at random.5. These results suggest that paternal care plays an important role in the maintenance of male egg carrying in this species. In addition, the methodology developed may become useful in determining true genetic parents in other species in which neither the father nor the mother can be determined by observational methods.
Movement and dispersal patterns in the bush cricketPholidoptera griseoaptera: the role of developmental stage and sex
Authors: Diekötter Tim , Csencsics Daniela , Rothenbühler Carmen , Billeter Regula , Edwards PETER J. 
Published: July 2005

Abstract. 1. To persist in a highly fragmented environment, such as the intensively used agricultural landscapes of Europe, species may need to successfully disperse between sub‐populations. This paper describes a capture – mark – resight experiment to investigate movement and dispersal patterns of the flightless bush cricket speciesPholidoptera griseoaptera.2. Movement parameters showed little difference between juveniles and imagos as well as between males and females. Both developmental stages and sexes moved considerable distances, were cap\able of crossing habitat boundaries, and showed successful inter‐patch dispersal through the agricultural matrix.3. The results suggest thatP. griseoapteraexhibits movement behaviours that compensate for its inability to fly. It was concluded that the good dispersal ability exhibited by animals of both sexes and developmental stage is an important factor allowingP. griseoapterato persist in fragmented agricultural landscapes.
Horizontal transmission ofWolbachiain aDrosophilacommunity
Authors: Haine Eleanor R. , Pickup Nicola J. , Cook James M. 
Published: July 2005

Abstract. 1. Wolbachiabacteria are reproductive parasites of arthropods and infect an estimated 20% of all insect species worldwide. In order to understand patterns ofWolbachiainfection, it is necessary to determine how infections are gained or lost.Wolbachiatransmission is mainly vertical, but horizontal transmission between different host species can result in new infections, although its ecological context is poorly understood. Horizontal transmission is often inferred from molecular phylogenies, but could be confounded by recombination between differentWolbachiastrains.2. This study addressed these issues by using three genes:wsp,ftsZ, andgroE, to studyWolbachiainfections in fruit‐ and fungus‐feedingDrosophilacommunities in Berkshire, U.K.3. Identical sequences were found for all three genes inDrosophila ambiguaandDrosophila tristis.This suggests horizontal transmission ofWolbachiabetween these two previously unstudiedDrosophilaspecies, which may be the result of the two host species sharing the same food substrates or parasites.4. Wolbachiainfections might be lost from species due to curing by naturally occurring antibiotics and the presence of these is likely to vary between larval food substrates.5. It was investigated whetherWolbachiaincidence was lower in fungus‐feeding than in fruit‐feedingDrosophilaspecies, but no significant difference based on food substrate was found.
Host age and fitness‐related traits in a koinobiont aphid parasitoid
Authors: Colinet H. , Salin C. , Boivin G. , Hance TH. 
Published: July 2005

Abstract.  1. Trade‐offs play a key role in species evolution and should be found in host–parasitoid interactions where the host quality may differ between host age categories.2. The braconid wasp, Aphidius ervi, is a solitary endoparasitoid that allows its aphid hosts to continue to feed and grow after parasitisation. The hypotheses that host age influences their quality and that female parasitoids exploit their hosts based on that quality were tested under laboratory conditions using no‐choice tests.3. Aphidius ervi females accepted the aphid Myzus persicae for oviposition and their progeny developed successfully in all host ages. The fitness‐related traits of parasitoids did not increase linearly with the host age in which they developed. Host quality was found to be optimal at intermediate host ages and the females preferred to parasitise these hosts. The shortest progeny development time and a more female‐biased sex ratio were observed in hosts of intermediate age.4. This study suggests the existence of multiple interactive trade‐offs occurring during host–parasitoid interactions according to host age related quality.